Patellar tendon ultrasonography in asymptomatic active athletes reveals hypoechoic regions: a study of 320 tendons. Victorian Institute of Sport Tendon Study Group.

OBJECTIVE: To compare patellar tendon sonographic findings in active, currently asymptomatic, elite athletes with those in nonathletic controls. DESIGN: Cross-sectional cohort study with convenience control sample. SETTING: The Victorian Institute of Sport Tendon Study Group, an institutional elite athlete study group in Australia. PATIENTS AND PARTICIPANTS: Two hundred elite male and female athletes from the sports of basketball, cricket, netball, and Australian rules football. Forty athletes who had current symptoms of jumper's knee were excluded from analysis, leaving 320 subject tendons in athletes who were currently asymptomatic. Twenty-seven nonathletic individuals served as controls. MAIN OUTCOME MEASURE: Sonographic patellar tendon appearance. We measured the dimensions of subject tendons and noted the presence or absence of hypoechoic regions and tendon calcification. Dimensions of hypoechoic regions were measured, and approximate cross-sectional areas were calculated. Chi-squared analysis was used to test the prevalence of hypoechoic regions in subjects and controls and men and women. RESULTS: In currently asymptomatic subjects, hypoechoic regions were more prevalent in athlete tendons (22%) than in controls (4%), in male subject tendons (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 players (15%) than in other athletes (3%) (p < 0.05). Sonographic hypoechoic regions were present in 35 of 250 (14%) patellar tendons in athletes who had never had anterior knee pain. CONCLUSIONS: Patellar tendon sonographic hypoechoic areas were present in asymptomatic patellar tendons of a proportion of elite athletes but rarely present in controls. This has implications for clinicians managing athletes with anterior knee pain.

Patellar tendon ultrasonography and jumper's knee in female basketball players: a longitudinal study.

OBJECTIVE: To compare patellar tendon sonographic findings at baseline and at follow-up in active female basketball players with and without symptoms of jumper's knee. We hypothesized that baseline sonographic morphology would not reliably predict prognosis and, in particular, that it would not predict the need for surgery. DESIGN: Prospective longitudinal study with 12-month minimum follow-up. SETTING: Institutional elite athlete study group in Australia (Victorian Institute of Sport Tendon Study Group). PATIENTS AND PARTICIPANTS: A total of 15 female elite basketball players with 23 sonographically abnormal tendons and 15 matched control basketball players with 23 sonographically normal tendons. MAIN OUTCOME MEASURES: Sonographic patellar tendon appearance and clinical assessment of symptoms of jumper's knee at baseline and follow-up. Dimensions of abnormal regions were measured. RESULTS: At baseline, the 23 subject tendons contained sonographic hypoechoic regions (six currently symptomatic, eight previously symptomatic only, and nine never symptomatic). At follow-up, the hypoechoic areas in seven tendons had resolved (and caused no symptoms), the hypoechoic areas in 11 tendons had remained essentially the same size (five were symptomatic), and the hypoechoic areas in five tendons had expanded (three symptomatic). At baseline, there were no differences between the mean +/- SD cross-sectional areas of the abnormalities in the tendons that subsequently resolved (15.9 +/- 10.1 mm2) and those that remained unchanged (39.3 +/- 25.8) or expanded (25.3 +/- 12.5). The presence of a baseline sonographic abnormality predicted symptoms of jumper's knee at follow-up (p < 0.05), but the presence of symptoms of jumper's knee at baseline also predicted symptoms at follow-up (p < 0.05). No subject or control missed any games or underwent surgical treatment. CONCLUSIONS: Patellar tendon sonographic hypoechoic areas can resolve, remain unchanged, or expand in active sports-women without predicting symptoms of jumper's knee. Thus, symptoms were not directly related to sonographic tendon morphology. Sonographic hypoechoic regions ought not to constitute per se an indication for surgery.

Patellar tendinosis (jumper's knee): findings at histopathologic examination, US, and MR imaging. Victorian Institute of Sport Tendon Study Group.

PURPOSE: To determine the histopathologic findings of patellar tendinosis ("jumper's knee") demonstrated with ultrasonography (US) and magnetic resonance (MR) imaging. MATERIALS AND METHODS: Twenty-four athletes (28 knees) with jumper's knee (23 men, one women; mean age, 30.9 years) scheduled to undergo open tenotomy underwent US patellar tendon examination. Seventeen patients (19 knees) also underwent MR imaging. Tissue was obtained for histopathologic examination in all 28 cases. Eleven age-, height-, and weight-matched athletes (22 knees) without previous knee symptoms served as control subjects for the US examination. Control material for histopathologic examination was obtained in 20 cadavers (39 knees). Data were analyzed with standard statistical methods. RESULTS: MR imaging and US both revealed an abnormal zone at the proximal patellar tendon attachment. Histopathologic examination revealed mucoid degeneration in all tendons in patients and in 8% (three of 39) of tendons in cadavers (P < .01). CONCLUSION: Jumper's knee is characterized by consistent changes at MR imaging, US, and histopathologic examination and is appropriately described as patellar tendinosis.