sagittal pattello-femoral type [SPFT] in total knee arthroplasty a new parameter

ABSTRACT

Patient's satisfaction commonly goes beyond surgeon's satisfaction after total knee arthroplasty [TKA]. The authors aim at evaluating the correlation between patient's satisfaction and a new radiographic parameter, after TKA, the so-called "sagittal patello-femoral type" [SPFT]. The SPFT corresponds to the relationship between two radiographic lines drawn on the strict lateral knee radiograph the patellar cut line and the posterior femoral cut line. A total of 69 knee replacements were retained for this retrospective study. They all fulfilled a number of inclusion criteria 6 months of minimal follow-up, strict lateral radiograph of the operated knee in monopodal full weight bearing and full extension, and patient reported outcome using the Oxford Knee Score. Two types of SPFT were identified. In Type A, the patellar cut is parallel to the posterior femoral cut, while in type B the two lines are distally convergent. Oxford Knee Score was 78.34% for Type A and 72.34% for Type B; the difference was statistically significant according to Student t-test. The authors believe that SPFT reflects an important aspect of the patello-femoral relationship in TKA, and seems to be correlated to patient's satisfaction; patients with Type A have a higher rate of satisfaction. Nevertheless, the surgical steps the surgeon has to follow, in order to achieve parallel patellar and posterior femoral cuts, need to be clarified in the future