Sequential Dissection for Exposure of the Second Metatarsophalangeal Joint

Abstract

Instability of the second metatarsophalangeal (MTP) joint is relatively common, and although the anatomy of the joint has been well described and plantar plate pathology has been identified, little has been written about its exposure and repair. The goal of this study was to elucidate the necessary dissection to expose and potentially repair the lesions of the plantar plate through a dorsal approach. Sequential dorsal dissection of the second MTP joint was carried out in eight cadaveric specimens. After each step, measurements were obtained using fluoroscopic imaging and digital photography to determine the amount of exposure of the plantar plate gained by each step. Dorsal capsulotomy of the second MTP joint with collateral ligament release off of the proximal phalanx base, then combined with a subcapital oblique metatarsal osteotomy provided on average 8 and 8.5 mm of exposure of the plantar plate as measured by digital photography and fluoroscopy, respectively. Minimal exposure was gained by releasing the collateral ligaments from the metatarsal head or elevating the plantar plate off of the plantar metatarsal head. Exposure of the plantar plate can be obtained by releasing the collateral ligaments off of the proximal phalanx and performing a subcapital oblique osteotomy. Minimizing the risk of disrupting the blood supply to the metatarsal head may be possible by avoiding collateral ligament or plantar plate release.