Antibiotic-loaded articulating cement spacers in twostage revision for infected total knee arthroplasty:individual antibiotic treatment and early results of 21 cases

摘要

Objective:To detail our early experience and technique of a modified two-stage reimplantation protocol using antibiotic-loaded articulating cement spacers (ALACSs) for treatment of late periprosthetic infection after total knee arthroplasty (TKA).Methods:From January 2006 to February 2009,a series of 21 patients (21 knees) with late infected TKAs were treated by radical debridement and removal of all components and cement,and then articulating spacers were implanted using antibiotic-impregnated bone cement.For this purpose,4 g vancomycin powder was mixed with per 40 g cement.Graduated knee motion and partial weight beating activity were encouraged in the interval period.Each patient received an individual systemic organism-sensitive antimicrobial therapy for 4.9 (range,2-8) weeks followed by a second-stage TKA revision.All the patients were regularly followed up using the American Knee Society Scoring System.Results:Each case underwent a successful two-stage exchange and had infection eradicated,none had recurrent infection after an average of 32.2 (range,17-54) months of follow-up.Preoperatively,the mean knee score was 53.5 points,function score was 27.3 points,pain score was 25.7 points,range of motion (ROM) was 82.0°,extensor lag was 2°.Between stages,the mean knee score was increased to 61.3 points,function score to 45 points,pain score to 35 points,ROM to 88.2°,and extensor lag to 3.4°.At final follow-up,the mean knee score was further increased to 82.1 points,function score to 74.5 points,pain score to 42.1 points,ROM to 94.3°,and knee extension lag to 1.9°.Theinterval period was 11.5 (range,6-32) weeks.The amount of　bone loss was unchanged between stages.No patient developed noticeable dysfunction of the liver or kidney or　other complications such as impaired wound healing,deep　venous thrombosis,pulmonary embolism,cerebrovascular　accidents,etc.Conclusions:Treating infected TKA with ALACS　avoids spacer-related bone loss,preserves knee function　between stages,and eradicates infection effectively without significant complications.The early clinical results are　inspiring.The authors believe that radical and repeated (if　needed) debridement,individual application of systemic　antibiotics,and reasonable timing judgement upon the secondary revision are all key factors related to a successful　outcome with two-stage reimplantation procedure for infected TKA.