+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Obesity should not be considered a contraindication to medial Oxford UKA: long-term patient-reported outcomes and implant survival in 1000 knees

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.



          Some health providers ration knee arthroplasty on the basis of body mass index (BMI). There is no long-term data on the outcome of medial mobile-bearing unicompartmental knee arthroplasty (UKA) in different BMI groups. This study aimed to determine the effect of patient body mass index (BMI) on patient-reported outcomes and long-term survival of medial UKA in a large non-registry cohort. Our hypothesis is that increasing BMI would be associated with worse outcomes.


          Data were analysed from a prospective cohort of 1000 consecutive medial mobile-bearing Oxford UKA with mean 10-year follow-up. Patients were grouped: BMI < 25, BMI 25 to < 30, BMI 30 to < 35 and BMI 35+. Oxford Knee Score (OKS) and Tegner Activity Score were assessed at 1, 5 and 10 years. Kaplan–Meier survivorship was calculated and compared between BMI groups.


          All groups had significant improvement in OKS and Tegner scores. BMI 35 + kg/m 2 experienced the greatest overall increase in mean OKS of 17.3 points ( p = 0.02). There was no significant difference in ten-year survival, which was, from lowest BMI group to highest 92%, 95%, 94% and 93%.


          There was no difference in implant survival between groups, and although there was no consistent trend in postoperative OKS, the BMI 35+ group benefited the most from UKA. Therefore, when UKA is used for appropriate indications, high BMI should not be considered to be a contraindication. Furthermore rationing based on BMI seems unjustified, particularly when the commonest threshold (BMI 35) is used.

          Level of evidence


          Related collections

          Most cited references 31

          • Record: found
          • Abstract: not found
          • Article: not found

          Nonparametric Estimation from Incomplete Observations

           E. Kaplan,  Paul Meier (1958)
            • Record: found
            • Abstract: found
            • Article: not found

            Rating systems in the evaluation of knee ligament injuries.

             Y Tegner,  J Lysholm (1985)
            Many different methods of evaluating disability after knee ligament injury exist. Most of them differ in design. Some are based on only patients' symptoms. Other include patients' symptoms, activity grading, performance in a test, and clinical findings. The rating in these evaluating systems can be either numerical, as in a score, or binary, with yes/no answers. Comparison between a symptom-related score and a score of more complex design showed that the symptom-related score gave a more differentiated picture of the disability. It was also shown that the binary rating system gave less detailed information than a score and that differences in a binary rating can depend on at what level the symptoms are regarded as "significant." A new activity grading scale, where work and sport activities were graded numerically, was constructed as complement to the functional score. When evaluating knee ligament injuries, stability testing, functional knee score, performance test, and activity grading are all important. However, the relative importance varies during the course of treatment, and therefore they should not all be included in one and the same score.
              • Record: found
              • Abstract: found
              • Article: not found

              The use of the Oxford hip and knee scores.

              The Oxford hip and knee scores have been extensively used since they were first described in 1996 and 1998. During this time, they have been modified and used for many different purposes. This paper describes how they should be used and seeks to clarify areas of confusion.

                Author and article information

                Knee Surg Sports Traumatol Arthrosc
                Knee Surg Sports Traumatol Arthrosc
                Knee Surgery, Sports Traumatology, Arthroscopy
                Springer Berlin Heidelberg (Berlin/Heidelberg )
                25 October 2018
                25 October 2018
                : 27
                : 7
                : 2259-2265
                [1 ]ISNI 0000 0004 1936 8948, GRID grid.4991.5, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, , University of Oxford, ; Windmill Road, Oxford, OX3 7LD UK
                [2 ]ISNI 0000 0001 0440 1440, GRID grid.410556.3, Nuffield Orthopaedic Centre, , Oxford University Hospitals NHS Foundation Trust, ; Oxford, UK
                © The Author(s) 2018

                Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

                Funded by: FundRef, Biomet;
                Funded by: FundRef, Zimmer;
                Custom metadata
                © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2019


                Comment on this article