Gonarthrosis affects up to 30% of people over 60 years old. Early diagnosis and the right treatment choice at each stage — the key to preserving your joint.

Kellgren-Lawrence Classification

The international Kellgren-Lawrence (KL) classification assesses osteoarthritis based on X-ray findings. This is the standard used by orthopedic surgeons worldwide to determine treatment strategy.

Stage I (KL 1): early changes

Cartilage loses elasticity; the X-ray shows doubtful joint space narrowing. There is discomfort after activity and brief morning stiffness. What helps: thigh strengthening, weight loss, adjusting activity. Exercise therapy has the greatest effect at this stage.

Stage II (KL 2): mild osteoarthritis

Definite osteophytes appear and the joint space may narrow slightly. Pain on walking, crepitus, sometimes swelling. What helps: the same exercise and weight control, a short course of NSAIDs during flare-ups. Hyaluronic acid or PRP injections reduce pain for several months in some patients; they cannot restore cartilage.

Stage III (KL 3): moderate osteoarthritis

The joint space is clearly narrowed, osteophytes are large and axis deformity may develop. Pain with light activity, sometimes at rest. What helps: an exercise programme, braces and insoles, injections during flare-ups. Cell-based methods reduce pain in some patients, but there is not enough evidence that they delay joint replacement for long. With severe pain and limited walking, surgery is discussed — knee replacement or, in active patients with one compartment affected, an osteotomy.

Stage IV (KL 4): severe osteoarthritis

The joint space has almost disappeared, deformity is marked and movement is limited. The most reliable way to reduce pain and restore walking is knee replacement. Injections give only temporary relief and are used when surgery is not possible or the patient is not ready for it.

Does osteoarthritis always progress?

No. Osteoarthritis develops differently in each person: in many, the stage and symptoms remain stable for years, and pain does not always match the X-ray. Weight loss, strong muscles and sensible activity help slow progression. More on treatment on the knee osteoarthritis page.

Who it is not suitable for and possible risks

Contraindications

  • Active infection — at the injection site or systemic, with fever.
  • Active cancer or ongoing chemotherapy.
  • Blood clotting disorders or a low platelet count. Anticoagulants are discussed with the physician.
  • Pregnancy and breastfeeding — the procedure is usually postponed.
  • A corticosteroid injection into the same area in recent weeks.
  • Severe stage IV osteoarthritis with axial deformity and joint destruction — joint replacement is usually discussed instead.

Possible risks

  • Pain and swelling at the injection site for 1–3 days.
  • Bruising where blood or fat tissue is taken.
  • Rarely, infection. The procedure is therefore performed under sterile conditions with ultrasound or X-ray guidance.
  • The effect may be absent or smaller than expected.

If any of these apply to you, mention it in your request. The coordinator will check with the clinic physician whether treatment is possible. Contact a coordinator.

Scientific evidence

Studies of regenerative methods show mixed results. Clinic physicians rely on research including the following:

  1. KELLGREN JH et al. Radiological assessment of osteo-arthrosis. Ann Rheum Dis, 1957.
  2. Bannuru RR et al. OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthritis Cartilage, 2019.

Next steps: Treatment methods · Treatment cost · How treatment in Germany is organised

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Describe your case and attach your MRI report. We will identify clinics that use the relevant methods and forward your request to them. No obligation; we reply within 24 hours.

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Frequently asked questions

How is the stage of knee osteoarthritis determined?

The stage is set on a standing X-ray using the Kellgren–Lawrence scale (0–IV): joint-space narrowing, osteophytes and deformity are assessed. MRI also shows cartilage, menisci and bone oedema.

Can knee osteoarthritis be stopped?

It cannot be stopped completely, but weight loss, strengthening the thigh muscles and graded activity slow it down and reduce pain. This is the best-proven treatment at every stage.

Which stage of osteoarthritis needs a knee replacement?

Most often stage IV with severe pain and deformity, sometimes stage III if pain cannot be controlled. The decision is based on pain, function and the X-ray together, not on the image alone.

How does RegenPAS help organise treatment?

RegenPAS is a patient service centre in Munich, not a clinic. We review your images and symptoms and send a request to several partner clinics at once. Clinics that can accept you send their own conditions and price; prices differ between clinics, and you choose the option that suits you. The coordinator replies within 24 hours, and a clinic physician’s preliminary opinion follows in 1–3 business days. We then arrange the appointment, visa invitation, interpreter, transfers and accommodation. Treatment decisions are made by the clinic physician. Contact a coordinator.

How much does treatment cost and how long do I need to stay in Munich?

The cost depends on the method, the diagnostics needed and the clinic itself: prices differ between clinics. We request offers from several clinics and send you their conditions and quotes so you can compare. Price guidance is on the treatment cost page. For an outpatient procedure, 2–3 days in Munich are usually enough: examination, procedure and follow-up visit.