Sun Zhenhui, Cao Jiangang, Tian Mengqiang, Wang Lei, Sun Yunbo, Zhang Yu, Liu Jun
Department of Orthopedics, the People's Hospital of Tianjin, Tianjin, 300121, P.R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2011 Jan;25(1):38-41.
To analyze the effect of the distal femoral flexion angle (DFFA) on the sagittal alignment of femoral prosthesis and function recovery after total knee arthroplasty (TKA).
Between January 2007 and January 2009, 35 patients (35 knees) whose distal femoral flexion angle (DFFA) was more than 6 degrees underwent TKA. Reference to the method by Oswald for DFFA measurement, 35 patients were divided into 2 groups: group A (n = 23, 6 degrees < DFFA < 12 degrees, long intramedullary rod system) and group B (n = 12, DFFA > 12 degrees, short intramedullary rod system). Another random 30 osteoarthritis and 10 rheumatoid arthritis patients were selected as control group (group C, DFFA < 6 degrees). The postoperative femoral prosthesis flexion angle (FPFA), knee society score (KSS), the femoral notch, and extension dysfunction were analyzed.
All incisions healed by first intention. Seventy-five patients were followed up 1-3 years (mean, 2.1 years). The X-ray films showed that no signs of loosening, fracture, or infection were observed. There were significant differences in FPFA, the femoral notch, and knee extension dysfunction at 1 year after TKA between 3 groups (P < 0.05). The knee extension angle of group B was significantly larger than that of groups A and C (P < 0.05). There was no significant difference in the knee flexion angle and KSS score between 3 groups (P > 0.05). KSS score of postoperation was increased significantly when compared with preoperative values in 3 groups (P < 0.05).
Long intramedullary rod system in patients with higher DFFA usually leads to anterior femoral notch in TKA, so short intramedullary rods that can effectively avoid the notch should be selected in patients with DFFA > 12 degrees. But when the femoral prosthesis would be in flexion position, extension dysfunction usually occurs.
分析全膝关节置换术（TKA）后股骨远端屈曲角度（DFFA）对股骨假体矢状位对线及功能恢复的影响。
2007年1月至2009年1月，对35例（35膝）股骨远端屈曲角度大于6°的患者行TKA。参照Oswald测量DFFA的方法，将35例患者分为2组：A组（n = 23，6°＜DFFA＜12°，长髓内杆系统）和B组（n = 12，DFFA＞12°，短髓内杆系统）。另随机选取30例骨关节炎患者和10例类风湿关节炎患者作为对照组（C组，DFFA＜6°）。分析术后股骨假体屈曲角度（FPFA）、膝关节协会评分（KSS）、股骨切迹及伸直功能障碍情况。
所有切口均一期愈合。75例患者随访1 - 3年（平均2.1年）。X线片显示未观察到松动、骨折或感染迹象。3组患者TKA术后1年时FPFA、股骨切迹及膝关节伸直功能障碍方面差异有统计学意义（P＜0.05）。B组膝关节伸直角度显著大于A组和C组（P＜0.05）。3组膝关节屈曲角度及KSS评分差异无统计学意义（P＞0.05）。3组术后KSS评分较术前均显著提高（P＜0.05）。
DFFA较高的患者在TKA中使用长髓内杆系统通常会导致股骨前方切迹，因此对于DFFA＞12°的患者应选择能有效避免切迹的短髓内杆。但当股骨假体处于屈曲位时，通常会出现伸直功能障碍。
