Medialization of the patella component in total knee arthroplasty in Chinese adults / 中华骨科杂志

ABSTRACT

Objective To investigate the effect of medialization of the patella component on patel-lar-femoral track and clinic result in patellar resurfacing arthroplasty in Chinese adults.Methods From September2001to March2002,patellar-femoral track of medialized patella component in total75consecu-tive total knee arthroplasties were checked with"no thumb test"sign during patellar resurfacing as well as af-ter patellar resurfacing.The patients consisted of 8males(14knees)and40females(61knees).The average age of the patients was66.2years old(ranging from62to79years old).The preoperative diagnosis of the knees were osteoarthritis96%,rheumatoid arthritis4%.There were65varus knees,9nomal knees and1val-gus knee.Eight knees had patellar subluxation or bad patellar-femoral track before arthroplasty.Results Patellar-femoral track were checked with"no thumb test"sign after putting femoral and tibial tray before patellar resurfacing,69of 75knees could reach"no thumb test".After resurfacing and medialization of patella com ponent by2to5mm,all69knees could still reach"no thumb test".But 6knees were ineffectual.After resur facing and medialization of patella component by4to8mm,5of the6knees could reach"no thumb test",the remained one reached"no thumb test"and was of 15?valgus after lateral release.Average flexion of total75knees was108.6?(from90?to115?)two weeks after operation,and increased to116.5?(from95?to125?)after an average follow-up of 15months,ranging from12to18months.No case had patellar fracture insta bility and patellar subluxation.Conclusion Medialization of the patella component in total knee arthro plasty can improve patellar-femoral track,reduce requirement of release of patellar lateral retinac-ulum,decrease patellar-femoral joint complication and increase survival ship of prosthesis.