Luo Tao, Zhou Yong-Gang, Sun Jing-Yang
Department of Joint Surgery, the First Center of General Hospital of the People's Liberation Army, Bejing 100853, China.
Zhongguo Gu Shang. 2021 Dec 25;34(12):1147-52. doi: 10.12200/j.issn.1003-0034.2021.12.011.
To investigate whether shifting the femoral opening point and setting a personalized femoral valgus angle can improve the lower limb force line of total knee arthroplasty (TKA) patients with external femoral arch.
From March 2016 to October 2018, 50 patients (55 knees) with osteoarthritis with genu varus deformity combined with external femoral arch for TKA were selected. There were 10 males and 40 females. The age ranged from 63.1 to 80.5 years old, with an average of (67.8±5.8) years old. Forty-five cases were unilateral and 5 cases were bilateral. The osteoarthritis stages of 55 knees were Kellgren-Lawrence grade Ⅲ to Ⅳ; and the course of disease ranged from 2 to 10 years. PreoperativeSpecial Surgery (Hospital for Special Surgery) scores:pain was 15.20±3.52; function was 8.30±2.96;mobility was 10.15±2.85;muscle strength was 4.20±1.95;flexion deformity was 5.50±3.05;stability was 6.15±2.20; total score was 47.93±3.39. The external femoral arch angle ranged from 6.4° to 16.7°, with a mean of (10.63±2.29) °. The tibiofemoral angle ranged from 7.4° to 12.6°, with a mean of (12.04±3.59)°. The anatomical distal femoral angle ranged from 83.10° to 91.20°, with a mean of (84.55± 1.66)°. And the distance from the center of the knee joint to the lower limb line of force ranged from 2.01 to 6.00 cm, with a mean of (3.57±1.12) cm. During the replacement surgery, the femoral opening point and the valgus angle were individually set to obtain a good line of force of the lower limbs.
Before the operation, the distance of femoral opening point ranged from 0.24 to 0.74 cm, with a mean of (0.54±0.10) cm. The distance between the internal and external condyles of the femur ranged from 6.86 to 8.12 cm, with a mean of (7.27±0.27) cm. The preoperative valgus correction angle (VCA) ranged from 7.20° to 13.80°, with a mean of (9.38±1.38) °. The post-correction valgus correction angle' (VCA') ranged from 6.10° to 9.50°, with a mean of (7.36±0.82) °. All patients were followed up, and the duration ranged from 3 to 36 months, with an average of (13.5±5.8) months. All patients obtained good knee function after operation. Three months after operation, HSS scores included pain of 25.30±3.05, function of 18.25±2.05, mobility of 16.05±0.75, muscle strength of 6.20±2.10, flexion deformity of 8.80±1.85, stability of 8.20±1.75; and the total score ranged from 90.00 to 93.00, with an average of 91.82±0.98. The total score was higher than that before operation (=1.728, =0.038). Postoperative X-ray examination showed that there were no signs of loosening, sinking, or osteolysis of the prosthesis. The tibiofemoral angle on the weight-bearing X-ray on the second day after surgery ranged from 1.30° to 4.90°, with a mean of (2.53±0.83) °;the angle ranged from 87.50° to 91.30°, with a mean of (88.73±0.86) °;and the distance from the center of the knee joint to the lower limb line of force ranged from 0.02 cm to 1.20 cm, with a mean of (0.23±0.05) cm; which were improved compared with those before operation (=2.415, =0.019;=1.496, =0.041;=1.912, =0.033).
In TKA combined with external femoral arch, good lower limb force line and knee joint function can be obtained by externally shifting the femoral opening point and setting a personalized femoral valgus angle.
探讨外移股骨开口点并设定个性化股骨外翻角是否能改善合并股骨外弓的全膝关节置换术（TKA）患者的下肢力线。
选取2016年3月至2018年10月行TKA的50例（55膝）膝内翻畸形合并股骨外弓的骨关节炎患者。其中男性10例，女性40例。年龄63.1～80.5岁，平均（67.8±5.8）岁。单侧45例，双侧5例。55膝骨关节炎分期为Kellgren-LawrenceⅢ～Ⅳ级；病程2～10年。术前特种外科医院（Hospital for Special Surgery）评分：疼痛15.20±3.52；功能8.30±2.96；活动度10.15±2.85；肌力4.20±1.95；屈曲畸形5.50±3.05；稳定性6.15±2.20；总分47.93±3.39。股骨外弓角6.4°～16.7°，平均（10.63±2.29）°。胫股角7.4°～12.6°，平均（12.04±3.59）°。股骨远端解剖角83.10°～91.20°，平均（84.55±1.66）°。膝关节中心至下肢力线距离2.01～6.00 cm，平均（3.57±1.12）cm。置换手术中，个体化设定股骨开口点及外翻角，以获得良好的下肢力线。
术前股骨开口点距离0.24～0.74 cm，平均（0.54±0.10）cm。股骨内外髁间距6.86～8.12 cm，平均（7.27±0.27）cm。术前外翻矫正角（VCA）7.20°～13.80°，平均（9.38±1.38）°。矫正后外翻矫正角（VCA'）6.10°～9.50°，平均（7.36±0.82）°。所有患者均获随访，随访时间3～36个月，平均（13.5±5.8）个月。所有患者术后膝关节功能良好。术后3个月，HSS评分：疼痛25.30±3.05，功能18.25±2.05，活动度16.05±0.75，肌力6.20±2.10，屈曲畸形8.80±1.85，稳定性8.20±1.75；总分90.00～93.00，平均91.82±0.98。总分高于术前（=1.728，=0.038）。术后X线检查显示假体无松动、下沉及骨溶解征象。术后第2天负重X线片胫股角1.30°～4.90°，平均（2.53±0.83）°；角度87.50°～91.30°，平均（88.73±0.86）°；膝关节中心至下肢力线距离0.02～1.20 cm，平均（0.23±0.05）cm；与术前比较均有改善（=2.415，=0.019；=1.496，=0.041；=1.912，=0.033）。
在合并股骨外弓的TKA中，通过外移股骨开口点并设定个性化股骨外翻角可获得良好的下肢力线及膝关节功能。
