Synovectomy

Synovectomy refers to the removal of the synovial membrane (synovium) to treat synovitis or similar conditions affecting synovial joints.

Synovial joints are the commonly found joints in the body that allow movement in the adjoining bones. Types of synovial joints include hinge (elbows), ball and socket (shoulders and hips), pivot (forearm), and saddle (thumb and other fingers).

A pouch-like structure called a joint capsule surrounds a synovial joint. It is made of an outer, tough layer called a fibrous stratum and an inner, soft layer called the synovium. Between both the layers lies the synovial fluid to keep the joint lubricated. However, in synovitis, the synovium becomes inflamed and swells up, producing too much fluid. This fluid build-up contains an enzyme, which over time attacks the bone cartilages and damages the surface of the joint leading to pain and rigidity in the joint as observed in arthritis. Synovitis may occur due to overuse, injury to a joint, or it can be inherited.

A synovectomy is advised when medications fail to provide relief from the symptoms. Depending on the extent of damage, some parts of the synovium may be removed (partial synovectomy) or the synovium is removed entirely (complete synovectomy). Synovectomy performed before the deterioration of the bones and cartilages is likely to have a good outcome with better pain management.

A synovectomy may be performed on the synovial joints of the shoulder, ankle, hip, knee, wrist, elbow, and finger. Symptoms in a joint that may need a synovectomy include pain, swelling, and stiffness in the joints.

An individual with any of the following conditions is eligible for this surgery:

• Exudative synovitis (that produces fluid) in rheumatoid arthritis
• One or few joints are affected
• No response to treatments other than surgery
• Damage in the articular cartilage (cartilage that connects ends of two bones), not found on imaging test

Other indications for surgery include:

• Extreme pain
• Contractures (shortening and tightening of the joint) despite the several months of medical treatment
• Reduced movement

The surgeon may also recommend synovectomy in:

• Pigmented villo-nodular synovitis
• Synovial osteochondromatosis (rare non-cancerous condition of the synovium)
• Tenosynovitis (inflammation of a tendon and synovium) in case of rheumatoid arthritis

The doctor may not recommend synovectomy in people with:

• Acute inflammatory stage of joint disease
• Polyarticular arthritic conditions (affecting multiple joints)
• Dry synovitis (a type of idiopathic arthritis in children) 
• Systemic disease (a disease that affects the whole body)

Preparing for a synovectomy involves the following:

• Your doctor may perform tests such as blood tests, urinalysis, X-ray, nasal swab, ECG, and stress test.
• As a part of diagnosis and confirmatory tests, you will undergo an MRI and ultrasound of the joint.
• Inform your doctor if you have any heart disease or lung problems.
• Stop taking blood-thinning medications like aspirin three days before the surgery. These medicines may alter blood clotting.
• Inform the doctor if you take any steroid medicines like prednisone or cortisone. You can take them before and after the surgery.
• Before your surgery, eat foods high in fibre and rich in nutrients like vitamin C, iron, and calcium.
• Have light food the day before surgery as the bowel function will slow down under the effect of anaesthesia. This may lead to constipation following surgery.
• Stop smoking before the surgery and limit your alcohol intake.
• If you are overweight, recovery will be slower, especially if the weight-bearing joint (a joint like the knee or hip that bears the weight of the body) is affected. Therefore, maintain a healthy exercise regimen before the surgery to improve your flexibility, endurance, and stamina.
• You will be asked to sign a consent form prior to surgery allowing the doctor to perform the procedure.

A synovectomy can be performed in three ways, namely open, arthroscopic, and radiation synovectomy.

General anaesthesia (a sleep-inducing medicine) is administered before the surgery begins. An intravenous (IV) line will be placed in your arm to give fluids and medications. IV prophylactic antibiotics will be given before the surgery.

Open synovectomy

An open synovectomy can be performed in any joint. The steps to perform this procedure in the knee joint are discussed below:

• You will be asked to lie face down (prone position), and a tourniquet.will be placed on your thigh. It will apply pressure to your limb to slow the blood flow to the knee and help reduce bleeding during the surgery.
• The surgeon will make an S-shaped opening at the back of your knee, and expose the ligaments and tissues in the area.
• Next, he/she will dissect the posterior aspect of your knee (surface behind your knee), and remove the affected synovial tissue.
• The surgeon will make sure that the bleeding is controlled and then he/she will suture up the posterior part of your knee with absorbable stitches.
• Then, you will be moved on your back (supine position) with the thigh tourniquet in place.
• The surgeon will make an incision (cut) in the skin over your patella (kneecap) and remove the affected synovial tissue on the front. 
• He/she will close the tissues around the area with absorbable sutures, and place a compression bandage, which is to be retained for two weeks. A drainage tube is not required.

This is a complete synovectomy where the knee is approached through the front (anterior) and back (posterior).

Arthroscopic synovectomy

Arthroscopic synovectomy is carried out using three to five portals, namely anteromedial (front of the joint towards the middle), anterolateral (front of the joint towards the side), and lateral or medial suprapatellar (above the patella) portals, among others. A portal is the incision made in the skin through which instruments are inserted during the surgery. 

The surgery is performed in the following way:

• The surgeon will insert small tools, an arthroscope (a fibreoptic tool fixed with camera), and shavers into the joint through surgical portals. These tools will help in carrying out the surgery.
• He/she will use the images generated by the arthroscope camera as a guide during the surgery, and remove the affected synovial tissues from the centre and side of your knee, taking care to not remove any knee cartilages.
• After the procedure ends, a drain will be placed in your knee and suction will be applied to remove extra fluid from the area.
• Finally, the surgeon will wrap your knee in a thick bandage to immobilise it for three days.

Radiation synovectomy

Generally, radiation synovectomy is performed in children with haemophilia (a blood-clotting disorder). It involves the injection of a mixture that contains radioactive material. The following are the steps of this surgery:

• An anaesthesiologist will administer local anaesthetic (that makes the area numb) to you, and a healthcare practitioner will inject a radioactive isotope P32 into the joint to be operated. 
• This isotope reduces or retards the excess growth of the synovial tissues. In addition, it reduces bleeding, which is critical in people with haemophilia, and the risk of developing arthritis.
• The procedure takes about five minutes and does not require a hospital stay.

You can expect the following after surgery:

• You will be given pain medications such as morphine and paracetamol.
• You may have a bandage over your wound. Your nurse may teach you how to take care of the surgical site.
• Depending on the area of the surgery, compression bandages are used for three to five days after surgery. They work to immobilise the joint and the neighbouring area and facilitate healing.
• Under the supervision of a physiotherapist, direct and indirect bending, folding, and release exercises will be initiated to move the joints one or two days after surgery. You may also be started on continuous passive motion machines at the earliest to improve your movements.
• You will need to use a brace or splint that reduces sudden movements and lends support to the joint, especially while sleeping at night for the next six weeks after surgery. A rehabilitation therapist will be consulted to help you regain flexibility in the joint.
• The IV line will be removed once you can take enough fluids.
• Drains will be removed at the time of discharge.
• You will be discharged from the hospital in two days after open synovectomy.

You will need to take the following care at home:

• Take your pain medication as advised by the doctor. Feeling constipated or nauseous when on pain medicines is normal. 
• Do not drive while on pain medications.
• You may resume work after six weeks of surgery or as advised by the doctor. 
• Your doctor will suggest you to keep on exercises the joint to gain back your range of motion and strength.
• Avoid lifting heavy objects until your surgeon gives you the permission to do so.

Benefits of synovectomy:

• Reduces swelling and pain
• Improves the function of the affected joint
• Prevents further joint deterioration

When to see the doctor?

Contact your doctor immediately if:

• You experience swelling and tenderness at the site of the surgery 
• You have excessive pain at the surgical site
• You have a fever of 38.6°C (101^°F) or more
• The wound starts to drain fluids
• The joint mobility has reduced instead of improving

The following risks and complications associated with synovectomy may arise based on the surgical approach used and the joint operated on:

• Poor tissue healing
• Fragile and easily breakable bones
• Deep infections at the surgical site
• Chronic loss of joint movements due to structural changes at the joints (flexion contracture). Joints once bent are difficult to straighten
• Loose joints that bend more than usual (joint laxity) 
• Instrument breakage in case of arthroscopic synovectomy
• Neurovascular injuries (injury inbvolving nerves and blood vessels)

Regular follow-up visits with your doctor will be scheduled in a few weeks after your discharge from the hospital.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.