性别对全膝关节置换术中股骨假体匹配及术后早期功能的影响

Gender differences in femoral component fit and clinical outcomes with unisex total knee prosthesis

目的探讨性别对全膝关节置换术中截骨后股骨假体匹配及术后早期功能的影响。方法2012年12月至2014年12月接受单侧全膝关节置换的膝关节骨关节炎患者120例122膝，采用股骨假体前后径阶差为2 mm的Vanguard髁间开放式高屈曲后稳定型假体。比较男性与女性患者术中测量的截骨后股骨远端纵横比（distal femoral aspect ratio，DFAR）、股骨假体悬突或骨质覆盖不全程度，比较术后2年两组膝关节协会评分Knee Society Score，KSS）、西安大略和麦克马斯特大学（Western Ontario and McMaster Universities，WOMAC）骨关节炎指数、起立行走时间试验、起立试验、登梯时间、屈膝度、伸膝迟滞、屈曲挛缩、自拟膝前痛评分及患者满意度的差异。结果107例109膝纳入分析，男33例33膝，女74例76膝。男性组股骨远端2区的总悬突值[（-5．51±4．46）mm]和3区的总悬突值[（-5．99±4．73）mm]均小于女性组[分别为（-3．24±3．93）mm和（-3．45±3．98）mm]。男性组的骨质覆盖不全更明显，3区的显著覆盖不全率高于女性（60．6％、23．7％）。男性前后髁均完成截骨后的DFAR1（1．56±0．12）、仅前髁截骨完成后的DFAR2（1．28±0．08）均显著大于女性（1．51±0．12、1．24±0．11）。与术中假体植入后的屈膝度相比，男性术后2年的屈髋900位抗重力自然屈膝度改变值（-8．73°±7．71°）及被动屈膝度改变值（-11．45°±8．78°）均小于女性组（-4．82°±6．67°、-7．34°±8．71°）。男性组术中关节囊缝合后的自然屈膝度（132．85°±6．01°）大于女性组（128．78。±6．34。），但被动屈膝度的差异无统计学意义。男性组术后2年非负重位被动屈膝度改变值（1．67°±14．76°）小于女性组（7．64°±12．40°），KSS爬楼评分[（45．15±7．12）分]高于女性组[（40．13±7．74）分]，能够自行完成蹲起动作的比例（97．0％）高于女性组（81．6％）。结论截骨后DFAR存在显著的性别差异，但对全膝关节置换术后2年的临床疗效无明显影响。女性似乎有获得更大屈膝度的潜能，男性骨质覆盖不全的发生率更高。

Objective To determine the effects＇of gender on distal femoral aspect ratio （DFAR）, femoral component fit, and clinical outcmnes at 2 years after total knee arthroplasty （TKA）. Methods From December 2012 to December 2014, the clinical and radiographic characteristics of 107 consecutive patients （109 knees） were studied prospectively. All patients were divided into two groups according to gender： 33 cases （33 knees） were male and 74 cases （76 knees） were female. These subjectives underwent unilateral primary TKAs for end-stage osteoarthritis by using Vanguard high-flex open-box posterior-stabilized fixed-bearing prosthesis. The anterior-posterior size increment of the Vanguard femoral components was 2 mm. The clinical outcomes （Knee Society Score, Western Ontario and McMasters University osteoarthritis index, time-up-to-go test, chair rise test, stair-climbing test, range of flexion, extensor lag, flexion contracture, anterior knee pain score and patient satisfaction） between two groups were compared at 2 years postoperatively. The femoral component fit and two kinds of DFARs were also compared intraoperatively. Results The total overhang value in zone 2 was -5.51±4.46 mm in male and -3.24±3.93 mm in female, respectively. That in zone 3 was -5.99±4.73 mm in male and -3.45±3.98 mm in female. The total underhang value in male was significantly higher than that in female （P〈0.05）. The rate of significant underhang in zone 3 was significantly higher in male than that in female （60.6%, 23.7%, P〈0.05）. Two kinds of DFARs in male were significantly higher than those in female （1.56±0.12 vs. 1.51 ±0.12, 1.28±0.08 vs. 1.24±0.11, P〈0.05）. Compared with intra-operative range of flexion （ROF） in the condition of 90± hip flexion after prosthesis implantation, the loss of ROF against gravity and the loss of passive ROF at 2 years postoperatively were statistically significant higher than those in female （-8.73°±7.71° vs. -4.82°±6.67°, -11.45°±8.78° vs. -7.34°±8.71°, P〈0.05）. In the male group, the natural ROF after capsule closed （132.85°±6.01°） was significantly larger than that of the female group （128.78°±6.34°）, but there was no significant difference in passive flexion. The change of non-weight-hearing passive ROF （1.67°± 14.76°）, the Knee Society stair- climbing score （45.15±7.12） and the proportion of being able to squat and rise （97.0%） in male group were greater than those in female group, postoperatively. Conclusion Although DFAR is different within gender; it has little effects on early outcomes after unisex posterior-stabilized TKA. The loss of ROF in male is more prominent than that in female. Increased size offerings of femoral components improve fit in female distal femur. However, distal femur of male still exist obvious underhang.