Ultrastructural analysis of ruptured tendon from anabolic steroid users.

Tendon rupture has been linked with anabolic steroid abuse on the basis of a small number of published case reports. Although experimental data from animal models suggest steroids alter the biomechanical properties of tendon, ultrastructural evidence to support this theory is lacking. Indeed, microscopic analysis of human tendon from steroid users has not previously been reported. In this study, specimens of ruptured human tendon from four patients were biopsied during surgical repair. Two of the subjects were anabolic steroid users, and two subjects were used as nonsteroid-user controls. Ruptured tendon from both groups was examined using electron microscopy. No differences in collagen fibril ultrastructure were seen. We conclude that anabolic steroids did not induce ultrastructural collagen changes that might predispose to tendon rupture in humans.