Revision shoulder replacement surgery may be advised to patients if they have one or more of the following conditions:

• Loosening of the prosthesis
• Infection in the prosthetic joint
• Worn out prosthesis
• Shoulder instability or a feeling of giving way
• Dislocation of the prosthesis
• Tears of the rotator cuff tendons due to trauma or wear
• Peri-prosthetics Fractures due to trauma
• Weakening of bone around the shoulder replacement, a process known as osteolysis (bone loss)
• Chronic progressive joint disease
• Increased pain in the affected shoulder
• Stiffness

Revision surgery may be needed soon after the original shoulder replacement surgery.

The following are reasons for short-term revisions: infection, implant loosening from failed procedure, or a mechanical failure

Reasons for long-term revisions (i.e several years after the original TSR): pain, stiffness, loosening due to wear of mechanical components, dislocation

There are several mechanisms and reasons for failure of implants in a patient who has undergone shoulder replacement.

• Wear and Loosening: Properly functioning implants depend on their appropriate fixation to the bone. Firm fixation is usually achieved by cementing the implant onto the bone. Some surgeons prefer biologic (non-cemented) fixation by using special coated implants that allow bone growth to provide firm fixation and stability.

  The firmly fixed implants, at initial shoulder replacement surgery, may become loose over time. Friction caused by the joint surfaces rubbing against each other wears away the surfaces of the implant and forms tiny particles that accumulate around the joint. In a process called aseptic (non-infected) loosening, the bond of the implant to the bone is destroyed by the body's attempt to digest these wear particles. During this process, the normal bone is also digested which weakens or even fractures the bones. This condition is termed as osteolysis.

  When the prosthesis becomes loose, the patient may experience pain, change in alignment, or instability. Aseptic loosening is a common mode of failure of shoulder implants.

• Infection:Infection is a serious and devastating complication of any surgical procedure. In partial or total shoulder replacement, the large foreign metal and plastic implants can serve as a surface for the bacteria to latch onto. They form a coating around themselves (biofilm) and become inaccessible to antibiotics. Even if the implants remain well fixed, the pain, swelling, and drainage from the infection make the revision surgery necessary. With current surgical techniques and antibiotic regimens, the risk of infection from total shoulder replacement is less than 1%.

• Fractures:The location, type and extent of the fracture will determine if revision surgery is needed. Periprosthetic fractures (fractures around the shoulder implants) can occur due to trauma. This disrupts the implant fixation or changes the stability of the implant which may warrant revision surgery.

• Instability:Instability occurs when the soft-tissue structures around the shoulder are unable to provide the stability necessary for adequate function during shoulder movements. Instability may be the result of increased soft-tissue laxity (looseness) and improper positioning or alignment of the prosthesis. Pain and/or a sense of “giving away” of the shoulder may alter shoulder function and require revision surgery.

• Patient-Related Factors:Patient’s Age, activity levels, surgical history and medical co-morbidities can contribute to implant failure. Younger, more active patients have a higher rate of revision than older patients. Patients with previous shoulder surgeries are also at higher risk for infection and implant failure.

After the decision for revision shoulder replacement is made, standard assessments are performed, including new shoulder x-rays, blood tests, and possibly other imaging modalities like bone scans, CT scans, or Magnetic Resonance Imaging (MRI) studies.

X-rays may demonstrate a change in the position or condition of the components and also shows the quality of the bone. CT scans with 3D reconstruction helps in assessing the bone loss, the best areas for drilling and placement of implants especially the glenoid implant. MRI also helps to determine the cause, location, and the amount of bone loss before surgery. It also gives information about the quality of the soft tissues around the shoulder joint, especially the rotator cuff tendons.

Aspiration of the shoulder (joint fluid removed with a needle) may be required if infection is suspected. This aspirated fluid will then be sent to a laboratory for analysis to identify the specific type of organism causing infection.

Steps involved in a revision shoulder replacement:

• Most Revision Shoulder Replacements take longer to perform than primary procedures (about two to three hours).
• It may involve the replacement of one or all of the components.
• The surgery is performed under general anaesthesia and an interscalene block.
• The patients are seated in a beach chair position on special tables.
• Surgical scrubbing and painting and draping are done.
• The surgeon makes an incision over the shoulder, preferably through the old scar, to expose the shoulder joint.
• Fluid samples and tissue samples are taken for culture and sensitivity tests to identify organisms causing infection. The condition of the rotator cuff tendons is checked. If it is intact and of good quality, then the decision for standard revision shoulder replacement is made.
• The first step is removal of the implants. The old humeral component of the shoulder prosthesis is removed first using special cutting devices.
• The humerus then is prepared to receive its new prosthesis. In some cases, the damaged bone gets removed and bone grafts may be used to reconstruct the lost bone and strengthen the humerus. In extensive bone loss cases, long supporting rods (intra-medullary stems) are attached to the implant to provide extra fixation to the implant in lower humerus and stability to the shoulder joint.
• Next the glenoid component along with the old plastic liner is removed.
• The remaining bone of the glenoid is inspected. If any bony defects are seen then these can be filled up with iliac crest bone graft before preparing it for accepting the revision glenoid implant.
• The glenoid implant is then implanted with or without bone cement. For uncemented glenoid implants, special screws are used for additional stability.
• The humeral trial implants are then inserted. Appropriate size shoulder ball is attached, and the joint is reduced.
• The surgeon then checks for arm length, stability of the shoulder joint and its range of movement. X-rays are also taken to confirm the length of the humeral implant, its position and alignment. Once everything is deemed satisfactory, the trial implants are removed.
• Then the real humeral implant (stem) is inserted with or without cement as per bone quality. The depth of insertion into the humerus is as per the trial information or gets decided under x-ray control. The appropriate size humeral head is applied over the humeral stem after re-trials and the joint is relocated.

• In cases with poor quality rotator cuff tendon or massively torn tendons, the surgeon decides to proceed with a Reverse Shoulder Replacement and uses appropriate techniques and implants.

• Hence operating surgeon needs to have all types of shoulder implants and inventory ready in the operation theatre which enables him to use the most appropriate revision implants for the patients. This ensures best possible outcome for the patient.
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• At the end of the surgery, the joint is thoroughly washed out, any bleeding points are secured and sealed with cautery to avoid bleeding.
• The shoulder wound is then closed in layers after keeping a suction drain inside to drain out excess blood from the shoulder joint.
• Sterile dressings and a compression bandage pad are applied. Patients are also provided with a new shoulder sling for support.

Post-operative care after shoulder revision surgery is very similar to the care of a primary shoulder replacement. This includes a combination of pain medication and blood management as necessary. Physiotherapy is started after few hours post-surgery to encourage finger movements along with ankle and toe movements. Appropriate antibiotics and some method of blood clot prevention (DVT Prophylaxis) will be continued in the postoperative period.

In most cases, physiotherapy will be initiated within 24 hours of the procedure. Gentle pendulum exercises for shoulder, static shoulder, elbow and hand exercises are started.

Patient’s hospital stay can be between 1 to 2 days depending upon the complexity of the case. They need to be under care of a physiotherapist on a regular basis.

Wound healing is check after 10 to 12 days. Shoulder sling is discarded after 4 to 6 weeks.

Recovery time after revision shoulder surgery is variable depending upon several factors. Patients should be forewarned about this recovery duration which may be 4 to 6 months or longer in some cases.

Any surgery can have potential complications. The complexity of revision shoulder joint replacement increases the chance of surgical complications which are similar to the primary shoulder replacement.

Possible complications include:

• Infection
• Bleeding
• Damage to nerves or blood vessels
• Intra-operative fractures - occur during removal of the old implants or the insertion of new ones
• DVT (Deep Venous Thrombosis) or blood clots
• PE (Pulmonary Embolism)
• Implant loosening
• Dislocation of the new implants. (Higher compared to primary surgery).
• Shoulder Stiffness
• Shoulder region swelling
• Failure to get complete range of motion in the shoulder
• Scar hypertrophy