Pre-operative radiological measurement of femoral rotation for prosthetic positioning in total knee arthroplasty.

Savin, Liliana; Botez, Paul; Mihailescu, Dan; Predescu, Vlad; Grierosu, Carmen

<bold>Purpose: </bold>This study outlines the benefits of the seated view radiograph of the knee in evaluation of the pre-operative individual distal femoral torsion (DFT) and for the follow-up of the post-operative rotational positioning of the femoral component in total knee arthroplasty.<bold>Methods: </bold>Study on 20 patients who underwent total knee arthroplasty and the correlation between the DFT measured before surgery with this radiology view, the intra-operative external rotation (ER) necessary for the parallel positioning of the femoral component with the transepicondylar axis (TEA) and the post-operative femoral rotational alignment of the prosthesis on the same view.<bold>Results: </bold>In 90 % of cases the values of internal DFT were between -1(0) and -8(0), while the mean value of the internal rotation (IR) was -4.45(0). The mean value of the ER applied to the posterior bone resection was 4.25(0) (0(0)-7(0)), showing a statistically significant correlation between the pre-operative measurement and the intra-operative one of the posterior condylar angle (PCA) (r = 0.890, p = 0.000). Residual internal femoral malrotation has been identified in four cases, its mean value being 0.4(0). In three patients the pre-operative value of the PCA was higher than the intra-operative one and an internal malrotation of the post-operative femoral component was observed.<bold>Conclusions: </bold>The results are encouraging for the further use of this pre-operative view with the premises of increasing the accuracy of prosthetic positioning and reducing the mechanical complications.

KNEE radiography; RADIOGRAPHY; TOTAL knee replacement; CONDYLARTHRA; KNEE diseases; ARTIFICIAL joints; COMPUTED tomography; FEMUR; KNEE; ROTATIONAL motion; ANATOMY

International Orthopaedics, 2016, Vol 40, Issue 9, p1855

0341-2695

Academic Journal

10.1007/s00264-015-3110-2