In knee replacement the damaged/worn surfaces of the knee are removed and resurfaced using a metal joint. A highly specialized liner made of polyethylene is inserted between the two metallic surfaces to replace the worn meniscus. There are broadly two types of knee replacements- unicompartmental (partial) and total knee replacement.

Knee joint is divided into three compartments If the arthritis is limited to only one compartment (medial compartment is the one most commonly affected) then a unicompartmental replacement is possible. The advantage is that this is done through a small incision removing only a small amount of bone making potential revision operations in future easier. Hence in younger patients I prefer a unicompartmental replacement to preserve more bone stock.

Prior to the operation patient the will need to undergo a clinical examination including a dental check and urine culture to look for a potential infection. If an infection is identified this will need to be treated prior to surgery. If the patient has had medical problems such as previous heart attacks, angioplasty or bypass surgery arrange a cardiology consultation to ensure they are fit from a cardiology point of view for surgery. Similarly consultation with a neurologist or a nephrologist is required in patients with neurological/ renal problems respectively.

This surgery is generally done under spinal anesthetic along with a light sedation. This is very safe with reduced risk of vomiting and chest infections as compared to a full general anesthetic. Should the patients wish for a general anesthetic it is possible. Around a third of patients require a blood transfusion. In patients who do not wish to have blood products (e.g. Jehovah’s Witnesses) it is possible to avoid transfusion through a variety of drugs.
The first 24 hours after surgery, the patients are in an intensive care unit. The day following surgery the patients are made to walk, putting full weight through the operated leg. Iinitially this will be on crutches or on a walker. Usually by day three or four the patient can get out of aided, can dress themselves, walk up and down the corridor. At this stage they are normally ready for home. Most patients will have some amount of pain for up to 6 weeks after discharge. Common post operative include constipation, depression and sleeplessness.

They may also be low in self esteem as they have to depend on others for their personal needs for the first 1-2 weeks. The patients will need extra care and support from their family members through this period. These problems will settle by around six weeks. Following discharge, I recommend a daily walk with walking aids such as crutches or sticks. The patients can stop using this in the first few weeks once the patient is feeling confident to walk independently. I encourage elderly patients to start going to temple/church/mosque once the sutures are off. I have found this particularly helpful in elderly patients as this improves their self-esteem and morale.