MECHANISTIC AND CLINICAL STUDY OF INTRA-ATICULAR ARTHROSAMID® FOR KNEE OSTEOARTHRITIS

Clinical Delivery and Analysis: The ACTIVE consortium with Martyn Snow, Lee Midleton, Samir Mehta, Andrew Roberts and Jan Herman Kuiper

Funded by the Orthopaedic Institute and the Medical Research Council.

ACTIVE is a large international multicentre randomised controlled trial that compared two options of treating knee cartilage defects: autologous chondrocyte implantation (ACI) versus cell-free types of surgery such as microfracture or debridement. ACTIVE was conceived and championed by the late Prof. James Richardson, who persuaded 27 hospitals in the UK and two in Norway to take part, forming the ACTIVE consortium. Between December 2004 and January 2011, teams at these hospitals recruited, randomised and treated 390 patients. Half of them were treated with ACI, and the other half with another type of cartilage surgery. Every year the patients filled in questionnaires asking about their knee and general health, and 1, 3 and 5 years after the operation they returned to the clinic.

In 2023, we published how the two treatment options compared five years after the surgery. Now we have also completed the analysis of how they compare ten years after surgery. On average, patients who had ACI reported a better outcome than patients who had other types of surgery, but this is partly because of further surgery. Around 25% of patients in both groups needed revision surgery because the original treatment had failed, which was of slightly more benefit to patients who had ACI. In other words, the results are not entirely clear. However, the trial has given one very clear result, which concerns cartilage treatments that patients had before entering the trial. According to the ACTIVE results, the results of ACI are the same regardless of earlier treatment. This contradicts current government advice that patients who had earlier cartilage repair surgery should not have ACI.