Adjustable soft tissue balancing devices and systems for total shoulder arthroplasty

Abstract

An adjustable trial device (100) is provided for determining an optimal configuration for a component of a total shoulder arthroplasty implant. The device includes a housing (110) defining an outer bone-facing surface (111), an implant interface surface (142), and a plurality of actuators (130) positioned within the housing. The plurality of actuators is operable to adjust a position and / or orientation of the implant interface surface. In some examples, the principles underlying the design of the adjustable trial device can be implemented in an adjustable glenoid trial (101) and / or an adjustable humeral head trial (200) for an anatomic total shoulder arthroplasty system. Alternatively, the adjustable trial device can be implemented in an adjustable humeral liner trial (300) and / or an adjustable glenosphere trial (400) for a reverse total shoulder arthroplasty system.

Description

ADJUSTABLE SOFT TISSUE BALANCING DEVICES AND SYSTEMS FOR TOTAL SHOULDER ARTHROPLASTYCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a non-provisional patent application claiming priority to, and the benefit of the filing date of, U.S. provisional patent application number 63 / 606,845, which was filed December 6, 2023, entitled “Adjustable Glenoid Trial,” the entire contents of which are incorporated herein.FIELD OF THE DISCLOSURE

[0002] The present disclosure relates generally to orthopedic devices and methods for total shoulder arthroplasty. More particularly, the present disclosure relates to device and methods for determining an optimal configuration for a component of an anatomic or reverse shoulder implant.BACKGROUND OF THE DISCLOSURE

[0003] Total shoulder arthroplasty (TSA) is a common treatment for glenohumeral arthritis. Such surgery can be a challenging procedure to perform compared to other arthroplasties, however, in terms of optimizing the seating of the implants in the glenoid vault and preservation and rehabilitation of the surrounding soft tissues (e.g., muscles, ligaments and tendons). Modern shoulder replacement implants are generally of two designs: anatomic and reverse. Anatomic shoulder implants are intended to restore the natural kinematics of the shoulder by replacing the humeral head and glenoid with similarlyshaped prosthetic designs that recreate normal anatomy. The anatomic shoulder implant often has a spherical humeral head and a shallow concave glenoid that articulates with the spherical head. After the intact humeral head is resected, the anatomic shoulder implants have a stem configured to be securely placed down the shaft of the humerus and the spherical head is often fixed to the stem via a mechanical taper press fit. The glenoid prosthetic component, usually made from a polymer such as ultra-high molecular weight polyethylene (UHMWPE) is either cemented directly into the remaining intact glenoid or affixed to a metallic tray, which is secured to the native glenoid bone using bone screws, cement, or similar attachment methods.

[0004] Reverse shoulder implants are different from the anatomic shoulder implants in that the spherical surface is placed on the remaining intact glenoid and the concave articular surface is placed on the humerus. The reverse shoulder also has a stem configured to be securely placed down the shaft of the humerus. The polymer concave articular surface is fixed to the stem using a mechanical lock. The spherical head, in the reverse shoulder, is fixed to the remaining intact glenoid using a base plate.

[0005] In either configuration, the components of the implant must be sized and configured to provide a desired fit with the patient’s anatomy. In this regard, parameters relevant to the prosthesis design can include height, width, articular surface area, inclination, vault size and shape, center of the head, and version. Typically, these parameters are templated pre-operatively from X-rays or CT scans.

[0006] Soft tissue tension plays a pivotal role in the success of shoulder replacement procedures. Pre-setting the correct passive tension in the neighboring muscles in theshoulder joint (e.g., deltoid and rotator cuff) is considered as important as the orientation and fixation of the implant components given that the movement achieved on the operating table will never be surpassed post operatively. Therefore, the surgeon must restore enough soft tissue balance so the unconstrained implant in total shoulder arthroplasty can be moved while remaining stable.

[0007] To date, surgeon determination of the optimal construct tension after reduction during total shoulder replacement surgery remains largely qualitative to avoid complications related to (a) excessive soft tissue tension (e.g., acromial fractures, early wear of polyethylene, postoperative pain and stiffness) and (b) lack of soft tissue tension, and more specifically insufficient deltoid tension associated with prosthetic instability. This qualitative determination is achieved subjectively through a combination of the following approaches; (a) individual experience derived from ease of reduction, (b) selection of different implant designs, sizes, placements, and orientations, (c) passive range of motion assessment on the table, e.g. static and dynamic activities of daily living, (d) presence or absence of boney impingement, (e) intraoperative parameters such as residual intact rotator cuff and / or other muscle relaxation related to anesthesia, type of arthrosis, degree of wear of the glenoid, preoperative function, prior surgery, and (f) “shuck tests” involving traction along the longitudinal axis of the humerus to assess for pistoning and checking the resting tension within the conjoint tendon during trial component upsizing and down-sizing, which is clinically described as generally either “loose,” “normal,” or “tight.” The current approach to assessing tension thus remains a trial-and-error process, relying on subjective evaluations.

[0008] Additionally, existing trial implant systems have limited adjustment capabilities, which can result in complications such as dislocations and bone fractures. The sequence of trial reduction involves dislocating the joint and inserting different size components, and then reducing it according to subjective assessment of cuff tension and trial component stability. For both anatomic (aTSA) and reverse (rTSA) shoulder procedures, humeral head osteotomy and component size contribute to soft tissue tension, motion, and stability. Once the trial components have been inserted, the surgeon then assesses the position, stability, and soft tissue balance of the trial components by placing the limb in different poses and repeatedly articulating the joint through varying degrees of joint angles (e.g., flexion, internal rotation, extension, external rotation). Assessing soft tissue tension and the limits of a patient’s range of motion is largely dependent upon surgeon experience, skill, judgement and “feeling” involved forces and their intensities using fingers as natural haptic feedback. Once the trial implants are deemed to have been correctly positioned with the correct soft tissue tensioning, the trial implants are exchanged with the final implants.

[0009] To remove the reliance on subjective assessments of position, stability, and soft tissue balance of a trial component, it would be advantageous for trial components to be able to adjust the implant tension more systematically without requiring the placement of different trial configurations that require multiple reductions. It would also be advantageous to determine a patient-specific inflection point between an under-tensioned and over-tensioned glenhumeral joint, which can be determined from a force vs. index position (e.g., liner height, glenosphere diameter, height, and offset) graph for a givenmotion arc. A patient-specific inflection point would optimize both humeral and scapulacentric lateralization for a reverse shoulder procedure leading to optimize shoulder function. It is with respect to these and other considerations that the present disclosure may be useful.SUMMARY OF THE DISCLOSURE

[0010] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

[0011] An adjustable trial device for use in determining an optimal configuration for a component of a total shoulder arthroplasty implant is disclosed. In some examples, the device includes a housing defining an outer bone-facing surface, an implant interface surface, and a plurality of actuators positioned within the housing. The plurality of actuators can be operable to adjust a position or orientation of the implant interface surface.

[0012] A method for determining an optimal configuration for a component of a total shoulder arthroplasty implant is also disclosed. In some examples, the method includes a step of positioning an adjustable trial device against a prepared bone surface, wherein the adjustable trial device comprises a housing defining an outer bone-facing surface and an implant interface surface. The method can further include adjusting a position or orientation of the implant interface surface with respect to the bone surface by actuating one or more of a plurality of actuators positioned within the housing.

[0013] In any preceding or subsequent example, each of the plurality of actuators includes a pulley wheel coupled to the leadscrew and one or more solenoid coupled to the pulley wheel. In this configuration, actuation of the one or more solenoids rotates the pulley wheel. In some examples, the one or more solenoid is coupled to the pulley wheel by a coil of wire that is wound around the ratchet pulley wheel, and actuation of the one or more solenoids rotates the pulley wheel by applying a pull force to the coil of wire.

[0014] Alternatively, each of the plurality of actuators includes a primary actuator that is linearly movable within the housing and a plurality of push-rods coupled to the primary actuator. In some such examples, the implant interface surface comprises a plurality of surface segments that together define the implant interface surface, where each of the plurality of push-rods is connected to one of the plurality of surface segments. In this arrangement, movement of the primary actuator causes a corresponding movement of the plurality of push-rods to adjust a position of the plurality of surface segments of the implant interface surface.

[0015] In any preceding or subsequent example, one or more load measuring sensor is provided in communication with the implant interface surface, where each load measuring sensor is configured to measure forces applied to the implant interface surface.

[0016] Examples of the present disclosure provide numerous advantages. For example, the adjustable trial device can be implemented as an adjustable glenoid trial and / or an adjustable humeral head trial for an anatomic total shoulder arthroplasty system or as an adjustable humeral liner trial and / or an adjustable glenosphere trial for a reverse total shoulder arthroplasty system. These trials offer more control for optimal seating of theimplant to ensure the correct level of soft tissue tightness in the glenohumeral joint. In some particular examples, a multi-segmented design increases the load sensing capability across the glenohumeral joint, which enables compressive forces to be captured over a greater surface area, particularly at the rims under extreme rotation.

[0017] Further features and advantages of at least some of the examples of the present disclosure, as well as the structure and operation of various examples of the present disclosure, are described in detail below with reference to the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By way of example, specific examples of the disclosed device will now be described, with reference to the accompanying drawings, in which:

[0019] FIG. 1A illustrates a bottom perspective view of an adjustable glenoid trial in accordance with one or more features of the present disclosure;

[0020] FIG. IB illustrates a side exploded perspective view of an adjustable glenoid trial in accordance with one or more features of the present disclosure;

[0021] FIG. 2 illustrates a side perspective view of a housing of an adjustable glenoid trial in accordance with one or more features of the present disclosure;

[0022] FIGS. 3A and 3B are graphs illustrating parameters used to describe the loadrotation characteristics derived from the dynamic assessments during maximum internal / external rotation and forward elevation in accordance with one or more features of the present disclosure;

[0023] FIG. 4A is a side perspective view of a trial assembly positioned to measure humeral head forces in accordance with one or more features of the present disclosure;

[0024] FIG. 4B is a graph showing load measurement curves associated with glenohumeral joint forces measured during passive range of motion testing;

[0025] FIG. 5 is a side perspective view of an inflatable glenoid trial in accordance with one or more features of the present disclosure;

[0026] FIG. 6 is a side perspective view of an inflatable glenoid trial positioned between the humeral head and the surface of the glenoid in accordance with one or more features of the present disclosure;

[0027] FIGS. 7A and 7B are side perspective views of an adjustable humeral head trial in accordance with one or more features of the present disclosure;

[0028] FIG. 8 is a bottom plan view of an adjustable humeral head trial in accordance with one or more features of the present disclosure;

[0029] FIGS. 9A and 9B are side perspective views of adjustable humeral head trials in accordance with one or more features of the present disclosure;

[0030] FIG. 10 is a side cutaway view of an adjustable humeral head trial in accordance with one or more features of the present disclosure;

[0031] FIGS. HA and llB are side perspective views of components of an adjustable humeral head trial in accordance with one or more features of the present disclosure;

[0032] FIG. 12 is a side perspective view of an adjustable humeral liner trial in accordance with one or more features of the present disclosure;

[0033] FIG. 13 is a side cutaway view of an adjustable humeral liner trial in accordance with one or more features of the present disclosure;

[0034] FIGS. 14A and 14B are side views of an articulating liner of an adjustable humeral liner trial in accordance with one or more features of the present disclosure;

[0035] FIGS. 15A through 15C are side views of an adjustable humeral liner trial in accordance with one or more features of the present disclosure;

[0036] FIG. 16 is a top plan view of internal elements of an adjustable humeral liner trial in accordance with one or more features of the present disclosure;

[0037] FIG. 17 is a partial side cutaway view of internal elements of an adjustable humeral liner trial in accordance with one or more features of the present disclosure;

[0038] FIG. 18 is a side perspective view of a glenosphere component of a reverse shoulder replacement implant in accordance with one or more features of the present disclosure;

[0039] FIG. 19A is a side perspective view of a glenosphere component of a reverse shoulder replacement implant in accordance with one or more features of the present disclosure;

[0040] FIG. 19B is a side cutaway view of a glenosphere component of a reverse shoulder replacement implant in accordance with one or more features of the present disclosure;

[0041] FIG. 20 is a flow chart illustrating steps in a method for glenoid trialing in accordance with one or more features of the present disclosure;

[0042] FIGS. 21A and 21B are side perspective views of a trial assembly positioned to optimize the version and inclination angle of the adjustable glenoid trial in accordance with one or more features of the present disclosure;

[0043] FIG. 22A is a side perspective view of a surgical navigation instrument that can be used to correlate joint forces with implant position in accordance with one or more features of the present disclosure;

[0044] FIG. 22B is a side perspective view of a registration feature of an adjustable glenoid trial that can be recognized by a wireless pointer probe in accordance with one or more features of the present disclosure;

[0045] FIG. 23 illustrates a perspective view of a reverse shoulder assembly including an adjustable reverse gl enosphere and an adjustable reverse liner; and

[0046] FIG. 24 illustrates a perspective view of an anatomic shoulder assembly including an adjustable anatomic head and an adjustable glenoid trial.

[0047] The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict various examples of the disclosure, and therefore are not considered as limiting in scope. In the drawings, like numbering represents like elements.DETAILED DESCRIPTION

[0048] Various features or the like of adjustable arthroplasty component trial devices and methods will now be described more fully herein with reference to the accompanying drawings, in which one or more features of the adjustable arthroplasty component trialsand methods will be shown and described. It should be appreciated that the various features may be used independently of, or in combination, with each other. It will be appreciated that the adjustable arthroplasty component trial devices and methods as disclosed herein may be embodied in many different forms and may selectively include one or more concepts, features, or functions described herein. As such, the adjustable arthroplasty component trial devices and methods should not be construed as being limited to the specific examples set forth herein. Rather, these examples are provided so that this disclosure will convey certain features of the adjustable arthroplasty component trial devices and methods to those skilled in the art.

[0049] To limit or remove the uncertainty and imprecision associated with the "look and feel" approaches in intra-operative joint evaluation, the disclosed devices and methods allow surgeons to evaluate certain objective orthopedic performance parameters in realtime. In some examples, such parameters can include unrestricted load sensing generated by the muscle passive tension over the full articular surface accounting for extreme rotational movements that could impact the outer rim of the glenoid component. Furthermore, in some examples, the present devices and methods can be used to determine the uniformity of force distribution across the entire joint surface(s), which can provide a measure of deltoid pretension during surgery and how it may change during different arm positions that correlate with desired patient function after shoulder surgery. This feedback can inform the surgeon on the peak forces that may occur in the case of prosthetic impingement and the appropriate implant size and alignment strategy during surgery. In some examples, the present devices and methods can also accommodate the effect ofprocedural differences such as subscapularis repair, which is likely to change the joint tension and biomechanics throughout various ROM.

[0050] The on-board load sensing system can further be coordinated with precise- controlled automatic adjustability of the respective component trial to optimize the seating and orientation of the implant without the need for complex surgical navigation systems. Currently, for example, for an anatomic total shoulder arthroplasty, the position and orientation of a glenoid trial is fixed once the glenoid surface has been reamed and the peripheral holes are drilled to receive the pegs with the standard drilling template / guide. Using the present devices, systems, and methods, however, the appropriate size and / or configuration of the glenoid component can be assessed prior to drilling the peripheral holes. An adjustable trial could also apply a local controlled compression load to an area of the glenoid bone during the micro-adjustment step providing feedback to the surgeon on thresholds for bone quality and what the anticipated fixation of different types of implant sizes would be to assist in optimal glenoid implant selection.

[0051] In this regard, the present adjustable soft tissue balancing devices, systems, and methods provide in situ tension adjustment that is tailored to the desired total shoulder arthroplasty process.

[0052] Anatomic Total Shoulder Arthroplasty Adjustable Glenoid Trial

[0053] In accordance with one or more features of the present disclosure, an adjustable glenoid trial for an anatomic total shoulder arthroplasty will be disclosed. Referring to FIGS. 1A-2, in some examples, the adjustable glenoid trial, generally designated 100,includes a housing 110 that defines a body of the device and an outer skin 120 that defines a substantially elliptical-shaped glenoid surface that is configured to interface with the patient’s humeral head and / or an opposing implant element that is configured to replace the humeral head. The “pitch” and “roll” of the housing 110 can be adjusted to correspondingly change the position and / or orientation of the outer skin 120. In some examples, the housing 110 is composed of a metal such as aluminum, stainless steel, or titanium, whereas the outer skin 120 is composed of a polymer, such as 3M™ Polyimide Film Tape 5413. The housing 110 can further define an outer bone-facing surface 111 substantially opposing the outer skin 120. In some examples, a central post 112 can extend from the outer bone-facing surface 111 for locating and aligning the adjustable glenoid trial 100 with respect to a hole created by a reaming step of the glenoid replacement. In some examples, the central post 112 can have a diameter of about 2.5-2.8 mm and a length of about 15 mm. Further, in some examples, the outer bone-facing surface 111 also has four peripheral spikes 113 that provide temporary fixation during drill templating of the glenoid.

[0054] To adjust the shape and configuration of the outer skin 120, the adjustable glenoid trial 100 includes a plurality of actuators 130 coupled within the housing 110 and configured to be selectively and independently extendable or retractable with respect to the outer bone-facing surface 111. Such selective extension or retraction can be controlled to apply a linear force to the bone surface against which the adjustable glenoid trial 100 is positioned to thereby adjust the position and / or orientation of the housing 110 relative to the surface. In some examples, the projecting end of each of the leadscrews 131 is finished with a flat surface or “foot” that is configured to push against the glenoid surface. In theillustrated examples, the plurality of actuators 130 includes three micro- solenoid ratcheting leadscrews 131 located in distinct segments of the housing 110. This arrangement providing three points of contact can provide a stable tripod configuration for automatic adjustment. Those having ordinary skill in the art will recognize, however, that different configurations of the adjustable glenoid trial 100 can include more or fewer actuators 130. In some examples, a larger configuration of the adjustable glenoid trial 100 can accommodate four or more actuators 130 within the housing 110, with such a configuration providing additional degrees of freedom to manipulate the shape and / or configuration of the outer skin 120.

[0055] As shown in FIG. 1A, the leadscrews 131 can be threadedly coupled to the housing 110 through the outer bone-facing surface 111 such that rotation of the leadscrews131 results in a linear translation relative to the housing 110. In some examples, each of the leadscrews 131 is coupled to a ratchet pulley wheel 132 (e.g., having a diameter of about 8 mm), which is driven by a coil of wire 133 wound around the ratchet pulley wheel132 (e.g., having about 660 coil windings) and connected to pair of micro-solenoids 134 (e.g., having a diameter of about 3 mm). In some examples, the wire 133 is positioned sufficiently closely to the outer surface of the respective ratchet pulley wheel 132 such that tension applied to the wire 133 causes the wire to frictionally engage the outer surface of the ratchet pulley wheel 132 and drive rotation of the ratchet pulley wheel 132. Further, in some examples, this constriction of the wire 133 about the ratchet pulley wheel 132 holds the ratchet pulley wheel 132 stationary when the wire 133 is not being pulled in either direction. In some examples, the wire 133 can be reset after each ratchet event by exertinga gentle pull from the lesser-powered of the micro-solenoids 134 after the dominant one of the micro-solenoids 134 in the operation has been completely un-powered and is no longer pulling.

[0056] In this configuration, operation of a selected one of the micro-solenoids 134 applies a pull force in one direction to pull the wire 133 and drive rotation of the corresponding ratchet pulley wheel 132 and leadscrew 131 to adjust the position of the actuators 130 relative to the outer skin 120. Further, in some examples, by controlling the current in opposing micro-solenoids 134 connected to a common wire 133, the amount of tension applied to each end can be balanced to control the tightness of the wire 133. By applying one of micro-solenoids 134 to each end of the coil of wire 133, it is possible to ratchet the pulley wheel 132 around which the coil 133 is wound in either direction by setting the balance of current in each of the two micro-solenoids 134 to control which direction the ratchet pulley wheel 132 turns and hence the direction of linear displacement of the leadscrew 131. In some examples, each of the micro-solenoids 134 can include a compression spring so that, when the solenoid action on the core is completed, the core can be reset to its initial position by the compression spring.

[0057] In this configuration, each of the actuators 130 is capable of both forward and reverse motion (e.g., up to about + / -5 mm). In some examples, each of the leadscrews 131 has a pitch of between about 0.25 mm and 0.4 mm, and each ratchet pulley wheel 132 can have a wheel diameter of about 8 mm. In such an arrangement, the micro-solenoids 134 can be controlled such that 9-10 ratchet cycles can result in one full rotation of the ratchet pulley wheel 132, which can together result in 2.5 rotations per 1mm of linear travel. Aconfiguration of this kind can thus provide an adjustment range of about + / - 5 mm while supporting a linear force of about 50 N. This level of adjustment can enable optimization of the seating and fit of the glenoid implant in the glenoid vault after the initial reaming step. In some examples, given the elliptical shape of the glenoid trial, each of the miniature actuators 130 is positioned within the curved shape of the outer skin 120 such that the individual thrust provided by each of the actuators 130 allows a wide range of adjustments to the “pitch” and “roll” of the outer surface 120.

[0058] Referring to FIGS. 3A and 3B, the loads applied by the actuators 130 is sufficient to make adjustments to the trial position / orientation when the shoulder is in the neutral position. Specifically, FIG. 3A shows rotation characteristics derived from the dynamic assessments during maximum internal / external rotation, and FIG. 3B shows rotation characteristics derived from the dynamic assessments during forward elevation, where Fmax is the maximum load through the ROM, Fdweii is the average load in the dwell region, Favgis the average load through the entire ROM, Ftati is the average load in the tail region(s), RoMdweii is the width (in terms of rotation) of the dwell region, and RoMtotai is the width of the ROM (absolute min / max). For internal / external rotation maneuvers, the measured force has an approximately constant level near neutral rotation and often displays a steep increase in the glenohumeral load near the edges of the ROM.

[0059] When the tensioner is expanded, an increase in compressive load is typically observed with increased tightness during dynamic assessments. Given that the load is not constant through the ROM but constant near neutral rotation, a dwell region is introduced around the neutral position. Given the limited change in soft-tissue restraint in this zone,the ROM in the dwell region is linked to a functional zone whereby the joint can freely move without exerting excessive strain on the surrounding soft tissues. Depending on the tightness of the shoulder, this dwell region is bound by a tail region where the glenohumeral loads rapidly increase toward the end of the rotational range referred to as the optimal arc of motion free of bony impingement. The tail zones are indicative of joint stability and provides information about the intraoperative tightness of the joint based on the load magnitude and centroid data which are collected during the adjustment phase. In the absence of active muscle activity, this is attributed to the increasing tension in the soft tissues surrounding the joint and reflects the compressive stabilizing force imparted by this tension. The absence of a tail region could be attributed to a lack of soft tissue restraint indicating a potential risk for instability or joint dislocation. This has been observed for some loose shoulders with no tail region and a rather constant load through the joint.

[0060] In addition to providing in situ tension adjustment, the adjustable glenoid trial 100 can further be configured to provide an integrated load sensing system that provides real-time feedback in response to the adjustments to the seating and orientation of the implant. As illustrated in FIG. IB, in some examples, the adjustable glenoid trial 100 includes a metal cap 121 positioned beneath the outer skin 120 within the housing 110, the metal cap 121 defining one or more cantilever 122 to which a corresponding one or more load measuring sensor (e.g., strain gauges, thin film gauges) is bonded. In some specific examples, the sensors can include foil strain-gauges that are attached to the inner surface of the metal cap 121 to measure strain. The output from these strain gauges can be directly proportional to the linear force applied to the surface of the glenoid due to the action of thearticulating humeral surface. In some examples, the adjustable glenoid trial 100 is equipped with six load measuring sensors, each of which is decoupled from the associated cantilever 122. The cantilevers 122 form part of the pressure sensor assembly and are essentially miniature springs. In some examples, the cantilevers 122 are pre-formed on the metal cap 121 in an outward direction (i.e., toward the outer skin 120) as a default position.

[0061] When force is applied to the outer skin 120 of the adjustable glenoid trial 100, these cantilevers 122 can be pushed inward and will create strain on the inner surface of the outer skin 120, which can be measured by the associated load measuring sensor. In this arrangement, each load measuring sensor can be configured for measurement of an applied force. The forces measured by each load measuring sensor can represent the forces acting radially to the outer skin 120, which can be directly proportional to the linear force applied to the surface of the glenoid due to the action of the articulating humeral surface. As shown in FIGS. 4A and 4B, engagement of a humeral head, generally designated 150, with the adjustable glenoid trial 100 can be measured at the loading points associated with the one or more load measuring sensor such that any force applied to the outer skin 120 will be transmitted along the line of radius of the glenoid surface. In some examples, these elements of the adjustable glenoid trial 100 can be configured to exhibit a load tolerance that is sufficient to withstand the loads anticipated under adjustment (e.g., having a maximum load tolerance of about 50 N)

[0062] These load sensors can measure compressive loads unrestrictedly across the glenohumeral joint. In this instance, a patient’s unique shoulder biomechanics can be assessed in real-time in the operating room, providing the surgeon the opportunity to definethe optimum soft tissue tension from a pre-defined set of ideal target loads. This can occur through precise controlled adjustments during the trialing process when additional capsular releases or imbrication procedures may be required to improve ROM (e.g., active anterior elevation, active external rotation, and active internal rotation).

[0063] Referring again to the example shown in FIG. IB, the adjustable glenoid trial 100 can include further components within the housing 110 to support the operation of the device. In some examples, such components can include a printed circuit board 124 that can include an on-board processor and wireless chip supporting bi-directional communication of live data with and external tablet or mobile phone. In some examples, data communication can be provided via a Bluetooth lower energy protocol (e.g., BLE 4.2). The printed circuit board 124 can also support a means of data storage (e.g., RAM and ROM) that is configured to include instructions for a pre-determined set of actions for the actuators 130. In some examples, the adjustable glenoid trial 100 can further include a power source 125, such as a coin cell battery (e.g., 3V CR1025) and / or a charge reservoir capacitor configured to maintain the battery voltage during brief peak current. In some examples, the power source 125 can be configured to provide sufficient power to drive the actuators 130 for the duration of adjustment and testing (e.g., providing a minimum battery life of 40 minutes).

[0064] In some examples, the electronic components are hermetically sealed within the housing 110 (e.g., meeting the requirements of IPX4). To achieve this seal, as shown in FIG. 2, in some examples, a lip 114 is formed around a circumference of the housing 110 to which the metal cap 121 can be precisely fit, such as by laser welding. In addition, thesecomponents are sized to fit within even a smallest configuration of the housing 110 with sufficient headspace (e.g., about 4 mm) to ensure that the same components are compatible with all sizes of the adjustable glenoid trial 100 (e.g., XS, S, M, L).

[0065] Anatomic Total Shoulder Arthroplasty - Alternate Glenoid Trial

[0066] In accordance with one or more further features of the present disclosure, an alternative configuration for an adjustable glenoid trial will be disclosed. Referring to an example configuration shown in FIG. 5, an inflatable glenoid trial, generally designated 101, includes an inflatable balloon 140 having a shape of a glenoid trial, including a glenoid contact surface 141 and a humeral contact surface 142 that is configured to interface with the patient’s humeral head and / or an opposing implant element that is configured to replace the humeral head. One or both outer surface of the balloon 140 is laminated with sensors in a multiplexed array 143, with spatial densities designed to probe the complex nature the shoulder joint. In some examples, the sensor array 143 includes a plurality of individual pads 144 (e.g., 500 pm x 500 pm Au pads having a thickness of about 300 nm) interconnected by serpentine traces.

[0067] In one particular example, the balloon 140 has a shape that is designed to softly conform to the mating tissue surfaces, which allows for simultaneous, multimodal mapping of pressure, position, and contact forces. Integrating the pressure sensor array 143 onto the balloon 140 allows the system to be inserted through small openings with the balloon 140 in a deflated state. The balloon 140 may then be progressively expanded to an inflated state for spatiotemporal mapping of pressure generated once the inflated balloon 140 makescontact with the surface of the glenoid and humeral head surfaces as shown in FIG. 6. In some examples, expansion of the balloon 140 is achieved using an inflation port 145 provided in the balloon 140 that is in communication with a syringe pump or other pressure source. This approach avoids damaging any of the rotator cuff muscles, which typically occurs with a standard deltopectoral approach. In some examples, the balloon 140 is compatible with a subscapularis sparing windowed anterior technique, which preserves the subscapularis muscle. This configuration can thus reduce the risk of tearing, avoids splitting the deltoid muscle, thus improving the soft tissue balancing of the shoulder.

[0068] In some examples, the balloon 140 is composed of an inflatable body of low- density polymer, such as but not limited to a low-density polyethylene, and the sensor array 143 can comprise a highly sensitive and flexible strain sensor laminated onto the outside surface, such as is shown in FIG. 5. In some examples, the sensor array 143 includes a multifunctional collection of sensors, actuators, and associated electronics that are mounted onto elastic surfaces for multifunctional spatiotemporal mapping of the surfaces of the joint. In some examples, the elements / pads 144 of the sensor array 143 are mounted using stretchable interconnects made from gold (Au) (e.g., having a thickness of between about 100 to 300 nm, and a width of between about 15 to 50 pm) sandwiched in polyimide (PI) (e.g., having a thickness of between about 1 to 3.3 pm, and a width of between about 21 to 100 pm) create multiplexed arrays covering a desired area (e.g., about 1 cm x 1 cm). In this configuration, the sensor array 143 can accommodate biaxial stretching (e.g., of up to about 30%) without inducing fractures in the constituent materials. In some examples, microfabrication techniques adapted from those used in the semiconductor industry can beused to build multiple layers of sensing elements, actuators, and ultrathin polymers (e.g., having thicknesses of between about 1 to 3.3 pm) using silicon wafers as temporary substrates and transfer printing methods to deliver these layers to soft, elastomeric substrates.

[0069] In some examples, the inflatable glenoid trial 101 in this configuration can include a multiplexed data-acqui sition system that includes an application-specific integrated circuit (ASIC) chip (RHD2164, Intan Technologies) to amplify, digitize, and multiplex the signals, thereby reducing the total number of wires that connect to the testing instrument. Using the ASIC chip eliminates the requirement for flexible transistors at each unit cell and enables the system to leverage state-of-the-art microelectronic elements. Once the balloon 140 is expanded between the glenohumeral joint, the surface of the mating bones can be mapped and the contact forces determined. The balloon 140 can then be deflated and pulled out of the joint space.

[0070] Anatomic Total Shoulder Arthroplasty - Adjustable Humeral Head Trial

[0071] Alternatively, or in addition, an adjustable humeral head trial is also disclosed in accordance with one or more further features of the present disclosure. As shown in FIGS. 7A and 7B, a humeral head trial, generally designated 200, can include a housing 210 that is configured to interface with a base or stem that is mounted to the patient’s humerus. In some examples, the humeral head trial 200 further includes a substantially spherical surface 220 that is configured to interface with the patient’s glenoid and / or an opposing implant element that is configured to replace the glenoid. In some examples, thesurface 220 has a surface topography that is divided into a plurality of segments 221. The forward and reverse micro-adjustment mechanism described above with respect to the adjustable glenoid trial 100 can be adapted to the humeral head trial 200. In some examples, the adjustable humeral head trial 200 can be used in combination with the adjustable glenoid trial 100 or the inflatable glenoid trial 101 discussed above to provide additional modes of adjustability and load sensing to better allow surgeons to evaluate certain objective orthopedic performance parameters in real-time.

[0072] With continued reference to FIGS. 7A and 7B, the humeral head trial 200 can be adjusted in a manner similar to a small, powered version of a conventional ratcheting spanner tool. A plurality of actuators 230 correspondingly positioned beneath the plurality of segments 182 can be individually operated to achieve a specified displacement (e g., from about 0 mm to about 5 mm) in a direction extending away from the housing 210. In a configuration similar to that discussed above with respect to the adjustable glenoid trial 100, each of the actuators 230 can include a lead screw 231, a ratchet pulley wheel 232 coupled to the lead screw 231, and one or more micro-solenoid 234 connected to the ratchet pulley wheel 232 by a coil of wire 233. Referring to FIG. 8, each of the actuators 230 can be attached at one end to a cantilevered arm 222 within the humeral head trial 200 on which associated load sensors 226 can be mounted for measurement of force through the individual segments 221.

[0073] In some examples, each micro-solenoid 234 can achieve up to a pull force of 300 mN acting on the ratchet pulley wheel 232. For example, each micro-solenoid 234 pulsed with a nominal 10 mA current can achieve a pull force of 44 mN. If this pull forceis applied to the wire 233 around the ratchet pulley wheel 232, this force in turn creates a torque of 1.8 mNm. The integration of the ratchet pulley wheel 232 with the lead screw231 can thus deliver an upward linear thrust of 10 N on each of the segments 221, which is adequate to vertically deflect each of the segments 221 while the shoulder joint is offloaded in the neutral position. The pulsing current through the micro-solenoid 234 can be increased to 15 mA by virtue of the square law resulting in an upward thrust force of 25 N. Even higher coil currents can be used to deliver even greater force, if necessary assuming that the micro- solenoid 234 can tolerate the higher currents.

[0074] Each of the individual segments 221 is held by default at deflected position by virtue of the leadscrew 231 while the micro-solenoid 234 is unpowered. The linear pushing force can also be increased by either increasing the diameter of the ratchet pulley wheel232 to 10 mm or decreasing the diameter of the leadscrew 231 to 1 mm. The height of each of segments 221 can either be extended or depressed, although the torque required to reduce the height by the leadscrew 231 is much lower than the torque needed to increase the height. The height of the segments 221 can be reduced by pulling them in against a compressive linear force of up to 60 N. In some examples, a deflection rate of 1 mm per 25 s can be achieved by delivering a 2 mm pull distance per actuation of the micro-solenoid 234. In some examples, the wire 233 resolution translates to a step size on the deflection of 10 pm based upon 50 ratchet points located around the circumference of the ratchet pulley wheel 232, and so each rotation of the ratchet pulley wheel 232 translates to 0.5 mm deflection of the segment 221. In some examples, the humeral head trial 200 also contains a circuit board 224, which can include an on-board processor and wireless chip supporting bi-directional communication (e.g., using a BLE protocol), and a power source 225 (e.g., a CR1220 coin cell battery).

[0075] Anatomic Total Shoulder Arthroplasty - Alternate Humeral Head Trial

[0076] In accordance with one or more further features of the present disclosure, an alternative configuration for an adjustable humeral head trial will be disclosed. In place of the forward and reverse micro-adjustment mechanism described above with respect to the adjustable glenoid trial 100 and the adjustable humeral head trial 200, the height and radius of an alternative configuration for an adjustable humeral head trial, generally designated 201, can be achieved using a telescopic screw drive / bevel gear mechanism that is entirely housed within the adjustable humeral head trial 201. Again, in some examples, this configuration for the adjustable humeral head trial 201 can be used in combination with the adjustable glenoid trial 100 or the inflatable glenoid trial 101 discussed above to provide complex control of the shape and configuration of each element in the toral shoulder arthroplasty system, along with detailed load sensing capabilities, such as is shown in FIG. 24.

[0077] Referring to FIGS. 9A, 9B, and 10, an outer surface 220 of the adjustable humeral head trial 201 is configured to interface with the patient’s glenoid and / or an opposing implant element that is configured to replace the glenoid. In some examples, the outer surface 220 is defined by a plurality of mosaic outer surface segments 221 that are arranged about a central body portion 223 and that can be selectively extended outward with respect to the body portion 223 to adjust the height and / or radius of the surface 220with respect to a housing or stem, generally designated S, that is mounted to the patient’s humerus. In the example illustrated in FIG. 9A, a four-segment configuration having a ring of three segments 221 located around the perimeter and a fourth circular segment 221 located on top. Alternatively, in the example illustrated in FIG. 9B, sixteen (16) adjustable segments 221 are arranged to define the outer surface 220. In any configuration, in some examples, each of the adjustable segments 221 is approximately 0.5mm thick.

[0078] In some examples, the arrangement of segments 221 shown in FIG. 9B is based upon a segmented concept using a conventional Goldberg polyhedron design, which approximates towards a sphere using a mesh of pentagons and hexagons. A spherical arc surface can be added to each of these segments. Because the segments each have a fixed geometry, the “sphere” that results from selectively extending the segments 221 is comprised of a net of points of contact between the segments and the glenoid. It is assumed that this limited resolution on the “spherical net” is adequate to allow a judgement on size for best fit.

[0079] In any configuration of the outer surface segments 221, in some examples, adjustment of the height and / or radius of the outer surface 220 is performed by moving one of a first adjustment ring 240 that is configured to adjust an effective radius of the outer surface 220 or a second adjustment ring 248 that is configured to adjust a height of the outer surface 220. Referring to an example configuration shown in FIG. 10, the first adjustment ring 240 is rotatable about a central axis C and is threadedly coupled to a central actuator 241 that is movable up and down along the central axis C. In this arrangement, rotation of the first adjustment ring 240 drives the central actuator 241 up or down. Thecentral actuator 241 is coupled to a plurality of push-rods 245, with each of the push-rods245 being connected to one of the segments 221 that together define the outer surface 220. As a result, upward movement of the central actuator 241 correspondingly drives the plurality of push-rods 245 outward to expand the radius of the outer surface 220. In some examples, each of the plurality of push-rods 245 is positioned within a respective first recess 227 within the body portion 223 through which the push-rod 245 can be guided during extension or retraction of the segment 221 with respect to the body portion 223. (See, e g., FIG. 11B)

[0080] In some examples, the central actuator 241 comprises a conical surface 242 that forms the interface with push-rods 245. In this configuration, the angle of the conical surface 242 can be designed such that the amount of radial extension by the push-rods 245 is directly correlated to the linear travel of the central actuator 241. In this regard, in some examples, for every 1mm of vertical travel by the central actuator 241, the plurality of push-rods 245 each correspondingly travel exactly 1mm outward with respect to a radius of the outer surface 220.

[0081] In some examples, each of the segments is further connected to a stabilizing rod246 that is movable in parallel with a respective one of the push-rods 245 to prevent tilting or rotation of the associated segment 221 during extension away from or retraction towards the central body 223. An example configuration for a segment 221 connected to both a push-rod 245 and a stabilizing rod 246 is shown in FIG. 11 A. In some examples, each stabilizing rod 245 is positioned within a respective second recess 228 within the body portion 223 through which the stabilizing rod 246 can be guided during extension orretraction of the segment 221 with respect to the body portion 223. (See, e.g., FIG. 11B) The adjustable humeral head trial 201 can further include a retraction spring 247 coupled to each stabilizing rod 246 (e.g., arranged within a corresponding second recess 228) and arranged to bias the stabilizing rod 246 towards a retracted position. In this way, movement of the central actuator 241 away from the outer surface 220 results in automatic retraction of the plurality of segments 221 to decrease the radius of the outer surface 220.

[0082] Alternatively, or in addition, the second adjustment ring 248 is similarly rotatable about the central axis C and movable relative to the stem S mounted to the patient’s humerus to adjust a height of the outer surface 220. In some examples, the second adjustment ring 248 is threadedly coupled to a portion of the body portion 223 such that rotation of the second adjustment ring 248 causes a translation of the body portion 223 away from the stem S. In this way, the position of the adjustable humeral head trial 201 is moved away from the stem S, thereby effectively increasing the height of the trial component.

[0083] In some examples, actuation of either of the first adjustment ring 240 or the second adjustment ring 248 can be achieved by manipulating the position of the respective adjustment ring with a driver component 260. An outer edge of either or both of the first adjustment ring 240 or the second adjustment ring 248 can be configured as a bevel gear such that, when engaged with the driver component 260, rotation of the driver component 260 is translated into rotation of the respective adjustment ring about the central axis C. In some examples, the driver component 260 includes a flexible monobloc shaft that allows the operator to make incremental adjustments to the adjustable humeral head trial 201within the existing surgical site, even at oblique angles. In some particular examples, the driver component 260 is a laser-cut stainless steel reamer shaft. Using such a driver component 260, no additional stab incisions are required to access the indexing point on the adjustable trial.

[0084] In some examples, circuit board and load sensing element are located beneath the adjustable humeral head trial 201 (e.g., between the adjustable humeral head trial 201 and the stem S), enabling forces to be captured and wirelessly communicated with a connected device (e.g., a tablet). In some examples, a battery (e.g., a 40 mAh LiPo battery) is located inside the cavity component and electrically connected to the circuit board. In some examples, the circuit board is configured to log thread turns of the first adjustment ring 240 and / or the second adjustment ring 248 to control and pre-set the level of adjustments that correspond to existing implant sizes. In some examples, the circuit board can receive stored thread “turn” data from the scapula-side (e.g., from a corresponding adjustable glenoid trial) so the user has full over-sight over the entire adjustment schedule on both sides of the joint. In some examples, the circuit board can trigger audible and visual alerts to update the operator that the adjustment schedule has been completed successfully for each trial component.

[0085] In some examples, the internalized circuit board also consists of a 6+3-axis inertial measurement unit arrangement. This sensor can be used to measure joint angle (range) during standard positions (isolated glenohumeral) without soliciting the scapulo- thoracic joint (i.e., static activities of daily living positions, for example, multi -planar static movements such as abduction, external rotation, and forward flexion and functionalmovements (dynamic ADL positions)). The sensor can also be used to quantify movement quality during static and dynamic ADL’s (e.g., time lapsed domain features, number, timing of peaks, phase shifts, deceleration, average speed, period, amplitude, skewness).

[0086] Reverse total shoulder arthroplasty - Adjustable Humeral Liner Trial

[0087] Although the previous discussion of the adjustable glenoid trial 100, inflatable glenoid trail 101, adjustable humeral head trial 200, and adjustable humeral head trial 201 is presented in the context of an anatomic shoulder implant, those having ordinary skill in the art will recognize that the principles disclosed can similarly be applied to identifying the optimal configuration for components of a reverse shoulder implant, such as the effect of glenoid-sided lateralization on load magnitude given that above a certain value, since every millimeter of glenoid lateralization can have a significant impact on user function for a reverse shoulder prosthesis. In this regard, in accordance with one or more further features of the present disclosure, an adjustable humeral liner trial for a reverse total shoulder arthroplasty system will be disclosed. In some examples, an independent humeral liner height and version adjustment mechanism can be entirely housed within the smallest size humeral meta compaction stem cavity, referred generally as size 1 , and this mechanism can span the existing range of shoulder implant component sizes.

[0088] Referring to FIGS. 12 and 13, an adjustable humeral liner trial, generally designated 300, includes an articulating liner 310 that is configured to interface with an opposing gl enosphere implant element. The adjustable humeral liner trial 300 further includes an automatic adjustable version module 320 and a height adjustment module 330that are together operable to adjust he position and / or orientation of the articulating liner 310 with respect to a housing or stem, generally designated S, that is mounted to the patient’s humerus. The articulating liner 310 can be provided in a range of diameters comparable to the current humeral articular liners (e.g., 34 mm, 38 mm and 42 mm). If additional stability is required, the articulating liner 310 can also be configured to have a retentive design with the same thickness as a standard trial.

[0089] Regardless of the size and configuration of the articulating liner 310 selected, the version module 320 can be configured to adjust a version angle by rotating the articulating liner 310 with respect to a central core 312 that is mounted within the stem S. In this configuration, the central core 312 is substantially maintained in alignment with the stem S during adjustment of the articulating liner 310. As shown in FIGS. 14A and 14B, the version control module 320 includes a liner stem 322 that extends from the articulating liner 310 and is securely retained in a groove 323 that is arranged within the central core 312 at an angle relative to a central axis of the central core 312. In this arrangement, rotation of the articulating liner 310 is constrained to be about the axis of the groove 323, and thus rotation of the articulating liner 310 about this offset axis causes the articulating liner 310 to tilt relative to the central core 312, such as is shown in FIGS. 15A-15C. In some examples, the articulating liner 310 can be shaped or otherwise configured to include interference limits that prevent the version angle from being rotated beyond + / -3O0.

[0090] In some examples, the adjustable version module 320 includes a plurality of parallel ridges 324 (e.g., 7 ridges) spaced at regular intervals (e g., each corresponding to about 10° of rotation) to provide index positions for rotation. In such examples, the indexedposition can be held by a ball bearing 325 that clicks into the set of ridges 324 under force of a biasing element. In some examples, for instance, the ball bearing 325 is biased towards the ridges 324 by forced action of a spring held in tension by a grub screw. With this configuration, the version angle can be adjusted by turning the articulating liner 310 manually, and as it turns, the ball bearing 325 is pushed against the spring until it reaches a next ridge 324, at which point the bearing provides a tactile click indicating that it has reached the next index point. In some examples, the adjustable version module 320 can further include a version tensioner configured to create the necessary tension on the spring to provide tactile feedback. In some configurations, such a version screw tensioner can be pre-set in the factory to provide the desired spring tension to produce the tactile click.

[0091] In some examples, the adjustable version module 320 can be used to adjust a version angle to adapt to the resection of the humeral head. For instance, the humeral head is resected to a pre-determined version angle between -30 to +30 degrees. This predetermined version angle can be dialed into the adjustable humeral liner trial 300 using the “index click” as discussed above before inserting it into the joint space. The articulating liner 310 can then be inserted into the reamed canal of the humerus, and a baseline force measurement can be acquired. A corresponding glenosphere can be prepared and then inserted into the glenoid vault. In some examples, the height and diameter of the glenosphere can be adjusted automatically, if required, as discussed below. The surgeon has the option to change the version of the articulating liner 310, but such changes could require removing the trial components, resecting the humerus at another version angle, andre-setting the index click of the adjustable version module 320 to the corresponding setting (e.g. -20, -10, 0, 10, 20, 30 degrees).

[0092] In combination with the version angle adjustment, the height / thickness of the adjustable humeral liner trial 300 can be adjusted using the height adjustment module 330. In this regard, the height of the articulating liner 310 relative to an end of the stem S is adjustable over a range of values. In some examples, the height is adjustable from between about 0 mm to about 15 mm in increments of about 3 mm. In particular, in some examples, the liner height can be adjusted to provide either fine (e.g., about 0.4 mm) or coarse (e.g., about 3 mm) increments that align with the current humeral liner implant sizes (e.g., +0 mm, +3 mm, +6 mm, +9 mm, +12 mm, and +15 mm). To achieve this adjustment, the height adjustment module 330 includes an adjustable ring wheel 331 that is threadedly coupled to a central lead screw 313 extending from the central core 312. In addition, in some examples, the top surface of the adjustable ring wheel 331 interfaces with an underside of the articulating liner 310 in order to drive it upwards in height. In some examples, the central lead screw 313 has a diameter of about 4.5 mm capable of supporting a radial static load of 270N and an axial dynamic load of approximately 800N.

[0093] In this arrangement, rotation of the adjustable ring wheel 331 can correspondingly cause a translation of the lead screw 313 with respect to the stem S, resulting in a change of the position of the articulating liner 310 with respect to the stem S. In some examples, one complete turn of the lead screw 313 can be configured to correspond to a pitch of about 0.4 mm, and so a 3 mm height adjustment equates to 7.5 turns of the main lead screw.

[0094] In some examples, the height offset increments are logged and captured locally on an on-board micro-processor 334. In some examples, the micro-processor can be integrated in an electronics module 335 that is housed within the cavity of the stem component. In some examples, in addition to the micro-processor 334, the electronics module can include one or more of a communications processor (e.g., a Bluetooth 4.2 low energy module), an antenna, a 6-axis inertial measurement unit (IMU), and a battery (e.g., a 40 mAh battery). In some examples, the micro-processor 334 is configured to log thread turns of the adjustable ring wheel 331 to control and pre-set the level of adjustments that correspond to existing implant sizes. In some examples, the micro-processor 334 can receive stored thread “turn” data from the scapula-side (e.g., from a corresponding adjustable glenosphere trial) so the user has full over-sight over the entire adjustment schedule on both sides of the joint. In some examples, the micro-processor 334 can trigger audible and visual alerts to update the operator that the adjustment schedule has been completed successfully for each trial component.

[0095] As shown in FIG. 16, in some examples, the adjustable humeral liner trial can include two engagement ports 332 positioned on either side of the stem S (i.e., posterior and anterior) through which a driver element 360 can be engaged with the adjustable ring wheel 331 to account for left and rights sides procedures. This flexibility for accessing the adjustment mechanism allows the adjustable humeral liner trial to be used equally for a standard deltopectoral approach for a right shoulder (anterior side) and left shoulder(posterior side). This configuration thus negates the need for different components to bemade available for different sides, reducing inventory costs. An outer edge of adjustable ring wheel 331 can be configured as a bevel gear such that, when engaged with the driver element 360 (i.e., at either engagement port 332), rotation of the driver element 360 is translated into rotation of the adjustable ring wheel 331. In some examples, the driver element 360 can be a slow-speed electric screwdriver equipped with a high torque external motor. In some examples, similar to the driver component 260 discussed above with reference to the adjustable humeral head trial 201, the driver element 360 includes a flexible monobloc shaft (e.g., a laser-cut stainless steel reamer shaft) that allows the operator to make incremental adjustments to the adjustable humeral liner trial 300 within the existing surgical site, even at oblique angles. Using such a driver element 360, no additional stab incisions are required to access the indexing point on the adjustable trial.

[0096] In addition to adjusting the version angle and / or the height of the articulating liner 310, the adjustable humeral liner trial 300 can further include one or more loadmeasuring sensor in communication with the articulating liner 310, where each of the one or more load measuring sensor is configured to measure forces applied to the articulating liner 310. Referring to FIG. 17, in some examples, a load sensing element 340 is arranged between the adjustable ring wheel 331 and a body of the stem S. The load sensing element 340 is fitted below the mechanical drive system and adjustable liner can simplify the electrical connections to the micro-processor 334. In some examples, the load sensing element 340 is supported at its outer circumference, but a gap is created below an inner portion of the load sensing element 340, creating a cantilever effect that acts to concentrate the axal load exerted through the tensioning device. In this arrangement, the load sensingelement 340 can be sensitive enough to trace the center of a resultant applied load through the glenohumeral joint to optimize the load vectors.

[0097] In some examples, the load sensing element 340 is a disc made from either 15- 5PH or 17-4 stainless steel (e.g., about 0.381 mm thick) that is pre-polished in H900 condition to a surface finish better than O.Olum Ra that helps mitigate handling and distortion risks. The load sensing element 340 can be arranged such that any force applied to the articulating liner 310, whether axial or radial, will be transmitted to an inner circumference of the thin steel sensor plate, thereby creating a deflection across its diameter. In some examples, the load sensing element 340 includes an array (e.g., three) of sputtered sensor strain gauge bridges in a Wheatstone bridge configuration positioned with an angular separation of 120°.

[0098] Deflection of the load sensing element 340 will create measurable differential strain on the sensor array such that the vector angle of the force scalar may be determined as a measure of the relative magnitude of the sensor outputs. In some examples, the gap left underneath the load sensing element 340 is sized (e.g., pre-set at about 0.5mm) to keep strain levels on the gauged surface at around 1200 micro strain when loaded to full capacity, which would give a reasonable signal but also leave a bit of safety margin.

[0099] Reverse Total Shoulder Arthroplasty Glenosphere Trial

[0100] In accordance with one or more further features of the present disclosure, an adjustable glenosphere trial for a reverse total shoulder arthroplasty system will be disclosed. Referring to FIG. 18, an adjustable glenosphere trial, generally designated 400,can include an adjustable baseplate 410 having a housing 411 that defines a tapered mating surface 412 that matches a tapered base 416 of a glenosphere 415 that is configured to interface with an opposing humeral liner implant. In some examples, the adjustable glenosphere trial 400 can be used in combination with the adjustable humeral liner trial 300 discussed above to provide additional modes of adjustability and load sensing to better allow surgeons to evaluate certain objective orthopedic performance parameters in realtime.

[0101] In some examples, a plurality of actuators such as those previously shown and described with respect to the adjustable glenoid trial 100 and the adjustable humeral head trial 200 can be arranged within the adjustable baseplate 410 and can be configured to selectively change the position and / or orientation of an interfacing surface 413 of the adjustable baseplate 410, thereby causing the surface on the adjustable baseplate 410 to move against the corresponding surface of the glenosphere 415. In this way, the configuration of the adjustable baseplate 410 and corresponding arrangement of the glenosphere 415can be adjusted and tested to identify an optimal configuration. The surfaces of the glenosphere 415 and the adjustable baseplate 410 in the reverse trial can be configured to be congruent and matched in shape in order for the glenohumeral forces to be transmitted across the joint line.

[0102] Reverse Total Shoulder Arthroplasty - Alternate Glenosphere Trial

[0103] In accordance with one or more further features of the present disclosure, an alternative configuration for an adjustable glenosphere trial will be disclosed, in which atelescopic screw drive / bevel gear mechanism is provided for independent control of height and radius adjustments that is entirely housed with the spherical component of the glenosphere. In some examples, the mechanism is equipped with separate adjustment keys for glenosphere height and diameter, which can be accessed within joint space during a single trial reduction.

[0104] Referring to an example configuration shown in FIGS. 19A and 19B, the alternative configuration for an adjustable glenosphere trial, generally designated 401, exhibits a configuration that is similar to the configuration of the adjustable humeral head trial 201 discussed above. In this regard, an outer surface 420 of the adjustable glenosphere trial 401 that is configured to interface with an opposing humeral liner implant can be defined by a plurality of outer surface segments 421 that are arranged about a central body portion 423 and that can be selectively extended outward with respect to the body portion 423 to adjust the height and / or radius of the surface 420 with respect to a baseplate 410 that is mounted to the patient’s scapula. Again, in some examples, this configuration for the adjustable glenosphere trial 401 can be used in combination with the adjustable humeral liner trial 300 discussed above to provide complex control of the shape and configuration of each element in the toral shoulder arthroplasty system, along with detailed load sensing capabilities, such as is shown in FIG. 23.

[0105] In the illustrated example, four (4) adjustable segments 421 are arranged to define the outer surface 420. The four-segment configuration described herein is comprised of a ring of three segments located around the perimeter, and a fourth circular segment located on top. In some examples, each of the adjustable segments 421 is approximately0.5mm thick. Alternatively, in some examples, the arrangement of segments 421 is based upon a segmented concept using a conventional Goldberg polyhedron design, which approximates a sphere using a mesh of pentagons and hexagons. In some situations, a larger number of segments in the spherical net results in finer resolution, which provides a better judgement on size for best fit. A spherical arc surface can be added to each of these segments. In either configuration, because the segments each have a fixed geometry, the “sphere” that results from selectively extending the segments 421 is comprised of a net of points of contact between the segments and the humeral liner. It is assumed that this limited resolution on the “spherical net” is adequate to allow a judgement on size for best fit.

[0106] In some examples, adjustment of the height and / or radius of the outer surface 420 is performed by moving one of a first adjustment ring 440 that is configured to adjust a radius of the outer surface 420 or a second adjustment ring 448 that is configured to adjust a height of the outer surface 420. Referring to the example configuration shown in FIG. 19B, the first adjustment ring 440 is rotatable about a central axis C and is threadedly coupled to a central actuator 441 that is movable up and down along the central axis C. In this arrangement, rotation of the first adjustment ring 440 drives the central actuator 441 up or down. The central actuator 441 is coupled to a plurality of push-rods 445, with each of the push-rods 445 being connected to one of the segments 421 that together define the outer surface 420. As a result, upward movement of the central actuator 441 correspondingly drives the plurality of push-rods 445 outward to expand the radius of the outer surface 420.

[0107] In some examples, the central actuator 441 comprises a conical surface 442 that forms the interface with push-rods 445. In this configuration, the angle of the conical surface 442 can be designed such that the amount of radial extension by the push-rods 445 is directly correlated to the linear travel of the central actuator 441. In this regard, in some examples, for every 1mm of vertical travel by the central actuator 441, the plurality of push-rods 445 each correspondingly travel exactly 1mm outward with respect to a radius of the outer surface 420.

[0108] In some examples, the structure and connection of each of the segments is substantially similar to the configuration of the segments 221 of the adjustable humeral head trial 201 discussed above and shown in FIGS. 11A and 1 IB. In this regard, each of the segments 421 can be further connected to a stabilizing rod that is movable in parallel with a respective one of the push-rods 445 to prevent tilting or rotation of the associated segment 421 during extension away from or retraction towards the central body 423. In some examples, each of the push-rods 445 is positioned within a first recess, and each stabilizing rod is positioned within a respective second recess within the body portion 423. The adjustable glenosphere trial 401 can further include a retraction spring coupled to each stabilizing rod (e.g., arranged within a corresponding second recess) and arranged to bias the stabilizing rod towards a retracted position. In this way, movement of the central actuator 441 away from the outer surface 420 results in automatic retraction of the plurality of segments 421 to decrease the radius of the outer surface 420.

[0109] The second adjustment ring 448 is similarly rotatable about the central axis C and movable relative to the baseplate 410 mounted to the patient’ s scapula to adjust a heightof the outer surface 420. In some examples, the second adjustment ring 448 is threadedly coupled to a portion of the body portion 423 such that rotation of the second adjustment ring 448 causes a translation of the body portion 423 away from the baseplate 410. In this way, the position of the adjustable gl enosphere trial 401 is moved away from the baseplate 410, thereby effectively increasing the height of the trial component.

[0110] In some examples, actuation of either of the first adjustment ring 440 or the second adjustment ring 448 can be achieved by manipulating the position of the respective adjustment ring with a corresponding driver component 450. An outer edge of either or both of the first adjustment ring 440 or the second adjustment ring 448 can be configured as a bevel gear such that, when engaged with a respective driver component 450, rotation of the driver component 450 is translated into rotation of the respective adjustment ring about the central axis C. In some examples, similar to the driver component 260 discussed above with reference to the adjustable humeral head trial 201, the driver component 450 includes a flexible monobloc shaft (e.g., a laser-cut stainless steel reamer shaft) that allows the operator to make incremental adjustments to the adjustable glenosphere trial 401 within the existing surgical site, even at oblique angles. Using such a driver component 450, no additional stab incisions are required to access the indexing point on the adjustable trial.

[0111] In some examples, it can be necessary to adjust the first adjustment ring 440 before attempting to adjust the height using the second adjustment ring 448 to create space for the inner head component to move into. Adjusting the height will simultaneously reduce the radius for a given radius setting. In practical terms, if the height is increased by 1 mm but the radius remains unchanged, an increase in radius by 1 mm followed by an increasein height by 1 mm in a second step will simultaneously reduce the radius again by 1 mm. Conversely, if the radius and height are increased by 1 mm each then the radius is increased by 2 mm and then height is increased by 1 mm, and this second step will simultaneously reduce the radius back to an increase of only 1 mm.

[0112] In addition to the radius and depth adjustments, the adjustable glenosphere trial 401 can further provide an adjustable lateral offset. In some examples, the central actuator 441 is selectively coupled to the conical surface 442 at any of a variety of offset positions. In some examples, the conical surface 442 includes a slot or opening 443 in which a fastener 444 can be selectively inserted at any position along the length of the opening 443. Alternatively, the conical surface 442 can include a plurality of openings 443 into one of which the fastener 444 can be selectively inserted. In either configuration, the fastener 444 inserted into an opening or slot 443 can be engaged with an end of the central actuator 441 to secure the conical surface 442 to the central actuator 441 in a desired offset position, such as is shown in FIG. 19B. In some examples, a fixed 4 mm offset enables the outer surface 420 and the elements arranged therein (e.g., the central body 423 and push-rods 445) to be shifted by 4 mm immediately prior to surgery whilst maintaining the stem S and the central screw drive (i.e., the first adjustment ring 440, the central actuator 441, and the second adjustment ring 448) in the same original location.

[0113] With this combination of adjustment mechanisms, the adjustable glenosphere trial 401 can provide a desired fit with the patient’s anatomy. Currently, on the scapula side of the joint, conventional glenosphere trials are available in 34 mm, 38 mm, or 42 mm diameters. The 34 mm glenospheres are also available in +1 mm lateralization. The 38 mmand 42 mm glenospheres are available in concentric, 0 mm lateralized; concentric, 3 mm lateralized; eccentric, 0 mm lateralized; and eccentric, 3 mm lateralized (42 mm diameter only). The same functionality of this array of trials can be provided using a single adjustable glenosphere trial 401 having a 4 mm range of radius adjustment, a 4 mm range of height adjustment, and a 4 mm offset selection (either zero or 4mm).

[0114] Methods For Soft Tissue Balancing Using Adjustable Trial Components

[0115] Regardless of the particular configuration of the adjustable trial devices used, a method for trial adjustment, generally designated 500, is further provided in accordance with one or more features of the present disclosure. The current approach for TSA component trialing is constrained and does not account for the tension in the surrounding soft tissue structures. For instance, with respect to trialing of an anatomic glenoid component, once the central pin hole and peripheral peg holes have been created, the version (pitch) and inclination (roll) angle of the glenoid trial cannot be subsequently adjusted. In contrast, the adjustable glenoid trial 100 associated with the examples shown and described with reference to FIGS. 1-2A is configured to make fine adjustments to both the version and inclination angle of the glenoid component. Although the method 500 is described with reference to the adjustable glenoid trial 100, those having ordinary skill in the art will recognize that the present methods can also correspondingly be implemented for the anatomic humeral head trials shown and described with reference to FIGS. 7A-1 IB, for the reverse humeral liner trial shown and described with reference to FIGS. 12-17, and for the reverse glenosphere trials shown and described with reference to FIGS. 18-19B.

[0116] Referring to FIG. 20, the method 500 can include a target setting step 501 in which the desired load and ROM curves are defined. In an initialization step 502, the respective adjustable trial component can be switched on and arranged in a fully collapsed position (e.g., with all of the actuators / push-rods at a minimum height). In a surface preparation step 503, the bone can be prepared to accept the adjustable trial component. With reference to the adjustable glenoid trial 100 described herein, for example, this preparation can include creating a central hole for locating a guide pin for the reaming step to remove the articular cartilage. The bone can further be reamed until proper concavity has been achieved congruent to the backside radius of the adjustable glenoid trial 100. Subsequently, the reamer and guide pin can be removed. In a trial implantation step 504, the adjustable trial component can be temporarily attached to the prepared bone surface. Referring again to the adjustable glenoid trial 100, for example, the central post 112 of the adjustable glenoid trial 100 is inserted into the central guide pin hole, which provides one point of provisional fixation. In some examples, the adjustable glenoid trial 100 can further include a plurality of peripheral spikes 113 that can establish a minimum clearance between the outer bone-contacting surface 111 of the adjustable glenoid trial 100 and the glenoid surface. In a trial installation step 505, initial adjustment of the adjustable trial component can be performed to set a baseline version and / or inclination.

[0117] The adjustable trial component can then be used to identify the optimum seating for the trial component using the wireless micro-adjustment mechanism and force / pressure feedback achieved during passive ROM to determine the optimum component configuration. For the adjustable glenoid trial 100, for example, adjustments can thus bemade to the version angle (See, e.g., FIG. 21A) and inclination angle (See, e.g., FIG. 21B). In some examples, various maneuvers are performed, which aim to cover a wide range of motion and represent the functional space of the shoulder while assessing the joint tightness. Specifically, in some examples, a load measurement step 506 can be performed in which the joint is manually taken through a known range of motion exercise. As discussed above, in some examples, one or more load measuring sensor can quantify the linear force applied across the glenohumeral joint. A target comparison step 507 can involve analyzing whether the load and ROM curves observed during the load measurement step 506 are within the defined ranges identified in the target setting step 501. If the measured parameters do not correspond to the target values, a sizing comparison step 508 can involve analyzing whether the measured curves are underloading the joint. If the joint is not underloaded, a hardware exchange step 510 can involve removing the appropriate hardware and returning to the surface preparation step 503 as needed.

[0118] If the joint is underloaded, however, a trial adjustment step 509 can be performed in which the adjustable trial component is operated to make the appropriate adjustments to the trial to correspond more closely to the defined curves. As discussed above with respect to the adjustable glenoid trial 100, in some examples, this adjustment can involve adjusting the height of one or more of the plurality of actuators 130 of the adjustable glenoid trial 100 relative to the outer bone-facing surface 111 to correspondingly push against the surface of the bone, changing the position / orientation of the adjustable glenoid trial 100 between the bone and the humeral head 150. In some examples, the central post 112 is pivotably connected to the adjustable glenoid trial 100 such that the positionand / or orientation of the adjustable glenoid trial 100 can be adjusted relative to a central point of fixation without applying undue torsional loads to the central post 112. The load measurement step 506, target comparison step 507, and trial adjustment step 509 can be repeated until the load and ROM curves are within the target ranges. In this way, the adjustable trial component can be used to identify an optimal arrangement of the trial component, which can be used to guide the placement of a permanent hardware component.

[0119] In some examples, the adjustable trial components can be optionally paired with a surgical navigation system in order to link glenohumeral forces with implant position. Referring to an example configuration illustrated in FIGS. 22A-22B using the adjustable glenoid trial 100, the adjustable glenoid trial 100 described herein can be optionally designed to synchronize with a surgical navigation instrument, generally designated 160. In some examples, the surgical navigation instrument 160 includes of a rounded tip 162 for standard registration, and a set of active infrared LED markers, a lithium battery (e.g., CR2 battery), a transceiver unit, and a trigger button. Three degrees-of-freedom position of the adjustable glenoid trial 100 can be achieved by introducing a divot 115 positioned in a side of the adjustable glenoid trial 100, such as is shown in FIG. 22B. Those having ordinary skill in the art will recognize, however, that the use of a surgical navigation instrument 160 can likewise be correspondingly paired with the anatomic humeral head trials shown and described with reference to FIGS. 7A-1 IB, with the reverse humeral liner trial shown and described with reference to FIGS. 12-17, and with the reverse glenosphere trials shown and described with reference to FIGS. 18-19B

[0120] In any configuration, the surgical navigation instrument 160 can include wireless pointers to enable joint forces to be correlated with implant position. Six degrees- of-freedom position and orientation of the trial can be achieved by matching the surface geometry between the associated implant trial component and a probe paddle 170 whilst aligning a set of indentations between the two mating components. Surface registration of the trial involves collecting points from the trial divot 115 using the pointer probe or the probe paddle 170, which contains 3 divots that precisely matches the divots located in the upper surface of the trial. After registration, the navigation system reports a fiducial registration error (FRE).

[0121] During surgical navigation, a marker can be attached to either the acromion or coracoid process and proximal humerus. These anatomical landmarks are registered and digitized with the surgical navigation instrument 160, which is optically tracked by an IR camera relative to a digital reference frame so the coordinates of the points in patient space can be determined and transformed to image space. A point probe is typically used for checking and confirming, during surgery, the reliability and accuracy of a computer assisted navigation procedure that is performed with either optically tracked passive, semiactive, or active robotic tools.

[0122] While the present disclosure refers to certain examples, numerous modifications, alterations, and changes to the described examples are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claim(s). Accordingly, it is intended that the present disclosure not be limited to the described examples, but that it has the full scope defined by the language of the followingclaims, and equivalents thereof. The discussion of any example is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples. In other words, while illustrative examples of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.

[0123] The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more examples or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of the certain examples or configurations of the disclosure may be combined in alternate examples, or configurations. Any example or feature of any section, portion, or any other component shown or particularly described in relation to various examples of similar sections, portions, or components herein may be interchangeably applied to any other similar example or feature shown or described herein. Additionally, components with the same name may be the same or different, and one of ordinary skill in the art would understand each component could be modified in a similar fashion or substituted to perform the same function.

[0124] Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate example of the present disclosure.

[0125] As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to “one example” of the present disclosure are not intended to be interpreted as excluding the existence of additional examples that also incorporate the recited features.

[0126] The phrases “at least one,” “one or more,” and “and / or,” as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. The terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader’s understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., engaged, attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative to movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. All rotational references describe relative movement between the various elements. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative to sizes reflected in the drawings attached hereto may vary.

Claims

CLAIMSWe claim:

1. An adjustable trial device for use in determining an optimal configuration for a component of a total shoulder arthroplasty implant, the device comprising: a housing defining an outer bone-facing surface; an implant interface surface; and a plurality of actuators positioned within the housing, wherein the plurality of actuators is operable to adjust a position or orientation of the implant interface surface.

2. The adjustable trial device of claim 1, wherein each of the plurality of actuators comprises: a pulley wheel coupled to the leadscrew; and one or more solenoids coupled to the pulley wheel; wherein actuation of the one or more solenoids rotate the pulley wheel.

3. The adjustable trial device of claim 2, wherein the one or more solenoid is coupled to the pulley wheel by a coil of wire that is wound around the ratchet pulley wheel; and wherein actuation of the one or more solenoids rotates the pulley wheel by applying a pull force to the coil of wire.

4. The adjustable trial device of claim 1, wherein the plurality of actuators comprises: a primary actuator that is linearly movable within the housing; anda plurality of push-rods coupled to the primary actuator; wherein the implant interface surface comprises a plurality of surface segments that together define the implant interface surface; wherein each of the plurality of push-rods is connected to one of the plurality of surface segments; and wherein movement of the primary actuator causes a corresponding movement of the plurality of push-rods to adjust a position of the plurality of surface segments of the implant interface surface.

5. The adjustable glenoid trial of claim 1, comprising one or more load measuring sensor in communication with the implant interface surface, wherein each of the one or more load measuring sensor is configured to measure forces applied to the implant interface surface.

6. The adjustable trial device of claim 1, wherein the device comprises an adjustable glenoid trial device for an anatomic total shoulder arthroplasty system comprising a central post extending from the outer bone-facing surface, the central post being configured to interface with a hole in a surface of a glenoid; wherein the plurality of actuators each comprise a leadscrew that is selectively extendible through the outer bone-facing surface to adjust a position of the housing with respect to the surface of the glenoid.

7. The adjustable trial device of claim 6, wherein the implant interface surface comprise an outer skin attached to the housing substantially opposing the outer bone-facing surface, wherein the outer skin defines a substantially elliptical-shaped glenoid surface.

8. The adjustable trial device of claim 1, wherein the device comprises an adjustable humeral head trial device for an anatomic total shoulder arthroplasty system; wherein the implant interface surface comprises a substantially spherical surface that is divided into a plurality of surface segments.

9. The adjustable trial device of claim 1, wherein the device comprises an adjustable humeral liner trial device for a reverse total shoulder arthroplasty system; wherein the implant interface surface comprises an articulating liner; and wherein the plurality of actuators comprises: an adjustable version module that is configured to adjust a version angle by rotating the articulating liner with respect to the housing; and a height adjustment module configured to adjust a height of the articulating liner with respect to the housing.

10. The adjustable trial device of claim 1, wherein the device comprises an adjustable glenosphere trial device for a reverse total shoulder arthroplasty system; wherein the implant interface surface comprises a substantially spherical surface that is divided into a plurality of surface segments.

11. A method for determining an optimal configuration for a component of a total shoulder arthroplasty implant, the method comprising: positioning an adjustable trial device against a prepared bone surface, wherein the adjustable trial device comprises a housing defining an outer bone-facing surface and an implant interface surface; and adjusting a position or orientation of the implant interface surface with respect to the bone surface by actuating one or more of a plurality of actuators positioned within the housing.

12. The method of claim 11, wherein actuating the one or more of the plurality of actuators comprises selectively adjusting a position of a leadscrew of each of the plurality of actuators relative to the outer bone-facing surface.

13. The method of claim 11, wherein each of the plurality of actuators comprises: a pulley wheel coupled to the leadscrew; and one or more solenoid coupled to the pulley wheel; wherein actuating a plurality of actuators comprises actuating the one or more solenoid to rotate the pulley wheel.

14. The method of claim 13, wherein the one or more solenoid is coupled to the pulley wheel by a coil of wire that is wound around the ratchet pulley wheel; andwherein actuating the one or more solenoids comprises applying a pull force to the coil of wire.

15. The method of claim 11, wherein actuating the one or more of the plurality of actuators comprises moving a primary actuator within the housing to cause corresponding movement of each of a plurality of push-rods coupled to the primary actuator; wherein the implant interface surface comprises a plurality of surface segments that together define the implant interface surface; wherein each of the plurality of push-rods is connected to one of the plurality of surface segments; and wherein movement of the plurality of push-rods adjust a position of the plurality of surface segments of the implant interface surface.

16. The method of claim 11, wherein one or more load measuring sensor is positioned within the housing in communication with the implant interface surface; and wherein the method further comprises measuring forces applied to the implant interface surface using the one or more load measuring sensor.

17. The method of claim 11, wherein the adjustable trial device comprises an adjustable glenoid trial device for an anatomic total shoulder arthroplasty system comprising a central post extending from the outer bone-facing surface, the central post being configured to interface with a hole in a surface of a glenoid;wherein the plurality of actuators each comprise a leadscrew; and wherein adjusting a position or orientation of the implant interface surface comprises selectively extending one or more of the leadscrews through the outer bonefacing surface to adjust a position of the housing with respect to the prepared bone surface.

18. The method of claim 17, wherein the implant interface surface comprise an outer skin attached to the housing substantially opposing the outer bone-facing surface, wherein the outer skin defines a substantially elliptical-shaped glenoid surface; and wherein positioning the adjustable glenoid trial comprises orienting an outer skin attached to the housing substantially opposing the outer bone-facing surface, wherein the outer skin defines a substantially elliptical-shaped glenoid surface.

19. The method of claim 11, wherein the adjustable trial device comprises an adjustable humeral head trial device for an anatomic total shoulder arthroplasty system; wherein the implant interface surface comprises a substantially spherical surface that is divided into a plurality of surface segments; and wherein adjusting a position or orientation of the implant interface surface comprises adjusting a position of each of the plurality of surface segments with respect to the housing.

20. The method of claim 11, wherein the adjustable trial device comprises an adjustable humeral liner trial device for a reverse total shoulder arthroplasty system;wherein the implant interface surface comprises an articulating liner; and wherein adjusting a position or orientation of the implant interface surface comprises: adjusting a version angle by rotating the articulating liner with respect to the housing; and adjusting a height of the articulating liner with respect to the housing.

21. The method of claim 11 , wherein the adjustable trial device comprises an adj ustable glenosphere trial device for a reverse total shoulder arthroplasty system; wherein the implant interface surface comprises a substantially spherical surface that is divided into a plurality of surface segments; and wherein adjusting a position or orientation of the implant interface surface comprises adjusting a position of each of the plurality of surface segments with respect to the housing.

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