Review Question - QID 211562

This patient has sustained a capitellar coronal shear fracture, as depicted by the double arc sign in Figure A. The classically described position and approach for his injury is supine using a lateral column Kaplan or Kocher approach.

Capitellar coronal plane fractures can be treated by anterolateral, lateral (Kaplan or Kocher), and posterior surgical approaches. The most commonly preferred approaches are the lateral approach for isolated capitellum fractures and capitellum fractures that extend to the trochlear ridge, and the posterior approach for the fractures that involve both the capitellum and trochlea. When a lateral column approach is used, the origin of the wrist extensors is stripped off the lateral epicondyle and the elbow is translated medially. This approach facilitates the manipulation, anatomic reduction and fixation of the fractured fragment as the instruments can be used more easily.

McKee et al. investigated coronal shear fractures of the distal end of the humerus. They reported that all patients were treated with open reduction internal fixation, with early elbow motion allowed. They highlighted that all patients had a good/excellent functional results according to the elbow-rating scale of Broberg and Morrey.

Stamatis et al. retrospectively reviewed the treatment and functional outcome of coronal shear fractures of the distal humerus. They reported that all fractures healed within 6 to 9 weeks with a single case of osteonecrosis and post-traumatic arthritis, with preservation of muscle strength of the major muscle groups of the operated elbow compared to the uninjured elbow. They concluded that recognition of coronal capitellar fractures, prompt treatment with anatomic reduction and internal fixation, and early rehabilitation can lead to excellent functional outcomes.

Durakbasa et al. investigated the management, complications and outcomes after distal humeral coronal plane fractures. They reported that all patients were treated by open reduction and internal fixation either by lateral or posterior approach. They highlighted the complications including avascular necrosis (27%), degenerative arthritis (40%), joint step-off (40%), heterotopic ossification (47%), nonunion (7%), and implant failure (7%).

Figure A depicts the double arc sign seen in capitellar coronal shear fractures and is created from the subchondral bone of the displaced capitellum and lateral trochlear ridge.

Incorrect Answers:
Answer 1 and 2: An olecranon osteotomy is indicated in fractures which require need for extensive articular fixation. The osteotomy would increase the morbidity of the case described unnecessarily.
Answer 3: A posterior approach may be considered for the fractures that involve both the capitellum and trochlea, but this is not the classically described approach for simple capitellar shear fractures.
Answer 4: A medial sided approach would not allow direct visualization and reduction for a simple coronal shear capitellar fracture.