Capitellum Fracture with Distal Triceps Tendon Avulsion Injury: A Rare Presentation with Literature Review

Capitellum fractures are rare, representing only 1% of all elbow injuries. McKee Type 4 capitellum fractures encompass osteochondral shearing fractures of the capitellum, which involve a significant lateral portion of the trochlear ridge and the trochlea. These fractures may be linked with soft tissue and bone injuries surrounding the elbow, such as distal triceps tendon avulsion (DTTA) injuries. To date, only three case reports in the English literature have documented the correlation between Type 4 capitellum and trochlear fractures with DTTA injuries. Orthopedic surgeons should be vigilant for distal triceps and other posterior elbow injuries, which are often easily overlooked in the presence of prominent primary injuries at the front. The recommended method is prompt surgical intervention for these conditions; however, it is crucial to exercise careful judgment when deciding on the treatment and rehabilitation strategies for such cases.

We present a distinctive case in which an entire capitellum and trochlea were fractured as a single unit in the coronal plane (mimicking McKee type 4 capitellum fractures), along with a DTTA injury in a female patient in her late 40s. This injury was treated using open reduction and internal fixation with cannulated cancellous screws, along with the repair of the DTTA injury.

This unique report provides a comprehensive overview of the pre-operative evaluations, reduction techniques, tendon repair, and post-operative rehabilitation process for such injuries, which showed a favorable outcome. The described fracture pattern has the potential to be categorized as type 5 fractures.