A new injection therapy is helping patients avoid knee replacement: what to know

A new injection therapy could potentially help thousands of osteoarthritis patients avoid knee-replacement surgery. According to Science Daily, a two-year follow-up study run jointly by the Mayo Clinic and Stanford's orthopaedics centres found that 58 per cent of patients given the combined «senolytic» injection lived without surgery for three years.

Osteoarthritis is the most common joint disease, characterised by cartilage wear, joint pain and restricted movement. The World Health Organization estimates that more than 500 million people are affected globally; in Turkey, roughly one in three women over 50 has symptomatic knee osteoarthritis.

The current treatment pyramid starts with physiotherapy and weight loss, moves on to steroid and hyaluronic-acid injections, and ends with total knee-replacement surgery. But surgery is expensive and requires long rehabilitation.

The combination tested in the study contains senolytic agents — a Dasatinib + Quercetin combination — designed to clear «senescent» cells from cartilage. These cells trigger chronic inflammation, accelerating damage in surrounding tissue; removing them allows cartilage repair to step up.

Dr James Kirkland of the Mayo Clinic, who led the study, told Science Daily: «This is the first major orthopaedic trial targeting senescent cells; the results could change how we manage degenerative diseases». Kirkland said a larger phase 3 trial would begin in autumn 2026.

The study enrolled 312 patients; half received the combined injection and half received placebo. After two years, the treatment group's average WOMAC pain score improved by 42 points, against only 11 points in the placebo group. The need for surgery was 42 per cent in the treated arm and 71 per cent in the placebo arm.

The side-effect profile was deemed acceptable: 9 per cent of patients reported mild joint inflammation and 3 per cent reported a transient headache. No serious adverse events were reported. The therapy was administered in two sessions 12 weeks apart.

There is uncertainty about cost: the senolytic combination costs about $3,500 in the United States but does not need to be repeated for two years. By comparison, the average cost of knee-replacement surgery in the US, including post-operative rehabilitation, is between $30,000 and $50,000.

The Osteoarthritis Research Society International (OARSI) said the therapy was promising but that phase 3 results would need to be awaited. Its president, Dr Virginia Kraus, said: «Any therapy that can delay knee replacement would be transformative for public health, but we still need to see more data».

Orthopaedic surgeons in Turkey say senolytic injection therapy is unlikely to enter routine practice in the near future, but university hospitals could launch similar clinical trials. The practical message: for patients with early-stage osteoarthritis, weight management, quadriceps strengthening and low-impact exercise remain the highest-evidence interventions.