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Kingdom*Email: strachanrk@yahoo.comDegenerate chondral surfaces can be assessed in many ways, but arthroscopy is often performedwithout proper categorisation, mapping, zoning or sizing of lesions. Progression of disease inun-resurfaced compartments is well-recognised to occur, but is only one of several failuremechanism in partial knee replacement.A validated ‘Functional Zone’ mapping method was used to document articular surfacedamage in 250 sequential cases of knee arthroscopy in patients over the age of 40. Size, shape,location and severity of each chondral lesion were noted using the Outerbridge classification.Analysis determined rates of involvement of particular compartments and assessed potential forpartial replacement or local treatment and also to consider the risk of future progression.Radiographs including antero-posterior standing, postero-anterior flexion views (Rosenberg),lateral and skyline views were graded (Kellgren and Lawrence) and compared with thearthroscopic findings.Our results showed that out of the 210 knees with Grade 3 or greater damage 13.3% ofknees showed ‘isolated’ medial disease of Outerbridge Grade 3 or worse. Isolated lateraldisease was noted in 1.4%, patello-femoral disease in 24.3%, bi-compartmental (Medial/PFJ)disease in 30.9% with tibio-femoral and tri-compartmental disease seen in 15.2%. Thecombination of lateral and patello-femoral disease was seen in 14.8%. Provided that Grade 1and 2 changes (which were found in other compartments in high percentages) were ignored andACL status considered, this information seemed to indicate that at the time these procedureswere performed, 13.3% of cases were suitable for a medial uni-compartmental device, withsub-analysis of lesion sizes indicating that 17 out of 28 cases (60.7%) were suitable for alocalised resurfacing. Lateral uni-compartmental replacement seemed suitable for only 1.4%,patello-femoral replacement in 24.3%, bi-compartmental in 30.9% and total knee replacementin 30%. The mean age for partial resurfacing was 53years and 59 years for total jointreplacements.Radiological analysis found that the antero-posterior standing views had only 66%sensitivity and 73% specificity for the presence of Grade 3 changes or worse in the medialcompartment in comparison with Rosenberg views having a sensitivity of 73% and a specificityof 83%. Skyline views had a sensitivity of 56% and 100% specificity.This study indicates that a large proportion of cases may be suited to local and limitedresurfacing. Cases suitable for Patello-femoral and Bi-compartmental replacements were verycommon, but with the patella-femoral joint’s tendency to be more forgiving in terms ofsymptoms, meaning that indications for uni-compartmental replacement might well be muchhigher than the arthroscopic findings suggested. On the other hand, the presence of high levelsof Grade 1 and 2 changes in other compartments seems to indicate a need for cautionparticularly in younger patients. This study also indicates a need for better methods ofassessing local cartilage health such as enhanced MRI scanning or spectroscopy.Friday, October 8, 2010, 8:00-8:30Session A10: Bearings and Tribologyfile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]