On this page
- What the disease actually does
- Standard treatment, which comes first
- Why the knee dominates the evidence
- What that means for other joints
- Symptom change versus structural change
- Who tends to be considered
- Risks and trade-offs
- What to ask before proceeding
- Reading further
- Frequently asked questions
- Requesting a medical evaluation
Osteoarthritis is where regenerative medicine has its best case and its most overstated one at the same time. Osteoarthritis and stem cell therapy has genuine randomised evidence in the knee, considerably less in every other joint, and a marketing vocabulary borrowed from a model of how the cells work that the research has largely moved past.
What the disease actually does
Articular cartilage is the smooth surface capping the ends of bones inside a joint. It has no blood supply and no nerves, which is why it repairs poorly and why cartilage damage itself does not hurt.
In osteoarthritis that surface thins and fissures. The bone underneath remodels and thickens, small outgrowths form at the joint margins, and the synovial lining becomes inflamed in episodes.
The pain comes from the bone, the lining and the surrounding soft tissue rather than from the cartilage. That is worth knowing, because it explains why symptoms and X-ray appearance correspond so poorly, and why a treatment aimed purely at cartilage might not change how a joint feels.
It is also why “wear and tear” is a poor description. There is an active inflammatory and remodelling process, not simply erosion.
Standard treatment, which comes first
Exercise therapy has evidence as good as anything discussed on this site. Strengthening the muscles around a joint reduces pain and improves function across multiple trials, and it is consistently the option people skip.
Weight reduction matters where relevant, because load through the knee is a multiple of body weight. Simple analgesia and topical anti-inflammatories help many people at low cost and low risk.
Corticosteroid injection provides short-term relief. Hyaluronic acid injection has a more contested literature. Both are cheaper and more available than cell therapy.
Joint replacement is among the more reliably effective operations in medicine for advanced disease. Regenerative treatment is usually discussed by people past the first group and not yet ready for the last.
Why the knee dominates the evidence
Almost all the randomised work has been done in knees, for practical reasons rather than biological ones. The joint is large, superficial, easy to inject accurately without imaging guidance, and easy to assess with validated scores.
A 2025 systematic review and meta-analysis pooled randomised trials in the knee — Efficacy and safety of mesenchymal stem cells in knee osteoarthritis — and a 2024 network meta-analysis compared cell types within it — which cell and type are more beneficial.
Individual randomised trials include a phase III study of autologous adipose-derived cells — Clinical Efficacy and Safety of the Intra-articular Injection of Autologous Adipose-Derived Mesenchymal Stem Cells — and a cord-derived dosing comparison — Repeated MSC Dosing Is Superior to a Single MSC Dose.
See the knee page for that evidence in detail.
What that means for other joints
The hip is deeper, harder to inject accurately, and much less studied. The shoulder is a different mechanical problem again, where rotator cuff pathology often accompanies joint surface change. The hand and thumb base are barely studied at all.
Biological similarity is a reason to hypothesise that results transfer. It is not evidence that they do, and joints differ in load, geometry, and how much of the pain comes from the joint surface at all.
A clinic quoting knee trial results while proposing to inject your hip is extrapolating. That may still be reasonable — but it should be described as extrapolation.
See hip osteoarthritis for what does and does not exist there.
Symptom change versus structural change
These are measured differently and they are routinely conflated in sales material.
Symptom improvement is a change in a pain or function questionnaire. Structural change is a measurable difference in cartilage thickness or joint space on imaging. Most trials report the first.
A review asked directly whether biologic injections modify the disease rather than the symptoms — Biologic injections for osteoarthritis and articular cartilage damage: can we modify disease? — and a 2025 prospective randomised study looked at cartilage specifically in early disease — Cartilage Regeneration Potential in Early Osteoarthritis of the Knee.
See cartilage regeneration research for how each endpoint is assessed.
Who tends to be considered
Trial populations were generally mild to moderate rather than end-stage, with cartilage remaining, reasonable alignment, and conservative treatment already tried.
End-stage bone-on-bone disease was commonly excluded. That is exactly the group most motivated to seek treatment abroad, which creates a persistent mismatch between who wants this and who was studied.
Significant malalignment changes the mechanics of a joint, and injecting cells into a knee that is loading unevenly addresses the wrong problem.
Inflammatory arthritis is a different disease and is assessed differently — see rheumatoid arthritis.
Risks and trade-offs
Joint injection carries a small risk of septic arthritis, which is uncommon and serious. Transient pain and swelling for several days afterwards is common and expected.
An autologous harvest is a second procedure with its own donor-site risks, whether from abdominal fat or pelvic marrow.
The financial trade-off is real: this is expensive, the alternatives are not, and the evidence for the alternatives is in several cases just as good.
See adverse events for the fuller picture.
What to ask before proceeding
The answers distinguish a clinic assessing you from one selling to you.
- Which joint, and what evidence exists for that specific joint?
- What grade is my disease, and was that grade represented in the trials?
- Cell source, dose and number of treatments?
- What happens if imaging shows I am too advanced to benefit?
- What would you recommend if I could not afford this?
That last question is more informative than it sounds — see the main treatment page.
Reading further
Cartilage damage covers focal defects, which are a different problem from generalised osteoarthritis.
MSC therapy covers the cells themselves, and PRP covers a cheaper injection often confused with them.
The knee studies page sets out each trial with its design and limitations.
The joint-specific pages sit under this one: knee, hip and ankle osteoarthritis, which has the smallest literature of the three.
Frequently asked questions
Which joints have actual evidence?
The knee, by a wide margin. Hip, shoulder and hand are much less studied, and knee results are often applied to them without justification.
Is this wear and tear?
Not really. There is an active inflammatory and remodelling process, which is part of why anti-inflammatory approaches have a rationale at all.
Does it work for bone-on-bone arthritis?
End-stage disease was generally excluded from trials, so evidence is weakest exactly where people most want it to be strong.
Will it rebuild my cartilage?
Most trials measured symptoms rather than cartilage. Structural change is assessed less often and shown less consistently.
How does it compare with a steroid injection?
Head-to-head data is limited. Steroid works quickly and briefly; the case for cells rests on a longer effect that trials test imperfectly.
What if my knee is badly malaligned?
Then load is the dominant problem, and injecting cells into an unevenly loaded joint addresses something else. That needs an orthopaedic opinion first.
Requesting a medical evaluation
Nothing on this page establishes whether any treatment is appropriate for you. That needs your history, your imaging and your current medications read by a clinician. If you would like that review, send your records and we will tell you honestly whether there is anything worth discussing — including when the answer is no.
This page is general information, not medical advice, and does not create a doctor–patient relationship. Regenerative treatments discussed here are in most cases investigational. Discuss any treatment with a clinician who knows your history.