Rod reduction device feedback system

Abstract

Various embodiments include rod reduction instruments, spinal fixation monitoring systems, and associated methods. Certain embodiments include a rod reduction instrument adapted for use with a spinal fixation system, including a sensor configured to detect loads exerted on the spinal rod by the rod reducer, along with a reduction feedback system that provides an indicator of the loads exerted on the spinal rod by the rod reducer.

Description

Technical Field

[0001] Priority Claim This application claims the benefit of U.S. Provisional Application No. 63 / 239,148, filed Aug. 31, 2021.

[0002] The present disclosure generally relates to medical devices. More particularly, the present disclosure relates to the field of spinal surgery and spinal fixation devices.

Background Art

[0003] Spinal fixation constructs are utilized to provide stability to the spine. In most cases, the fixation construct is used as an aid to a fusion surgery where adjacent vertebrae are prepared to facilitate bone growth between them. Since movement between vertebrae tends to inhibit bone growth, the fixation construct is employed to prevent movement so that bone can grow to achieve a solid fixation. If the position of one or more vertebrae must be adjusted to restore a more natural alignment of the spinal column, the fixation construct also functions to maintain the new alignment until fusion is achieved.

[0004] Various forms of fixation structures are known in the art, of which rod-based fixation structures are among the most common. Typically, a rod-based structure comprises multiple anchors, which are coupled to parts of two or more vertebrae (e.g., posterior elements) and then connected by fixation rods. Each anchor further comprises a rod housing into which the fixation rod is captured and locked. The rod housing may be fixed to the anchor portion and coupled pivotably or rotatably, and generally comprises a pair of upright arms separated by rod channels. When constructing a fixation structure, the surgeon must align and seat the rods within the rod channels of each anchor, a process commonly referred to as "reduction." Reduction can be challenging, especially when one or more of the vertebrae to be connected are not aligned with the others, and the reduction distance and force requirements can vary considerably from anchor to anchor. Conventional reduction procedures rely heavily on the surgeon's (or operator's) expertise in determining the load applied to the spinal rods by each rod reducer. In multilevel fixation procedures involving multiple vertebrae, it can be particularly difficult for the surgeon to determine which rod reducer(s) are properly loaded while engaged with the spinal rods. [Overview of the project]

[0005] The above and other needs are addressed by embodiments of rod reduction devices, spinal fixation monitoring systems, and related methods described herein. All examples and features described below can be combined in any technically possible way.

[0006] Various embodiments include rod reduction devices, spinal fixation monitoring systems, and associated methods. Certain embodiments include a rod reduction device adapted for use with a spinal fixation system, and include a sensor configured to detect the load applied to the spinal rods by the rod reduction device, together with a reduction feedback system that provides an indicator of the load applied to the spinal rods by the rod reduction device.

[0007] In a particular embodiment, a rod reduction device adapted for use with a spinal fixation system comprises: a rod reduction device having a proximal end and a distal end, the distal end of which is configured to engage with a spinal rod to seat the spinal rod in a pedicle screw receiver; a sensor configured to detect the load applied to the spinal rod by the rod reduction device while seating the spinal rod in the pedicle screw receiver; and a reduction feedback system coupled to the sensor, the reduction feedback system configured to receive load data from the sensor indicating the load applied to the spinal rod by the rod reduction device, and to provide an indicator of load data detectable by an operator of the rod reduction device.

[0008] In additional specific embodiments, the method includes providing feedback to an operator during a spinal fixation procedure, the spinal fixation procedure including engaging a spinal rod with a rod reducer to seat the spinal rod within a pedicle screw receiver. The method may further include receiving load data from a sensor indicating the load applied to the spinal rod by the rod reducer while seating the spinal rod within the pedicle screw receiver, and providing an indicator of load data detectable by an operator during the spinal fixation procedure.

[0009] In a further specific embodiment, a spinal fixation monitoring system for use in a spinal fixation procedure includes a plurality of rod reduction devices adapted for use with a spinal fixation system, each of which is a rod reduction device having a proximal and distal end, the distal end of which is configured to engage with a spinal rod to seat a spinal rod in a corresponding pedicle screw receiver; a sensor configured to detect the load applied to a portion of the spinal rod by the rod reduction device while seating the spinal rod in the pedicle screw receiver; and a reduction feedback system coupled to each sensor of the rod reduction device, which is configured to receive load data indicating the load applied to a portion of the spinal rod by each rod reduction device from a corresponding one of the sensors and to provide an indicator of the load data relating to at least one of the rod reduction devices in the plurality of rod reduction devices, the indicator being detectable by an operator of the plurality of rod reduction devices.

[0010] In other specific embodiments, the spinal fixation system includes a first bone anchor comprising a first pedicle screw and receiver; a rod configured to seat within the receiver of the first bone anchor; an instrument configured to be coupled to the first bone anchor; and a sensor coupled to the instrument and configured to determine data relating to at least one of the first bone anchor, the rod, or the instrument.

[0011] The embodiments may include one of the following features, or any combination thereof.

[0012] In certain cases, the rod reduction device further comprises a housing mounted on the proximal end of the rod reducer, and the reduction feedback system is arranged within the housing.

[0013] In some cases, the housing may be a) modular and / or disposable, b) mounted on an existing nut and disposable, or c) mounted on any part of a rod restorer.

[0014] In certain embodiments, the repositioning feedback system includes a processor and memory, the memory which, when executed, stores instructions that the processor uses to compare load data with a load threshold of a rod repositioner and provide an indicator of whether the load data meets or does not meet the load threshold of the rod repositioner.

[0015] In certain embodiments, the load data at least partially represents the amount of torque applied to the locking screw while tightening the locking screw within the pedicle screw receiver and the compressive force applied to the rod reducer, and the indicator of whether the load data meets or does not meet the load threshold includes an indicator of the amount by which the compressive force applied to the spinal rod should be modified to meet the load threshold of the rod reducer, and the load threshold is at least partially based on a model that correlates clinical data representing patient-specific bone quality with screw extraction.

[0016] In certain cases, the load threshold defines the maximum permissible load applied to the spinal rod by the rod reducer while seating the spinal rod within the pedicle screw receiver, and the maximum permissible load is a) approximately 50 pounds (222N) ~approximately £250 (1112N) b) Approximately 25 pounds (111N) ~approximately £150 (667N) , or c) about 25 pounds (111N) ~approximately £75 (334N) That is the case.

[0017] In some embodiments, the processor is further configured to compare load data with additional load data detected by an additional set of sensors coupled to an additional rod corrector, and to provide an indicator of the relative load of the rod corrector compared to at least one of the additional rod correctors in the set.

[0018] In certain embodiments, the relative load indicator shows whether a rod restorer is more, less, or equally loaded than additional rod restorers in the set.

[0019] In some cases, the relative load indicator always includes the indicator of the smallest load rod restorer in the set.

[0020] In a particular aspect, the processor is configured to update the relative load indicator over time as the load data for at least one of the rod restorers or additional rod restorers in the set is updated.

[0021] In certain cases, the restoration device is configured for use in a multi-level restoration procedure such that the indicator of the load data includes the relative load indicator of the rod restorer compared to the set of additional rod restorers engaged with the spinal rod.

[0022] In a particular embodiment, the spinal fixation system includes a set of rod restoration devices having a set of rod restorers engaged with the spinal rod, and the restoration feedback system is communicatively coupled to each of the rod restoration devices and configured to receive load data indicating the load exerted on the spinal rod by each rod restorer.

[0023] In some aspects, the set of rod restorers includes a total of up to 20 rod restorers arranged in 10 subsets on each side of the patient's spine.

[0024] In certain cases, the restoration feedback system is further configured to provide an indicator of the restoration order for the set of rod restoration devices based on the received load data.

[0025] In a particular aspect, the indicator of the restoration order includes instructions for multi-level restoration of the set of rod restoration devices.

[0026] In some embodiments, the restoration feedback system compares load data from two or more of the rod restoration instruments in the set to a set of load thresholds and provides an indicator that prioritizes an increased load on a particular rod restoration instrument over at least one additional rod restoration instrument based on whether the load data from the two or more rod restoration instruments meets the set of load thresholds.

[0027] In certain cases, the set of load thresholds includes absolute load thresholds for each of two or more rod restoration instruments.

[0028] In a particular aspect, the absolute load threshold varies based on at least one of a) the location of a given rod restoration instrument along the patient's spine, b) the patient's anatomical structure, or c) the patient's bone mass.

[0029] In some embodiments, the set of load thresholds includes relative load thresholds for each of two or more rod restoration instruments.

[0030] In a particular aspect, the restoration feedback system includes an electronics compartment physically coupled to the rod restorer, and the electronics compartment has at least one of a visual display system or a tactile display system for providing an indicator of load data proximate to the rod restorer.

[0031] In a particular embodiment, the tactile display system includes at least one vibrating tactile actuator.

[0032] In some cases, the restoration feedback system further includes a controller coupled to the electronics compartment and to a set of additional electronics compartments on a set of additional rod restoration instruments within the spinal fixation system, and the controller is configured to communicate with the electronics compartment and the set of additional electronics compartments via a wireless or wired connection.

[0033] In a particular aspect, the wired connection includes an optical fiber connection.

[0034] In certain cases, the visual display system includes a set of lights configured to illuminate in at least two different patterns to indicate distinctions between load data, or a display configured to provide at least two different visual indicators of load data.

[0035] In some embodiments, the display includes a liquid crystal display (LCD).

[0036] In certain embodiments, the rod reduction device further includes a power supply housed within an electronics compartment and coupled with a visual or tactile display system.

[0037] In a particular embodiment, the sensor is located between the proximal and distal ends of the rod retractor.

[0038] In some cases, the rod retractor may have a multi-section shaft, and the sensor may be mounted axially between different sections of the multi-section shaft.

[0039] In certain embodiments, the sensor is coupled to the proximal end of the rod reducer.

[0040] In certain embodiments, the sensor is housed within a housing together with at least a portion of a correction feedback system.

[0041] In some cases, the sensor includes at least one of a strain gauge, a pressure-sensitive film, or a capacitive sensor.

[0042] In certain embodiments, the rod reduction device further comprises a guide assembly configured to be coupled with a pedicle screw receiver and to receive the rod reduction device therein.

[0043] In certain cases, the rod retractor is configured to fully seat the spinal rod within the pedicle screw receiver, allowing the spinal rod to be fixed in the pedicle screw receiver.

[0044] In some embodiments, the reduction feedback system is provided in the rod reducer or in an output device separate from the rod reducer.

[0045] In certain embodiments, the output device includes at least one of the following: a) a user interface, b) a display, c) an audio system, or d) a surgical interface.

[0046] In certain cases, the spinal fixation system is configured such that the rod reducer is located within a guide assembly that connects to the pedicle screw receiver, and the rod reducer is configured to fully seat the spinal rod within the pedicle screw receiver, thereby enabling the spinal rod to be fixed to the pedicle screw receiver.

[0047] In certain embodiments, the reduction feedback system comprises a housing mounted on the proximal end of each rod reducer to provide an indicator of load data adjacent to each rod reducer.

[0048] In certain cases, a sensor coupled to an instrument and configured to determine data relating to at least one of a first bone anchor, rod, or instrument determines data including load data.

[0049] In some embodiments, the instrument configured to connect to a first bone anchor is a reduction instrument configured to seat a rod within a receiver, and the load data includes the load applied to the rod by the reduction instrument while seating the rod within the receiver of the first bone anchor.

[0050] In certain embodiments, a sensor coupled to the device is configured to determine data relating to at least one of a first bone anchor, rod, or device, including data including tensile load between the rod and the bone anchor when the rod is at least partially seated within the bone anchor.

[0051] In some cases, a sensor coupled to the device is configured to determine data relating to at least one of a first bone anchor, a rod, or the device, and to determine data including torsional force data. In certain embodiments, the device is a driver configured to tighten a locking screw in a receiver and lock the rod against a bone anchor, and the torsional force data includes the torsional force on the locking screw while tightening the locking screw in the receiver. In additional specific embodiments, the device is a driver configured to seat the rod in a receiver and lock the rod against a bone anchor by tightening a locking screw in the receiver, and the torsional force data includes the torsional force on the locking screw while tightening the locking screw in the receiver.

[0052] In certain cases, the device configured to connect to a first bone anchor comprises a rod reduction device configured to seat a rod within a receiver, and a driver inserted through the rod reduction device and configured to deliver and tighten a locking screw within the receiver, thereby locking the rod against the bone anchor. In some of these embodiments, the data includes at least one of the loads exerted on the rod by the reduction device while seating the rod within the receiver of the first bone anchor, or the tensile load between the rod and the bone anchor when the rod is at least partially seated within the bone anchor. In some additional embodiments, the data includes the torsional force on the locking screw while tightening the locking screw within the receiver.

[0053] In certain embodiments, the spinal immobilization system further includes a navigation system that is communicatively coupled to the device and configured to detect the device's position. In some of these cases, the navigation system is configured to determine the distance traveled by the device when the device changes position, and the navigation system communicates the distance to a processor.

[0054] Two or more features described in this disclosure, including those described in this summary section, can be combined to form embodiments not specifically described herein.

[0055] The above provides a simplified overview to offer a basic understanding of some aspects of the claimed subject matter. This overview is not a comprehensive overview. It is not intended to identify major or significant elements or to describe the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed explanations that will follow.

[0056] Details of one or more embodiments are described in the accompanying drawings and the following description. Other features, purposes, and advantages will become apparent from the description and drawings, as well as from the claims. [Brief explanation of the drawing]

[0057] [Figure 1] Perspective views of rod adjusters in various embodiments are shown. [Figure 2] Additional perspective views of rod retractors in various embodiments are shown. [Figure 3] Each shows a different side view of a rod straightener according to various embodiments. [Figure 4] Each shows a different side view of a rod straightener according to various embodiments. [Figure 5] Figures 3 and 4 show the top and bottom views of the sleeve for the rod straightener, respectively. [Figure 6] Figures 3 and 4 show the top and bottom views of the sleeve for the rod straightener, respectively. [Figure 7] Perspective views of spinal fixation systems in various embodiments are shown. [Figure 8] Figure 7 shows different perspective views of the spinal fixation system according to various embodiments. [Figure 9] These are schematic side views of rod straighteners and related electronic devices according to various embodiments. [Figure 10] This is a schematic side view of a rod restorer and associated electronic equipment according to various additional embodiments. [Figure 11] This is a schematic side view of a rod straightener and associated electronic equipment according to various further embodiments. [Figure 12] This is a system diagram showing spinal fixation systems and devices in various embodiments. [Figure 13] This is an exemplary data flow diagram illustrating reordering using various embodiments. [Figure 14] These are some side views of spinal fixation systems in various embodiments. [Figure 15] This is a top view of a visual display mechanism in various embodiments. [Figure 16] This is a schematic diagram of a visual display mechanism with various additional embodiments. [Figure 17] The following are side views of exemplary drivers in various embodiments. [Figure 18] Figure 17 shows exploded perspective views of an exemplary driver according to various embodiments.

[0058] Please note that the drawings of various embodiments are not necessarily to scale. The drawings are intended to show only typical embodiments of this disclosure and should not be considered to limit the scope of the embodiments. In the drawings, similar numbers represent similar elements across drawings. [Modes for carrying out the invention]

[0059] Various exemplary embodiments of devices and techniques for rod reduction during spinal instrumentation procedures are described herein. For clarity, not all features of actual embodiments are necessarily described herein. Of course, it will be understood that in developing such actual embodiments, numerous implementation-specific decisions will have to be made, which will differ from implementation to implementation, such as compliance with system-related and business-related constraints, in order to achieve the developer's specific goals. Furthermore, it will be understood that such development efforts, although complex and time-consuming, are nevertheless routine work for those skilled in the art who are interested in this disclosure. The rod reduction devices and related systems, program products, and methods described herein have various inventive features and components, both individually and in combination, that guarantee patent protection.

[0060] It should be understood that any given element of the disclosed embodiments of the present invention can be embodied in a single structure, a single step, a single substance, etc. Similarly, a given element of the disclosed embodiments can be embodied in multiple structures, steps, substances, etc.

[0061] This disclosure provides, at least in part, rod reduction instruments, associated fixation systems, methods, and monitoring systems that beneficially incorporate reduction feedback systems to improve the effectiveness of spinal fixation procedures and reduce the opportunity for operator (e.g., surgeon) error when performing such procedures. Various embodiments disclosed can improve patient outcomes compared to conventional spinal fixation procedures. Disclosed embodiments can provide real-time and / or postoperative feedback on reduction procedures and can improve both current procedure outcomes and future surgical outcomes. In specific cases, the reduction feedback system can provide the operator with information on desired reduction sequencing in multilevel reduction procedures, thereby reducing or avoiding instrument overload at any given time during the procedure.

[0062] Components with common symbols in the diagram are considered substantially equivalent for explanatory purposes, and redundant explanations of these components are omitted for clarity.

[0063] Figures 1 and 2 show perspective views of exemplary rod reduction devices or reducers in various embodiments. It is understood that the disclosed embodiments may be applicable to several rod reduction devices of various form factors. Additional rod reduction devices, such as those disclosed in U.S. Patent No. 10,136,927 (which is incorporated herein by reference in whole), may benefit from the various disclosed embodiments. In various embodiments, the exemplary rod reduction device (reduction device) is used during the placement of a fixation structure 10 onto a patient's spine. The fixation structure 10 comprises anchor members 12 connected by fixation rods 14 locked to each anchor 12. The anchors 12 are implanted in each vertebra to be fixed by the structure 10. For example, two anchors 12 can be used to fix two vertebrae together, three can be used to fix three vertebrae together, four can be used to fix four vertebrae together, and so on. In addition, multiple anchors 12 may be used to fix each vertebra to an adjacent vertebra (for example, four anchors 12 can be used to join two vertebrae together). An anchor 12 comprises a bone anchor 18 and a housing 20 for capturing and locking a fixing rod 14. The bone anchor 18 may be a bone screw suitable for stable fixation to a vertebra (e.g., pedicle or vertebral body), as shown. The bone anchor 18 may also include other fixing devices (e.g., hooks, staples, clamps, etc.). The housing 20 has a base that attaches to the bone anchor and a pair of upright arms that together form a rod channel 22. The housing also includes a mechanism for locking the fixing rod 14 in place within the rod channel 22. For example, the mechanism may include locking cap guides and forward features arranged on the inner surface of each arm, interacting with complementary features on the locking cap. The base may be fixed to the anchor 18, or it may be coupled so that the housing 20 can rotate in one or more directions (e.g., multi-axis). The housing 20 also includes one or more instrument engagement features for releasably coupling to one or more instruments during implantation.Examples of anchors configured for use with the retractors described herein are shown and described in U.S. Patent No. 9,198,698 ("Minimally Invasive Spinal Fixation System and Related Methods") and U.S. Patent No. 11,051,861 ("Rod Reduction Assemblies and Related Methods"), the entire contents of each of these are incorporated herein by reference. The retractors described herein engage with one or more of the anchors 12 of the fixation structure 10 to facilitate the alignment and advancement of the rod 14 into the rod channel 22 of each anchor. In certain embodiments, the fixation structure 10 includes a pedicle screw.

[0064] Referring here to Figures 1 to 6, a rod restorer (or simply restorer) 100 according to one exemplary embodiment is shown. The restorer 100 is coupled to both arms of the anchor 12 and configured to apply a downward force to the rod 14. The downward force on the rod acts to pull the rod 14 and the anchor housing 20 together until the rod 14 is fully seated in the rod channel 22. A locking mechanism, such as a locking cap, is then at least partially engaged before the restorer 100 is detached from the anchor 12, allowing the rod 14 to be captured in the housing 20. The restorer 100 comprises a coupling unit 102 (Figure 2) that connects to the anchor 12 and a translation unit 104 (Figure 2) that translates relative to the coupling unit 102 to bias the rod 14 toward the anchor.

[0065] The coupling unit 102 comprises a base member 106 and first and second mounting arms 108 pivotally coupled to the base member 106. The base member 106 is an elongated, substantially tubular member having a proximal portion 110, a central portion 112, a distal portion 114, and a central lumen 116 (Figure 6) extending longitudinally through the entire length of the base member 106. The proximal portion 110 includes a handle 118 that provides a gripping area for the user to grasp the reducer 100. Above the handle 118 is a head 124 (Figures 1-2) that allows other instruments to be coupled to the reducer 100. The head 124 may be configured to mimic the proximal end of a minimally invasive screw guide so that any instrument that engages with or couples with the guide (e.g., a vertebral detorsion assembly, a reverse torque, etc.) can also engage with or couple with the reducer 100. Although not shown, the proximal portion 110 may include a threaded portion formed inside the proximal portion 110 (i.e., at the proximal end of the lumen 116) for thread engagement with the translation unit 104. In a particular embodiment, the drive knob 170 is located between the proximal portion 110 and the central portion 112.

[0066] Figures 7 and 8 show a spinal fixation system 210 configured to be constructed by introducing the posterior spinal fixation structure described above, according to an exemplary embodiment. In one example, the spinal fixation system 210 comprises a pedicle screw 212, an elongated spinal rod 214, and a guide assembly 216. The pedicle screw 212 is inserted bilaterally or unilaterally into multiple vertebrae across one or more levels. In additional embodiments, a fixation anchor (such as one described in U.S. Patent No. 9,198,698, incorporated herein by prior reference) may be used instead of the pedicle screw 212 in one or more vertebrae. The spinal fixation system 210 may further include, for example, a reduction device (also called a reducer) 218 ​​shown in Figures 7 and 8, as well as any of the various devices configured to perform the installation and assembly of the spinal fixation structure, including rod inserters, compression devices, lock screw inserters, guide adjusters, tap guides, and dilators, various embodiments of which are described in further detail in U.S. Patent No. 9,198,698, which is incorporated herein by prior reference.

[0067] Figure 9 shows exemplary embodiments of the rod reduction device (or simply the device) 300 according to various embodiments. As shown in Figure 9, the device 300 comprises a rod reducer (or simply the reducer) 302, which may be similar in form and / or function to reducers (which may be more), e.g., reducer 100 and / or reducer 218, as described according to any embodiment of this specification. In certain embodiments, the reducer 302 has a proximal end 304 and a distal end 306. The distal end 306 is configured to engage with the spinal rod to seat the spinal rod within the pedicle screw receiver (as described, for example, with respect to Figures 1 to 4). In various embodiments, the rod reducer 302 is configured to fully seat the spinal rod (e.g., spinal rod 214 in Figure 8) within the pedicle screw receiver (e.g., the receiver of the pedicle screw 212 in Figure 8, also called the rod channel 22 in Figure 2).

[0068] In certain embodiments, the instrument 300 includes a sensor 308 configured to detect the load applied to the spinal rod by the rod reducer 302 while seating the spinal rod in the pedicle screw receiver. In certain examples, the sensor 308 includes one or more of a strain gauge, a pressure-sensitive film, or a capacitive sensor. In various embodiments, the sensor 308 is configured to sense the load applied, for example, to the spinal rod via the rod reducer 302. In certain examples, the sensor 308 is configured to indicate the pressure and / or torque applied, for example, to the spinal rod by the rod reducer 302.

[0069] In certain embodiments, the sensor 308 is configured to determine data relating to at least one of the following: a bone anchor (e.g., anchor 12 in Figures 1-6 and / or pedicle screw 212 in Figures 7 and 8), a vertebral rod (e.g., rod 14 in Figures 1-6 and / or vertebral rod 214 in Figures 7 and 8), or a reducer 302. In certain examples, the sensor 308 provides load data including tensile load between the rod and the bone anchor when the rod is at least partially seated within the bone anchor. In additional examples, the sensor 308 provides load data including torsional force data.

[0070] In certain embodiments, the sensor 308 is located between the proximal end 304 and the distal end 306 of the rod retractor 302. For example, as shown in Figure 9, the retractor 302 comprises a multi-section shaft 310 including a first section 312 and a second section 314, and the sensor 308 is mounted axially between sections 312 and 314. In an additional example, as shown in Figure 10, the sensor 308 is coupled to the proximal end 304 of the rod retractor 302, for example, to the end of the rod retractor 302.

[0071] In certain embodiments, the housing 316 is coupled to the reducer 302, for example, at the proximal end 304 of the reducer 302. In certain cases, the housing 316 includes electronic equipment 318 as described herein. In additional embodiments, the electronic equipment 318 is configured to communicate with a remote spinal immobilization management system (e.g., wireless and / or wired connection). In certain cases, the electronic equipment 318 includes at least a portion of the reduction feedback system 320.

[0072] Sensor 308 is coupled to a reduction feedback system 320, which is configured to a) receive load data from the sensor indicating the load applied to the spinal rod by the rod reducer 302, and b) provide an indicator of the load data so that the indicator is detectable by an operator of the device 300. As described herein and shown by dashed lines in Figure 9, the reduction feedback system 320 may be at least partially housed within a housing 316 mounted on the proximal end 304 of the reducer 302. In additional embodiments, the reduction feedback system 320 may be at least partially housed within a centralized spinal fixation management system, as further described herein.

[0073] In certain cases, the housing 316 is modular and / or disposable. That is, in certain cases, the housing 316 substantially includes a reduction feedback system 320 that can be selectively coupled and / or disconnected from the proximal end 304 of the reducer (e.g., using selective couplers such as male / female threads, snap-fit ​​connectors, pressure-fit or press-fit connectors, adhesives, etc.). In some of these cases, the reduction feedback system 320 is disposable, i.e., intended for single use during spinal fixation procedures. In these examples, the reduction feedback system 320 may include onboard electronics intended for limited specifications, such as signal conditioning electronics such as sensors, power, and interface circuits for processing and outputting signals. In certain cases, the interface circuit comprises a signal processor, such as a digital signal processor (DSP), a logic engine for filtering / conditioning signals, and a controller for controlling onboard functions such as transmitting signals to external components such as displays and external receivers. In certain examples, the housing 316 is selectively coupled to an existing nut on the proximal end 304 of the retractor 302. In additional examples, the housing 316 is selectively coupled to the central lumen 116 or another part of the body of the retractor 302.

[0074] In certain examples, as shown in Figure 11, the sensor 308 is housed within the housing 316 together with at least a portion of the corrective feedback system 320. In these embodiments, the sensor 308 can be directly coupled to the corrective feedback system 320, or at least a portion of the corrective feedback system 320 located within the housing 316. In certain cases, the electronic equipment 318 is powered by an onboard power supply 321 in the housing 316 (e.g., one or more batteries, a charging device, and / or a wired power supply).

[0075] A schematic diagram of the reduction feedback system 320, including the data flow related to components that interact with the system 320, is shown in Figure 12. As described herein, the reduction feedback system 320 can function as an onboard system (e.g., on the instrument 300) and / or as a physically separate system (e.g., coupled via wireless and / or wired connections). In certain cases, as described herein, the reduction feedback system 320 may be hosted as part of a spinal fixation system 400, or otherwise implemented, as described, for example, in U.S. Patent Application No. 16 / 562,411 (Systems and Methods for Spinal Surgical Procedures), and the whole is incorporated herein by reference.

[0076] In certain embodiments, the reduction feedback system 320 comprises a controller 322 (e.g., one or more microcontrollers) having at least one processor (PU) 324 (e.g., one or more microprocessors), coupled with or including a memory 326 (e.g., one or more storage components such as a memory chip and / or chipset). The memory 326 stores instructions (e.g., reduction feedback (RF) instructions 328) that, when executed by the PU(s) 324, cause the PU 324 to i) compare load data acquired from the sensor 308 with a load threshold of the reduction device 302, and ii) provide an indicator of whether the load data meets or does not meet the load threshold of the reduction device 302. In certain cases, the load threshold includes a load range of the reduction device 302 indicating a desired load on an anchor (e.g., anchor 12 in Figure 1, or pedicle screw 212 in Figures 7, 8). In various embodiments, the load threshold includes a range with upper and lower limits, which can, for example, account for some variation in measurements based on a known measurement error margin of sensor 308. In additional embodiments, the load threshold includes a load value that accounts for a known measurement error of, for example, 1 percent, 2 percent, or 3 percent. In certain embodiments, the load threshold is at least partially based on a model that correlates clinical data representing patient-specific bone quality with screw extraction. This clinical data can be incorporated into a model stored in reduction feedback command 328 and can be made updatable, for example, as further data becomes available.

[0077] In certain embodiments, the load data represents, at least partially, the amount of torque applied to the locking screw while tightening the locking screw within the pedicle screw receiver (Figure 8) and the compressive force applied to the reducer 302. In some of these cases, for example, if the load data does not meet the load threshold, the indicator may include an indicator of the amount by which the torque applied to the spinal rod should be modified to meet the load threshold of the reducer 302.

[0078] In certain embodiments, the load threshold(s) define the maximum allowable load applied to the spinal rod 214 (Figure 8) by the retractor 302 while seating the spinal rod in the receiver of the pedicle screw 212 (Figure 8), also known as the rod channel 22 (Figure 2). In certain cases, the maximum allowable load is a) approximately 50 pounds (222N) ~approximately £250 (1112N) b) Approximately 25 pounds (111N) ~approximately £150 (667N) , or c) about 25 pounds (111N) ~approximately £75 (334N) It is one of them. In certain cases, the maximum allowable load ranges (a) to (c) can be combined, for example, about 50 pounds. (222N) ~approximately £150 (667N) Approximately 25 pounds (111N) ~approximately £250 (1112N) And so on.

[0079] Continuing to refer to Figure 12, an exemplary diagram of a reduction feedback system 320 for managing a set of rod reducers 302a, 302b, and 302c is shown. In these cases, the reduction feedback system 320 may be part of a spinal fixation system 400, configured to manage the reducers 302 in a multilevel reduction procedure, for example, where two or more vertebral adjustments are performed along the patient's spine. In various embodiments, the set of rod reducers 302 are engaged with the spinal rods, and the reduction feedback system 320 is configured to be communicatively coupled to each of the rod reducers (e.g., wirelessly or via wired means) and to receive load data indicating the load applied to the spinal rods by each rod reducer 302. Although this diagram includes a small number of rod reducers 302a, 302b, and 302c for simplicity of explanation, it should be understood that the set of rod reducers may include up to 20 rod reducers in total, arranged in subsets of 10 on each side of the patient's spine. Figure 14 shows an exemplary embodiment depicting six retractors 302a-f positioned on one side of the patient's spine, corresponding to six additional retractors 302 (not shown) on the opposite side of the patient's spine during the alignment procedure (a total of 12 retractors 302).

[0080] In certain embodiments, the reduction feedback system 320 is coupled to sensors 308a, 308b, 308c, etc., either directly (via wireless or wired connection, etc.) or via an onboard reduction feedback system 320 in each of the reduction devices 302a, 302b, 302c, etc. In certain cases, the reduction device 302 (including sensor 308) is configured to communicate with the reduction feedback system 320, for example, via a communication device in the electronic equipment 318 and / or spinal immobilization system 400 (Figure 12). The communication device(s) may include one or more transmitters and / or receivers (e.g., wireless and / or wired transmitters / receivers). In various embodiments, the communication device is configured for multiple communication protocols, such as wireless protocols like WiFi®, Bluetooth®, BLE, Zigbee®, and wireless and intercom communication, and / or wired connections (e.g., fiber optic connections).

[0081] In any case, the reduction feedback system 320 (in particular, PU(s) 324) is configured to compare load data received from one or more sensors 308 with corresponding load thresholds of those sensors 308 in order to determine whether one or more reduction devices 302 are properly loaded (e.g., overloaded or underloaded). Figure 13 shows an exemplary data structure of an RF instruction 328 for comparing load data 340 with a set of thresholds 350 in order to determine a) whether a particular reduction device 302 is underloaded or overloaded, and b) the reduction sequence for adjusting the loads on multiple reduction devices 302. Based on the load data 340, the RF instruction 328 provides a reduction (sequencing) instruction 360, which includes identifiers of one or more reduction devices 302 and the amount of load adjustment. In certain cases, the reduction instruction 360 includes a reduction sequencing instruction, such as when multiple load data 340 are acquired as part of a multi-level reduction procedure.

[0082] Referring to Figures 12 to 14, in various embodiments, the reduction feedback system 320 is configured to compare load data 340 from each of a plurality of sensors 308 and provide a reduction command 360, the reduction command 360 may include an indicator of relative load between at least two reducers 302. For example, the relative load indicator may show whether a given rod reducer (e.g., reducer 302b) is more loaded, less loaded, or equally loaded with respect to any one or all of the additional rod reducers in the set (e.g., reducers 302a, 302c). In various embodiments, the load data 340 is updated continuously or periodically during a matching procedure, and as a result, the new load data 340 is processed by the reduction feedback system 320 over an extended period during the procedure. In specific cases, the load data 340 is updated whenever a change in load is detected in one of the sensors 308, for example, with each adjustment by the surgeon. In these cases, the reset command 360 is continuously updated to reflect the relative load to each resetter 302 in the set. In an exemplary embodiment, the relative load indicator always includes an indicator for the lowest load rod resetter 302 in the set of resetters, and as a result, the system 320 is configured to update the relative load indicator over time as the load data for at least one of the resetters 302 in the set is updated.

[0083] As shown in Figure 13, the reduction command 360 may include an indicator of the reduction order (or sequencing) of a set of reducers 302a, 302b, 302c, etc., based on the received load data 340. For example, the reduction order indicator may include a reduction command 360 for multi-stage reduction of a set of reducers 302. In particular, Figure 13 shows an exemplary embodiment in which the system 320 i) compares load data 340 from two or more reduction instruments (e.g., reducers 302) to a set of thresholds 350, and ii) provides an indicator that prioritizes a modified load (e.g., increased or decreased load) of a particular reduction instrument (e.g., reducer 302b) over at least one additional reduction instrument (e.g., reducer 302a) based on whether the load data 340 from two or more reduction instruments 302a, 302b satisfy the set of load thresholds. In some cases, the threshold 350 includes absolute load thresholds for each reducer 302 (e.g., absolute load thresholds 1, 2, 3). These absolute load thresholds may represent the minimum and / or maximum allowable load values ​​of load data 340 (e.g., detected by sensors(s) 308). In certain cases, the absolute load thresholds vary based on at least one of the following: a) the location of a given rod reducer (e.g., reducer 302) along the patient's spine, b) the patient's anatomical structure (e.g., spinal curvature), or c) the patient's bone quality. For example, the RF command 328 may be adjusted or otherwise tuned according to patient-specific input 370, which may include patient characteristics (e.g., physiological and / or anatomical characteristics such as intervertebral spacing, angulation of one or more sections of the patient's spine), and patient's bone quality (e.g., a mechanical bone quality scale such as the T-score (relative health compared to a standard), or a quality indicator derived from a bone scan such as a CT scan or MRI). For example, the absolute load threshold can be adjusted based on the patient's bone quality (e.g., a lower maximum absolute load threshold for lower bone quality) and / or the angulation of the adjacent vertebrae on which the retractor 302 is operating (e.g., a higher minimum absolute load threshold for a higher angulation value). In addition, the RF command 328 can be adjusted based on the location of the retractor 302 along the spine, for example, using different absolute load thresholds at L2 versus L4.

[0084] Furthermore, the load threshold 350 may include relative load thresholds (e.g., relative load threshold 1, relative load threshold 2) for each of two or more rod reduction devices (e.g., reduction devices 302a, 302b, 302c, etc.). In these cases, the relative load thresholds can define the maximum allowable difference in load between any two reduction devices 302 and / or between any two adjacent reduction devices (e.g., between reduction devices 302a and 302b in Figure 14, or between reduction devices 302d and 302e). These relative load thresholds may be used to determine the reduction order, for example, to prioritize the load of a particular reduction device 302a over another reduction device 302c. In the example shown in Figure 13, the load data 340 is processed using absolute load thresholds before relative load thresholds, but this order can be reversed in various embodiments. In additional embodiments, the load thresholds and relative loads can be used to construct a reduction order to instruct a user, for example, a surgeon or other medical professional. In some cases, the load data 340 of the reducer(s) 302 is analyzed based on one or more of the following: i) a threshold for a given reducer(s) 302 or an aggregate threshold for a group of reducers(s) 302 to avoid exceeding the threshold for the reducer(s) 302; ii) relative loads between any two or more reducers(s) 302 to avoid exceeding a difference threshold; iii) upper and / or lower reduction limits during the operation of the reducer(s) 302; or iv) following a reduction sequence defined by the preoperative plan. In certain cases, after comparing the load data 340 of two or more reducers 302a, 302b, 302c, etc., the system 320 provides at least one load adjustment (e.g., load adjustment 1, load adjustment 2, etc.), which is placed in an ordered list for use as a reduction (sequencing) command 360. For example, the resizing (sequencing) command 360 may include load adjustment 1 (e.g., adjusting the torque of resizing device 302b by a quarter turn clockwise or a pressure increase of X lbs) and subsequent load adjustment 2 (e.g., after load adjustment 1: adjusting the torque of resizing device 302a by a half turn counterclockwise or a pressure decrease of Y lbs).

[0085] In various embodiments, due to the interrelated nature of the loads across different reducing devices (e.g., reducing devices 302a, 302b, etc.), the reducing sequencing command 360 may, in certain cases, include a multi-reducing device sequence that adjusts the load on a given reducing device 302 two or more times in a complete sequence. For example, the reducing sequencing command 360 may include an instruction to first adjust the load on the first reducing device 302a by an amount that does not fully seat the rod in the anchor receiver, then adjust the load on the second reducing device 302b, and then further adjust the load on the first reducing device 302 by an amount that fully seats the rod in the anchor receiver.

[0086] In certain embodiments, as shown, for example, in Figure 12, the spinal fixation system 400 may further include an interface 380 that enables interaction between the reduction feedback system 320 and a surgeon, medical professional(s), and / or other operator in the spinal fixation procedure room. In some cases, the spinal fixation system 400 communicates with a reducer(s) 302 via a communication device 390, such as a wireless and / or wired communication device as described herein. The interface(s) 380 may include any conventional visual, tactile, and / or auditory interfaces that can enable the communication of reduction feedback information to the surgeon, medical professional, and / or operator during the spinal fixation procedure. In certain cases, the interface(s) 380 may include a graphical user interface (GUI) that may include a liquid crystal display (LCD), one or more touchscreens, a virtual medical assistant system (e.g., a voice-based command system), and the like. In certain cases, as shown in Figures 9 to 11, the interface(s) 380 may include a visual display system 410 and / or a tactile display system 420 for providing an indicator of load data 340 (Figure 13) detected by the sensor 308 in the retractor(s) 302. That is, in certain embodiments, at least a portion of the visual display system 410 and / or the tactile display system 420 is provided on the retractor(s) 302 (e.g., on each retractor coupled to the housing 316). In additional embodiments, a portion of the visual display system 410 and / or the tactile display system 420 may be provided on a central interface, for example, the interface 380 of the spinal immobilization system 400.

[0087] In certain embodiments, the tactile indicator system 420 may include at least one vibratory tactile actuator configured to inform the surgeon (or other medical professional or operator) that the decompressor 302 requires further load and / or is approaching an overload condition. For example, the tactile indicator system 420 may be configured to trigger a vibration cue (e.g., by vibrating the housing 316) when the load on a given decompressor 302 is approaching a maximum absolute load threshold. In some cases, the tactile indicator system 420 may be integrated with or otherwise connected to the housing 316 to initiate a vibration response to load data from a corresponding sensor 308 that is approaching and / or exceeding a maximum absolute load threshold. In additional cases, the tactile indicator system 420 may be configured to provide different vibration cues for the load on the decompressor, e.g., a first set of vibration cues indicating underload and a second set of vibration cues indicating overload or approaching the load limit.

[0088] Figure 15 shows an example of the proximal end 304 of a reducer 302 (e.g., the proximal end of the housing 316), which includes a visual indicator system 410 having a set of lights 430 configured to illuminate in at least two different patterns to indicate the distinction of load data of the reducer 302. This example shows lights 430 of different colors, but any progressive illumination configuration can be used to provide different patterns. For example, an annular arrangement of lights 430 as shown in Figure 15 may be configured to provide color distinctions, e.g., green to indicate a desired load, yellow approaching an overload, and red to indicate an overload. In some cases, this annular arrangement of lights 430 may illuminate in at least two different patterns, having the same or similar colors (to indicate over / underload). The annular illumination arrangement is just one of many possible arrangements along with the embodiments herein, and thus the load of a given reducer 302 can be visually indicated using linear light arrays, light bars, light intensity distinctions, etc.

[0089] Figure 16 shows another example of a visual display system 410 (e.g., via interface 380) including a reduction display 450 that includes a bar graph showing load levels (e.g., on a scale of 0 to 20) across a set of 10 different decompressors 302. In this example, the bar graph can be dynamically updated when changes in load data are detected for one or more decompressors 302, thereby allowing an observer (e.g., a surgeon, medical professional, or other operator) to see which decompressor 302 is under the least load or can otherwise withstand an increased load, and which decompressor(s) 302 are approaching their load limit. In some of these cases, the reduction display 450 can utilize color distinctions (not shown) to indicate sequencing or otherwise supplement the display of the lowest load decompressor 302, e.g., the first decompressor 302 that should receive an increased load.

[0090] Returning to Figure 12, in various additional embodiments (indicated by dashed lines as optional), the reduction feedback system 320 is further coupled with one or more additional fixation devices 500 which may include one or more sensors 308, such as load sensors as described herein. In particular, the fixation device 500 includes a driver configured to tighten a locking screw in a bone anchor receiver (e.g., a receiver in a bone anchor (e.g., anchor 12 in Figures 1-6 and / or pedicle screw 212 in Figures 7 and 8)) and lock a rod (e.g., rod 14 in Figures 1-6 and / or spinal rod 214 in Figures 7 and 8) against the bone anchor. An example of such a fixation device is provided in U.S. Patent Application Publication No. 2020 / 0297393 (U.S. Patent Application No. 16 / 898,713), which is incorporated herein by reference in its entirety. In further specific cases, the fixation device 500 includes a guide (sometimes also called a “guide tube”) for defining the trajectory of the device and / or screw during spinal surgery. Examples of fixation devices such as guides and guide tubes are provided in U.S. Patent Application Publication No. 2021 / 0085485 (U.S. Patent Application No. 16 / 995,602), which is incorporated herein by reference in its entirety.

[0091] Referring to additional mounting fixtures, Figures 17 and 18 show side and exploded perspective views, respectively, of examples of the driver 600 according to various embodiments. In this case, the driver 600 has a proximal end 610 and a distal end 620, the distal end 620 being configured to engage with and tighten a locking screw. The sensor 308 is shown mounted coaxially with the driver 600, for example, between or within sections 630A, 630B of the driver shaft 630. In certain cases, the housing for the sensor 308 comprises one or more mating features 640 for coupling with complementary mating features 650 in the shaft 630. In certain additional cases, for example, a housing 316 mounted on the shaft 630 near the proximal end 610 includes one or more additional sensors 308 and / or electronic equipment 318, power supplies 321 and / or display systems 410, 420, as described with reference to Figures 9 to 11. In the example of the driver 600 shown in Figures 17 and 18, the sensor(s) 308 may be configured to provide torsional force data indicating the torsional force applied to the locking screw while tightening the locking screw within the receiver, for example, in the process of locking the rod against a bone anchor. In certain cases, the driver(s) 600 may be configured to be coupled with the rod reducer(s) 302 described herein. In certain embodiments, the driver(s) 600 may be inserted through the rod reducer(s) 302 to deliver and tighten the locking screw into the receiver, thereby locking the rod against the bone anchor. According to certain embodiments, the sensor(s) 308 within the driver(s) 600 may be configured to provide torsional force data relating to the torsional force applied to the locking screw by the driver(s) 600. In some examples, the driver(s) 600 may be deployed as a “finishing” driver or “final tightening” driver configured to tighten the locking screw in its final or finishing stage. In such cases, the sensor(s) 308 within the driver 600 may be configured to provide data on the torsional force applied to the locking screw by the driver 600 during the final or finishing stage.

[0092] In yet another embodiment, sensors 308 within the fixation device 500 described herein (e.g., driver 600, rod reducer 302 and / or guide tube) may be configured to provide data on the load applied to the rod by the fixation device 500 while seating the rod in the receiver of the bone anchor, and / or data on the tensile load between the rod and the bone anchor when the rod is at least partially seated in the bone anchor. In a particular embodiment, both torque and compression data are recorded by sensors 308 on the fixation device 500 and provided to the reduction feedback system 320 for analysis and / or operation (e.g., to adjust reduction commands). It should be understood that torque and / or compression data detected by sensors 308, such as sensors mounted on the driver 600 and / or rod reducer 302, may represent an estimate or correlation indicator of torque and / or compression applied to a device or component that is not in physical contact with the sensor 308. For example, a sensor 308 on a tool 500 (e.g., a driver 600) can be configured to detect torque in the tool 500, which is transmitted to a locking screw in contact with the distal end of the tool. Similarly, a sensor 308 on a tool 500 (e.g., a rod reducer 302) can detect compression in the tool 500, which is transmitted to the rod.

[0093] In additional embodiments, one or more immobilization devices described herein, such as a rod reducer 302, an immobilization device(s) 500, etc., may be communicatively coupled (for example, via a spinal immobilization system 400) to a navigation system(s) configured to detect the position of the device(s). In an exemplary depiction of Figure 12, a navigation system 700 (indicated by dashed lines as optional) is coupled to a reduction feedback system 320 to provide navigation information regarding the position of the device. For example, the navigation system 700 may include an optical tracking system such as a camera or laser-based tracking system, a Global Positioning System (GPS), an Inertial Measurement Unit (IMU), etc. In a particular case, the navigation system 700 is configured to determine the distance traveled by the device when the device changes position, and the navigation system 700 communicates this to the reduction feedback system 400. One or more components of the navigation system 700 may be mounted on or otherwise coupled to one or more of the reduction devices, housed in or otherwise integrated with a housing, such as housing 316 (Figures 9-11). For example, components of the navigation system such as GPS and / or IMU may be housed in housing 316. In certain examples, the navigation system 700 and / or parts thereof may be fixed to parts of rod reducers 302, fixation devices 500, etc., and physically separated from housing 316. In some of these cases, for example, if housing 316 and / or other electronic equipment packages are modular, the navigation system 700 may remain independently coupled to rod reducers 302, fixation devices 500, or other devices. In additional embodiments, the spinal fixation system 400 includes or is coupled to the navigation system 700 located outside housing 316 and / or reduction devices.

[0094] Referring to Figures 12 and 13, in additional embodiments, the reduction feedback system 320 is configured to provide postoperative data and analysis of reduction procedures and / or device use, for example, to improve future procedures and / or diagnose inefficiencies in past procedures. In certain embodiments, the reduction feedback system 320 is configured to update the RF instruction 328 based on identified inefficiencies or errors in reduction sequencing and / or device use during a given procedure. In certain embodiments, the reduction feedback system 320 includes a logic engine configured to iteratively modify the RF instruction 328, for example, for each procedure.

[0095] As described herein, reduction devices, reduction feedback systems, and spinal fixation systems disclosed according to various embodiments offer many advantages over conventional spinal fixation devices and systems. For example, the disclosed devices, systems, feedback systems, and methods can improve the effectiveness of spinal fixation procedures and reduce operator (e.g., surgeon) errors when performing such procedures. Various disclosed embodiments can improve patient outcomes compared to conventional spinal fixation procedures. In addition, the disclosed embodiments can provide real-time and / or postoperative feedback regarding reduction procedures, improving both current procedure outcomes and future surgical outcomes. In certain embodiments, the reduction feedback system can provide the operator with information regarding desired reduction sequencing in multilevel reduction procedures, thereby reducing or avoiding instrument overload at any given time during the procedure.

[0096] The functions described herein, or parts thereof, and various modifications thereof (hereinafter, "functions") may be implemented, at least in part, through computer program products, such as computer programs tangibly embodied in information carriers, such as one or more non-temporary machine-readable media, for execution by or control of the operation of one or more data processing devices, such as programmable processors, computers, multiple computers, and / or programmable logical components.

[0097] Computer programs can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, such as a standalone program, or as modules, components, subroutines, or other units suitable for use in a computing environment. Computer programs can be deployed to run on a single computer, on multiple computers at a single site, or on multiple computers distributed across multiple sites and interconnected by a network.

[0098] Operations related to implementing all or part of the functionality may be performed by one or more programmable processors that execute one or more computer programs to perform the functions of the calibration process. All or part of the functionality may be implemented as dedicated logic circuits, e.g., FPGAs and / or ASICs (Application-Specific Integrated Circuits). Processors suitable for executing computer programs include, for example, both general-purpose microprocessors and dedicated microprocessors, as well as any one or more processors of any type of digital computer. Generally, a processor receives instructions and data from read-only memory or random-access memory or both. The components of a computer include a processor for executing instructions and one or more memory devices for storing instructions and data.

[0099] In various embodiments, components described as “joined” to one another may be joined along one or more interfaces. In some embodiments, these interfaces may comprise joints between different components, and in other cases, these interfaces may include interconnections that are formed rigidly and / or integrally. That is, in some cases, components that are “joined” to one another may be formed simultaneously to define a single continuous member. However, in other embodiments, these joined components may be formed as separate members and then joined by known processes (e.g., soldering, fastening, ultrasonic welding, bonding). In various embodiments, electronic components described as “joined” may be linked via conventional wired and / or wireless means so that these electronic components can communicate data with one another. Furthermore, subcomponents within a given component may be considered to be linked via conventional paths that are not necessarily illustrated.

[0100] While the features of the present invention described herein are described in relation to preferred embodiments for achieving the objective, it will be understood by those skilled in the art that modifications can be achieved by taking these teachings into consideration without departing from the spirit or scope of the invention. Furthermore, although the present invention has been described in relation to preferred uses in applications to the spine, it will be understood that it can be applied to various other uses where surgical fixation, for example, fixation of long bones 213, is desired.

[0101] Several embodiments have been described. Nevertheless, additional modifications can be made without departing from the scope of the concept of the present invention as described herein, and it will be understood that other embodiments fall within the scope of the following claims.

Claims

1. A rod reduction device adapted for use with a spinal fixation system, A rod reducer having a proximal end and a distal end, wherein the distal end of the rod reducer is configured to engage with a spinal rod to seat the spinal rod within a pedicle screw receiver, A sensor configured to detect the load applied to the spinal rod by the rod reducer while the spinal rod is seated in the pedicle screw receiver, A correction feedback system coupled to the aforementioned sensor, Load data indicating the load applied to the spinal rod by the rod reducer is received from the sensor. The load data is compared with the load threshold of the rod restorer. The system is configured to provide an indicator of the load data detectable by the operator of the rod reduction device, the indicator of the load data including an indicator of whether the load data meets or does not meet the load threshold of the rod reduction device. The load data is compared with additional load data detected by an additional set of sensors coupled to an additional set of rod adjusters. It is configured to provide an indicator of the relative load of the rod straightener compared to at least one of the additional rod straighteners in the set, The relative load indicator indicates whether the rod restorer is more loaded, less loaded, or loaded equally with respect to the additional rod restorer in the set. A rod reducing device comprising a reduction feedback system configured to update an indicator of the relative load over time as load data relating to the rod reducing device or at least one of the additional rod reducing devices in the set is updated.

2. The rod reducer according to claim 1, further comprising a housing mounted on the proximal end of the rod reducer, wherein the reduction feedback system is disposed within the housing.

3. The rod reduction device according to claim 1, wherein the load data at least partially represents the amount of torque applied to the lock screw during tightening of the lock screw within the pedicle screw receiver and the compressive force applied to the rod reducer, and the indicator of whether the load data meets or does not meet the load threshold includes an indicator of the amount by which the compressive force applied to the spinal rod should be modified to meet the load threshold of the rod reducer, and the load threshold is at least partially based on a model that correlates clinical data representing patient-specific bone quality with screw extraction.

4. The load threshold defines the maximum allowable load applied to the spinal rod by the rod reducer while seating the spinal rod within the pedicle screw receiver, and the maximum allowable load is a) 50 pounds (222N) to 250 pounds (1112N), b) 25 pounds (111 N) to 150 pounds (667 N), or c) The rod reduction device according to claim 1, wherein the force is between 25 pounds (111 N) and 75 pounds (334 N).

5. The rod reduction device according to claim 1, wherein the rod reduction device is configured for use in a multilevel reduction procedure, the indicator of the load data includes an indicator of the relative load of the rod reduction device compared to the set of additional rod reduction devices engaged with the spinal rod.

6. The rod reduction device according to claim 1, wherein the spinal fixation system includes a set of rod reduction devices having a set of rod reducers engaged with the spinal rod, and the reduction feedback system is communicably coupled to each of the rod reduction devices and configured to receive load data indicating the load applied to the spinal rod by each rod reducer.

7. The rod reduction device according to claim 6, wherein the reduction feedback system is further configured to provide an indicator of the reduction sequence of the set of rod reduction devices based on the received load data.

8. The reduction feedback system, The load data from two or more of the rod reduction devices in the set is compared with the set of load thresholds. The rod reduction device according to claim 6, further configured to provide an indicator that prioritizes an increased load on a particular rod reduction device over at least one additional rod reduction device based on whether the load data from the two or more rod reduction devices meets the set of load thresholds.

9. The rod reduction device according to claim 8, wherein the set of load thresholds includes an absolute load threshold for each of the two or more rod reduction devices.

10. The rod reduction device according to claim 8, wherein the set of load thresholds includes relative load thresholds for each of the two or more rod reduction devices.

11. The rod reduction device according to claim 1, wherein the reduction feedback system includes an electronics compartment that is physically coupled to the rod reducer, and the electronics compartment includes at least one of a visual display system or a tactile display system for providing the indicator of the load data in proximity to the rod reducer.

12. The rod reduction device according to claim 11, wherein the reduction feedback system further comprises a controller coupled to the electronics compartment and coupled to a set of additional electronics compartments on an additional set of rod reduction devices in the spinal fixation system, the controller being configured to communicate with the electronics compartment and the set of additional electronics compartments via wireless or wired connection.

13. The rod reduction device according to claim 11, wherein the visual display system includes a set of lights configured to illuminate in at least two different patterns to indicate distinctions between the load data, or a display configured to provide at least two different visual indicators of the load data.

14. The rod trimming device according to claim 11, further comprising a power supply housed within the electronic equipment compartment and coupled to the visual display system or the tactile display system.

15. The rod reducing device according to claim 1, wherein the sensor is provided between the proximal end and the distal end of the rod reducing device.

16. The rod reducer according to claim 15, wherein the rod reducer comprises a multi-section shaft, and the sensor is mounted axially between different sections of the multi-section shaft.

17. The rod reshaping device according to claim 1, wherein the sensor is coupled to the proximal end of the rod reshaping device.

18. The rod reduction device according to claim 1, wherein the sensor is provided in the housing together with at least a portion of the reduction feedback system.

19. The rod reduction device according to claim 1, wherein the sensor includes at least one of a strain gauge, a pressure-sensitive film, or a capacitive sensor.

20. The rod reduction device according to claim 1, further comprising a guide assembly coupled to the pedicle screw receiver and configured to receive the rod reducer therein.

21. The rod reduction device according to claim 1, wherein the rod reduction device is configured to fully seat the spinal rod within the pedicle screw receiver, thereby enabling the spinal rod to be fixed in the pedicle screw receiver.

22. A method for operating a reduction feedback system of a rod reduction device adapted for use with a spinal fixation system, wherein the reduction feedback system has a processor, and the method for operating the system is: The processor receives load data from a sensor indicating the load applied to the spinal rod by the rod reducer of the rod reduction device while the spinal rod is seated in the pedicle screw receiver, The processor compares the load data with the load threshold of the rod restorer, The processor provides an indicator of the load data, the indicator of the load data includes an indicator of whether the load data satisfies or fails to satisfy the load threshold of the rod reducer. The processor compares the load data with additional load data detected by an additional set of sensors coupled with an additional set of rod reducers. The processor includes providing an indicator of the relative load of the rod restorer compared to at least one of the additional rod restorers in the set, The relative load indicator indicates whether the rod restorer is more loaded, less loaded, or equally loaded with respect to at least one of the additional rod restorers in the set. The operating method further includes the processor updating the relative load indicator over time as load data relating to at least one of the rod restorers or the additional rod restorers in the set is updated.

23. The operating method according to claim 22, wherein the indicator of the load data is provided by a rod straightener or by a straightening feedback system provided in an output device separate from the rod straightener.

24. The operating method according to claim 22, wherein the load data at least partially represents the amount of torque applied to the locking screw during tightening of the locking screw within the pedicle screw receiver and the compressive force applied to the rod reducer, and the indicator of whether the load data satisfies or fails to satisfy the load threshold includes an indicator of the amount by which the compressive force applied to the spinal rod should be modified to satisfy the load threshold of the rod reducer, and the load threshold is at least partially based on a model that correlates clinical data representing patient-specific bone quality with screw extraction.

25. The load threshold defines the maximum allowable load applied to the spinal rod by the rod reducer while seating the spinal rod within the pedicle screw receiver, and the maximum allowable load is a) 50 pounds (222N) to 250 pounds (1112N), b) 25 pounds (111 N) to 150 pounds (667 N), or c) The operating method according to claim 22, wherein the force is between 25 pounds (111 N) and 75 pounds (334 N).

26. The actuation method according to claim 22, wherein the spinal fixation system includes a set of rod reduction devices having a set of rod reducers engaged with the spinal rod, and the actuation method further includes the processor receiving load data indicating the load applied to the spinal rod by each rod reducer in the set.

27. The operating method according to claim 26, further comprising the processor providing an indicator of the reduction sequence of the set of rod reduction instruments based on the received load data.

28. The processor compares the load data from two or more of the rod reduction devices in the set with a set of load thresholds. The processor provides an indicator that prioritizes the increased load of a particular rod reduction device over at least one additional rod reduction device, based on whether the load data from the two or more rod reduction devices meets the set of load thresholds. The operating method according to claim 26, further comprising:

29. The operating method according to claim 28, wherein the set of load thresholds includes an absolute load threshold for each of the two or more rod reduction devices.

30. The operating method according to claim 28, wherein the set of load thresholds includes relative load thresholds for each of the two or more rod reduction devices.

31. The operating method according to claim 22, wherein the indicator for the load data includes at least one of a visual indicator or a tactile indicator provided to the operator in close proximity to the rod restorer.

32. The operating method according to claim 31, wherein the indicator for the load data includes the visual indicator, and the visual indicator includes a set of lights configured to illuminate in at least two different patterns to indicate distinctions between the load data.

33. The method of operation according to claim 22, wherein the spinal fixation system is configured such that the rod reducer is located within a guide assembly that connects to the pedicle screw receiver, and the rod reducer is configured to fully seat the spinal rod within the pedicle screw receiver, thereby enabling the spinal rod to be fixed to the pedicle screw receiver.

34. A spinal fusion monitoring system for use in spinal fusion procedures, Multiple rod reduction devices adapted for use with a spinal fixation system, wherein each of the rod reduction devices is A rod reducer having a proximal end and a distal end, wherein the distal end of the rod reducer is configured to engage with a spinal rod to seat the spinal rod within a corresponding pedicle screw receiver, A plurality of rod reduction devices, each comprising a sensor configured to detect the load applied to a portion of the spinal rod by the rod reduction device while the spinal rod is seated in the pedicle screw receiver, A reduction feedback system coupled to each of the sensors of the rod reduction device, wherein the reduction feedback system is Load data indicating the load applied to the portion of the spinal rod by each rod retractor is received from one of the corresponding sensors. The load data of each of the rod straighteners is compared with the corresponding load threshold, For each of the rod reducers, an indicator is provided indicating whether the load data satisfies or fails to satisfy the load threshold of the rod reducer, and the indicator is detectable by the operators of the plurality of rod reducers. It is configured to provide an indicator of the relative load of the first rod reducer compared to at least one additional rod reducer of the plurality of rod reducers, The relative load indicator indicates whether the first rod reducer is more, less, or equally loaded than the additional rod reducers of the plurality of rod reducers. A spinal fixation monitoring system comprising a reduction feedback system configured to update an indicator of the relative load over time as load data relating to at least one of the first rod reducer or the additional rod reducers of the plurality of rod reducers is updated.

35. The system according to claim 34, wherein the reduction feedback system comprises a housing mounted on the proximal end of each of the rod reducers to provide the indicator of the load data adjacent to each of the rod reducers.

36. The system according to claim 34, wherein the load data at least partially represents the amount of torque applied to the lock screw during tightening of the lock screw within the pedicle screw receiver and the compressive force applied to the rod reducer, and the indicator of whether the load data meets or does not meet the load threshold includes an indicator of the amount by which the compressive force applied to the spinal rod should be modified to meet the load threshold of the rod reducer, and the load threshold is at least partially based on a model that correlates clinical data representing patient-specific bone quality with screw extraction.

37. Each load threshold defines the maximum allowable load applied to the portion of the spinal rod by the rod reducer while seating the spinal rod within the pedicle screw receiver, and the maximum allowable load is a) 50 pounds (222N) to 250 pounds (1112N), b) 25 pounds (111 N) to 150 pounds (667 N), or c) The system according to claim 34, wherein the power is between 25 pounds (111 N) and 75 pounds (334 N).

38. The system according to claim 34, wherein the relative load indicator indicates the rod reducing device with the minimum load among the plurality of rod reducing devices.

39. The system according to claim 38, wherein the reduction feedback system is further configured to update the relative load indicator over time as load data for the plurality of rod reduction devices is updated.

40. The system according to claim 34, wherein the spinal fixation procedure includes a multilevel reduction procedure such that the indicator of the load data for each of the rod reduction devices includes an indicator of relative load compared to the rest of the rod reduction device engaged with the spinal rod.

41. The system according to claim 34, wherein the plurality of rod reduction devices include up to 20 rod reduction devices.

42. The system according to claim 41, wherein the reduction feedback system is further configured to provide an indicator of the reduction sequence of the plurality of rod reduction devices based on the received load data.

43. The reduction feedback system compares the load data from two or more of the rod reduction devices with a set of load thresholds. The system according to claim 42, further configured to provide an indicator that prioritizes an increased load on a rod reduction device over at least one additional rod reduction device, based on whether the load data from the two or more rod reduction devices meets the set of load thresholds.

44. The system according to claim 43, wherein the set of load thresholds includes an absolute load threshold for each of the two or more rod reduction devices.

45. The system according to claim 43, wherein the set of load thresholds includes relative load thresholds for each of the two or more rod reduction devices.

46. The system according to claim 34, wherein the reduction feedback system includes a plurality of electronic equipment compartments, each physically coupled to a corresponding rod reducer, and each electronic equipment compartment includes at least one of a visual display system or a tactile display system for providing the indicator of the load data adjacent to each rod reducer.

47. The system according to claim 46, wherein the visual display system includes a set of lights configured to illuminate in at least two different patterns to indicate distinctions between the load data.

48. The system according to claim 46, further comprising a power supply housed in the electronic equipment compartment coupled to each rod straightener, wherein the power supply is coupled to the visual display system or the tactile display system.

49. The system according to claim 46, wherein the reduction feedback system further includes a controller coupled to the plurality of electronic components on the plurality of rod reduction devices in the spinal fixation system, the controller being configured to communicate with the plurality of electronic components via wireless or wired connection.

50. The system according to claim 49, wherein the controller is housed in a centralized control module comprising a visual display and additional sensors for monitoring the spinal immobilization procedure.

51. The system according to claim 34, wherein for each of the rod reduction devices, the sensor is provided between the proximal end and the distal end of the rod reducer.

52. The system according to claim 51, wherein each of the rod reduction devices comprises a multi-section shaft, and the sensor is mounted axially between different sections of the multi-section shaft.

53. The system according to claim 34, wherein the sensor is coupled to the proximal end of each of the rod reducing devices.

54. The system according to claim 34, wherein for each of the rod reduction devices, the sensor is provided in the housing together with at least a portion of the reduction feedback system.

55. The system according to claim 34, wherein each of the rod reduction devices includes at least one of a strain gauge, a pressure-sensitive film, or a capacitive sensor.

56. The system according to claim 34, wherein each reduction instrument further comprises a guide assembly configured to connect with a corresponding pedicle screw receiver and to receive a corresponding rod reducer.

57. The system according to claim 34, wherein each of the rod reduction devices is configured such that the rod reduction device fully seates the portion of the spinal rod within the corresponding pedicle screw receiver, and the portion of the spinal rod is fixed to the corresponding pedicle screw receiver.

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