In the know about knee replacements

When it gets to the point that a knee replacement becomes the only option, it might feel good to know that relief is more than likely it’s on its way - but also nerve-wracking in regards to going through the operation.

Here to shine a light on when the procedure is required, revision knee replacements and how successful knee replacements are, among other interesting points, is leading orthopaedic hip and knee surgeon in Salisbury, Mr Stephen Veitch.

When is a knee replacement required?

A knee replacement should be considered for patients with significant pain and limited function due to knee arthritis, when non-surgical options such as pain medication are no longer controlling their symptoms.

How many knee replacements might a person need in their lifetime?

For the vast majority of patients, a single knee replacement will be all they need. The average survivorship of a knee replacement is 25 years. In a very small number of patients a further knee replacement (revision) may be necessary.

The reasons for this can be:

• Due to implant loosening from wearing of the implant;
• Progressive arthritis if a partial knee replacement is used;
• Infection;
• Fracture causing loosening and instability when the replaced knee regularly gives way.

How is it performed?

The operation is performed under a spinal and/or general anaesthetic. The skin is coated in antiseptic and the leg covered with sterile drapes, the incision is made at the front of the knee, the knee cap (patella) is moved to one side and the knee joint is exposed. Alignment jigs are used to ensure accurate sizing and positioning of the implants. Cuts are made removing any remaining cartilage and a small amount of bone in such a way to allow the implants to be seated in position.

Initially, trial implants are used to confirm that the knee fully straightens and bends smoothly, the patella tracks smoothly and the knee is stable. The definitive implants (cobalt chrome metal alloy) are then cemented into the bone using bone cement and the polyethylene liner inserted. If the patella cartilage is worn then the cartilage is removed and resurfaced with a cemented polyethylene implant at the same time.

The knee is washed with sterile saline, local anaesthetic injections performed around the deep and superficial tissues. Then the knee is closed in layers with sutures and a dressing is applied.

How successful are knee replacements?

The majority of patients are very pleased with the pain relief and their quality of life following a knee replacement. The knee can be uncomfortable and swollen for the first three months after surgery. In a small number of patients, the knee takes a longer time than usual for pain, swelling and stiffness to improve.

What are the most commonly reported side effects of knee replacements?

Stiffness and swelling; particularly in the first three months. Occasionally the knee can remain uncomfortable during the first year. A small area of skin on the outer aspect of the knee next to the incision can lose its sensation. However, this skin loss is rarely troublesome for patients.

If you would like an assessment for a knee replacement or are experiencing pain that requires treatment, make an appointment with Mr Veitch via his Top Doctors profile.