Component placement failures in total knee arthroplasty

Objective: The common cause of aseptic loosening after total knee arthroplasty is component malalignment during surgical procedure. In an attempt to evaluate component malaligment we performed this study. Materials and methods: 205 knees of 172 patients who were operated between 2002-2013 in Adnan Menderes University department of orthopedics and traumatology were evaluated. Pre and postoperative anatomic axis, alpha (α), beta (β), gama(γ), delta(δ) angles measured on pre and postoperative x-rays. Anterior, posterior, medial and lateral displacements of tibial components were also measured. Component coverage ratio, posterior tibial slope, Insall-Salvati index, Blackburne-Peel ratio, the change in joint line were measured. The number of patients that have femoral notching and lateral retinacular release were evaluated. Results: There was 148 female and 24 male patients. The mean age of the patients was 66,68 years. The tibiofemoral anatomical axis was measured as 7,09° varus preoperatively and 3,07° valgus postoperatively. Postoperative tibiofemoral axis and alpha angle was higher in patients who has valgus knees preoperatively than who has varus knees. Postoperative Insall-Salvati and Blackburne-Peel indexes were increased in varus knees. Reverse tibial slope was obtained in 6 patients. Sixty tibial components covered tibial plato completely where as12 tibial components overhanged on medial site and 68 tibial components overhanged on lateral site. There were 33 knees with femoral notching. Discussion: Even many guides used during total knee arthroplasty surgical procedure, many major and minor mistakes can be made during operation that may effect postoperative survival of the prothesis and patient satisfaction. Key Words: Total knee arthroplasty, Component, Alpha angle, Beta angle.