Risk of sural nerve injury with intramedullary screw fixation of fifth metatarsal fractures: a cadaver study.

The risk of injury to the sural nerve and its branches during operative procedures performed on the lateral foot and ankle is well recognized; however, there have been no anatomic studies demonstrating the proximity of the sural nerve branches to the head of an intramedullary screw used for fixation of fractures of the proximal fifth metatarsal. Dissection of 10 cadaver specimens, after insertion of 4.5-mm screws, demonstrated that the screw head was within 2 mm of the dorsolateral branch of the sural nerve in five specimens and within 3 mm of eight specimens. Irritation of or injury to the nerve during screw insertion may explain the persistence of pain after screw removal in some patients. Furthermore, patients could sustain injury to the sural nerve at the time of screw removal. Careful surgical technique, including the use of drill guides and tissue protectors, may help lessen the risk of sural nerve injury and subsequent neuroma formation.