Isolated Humeral Trochlear Fracture without Associated Elbow Injury: A Rare Case Report

Isolated fractures of the humeral trochlea are exceedingly rare because of the trochlea's deep intra-articular position and anatomical protection from direct trauma. The articular notch formed by the olecranon and coronoid processes shields the trochlea, which also lacks direct muscular or ligamentous attachments. Such fractures typically occur in conjunction with injuries involving the capitellum or the medial and lateral condyles.

We report the case of a 35-year-old male who sustained an isolated trochlear fracture following a physical assault. Initial anteroposterior radiographs demonstrated irregularity of the medial joint space, while the lateral view revealed an intra-articular, half-moon-shaped fragment displaced anterosuperiorly. Computed tomography (CT) confirmed the isolated trochlear fracture. The patient underwent open reduction and internal fixation through a medial approach. At 12 months postoperatively, the patient achieved a complete functional recovery with Mayo Elbow Performance Index score of 100.

Isolated trochlear fractures in adults are uncommon and are frequently associated with capitellar fractures or elbow dislocations. Radiographs and CT scans are essential diagnostic tools, with CT remaining the gold standard for definitive diagnosis and preoperative planning. Stable anatomical fixation through a medial approach provides excellent functional outcomes while minimizing complications.

Isolated trochlear fractures are exceptionally rare injuries. Early diagnosis with CT imaging and stable internal fixation through a medial approach can provide excellent functional and radiological outcomes.