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An improvement in a restraint mechanism of the APG mobile bearing prosthesis is needed tominimize the development of complications with regard to a combination of this design andpatient factors.Thursday, October 7, 2010, 11:10-11:50Session A4: Hip ResurfacingLong Term Outcome in Modern Hip Resurfacing Arthroplasty. a Minimumof 10 Years Follow Up.*Peter Lewis - Cwm Taf Local Health Board - South Wales, UKKemi Alo - New cross hospital - wolverhampton, UKJag Chakravarthy - new cross hospital - Wolverhampton, UKEric Isbister - New Cross Hospital - wolverhampton, UK*Email: pete_lewis5@hotmail.comThe modern generation of hip resurfacing arthroplasties was developed in the early 1990’s withone of the original designs being the McMinn Resurfacing Total Hip System. This was a hybridmetal on metal prosthesis, with a smooth hydroxyapetite coated press fit mono block cobaltchrome shell with a cemented femoral component. Although no longer produced in this form,lessons may be learned from this original series of components. With metal on metalresurfacing arthroplasty now facing criticisms and concerns with regard function, bonepreservation capability and soft tissue issues such as ‘pseudotumors’, it is the aim of this longtermstudy to assess the outcome and survival of an original series of resurfacing arthroplasties.27 resurfacing arthroplasties were performed in 25 consecutive patients between June 1994 andNovember 1996. 16 right hips and 11 left were performed in 14 female patients and 11 malepatients. The average age at the time of surgery was 50.5 years (SD 7.9, range 30-63). Allsurgeries were performed by a single surgeon using a posterior lateral approach. Following theinitial early care, each patient received bi-annual follow up along with open access to the clinicwith any concerns or complications. A retrospective review of the case notes was conducted andoutcome scores retrieved from a prospectively updated database. Radiographs were analyzedand a Kaplan Meier survival chart was constructed for the group.At latest review 3 patients have died (5yrs, 8yrs and 13.8yrs) and 1 patient has been lost tofollow up (5yrs). 7 resurfacings have required revision, all due to acetabular loosening, at amean follow up of 7 years 11months (SD 2.03years, range 4-10). Metallosis was documented in4 of the revision cases, however no extensive soft tissue inflammation or ‘pseudotumor’identified. The mean follow up of the remaining 16 hips is 12years and 10months (SD12.8months, Range 10.4yrs-14.0 years). The Kaplan Meier survival at a minimum follow up of10 years is 75.8% (95% CI 0.67-0.95). Mean Oxford hip scores at latest follow up was 20.6 (SD8.8, range 12-38). There was no significant difference between cup inclination angles for thesurviving cohort and those who required a revision procedure with mean cup inclinations of52.5 (SD 5.5, range 45-60) and 58 degrees respectively (SD 9.1, range 50-70)(p=0.255).This original series of hip resurfacings, with up to 14 years follow up, shows a survival of 76%at the minimum follow up of 10 years. All failures were due to loosening of the smooth backedfile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]