Boeth et al Journal of Experimental Orthopaedics (2017) 4:6 DOI 10.1186/s40634-017-0080-x Journal of Experimental Orthopaedics RESEARCH Open Access MRI findings of knee abnormalities in adolescent and adult volleyball players Heide Boeth*, Aoife MacMahon, Felix Eckstein, Gerd Diederichs, Arne Schlausch, Wolfgang Wirth and Georg N Duda Abstract Background: To longitudinally and cross-sectionally evaluate knee abnormalities by sex and age in adolescent and adult volleyball athletes over years using magnetic resonance imaging (MRI) Methods: Thirty-six high-level volleyball athletes (18 adolescents: 56% female, mean age 16.0 ± 0.8 years; and 18 adults: 50% female, mean age 46.8 ± 5.1 years) were imaged by MRI at BL and at 2-year follow-up (FU) Prevalence and severity of cartilage lesions, subarticular bone marrow lesions (BMLs), subarticular cysts, osteophytes, and ligament and meniscus integrity were evaluated by sex and by age cohort (adolescents and adults) using the whole-organ MRI score (WORMS) Results: There were no significant longitudinal changes in any of the features within any of the sex or age groups No significant differences were found in overall prevalence or severity of any of the features between males and females, although at FU, males had a significantly higher prevalence of osteophytes in the medial femorotibial joint (MFTJ) than females (p=0.044) Compared to adolescents, adult volleyball players had a significantly greater prevalence and severity of cartilage lesions (p