Elbow Instability / Dislocation
Elbow instability is when the forearm (radius and ulna) dislocates from the upper arm (humerus). The elbow gains stability from 3 elements:
Bones – The radial head and the coronoid process are important bony stabilisers and act as a buttress to prevent dislocation.
Ligaments – Ligaments are soft tissue guy ropes that bind bones together. The two most important ligaments in the elbow are the one on the inner aspect of the elbow (medial collateral ligament) and the one on the outer side of the elbow (lateral ulna collateral ligament).
Muscles – The elbow is surrounded by muscles that move the forearm and wrist. When these muscles are working it confers better stability to the elbow. This underlies the principle of early movement after an elbow dislocation.
The elbow dislocates when one or more of these elements are damaged. If the dislocation only involves the soft tissue elements (ligaments and muscles) it is termed a ‘simple dislocation’. If however it also involved the bones it is terms a ‘complex dislocation’. Whilst some dislocations can be treated conservatively if they are neglected or treated improperly this can lead to recurrent instability, stiffness or post-traumatic osteoarthritis.
How is the diagnosis made?
Examination at the time of dislocation of often very difficult due to pain. You should attend an Emergency Department and have the elbow put back (reduced) immediately to mitigate the risk of neurological complications and cartilage damage. Once the elbow is reduced it is immobilised in plaster (above elbow backslab) and X-rays taken to confirm that it is no longer dislocated. A CT or MRI scan may be necessary to characterise exactly what structures are damaged and how badly they are damaged.
What is the treatment?
The primary aim of treatment is to restore and maintain normal alignment of the joint, permit movement and prevent complications such as instability, stiffness or osteoarthritis. In the first instance this involves examination by an upper limb specialist for clinical assessment and serial X-rays.
Active movement should commence as soon as possible after a dislocation. Stability is improved by performing exercises while lying on your back (supine) with the shoulder flexed (brought forward) to 90 degrees. In this position gravity helps to maintain the congruency of the joint.
Certain types of dislocation require immediate surgery and other may require surgery later. This usually involves restoration of at least 3 of the 4 main stabilising structures (lateral ulnar collateral ligament, radial head, coronoid process and/or medial collateral ligament). If other elements are damaged and felt to be contributing to the instability they too may need addressing through surgery. In some circumstances a surgeon may apply an external fixator (frame) to the elbow to maintain stability.
Rehabilitation is supervised by one of our team of physiotherapists. Exercises are started immediately and the sling is used for social protection only. By 6 weeks you should be able to return to normal activity and by 12 weeks you should be able to return to sports.
What are the risks of surgery?
The risks are low but include infection, bleeding, nerve injury, scar tenderness, stiffness, new pain at the elbow, recurrent instability, osteoarthritis and worsening of symptoms.