Unicompartmental (partial) knee replacement

If arthritis affects only one side of your knee – usually the inner side – it may be possible to have a half-knee replacement (sometimes called ‘unicompartmental’ or partial replacement).

This gives just as good pain relief as a total knee replacement but with less bruising and scarring. The range of flexion is often as good as before the operation. It’s also a less extensive operation and should therefore mean a quicker recovery.

Partial knee replacements can often be carried out through a smaller incision than a total knee replacement, using techniques called reduced invasive or minimally invasive surgery.

Partial knee replacement isn’t suitable for everyone because you need to have strong, healthy ligaments within your knee. Sometimes this won’t be known until the time of surgery. If a partial knee replacement isn’t successful a second operation may be needed to convert it to a total knee replacement.

You’re more likely to need a repeat operation for partial knee replacements than for total knee replacements. It’s usually easier to convert a partial knee replacement to a total knee replacement than to convert a failed total knee replacement. Partial knee replacement is therefore preferred for younger patients, who are more likely to need further surgery at some point. But it may also be used in some older patients because it’s a less stressful operation.