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The purpose of this study was to determine the relationship of the sural nerve to the Arthrex Percutaneous Achilles Repair System (PARS) jig and repair sutures. We performed cadaveric dissection on 10 unpaired above-knee amputation specimens (6 were right legs and 4 were left legs). In all but 1 cadaver, all of the sutures either punctured the nerve or passed anterior to it. Only 1 cadaver had sutures that were posterior to the sural nerve. In all cases, removal of the jig pulled the sutures through the nerve and the nerve was completely free after locking the sutures, and the sural nerve was within 1 cm of the lateral aspect of the transverse incision made for insertion of the jig. This cadaveric study revealed a high rate of sural nerve puncture when passing needles across the Achilles tendon using a commercially available minimally invasive repair device. This finding should caution users of Arthrex PARS jig to be attentive to postoperative symptoms of nerve injury.Level of Evidence: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Category: Ankle Introduction/Purpose: Gardner et al. (2006) reported that over 50% of operative syndesmoses are malreduced. The functional consequence of syndesmotic malreduction at two years was reported in 2012. Miller et al. in 2013, found that the 15° and 30°clamp positions caused fibula external rotation and over compression of the syndesmosis joint. The 0° medial clamp position which was in line with the trans-syndesmotic axis (TSA) did not negatively impact fibular reduction as did the other two posterior clamp positions. The purpose of this study is to identify the medial exit point of the TSA on the tibia. We hypothesized that the TSA on the medial side of the ankle would be a constant distance from the medial anterior tibial cortex. Methods: Fifty consecutive CT scans of uninjured ankles were reviewed from our image archive system. On an axial 2- dimensional reformatted image proximal to the ankle joint that included the entire incisura a line was drawn connecting the anterior and posterior limits of the incisura of the tibia. A second line was then drawn at 90 degrees at the midpoint of the first line and extended medially. Results: The average distance of the medial TSA exit point from the anterior edge of the distal medial tibia was 2.9 mm (Range 0- 9 mm, standard deviation 2.03 mm). The average anterior to posterior length of the medial distal tibia was 23.6 mm (Range 16-30, standard deviation 3.01 mm). Conclusion: Syndesmosis reduction clamp placement may first involve identifying the TSA based upon the anterior edge of the distal medial tibia. This region may be used to locate the TSA for optimal medial clamp placement. This study provides a foundation for future clamp placement investigations.

Background: Fractures of the talus are a rare but challenging injury. This study sought to quantify the area of osseous exposure afforded by a posteromedial approach to the talus and medial malleolar osteotomy. Methods: Five fresh-frozen cadaveric lower extremities were dissected using a posteromedial approach and medial malleolar osteotomy respectively. Following exposure, the talar surfaces directedly visualized were marked and captured using a calibrated digital image. The digital images were then analyzed using ImageJ software (National Institutes of Health) to calculate the surface area of the exposure. Results: The average square area of talus exposed using the posteromedial approach was 9.70 cm2 (SD = 2.20, range 7.20-12.46). The average quantity of talar exposure expressed as a percentage was 9% (SD = 1.58, range 7.03-10.40). The average square area of talus exposed using a medial malleolar osteotomy was 14.32 cm2 (SD = 2.00, range 11.26-16.66). The average quantity of talar exposure expressed as a percentage was 12.94% (SD = 1.79, range 9.97-14.73). The posteromedial approach provided superior visualization of the posterior talus, whereas the medial malleolar osteotomy offered greater access to the medial body. Conclusion: The posteromedial approach and medial malleolar osteotomy allow for significant exposure of the talus, yielding 9.70 and 14.32 cm2, respectively. Given the differing portions of the talus exposed, surgeons may prefer to use the posteromedial approach for operative fixation of posterior process fractures and elect to use a medial malleolar osteotomy in cases requiring more extensive medial and distal exposure for neck or neck/body fractures. Level of Evidence: Level IV.

Category: Bunion, Midfoot/Forefoot Introduction/Purpose: The lapidus procedure is a longstanding operation performed for the treatment of hallux valgus deformity with a concomitant hypermobile first ray. Orthopaedic surgeons have a myriad of options to choose from in performing the lapidus procedure. The implantation of orthopaedic implants comes with the risk of iatrogenic injury to surrounding anatomy. Several cadaveric studies in the humerus and femur have described potential neurovascular structures at risk during placement of intramedullary nail systems. The purpose of this study was to determine the proximity of nail insertion and interlocking mechanisms in the Lapidus Phantom Intramedullary Nail System (Paragon 28, Inc.) to neurologic and tendinous structures in the foot. Methods: A titanium intramedullary nail was inserted from the first metatarsal to the medial cuneiform spanning the first tarsometatarsal joint in 10 fresh-frozen cadaver feet. K-wires were inserted in the proximal lateral, proximal medial, and distal medial-to-lateral interlock screw paths. The tibialis anterior tendon, extensor hallucis longus tendon, and superficial peroneal nerve were carefully dissected and exposed, and the distance from each of these anatomic landmarks were then measured and recorded from four different aspects of the nail: Proximal lateral interlocking screw path, proximal medial interlocking screw path, nail insertion, distal interlocking screw path. Distances were averaged, ranges were determined. Results: The tibialis anterior tendon was in closest proximity to the proximal medial interlock K-wire with an average distance of 0.4 mm. The proximal medial interlock bisected the tibialis anterior tendon in three of the specimens. The extensor hallucis longus tendon was in closest proximity to the nail insertion with an average distance of 1.2 mm. A branch of the superficial peroneal nerve was in closest proximity to the distal interlock K-wire with an average distance of 7.5 mm, however, the nerve came in direct contact with the proximal medial interlock K-wire in two of the specimens. Conclusion: The Lapidus intramedullary nail’s proximal medial interlock screw poses the greatest threat to the tibialis anterior tendon, with the distance from the tendon to the interlock K-wire being 3 mm or less in all specimens tested. The extensor hallucis longus tendon is at risk of injury with insertion of the nail. Medial to lateral interlocking poses the greatest danger to a branch of the superficial peroneal nerve. Blunt dissection should be performed using this system with a path to bone before instrumentation to reduce the risk of nerve and tendon injury in the foot.