Radiographic Measurement of Femoral Lateral Bowing and Distal Femoral Condyle Resection Thickness： Variances and Effects on Total Knee Arthroplasty Planning  

作　　者：Pei-Hui Wu Zhi-Qi Zhang Ming-Hui Gu Xiao-Yi Zhao Yan Kang Wei-Ming Liao Ming Fu 

机构地区：[1] Department of Joint Surgery, The 1st Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China [2]Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Guangzhou, Guangdong 510080, China

出　　处：《Chinese Medical Journal》2017年第21期2557-2562,共6页中华医学杂志（英文版）

摘　　要：Background：Accurate evaluation of the plain radiography of lower limb is critical for preoperative planning of total knee arthroplasty （TKA）. We aimed to investigate the effect of femoral lateral bowing and rotation on the radiographic measurements of distal femoral condyle resection thickness （DRT） and the distal femoral resection valgus angle （FVA）. Methods： We analyzed 246 three-dimensional femoral models generated from computed tomography images of 123 patients, acquiring projected contours in seven positions – 20° and 10° internal rotation; 0° rotation; 10°, 20°, 30°, and 40° external rotation – for each model. Medial and lateral condyle DRTs, femoral shaft lateral bowing angle （FBA）, and distal FVA were determined for each position. Linear mixed effect model was used to determine the effect of degree of femur rotation on repeated measurements of DRT or FVA. Results： FBA significantly affected the FVA and DRT （Pearson＇s R = 0.767 and -0.408, respectively; P 〈 0.000）. Samples were divided into three groups according to the FBA measured in neutral position： FBA 〈0°： DRT 3.75 ± 1.30 mm, FVA 4.53° ± 1.27°; FBA 〉0° but 〈3°： DRT 3.39 ± 1.31 mm, FVA 5.92° ± 1.31°; FBA 〉3°： DRT 2.22 ± 1.31 mm, FVA 7.37° ± 1.31°. From simulated 20° internal rotation to 40° external rotation in each femoral model, the average variation ranges of radiographically measured DRT, FVA, and FBA were 0.50 ± 0.28 mm, 2.93° ± 0.96°, and 10.33° ± 1.90°, respectively, with no significant differences among the FBA groups. The degree of femoral rotation significantly affected the FVA （F = 62.148, P 〈 0.000）, whereas there was no effect on condyle resection thickness （F = 0.4705, P = 0.494）. Conclusions： Axial femoral rotation has less effect on radiographic measurements of differences in the DRT than on those of the distal FVA.Background：Accurate evaluation of the plain radiography of lower limb is critical for preoperative planning of total knee arthroplasty （TKA）. We aimed to investigate the effect of femoral lateral bowing and rotation on the radiographic measurements of distal femoral condyle resection thickness （DRT） and the distal femoral resection valgus angle （FVA）. Methods： We analyzed 246 three-dimensional femoral models generated from computed tomography images of 123 patients, acquiring projected contours in seven positions – 20° and 10° internal rotation; 0° rotation; 10°, 20°, 30°, and 40° external rotation – for each model. Medial and lateral condyle DRTs, femoral shaft lateral bowing angle （FBA）, and distal FVA were determined for each position. Linear mixed effect model was used to determine the effect of degree of femur rotation on repeated measurements of DRT or FVA. Results： FBA significantly affected the FVA and DRT （Pearson＇s R = 0.767 and -0.408, respectively; P 〈 0.000）. Samples were divided into three groups according to the FBA measured in neutral position： FBA 〈0°： DRT 3.75 ± 1.30 mm, FVA 4.53° ± 1.27°; FBA 〉0° but 〈3°： DRT 3.39 ± 1.31 mm, FVA 5.92° ± 1.31°; FBA 〉3°： DRT 2.22 ± 1.31 mm, FVA 7.37° ± 1.31°. From simulated 20° internal rotation to 40° external rotation in each femoral model, the average variation ranges of radiographically measured DRT, FVA, and FBA were 0.50 ± 0.28 mm, 2.93° ± 0.96°, and 10.33° ± 1.90°, respectively, with no significant differences among the FBA groups. The degree of femoral rotation significantly affected the FVA （F = 62.148, P 〈 0.000）, whereas there was no effect on condyle resection thickness （F = 0.4705, P = 0.494）. Conclusions： Axial femoral rotation has less effect on radiographic measurements of differences in the DRT than on those of the distal FVA.

关 键 词：Distal Femoral Resection Radiographic Measurement： Total Knee Arthroplasty Valgus Angle 

分 类 号：R-4[医药卫生]