Roentgen Stereophotogrammetric Analysis (RSA) to Evaluate Fixation of Biofoam Advance Total Knee Arthroplasty Components

Hip and knee replacement arthroplasty are profoundly successful operative interventions, however, some joint replacements do fail and the life expectancy of a hip or knee arthroplasty is finite. This fact has largely been responsible for the continued development of new devices and techniques for joint arthroplasty surgery. Unfortunately, the introduction of new technologies and devices is not a benign process, and even subtle changes to existing implants can have a disastrous effect on patient outcome. The fact that new technologies and devices can lead to poor results has led some authors to advocate a phased introduction of new technologies. A key component of the phased introduction approach advocates the use of roentgen stereophotogrammetric analysis (RSA) early in the testing process. RSA is a highly accurate radiographic technique developed in Lund, Sweden and has for some time been the gold standard in Europe for assessing the stability of implants within bone. The purpose of this study is to utilize RSA to elucidate the migration patterns of the foam metal backed Advance Knee Arthroplasty components during the first 2 years postoperatively and to determine in what proportion of cases adequate fixation is achieved. In addition outcome measures will be recorded to quantify changes in functional status of subjects after surgery and bone mineral density will be monitored to quantify bone in-growth around the implant. Migration patterns will be compared to results obtained from previous studies of uncemented and cemented total knee arthroplasty components conducted at this centre.