Background Shoulder pathology in adult tennis players including rotator cuff pathology is well known. However, early adaptations have not previously been studied in the adolescent elite tennis players.

Objectives To describe magnetic resonance imaging (MRI) findings in the shoulder in asymptomatic elite adolescent tennis players.

Design A MRI scan using a 3 Tesla scanner of both shoulders were performed. PD (proton density) weighted images with fat-saturation in oblique coronal, oblique sagittal and axial planes together with oblique sagittal T2 images were reviewed especially for the presence of abnormalities regarding labral lesions and rotator-cuff lesions by two radiologists in consensus. The MRI scans were evaluated by to independent experienced radiologists in a blinded manner according to a pre-defined protocol. Data were collected retrospectively for the dominant arm and contralateral arm respectively. Statistical analyses were performed using SPSS software.

Setting Testing environment at Medical Rontgen, Sweden.

Participants 35 adolescent elite tennis players from the Swedish national team were selected (ages 13–24 years median age 17). 15 boys and 20 girls participated in the study.

Intervention Findings were described according to a predefined protocol.

Main outcome measurements MRI findings of the dominant and non-dominant shoulder.

Results 19 players (54%) had a normal MRI examination and 16 players (46%) had abnormal findings of which 14 players showed affected tendons/tendinosis. The predominant findings were made in infraspinatus (n=10), Supraspinatus (n=5) and Subscapularis (n=1). Two players had findings in both infra- and supraspinatus.

Conclusions This is the first study describing MRI findings in adolescent elite tennis players, revealing infraspinatus and supraspinatus affected tendons/tendinosis in this asymptomatic overhead athletic population. The results can serve as the baseline for a future prospective longitudinal cohort study.