Shoulder injuries are common. In young patients, they are usually a result of sports injuries while in older patients, they follow a trip or fall. Shoulder injuries may also be the result of a repetitive strain injury.

They vary in severity from an acute sprain or tendonitis – which resolves in a few days with rest, anti-inflammatories and gentle exercise – to a dislocation or severe fracture which may require an operative fixation or, sometimes, a shoulder replacement in elder patients.

The shoulder joint is made up of a ball and a shallow cup surrounded by multiple ligaments, capsule and a shallow cartilage lip. The four muscles around the shoulder joint, called the rotator cuff, both stabilise and move the joint.

The shoulder joint is a true ball-and-socket joint and the body sacrifices stability for mobility, making it the most easily dislocatable joint in the body.  This typically occurs in young patients in sports. The shoulder usually dislocates forward (anterior), although backward (posterior) and downward (inferior) dislocation may also occur.

Although this can usually be easily reduced back into place by manipulation with sedation, it may result in long-term problems of recurrent instability in younger patients if the supporting ligaments are pulled off. In these cases, physiotherapy may be required but, if this fails to stabilise the shoulder, then keyhole surgery may be required to fix the pulled-off ligaments. 

Sometimes, the shallow cartilage lip can come off the cup in young patients particularly in avid gym users. This is called a SLAP lesion and may cause pain, clicking and heaviness of the shoulder. These lesions are diagnosed using an MRI scan and do not normally heal. They frequently require an arthroscopy or keyhole surgical intervention to fix them.

The shoulder joint is a true ball-and-socket joint and the body sacrifices stability for mobility, making it the most easily dislocatable joint in the body

However, in older patients, a shoulder dislocation may avulse the rotator cuff muscles around the joint causing long term pain and weakness after the joint has been reduced. Injury to the shoulder may also result in a fracture. The neck of the humerus below the head is the most common place for the shoulder joint to break.

This is most commonly seen in elderly patients particularly with osteoporosis which weakens the bone. Most of these fractures may be satisfactorily treated with a sling and a physiotherapy programme. Most heal in six to eight weeks. Occasionally, the fracture may be more severe and may be in multiple pieces and displaced. In these cases, the patient may require fixation of this fracture using a plate and screws.

If the head of the shoulder joint is severely damaged, then this may require a half- or a full-shoulder replacement. These procedures are major operations but are ones which enable the patient to achieve a satisfactory functional range, although residual stiffness is common after these interventions due to soft tissue and surgical trauma.

Another consequence of shoulder injury is the development of a frozen shoulder. In this condition, the capsule and ligaments of the shoulder became swollen and inflamed and scar up, while becoming tight and short, thus causing pain and limitation of movement.

This is a very painful condition and may result even from a minor jar or fall and is more common in diabetic patients. The patient passes through three phases of the condition – freezing, frozen and thawing stage – and the natural history of the condition is for it to resolve within 18 to 24 months.

In the early stages, the condition may respond to painkillers, steroid injections and physiotherapy but when stiffness sets in, the patient may require a surgical keyhole release of the tight ligaments followed by an intensive course of physiotherapy.

Alistair Melvyn Pace, consultant orthopaedic surgeon