Predictive value of a diagnostic block in focal nerve injury with neuropathic pain when surgery is considered.

OBJECT: In patients with focal nerve injury and neuropathic pain cutting the nerve to obtain permanent pain reduction can be considered. Surgery is indicated only if a diagnostic nerve block provides temporary pain relief. We evaluated the predictive value of a block on the outcome of surgery. METHODS: In total, three blocks were performed at two week intervals. Patients were blinded to injections containing lidocaine 1% and a placebo was included. Surgery was offered regardless of the effect of the blocks. Twenty-four patients received 72 blocks. Sixteen patients opted for surgery, 5 patients refrained from surgery, and in 3 the blocks provided permanent pain relief. The predictive ability of the block on the outcome of surgery was assessed by calculating the area under a Receiver Operating Characteristic curve (AUC). RESULTS: The AUC of the first lidocaine block was 0.35 with a 95% confidence interval from 0.077 to 0.62. At 95% confidence (two-sided), the AUC is less than 0.62, and hence the predictive ability of the block was poor. The outcome of the second lidocaine block and saline block did not change the conclusion of the first block. CONCLUSIONS: We conclude that the use of blocks to select patients for surgery should be critically appraised. PERSPECTIVE: A pain relieving response to one open block is currently considered mandatory before patients with focal nerve injury and neuropathic pain are offered surgery. Blinded blocks including a placebo show that responses for selection should be carefully interpreted because they may not be as predictive as generally presumed.

Anterior subcutaneous transposition for persistent ulnar neuropathy after neurolysis.

OBJECTIVE Little is known about optimal treatment if neurolysis for ulnar nerve entrapment at the elbow fails. The authors evaluated the clinical outcome of patients who underwent anterior subcutaneous transposition after failure of neurolysis of ulnar nerve entrapment (ASTAFNUE). METHODS A consecutive series of patients who underwent ASTAFNUE performed by a single surgeon between 2009 and 2014 was analyzed retrospectively. Preoperative and postoperative complaints in the following 3 clinical modalities were compared: pain and/or tingling, weakness, and numbness. Six-point satisfaction scores were determined on the basis of data from systematic telephonic surveys. RESULTS Twenty-six patients were included. The median age was 56 years (range 22-79 years). The median duration of complaints before ASTAFNUE was 23 months (range 8-78 months). The median interval between neurolysis and ASTAFNUE was 11 months (range 5-34 months). At presentation, 88% of the patients were experiencing pain and/or tingling, 46% had weakness, and 50% had numbness of the fourth and fifth fingers. Pain and/or tingling improved in 35%, motor function in 23%, and sensory disturbances in 19% of all the patients. Improvement in at least 1 of the 3 clinical modalities was found in 58%. However, a deterioration in 1 of the 3 modalities was noted in 46% of the patients. On the patient-satisfaction scale, 62% reported a good or excellent outcome. Patients with a good/excellent outcome were a median of 11 years younger than patients with a fair/poor outcome. No other factor was significantly related to satisfaction score. CONCLUSIONS A majority of the patients were satisfied after ASTAFNUE, even though their symptoms only partly resolved or even deteriorated. Older age is a risk factor for a poor outcome. Other factors that affect outcome might play a role, but they remain unidentified. One of these factors might be earlier surgical intervention. The modest results of ASTAFNUE should be mentioned when counseling patients after failure of neurolysis of ulnar nerve entrapment to manage their expectations. Patients, especially those who are elderly, might even consider not undergoing a secondary procedure. A randomized trial that includes a conservative treatment group and groups undergoing one of the several possible surgical procedures is needed to find the definitive answer for this clinical problem.