Predictors of surgical outcomes for severe cubital tunnel syndrome: a review of 146 patients.

BACKGROUND

Full recovery is unlikely for severe cubital tunnel syndrome, and prognostic factors remain uncertain. We aimed to identify predictors of surgical outcome for these patients.

METHODS

One hundred forty-six patients with McGowan grade III cubital tunnel syndrome were evaluated retrospectively with a minimum follow-up of 2 years. All patients underwent either in situ decompression or subcutaneous transposition. The primary outcome measure was postoperative McGowan grade. Predictors included age, sex, dominant hand, disease duration, diabetes mellitus, smoking, alcohol, surgical procedure, follow-up time and preoperative electrophysiological data. Spearman's rank correlation and ordinal logistic regression model were used to assess the effect of independent variables on the postoperative McGowan grade.

RESULTS

At the last follow-up, improvement by at least one McGowan grade was reached in 118 cases (80.8%), and complete recovery was achieved in 40 hands (27.4%), while 28 extremities (19.2%) remained at grade III. Older age [per 10-year increase, odds ratio (OR) 2.10; 95% confidence interval (95% CI) 1.55-2.84, p < 0.001], longer disease duration (per 1-year increase, OR 1.31; 95% CI 1.16-1.49, p < 0.001), absent sensory nerve conduction (OR 2.55; 95% CI 1.25-5.21, p = 0.010) and shorter postoperative follow-up (per 1-year increase, OR 0.76; 95% CI 0.65-0.90, p = 0.001) were associated with a higher postoperative McGowan grade.

CONCLUSION

Significant improvement but not complete recovery could be expected following in situ decompression or subcutaneous transposition for severe cubital tunnel syndrome. Older age, longer disease duration, absent sensory nerve conduction and shorter postoperative follow-up are independent predictors of worse outcomes.