Surgeon says yes to a new knee. Everyone I know who's had one has a numb patch by the scar. Does the feeling ever come back?

Saw the surgeon last week, the appointment some of you talked me into. Right knee, total, on the list. Strange mix of relieved and terrified which I gather is the house mood in this section.

Since then I've done the thing where you mention it at the walking group tea stop and suddenly discover everyone's had one. Three people with new knees, all lovely about it, all very glad they did it. And all three, without me asking, told me about a numb patch on the outside of the scar. One said it's been five years and she still can't feel her knee when she kneels in the garden. Another said hers has "mostly" come back. The third just shrugged and said you get used to it.

Nobody mentioned this at the appointment. It's not a dealbreaker, I don't think, but I'd like to know what I'm signing up for. Is it everyone? Does it go? And is it a sign they've damaged something, because "numb" sounds like nerves to me and nerves sound serious.

Sue, I'm one of the club. Mine is roughly the size of a credit card, outer side of the scar, a bit below the kneecap. Felt huge and very weird for the first few months, like the skin was somebody else's. It's shrunk from the edges since, slowly, and a few years on it's a strip about two fingers wide that I only notice if I'm rubbing cream in or kneeling.

It has never once affected how the knee works. Walking, stairs, the aqua classes, all fine. It's a skin thing.

Question for whoever knows. If they know it's going to happen to almost everyone, why can't they avoid the nerve? Is it just that the cut has to go where it goes?

walkinggroupsue said:

is it a sign they've damaged something

Sue, the direct answer: a numb patch on the outer side of the scar is expected after a knee replacement, it is not a sign that something has gone wrong, and it does not affect how the knee works. The American Academy of Orthopaedic Surgeons says most people feel some numbness in the skin around the incision. Versus Arthritis describes it at the outer edge of the scar and says it usually improves over about two years, but that it is unlikely to return completely to normal. Your three friends are a fair sample: one mostly back, one still noticeable when kneeling, one who has stopped thinking about it.

Pete, to your question: it is the cut. Several small sensory nerves run across the front of the knee just under the skin, travelling from the inner side towards the outer side, the best known being a branch of the saphenous nerve. A front of knee incision crosses their path, so the skin beyond it, on the outer side, loses some of its supply. Surgeons vary the incision a little but you cannot open a knee from the front without dividing some of those fine nerves. They carry feeling from the skin only and control no muscle, which is why Maureen's knee works normally around her patch.

What is not the normal patch, and would need the surgical team promptly: numbness spreading well beyond the scar into the shin or foot, weakness lifting the foot, or numbness with a knee that is hot, red, increasingly swollen or increasingly painful. Practical points for the numb skin itself are care with hot water bottles and heat pads, since you may not feel a burn starting. The new guide on numbness after a knee replacement covers this in more detail, and kneeling after a knee replacement is worth reading for the garden. Asking your own surgeon about it at the pre operative appointment is entirely reasonable; it is a good question, not a fussy one.

That's exactly what I needed. Expected, skin only, and here are the three things that aren't. Not a dealbreaker then, just something to know about. I've told the tea stop lot they're officially a representative sample and they're unbearably pleased with themselves.

Hot water bottle point noted. I live on one in winter.

Late but useful to know for the future. My dad had his done years ago and used to put his hand on the patch and say "dead bit" to make us laugh. Never bothered him otherwise.