The clinical and radiographic features of chronic posterior subluxation
or dislocation of the radial head were studied in thirty-four elbows of
twenty-seven patients. Three characteristic radiographic types were noted:
Type I, subluxation; Type II, posterior dislocation with minimum
displacement; and Type III, posterior dislocation with substantial proximal
migration of the radius. Follow-up of eighteen patients (twenty-one elbows)
revealed that posterior displacement did not usually cause serious
functional impairment except for loss of rotation of the forearm. The least
common presentation, Type-I subluxation, caused pain and clicking and was
associated with late degenerative arthritis. Cosmetic deformity due to
prominence of the radial head was also a cosmetic problem, particularly
with Type-III dislocation.