Elbow luxation in a patient with congenital dislocation of the radial head

Background

Elbow dislocations are the second most common dislocation of the upper extremity after shoulder dislocations.1 Posterior dislocations are the most common, and although elbow dislocation can occur after trauma, it is also seen as a congenital dislocation of the radial head.2 The incidence of congenital dislocations varies between 0.06% and 0.16%, and is mostly bilateral.3 4 Most of the literature about congenital dislocations consists of case reports and is predominantly described in children and does not describe additional traumatic luxation in patients with a pre-existing congenital dislocation of the radial head. Identifying and recognising these patients are important for the identification and treatment, in this case, the reposition of the luxation. Therefore, in this case study, we would like to present an adult patient with a congenital dislocation of the radial head who had an additional luxation of the ulnohumeral joint after trauma. To our knowledge, this is the first case report regarding this unique combination.

The congenital dislocation was initially unrecognised. However, during the planning of the closed reduction and the re-examining of the imaging, we determined that the dislocation of the radial head was indeed congenital, but compared with the other side, there was also a luxation.

Case presentation

A male patient in his 30s, with no history, presented to the emergency department (ED) after he fell with his bicycle. He fell directly on his right elbow, which was painful, and he could not move since he had the accident. He was transported to the ED by ambulance.

In the ED, he had a full examination. His right elbow was painful and he kept the elbow in a flexed position with his hand on his abdomen. An abnormal anatomy (the radial head was seen behind the olecranon) was seen with swelling of the entire elbow. With palpation, the patient experienced pain in the olecranon and both epicondyles. The three-point bony relationship was disrupted because the olecranon could not be palpated properly due to the radial head that interfered. His skin had a normal colour and was intact. The neurological examination was normal and the radial pulse was palpable. No other injuries were found.

Anteroposterior and lateral radiographs of the right elbow were obtained (figure 1). The initial report described a lateral luxation with a dislocation of the radial head more proximal. There was significant swelling of the soft tissue and a small fragment seen posteriorly of the epicondyle. An additional view of the wrist (figure 2) was also made, which showed a strikingly prominent ulna with a smaller radiocarpal relation and positive ulnar variance.

Physical examination of the left (unharmed) elbow also showed an abnormal anatomy with a proximal dislocation of the radial head. Examination was completely performed without pain and he showed full range of motion of the left elbow.

To compare both elbows, an X-ray of the left elbow (figure 3) was obtained, which showed the dislocation of the radial head that we already discovered on physical examination. The difference between the right and left side was the projection of the radial head and ulna on both epicondyles and trochlear joint. In the right elbow, there was a lateral luxation of the ulnohumeral articulation and subluxation of the radial head. Therefore, we concluded congenital deformities but with an additional luxation on the right side of the ulnohumeral joint after trauma.

Due to the complex nature of the luxation, a CT scan was made to rule out intra-articular fractures. The CT scan of the right elbow (figure 4) confirmed the subtle avulsion of the olecranon and an irregular aspect of the coronoid process besides the previously mentioned luxation and dislocation. A CT scan of the left elbow (figure 5) was made for comparison.

The closed reduction of the right elbow was performed in the ED with procedural sedation and analgesia. The patient was in a sitting position, with the elbow in 90° flexion beside his body. One person stabilised the upper arm against stretching. The other person held the right hand with one hand and the underarm with the other hand. Then, axial traction was applied by putting the hand, wrist and forearm in a prone position, which was not enough for a reduction in this case. Pronation and supination have been alternated while maintaining traction. The one holding the elbow eventually felt the ulnohumeral joint move from lateral to medial and a small difference in the position of the radial head, which also moved medially. The stability and range of motion were tested and had been improved. After reduction, an X-ray was obtained to confirm the correct position and to see if there were no additional fractures (figure 6). After this, the patient was given a cast immobilisation and discharged home.

Outcome and follow-up

After 1 week, during cast change, the patient still experienced pain in the elbow. The cast was continued for a total of 3 weeks. After this period, the patient was given a brace for slow mobilisation with extra support. The patient regained full range of motion in 2 months.