Excision of radial head fractures with medially displaced fragments using 2 incisions: the nutcracker effect.

Marginal radial head fractures with displaced fragments are relatively common, especially when associated with a concomitant posterior elbow dislocation. The separated fragments are usually displaced forward and outward into the lateral part of the elbow or proximally in the elbow joint. Ulnar displacement of the separated fragments has been described in few cases, and in most of them treatment consisted of excision of the entire radial head.This article present a case series of 4 Mason type 3 radial head fractures with medially displaced fragments that had to be excised via a separate medial incision. Surgery was performed using 2 incisions, the standard Kocher and a medial incision; complete radial head excision was performed. Clinical and radiological assessment was done for all cases. Pain and range of motion at 2 years and any evidence of heterotrophic ossification were assessed. All patients had some degree of flexion deformity at final follow-up. One patient had some loss of rotation. No heterotrophic ossification existed in any patient. The authors postulate that the medial displacement may have been due to a nutcracker effect that caused the medial portion of the radial head to be compressed between the capitellum and the radial shaft and lateral part of the radial head. Such injuries are rare, and postoperative loss of flexion should be expected. Posterior elbow dislocation may not be present in all cases.