The surface in the bones in a normal knee joint is covered with a layer of articular cartilage. Arthritis is a condition where this articular cartilage surface is damaged and this can often result in pain, stiffness and loss of function. Symptoms can include difficulty with walking, dressing and sleeping.

Replacement surgery involves replacing this worn joint surface with a metal surface. The worn surface of the knee is re-lined with a metal surface.

The knee joint is divided into three portions or compartments. Medial, lateral and patello-femoral.

Knee replacement surgery can involve replacement of individual compartments of the knee or all of the knee joint compartments.
 

Potential complications with knee surgery

There are risks with all surgical procedures. The risk of the anaesthetic itself with modern anaesthetic techniques is very low.

There are general risks of surgery, which include blood clots, infection of the wound, post-operative bleeding, difficulty passing urine, chest infections and heart attacks or strokes.

Deep infection of the replacement is fortunately uncommon, occurring in 1-2 per thousand cases. Risk of infection if reduced by performing the operation in a clean, laminar flow theatre environment. The surgical team wear sterile clothing and antibiotics are given around the time of the operation.

Deep vein thrombosis can occur after surgery and the risk of this is reduced by using stockings in the post-operative period and giving preventative thinning blood agents around the time of the surgery and for several weeks post-operatively.

Patients can experience numbness on one side of the scar and this will return.

A foot drop can occur following damage to one of the nerves on the side of the knee, this generally resolves over a period of days to weeks. Long term permanent foot drop is rare.

Early failure of the knee replacement is very uncommon, but knee replacements have a limited life span and over time will wear and loosen.