Incidence, management, and prognosis of early ulnar nerve dysfunction in type C fractures of distal humerus.

BACKGROUND: Displaced comminuted of the distal humerus in adults are among the most complex fractures to be managed effectively. The ulnar nerve is at high risk of impingement secondary to injury, operation, and postoperative rehabilitation in these fractures. In this study we focus on the incidence, management, and prognosis of early ulnar nerve dysfunction in the course of treating type C fractures of distal humerus.

METHODS: We examine a patient sample of 117 consecutive AO type C fractures of distal humerus, between June 1998 and October 2005. Twenty-nine patients exhibited preoperative ulnar nerve compression symptoms (incidence 24.8%) and were divided into two groups randomly, which received treatment of anterior subfascial transposition or in situ decompression of the ulnar nerve respectively, in conjunction with internal fixation with medial and lateral plates.

RESULTS: The subgroup of 88 patients without preoperative ulnar nerve symptoms remained asymptomatic postoperatively (0% incidence of late ulnar nerve dysfunction). According to Bishop rating system, excellent and good results of ulnar nerve function were achieved in 13 of 15 patients (86.7%) in the transposition group, 8 of 14 patients (57.1%) in the in situ decompression group. The results difference is statistically significant (p < 0.05).

CONCLUSIONS: We conclude that neurolysis and anterior subfascial transposition of vascularized ulnar nerve during open reduction and internal fixation of type C fractures of the distal humerus is beneficial in cases of early ulnat nerve dysfunction.