Shoulder Conditions

Shoulder replacement is an elective operation, and the decision is driven by how much the shoulder is limiting your life — night pain, loss of rotation, inability to reach overhead or behind the back — rather than by the appearance of the X-ray alone. Nonoperative treatment is exhausted first, and in younger patients joint-preserving options are considered before an implant is recommended.

When replacement is the right answer, the choice between an anatomic and a reverse replacement is made from the rotator cuff and the glenoid, not from age alone. Every case is planned from a dedicated CT scan using three-dimensional software, so glenoid version, inclination, and bone loss are measured before the operation and the implant position is decided in advance rather than estimated in the operating room.

Bone is preserved wherever possible — stemless or short-stem humeral components and augmented glenoid components allow correction of wear patterns without bone grafting in most shoulders, and leave better options behind should a revision ever be needed decades later.

Two questions decide almost every shoulder arthritis operation: is the rotator cuff functioning, and is there enough glenoid bone to support a socket component. An anatomic replacement reproduces normal shoulder mechanics but depends entirely on an intact cuff; a reverse replacement changes the mechanics so the deltoid — not the cuff — powers elevation.

Why the distinction matters: the rotator cuff is the deciding factor. Placing an anatomic replacement in a shoulder with a failing cuff leads to early loosening of the glenoid component and pain, while a reverse replacement placed in a shoulder with a healthy cuff gives up rotation that could have been kept. This is why an MRI of the cuff and a CT of the glenoid are obtained before the plan is finalised.

Cuff intact Anatomic total shoulder

Left: bone-on-bone glenohumeral arthritis with joint space loss and inferior spurring. Right: the same shoulder after anatomic replacement, with the humeral head and glenoid resurfaced and the joint line restored.

Through a front (deltopectoral) approach, the subscapularis tendon is taken down and later repaired, the arthritic humeral head is removed, and spurs are cleared. The glenoid is prepared to the planned version and a polyethylene socket — augmented on one side when there is posterior wear — is cemented or press-fit in place. A trial ball is used to balance soft-tissue tension and confirm motion before the final stemless or short-stem component is seated. Because the subscapularis repair must heal, active internal rotation and pushing are protected for about six weeks.

Cuff deficient Reverse total shoulder

After reverse replacement: the glenosphere is screw-fixed to the glenoid and the socket sits on the humerus, so the deltoid — not the rotator cuff — powers elevation.

A baseplate is fixed to the glenoid with a central post and peripheral screws — augmented or bone-grafted when wear has been severe — and a glenosphere is attached. The humerus is prepared for a socket-bearing component, and the amount of lengthening and lateralisation is set to tension the deltoid without over-tightening the arm. The subscapularis may be repaired or left unrepaired depending on the design and tissue quality. Elevation is often possible early, but combined extension, adduction, and internal rotation — the position that levers the implant out — is avoided for the first six weeks.

Both operations are usually performed under a regional nerve block with light general anaesthesia, take roughly one and a half to two hours, and are increasingly done as a same-day or single-overnight stay in appropriately selected patients.

Shoulder replacement is among the most reliable operations in orthopaedics for pain relief, but it is a major procedure with real risks that are worth weighing: infection, bleeding, blood clots, nerve injury (most often a temporary axillary or musculocutaneous nerve stretch), periprosthetic fracture of the humerus or glenoid, and anaesthetic complications. Implant-specific risks include loosening of the glenoid component over time, polyethylene wear, and — after an anatomic replacement — later rotator cuff or subscapularis failure, which is the most common reason such a shoulder is converted to a reverse. Reverse replacements carry their own profile: dislocation, acromial stress fracture, scapular notching, and persistently limited internal rotation. Stiffness, incomplete pain relief, and asymmetry in strength between sides also occur. Overall revision rates are low, but the risk is higher in younger, heavier, and higher-demand patients and in revision surgery.

Pain relief. The most predictable result of either replacement. The large majority of patients report substantial or complete relief of arthritis pain, and restored sleep is often the change patients notice first.

Motion and strength. Anatomic replacements generally regain the best rotation and the most natural feel. Reverse replacements reliably restore forward elevation but often leave internal and external rotation short of normal, which matters for reaching behind the back and fastening clothing.

Durability. Registry data show roughly 90–95% of anatomic replacements and about 90% of modern reverse replacements still functioning at ten years, with the majority lasting considerably longer. Younger and higher-demand patients should expect a higher lifetime chance of revision.

Follow-up visits at six weeks, three months, one year, and periodically thereafter track motion, strength, and implant position on X-ray. Lifetime activity guidance — avoiding repetitive heavy overhead lifting and impact loading — protects the implant and is discussed individually.