Flexor pulley system: anatomy, injury, and management.

Flexor pulley injuries are most commonly seen in avid rock climbers; however, reports of pulley ruptures in nonclimbers are increasing. In addition to traumatic disruption, corticosteroid-induced pulley rupture has been reported as a complication of treating stenosing tenosynovitis. Over the last decade, there have been 2 new developments in the way hand surgeons think about the flexor pulley system. First, the thumb pulley system has been shown to have 4 component constituents, in contrast to the classic teaching of 3 pulleys. Second, in cases of zone II flexor tendon injury, the intentional partial A2 and/or A4 pulley excision or venting is emerging as a component for successful treatment. This is challenging the once-held dogma that preserving the integrity of the entire A2 and A4 pulleys is indispensable for normal digit function.