Patellar tendon ultrasonography in asymptomatic active athletes reveals hypoechoic regions: A study of 320 tendons

Objective: To compare patellar tendon sonographic findings in active, curre ntly asymptomatic, elite athletes with those in nonathletic controls. Design: Cross-sectional cohort study with convenience control sample. Setti ng: The Victorian Institute of Sport Tendon Study Group, an institutional e lite athlete study group in Australia. Patients and Participants: Two hundred elite male and fe male athletes from the sports of basketball, cricket, netball, and Australian rules football. Forty athletes who had current symptoms of jumper's knee were excluded fro m analysis, leaving 320 subject tendons in athletes who were currently asym ptomatic. Twenty-seven nonathletic individuals served as controls. Main Outcome Measure: Sonographic patellar tendon appearance. We measured t he dimensions of subject tendons and noted the presence or absence of hypoe choic regions and tendon calcification. Dimensions of hypoechoic regions we re measured, and approximate cross-sectional areas were calculated. Chi-squ ared analysis was used to test the prevalence of hypoechoic regions in subj ects and controls and men and women. Results: In currently asymptomatic subjects, hypoechoic regions were more p revalent in athlete tendons (22%) than in controls (4%), in male subject te ndons (30%) than in female subjects (14%), and in basketball players (32%) than in other athletes (9%) (all p < 0.01). Bilateral tendon abnormalities were equally prevalent in men and women but more prevalent in basketball pl ayers (15%) than in other athletes (3%) (p < 0.05). Sonographic hypoechoic regions were present in 35 of 250 (14%) patellar tendons in athletes who ha d never had anterior knee pain. Conclusions: Patellar tendon sonographic hypoechoic areas were present in a symptomatic patellar tendons of a proportion of elite athletes but rarely p resent in controls. This has implications for clinicians managing athletes with anterior knee pain.