Radiographic Predictors of Medial Collateral Ligament Injury and Stability of the Elbow

Background: It has been postulated that injury to the medial collateral ligament (MCL) of the elbow is rare in cases of elbow fracture-dislocation, and if the MCL is torn, it does not require surgical repair. Elbow fracture-dislocations with MCL insufficiency are associated with recurrent instability, secondary surgery, and the development of posttraumatic arthritis. With the current study, our aim was to investigate whether evidence of an MCL attachment-site fracture on a radiograph or computed tomography (CT) scan is predictive of MCL insufficiency, the need for MCL repair, and postoperative instability. Methods: This retrospective study included 219 patients (median age of 50 years; 53% female) with elbow fracture-dislocations treated at 2 Level-I trauma centers during the period of 2005 to 2016. Patients were followed for a median of 6.3 years to determine postoperative stability. Operative notes and radiology reports were reviewed to confirm MCL insufficiency and periarticular fractures. Radiographs and CT scans were analyzed by a musculoskeletal fellowship-trained emergency radiologist and a board-certified upper-extremity orthopaedic surgeon. Results: Of the 33 patients with confirmed fractures at an MCL attachment site, 26 (79%) had MCL insufficiency, whereas of the 186 patients without fracture at an MCL attachment site, only 17 (9%) had MCL insufficiency. Of the 6 patients with an attachment-site fracture and MCL insufficiency who did not undergo initial MCL repair, 5 required reoperation. Of the 7 patients without an attachment-site fracture and with MCL insufficiency who did not undergo initial MCL repair, only 1 required reoperation. Conclusions: Fractures involving an MCL attachment site, regardless of their size, help to predict MCL insufficiency. These fractures can be visualized using initial radiographs and CT scans that are routinely obtained. Additional research is required to assess these findings. Our findings further suggest that repairing an MCL-complex injury in cases of fracture-dislocation in which the fracture has occurred at an MCL attachment site may improve elbow stability and decrease the likelihood of requiring reoperation. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.