Regenerative and orthobiologic treatments

Regenerative, or orthobiologic, treatments use material prepared from your own body to support repair in a damaged joint or tendon. The most common is platelet-rich plasma (PRP): a small amount of your blood is drawn and spun in a centrifuge, and the platelet-rich layer is injected into the problem area. Cell-based preparations are made from a small sample of your own fat tissue or bone marrow, taken under local anaesthetic.

The idea is that growth factors in the concentrate calm inflammation and encourage healing. That is the theory; whether it helps in practice depends on the condition, and the evidence is set out below.

For stem cell injections, a 2025 Cochrane review of 25 randomised trials found that, compared with a placebo injection, they may slightly reduce pain and improve function for up to six months — on average by about 1.2 points on a 0–10 pain scale. The certainty of this evidence is low, none of the trials measured whether the joint changed on X-ray, and long-term safety is uncertain 1.

For PRP, in a placebo-controlled trial 288 people with knee osteoarthritis received three weekly injections of either PRP or saline. At 12 months PRP was no better than saline for pain or for cartilage volume 2. The American College of Rheumatology and Arthritis Foundation guideline recommends against both PRP and stem cell injections in knee and hip osteoarthritis, pointing to how much the preparations vary and how little they are standardised 3.

For tendon and other soft tissue injuries — including tennis elbow, rotator cuff, patellar and Achilles tendon problems — a Cochrane review of 19 small trials found insufficient evidence to support platelet-rich therapy and rated the evidence as very low quality. It also noted that preparation methods varied and were not standardised, which makes results hard to compare 4.

This is why these injections are not a first step. Exercise is strongly recommended for knee and hip osteoarthritis 3, and an injection is considered only after exercise-based rehabilitation has been tried properly.

Adults with early or moderate osteoarthritis of the knee, hip, shoulder or ankle, a focal cartilage lesion, a chronic tendon problem, or a ligament or meniscus injury — when medication, exercise and physiotherapy have not been enough. Suitability is decided by a physician after examining you and reviewing your imaging.

It is not offered with an active infection or active cancer, a blood or clotting disorder, during pregnancy or breastfeeding, with uncontrolled diabetes, while taking immunosuppressive medication, shortly after a steroid injection into the same area, or in end-stage osteoarthritis. If you take a blood thinner, tell us before your appointment.

The procedure is completed in a single day. For PRP, blood is drawn from your arm; for a cell-based preparation, a small sample of fat or bone marrow is taken under local anaesthetic. The sample is processed under sterile conditions and injected the same day, usually under ultrasound guidance so the needle reaches the intended spot. You then stay under observation for a short time.

Depending on the condition, one session may be enough or several are planned a few weeks apart. Rehabilitation begins in the following days, and the result depends on it: the injection may ease pain enough for you to load the joint or tendon properly, and the exercise programme does the rest.

Pain, swelling or bruising at the injection site for a few days is common. Your physician will tell you which painkillers to use and which to avoid in the first days. Contact us straight away if you develop a fever, spreading redness, discharge from the injection site or pain that keeps getting worse.

Any effect builds gradually over weeks rather than days. Some people notice little or no change, and that is worth knowing before you decide.

Exosomes are tiny particles released by cells. They are being studied in conditions such as cerebral palsy, spinal cord injury, stroke, traumatic brain injury, multiple sclerosis, Parkinson's disease and ALS, and are given by intravenous, intramuscular or intrathecal injection.

This is experimental, and it has not been shown to restore lost function in any of these conditions. The US Food and Drug Administration states that there are no approved exosome products and has warned of serious adverse events in patients who received unapproved ones 5. The International Society for Stem Cell Research cautions against selling unproven cell-based interventions to patients and notes that patient registries are no substitute for controlled trials 6.

If you ask about it, a physician will discuss it with you on those terms. It never replaces rehabilitation: after a stroke, for example, recovery depends on a sustained programme delivered by a coordinated team 7.