Shoulder replacement, Shoulder arthroplasty.
Hip and Knee replacement operations have become common and many people will know someone who has undergone this type of surgery. Shoulder replacement surgery is a much less common operation but can be just as successful in relieving the pain associated with an arthritic shoulder.
The main shoulder joint (the Gleno-Humeral joint) is a ball and socket joint. The proximal Humerus (upper arm) forms a hemisphere that forms a joint with a shallow socket, the Glenoid of the Scapula. The two surfaces are covered in specialised Hyaline cartilage. This produces a very smooth low friction joint that glides and moves freely without discomfort. This joint is extremely effective and provides the largest range of movement of any joint in the body. However, because of the stresses to which the joint is subjected it is vulnerable to wear and injury.
The Gleno-Humeral joint surface can become damaged and painful. This is often associated with stiffness or loss of movement. The stiffness effects both active movement (produced by voluntary contraction of the muscles around the shoulder) and passive movement (produced when the arm is moved by someone else). The pain is often felt over the upper arm or deep within the shoulder. There may be pain in the Trapezial and Para-scapular regions typically associated with stiffness and resultant compensatory movements.
There may be associated crepitus (grinding and cracking of the joint) on movement. However, it should be noted that most noises felt or heard around the shoulder are not associated with arthritis or joint damage and these are not in themselves unduly concerning unless they are associated with pain.
Link to additional information on Shoulder / Glenohumeral arthritis.
Shoulder replacement may be considered for a shoulder joint where the articulating surface has become damaged or worn and is associated with pain not relieved by conservative or non-operative treatment.
These conditions include:
Osteoarthritis (wear and tear arthritis)
Rheumatoid arthritis (inflammatory arthritis)
Post traumatic arthritis (damage to the shoulder following an injury or fracture(break).
Avascular necrosis (damage to the joint surface and bone as a consequence of an interrupted blood supply).
Rotator cuff arthropathy (failure of the rotator cuff tendons with subsequent arthritis).
Severe fractures of the shoulder.
Non operative management treatment for shoulder arthritis or degeneration include:
Analgesia and Anti-inflammatories.
Anti-inflammatory medication (eg: Diclofenac, Ibuprofen and Voltarol) and analgesia (pain killers eg: Paracetamol and Codeine) may provide significant relief of symptoms.
Physiotherapy may provide relief of symptoms by maintaining range of movement and muscle strength. Heat may be helpful for pain and or ice packs useful for swelling. As the joint degeneration progresses rehabilitation may become less effective.
Steroid or Cortisone injections may be provided into the Gleno-humeral (shoulder) joint. These may provide symptomatic relief but the effect is variable. There is some concern regarding an increased risk of infection in joint replacement following shoulder surgery (see section on steroid injections).
The diagnosis may be apparent to your surgeon or doctor from the history and examination.
Plain radiographs (Xrays) are required to confirm the diagnosis.
Scans may be necessary particularly to image the rotator cuff muscles (Ultrasound or MRI, Magnetic Resonance Imaging) and any associated damage or loss of bone around the joint (CT, Computerised Tomography).
The surgery is typically undertaken with the patient asleep with a nerve block to provide additional pain relief.
Incision and Dressings:
Shoulder arthroplasty or replacement is typically an open procedure. An incision or scar approximately 5 to 8cm in size is made over the front of the shoulder.
This is typically closed with an absorbable suture under the skin. Paper Butterfly Stitches (SteriStripsTM) are usually used and the wound covered with padding and a splash proof OpsiteTM dressing.
There are several different types of shoulder replacements. The typical Total shoulder replacement involves replacing the arthritic joint surfaces of both the Humeral head (ball) and the Glenoid (socket) with a highly polished metal ball and a plastic socket. The replacement may be secured using special acrylic bone cement or as an un-cemented, press-fit. It may be decided not to replace the socket, a Hemi-arthroplasty, or that the Humeral head does not need to be removed and can be resurfaced with a metal cap, resurfacing arthroplasty. If the rotator cuff tendons are torn or the muscles are not functioning (eg: after a fracture) then it may be necessary to undertake a Reverse Geometry shoulder replacement. A reverse replacement involves securing a ball to the Glenoid (or socket) and a socket to the Humeral shaft in place of the Humeral head.
The shoulder joint is entered by releasing the Subscapularis tendon at the front of the shoulder by dividing the tendon or detaching the Lesser Tuberosity to which it attaches from the rest of the Humerus.
The Humeral head surface is then exposed and assessed. If the shape of the humeral head remains reasonably preserved then a resurfacing replacement may be undertaken with the head being preserved. If there is significant damage to the Humeral head then the head is removed and replaced.
The Glenoid or socket may also be prepared and resurfaced with a plastic socket.
Once the joint has been replaced the Subscapularis is then secured back in place.
A small drain or tube may be left to in place overnight following the surgery to drain away excess bruising.
There are many different types of shoulder replacements and your surgeon will choose one that they feel is most appropriate for you.
The following video is an animation of one particular type of shoulder replacement and serves as an illustration of what may be involved.
Please select the following link to view the .wmv file version if you do not wish to install QuickTime:
Following the surgery you will wake with your arm in a sling. The hand and arm are likely to be numb for 24-48 hours following the surgery because of the pre-operative anaesthetic injection.
The drain and IV line (drip) will typically be removed the following day. Once you are comfortable and well you may then be discharged home.
You will usually have been seen by a Physiotherapist while in hospital and will be given clear instructions regarding you rehabilitation. Follow up arrangements with the Physiotherapists will normally be made before or soon after your discharge.
The success of the operation is dependent on the careful adherence to the rehabilitation guidelines. The arm is supported by a PolyslingTM for 3-6 weeks. Typically it takes 6-8 weeks before it is safe to drive a care (please see general rehabilitation guidelines). In general you should not lift anything heavier than a glass of water with the operated arm for 6 weeks following the replacement surgery.
Risks of Surgery:
All operations are associated with a degree of risk but significant complications associated with a shoulder arthroplasty are uncommon. The following risks are those that are serious or most commonly reported in the literature.
Infection (1%). Infection in shoulder surgery is uncommon, particularly in keyhole (arthroscopic) surgery. It is potentially very serious complication and all steps should be undertaken to minimise the risk. Antibiotics are typically given before surgery is commenced to reduce the risk. If an infection were to develop it is typically a superficial infection, that can be treated with oral antibiotics. Rarely does an infection develop that requires re-admission to hospital and surgery to wash the infection out. Rarely a deep infection may develop requiring surgery to remove the replacement. An extended course of antibiotics is then usually required before consideration can be given to re-siting the replacement.
Anaesthetic Risks (Anaestheic complications are rare but include Heart Attack (Myocardial Infarction, MI), Stroke (Cerbero-Vascular Accident, CVA) and a clot in the leg (Deep Vein Thrombosis, DVT) or lungs (Pulmonary Embolus, PE).
Damage to nerve or blood vessels (Neuro-Vascular Damage) (<1%). Damage to nerves or blood vessels are rare. Damage to the axillary nerve may occur as it passes close to the joint. Damage to this nerve may result in weakness and difficulty bringing the arm out to the side (abduction).
In the same way that a native shoulder can dislocate following a trip and fall a shoulder replacement may dislocate or become unstable. Further surgery may be required to stabilise the shoulder.
Lifespan of the prosthesis.
Shoulder replacements like all artificial joints are subject to wear. As such further surgery may be required to revise and replace the components. The anticipated lifespan of the replacement is considered to be typically 10-15 years but will depend on a number of factors including the age of patient and the functional demands placed upon it.
After the surgery and a period of immobilisation the shoulder is likely to be stiff. This stiffness should improve with time and graduated rehabilitation. The range of movement is usually improved following shoulder replacement surgery improvement is not certain.
Tears of the tendons which stabilise the shoulder joint may occur in a normal shoulder. If the tendons fail after a shoulder replacement there is an increased risk of instability and a suboptimal outcome. Occasionally further surgery is required to repair the tendon or the type of shoulder replacement may need to changed.
Because of potential weaknesses in the bone and the change in the stresses around the shoulder it is possible to sustain a fracture or break in the bones around the shoulder either during the surgery or after the surgery typically following a fall or injury. Fractures are reported to occur in approximately 5% of shoulder replacements. Occasionally further treatment is required.