Patient safety after partial and total knee replacement

摘要

More than 90 000 people in the UK had knee replacements in 2012, according to the National Joint Registry of England and Wales (NJR).1National Joint Registry for EnglandWalesNorthern IrelandNJR 10th annual report 2013. Hemel Hempstead: National Joint Registry, 2013.http://www.njrcentre.org.uk/njrcentre/Portals/0/Documents/England/Reports/10th_annual_report/NJR%2010th%20Annual%20Report%202013%20B.pdfGoogle Scholar The human cost of this expensive surgery is addressed in two articles in The Lancet2Hunt LP Ben-Shlomo Y Clark EM et al.on behalf of the National Joint Registry for England and Wales45-day mortality after 467 779 knee replacements for osteoarthritis from the National Joint Registry for England and Wales: a retrospective observational study.Lancet. 2014; (published online July 8.)http://dx.doi.org/10.1016/S0140-6736(14)60540-7PubMed Google Scholar, 3Liddle AD Judge A Pandit H Murray DW Adverse outcomes after total and unicompartmental knee replacement in 101 330 matched patients: a study of data from the National Joint Registry for England and Wales.Lancet. 2014; (published online July 8.)http://dx.doi.org/10.1016/S0140-6736(14)60419-0PubMed Google Scholar that question conclusions from the NJR, with major consequences for patient safety and the knee replacement industry. The indications for knee replacement remain poorly defined: a patient with a small wear patch seen on MRI is given the same diagnosis as someone whose knee is severely damaged. Both are told they have osteoarthritis. International Classification of Diseases-10 labels osteoarthritis of the knee as gonarthrosis, M17.1, allowing no separation into compartments, and no classification of severity. So, despite being localised to one compartment in most people,4Felson DT Nevitt MC Yang M et al.A new approach yields high rates of radiographic progression in knee osteoarthritis.J Rheumatol. 2008; 35: 2047-2054PubMed Google Scholar because of poor diagnostic criteria, knee osteoarthritis can be validly approached with two different philosophies. Surgeons who deem knee osteoarthritis a disease excise the entire joint, thereby curing the disease and substituting a total knee replacement (TKR). Alternatively, those who deem it to be predictable wear do the smaller operation of partial, or unicompartmental knee replacement (UKR), relining the part that is worn, preserving the rest of the joint surfaces, and, importantly, the anterior cruciate ligament. In TKR, this important structure is routinely excised, which results in reduced ability to walk,5Wiik AV Manning V Strachan RK Amis AA Cobb JP Unicompartmental knee arthroplasty enables near normal gait at higher speeds, unlike total knee arthroplasty.J Arthroplasty. 2013; 28: 176-178Summary Full Text Full Text PDF PubMed Scopus (59) Google Scholar explaining perhaps why TKR is less effective than is total hip replacement,6Ethgen O Bruyere O Richy F Dardennes C Reginster J-Y Health-related quality of life in total hip and total knee arthroplasty. A qualitative and systematic review of the literature.J Bone Joint Surg Am. 2004; 86: 963-974PubMed Google Scholar and why life expectancy might also be affected.7Studenski S Perera S Patel K et al.Gait speed and survival in older adults.JAMA. 2011; 305: 50-58Crossref PubMed Scopus (2976) Google Scholar For patients undergoing either TKR or UKR, if done well, the probability is that this is the last operation that they will need in their lifetime,8Price AJ Svard U A second decade lifetable survival analysis of the Oxford unicompartmental knee arthroplasty.Clin Orthop Relat Res. 2011; 469: 174-179Crossref PubMed Scopus (253) Google Scholar as results from hundreds of thousands of patients now enrolled into national joint registries around the world confirm. Unlike tumour registries, which have strict diagnostic inclusion criteria and use death as an endpoint, joint registries are focused on the outcome of the device: anyone with any amount of joint damage can be admitted, onl