Abstract
Background
The Oxford knee is a unicompartmental implant featuring a mobile-bearing polyethylene component with excellent long-term survivorship results reported by the implant developers and early adopters. By contrast, other studies have reported higher revision rates in large academic practices and in national registries. Registry data have shown increased failure with this implant especially by lower-volume surgeons and institutions.
Questions/purposes
In the setting of a high-volume knee arthroplasty practice, we sought to determine (1) the failure rate of the Oxford unicompartmental knee implant using a failure definition for aseptic loosening that combined clinical features, plain radiographs, and scintigraphy, and (2) whether increased experience with this implant would decrease failure rate, if there is a learning curve effect.
Methods
Eighty-three Oxford knee prostheses were implanted between September 2005 and July 2008 by the principal investigator. Radiographic and clinical data were available for review for all cases. A failed knee was defined as having recurrent pain after an earlier period of recovery from surgery, progressive radiolucent lines compared with initial postoperative radiographs, and a bone scan showing an isolated area of uptake limited to the area of the replaced compartment.
Results
Eleven knees in this series failed (13%); Kaplan-Meier survivorship was 86.5% (95% CI, 78.0%–95.0%) at 5 years. Failure occurrences were distributed evenly over the course of the study period. No learning curve effect was identified.
Conclusions
Based on these findings, including a high failure rate of the Oxford knee implant and the absence of any discernible learning curve effect, the principal investigator no longer uses this implant.
Level of Evidence
Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
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References
Baker P, Jameson S, Critchley R, Gregg P, Deehan D. Center and surgeon volume influence the revision rate following unicondylar knee replacement: an analysis of 23,400 medial cemented unicondylar knee replacements. J Bone Joint Surg Am. 2013;95:702–709.
Berbari E, Mabry T, Tsaras G, Spangehl M, Erwin PJ, Murad MH, Steckelberg J, Osmon D. Inflammatory blood laboratory levels as markers of prosthetic joint infection: a systematic review and meta-analysis. J Bone Joint Surg Am. 2010;92:2102–2109.
Berend KR, Lombardi AV Jr. Liberal indications for minimally invasive Oxford unicondylar arthroplasty provide rapid functional recovery and pain relief. Surg Technol Int. 2007;16:193–197.
Chou DT, Swamy GN, Lewis JR, Badhe NP. Revision of failed unicompartmental knee replacement to total knee replacement. Knee. 2012;19:356–359.
Choy WS, Kim KJ, Lee SK, Yang DS, Lee NK. Mid-term results of Oxford medial unicompartmental knee arthroplasty. Clin Orthop Surg. 2011;3:178–183.
Dervin GF, Carruthers C, Freibel RJ, Gianchino AA, Kim PR, Thurston PR. Initial experience with the Oxford unicompartmental knee arthroplasty. J Arthroplasty. 2011;26:192–197.
Ericsson KA, Krampe RT, Tesch-Romer C. The role of deliberate practice in the acquisition of expert performance. Psychol Rev. 1993:100:363–406.
Goodfellow JW, O’Connor JJ, Murray DW. A critique of revision rate as an outcome measure: re-interpretation of knee joint registry data. J Bone Joint Surg Br. 2010;92:1628–1631.
Gulati A, Chau R, Pandit HG, Gray H, Price AJ, Dodd CA, Murray DW. The incidence of physiological radiolucency following Oxford unicompartmental knee replacement and its relationship to outcome. J Bone Joint Surg Br. 2009;91:896–902.
Hamilton WG, Ammeen D, Engh CA Jr, Engh GA. Learning curve with minimally invasive unicompartmental knee arthroplasty. J Arthroplasty. 2010;25:735–740.
Heller S, Fenichel I, Salai M, Luria T, Velkes S. The Oxford unicompartmental knee prosthesis for the treatment of medial compartment knee disease: 2 to 5 year follow-up. Isr Med Assoc J. 2009;11:266–268.
Kalra S, Smith TO, Berko B, Walton NP. Assessment of radiolucent lines around the Oxford unicompartmental knee replacement: sensitivity and specificity for loosening. J Bone Joint Surg Br. 2011;93:777–781.
Kaplan EL, Meier P. Nonparametric estimation from incomplete observations. J Am Stat Assoc. 1958;53:457–481.
Kendrick BJ, Simpson DJ, Kapstein BL, Valstar ER, Gill HS, Murray DW, Price AJ. Polyethylene wear of mobile-bearing unicompartmental knee replacement at 20 years. J Bone Joint Surg Br. 2011;93:470–475.
Kuipers BM, Kollen BJ, Bots PC, Burger BJ, Van Raay JJ, Tulp NJ, Verheyen CC. Factors associated with reduced early survival in the Oxford phase III medial unicompartmental knee replacement. Knee. 2010;17:48–52.
Lewold S, Goodman S, Knutson K, Robertson O, Lidgren L. Oxford meniscal bearing knee versus the Marmor knee in unicompartmental arthroplasty for arthrosis: a Swedish multicenter survival study. J Arthroplasty. 1995;10:722–731.
Mercier N, Wimsey S, Saragaglia D. Long-term clinical results of the Oxford medial unicompartmental knee arthroplasty. Int Orthop. 2010;34:1137–1143.
Murray DW, Goodfellow JW, O’Connor JJ. The Oxford medial unicompartmental arthroplasty: a ten-year survival study. J Bone Joint Surg Br. 1998;80:983–989.
New Zealand Orthopaedic Association. The New Zealand Joint Registry. Thirteen year report: January 1999–December 2012. Available at: www.nzoa.org.nz/nz-joint-registry. Accessed July 3, 2013.
Pandit H, Jenkins C, Barker K, Dodd CA, Murray DW. The Oxford medial unicompartmental knee replacement using a minimally-invasive approach. J Bone Joint Surg Br. 2006;88:54–60.
Pearse AJ, Hooper GJ, Rothwell A, Frampton C. Survival and functional outcome after revision of a unicompartmental to a total knee replacement: the New Zealand National Joint Registry. J Bone Joint Surg Br. 2010;92:508–512.
Price AJ, Svard U. A second decade lifetable survival analysis of the Oxford unicompartmental knee arthroplasty. Clin Orthop Relat Res. 2011;469:174–179.
Rea P, Short A, Pandit H, Price AJ, Kyberd P, Beard DJ, Gill HS, Murray DW. Radiolucency and migration after Oxford unicompartmental knee arthroplasty. Orthopedics. 2007;30(5 suppl):24–27.
Robertsson O, Knutson K, Lewold S, Lidgren L. The routine of surgical management reduces failure after unicompartmental knee arthroplasty. J Bone Joint Surg Br. 2001;83:45–49.
Schroer WC, Calvert GT, Diesfeld PJ, Reedy ME, LeMarr AR. Effects of increased surgical volume on total knee arthroplasty complications. J Arthroplasty. 2008;23(6 suppl 1):61–67.
Schroer WC, Stormont DM, Pietrzak WS. Seven-year survivorship and functional outcomes of the high-flexion Vanguard complete knee system. J Arthroplasty. 2013 May 20. pii: S0883-5403(13)00311-2 [Epub ahead of print].
Vorlat P, Putzeys G, Cottenie D, Van Isacker T, Pouliart N, Handelberg F, Casteleyn PP, Gheysen F, Verdonk R. The Oxford unicompartmental knee prosthesis: an independent 10-year survival analysis. Knee Surg Sports Traumatol Arthrosc. 2006;14:40–45.
Zermatten P, Munzinger U. The Oxford II medial unicompartmental knee arthroplasty: an independent 10-year survival study. Acta Orthop Belg. 2012;78:203–209.
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One of the authors (WCS), or a member of his or her immediate family, certifies that he has received or will receive payments or benefits, during the study period an amount less than USD 10,000 from Biomet, Inc, (Warsaw, IN, USA). One of the authors (CLB), or a member of his or her immediate family, certifies that he has received or will receive payments or benefits, during the study period, an amount less than USD 10,000 from Wright Medical (Arlington, TN, USA); an amount less than USD 10,000 from DJO/Conformis (Vista, CA, USA); and an amount less than USD 10,000 from J & J/Stryker (Kalamazoo, MI, USA).
All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request.
Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.
This study was performed at the St Louis Joint Replacement Institute, St Louis, MO.
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Schroer, W.C., Barnes, C.L., Diesfeld, P. et al. The Oxford Unicompartmental Knee Fails at a High Rate in a High-volume Knee Practice. Clin Orthop Relat Res 471, 3533–3539 (2013). https://doi.org/10.1007/s11999-013-3174-5
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DOI: https://doi.org/10.1007/s11999-013-3174-5