Key points
- Pain at the front, worse on stairs and after sitting, is usually the kneecab tracking under load rather than damage.
- Osteoarthritis responds to strength training. It is the most effective non-surgical treatment there is for it.
- Meniscal tears are common findings on scans in people with no knee pain.
- A knee that gives way, locks, or swelled immediately after an injury needs assessing promptly.
- The hip is involved in most knee pain, and is the most commonly skipped part of treatment.
Where it hurts narrows it down
- Front, around or under the kneecap, worse on stairs and after sitting: patellofemoral pain
- Inside of the joint, with stiffness in the morning that eases within half an hour: osteoarthritis
- Inside, after a twisting injury, with swelling over hours and possibly catching: meniscus
- Outside, in runners and cyclists, coming on predictably after a certain distance: IT band related
- Just below the kneecap in jumping sports: patellar tendon
Pain at the front is not wear and tear
Patellofemoral pain is the most common knee complaint in people under forty, and it is a load problem rather than a damage problem. The kneecap runs in a groove; when the muscles controlling it are not up to the demand, or the hip lets the knee fall inward, the load concentrates and the area becomes sensitive.
That is why the treatment is quadriceps and hip strengthening, and why it works. It is also why rest alone reliably fails: after two weeks off, the tissue tolerates less than before.
Osteoarthritis and the wear and tear story
People are commonly told their knee is worn out, as though it were a bearing with a fixed number of rotations left. That framing is wrong and it does real harm, because it convinces people to stop loading the joint, which is the one thing that reliably helps.
Strength training is the most effective non-surgical treatment for knee osteoarthritis. Stronger legs, more capacity, less pain, better function. Cartilage does not regrow, but pain and function are not determined by cartilage thickness, which is why people with severe imaging findings can be comfortable and people with mild findings can be miserable.
Joint replacement is an excellent operation for the right person at the right time. It is not the only option available the moment an X-ray shows degeneration.
What needs prompt assessment
- Swelling within an hour of an injury, which suggests bleeding in the joint
- The knee giving way under you
- True locking, where the knee will not straighten and you cannot force it
- Inability to bear weight after an injury
- A hot, swollen, painful knee with fever, which needs same-day medical review