Patient-specific guiding (PSG) is a relatively new technique for aligning a total knee arthroplasty (TKA). Limited data exist on the precise accuracy of the technique. The purpose of this study is to investigate whether there was significant difference between the alignment of the individual femoral and tibial components (in all three anatomical planes) as calculated pre-operatively and the actually achieved alignment Twenty-six patients were included. Software permitted matching of the pre-operative MRI-scan (and therefore calculated prosthesis position) to a pre-operative full-leg CT-scan. After surgery a post-operative full-leg CT-scan could be superimposed onto the pre-operative CT-scan to accurately determine deviations from planning (see figure 1 and 2). This 3D-technique has an accuracy of 0.7–1.0 degrees.Background:
Methods:
The full leg x-ray is a widely used imaging modality for post-operative assessment of total knee replacement (TKR). However, these assessments require controlled conditions and precise measuring in order to be accurate. inter-observer reliability remains a matter of concern as well. This study examines whether intersurgeon differences are significant. Post-operative lateral and full-leg frontal x-rays of 26 patients were assessed by 6 surgeons according to a strict measuring protocol. Four measurements (Figure 1 and 2) were taken of which two were on the femur (Femoral Varus Angle FVA and Femoral Flexion Angle FFA) and two, on the tibia (Tibial Varus Angle TVA; Tibial Slope Angle TSA). A random effects, two-way ANOVA was performed on the data using Minitab (v 16.0, Minitab Inc., Pennsylvania, USA) to determine whether a surgeon has influence on the results (α = 0.05). Intra-class correlation coefficients (ICC) and standard error of measurements (SEM) resulting in smallest detectable changes (SDC) were also calculated [1].Background
Method
