Circulatory disturbances in the throwing hand of baseball pitchers.

Three cases of circulatory disturbance with ulcer formation in the pitching hand of baseball pitchers are reported. The pathophysiology was of an entirely new entity. In one case, the neurovascular bundles of the middle finger were entrapped by the proximal edges of Cleland's ligaments. In the other two cases, the blood vessels to the index and middle fingers were compressed within the lumbrical canal. Hypertrophy of the lumbrical muscles and/or thickening of the palmar aponeurosis were responsible for the compression of the vessels. Surgical release of Cleland's ligaments or palmar aponeurosis, including superficial transverse fiber and vertical septa, resulted in good recovery of the circulation of the involved fingers. All of the pitchers returned to professional or college league baseball without recurrence of the ulcer.