Patent ID: 12251116

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The method of performing bunion surgery disclosed herein boasts a variety of inventive features and components that warrant patent protection, both individually and in combination.

FIGS.1-2Cillustrate aspects of a typical bunion correction surgery, as commonly performed using prior art techniques. By way of example only,FIGS.1-2Cillustrate an example of a foot10with a bunion growth in the metatarsophalangeal (MTP) joint12of the big toe14. At this point in the procedure, the affected metatarsal bone16has been cut18, and the metatarsal head20has been medially translated and fixed in proper alignment using one or more fixation members (not shown), for example a fixation member as shown and described in commonly owned U.S. patent application Ser. No. 16/571,042, filed on Sep. 13, 2019 and entitled “Orthopedic Bone Screw” (now issued as U.S. Pat. No. 11,045,239), which is hereby incorporated by reference as if set forth fully herein.

Typical minimally invasive bunion surgery is performed through two tiny incisions using specialized instruments. A first or distal incision22is typically made at or near the site of the bunion (e.g., metatarsal head20), and provides an access portal for cutting and realigning the bone. A second or proximal incision24is typically made near the proximal end of the affected metatarsal bone16, providing an insertion trajectory for one or more fixation members once the bone has been cut and realigned, and for a rotary bur26that is typically used to shave or remove the prominent redundant bone28. In current practice, both the distal incision22and the proximal incision24are linear horizontal incisions in that they are generally parallel to the longitudinal axis of the foot. The prominent redundant bone28that needs to be removed after the bone is realigned is located between the two incisions but nearer to the distal portion of the affected metatarsal bone. A rotary bur26spinning at high speeds is typically used during minimally invasive bunion surgery because it can be inserted through the small incisions. Current practice is to insert the bur26through the proximal incision24.

A major nerve called the medial dorsal cutaneous nerve30(referred to herein as “MDC nerve30”) provides sensation to the inside of the foot and the big toe, and is typically located just above the distal and proximal incisions22,24. Current practice is to insert the rotary bur26through the proximal incision24, approaching the prominent redundant bone28from a direction that is below and generally parallel to the MDC nerve30, as shown by way of example inFIGS.2A-2B. However, this current practice may provide a significant risk of injury to the MDC nerve30. As the high-speed bur26spins to cut the overhanging prominent redundant bone28, a back-and-forth sweeping motion is also performed to ensure the bur26can contact the entire surface area of the bone to be removed. The MDC nerve30is in close proximity with the entire shaft of the spinning rotary bur26during this motion, due to the generally parallel positioning of the bur26relative to the MDC nerve30. Thus, there may be a relatively significant possibility of the bur26becoming entangled with the MDC nerve30, which may cause the nerve to sever or tear.

As illustrated by way of example only inFIG.2C, efforts to remove the prominent redundant bone by inserting the bur26through the linear horizontal distal incision22at the metatarsal neck may cause burn damage or other wound damage to the patient's skin. This so-called “zone of destruction”32occurs when employing a sweeping motion on a rotary bur inserted transverse to the direction or angle of the incision22.

Thus, as illustrated by way of example only inFIGS.3-8, in some embodiments of the method of performing bunion surgery disclosed herein, the distal incision22may be formed at an oblique angle relative to the longitudinal axis of the foot to enable insertion of the bur26through the incision22at the same or similar angle at which the incision is made. In some embodiments, the oblique angle may be approximately 45° from proximal plantar to distal dorsal. In some embodiments, the oblique angle may be greater than 45° from proximal plantar to distal dorsal. In some embodiments, the oblique angle may be less than 45° from proximal plantar to distal dorsal. In some embodiments, the oblique angle may be within a range from 40° to 50° from proximal plantar to distal dorsal. In some embodiments, the oblique angle may be within a range from 35° to 55° from proximal plantar to distal dorsal. In some embodiments, the oblique angle may be within a range from 30° to 60° from proximal plantar to distal dorsal. In some embodiments, the oblique angle may be within a range from 25° to 65° from proximal plantar to distal dorsal.

As illustrated by way of example only inFIGS.4-6, inserting the bur26through an oblique distal incision22decreases the risk of contacting the MDC nerve30either during insertion or during the sweeping motion of the burr26during resection of the prominent redundant bone28. The oblique incision22allows the bur26to be placed higher on the foot, which prevents the surrounding skin from being shredded or burned by the bur26during the sweeping motion.

FIG.9is a flowchart describing the various steps of one example of a method50of performing bunion surgery using the novel approach to the prominent redundant bone, disclosed herein according to some embodiments. In some embodiments, the first step52of the method50is to form a pair of incisions in the patient's skin to enable access to the surgical target site (e.g., bunion). In some embodiments, one of the incisions comprises a distal incision22located near the surgical target site (e.g., at the metatarsal head20). In some embodiments, the distal incision22is formed at an oblique angle relative to a longitudinal axis of the foot10. In some embodiments, one of the incisions comprises a proximal incision24. In some embodiments, the proximal incision24may be formed parallel to a longitudinal axis of the foot10.

In some embodiments, the next step54of the method50comprises cutting the affected metatarsal bone16and then medially translating the metatarsal head20into proper alignment. In some embodiments, the instrument used to sever the metatarsal bone16may be advanced to the target site through the distal incision22.

In some embodiments, the next step56of the method50is to secure the realigned bone in place using one or more fixation elements. In some embodiments, the one or more fixation elements may be advanced to the target site through the proximal incision24. In some embodiments, the one or more fixation elements may be advanced to the target site through the proximal incision24, distal incision22, ancillary incisions, and/or percutaneous incisions.

In some embodiments, the next step58of the method50is to cut and remove the overhanging prominent redundant bone28by advancing a rotary bur26through the distal incision22so that the rotary bur26contacts the target prominent redundant bone28, and then maneuvering the bur26in a sweeping motion against the target prominent redundant bone28to remove a desired portion thereof. In some embodiments, the cut or shaved portion(s) of the prominent redundant bone28may be removed from the target site through the distal incision22.

In some embodiments, once the realigned bone has been secured with a fixation element and the target prominent redundant bone28has been removed, the last step60of the method50is to close the incisions22,24.

As illustrated by way of example only inFIG.10, in some embodiments of the method of performing bunion surgery disclosed herein, a distal incision34in the form of a wedge or ellipse incision may be formed (in lieu of the linear oblique distal incision22described above) at an oblique angle relative to the longitudinal axis of the foot to (1) enable insertion of the bur26through the incision22at the same or similar angle at which the incision is made, and (2) create a skin flap or void that may be pulled and secured in various directions to enable additional correction of the big toe14position (e.g., both adduction or toward the body's midline, and valgus or away from the body's midline) of the bunion deformity. In some embodiments, the big toe14position may be corrected using one or more additional skin flaps created near the distal incision22or distal incision34.

By way of example only,FIGS.11A-13Cillustrate an example method of correcting big toe deformity by using an elliptical or wedge-shaped incision34described above, according to some embodiments. For example,FIGS.11A-11Cillustrate top, side, and front views of an example patient's foot10having a big toe14deformity due to a bunion. Similar to the illustration ofFIG.10, an elliptical or wedge-shaped incision34has been made at an oblique angle relative to the longitudinal axis of the foot near the distal end of the metatarsal bone16. In some embodiments, the incision34may comprise a complete removal of a patch of skin. In some embodiments, the incision34may leave at least a portion of a flap of skin. After performing the bunion correction procedure described above, the big toe14positioning may be corrected by pulling on a distal edge of the elliptical incision34or flap portion in a generally proximal oblique direction (e.g., transverse to the angle of the incision). In some embodiments, this may result in big toe repositioning in multiple planes. In some embodiments, this may result in a triplanar repositioning of the big toe14, as illustrated inFIGS.12A-12C. In some embodiments, the big toe14may be corrected in a single plane. For example, as illustrated inFIGS.12A-12B, pulling on the distal incision34may cause the big toe14to be repositioned laterally outward (e.g. away from the midline of the foot) and obliquely backward. As illustrated inFIG.12C, pulling on the distal incision34may cause the big toe14to be repositioned rotationally counterclockwise (e.g., for a right foot) or rotationally clockwise (e.g., for a left foot) depending on the foot being treated. Once the big toe14has been realigned, the incision34may be closed, as illustrated by way of example only inFIGS.13A-13C.