Open reduction and internal fixation of capitellar fractures with headless screws. Surgical technique.

BACKGROUND The outcome of operatively treated capitellar fractures has not been reported frequently. The purpose of the present study was to evaluate the clinical, radiographic, and functional outcomes following open reduction and internal fixation of capitellar fractures that were treated with a uniform surgical approach in order to further define the impact on the outcome of fracture type and concomitant lateral column osseous and/or ligamentous injuries. METHODS A retrospective evaluation of the upper extremity database at our institution identified sixteen skeletally mature patients (mean age, 40 +/- 17 years) with a closed capitellar fracture. In all cases, an extensile lateral exposure and articular fixation with buried cannulated variable-pitch headless compression screws was performed at a mean of ten days after the injury. Clinical, radiographic, and elbow-specific outcomes, including the Mayo Elbow Performance Index, were evaluated at a mean of 27 +/- 19 months postoperatively. RESULTS Six Type-I, two Type-III, and eight Type-IV fractures were identified with use of the Bryan and Morrey classification system. Four of five ipsilateral radial head fractures occurred in association with a Type-IV fracture. The lateral collateral ligament was intact in fifteen of the sixteen elbows. Metaphyseal comminution was observed in association with five fractures (including four Type-IV fractures and one Type-III fracture). Supplemental mini-fragment screws were used for four of eight Type-IV fractures and one of two Type-III fractures. All fractures healed, and no elbow had instability or weakness. Overall, the mean ulnohumeral motion was 123 degrees (range, 70 degrees to 150 degrees ). Fourteen of the sixteen patients achieved a functional arc of elbow motion, and all patients had full forearm rotation. The mean Mayo Elbow Performance Index score was 92 +/- 10 points, with nine excellent results, six good results, and one fair result. Patients with a Type-IV fracture had a greater magnitude of flexion contracture (p = 0.04), reduced terminal flexion (p = 0.02), and a reduced net ulnohumeral arc (p = 0.01). An ipsilateral radial head fracture did not appear to affect ulnohumeral motion or the functional outcome. CONCLUSIONS Despite the presence of greater flexion contractures at the time of follow-up in elbows with Type-IV fractures or fractures with an ipsilateral radial head fracture, good to excellent outcomes with functional ulnohumeral motion can be achieved following internal fixation of these complex fractures. Type-IV injuries may be more common than previously thought; such fractures often are associated with metaphyseal comminution or a radial head fracture and may require supplemental fixation.