Perioperative ulnar neuropathy in orthopaedics: association with tilting the patient.

The incidence and causes of perioperative ulnar neuropathy in a prospective series of 203 consecutive patients were examined. Three percent of patients had ulnar neuropathy develop in the entire prospective series. The incidence was 6% in patients having total hip arthroplasty. There was a highly significant association between a tilted body position on the operating table and development of ulnar neuropathy on the contralateral side. This position rotates the arm internally and places the ulnar nerve at risk for direct compression.