Introduction Diagnostic evaluation of the musculoskeletal system has traditionally been based on medical history, physical examination, and x-rays (techniques that provide limited information), and more recently on computerized axial tomography and magnetic resonance imaging (both very expensive). Ultrasound, a non-invasive and less expensive method, has become an indispensable tool for diagnosing overuse sports injuries. The Imaging Department at the Cuban Sports Medicine Institute (abbreviated in Spanish as IMD) developed a preventive ultrasound diagnostic imaging method and has applied it for the last 15 years as part of the IMD’s medical management of high-performance athletes.

Objectives Identify normal ultrasound patterns for knee structures and extensor mechanism alignment, and perform ultrasound imaging of the knee on asymptomatic, high-performance athletes to detect alterations and endogenous predisposing factors to overuse sports injuries as a basis for adopting preventive action.

Methods A descriptive cross-sectional study was conducted of 300 non-athletes (control) and 100 Cuban Olympic athletes (preselected for the 2000 Olympic Games in Sydney, Australia). The IMD’s Preventive Ultrasound Diagnostic Imaging Method was used to perform static and dynamic ultrasound examinations of both knees of all subjects (800 knees total) to determine normal patterns, detect structural alterations in the knee, and determine extensor mechanism malalignment. For the latter, Anillo’s Patellofemoral Congruence Ultrasound Method was applied to determine the degree of patellar lateralization (RAB angle). Data was processed using descriptive statistics. To compare the ratio of ultrasound knee alterations detected, the Chi-square test was used. Percentiles were calculated based on data from the 600 non-athlete knees and were processed using the SPSS statistics application.

Results Of the 100 athletes studied, 57 were found to have subclinical alterations in one or both knees, distributed as follows: synovitis (30), extensor mechanism malalignment (26), infrapatellar fat pad distortion (15), meniscal echostructure modification (14), ligament echostructure alteration (11), and articular cartilage alteration (7). Analysis of the control group findings established that RAB angle values greater than 13° for both sexes suggest excessive patellar lateralization with respect to the axial axis of the femur, potentially an endogenous risk factor favoring injury.

Conclusions Preventive ultrasound diagnostic imaging of the knee, performed using IMD’s ultrasound scanning methodology and incorporating the normal ultrasound patterns described in this study, enables diagnosis of distortions in the articular and periarticular echostructure prior to the onset of clinical symptoms, as well as observation of endogenous predisposing factors linked to overuse sports injuries. As a result, appropriate measures can be adopted to prevent such injuries and to tailor medical management of high-performance athletes.

Keywords Diagnostic imaging, ultrasound diagnosis, knee, knee injuries, sports medicine, athletic injuries, sports injuries