Reconstruction for elbow instability caused by congenital aplasia of the ulnar coronoid process—a case report

A 13-year-old girl presented at our tertiary referral center with bilateral posterior radial head dislocation and aplasia of the ulnar coronoid process (Figure 1). She was pain-free, had a 30-degree lack of elbow extension, limited forearm pronation and supination (80–20 degrees on the right side, 80–0 degrees on the left side), but no signs of elbow instability. After sev- eral years without any relevant restrictions during her daily life activities, she returned to our outpatient clinic at the age of 17 with increasing pain on both sides and distinct radiological signs of posterior humeroulnar dislocation due to aplasia of the ulnar coronoid process (Figure 2). A review of the litera- ture did not yield any information about that specific defor- mity or any possible treatment options. We decided to recon- struct the right elbow via an anteromedial approach, using a tricortical iliac crest bone graft as a coronoid equivalent and artificial bony restraint to the elbow joint.