Chronic knee pain explained.

What causes chronic knee pain?

Knee osteoarthritis

The most common cause over 45. Deep aching, stiffness after rest that eases within about 30 minutes, and pain that increases with prolonged load. Osteoarthritis is now understood as a whole-joint condition involving cartilage, bone, synovium, and surrounding muscle — not a simple mechanical wearing-out.

Patellofemoral pain

Pain around or behind the kneecap, classically worse on stairs, squatting, and after long periods sitting. Common in younger and active people. It responds well to hip and quadriceps strengthening, which is often more effective than anything aimed at the kneecap itself.

Degenerative meniscal changes

Meniscal tears found on MRI in middle age are usually degenerative rather than traumatic, and they are extremely common in knees that do not hurt. A tear on a scan in someone over 50 is often an incidental finding, not the diagnosis.

Tendinopathy

Patellar or quadriceps tendon pain — well localised, load-related, and responsive to progressive loading rather than rest.

Referred pain

Hip pathology refers to the knee often enough that any knee assessment should include the hip. In children and adolescents this is especially important, because hip conditions can present as knee pain alone.

What does 'bone on bone' actually mean?

It means the X-ray shows narrowed joint space. It is a radiological description, and it is a phrase that does measurable harm when it is heard as a prognosis.

Radiographic severity and pain severity diverge in both directions. Plenty of people with severe changes on film walk, work, and exercise with little pain; plenty of people with mild changes have significant pain. The correlation is real but weak, which means the picture cannot tell you what your knee is capable of.

Practically, this means a diagnosis of osteoarthritis is not a reason to stop loading the knee. It is a reason to load it deliberately, at the right dose, with enough strength around it to share the work.

How is chronic knee pain treated?

1. Exercise therapy — the strongest recommendation in every osteoarthritis guideline. Strengthening plus aerobic activity reduces pain and improves function.
2. Load management. Adjust volume and intensity rather than stopping. Pain during exercise that settles within 24 hours is generally acceptable.
3. Weight management where relevant, which reduces both mechanical and inflammatory load.
4. Topical and oral NSAIDs for symptom control, with topical preferred first for knee osteoarthritis.
5. Injections, selectively. Corticosteroid injections give short-term relief; benefit is measured in weeks, not months.
6. Joint replacement for end-stage arthritis with substantial functional loss that has not responded to a real course of conservative care. It is an excellent operation for the right person at the right time.

What the evidence does not support

Arthroscopic partial meniscectomy for degenerative tears without mechanical locking has failed to outperform sham surgery or exercise therapy in multiple randomised trials. Guidelines now recommend against it for this indication.

How Karuna can help

Where knee pain has persisted for months or years, the limiting factor is often not the joint but everything built around it: the movements you have stopped attempting, the flare-ups you now anticipate, and a nervous system that has become quicker to protect.

Karuna's 12-week program uses virtual reality embodiment training and graded exposure to rebuild confidence in loading and bending the knee, supported by weekly one-on-one coaching and physician oversight. It runs entirely from home. See how it works.