Pre- and post-operative comorbidities in idiopathic carpal tunnel syndrome: cervical arthritis, basal joint arthritis of the thumb, and trigger digit.

We retrospectively reviewed 633 hands in 362 patients who had idiopathic carpal tunnel syndrome and underwent carpal tunnel release between 1999 and 2009. Electrophysiological studies and simple radiographs of the wrist, cervical spine, and basal joint of the thumb were routinely checked, and patients were also assessed for the presence of trigger digit or de Quervain's disease before and after surgery. Among 362 patients, cervical arthritis was found in 253 patients (70%), and C5-C6 arthritis was the most common site. Basal joint arthritis of the thumb was observed in 216 (34%) of the 633 hands. Trigger digit or de Quervain's disease was observed in 85 of the 633 hands (13%) before surgery, and developed in 67 hands (11%) after surgery. Cervical arthritis, basal joint arthritis, and trigger digit commonly coexist with idiopathic carpal tunnel syndrome. Patient education about these disorders is very important when they coexist with idiopathic carpal tunnel syndrome.