The KORAL study aimed to assess the effectiveness and cost-effectiveness of arthroscopic lavage for the treatment of osteoarthritis of the knee.  It was proposed to carry out a large multi-centre placebo controlled trial across the UK, but given potential concerns about including a placebo surgery arm the study was designed with an initial exploration of acceptability and a formal pilot.  The initial exploration of acceptability comprised: focus groups with surgeons and anaesthetists; focus groups and interviews with potential participants; interviews with Chairs of UK Multicentre Research Ethics Committees; and surveys of surgeons and anaesthetists.  The pilot study was designed as a two-centre, three-arm trial of arthroscopic lavage (with or without debridement at the clinical discretion of the surgeon); placebo surgery; and non-operative (ie medical) management with specialist re-assessment. 

The acceptability phase showed there was broad acceptance across all stakeholder groups of the need to find out more about the effectiveness of arthroscopic lavage.  Despite this there was variation in opinion within all the groups about how researchers should approach this and whether or not it would be acceptable to investigate using placebo surgery.  The pilot study showed that, in principle, a placebo-controlled trial could be conducted.  It showed that patients were willing to participate in a trial which would involve a placebo-surgical arm and that it was possible to undertake placebo surgery successfully and to blind patients to their allocation.  The experience of the pilot, however, showed that, despite full MREC approval, the study required major discussion and negotiation before local clinical approvals could be obtained.  The fact that ethics approval had been granted did not mean that clinicians would automatically accept that the process was ethical. 

The study showed that, in principle, a placebo-controlled trial of arthroscopic lavage could be conducted in the UK, albeit with difficulty.  Against this background, and external data showing falling use of arthroscopic lavage, the decision was taken that the time and effort required to deliver a full-scale trial was not justified for this procedure at this time. 





Campbell MK, Entwistle VA, Cuthbertson BH, Skea ZC, Sutherland AG, McDonald AM, Norrie JD, Carlson RV, Bridgman S and the KORAL study group. Developing a placebo controlled trial in surgery: Issues of design, acceptability and feasibility. Trials 2011; 12:50

Campbell MK, Skea ZC, Sutherland AG, Cuthbertson BH, Entwistle VA, McDonald AM, Norrie JD, Carlson R, Bridgman S for the KORAL study group.  The effectiveness and cost-effectiveness of arthroscopic lavage in the treatment of osteoarthritis of the knee: a mixed methods study of the feasibility of conducting a surgical placebo-controlled trial (the KORAL study).  Health Technology Assessment 2010; 14: no 5.