Removal of acetabular bone in resurfacing arthroplasty of the hip

Abstract

We welcome letters to the Editor concerning articles which have recently been published. Such letters will be subject to the usual stages of selection and editing; where appropriate the authors of the original article will be offered the opportunity to reply.Letters should normally be under 300 words in length, doublespaced throughout, signed by all authors and fully referenced. The edited version will be returned for approval before publication. The Oxford medial unicompartmental knee replacement using a minimally-invasive approach Sir, I read with great interest the paper by Pandit et al 1 in the January 2006 issue entitled 'The Oxford medial unicompartmental knee replacement using a minimally-invasive approach'. I wish to congratulate the authors on such a large series of Oxford unicompartmental knee replacements, followed up for a good period of time, with excellent survivorship and clinical results.Although it may not be very obvious in the manuscript (it occupies only one sentence), the way in which the authors reported the Oxford knee score (OKS) deserves careful consideration. The long story of the OKS lies behind that sentence.Since its first description, the OKS has been the subject of rigorous validation, which demonstrated the score to be a short, practical, reliable and valid outcome measure for knee arthroplasty that is also sensitive to clinically-important changes over time. The layout remained essentially the same; 12 questions with five possible answers for each, covering aspects of knee pain and function. The scoring system, however, has kept changing over the past two decades. In its original version as described by the Oxford group, the responses to each question were marked on a scale of 1 to 5. Adding up the marks yields a score of 60 for the worst possible knee, and a score of 12 for the normal, or best possible knee.My first encounter with the OKS was during my work and research at Oswestry, where the scoring system was different. Each question was marked on a scale of 0 to 4, and the total score ranged from 0 to 48. The worst knee therefore attracted a score of 0, and the best score of 48, was achieved by the normal or best possible knee. In their reply to a letter to the editor of the Journal of Bone and Joint Surgery [Br] about this specific scoring method, authors White, Jones and Harcourt commented that they preferred to use the scoring system along a conventional scale, and that this format of scoring the OKS was widely used. They also stressed that authors using the OKS should clearly describe how they use this instrument to avoid any confusion. By reading only the abstract, it was not possible to tell which scale was used in 16 of 24 references which studied or used the OKS. Four papers obviously used the score in its original form, and another four papers,

The clinical and radiological outcomes of hip resurfacing versus total hip arthroplasty: a meta-analysis and systematic review

“…While in this review we found no significant difference in bone removal between the size of the last reamer required to prepare the acetabulum (reiterated in the clinical experiences of Muirhead-Allwood et al (2006), some authors have reported that substantially greater acetabular bone removal occurs with HRS than in conventional THA (Crawford et al 2005, Loughead et al 2006, Naal et al 2009). In this instance, if acetabular failure were to occur, this would be more challenging to revise in a resurfacing implant compared to a conventional implant, as indicated in recent case series (Cuckler 2006, Sandiford et al 2008, Taylor et al 2009, Lachiewicz 2009).…”