Canaletto implant in revision surgery for carpal tunnel syndrome: 21 case series.

Revision carpal tunnel surgery varies from 0.3% to 19%. It involves a delayed neurolysis and prevention of perineural fibrosis. Despite numerous available procedures, the results remain mediocre. The aim of this study is to evaluate the results of the Canaletto implant in this indication. Our series includes 20 patients (1 bilateral affection) reoperated for carpal tunnel between October 2008 and December 2009. After the first operation, the symptom-free period was 112 weeks, on average. The average incision was 27 mm. After neurolysis, the Canaletto implant was placed in contact with the nerve. Immediate postoperative mobilization was commenced. Sensory (pain, DN4, and hypoesthesia), motor (Jamar, muscle wasting), and functional (disabilities of the arm, should, and hand; DASH) criteria were evaluated. Nerve conduction velocity (NCV) of the median nerve was measured. Average follow up was 12.1 months. All measurements were improved after insertion of the Canaletto implant: pain (6.45-3.68), DN4 (4.29-3.48), Quick DASH (55.30-34.96), Jamar (66.11-84.76), NCV (29.79-39.06 m/s), hypoesthesia (76.2-23.8%), wasting (42.9-23.8%). Nevertheless, four patients did not improve, and pain was the same or worse in six cases. Our results show that in recurrent carpal tunnel syndrome, Canaletto implant insertion gives results at least as good as other techniques, with the added advantage of a smaller access incision, a rapid, less invasive technique, and the eliminated morbidity of raising a flap to cover the median nerve.