Chronic Posttraumatic Dislocation of Radial Head With Ulnar Nerve Entrapment in a Child: A Case Report and Literature Review

Irreducible isolated anteromedial radial head dislocation due to ruptured anterior capsule and annular ligament interposition: A case report

Traumatic radial head dislocation without a bone-associated lesion is uncommon, and irreducible cases are rare. We herein present a case of isolated irreducible anteromedial radial head dislocation due to anterior capsule and annular ligament interposition in a 16-year-old female patient. The patient was injured when she was thrown by an opponent during a judo match, and her right elbow was outstretched, combined with forearm pronation. Open reduction was required because of soft tissue interposition into the radiocapitellar joint. The ruptured anterior capsule and annular ligament were repaired using the overlapping suture technique; hence, the radial head was stabilized. At 3.5 years follow-up, the patient had satisfactory elbow function, and redislocation did not occur; however, mild degenerative changes were observed on radiographs. We discussed the injury mechanism using anatomical features in this case and previous literature.

Isolated Proximal Radioulnar Joint Instability: Anatomy, Clinical Presentation, and Current Treatment Options

Isolated proximal radioulnar joint instability is an uncommon and often challenging problem that may manifest as recurrent instability of the proximal aspect of the radius, usually during forearm pronation and supination. Instability is due to deficiency of the stabilizing structures around the proximal aspect of the radius, and biomechanical studies have highlighted the importance of the annular ligament and the interosseous membrane in both transverse and longitudinal plane stability. Reconstruction of the stabilizing structures around the radial head often is indicated in cases of recurrent instability and includes joint-preserving procedures such as annular ligament reconstruction, proximal ulnar osteotomy, and interosseous membrane reconstruction. Rarely, salvage procedures such as interpositional arthroplasty or 1-bone forearm reconstruction are necessary. A thorough understanding of the anatomic structures that stabilize the proximal aspect of the radius and the complexities of forearm biomechanics is required in order to successfully diagnose and manage this condition.