An outcome study for ulnar neuropathy at the elbow: a multicenter study by the surgery for ulnar nerve (SUN) study group.

BACKGROUND

Many instruments have been developed to measure upper extremity disability, but few have been applied to ulnar neuropathy at the elbow (UNE).

OBJECTIVE

We measured patient outcomes following ulnar nerve decompression to (1) identify the most appropriate outcomes tools for UNE and (2) to describe outcomes following ulnar nerve decompression.

METHODS

Thirty-nine patients from 5 centers were followed prospectively after nerve decompression. Outcomes were measured preoperatively and at 6 weeks, 3 months, 6 months, and 12 months postoperatively. Each patient completed the Michigan Hand Questionnaire (MHQ), Carpal Tunnel Questionnaire (CTQ), and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaires. Grip, key-pinch strength, Semmes-Weinstein monofilament, and 2-point discrimination were measured. Construct validity was calculated by using Spearman correlation coefficients between questionnaire scores and physical and sensory measures. Responsiveness was assessed by standardized response means.

RESULTS

Key-pinch (P = .008) and Semmes-Weinstein monofilament testing of the ulnar ring (P < .001) and small finger (radial: P = .004; ulnar: P < .001) improved following decompression. Two-point discrimination improved significantly across the radial (P = .009) and ulnar (P = .007) small finger. Improved symptoms and function were noted by the CTQ (preoperative CTQ symptom score 2.73 vs 1.90 postoperatively, P < .001), DASH (P < .001), and MHQ: function (P < .001), activities of daily living (P = .003), work (P = .006), pain (P < .001), and satisfaction (P < .001). All surveys demonstrated strong construct validity, defined by correlation with functional outcomes, but MHQ and CTQ symptom instruments demonstrated the highest responsiveness.

CONCLUSION

Patient-reported outcomes improve following ulnar nerve decompression, including pain, function, and satisfaction. The MHQ and CTQ are more responsive than the DASH for isolated UNE treated with decompression.