gms | German Medical Science

Objectives: Literature regarding osteochondral lesions in patients with elbow dislocation is scarce. The aim of this study was to examine the prevalence of osteochondral lesions on MRI in patients with simple elbow dislocation and their distribution over the elbow joint.

Methods: In this retrospective, single-center study 71 MRIs of patients with simple elbow dislocation between 2012 and 2021 were evaluated. Exclusion criteria included age <16 years, fractures except fractures of the coronoid tip (Regan Morrey type I) and time between injury and MRI of greater than 21 days. Ligamentous and osteochondral injuries were evaluated by a radiologist, a senior and a junior orthopedic surgeon. Osteochondral lesion were classified according to the Anderson classification. Interrater-reliability was assessed using Cohen’s Kappa (95% CI).

Results and conclusion: Mean time between injury and MRI was 6.72±3.98 days and mean patient age was 42.1±15.5 years. A total of 84.5% of patients had lateral collateral ligament tear, 69.0% medial collateral ligament tear, 5.,7% injury of the common extensor origin and 52.1% injury of the common flexor origin.

Osteochondral lesions were found in 28.2% (radiologist) to 62.0% (senior orthopedic surgeon). According to the senior orthopedic surgeon 97.7% were first degree lesions and 2.3% third degree whereas the radiologist classified 69.5% as first degree, 13.0% as second degree, 13.0% as third degree and 4.3% as fourth degree lesions. The junior orthopedic surgeon classified only 40.5% as first degree, but 40.5% as second degree, 16.2% as third degree and 5.4% as fourth degree lesions. Localization of the lesions differed depending on the examiner as well (figure 1 [Fig. 1]). All examiners found most osteochondral lesions on the radial head.

Interrater-reliability was fair to moderate between all examiners for all ligamentous injuries. Substantial agreement between raters was only found between radiologist and junior orthopedic surgeon for coronoid tip fractures (Cohen’s Kappa 0,706 (0,539–0,873)).

Interrater-reliability for osteochondral lesions was fair between radiologist and senior (0,235 (0,065–0,404)) and junior orthopedic surgeon (0,255 (0,029–0,481)) and moderate between senior and junior orthopedic surgeon (0,41 (0,224–0,596)).

In contrast to current literature and clinical assumptions we barely see severe osteochondral lesions in patients with simple elbow dislocation. Overall interrater-reliability between radiologist and surgeons as well as within surgeons was only moderate to fair regarding ligament as well as osteochondral lesions. This puts MRI studies in perspective regarding the reliability of their results.