Posteromedial elbow impingement: magnetic resonance imaging findings in overhead throwing athletes and results of arthroscopic treatment.

PURPOSE: The purpose of this study was to define the magnetic resonance imaging (MRI) pattern and assess the results of arthroscopic treatment of posteromedial elbow impingement in overhead throwers.

METHODS: Over an 8-year period, 9 throwing athletes diagnosed with posteromedial elbow impingement were retrospectively identified. All patients had either a noncontrast or direct arthrogram-MRI study that was reviewed by a single, fellowship-trained musculoskeletal radiologist blinded to the clinical diagnosis. Arthroscopic treatment included debridement of posteromedial synovitis, loose body removal, and excision of the olecranon spur. All patients underwent a physical examination and completion of the Andrews-Carson scale at a mean of 68 months (range, 25 to 112 months).

RESULTS: All patients were male, with a mean age of 21.0 years (range, 17 to 34 years). The dominant arm was affected in all patients. The mean length of symptoms before surgery was 9 months (range, 5 to 24 months). At MRI, a reproducible pattern of pathology was noted. All patients had pathology at the articular surfaces of the posterior trochlea and the anterior, medial olecranon. The findings ranged from abnormal edema-like signal in the hyaline cartilage to cartilage defects and subjacent, subchondral bone marrow edema. Findings at surgery included posteromedial synovitis and olecranon spurring in all patients and loose bodies in 3 patients. On the basis of the Andrews-Carson scale, the subjective and objective outcome was considered excellent in 7 patients and good in 2.

CONCLUSIONS: Posteromedial elbow impingement is a source of disability in the overhead throwing athlete. Correlation of history and physical examination with imaging findings is essential to confirm the diagnosis. This study indicates that MRI identifies a reproducible pattern of pathology in throwing athletes with this disorder. These MRI findings correlate highly with arthroscopic evaluation. Arthroscopic debridement, olecranon spur excision, and loose body removal allow return to throwing sports and reliable subjective and objective results in carefully selected patients.