Reverse Shoulder Replacement

A reverse shoulder replacement surgically swaps the ball and socket positions using prosthetic implants.
Dr Phillip Markham, a shoulder surgeon in Gosford, Wollongong and Sydney, frequently performs this procedure, which involves placing the ball on the shoulder blade and the socket on the upper arm bone.
Unlike a traditional replacement, a reverse shoulder replacement doesn’t rely on the rotator cuff for stability, making it suitable for patients with cuff tear arthropathy, severe osteoarthritis, complex fractures, or failed previous replacements.
The procedure takes 1.5–2 hours under general anaesthetic.
Recovery spans around six months, beginning with a sling for several weeks followed by physiotherapy.
Risks include dislocation, infection, and nerve damage.
This procedure accounts for 72.7% of all primary total shoulder replacements performed in Australia.

A reverse shoulder replacement (that involves reversing the placement of the prosthetics used in a traditional shoulder replacement) has several advantages over an anatomic shoulder replacement.

“The reverse replacement produces an inherently stable joint that is not reliant on the integrity of the rotator cuff for joint stability and movement, unlike the native shoulder or an anatomic replacement. The deltoid muscle and other large muscles that span the shoulder joint are biomechanically advantaged in a reverse shoulder configuration, aiding with joint stability and strength and easier, pain-free movement,” says Dr Markham.

Reverse shoulder replacement is indicated for the treatment of multiple conditions where an anatomic shoulder replacement may not be appropriate.

These conditions can include:

• Osteoarthritis with significant structural bone loss (that precludes implantation of a well positioned anatomic shoulder replacement)
• Cuff tear arthropathy, where arthritis has developed due to large, long-standing or chronic rotator cuff tears
• Long standing and large symptomatic tears of the rotator cuff that cannot be repaired with surgery in an older patient
• Revision joint replacement with loss of structural bone
• Complex shoulder joint fracture that is irreparable
• Avascular necrosis of the humeral head, a condition with a loss of blood supply and accelerated arthritis
• Some cases of shoulder tumours or chronic dislocations

Reverse shoulder replacements can also be performed if a traditional shoulder replacement was unsuccessful, or if shoulder pain persists even with non-surgical intervention.

“Both surgeries are used to relieve shoulder pain, but only a reverse shoulder replacement is able to restore movement and function to individuals with severely torn rotator cuffs. Consult with your surgeon to find out what is right for you,” says Dr Markham.

A reverse shoulder procedure is typically a 1.5–2 hour procedure performed under general anaesthetic, with a local anaesthetic also administered around the shoulder.
During the procedure, Dr Markham will make an incision anteriorly over the shoulder, carefully moving aside surrounding muscles and tissues to expose the shoulder joint.
He will then remove the humeral head (the damaged ball part of the joint which he will retain for use as a bone graft for the socket) and the damaged socket (glenoid) and insert the metallic and prosthetic components.
In a reverse shoulder replacement, the metal ball is attached to the shoulder blade (scapula) in place of the glenoid, often with a bone graft and multiple screws.
At the humerus, a metal stem is implanted into the bone with an attached plastic socket to form the cup.
He will then reduce the joint at the correct tension to achieve stability to improve functionality before closing the incision.

Recovery from a reverse shoulder replacement is a two-step process that takes about six months.
For a few weeks following surgery, a sling is needed to keep your arm immobilised. 
After this, physiotherapy is recommended in order to achieve the full range of movement that the reverse shoulder replacement allows.
A physical therapist may assign small exercises to perform throughout the day to help strengthen the shoulder muscles and speed up recovery.

With a complex procedure such as reverse shoulder replacement surgery, there is a possibility of complications. These can include:

• Dislocation of the prosthetic shoulder joint
• Infection
• Blood loss
• Nerve damage
• Anaesthetic complications
• Shoulder fracture
• Change of shoulder contour

Less common risks of surgery and anaesthetics include:

• Blood clots in the legs
• Heart attack
• Stroke

“All surgeries carry associated risks. We will explain the risks relevant to your procedure and the steps we take to minimise them,” says Dr Markham.

Apart from the initial restrictions with movement that occur in the immediate 4 weeks after surgery, it is not uncommon for patients to lose some internal rotation after a reverse shoulder replacement (reduced movement with reaching behind their upper back, such as limiting the ability to perform tasks such as fastening a bra).

Patients most suitable for reverse shoulder replacement include:

• Patients with severe osteoarthritis
• Patients with rotator cuff tears and arthritis
• Patients who have previously undergone shoulder replacement surgery and found the results unsatisfactory