Post-traumatic proximal radioulnar synostosis: current concepts on the clinical presentations, classifications and open surgical approaches.

In the forearm, post-traumatic heterotopic ossification usually forms as a proximal radioulnar synostosis. It can occur after soft tissue injury involving the interosseous membrane or after surgery involving the radio and ulna, like distal biceps tendon repair. It can also be induced by radial head dislocation or fracture. Screening radiography can be used to select the appropriate time for excision. The synostosis can be resected when the ectopic bone margin and trabeculation appear mature on x-rays. An interval of 6-12 months from the injury is generally recommended based on ectopic bone maturity. Selection of the surgical approach depends on: site, extension (elbow joint or proximal radioulnar joint, severity of the initial articular surface and periarticular tissue injury. The posterolateral approach is indicated for synostoses: at or distal to the bicipital tuberosity, at the level of the radial head and proximal radioulnar joint. The posterior global approach is recommended when the forearm synostosis is associated with complete bony ankylosis of the elbow involving the distal aspect of the humerus. After surgical resection of a proximal radioulnar synostosis, the exposed bone surfaces can be covered with interposition material to minimize recurrence.