Evaluation of Anatomic Relationship between Sural Nerve and Instrumentation during Mini-open Achilles Tendon Repair: A Cadaveric Study

CATEGORY: Sports INTRODUCTION/PURPOSE: The Achilles tendon is one of the most commonly ruptured tendons in the adult population, and there is still no consensus on optimal treatment. While surgical repair may result in a lower re-rupture rate and quicker functional return, it also comes with risk of wound complications and sural nerve injury. If surgical repair is chosen, the surgeon may choose a traditional open procedure, a mini-open technique, or a percutaneous approach. The main advantage of the mini open repair method is the reduced wound complications that comes with a much smaller incision, while still maintaining similar re-rupture rates. The purpose of this study was to determine the relationship of the sural nerve to the Arthrex PARS jig and repair sutures. METHODS: Cadaveric dissection was performed on 10 unpaired above knee amputation specimens. After severing the Achilles tendon and inserting the jig for a mini open repair, the sural nerve was dissected out to determine the rate of nerve puncture by the passed sutures. The jig was then removed to determine if the nerve was bound by the passing sutures or wrapped during suture locking. RESULTS: The sural nerve was punctured 9 times out of the total of 50 sutures passed for an 18% puncture rate. All 9 punctures occurred in 4 specimens (Image 1), with the remaining 6 cadavers sustaining no punctures. Of the 6 unpunctured cadavers, 5 had all sutures passing anterior to the sural nerve, but in close proximity. One cadaver had all sutures passing posterior to the sural nerve. In all cadavers, removal of the jig and locking of the sutures left the sural nerve free with the sutures well fixed within the Achilles tendon. The sural nerve was also found to be within 1 cm of the lateral edge of the mini-open transverse incision in all cadavers. CONCLUSION: The Arthrex PARS jig was successful in preventing binding of the sural nerve during mini-open Achilles repair, but the sutures are often passed directly through the nerve during the procedure. The sural nerve is also at risk at the lateral edge of the mini-open incision used to insert the jig, and must be carefully protected during dissection down to the tendon.