Revision surgery for persistent and recurrent carpal tunnel syndrome and for failed carpal tunnel release

BACKGROUND: Carpal tunnel release is one of the most frequently performed hand operations. However, persistent, recurrent, or completely new symptoms following carpal tunnel release remain a difficult problem. METHODS: A retrospective review of the surgical findings and outcomes of 50 consecutive patients who had undergone 55 revision carpal tunnel operations was performed. RESULTS: The initial carpal tunnel release was an endoscopic technique in 34 hands and an open technique in 21 hands. Thirty-four hands continued to have persistent symptoms, 18 hands had recurrent symptoms, and three hands had completely new symptoms. Reexploration revealed incomplete release in 32 patients. Circumferential fibrosis around the median nerve was found in all patients. Forty-six percent of patients with recurrent symptoms had slight palmar subluxation of the median nerve. External neurolysis was performed in 41, epineurectomy was performed in 15, synovial or hypothenar fat flap coverage was performed in eight, and radial forearm adipofascial flap coverage was performed in three hands. Symptomatic improvement following revision surgery after open carpal tunnel release was slightly better (90 percent) compared with after endoscopic carpal tunnel release (76 percent), but complete relief of symptoms following revision surgery was similar after open (57 percent) or endoscopic (56 percent) techniques. Ten patients (20 percent) showed no improvement and five patients required a third operation. CONCLUSIONS: A small number of patients (1) continue to have persistent symptoms after carpal tunnel release because of incorrect diagnosis or incomplete release of the transverse carpal ligament; (2) develop recurrent symptoms caused by circumferential fibrosis; or (3) develop completely new symptoms, which usually implies iatrogenic injury to branches of the median nerve.