The glenohumeral joint is the most frequently dislocated joint and usually occurs following an injury such as a fall or in a collision during sports including AFL, basketball or rugby. The direction of dislocation is usually anterior and most will self-reduce, but it is estimated 30-40% require a formal reduction.
The most common injury associated with a traumatic shoulder dislocation is tear of the fibrous labrum that surrounds the glenoid (Bankart lesion). Associated injuries include a fracture of the rim of the glenoid (bony Bankart lesion), an impaction fracture on the back of the humeral head (Hill Sachs lesion) and nerve injury, typically to the axillary nerve.
Tears of the rotator cuff tendons also may occur, usually in patients over 45 years and it is recommended to obtain imaging for these patients.
These injuries can cause permanent shoulder dysfunction if they are not identified and properly treated. The main problem following a shoulder dislocation is recurrent instability. Patients under 30 years of age, and those that play collision or overhead sports, have a 70-95% risk of recurrent instability.
Patients with this recurrent instability have difficulty because the shoulder feels weak or unstable in the overhead position, even if it does not frankly dislocate. In published series the long-term prognosis after a single anterior dislocation found at 25 years, two thirds of patients had arthritic changes on x-rays.
Treatment is based on the patient’s unique combination of age, symptoms and functional requirements. Physiotherapy is the first line treatment for most cases, even though it does not address the labral tear. The aim is to improve the strength and coordination of the dynamic stabilisers that surround the glenohumeral joint and improve scapula control.
The patient should rest their arm in a sling for one week or until comfortable following a first-time dislocation. Physiotherapy can begin in the first week following injury and return to full contact sports can be expected at around three months.
Stabilisation surgery is generally reserved for patients who either have had recurrent dislocations or are at high risk of developing recurrent instability.
A dislocation with associated fracture, rotator cuff tear or nerve injury would require prompt review. A first dislocation in a patient under 30 years and playing contact or high-risk sport, in the military, or with a job which involves climbing or overhead lifting may prefer the option of stabilisation surgery to reduce the likelihood of a further dislocation and subsequent time off sport or work.
Second (or greater) traumatic dislocation, persistent pain, weakness, or lack of confidence in the shoulder despite physiotherapy would indicate a failure of non-operative treatment and warrant further work-up.
Key messages
- The glenohumeral joint is the most frequently dislocated joint
- Treatment is based on the unique circumstances of the individual, with physiotherapy first line
- Stabilisation surgery is generally for recurrent dislocations.
Author competing interests – nil