[Replacement of the comminuted radial head fracture by a bipolar radial head prosthesis].

OBJECTIVE: Radial head arthroplasty as a treatment of non-reconstructable, comminuted fractures of the radial head in order to achieve elbow stability and to prevent secondary complications, such as valgus elbow instability and radius proximalization. INDICATIONS: In acute trauma, a radial head fracture not suitable for internal fixation without (Mason grade III) and with (Mason grade IV) concomitant destabilizing injury, Essex-Lopresti injury, sequelae following radial head resection (e.g., elbow instability or wrist pain), failed reconstruction of the radial head, and tumor-associated radial head or neck resection. CONTRAINDICATIONS: General medical contraindications for surgical intervention, cobalt-chromium allergy, and osteoporosis of the proximal radius. SURGICAL TECHNIQUE: In supine position, a lateral or posterolateral approach at the elbow was used. The annular ligament was exposed and the radial neck identified just above the bicipital tuberosity. In pronation of the forearm in order to protect the radial nerve, the medullary canal was prepared using rasps. The size of the implant was determined using trial stems. A distance of 0.5 mm between the head of the prosthesis and the capitulum humeri was recommended. After using a small bone plug, the prosthesis was cemented with respect to the anatomical radial curvature. After reconstruction of the annular ligament, the stability of the elbow was verified. In case of instability, the medial collateral ligament was reconstructed and afterwards the wound closed. POSTOPERATIVE MANAGEMENT: Early mobilization begins the day after surgery. In case of additional injuries, the elbow was supported by an above-elbow cast for 3-4 weeks. To prevent heterotopic ossification, nonsteroidal antiinflammatory drugs were used for up to 4 weeks with gastric protection.
RESULTS: A total of 13 patients with 15 radial head prosthesis were analyzed at a mean follow-up of 29.5±20.8 months. In all patients, the elbow was stable. Subjectively, good and excellent results were found with one exception. Compared to the pretrauma status, the subjective rate was 78±12%. Based on the Radin and Riseborough score, 6 of the results were good and 9 were fair. According to the Broberg and Morrey score, 1 result was very good, 8 were good, and 6 were fair. The mean DASH score was 9.9±9.7 points. Two temporary nerve lesions were observed. Five patients were diagnosed with heterotopic ossification stage I, while 2 patients were classified with stage II on the Brooker scale.