Sonographic incidence of tendon microtears in athletes with chronic Achilles tendinosis

Objective-To assess the number and distribution of tendon microtears in asy mptomatic controls and athletes with chronic Achilles tendinitis or partial thickness tears using high resolution ultrasound. Methods-The mean number of microtears in three random tendon cross sections were recorded per tendon third in 19 asymptomatic volunteers, 16 athletes with symptomatic chronic Achilles tendinitis, and eight athletes with parti al Achilles tendon rupture. Results-Microtears were most numerous in the middle third section of the Ac hilles tendon. Some 67% of tendons in the control group had no microtears, and 28% showed a single microtear. Only 18% of the athletes with chronic Ac hilles tendinitis and none of the athletes with partial tendon rupture were without microtears in the middle third of their Achilles tendon. Of the te ndons with chronic tendinitis, 13% had more than three microtears per secti on which increased to 87% in tendons exhibiting partial rupture. Conclusions-There appears to be an association between microtear formation and Achilles tendon rupture.