Reverse Shoulder Replacement

Normal shoulder function is a necessity, may it be for basic day to day activities or recreation and sports. Persistent shoulder pain can make even simple daily activities difficult such as combing your hair, reaching a shelf, getting dressed or sleeping comfortably.

Shoulder arthritis leads to constant pain and functional limitations. More than primary osteoarthritis, arthritis or arthropathy occurring after a tear of rotator cuff muscles is much more common. These patients do not benefit from routine anatomical shoulder replacement.

In such patients, invention of Reverse Shoulder Arthroplasty (RSA) has come in as a boon. It not only allows relief from pain but makes it possible to return to almost all normal activities.

What is ‘Reverse’ Shoulder Replacement?

Reverse shoulder arthroplasty is a new and advanced type of shoulder replacement surgery. In a normal shoulder joint, the ball is on the arm bone and the socket is on the shoulder blade.

In reverse shoulder arthroplasty, this arrangement is reversed:

• A ball is fixed to the shoulder blade

• A socket is attached to the arm bone

This special prosthesis design allows one to regain shoulder movements despite non-functional rotator cuff muscles.

Why is this new design necessary?

To dive into some details, the rotator cuff is a group of four muscles that keep the shoulder joint stable. With ageing or after a fall, when the rotator cuff tendons are completely torn and retracted beyond repair, the shoulder becomes unstable and weak, leading to pseudo-paralysis of the arm.

In such cases, a regular shoulder replacement is not helpful because it depends on healthy rotator cuff muscles for stability.

Reverse shoulder arthroplasty solves this problem by changing the shoulder joint biomechanics. After surgery, the deltoid muscle can function normally due to the joint's altered centre of rotation, allowing patients to regain shoulder movement without arthritis pain.

Who can benefit from Reverse Shoulder Replacement?

The following clinical scenarios are the ideal indications:

1. Rotator cuff tear arthropathy

This is a condition in which a long-standing rotator cuff tear leads to joint arthritis and shoulder joint collapse. Patients have severe pain and present with pseudo (false) paralysis of the arm.

2. Complex shoulder fractures in elderly patients

In older patients above the age of 65-70 years with comminuted 4-part fractures of the upper arm bone (proximal humerus), RSA provides more predictable shoulder function compared to fracture fixation and partial shoulder replacement (hemiarthroplasty).

3. Severe shoulder osteoarthritis with bone loss

In certain advanced cases of primary osteoarthritis with poor bone quality or bone loss, reverse shoulder replacement yields better results than conventional shoulder replacement.

4. Failed previous shoulder surgery

In case of a failed previous shoulder fracture fixation, rotator cuff surgery or even a partial or total shoulder replacement, RSA offers the best outcomes as the last resort.

What tests are performed to decide on and plan this surgery?

A detailed assessment is necessary, which includes:

• Clinical examination of shoulder movement and strength

• X-rays: to check the severity of arthritis and bony anatomy

• CT scan: to understand bone size, shape and extent of bone loss, to calculate the prosthesis size

• MRI: to assess the rotator cuff muscles and other soft tissues around the joint

Your age, activity level, overall health, and expectations are carefully considered before planning surgery.

What is done during the surgery?

Reverse shoulder replacement is performed under general anaesthesia, with an additional nerve block to negate the pain immediately after surgery.

During the operation:

1.   The damaged joint surfaces are removed

2.   The metal ball is fixed to the shoulder blade bone (scapula)

3.   The socket component is placed on the arm bone (humerus)

4.   The joint is checked for adequate stability and smooth movements

The surgery typically takes 1.5 to 2 hours.

How is the recovery after surgery?

1. Hospital Stay

The patient stays in the hospital for 2 to 3 days after surgery. Pain is controlled with medications, and gentle exercises are started from day 2.

2. Sling Use

The operated arm is supported in a sling for about 4 weeks to allow rest for the tissues during early healing.

3. Physiotherapy

Supervised rehabilitation is a key part of the recovery:

• Early phase: gentle assisted movements

• Late phase: active movements and strengthening exercises

Most patients are able to perform routine daily light activities by 6 to 8 weeks, with continued improvement over the next 9 to 12 months.

What results can be expected?

Reverse shoulder arthroplasty is highly successful in relieving pain and improving function. Most patients experience:

       - Significant reduction in shoulder pain

       - Improved ability to lift the arm

       - Better independence in daily activities

       - Improved sleep quality

While the shoulder may not feel completely “normal,” the improvement in comfort and function is often dramatic.

What are the possible complications?

As with any surgery, reverse shoulder replacement has the following risks involved:

• Infection

• Shoulder dislocation

• Nerve or blood vessel injury

• Loosening of the implant over time

With modern implants and advanced techniques, these complications are quite rare.

How long does the replaced joint (prosthesis) last?

Modern reverse shoulder replacement designs are super advanced and designed to last 15 to 20 years or even longer. Unlike the knee, the shoulder is a non-weight-bearing joint, the prosthesis longevity is better. Regular follow-ups with the surgeon ensure long-term success.

To conclude..

Reverse shoulder replacement has revolutionised the management of painful rotator cuff tear arthropathy or failed other primary surgeries.

Due to its innovative design, it supersedes over all other surgical modalities both biomechanically and clinically.

If you are suffering from a long-standing shoulder pain, weakness or restriction of movements, consult Dr. Ajinkya Achalare at ArthroSports Speciality Orthopaedic Clinic at Dadar, Mumbai, to find out the cause and the right treatment approach tailored for your needs.