Plain radiography and computed tomography at three months after the injury showed that the avulsion fracture of the lateral epicondyle became displaced and malunited, the radiohumeral joint
had widened on the anteroposterior view, and the posterior subluxation of the radial head had widened on the lateral view (Figures 2(a)-2(e)).
The differential diagnosis in lateral elbow pain includes lateral epicondylitis, radial tunnel syndrome, occult fracture, lateral synovial plica, injury to the lateral collateral ligament, and radiohumeral joint
disease (synovitis, osteoarthritis).
Type 3 synostoses are further divided into three different subgroups: type 3A, which affects the proximal third of the forearm without involving the articular surface and is treated as type 2; type 3B, where only the radioulnar joint involved is treated with the excision of the radial head; type 3C, where the radiohumeral joint
is involved and, consequently, the treatment is an arthroplasty [4, 5].
The elbow joint is opened anteriorly, and the capsule released circumferentially; the humeroulnar and radiohumeral joints
are then disarticulated.