Blood flow in chronic Achilles tendinosis. Radioactive microsphere study in rabbits.

Cerium-labeled microspheres were used for blood-flow measurements in 7 New Zealand white rabbits with exercise-induced chronic Achilles paratenonitis and tendinosis. The blood flow increased 1.9 times more on the exercised side as compared with the contralateral, unexercised (control) side with respect to both the tendon and the paratenon. The blood flow of the tendon of the exercised leg showed a strong correlation with the blood flow in the paratenon of the ipsilateral side (r = 0.81). We concluded that the relative contribution of blood from the paratenon to the tendon remained unaltered in the exercised tendon and that degeneration of the tendon cannot be primarily explained by chronic circulatory impairment.