Knee Replacement Scar Tenderness: Why It Happens and How to Soothe It

By Mr. Khaldoun Bitar Consultant Hip and Knee Surgeon in Wolverhampton

If you’ve had a knee replacement surgery , you may wonder: “Why does my scar feel so sensitive or even numb?” You’re not alone — and understanding why this happens can help you manage it with confidence.

Why does a knee scar feel tender after knee replacement?

Your knee is more than just a hinge — it’s an intricate joint that supports your body weight and keeps you moving. To do all this, the knee has a rich network of small nerves.

When we replace your knee, we make an incision through skin and tissue. Some tiny nerves are cut during this process — this is normal and unavoidable. As these nerves heal, the scar and nearby skin can feel:

• Tender to touch

• Tingly or “electric”

• Numb in patches, especially on the outer (lateral) side

Many patients notice a numb area on the outside of the scar that may shrink over time but can sometimes remain permanently.This usually is well tolerated and is not a cause for concern.

Why are knee scars more sensitive than hip scars?

There are a few reasons why knee scars can feel more sensitive than scars over deeper joints, like the hip:

Closer to the surface: The knee joint sits just under the skin with less padding than the hip, which lies deep under layers of muscle and fat.

Always moving: Your knee bends through a large arc every day. Sitting, standing, stairs, and kneeling constantly stretch the scar, which can keep it tender for longer.

Your brain “listens” carefully: The brain’s pain map — the sensory homunculus — gives special attention to joints that help us stand and walk. This means any unusual signals from the knee are picked up quickly. Sometimes this makes normal healing sensations feel stronger than they really are.

How long does scar tenderness last after knee replacement surgery?

Tenderness and tingling often fade over weeks to a few months as the nerves heal and settle down.

Some numbness, especially on the outside of the scar, can stay long term ( few months). This varies amongst patients. This is harmless and won’t affect how well your knee works.

If your scar area becomes unusually painful, hot, swollen, or you are worried about how it’s healing, always speak to your surgeon.

Tips to reduce scar tenderness after knee replacement

Scar massage

Once your wound has fully healed, gentle daily massage can soften the scar, reduce tightness and calm sensitivity.

Desensitisation

Lightly tapping or stroking the scar area with different textures, like a soft cloth, can help retrain the healing nerves and calm the brain’s response.

Moisturise

Keeping the skin supple with a gentle plain cream or oil helps.

Protect numb areas

If part of your knee stays numb, take extra care when kneeling or using heat or cold packs, as you may not feel a burn or bump the same way.

Final Thoughts

Some scar tenderness or numbness after knee replacement is normal — and for most people, it fades into the background as your new knee lets you get back to the things you love.

If you ever have concerns, don’t hesitate to ask — no question is too small. Your comfort, confidence and recovery are all part of the journey we take together.

For general scar care advice, see the NHS wound healing guide.

Written and medically reviewed by Mr Khaldoun Bitar — Consultant Hip & Knee Surgeon,UK. References available on request.