Surgical drills and endoscopic procedures for craniosynostosis

Abstract

A surgical drill system for use with a drill bit includes a base and a drill head disposed forward of the base operably connected to the base. The drill head includes a drill bit interface to which a shaft of the drill bit can be attached such that an axis of the shaft of the drill extends at an angle relative to a direction of the drill head at the drill bit interface. The surgical drill system further includes a drive system operably connected to the drill bit interface and configured to rotate the drill bit about the axis of the shaft of the drill bit when connected to the interface.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 321,910, filed March 21, 2022, the disclosure of which is incorporated herein by reference. [Background technology]

[0002] The following information is provided to assist the reader in understanding the technology disclosed below and the environments in which such technology may typically be used. Unless expressly defined in this document, the terms used herein are not intended to be limited to any particular narrow interpretation. References described herein may enhance the ease of understanding the technology or background. The disclosures of all references cited herein are incorporated by reference.

[0003] Craniosynostosis is a specific dysfunction of membranous bone formation, a mechanism primarily associated with the development of the skull and other flat bones. Generally, craniosynostosis is a congenital abnormality in which the bones of an infant's skull fuse prematurely. The spaces between the bones of an infant's skull are typically filled with a flexible substance called sutures. The sutures allow the skull to grow in tandem with the developing brain. In craniosynostosis, one or more sutures close prematurely, which can limit or delay smooth brain growth, cause cranial deformity, and / or contribute to increased intracranial pressure, resulting in sequelae such as neurocognitive impairment and vision loss.

[0004] Craniosynostosis is classified based on which suture or sutures fuse prematurely. The sagittal suture, for example, runs along the top of the head from the soft spot near the forehead to the back of the head in infants. Sagittal synostosis (SS), caused by premature fusion of the sagittal suture, restricts skull growth along the midline between the fontanelles, resulting in relative overgrowth of other sutures and resulting in cranial deformity due to excessive stretching of the skull relative to its width, known as scaphocephaly.

[0005] Treatment for craniosynostosis may involve surgery. Often, such surgery is performed during the first year of life. This may be an open, bone-reconstructive procedure, in which the surgeon makes a large ear-to-ear incision in the infant's scalp, or a less invasive, endoscopic procedure. For children between three and six months of age, some surgeons have recently preferred to perform minimally invasive / endoscopic strip craniotomy, with the patient wearing either a postoperative helmet or spring support. Endoscopic procedures require significantly smaller incisions, resulting in less tissue disruption, blood loss, and anesthesia time.

[0006] Unfortunately, the surgical instruments available to surgeons performing endoscopic bone surgery (e.g., endoscopic surgery for craniosynostosis, such as sagittal synostosis) are not well suited to the task, due in part to the unique trajectory of view relative to the bone being removed. Therefore, improved surgical instruments and related techniques need to be developed. Summary of the Invention

[0007] In one aspect, a surgical drill system for use with a drill bit includes a base and a drill head operably connected to the base and positioned forward of the base. The drill head includes a drill bit interface to which a shaft of the drill bit can be attached such that the axis of the shaft of the drill extends at an angle to (i.e., relative to) the direction of the drill head (i.e., the forward extension direction or the axis of the drill head) at the drill bit interface. The surgical drill system further includes a drive system operably connected to the drill bit interface and configured to rotate the drill bit about the axis of the shaft of the drill bit when connected to the interface. In some embodiments, the drive system is a mechanical drive system or a pneumatic drive system.

[0008] In some embodiments, the drill head includes a support. The drill bit interface may be disposed on the support, for example, such that the shaft of the drill extends at an angle relative to the support at the drill bit interface. The angle may be, for example, in the range of about 20° to about 100° relative to the axis of the support at the drill bit interface. In some embodiments, the angle is in the range of about 30° to about 90° relative to the axis of the support at the drill bit interface.

[0009] In some embodiments, the surgical drill system further includes a guard extending forward of the drill bit interface. The guard may be, for example, removably attached to the support or movably attached to the support. In some embodiments, the guard extends forward beyond the forward-most portion of the drill bit.

[0010] In some embodiments, the drill head is rotatable relative to the base. In some embodiments, the drill head further includes a second member extending forward and spaced apart from the support. The second member may be positioned opposite the support, for example, and the drill bit may be positioned between the support and the second member.

[0011] In some embodiments, the surgical drill system includes an extension section extending between a base and a drill head. The extension section may extend between the base and the drill head in a straight, curved, or curvilinear manner, for example. In some embodiments, the extension section extends between the base and the drill head at an angle relative to the handle.

[0012] In another aspect, a method for performing endoscopic surgery includes endoscopically inserting a surgical drill system, the surgical drill system including a base and a drill head disposed forward of and operably connected to the base. The drill head includes a drill bit interface to which a shaft of a drill bit can be attached such that the axis of the drill shaft extends at an angle to (or relative to) the direction of the drill head at the drill bit interface. The surgical drill system further includes a drive system operably connected to the drill bit interface and configured to rotate the drill bit about the axis of the drill bit shaft when connected to the interface. In some embodiments, the drive system is a mechanical drive system or a pneumatic drive system.

[0013] As noted above, in some embodiments, the drill head includes a support. The drill bit interface may be disposed on the support, for example, such that the shaft of the drill bit extends at the angle relative to the support at the location of the drill bit interface. The angle may be, for example, in the range of about 20° to about 100° relative to the axis of the support at the location of the drill bit interface, or in the range of about 30° to about 90° relative to the axis of the support at the location of the drill bit interface.

[0014] In some embodiments, the surgical drill system further includes a guard extending forward of the drill bit interface. The guard may be, for example, removably attached to the support or movably attached to the support. In some embodiments, the guard extends forward beyond the forward-most portion of the drill bit.

[0015] In some embodiments, the drill head is rotatable relative to the base. In some embodiments, the drill head further comprises a second member extending forwardly and spaced apart from the support. The second member may, for example, be positioned opposite the support, with the drill bit positioned between the support and the second member.

[0016] For example, the surgical drill system may include an extension section extending between the base and the drill head. The extension section may extend between the base and the drill head in a straight, curved, or curvilinear manner. In some embodiments, the extension section extends between the base and the drill head at an angle relative to the base.

[0017] In another aspect, a method for performing endoscopic craniosynostosis surgery on a patient comprises endoscopically inserting a surgical drill system. The surgical drill system comprises a base and a drill head operably connected to the base. A drill bit is rotatably attached to the drill head. The method further comprises removing bone via the surgical drill system. In some embodiments, the method further comprises positioning a component between the bone and underlying soft tissue during the bone removal to protect the underlying soft tissue from contact with the drill bit. The component may be, for example, part of an instrument and may be independent (or separate) from the drill system. The instrument may be, for example, a suction tube.

[0018] In some embodiments, the component is a component of the drill head. The drill head may further include, for example, a guard extending forward of the drill bit interface. In some embodiments, the guard is removably attached to the drill head. For example, the guard may extend forward beyond the forward-most portion of the drill bit.

[0019] In some embodiments, the drill head is rotatable relative to the base. In some embodiments, the drill head further comprises a second member extending forward and spaced apart from the guard. The second member may, for example, be positioned opposite the guard, with the drill bit positioned intermediate the guard and the second member.

[0020] In a further aspect, a surgical drill system for use with a drill bit includes a base and a drill head disposed forward of and operably connected to the base. The drill head includes a drill bit interface to which a shaft of the drill bit can be attached such that the axis of the shaft of the drill extends from the drill head at the drill bit interface. The drill head further includes a guard extending forward of the drill bit interface. The surgical drill system further includes a drive system operably connected to the drill bit interface configured to rotate the drill bit about the axis of the shaft of the drill bit when connected to the interface. A guard may be removably attached to the drill head, for example. In some embodiments, a guard extends forward beyond a forward-most portion of the drill bit. In some embodiments, the drill head is rotatable relative to the base.

[0021] The drill head may further comprise a second member, for example extending forward and spaced apart from the guard, the second member being, for example, positioned opposite the guard, the drill bit being positioned intermediate the guard and the second member.

[0022] In some embodiments, the axis of the drill shaft extends at an angle relative to the forward extension of the drill head at the location of the drill bit interface.

[0023] The present devices, systems, and methods, together with their attributes and attendant advantages, will be best appreciated and understood by considering the following detailed description in conjunction with the accompanying drawings (not necessarily to scale). [Brief explanation of the drawings]

[0024] [Figure 1A] An embodiment of a surgical drill commonly used in transnasal surgery, for example, is shown, with an inset showing a close-up of the drill bit. [Figure 1B] 1B illustrates a schematic representation of the surgical technique used by the inventors in performing craniosynostosis surgery using the surgical drill of FIG. 1A. [Figure 2] 1 illustrates an embodiment of a surgical drill, surgical drilling instrument, or surgical drilling system of the present invention, where the distal end or drill head of the drill system to which a rotatable drill bit is attached rotates about its axis to four different positions separated by approximately 90 degrees of rotation, and the drill bit rotates about an axis A extending at an angle α (e.g., generally perpendicular) to the direction or axis of extension of the distal end of the drill. [Figure 3A] 3 shows a schematic side view of a craniosynostosis surgery of the present invention using the surgical drill instrument of FIG. 2. [Figure 3B] 3 shows a schematic front view of a craniosynostosis surgery of the present invention using the surgical drill instrument of FIG. 2. [Figure 3C] 1 shows a side schematic view of another embodiment of the surgical drill instrument of the present invention having a generally straight extension section extending between the base or handle and the drill head; [Figure 4] 10 shows another embodiment of the surgical drill of the present invention including an upper guard and a foot or lower guard. [Figure 5A] 10 shows a top plan view of another embodiment of a surgical drill, instrument, or surgical drill system of the present invention in which the rotary drill bit is mechanically driven. [Figure 5B] 5B shows a side cross-sectional view of the surgical drill of FIG. 5A taken along section AA of FIG. 5A. [Figure 5C] 5B shows an enlarged portion of the surgical drill of FIG. 5A near the drill head indicated by box B in FIG. 5B, illustrating the drill bit interface extending at an angle relative to the direction of the drill head and its support. [Figure 5D] 5B shows an isometric view of the surgical drill of FIG. 5A. [Figure 6A]5B shows a top plan view of another embodiment of a surgical drill, instrument, or surgical drill system of the present invention, similar in function to the embodiment of FIG. 5A, in which the rotary drill bit is pneumatically driven. [Figure 6B] 6B shows a side cross-sectional view of the surgical drill of FIG. 6A taken along section AA of FIG. 6A. [Figure 6C] 6B shows an enlarged portion of the surgical drill of FIG. 6A indicated by box B in FIG. 6B. [Figure 6D] 6B shows an isometric view of the surgical drill of FIG. 6A. [Figure 7A] 10 shows a top plan view of another embodiment of the surgical drill, instrument, or surgical drill system of the present invention, in which the rotary drill bit is mechanically driven. [Figure 7B] 7B shows a side cross-sectional view of the surgical drill of FIG. 7A taken along section AA of FIG. 7A. [Figure 7C] 7B shows an enlarged portion of the surgical drill of FIG. 7A indicated by box B in FIG. 7B. [Figure 7D] 7B shows an isometric view of the surgical drill of FIG. 7A. [Figure 8A] 7B shows a top plan view of another embodiment of a surgical drill, instrument, or surgical drill system of the present invention, similar in function to the embodiment of FIG. 7A, in which the rotary drill bit is pneumatically driven. [Figure 8B] 8B shows a side cross-sectional view of the surgical drill of FIG. 8A taken along section AA of FIG. 8A. [Figure 8C] 8B shows an enlarged portion of the surgical drill of FIG. 8A indicated by box B in FIG. 8B. [Figure 8D] 8B shows an isometric view of the surgical drill of FIG. 8A. DETAILED DESCRIPTION OF THE INVENTION

[0025] It will be readily understood that the components of the present embodiments, as generally described herein and illustrated in the Figures, may be arranged and designed in a wide variety of different configurations in addition to the exemplary embodiments described. Thus, the following more detailed description of the exemplary embodiments illustrated in the Figures is not intended to limit the scope of the embodiments as claimed, but is merely an illustration of exemplary embodiments.

[0026] References throughout this specification to "one embodiment" or "an embodiment" (or the like) mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of phrases such as "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment.

[0027] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are set forth to provide a thorough understanding of the present embodiments. However, one skilled in the art will recognize that various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring them.

[0028] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to "a guard" includes a plurality of such guards and equivalents thereof known to those skilled in the art, and a reference to "the guard" is a reference to one or more such guards and equivalents thereof known to those skilled in the art, and so forth. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each separate value and intervening range is incorporated herein as if each separate value were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contraindicated by text.

[0029] As used herein, the terms "electronic circuitry," "circuitry," or "circuit" include, but are not limited to, hardware, firmware, software, or combinations of each for performing a function(s) or operation(s). For example, based on desired characteristics or needs, a circuit may comprise a software-controlled microprocessor, discrete logic such as an application-specific integrated circuit (ASIC), or other programmed logic device. A circuit may also be embodied entirely in software. As used herein, "circuit" is considered synonymous with "logic." As used herein, the term "logic" includes, but is not limited to, hardware, firmware, software, or combinations of each for performing a function(s) or operation(s) or causing a function or operation from other components. For example, based on desired application or needs, logic may comprise a software-controlled microprocessor, discrete logic such as an application-specific integrated circuit (ASIC), or other programmed logic device. Logic may also be embodied entirely in software.

[0030] As used herein, the term "processor" includes virtually any number of processor systems or stand-alone processors, such as, but not limited to, any combination of microprocessors, microcontrollers, central processing units (CPUs), and digital signal processors (DSPs). A processor may be associated with various other circuits that support the operation of the processor, such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), clocks, decoders, memory controllers, or interrupt controllers. These support circuits may be internal or external to the processor or its associated electronic packaging. The support circuits are in operative communication with the processor. The support circuits are not necessarily shown separately from the processor in a schematic diagram or other drawing.

[0031] As used herein, the term "controller" includes, but is not limited to, any circuit or device that coordinates and controls the operation of one or more input and / or output devices. A controller may comprise, for example, a device having one or more processors, microprocessors, or central processing units that can be programmed to perform functions. Generally, the term "input / output (IO) device" refers to any hardware used by a human operator / user or other system to communicate with a processor / computer. An input / output device can send data to a computer (output) and / or receive data from a computer (input). User interface input / output devices include, for example, joysticks, mice, keyboards, displays / touchscreen displays, cameras, voice recognition systems, motion control systems, etc.

[0032] As used herein, the term "software" includes, but is not limited to, one or more computer-readable or executable instructions that cause a computer or other electronic device to perform a desired function, action, or operation. The instructions may be embodied in various forms, such as routines, algorithms, modules, or programs, including applications or code apart from dynamic link libraries. Software may also be implemented in various forms, such as stand-alone programs, function calls, servlets, applets, instructions stored in memory, part of an operating system, or other types of executable instructions. Those skilled in the art will appreciate that the form of software will depend, for example, on the requirements of a desired application, the environment in which it will operate, or the desires of the designer / programmer, etc.

[0033] In a typical endoscopic procedure for the treatment / correction of sagittal synostosis, the patient is positioned prone, supine, or lateral with the head immobilized in a horseshoe frame. Ample local anesthesia with epinephrine is instilled into the scalp after abrasion with a chlorhexidine brush. Typically, the head of the bed is rotated 180° away from the anesthesia team. The scalp is thoroughly disinfected with betadine solution after the incision line is marked. A 2-3 cm incision may be made, for example, close to the midpoint between the fontanelles, allowing the majority of the endoscopic procedure to be performed in a single direction. Other surgeons choose to use a different technique, such as two separate 1 cm incisions in the skin overlying the anterior and posterior bone synostosis. The scalp is sharply incised down to the galea, and both edges are elevated with skin hooks. Local hemostasis is achieved as needed, and the pericranial membrane is bluntly separated from the galea along the intended craniotomy path. Two lines are drawn bilaterally from the midline with an electrocautery needle to define the 1-cm bone strip that is typically removed. A burr hole is drilled at the posterior edge of the incision and offset from the skull midline to avoid directly drilling the sagittal sinus. The dura is dissected from the adjacent bone with, for example, a modified Penfield 4 dissector. A bone rongeur may be used to extend the burr hole anteriorly along the separated bone. The craniotomy may be performed in an inferior direction first to prevent additional blood pooling in the surgical field from the bony edges from the higher point of the craniotomy. Skin hooks may also be used to move the scalp anteriorly, allowing for the removal of longer lengths with sequential dural dissections. If the incision is preferentially made closer to one end of the bony union than the other, as described above, or if the provider cannot easily view the video screen when oriented to best perform an inferior suture resection, the procedure may be best performed in an inferior direction, primarily with a rongeur extending to the fontanelle via scalp traction with skin hooks or lighted retractors. Using the endoscope in a retrograde direction can be disorienting unless the surgical team is repositioned to face away from the patient's torso and toward the fontanelle inferiorly. Positioning the incision in this manner avoids the inconvenience, risk of surgical site contamination, and the time cost of the procedure by requiring a relatively small amount of bone removal in the inferior direction.

[0034] An illuminated endoscope may be inserted by the co-surgeon, and after extending the dural dissection, further bone may be resected piecemeal with a small-eyed rongeur. In the inventor's experience, the use of sinus instruments significantly reduces the time cost and difficulty of distal suture resection. Once beyond the reach of the rongeur, for example, a straight Blakeslee through-cutting forceps (Karl Storz, Germany) may be used to further resect the midline bone piecemeal. If the through-cut is obstructed or otherwise insufficient, a curved Blakeslee ethmoid rongeur (Karl Storz, Germany) or a pituitary rongeur (various types known to those skilled in the art) can be used to add additional width distally to the suture resection. The dura is gradually peeled away as the suture resection is further extended.

[0035] Intermittent withdrawal of the endoscope is beneficial to better visualize the direction of advancement. In this regard, surgeons often deviate from their dominant side over time without intermittent correction. The sagittal sinus is also a good landmark for finding the midline, but visualization becomes increasingly difficult during distal endoscopic procedures due to the increased parallelism of the endoscope relative to the dura. Paradoxically, the farther one advances from the incision, the more advantageous and ergonomic drilling becomes with the long, slender, curved shaft of the drill.

[0036] In some cases, despite extending the suture resection from fontanelle to fontanelle, the parietal bone remains insufficiently mobile. In such cases, the proximal lambdoid suture may be stripped free of the dura and additional suture resections performed until mobility is satisfactory. Depending on the surgical plan, a distractor spring may be inserted at this point in the procedure. If a spring is applied, it is important to inspect the thickness of the bone along the resection. In young patients, the bone may not be strong enough to allow for spring insertion, and the surgical plan may need to be revised. The dura should also be inspected to ensure a sufficient amount of bone stripping and to prevent inadvertent damage to the dura with insertion of the spring footplate. The scalp may be closed in the standard manner with absorbable sutures.

[0037] Addressing bone thickness can be difficult with some sinus instruments. By retracting the scalp using an endoscope and the dura mater using a suction tip, the bone can be safely drilled under irrigation down to the inner cortex using, for example, a surgical drill or drill system 5 including, for example, a 4 mm coarse diamond round drill bit 10, as shown in FIG. 1A. The shaft 12 of the drill bit 10 rotates about an axis A that is collinear or coaxial with the axis A' of the distal end or drill head 22 of the drill system 5. In that regard, the shaft 12 extends from the distal end of the drill head 22 parallel or collinear to the axial direction of the drill head 22, and the drill bit 10 extends forward of other components or portions of the drill system 5. As used herein, the term "drill head" refers to the portion (typically the end) of the drill or drill system that includes the interface that connects / detachably connects the drill bit to the drive system of the drill. A short, angled drill handle 20 (such as those available from Stryker, Inc., Kalamazoo, Michigan) may be more ergonomic and allow for more distal access than a straight handle. Such drills are used, for example, in transnasal procedures. The drilling technique also helps manage bone bleeding because the coarse diamond drill bit 10 provides a cauterizing effect. Infants have limited blood volume, so limiting bleeding is desirable. Depending on the angle, a drill system 5 and / or through-cutting forceps can be used to efficiently complete the medial cortical craniotomy until the fontanelle is reached. The parietal bone may be palpated through the scalp under endoscopic visualization to confirm proper mobilization.

[0038] FIG. 1B schematically illustrates the use of a drill bit 10 of a drill system 5 in an embodiment of the endoscopic craniosynostosis surgery of the present invention. During surgery, the drill bit 10 must be lowered from above toward the bone toward the soft tissue underlying the skull, as shown in FIG. 1B. While the axial tip or end of the drill bit 10 is relatively smooth, the diamond-covered circumferential surface in the center or periphery of the drill bit 10 may cause significant damage to the soft tissue underlying the skull. As shown in FIG. 1B, an instrument 30, such as a suction tube, independent or separate from the drill system 5 may be used under the underside of the skull to protect the drill bit 10 from contacting the underlying soft tissue. In that regard, the soft tissue beneath the skull may be dissected to place, for example, a suction tube or other protective instrument, including, but not limited to, a retractor or dissector, under the skull to protect the soft tissue from the drill bit 10 (e.g., the dura and sagittal sinus).

[0039] While drill systems such as Drill System 5 have been applied by the present inventors to craniosynostosis with some notable success, the present inventors have found Drill System 5 to be ergonomically inefficient for such applications. For example, use of Drill System 5 required the development of surgical techniques of the present invention, including the use of a second instrument 30, such as the suction tube shown in FIG. 1B, that is separate or independent from Drill System 5 to protect the intracranial soft tissues (dura, brain, blood vessels) from abrasion. Furthermore, an additional instrument, such as a Penfield 4 dissector, is required to separate the bone from the dura before advancing a retraction instrument between the bone and the dura.

[0040] In some embodiments of the drill head of the drill system of the present invention, the drill bit is attachable (typically removably attached) to the drill bit interface so that the drill shaft extends at an angle relative to the forward extension direction of the drill head (as determined by the location of the drill bit interface). Components or portions of the drill head may extend in a direction or along an axis different from the axis of the drill bit shaft at the forward and drill bit shaft attachable interfaces, for example. Such components or portions may function, for example, to protect soft tissue in the vicinity of the drill bit (e.g., below the drill bit in the case of craniosynostosis surgery) or to assist in stripping the dura mater from the bone prior to drilling. Additionally, the drill bit shaft may extend at an angle from the drill bit interface of the drill head to facilitate advancement of the sharp cuttings of the drill bit toward the front of the bone during bone removal.

[0041] In that regard, FIG. 2 illustrates an embodiment of a drill system 100 of the present invention. Unlike drill system 5, in which drill bit 10 rotates about an axis that is aligned, collinear, coaxial, or parallel to the direction / axis of the distal end of drill head 22 of drill 5, drill bit 110 rotates about axis A (of its shaft 112) that is oriented at angle α (e.g., in a range of about 20° to about 110° or about 30° to about 90°) to the (forward-extending) direction of drill head 122 (e.g., of axis A′) of drill system 100 at drill bit interface 125. In the embodiment illustrated in FIG. 2, axis A is oriented approximately perpendicular or at about 90° relative to the direction of drill head 122 of drill system 100 at drill bit interface 125. As used herein with respect to any angle α, the term “approximately” refers to a direction within 10% or 5% of the stated angular degree.

[0042] In some embodiments, the drill head 122 may be rotatable about its axis such that the orientation or axis of the drill bit 110 relative to the base or handle 120 of the drilling system 100 is adjustable. In the embodiment shown in FIG. 2, the drill head 122 is rotatable relative to the extension section 140 (extending between the base or handle 120 and the drill head 122) to four positions as shown in panels a-d. The drill bit 110 shown in FIG. 2 is representative of suitable drill bits for use in connection with the drilling system 100 and other drilling systems of the present invention. For example, many types of drill bits known in the medical arts may be used in connection with the drilling systems of the present invention.

[0043] In the embodiment of FIG. 2 , the drill head 122 includes a forward-extending support 124 including a drill bit interface 125 to which the shaft 112 of the drill bit 110 is removably attached and from which the shaft 112 extends upon attachment. A drive system 130 (see panel a of FIG. 2 ), which may include, for example, an electric or pneumatic motor, is operably connected to the shaft 112 to rotate the drill bit 110 by a connection mechanism 132 (see panel a of FIG. 2 ), which may include, for example, a rotating shaft, a chain system, or a belt system. Non-parallel shafts, such as the drill bit shaft 112, and the rotational axis of the connection mechanism 132 may be operably connected, for example, via bevel gears, as known in the mechanical arts, in some embodiments. The drive system 130 may also be a pneumatic drive system. The axis A of the drill bit shaft 112 may or may not extend at an angle relative to the direction of the base or handle 120 or the axial direction (e.g., depending on the relative orientation of the drill head 122 with respect to the base or handle 120). However, the extension of the drill bit shaft 112 at an angle α relative to the direction of the drill head 122 at the drill bit interface 125 facilitates manipulation of the base or handle 120 to approach the bone at various angles while providing protection to the surrounding soft tissue.

[0044] As used herein to describe the drill system 100, the terms "axial" or "axially" (or similar terms) generally refer to one or more axes about which portions or components of the system 100 (e.g., the drill bit 110, the drill head 122, the support 124, the base or handle 120) are formed (although not necessarily symmetrically about). Such axes can be straight, curved, or bent. The terms "proximal" or "rearward" generally refer to a direction toward the base or handle 120. The terms "distal" or "forward" generally refer to a direction toward the drill head 122 / drill bit 110. The term "radial" generally refers to a direction perpendicular to an axis.

[0045] FIG. 3A shows a side schematic view of an embodiment of a craniosynostosis procedure using the surgical drilling instrument 100 of FIG. 2, while FIG. 3B shows a front schematic view of such a procedure. As shown in FIGS. 3A and 3B, the orientation of the drill bit 110 allows for advancement of the drill bit 110 into the bone at the front of the skull so that the sharp cutting edge of the drill bit 110 is oriented generally flush with the skull, while the blunt axial end of the drill bit 110 is oriented toward the soft tissue. Additionally, a support 124 may act as a guard to shield soft tissue beneath the skull from cutting and may be used to deflect soft tissue from the drill bit 110. In some embodiments, the support 124 is sufficiently wide to ensure that soft tissue is deflected or pushed aside to prevent contact with the drill bit 110. The support 124 may, for example, be at least half as wide as the diameter of the drill bit 110, or at least as wide as the diameter of the drill bit 110. The support 124 may include a forward guard section or guard 126 that extends beyond the forward boundary of the drill bit 110. The forward guard 126 may be, for example, removable or telescopically extendable / retractable to facilitate various procedures. The support 124 and forward guard section or guard 126 may be made in various widths and / or lengths to fit various sized drill bits.

[0046] The drilling instrument 100 of the present invention works well for drilling / removing bone in a variety of orientations in addition to or in addition to the bone / skull orientations shown in Figures 3A and 3B. The drilling instrument 100 of the present invention works particularly well in situations where the bones are oriented perpendicular, parallel, or at other angles between them.

[0047] In the illustrated embodiment, the extension section 140 of the drill instrument 100 extends in an angled or curved path to facilitate the direction and extension of the drill bit 110 in the plane of the skull. For relatively thick bone structures, the surgical drill instrument or system 100 may move forward or forward multiple times to completely remove a portion of bone. In other embodiments, the extension section 140 may extend in a straight or linear fashion from the base or handle 120, as shown in FIG. 3C . The extension section 140 may also extend in a curved or angled fashion from the base or handle 120. Extension sections of different lengths, as well as straight, angled, curved, curvilinear, etc., extension sections, may be interchangeable within a single drill system 100 to facilitate use of the drill system 100 in different procedures and / or by different users.

[0048] 4 illustrates another embodiment of a surgical drill, surgical drill system, or instrument 100a of the present invention. In many respects, drill system 100a is configured similarly to drill system 100, and components of drill system 100a are numbered similarly to like components of drill system 100, with the addition of the letter "a" to the reference numerals. In drill system 100a, drill head 122a includes an extension support or support 124a (from which drill bit shaft 112a extends via interface 125a) and at least a second extension member 124a' spaced from support 124a (e.g., positioned generally opposite support 124a or rotated about 180 degrees from support 124a) and oriented generally parallel to support 124a (i.e., within 10% or within 5% of parallel, or parallel). The support 124a and second extension member 124a' may include forward guards 126a and 126a' that operate similarly to the forward guard 126 of the drill system 100. The drill head 122a may be rotatable relative to the extension or stretch section 140a, for example, at the connection point 142a or elsewhere. As shown in FIGS. 2 and 4, the supports 124, 124a to which the drill bits 110, 110a are operatively connected may rotate to several positions such that the drill bits 110, 110a rotate in various planes of rotation to facilitate a particular surgical task or drilling procedure in multiple directions / orientations. In the embodiment of FIG. 4, each of the extension support 124a and second extension member 124a' may help protect and deflect soft tissue located adjacent each axial end of the drill bit 110a (extending between the extension support and second extension member 124a and 124a', respectively). As described above with respect to support 124 of drill system 100, one or both of guards 126a and 126a' may be extendable / retractable relative to support 124a and second extension member 124a', respectively, and may also be detachable from connection with drill system 100a.

[0049] 1A and 1B, the drill of the present invention reduces the likelihood of inadvertent contact of the drill bit of the present invention with surrounding / underlying soft tissue and allows for face-on, parallel drilling of the bone of interest. One or more guards on the drill of the present invention allow for simultaneous displacement of soft tissue above the bone (e.g., scalp tissue) and / or soft tissue below the bone (e.g., intracranial tissue) or aid in the separation of such soft tissue from the bone prior to displacement.

[0050] Because the shaft 112, 112a of the drill bit 110, 110a may extend at an angle from (or not parallel to) the drive shaft of the drive system 130, 130a, it may be desirable in some embodiments of the present invention to use a mechanical gear connection designed to operably connect non-parallel rotational shafts. Such gear connections include, for example, helical worm gears and bevel gears. In certain embodiments, chain-driven gears may be used to connect the drive shaft drive system 130, 130a to the shaft or shaft 112, 112a of the drill bit 110, 110a. Those skilled in the mechanical arts can readily design a system for driving and controlling the rotation of the drill bit of the present invention based on surgical requirements and engineering principles. In other embodiments, pneumatic power may be used to drive the shaft 112, 112a of the drill bit 110, 110a.

[0051] 5A-5D illustrate another embodiment of a surgical drilling instrument or surgical drilling system 100b of the present invention in which the rotary drill bit is mechanically driven. In many respects, drilling system 100b is configured similarly to drilling system 100a, and components of drilling system 100a are numbered similarly to similar components of drilling system 100a, with the addition of the letter "b" to the reference numerals. In the embodiment of FIGS. 5A-5D, extension section 140b extends in a generally linear direction from connector 150b, which is operably connected to base or handle 120b. Connector 150b is oriented at an angle relative to base or handle 120b. Support 124b of drill head 122b extends along the same direction as extension section 140b and may simply be considered its distal end section. In the drilling system 100b embodiment, shaft 112b of drill bit 110b extends perpendicular or perpendicular to the direction of support 124b at interface 125b. 5C, the mechanical drive system may include a drive shaft 132b (which may be flexible) operatively connected to a gear system including a first gear 134b that rotates about the axis of the drive shaft 132b. A second gear 134b' is driven by the first gear 134b and rotates about an axis perpendicular to the axis of the drive shaft 132b and the first gear 134b (collinear with the axis of the drill bit shaft 112b).

[0052] 6A-6D illustrate another embodiment of a surgical drilling instrument or surgical drilling system 100c of the present invention, in which a rotary drill bit is pneumatically driven. In many respects, drilling system 100c is configured similarly to drilling system 100b, and components of drilling system 100c are numbered similarly to similar components of drilling system 100b, with the addition of the letter "c" in the reference numerals. In the embodiment of FIGS. 6A-6D, extension section 140c extends in a curved or curvilinear direction from connector 150c, which is operably connected to base or handle 120c. Connector 150c is oriented collinearly or coaxially relative to base or handle 120c. Extension section 140c extends in a curved or curvilinear direction from connector 150c. Support 124b of drill head 122b extends in a generally linear or curvilinear direction at the distal end of extension section 140c. In an embodiment of drill system 100c, shaft 112c of drill bit 110c extends vertically or perpendicularly to support 124c at interface 125c. Drill bit shaft 112c is positioned and oriented relative to base or handle 120c much similar to the position and orientation of drill bit shaft 112b relative to base or handle 120b. For example, as shown in FIG. 6C, the pneumatic drive system includes pneumatically driven rotor 136c (e.g., including rotor blades) operably connected to a source of pressurized gas / air to rotate drill bit 110c about the axis of shaft 112c.

[0053] 7A-7D illustrate another embodiment of a surgical drilling instrument or surgical drilling system 100d of the present invention in which the rotary drill bit is mechanically driven. In many respects, drilling system 100d is configured similarly to drilling system 100b, and components of drilling system 100d are numbered similarly to similar components of drilling system 100, with the addition of the letter "d" in the reference numerals. In the embodiment of FIGS. 7A-7D, extension section 140d extends in a generally linear direction from connector 150d, which is operably connected to base or handle 120d. Connector 150d is oriented at an angle relative to base or handle 120d.

[0054] The support 124d of the drill head 122d extends at an angle relative to the direction of the extension section 140d. The shaft 112d of the drill bit 110d extends approximately vertically or perpendicularly to the support 124d at the interface 125d. For example, as shown in FIG. 7C, the mechanical drive system includes a flexible drive shaft 132d operably connected to a first gear system including a first gear 134d that rotates about the axis of the drive shaft 132d. A second gear 134d' is driven by the first gear 134d and rotates about an axis angular to the first gear 134d. The second gear 134d' drives a second drive shaft 132d' that passes through the support 124d and terminates at a third gear 136d. The third gear 136d drives a fourth gear 136d', which rotates the drill bit shaft 112d about its axis. A forward guard section or guard 126d extends at an angle relative to the direction of support 124d.

[0055] 8A-8D illustrate another embodiment of a surgical drilling instrument or surgical drilling system 100e of the present invention, in which a rotary drill bit is pneumatically driven. In many respects, drilling system 100e is configured similarly to drilling system 100c, and components of drilling system 100e are numbered similarly to similar components of drilling system 100c, with the addition of the letter "e" in the reference numerals. In the embodiment of FIGS. 8A-8D, extension section 140e extends in a curved or curvilinear direction from connector 150e, which is operably connected to base or handle 120e. Connector 150e is oriented collinearly or coaxially relative to base or handle 120e. Support 124e of drill head 122e extends in a generally linear or curvilinear direction at the distal end of extension section 140e. In the embodiment of drill system 100e, shaft 112e of drill bit 110e extends at an angle (but not perpendicular or orthogonal) to the direction of support 124e at interface 125e. With respect to base or handle 120e, drill bit shaft 112e is positioned and oriented very similarly to the position and orientation of drill bit shaft 112d with respect to base or handle 120d. For example, as shown in FIG. 8C , the pneumatic drive system may include pneumatically driven rotor 136e (e.g., including rotor blades) operably connected to a source of pressurized gas / air to rotate drill bit 110e about the axis of shaft 112e. Generally, as shown in the comparison of the embodiments of drill systems 110d and 110e, the use of a pneumatic drive may simplify the orientation of drill bits of the present invention at various angles with respect to the support member and base / handle of the present invention.

[0056] Because sagittal synostosis is the most common type of bone synostosis surgically corrected, the above surgical description focuses on sagittal synostosis as a representative example. However, the drilling system of the present invention may be equally or even more useful in less common synostosis, where the skull naturally thickens due to the proximity of other sutures to the skull base. For example, the drilling system of the present invention may be particularly useful for use at the nasofrontal junction in frontal synostosis or for drilling the greater ala of the sphenoid bone in craniosynostosis. Furthermore, the drilling system of the present invention may be used in procedures other than craniosynostosis. For example, in a representative transnasal procedure, the drilling system of the present invention may be used to rapidly drill a hole in the sphenoid rostrum. Representative examples of procedures in which the drilling system of the present invention may be used include, but are not limited to, procedures involving the sphenoid rostrum and sphenoid plane, the pterygoid bone, the medial orbital wall, the maxilla, the maxillary ridge, and maxillary wall, the hard palate, the anterior skull base, the middle skull base, and the clivus / ventral portion of the posterior fossa. Such procedures may benefit from the ability to remove or extend / retract soft tissue guards, such as guards 126, 126a, 126a', 126b, 126c, 126d, and / or 126e of the present invention. Generally, the drill system of the present invention may be used in any procedure in which it is desirable to drill a hole head-on into a target bone.

[0057] The surgical drill system of the present invention may be operated, at least in part, under computer control. FIG. 8D schematically illustrates, for example, an electronic circuit 200 operatively connected to the surgical drill system 100e. The electronic circuit 200 includes a processor system 210 (e.g., including one or more processors / microprocessors) communicatively coupled to a memory system 220. One or more algorithms may be stored in the memory system 220 executable via the processor system 210 for control of the surgical drill 100e. The electronic circuit may further include, for example, a user interface system 230 communicatively coupled to the processor system 210, a communication system operatively coupled to the processor system 210, and a sensor system 250 operatively coupled to the processor system. One or more sensors of the sensor system 250 may be used, for example, in a feedback control loop. A power system 260 may be provided with the power electronic circuit 200. The surgical system of the present invention may be used under manual or computer-assisted manual operation, or may be incorporated into a robotic system. Base 120e (or other bases of the present invention) may be, for example, a component of or operably connected to a robotic arm. Optional attachments may be provided to enable the use of such attachments as navigation tools when used in conjunction with an imaging guidance computer, as is known in the surgical arts.

[0058] The foregoing description and accompanying drawings illustrate some presently representative embodiments. Various modifications, additions, and alternative designs will naturally become apparent to those skilled in the art in view of the above teachings without departing from the scope of the invention, which is indicated by the following claims rather than by the foregoing description. All changes and variations that come within the meaning and range of equivalency of the claims are intended to be embraced within their scope.

Claims

1. 1. A surgical drill system for use with a drill bit, comprising: A base and a drill head disposed forward of the base and operably connected to the base, the drill head including a drill bit interface to which the shaft of the drill bit can be attached such that an axis of the shaft of the drill bit extends at an angle relative to a direction of the drill head at a drill bit interface; a drive system operably connected to the drill bit interface configured to rotate the drill bit about the axis of the shaft of the drill bit when connected to the drill bit interface.

2. 2. The surgical drill system of claim 1, wherein the drill head includes a support, and the drill bit interface is disposed on the support such that the shaft of the drill bit extends at the angle relative to the support at the location of the drill bit interface.

3. 3. The surgical drill system of claim 2, wherein the angle is in the range of about 20° to about 100° relative to an axis of the support at the location of the drill bit interface, or in the range of about 30° to about 90° relative to the axis of the support at the location of the drill bit interface.

4. The surgical drill system of claim 2 , further comprising a guard extending forward of the drill bit interface.

5. The surgical drill system of claim 4 , wherein the guard is removably attached to the support or movably attached to the support.

6. The surgical drill system of claim 4 , wherein the guard extends forward beyond a forward most portion of the drill bit.

7. The surgical drill system of claim 1 , wherein the drill head is rotatable relative to the base.

8. The surgical drill system of claim 2 , wherein the drill head further comprises a second member extending forwardly and spaced from the support.

9. The surgical drill system of claim 8 , wherein the second member is disposed opposite the support, and the drill bit is disposed between the support and the second member.

10. The surgical drill system of claim 1 , further comprising an extension section extending between the base and the drill head.

11. The surgical drill system of claim 10 , wherein the extension section extends between the base and the drill head in a straight, curved, or curvilinear manner.

12. The surgical drill system of claim 10 , wherein the extension section extends between the base and the drill head at an angle relative to the base.

13. The surgical drill system of claim 1 , wherein the drive system is a mechanical drive system or a pneumatic drive system.

14. 1. A method of performing endoscopic surgery, comprising: endoscopically inserting a surgical drill system, the surgical drill system comprising: A base and a drill head disposed forward of the base and operably connected to the base, the drill head including a drill bit interface to which a shaft of a drill bit can be attached such that an axis of the shaft of the drill bit extends at an angle relative to a direction of the drill head at a drill bit interface; endoscopically inserting the surgical drill system, the drive system being operatively connected to the drill bit interface and configured to rotate the drill bit about the axis of the shaft of the drill bit when connected to the interface; and advancing the drill bit in a generally forward direction into bone.

15. 15. The method of claim 14, wherein the drill head comprises a support, and the drill bit interface is disposed on the support such that the shaft of the drill bit extends at the angle relative to the support at the location of the drill bit interface.

16. 16. The method of claim 15, wherein the angle is in the range of about 20° to about 100° relative to the axis of the support at the location of the drill bit interface, or in the range of about 30° to about 90° relative to the axis of the support at the location of the drill bit interface.

17. The method of claim 15 , wherein the drill head further comprises a guard extending forward of the drill bit interface.

18. The method of claim 17, wherein the protector is removably attached to the support or movably attached to the support.

19. 18. The method of claim 17, wherein the guard extends forward beyond a forward most portion of the drill bit.

20. 20. The method of any one of claims 14 to 19, wherein the drill head is rotatable relative to the base.

21. 20. The method of any one of claims 15 to 19, wherein the drill head further comprises a second member extending forwardly and spaced apart from the support.

22. 22. The method of claim 21, wherein the second member is disposed opposite the support and the drill bit is disposed between the support and the second member.

23. 20. The method of any one of claims 14 to 19, wherein the surgical drill system further comprises an extension section extending between the base and the drill head.

24. 24. The method of claim 23, wherein the extension section extends between the base and the drill head in a straight, curved, or curvilinear manner.

25. 24. The method of claim 23, wherein the extension section extends between the base and the drill head at an angle relative to the base.

26. 20. The method of any one of claims 14 to 19, wherein the drive system is a mechanical drive system or a pneumatic drive system.

27. 20. The method of any one of claims 14 to 19, wherein the endoscopic procedure is a craniosynostosis procedure and the bone is a portion of the skull or a transnasal procedure.

28. 28. The method of claim 27, wherein the endoscopic procedure is a sagittal suture fusion procedure.

29. 20. The method of any one of claims 14 to 19, wherein the base is attached to a robotic arm of a robot operated under computer control.

30. 1. A method of performing endoscopic craniosynostosis surgery on a patient, comprising: endoscopically inserting a surgical drill system, the surgical drill system comprising a base and a drill head operably connected to the base, the drill head having a drill bit rotatably mounted thereto; removing bone via the surgical drill system.

31. 31. The method of claim 30, further comprising placing a component between the bone and underlying soft tissue to protect the underlying soft tissue from contact with the drill bit during bone removal.

32. The method of claim 31 , wherein the component is part of an implement and is separate from the drilling system.

33. 32. The method of claim 31, wherein the instrument is a suction tube.

34. The method of claim 31 , wherein the component is a component of the drill head.

35. 35. The method of claim 34, wherein the drill head further comprises a guard extending forward of the drill bit interface.

36. 36. The method of claim 35, wherein the guard is removably attached to the drill head.

37. 36. The method of claim 35, wherein the guard extends forwardly beyond a forward-most portion of the drill bit.

38. 38. The method of any one of claims 34 to 37, wherein the drill head is rotatable relative to the base.

39. 38. The method of any one of claims 34 to 37, wherein the drill head further comprises a second member extending forwardly and spaced from the guard.

40. 40. The method of claim 39, wherein the second member is disposed opposite the guard and the drill bit is disposed intermediate the guard and the second member.

41. 1. A surgical drill system for use with a drill bit, comprising: A base and a drill head disposed forward of the base and operably connected to the base, the drill head including a drill bit interface to which a shaft of the drill bit can be attached such that an axis of the shaft of the drill bit extends from the drill head at a drill bit interface, the drill head further including a guard extending forward of the drill bit interface; a drive system operably connected to the drill bit interface configured to rotate the drill bit about the axis of the shaft of the drill bit when connected to the interface.

42. 42. The surgical drill system of claim 41, wherein the guard is removably attached to the drill head.

43. 42. The surgical drill system of claim 41, wherein the guard extends forwardly beyond a forward most portion of the drill bit.

44. 44. The surgical drill system of any one of claims 41 to 43, wherein the drill head is rotatable relative to the base.

45. 44. The surgical drill system of any one of claims 41 to 43, wherein the drill head further comprises a second member extending forwardly and spaced apart from the guard.

46. 46. ​​The surgical drilling system of claim 45, wherein the second member is disposed opposite the guard and the drill bit is disposed intermediate the guard and the second member.

47. 44. The surgical drill system of any one of claims 41 to 43, wherein the axis of the shaft of the drill bit extends at an angle relative to a forward extension direction of the drill head at the location of the drill bit interface.

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