The clinical and cost-effectiveness of total versus partial knee replacement in patients with medial compartment osteoarthritis (TOPKAT): 5-year outcomes of a randomised controlled trial
Authors: David J Beard, Loretta J Davies, Jonathan A Cook, Graeme MacLennan, Andrew Price, Seamus Kent, Jemma Hudson, Andrew Carr, Jose Leal, Helen Campbell, Ray Fitzpatrick, Nigel Arden, David Murray, Marion K Campbell, Karen Barker, Gordon Murray, Hamish Simpson, Donna Dodwell, Simon Donell, Jonathan Waite, Nigel Arden, David Beard, Helen Campbell, Andrew Carr, Cushla Cooper, Loretta Davies, Helen Doll, Seamus Kent, Jose Leal, Ray Fitzpatrick, David Murray, Andrew Price, Jonathan Cook, Marion Campbell, Gordon Fernie, Alison McDonald, Anne Duncan, Mayret Castillo, Francesco Fusco, Akiko Greshon, Kay Holland, Jiyang Li, Elena Rabaiotti, Sandra Regan, Victoria Stalker, Mark Forrest, Graeme MacLennan, Gladys McPherson, Charles Boachie, Diana Collins, Janice Cruden, Sophie Halpin, Beverley Smith, David Torgerson, Chris Maher, Peter Brownson, Mark Mullins Mullins, Jane Blazeby, Ruth Jenkins, Mark Lewis, Witek Mintowt-Czyz, Beverland Beverland, Leeann Bryce, Julie Catney, Ian Dobie, Emer Doran, Seamus O'Brien, Fazal Ali, Heather Cripps, Amanda Whileman, Phil Williams, Julie Toms, Ellen Brown, Gillian Horner, Andrew Jennings, Glynis Rose, Frances Bamford, Wendy Goddard, Hans Marynissen, Haleh Peel, Lyndsey Richards, Amanda Bell, Sunny Deo, Sarah Grayland, David Hollinghurst, Suzannah Pegler, Venkat Satish, Claire Woodruffe, Nick London, David Duffy, Caroline Bennett, James Featherstone, Joss Cook, Kim Dearnley, Nagarajan Muthukumar, Laura Onuoha, Sarah Wilson, Sandhu Banher, Eunice Emeakaroha, Jamie Horohan, Sunil Jain, Susan Thompson, Sarah Buckley, Aaron Ng, Ajit Shetty, Karen Simeson, Julian Flynn, Meryl Newsom, Cheryl Padilla-Harris, Oliver Pearce, James Bidwell, Alison Innes, Winifred Culley, Bill Ledingham, Janis Stephen, Rachel Bray, Hywel Davies, Debbie Delgado, Jonathan Eldridge, Leigh Morrison, James Murray, Andrew Porteous, James Robinson, Matt Dawson, Raj Dharmarajan, David Elson, Will Hage, Nicci Kelsall, Mike Orr, Jackie Grosvenor, SS Maheswaran, Claire McCue, Hemanth Venkatesh, Michelle Wild, Deborah Wilson, Chris Dodd, William Jackson, Pam Lovegrove, Jennifer Piper, Neil Bradbury, Lucy Clark, Stefanie Duncan, Genevieve Simpson, Allister Trezies, Vikram Desai, Cheryl Heeley, Kramer Guy, Rosalyn Jackson, Alan Hall, Gordon Higgins, Michael Hockings, David Isaac, Pauline Mercer, Lindsey Barber, Helen Cochrane, Janette Curtis, Julie Grindey, David Johnson, Phil Turner, David Houlihan-Burne, Briony Hill, Ron Langstaff, Mariam Nasseri, Mark Bowditch, Chris Martin, Steven Pryke, Bally Purewal, Chris Servant, Sheeba Suresh, Claire Tricker, Robert Ashford, Manjit Attwal, Jeanette Bunga, Urjit Chatterji, Susan Cockburn, Colin Esler, Steven Godsiff, Tim Green, Christina Haines, Subash Tandon, Racquel Carpio, Sarah Griffiths, Natalie Grocott, Ian dos Remedios, David Barrett, Phil Chapman-Sheath, Caroline Grabau, Jane Moghul, William Tice, Catherine Trevithick, Rajiv Deshmukh, Mandy Howes, Kimberley Netherton, Dipak Raj, Nikki Travis, Mohammad Maqsood, Rebecca Norton, Farzana Rashid, Alison Raynor, Mark Rowsell, Karen Warner
Journal: The Lancet (2019)

BackgroundLate-stage isolated medial knee osteoarthritis can be treated with total knee replacement (TKR) or partial knee replacement (PKR). There is high variation in treatment choice and little robust evidence to guide selection. The Total or Partial Knee Arthroplasty Trial (TOPKAT) therefore aims to assess the clinical effectiveness and cost-effectiveness of TKR versus PKR in patients with medial compartment osteoarthritis of the knee, and this represents an analysis of the main endpoints at 5 years.MethodsOur multicentre, pragmatic randomised controlled trial was done at 27 UK sites. We used a combined expertise-based and equipoise-based approach, in which patients with isolated osteoarthritis of the medial compartment of the knee and who satisfied general requirements for a medial PKR were randomly assigned (1:1) to receive PKR or TKR by surgeons who were either expert in and willing to perform both surgeries or by a surgeon with particular expertise in the allocated procedure. The primary endpoint was the Oxford Knee Score (OKS) 5 years after randomisation in all patients assigned to groups. Health-care costs (in UK 2017 prices) and cost-effectiveness were also assessed. This trial is registered with ISRCTN (ISRCTN03013488) and ClinicalTrials.gov (NCT01352247).FindingsBetween Jan 18, 2010, and Sept 30, 2013, we assessed 962 patients for their eligibility, of whom 431 (45%) patients were excluded (121 [13%] patients did not meet the inclusion criteria and 310 [32%] patients declined to participate) and 528 (55%) patients were randomly assigned to groups. 94% of participants responded to the follow-up survey 5 years after their operation. At the 5-year follow-up, we found no difference in OKS between groups (mean difference 1·04, 95% CI −0·42 to 2·50; p=0·159). In our within-trial cost-effectiveness analysis, we found that PKR was more effective (0·240 additional quality-adjusted life-years, 95% CI 0·046 to 0·434) and less expensive (−£910, 95% CI −1503 to −317) than TKR during the 5 years of follow-up. This finding was a result of slightly better outcomes, lower costs of surgery, and lower follow-up health-care costs with PKR than TKR.InterpretationBoth TKR and PKR are effective, offer similar clinical outcomes, and result in a similar incidence of re-operations and complications. Based on our clinical findings, and results regarding the lower costs and better cost-effectiveness with PKR during the 5-year study period, we suggest that PKR should be considered the first choice for patients with late-stage isolated medial compartment osteoarthritis.FundingNational Institute for Health Research Health Technology Assessment Programme.