Articular cartilage is aesthetically beautiful, functions to a specification that is not reproducible by any synthetic material, and can move wear-free for a century. As with anything seemingly perfect, it has a major flaw; it is incapable of meaningful self-repair and a defect of over 0.9cm will degenerate.1 Repair of articular cartilage is a subject that has challenged orthopaedic surgeons forever. We have made progress, but the scientific challenges of extensive damage of joint surfaces, treatment of some joints with available techniques, and salvage situations remain. There are exciting and emerging treatments; stem cells, combination and augmented therapies etc.
Cell-based cartilage repair is at a crossroad, and not due to the science but the economics. Cell therapy companies have invested vast sums of money in objectively-conducted multicentre RCTs to prove the outcome of patients receiving cell therapy for isolated articular cartilage lesions do better than patients who receive microfracture.2,3 This was necessary to gain EU licensing of their treatments. Cell therapy companies want to recoup the cost of these studies and continue to innovate, hospitals doing clinical cell therapy need Human Tissue Authority Licences, there are lab costs, cell characterisation and viability assays, transport costs etc; the cost of cell therapy treatment is considered high. However, cell therapy is currently equivalent to the cost episode of having a knee replacement, if you include hospital stay and allied health professional costs. If the cell therapy companies raise the cost of treatment, now they have invested heavily to gain some evidence of the efficacy of their products, they risk pricing themselves and their therapy out of reach of many healthcare systems and denying some patients the opportunity to access the very therapy they have just shown to be effective.
This throws up a myriad of ethical questions. A young adult with a symptomatic isolated articular cartilage defect can have equivalent pain and loss of function to a person with osteoarthritis of the knee.4 Would anybody suggest doing a Priddie drilling or an arthrodesis for end-stage primary osteoarthritis of the knee when we have evidence for better outcomes with arthroplasty? Should cartilage defect patients also be offered evidence-based best treatment where this evidence is available? In my view they should, but it is not realistic or justifiable at any cost industry determines. The MHRA regulates ‘hospital exemption’ status for processing cells locally, this is very difficult to obtain and there is only one in the UK. Perhaps more competition would lower prices, but few start-up or smaller companies can afford the funds necessary to run the RCTs to get EU licensing. Cartilage repair is at a crossroad; what can we as surgeons do to strive for best treatment for our patients? A few suggestions: 1. Evaluate the evidence available; to this aim an industry-free open UK Cartilage Consensus meeting has been convened, free to attend for any interested surgeon (www.trauma.co.uk). The evidence will be examined and a consensus paper and algorithm for isolated articular cartilage defects developed. 2. Collect outcome data; a cartilage repair registry is in development, which will also allow previous patients to enter. 3. Engage with patients, regulatory bodies, government bodies, industry and healthboards. 4. Engage in clinical trials with colleagues, and pre-clinical studies with scientists where possible. Responsible innovation for patient benefit doesn’t come cheap or hassle free, but it’s the right thing to do.
Leela C Biant, Consultant Trauma & Orthopaedic Surgeon, The Royal Infirmary of Edinburgh
1. Guettler JH, Demetropoulos CK, Yang KH, Jurist KA. Osteochondral defects in the human knee: influence of defect size on cartilage rim stress and load redistribution to surrounding cartilage. Am J Sports Med 2004;32;1451–1458.
2. Saris D, Price A, Drogset JO et al. Prospective, randomized, controlled trial: response rates to matrix-induced autologous chondrocyte implant (MACI) versus microfracture (MFX) by lesion characteristics. (www.sportsmed.org date last accessed 27 February 2014)
3. Vanlauwe J1, Saris DB, Victor J, Almqvist KF, Bellemans J, Luyten FP; TIG/ACT/01/2000&EXT Study Group Five-year outcome of characterized chondrocyte implantation versus microfracture for symptomatic cartilage defects of the knee: early treatment matters. Am J Sports Med 2011;39:2566-74.
4. Heir S, Nerhus TK, Røtterud JH, Løken S, Ekeland A, Engebretsen L, Arøen A. Focal cartilage defects in the knee impair quality of life as much as severe osteoarthritis: a comparison of knee injury and osteoarthritis outcome score in 4 patient categories scheduled for knee surgery. Am J Sports Med 2010;38:231-7.
Read highlights from the 7th MedActa International Symposium