Knee Procedures / Total Knee Replacement

The knee is a hinge type of joint. A total knee replacement (TKR) is a surgery that replaces a diseased knee joint with an artificial metal or plastic replacement parts called the ‘prostheses'.

What to expect as a patient of TKR

You are examined by me and, if suitable, a decision to proceed with TKR surgery is made. This is a co-operative decision between you, me, your family and your local doctor. The whys and wherefores of this surgery are discussed in detail with you. Main benefits to be expected of this surgery are

Admission is one day prior to the scheduled date of operation around 11am at the front office. If you are on blood thinner tablets, stop those tablets 7 days before surgery.

Surgery

The surgery involves correction of the deformity, removal or excision of diseased joint surfaces and replacing them with man-made artificial joints called prostheses. Many arthritic knees are bowed or knock-kneed. A total knee replacement will correct this deformity. Once the two metal components are fixed to the bone, a plastic insert is placed on the tibial surface. This plastic acts as the shock absorber. The plastic allows the low friction movement to occur. The plastic may either be fixed or mobile depending on the type of prosthesis.

Replacement of the kneecap is controversial. I am aware of the debate but I normally do not replace the kneecap. Following insertion of the components the wound is closed usually with absorbable sutures inside and a drain is inserted. Skin usually gets removable sutures. The operation takes about 60-90 minutes

Post Operation

Risks and Compliactions of Knee Replacement Surgery

Surgery is not a pleasant prospect for anyone, but for people with arthritis, it could mean a major difference between leading a normal life and compromising with the quality of life, putting up with a debilitating condition.

Total knee replacement is one of the most successful procedures in orthopaedic surgery, and, evidence shows that the benefits of total knee replacement surgery far outweigh the potential disadvantages. However, as with any major surgery, there are potential risks involved. It is important that you are informed of these risks before the surgery takes place.

Anaesthetic complications. As anybody undergoes general or regional anaesthesia, there are risks associated with it although, with technology as it is today, the chances of having a major anaesthetic complication are rare. The risks, of course, are magnified if you have abnormal general medical conditions of your vital organs such as heart, lungs and kidneys. Therefore a complete evaluation of those systems has to be performed before you are taken to the operating theatre.

Blood clots (Deep Vein Thrombosis). These can form in the calf muscles and can travel to the lung (pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify your doctor. Being fully aware of the debate, I take full precautions and I use aspirin 75 mg daily for four weeks, after surgery, as a prophylactic dose.

Infection. Superficial wound infections may occur early on and deeper infections can occur at a later stage. The incidence of infection is less than 1%. Infections are usually treatable with antibiotic treatment. You are given antibiotics before the operation and for the first two days to prevent infections from happening. Very rarely, if a joint has a deep infection that cannot be controlled with antibiotic therapy, the joint requires removal and a second joint re-implanted at a later stage.

Leg length discrepancy. It is not unusual for there to be up to 1cm leg length discrepancy following a total knee replacement. This is quite easily tolerated.

Fractures. Very rare at the time of surgery and this is usually treated immediately. It is not uncommon to fracture around the replacement in elderly patients at a later stage.

Loosening of the prostheses. Over a period of time the prostheses may loosen if the bone does not grow into it sufficiently or if the bearing surface wears out to produce areas around the prostheses, leading to loosening. Should a prosthesis loosen, then it can be revised. If only the bearing surface wears out, then usually only the bearing surface requires revision which is a much smaller operation.

Damage to nerves and vessels. It is unusual to damage any major nerves or blood vessels following a knee replacement. However nerve palsy can develop if the nerve is stretched during surgery, especially if surgery involves correction of severe deformities.

Haematoma. Occasionally a bleed may occur around the knee joint following the operation that may require drainage. Spontaneous recurrent bleeding episodes after total knee replacements have been reported in the literature.

Scarring. Some patients tend to scar more than others and it may be that the scar that you have will be quite thickened (keloid).

Long-term bruising and swelling. Occasionally the operated leg may remain bruised and swollen for a number of months and the knee may appear bigger than the un-operated knee for a long time, but in general this tends to resolve.

Numbness around the wound. It is quite possible to get numbness around the wound. It may be temporary or permanent but, this should not affect the function of your knee in any way.

Stiffness in the knee . Ideally your knee should bend beyond 100 degrees but on occasion the knee may not bend as well as expected. Sometimes manipulations  are required, this means, going to theatre and under anaesthetic the knee is bent to achieve more flexion.

General advice after knee replacement surgery

You should have a regular check every year with an x-ray.

If you have had any major bowel, bladder or dental surgery, antibiotic cover should be given prior to the surgery.

Metal prostheses can activate security alarms at the airports.