Distribution of Osteochondral Lesions in Patients With Simple Elbow Dislocations Based on MRI Analysis

BACKGROUND: The clinical relationship between osteochondral lesions and long-term outcomes and patterns in the elbow joint has not yet been established. A sole evaluation from plain standard radiography may underestimate the severity of bony lesions in patients with simple dislocations. It has been suggested that the mechanism of a posterior elbow dislocation could be inferred from the pattern of bony contusions and osteochondral lesions visible on magnetic resonance imaging (MRI) in patients with simple elbow dislocations. PURPOSE/HYPOTHESIS: The purpose of this study was to describe the incidence and distribution of osteochondral lesions based on MRI findings in patients with simple elbow dislocations. We hypothesized that (1) osteochondral lesions are consistently found in patients with simple elbow dislocations and (2) the distribution and severity of osteochondral lesions may explain the mechanism of the simple elbow dislocation. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective review of 43 patients with simple elbow dislocations was performed in tertiary-level hospitals from January 2010 to August 2019. Two orthopaedic surgeons separately assessed the initial plain radiographs and MRI scans. Osteochondral lesions were evaluated and categorized based on whether they were located (1) on the lateral side (posterolateral capitellum and radial head; type 1) or (2) on the medial side (posterior trochlea and anteromedial facet of the coronoid; type 2). The severity of the osteochondral lesions was assessed according to the Anderson classification. RESULTS: Of the 43 patients, 21 (48.8%) presented with osteochondral lesions on MRI. The type 1 pattern of osteochondral lesions was the most frequently observed on MRI in patients with simple elbow dislocations (69.8% of cases), and these were confirmed by simple radiography. Posterolateral capitellum osteochondral lesions were found in 13 patients. Among them, 10 (76.9%) were advanced-stage lesions (stages III and IV according to the Anderson classification). CONCLUSION: Osteochondral lesions were found on MRI after simple elbow dislocations at a rate of 48.8%. Osteochondral lesions in the posterolateral capitellum were associated with an advanced stage. Clinically, these findings may help surgeons in the diagnosis of osteochondral lesions and in determining how to manage patients with the progression of arthritic changes.