Ulnar neuropathy at the elbow: predictive value of clinical and electrophysiological measurements for surgical outcome.

The aim of this study was to identify factors predictive of complete relief of symptoms in subjects with ulnar neuropathy at the elbow (UNE), undergoing surgical release. Clinical and electrophysiological results of 19 consecutive cases of UNE belonging to 18 patients (mean age 50.6 years, range 28-73) undergoing simple decompression were reviewed retrospectively. After surgery, seven cases were free of symptoms, nine showed improvement and three were unchanged. In all cases there was significant postoperative improvement of almost all nerve conduction values. Only preoperative sensory action potential amplitude of the ulnar nerve stimulating the little finger ( U5 SAP) was predictive of postoperative symptom free outcome. The other electrophysiological measures, age of patients, sex, presencelabsence of carpal tunnel syndrome, preoperative clinical stage and duration of symptoms were not predictive of excellent outcome. Preoperative U5 SAP amplitude was found to be a good predictor of disappearance of symptoms after UNE surgery. The probability of normalising electrophysiological values after surgery (U5 SAP amplitude, motor conduction velocity difference between across elbow and below elbow to wrist segments) depended on their preoperative values. Only the moderately anomalous values returned in the normal range.