Complex Elbow Trauma: Surgical Management of a Type IV Capitellum Fracture in a Young Female

The Anatomical Complexity of Capitellar Shear Injuries

Coronal shear fractures of the distal humerus, particularly those isolated to the capitellum, are rare and complex injuries that comprise less than one percent of all elbow fractures. Among these variations, the Type IV fracture—as classified by McKee—is exceptionally complex because it involves a shear fracture of the capitellum that extends medially across the joint line to include a substantial portion of the trochlea. This injury pattern typically results from a fall onto an outstretched hand with the elbow partially flexed, transferring severe axial forces through the radial head directly into the humeral condyle. Because these fractures are entirely intra-articular and frequently lack any attached soft tissue or muscle to provide a blood supply, the structural bone fragments are highly unstable, prone to displacement, and carry a high risk of avascular necrosis if not treated promptly.

Diagnostic Nuances and Radiographic Challenges

Accurately diagnosing a Type IV capitellum fracture poses a significant clinical challenge due to the complex overlapping bony anatomy of the elbow joint on standard x-rays. On a conventional lateral radiograph, this injury often manifests subtly as the “double arc sign,” which represents the displaced, parallel articular dr abhishek kumar ortho surfaces of the fractured capitellum and trochlea. Because standard films frequently underestimate the true size, fragmentation, and medial extension of the injury, a high-resolution Computed Tomography (CT) scan with three-dimensional reconstructions is a clinical necessity. This advanced imaging allows the orthopedic surgeon to map out the precise fracture lines, evaluate the degree of articular surface comminution, and formulate a targeted preoperative plan for structural stabilization.

Open Reduction and Internal Fixation with Herbert Screws

Achieving optimal functional outcomes and preventing long-term joint stiffness or post-traumatic arthritis requires anatomical reduction and rigid internal fixation. The surgical approach typically involves an extended lateral or anterolateral exposure to visualize the joint surface directly. Once the displaced bone fragments are carefully aligned to restore the smooth contour of the articular cartilage, internal fixation is achieved using headless compression screws, such as Herbert screws. These specialized screws are countersunk completely beneath the cartilage surface, protecting the moving joint while providing continuous compression across the fracture line. This stable, low-profile fixation allows patients to bypass prolonged casting and begin early, controlled range-of-motion exercises, which are essential for minimizing scar tissue formation and restoring normal elbow mobility.