Ulnar neuropathy at the elbow: follow-up and prognostic factors determining outcome.

OBJECTIVE: To determine the outcome in patients with ulnar neuropathy at the elbow (UNE) treated surgically or conservatively, and the prognostic value of clinical, sonographic, and electrophysiologic features.

METHODS: After a median follow-up of 14 months, 69 of 84 patients initially included in a prospective blinded study on the diagnostic value of sonography in UNE were re-evaluated. The patients underwent renewed systematic clinical and sonographic examination. Patients were scored as having a poor (stable or progressive symptoms) or favorable (complete remission of symptoms or improvement) outcome.

RESULTS: Of the 74 initially affected arms, 12 (16%) had a complete remission, 21 (28%) improved, 25 (34%) remained stable, and 16 (22%) had progression. Surgically treated patients (28 arms) had a more favorable outcome than those treated conservatively (p = 0.03). After surgery, the mean ulnar nerve diameter decreased from 3.2 to 2.9 mm (p = 0.03), while this was not seen after conservative treatment. Multiple logistic regression analysis showed that more outspoken nerve enlargement found during sonography at the time of the diagnosis was associated with a poor outcome (OR: 2.9, p = 0.009). Furthermore, the presence of a motor conduction block (OR: 0.2, p = 0.03) and motor velocity slowing across the elbow (OR: 0.1, p = 0.01) were associated with a favorable outcome.

CONCLUSION: More pronounced ulnar nerve thickening at the time of the diagnosis is associated with poor outcome at follow-up, especially in conservatively treated cases, while electrodiagnostic signs of demyelination on testing indicate favorable outcome.