Shoulder Replacement

The shoulder is a ball and socket joint. The rounded head of the upper arm bone, the humerus, sits against a shallow socket on the shoulder blade called the glenoid, and a group of tendons known as the rotator cuff keeps the ball centred and helps lift and turn the arm. In shoulder replacement the damaged joint surfaces are removed and replaced with an implant. In an anatomic total shoulder replacement, a metal ball fixed to a short stem in the humerus moves against a plastic socket fitted onto the glenoid, copying the natural shape. In a reverse total shoulder replacement the positions are swapped: a metal ball is fixed to the shoulder blade and a plastic cup to the top of the humerus. This changes the mechanics so the large deltoid muscle can raise the arm without a working rotator cuff. A partial replacement, or hemiarthroplasty, replaces only the ball and is now used for a narrower group of patients.

Shoulder replacement is considered when pain, stiffness and loss of function persist despite a sustained trial of painkillers, anti-inflammatory medicines, steroid injections, activity changes and physiotherapy. The most common reason is osteoarthritis, in which the cartilage wears away and bone rubs on bone, followed by inflammatory arthritis such as rheumatoid arthritis. An anatomic replacement suits arthritis when the rotator cuff is still intact and working. A reverse replacement is generally chosen for cuff tear arthropathy, the arthritis that develops after a large long-standing tear, for a massive cuff tear that cannot be repaired, for some complex fractures of the upper arm in older adults, and for revision of an earlier replacement that has failed. Other causes include loss of blood supply to the head of the humerus, called avascular necrosis, and arthritis after an old injury. Night pain that disturbs sleep and difficulty reaching overhead or behind the back are typical reasons to discuss surgery.

The operation is usually done under general anaesthesia, often combined with an injection of local anaesthetic around the nerves at the base of the neck, called an interscalene block, which numbs the shoulder for many hours afterwards. You are positioned half sitting, and the surgeon most often reaches the joint through an incision of about 10 to 15 centimetres at the front of the shoulder, working between the deltoid and chest muscles. One of the front rotator cuff tendons is detached to open the joint and repaired at the end. The worn head of the humerus is trimmed and the glenoid surface prepared, then trial components are tested for size, tension and stability before the final implants are fixed, either with bone cement or by a press fit that lets bone grow onto the implant surface. Many teams plan the position of the components in advance on a three-dimensional CT model. The wound is closed, the arm placed in a sling, and the procedure usually takes about 1.5 to 2.5 hours.

A good candidate has persistent shoulder pain and limited movement confirmed by imaging, has tried non-surgical treatment for several months, is fit enough for anaesthesia and is ready to commit to months of exercises. Age alone is not a barrier, although younger, very active people need a frank discussion about implant wear and the chance of a future revision. The choice between anatomic and reverse designs depends largely on the rotator cuff, which is assessed with an MRI or ultrasound scan, and on the shape and bone stock of the glenoid, measured on a CT scan. Before surgery you will have blood tests, an ECG where needed and a review of your medicines; blood thinners may need to be paused and diabetes brought under good control. Any infection, including dental or skin problems, should be treated first, and stopping smoking helps the wound and bone heal. For international patients, X-rays, scan images and reports can usually be reviewed remotely so the plan is largely agreed before travel.

Most people stay in hospital for one to three nights, and the physiotherapist starts gentle movements, such as pendulum swings and assisted lifts, from the first or second day. The arm is kept in a sling for about four to six weeks, mainly to protect the repaired tendon, and you should not drive, lift or push with that arm during this time. Active exercises begin once the tendon has healed, and strengthening usually follows from around three months. Most daily tasks become comfortable within two to three months, while movement and strength keep improving for 6 to 12 months. For travel, plan to stay about 10 to 14 days so the wound can be checked, stitches or clips removed if needed and the exercise programme taught in person. Afterwards a physiotherapist near home continues the programme from a written plan, with remote follow-up and X-rays at agreed intervals.

Shoulder replacement is an established operation that gives reliable pain relief for most patients, but it carries real risks worth weighing before you decide. Infection is uncommon but serious and may need further surgery. The joint can become unstable or dislocate, a risk somewhat higher after reverse replacement in the early months. Other complications include stiffness, a fracture of the bone around the implant, nerve injury that is most often temporary, wound problems and blood clots, which are less frequent than after hip or knee replacement. Over the years the plastic socket of an anatomic replacement can wear or loosen, and the shoulder blade under a reverse implant can show a small notch on X-rays; either may eventually call for revision. Most patients report much less pain and better sleep within weeks. Anatomic replacements often regain a good range of movement, while reverse replacements reliably restore lifting of the arm but may leave some limitation in turning the arm outwards or reaching behind the back. Many implants function well for 10 years or more.