Revision carpal tunnel surgery: a 10-year review of intraoperative findings and outcomes.

PURPOSE: To evaluate intraoperative findings and outcomes of revision carpal tunnel release (CTR) and to identify predictors of pain outcomes.

METHODS

We performed a retrospective cohort study of all adult patients undergoing revision CTR between 2001 and 2012. Patients were classified according to whether they presented with persistent, recurrent, or new symptoms. We compared study groups by baseline characteristics, intraoperative findings, and outcomes (strength and pain). Within each group, we analyzed changes in postoperative pinch strength, grip strength, and pain from baseline. Predictors of postoperative average pain were examined using both multivariable linear regression analyses and univariable logistic regression to calculate odds ratios of worsened or no change in pain.

RESULTS

We performed revision CTR in 97 extremities (87 patients). Symptoms were classified as persistent in 42 hands, recurrent in 19, and new in 36. The recurrent group demonstrated more diabetes and a longer interval from primary CTR, and was less likely to present with pain. Incomplete release of the flexor retinaculum and scarring of the median nerve were common intraoperative findings over all. Nerve injury was more common in the new group. Postoperative pinch strength, grip strength, and pain significantly improved from baseline in all groups, apart from strength measures in the recurrent group. Persistent symptoms and more than 1 prior CTR had higher odds of not changing or worsening postoperative pain. Higher preoperative pain, use of pain medication, and workers' compensation were significant predictors of higher postoperative average pain.

CONCLUSIONS

Carpal tunnel release may not always be entirely successful. Most patients improve after revision CTR, but a methodical approach to diagnosis and adherence to safe surgical principles are likely to improve outcomes. Symptom classification, number of prior CTRs, baseline pain, pain medications, and workers' compensation status are important predictors of pain outcomes in this population.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.