Innex膝关节假体置换术后活动度与假体设计及手术技术的关系

The influence of component design and related surgical technique on knee range of motion after total knee replacement using Innex knee system

目的 探讨Innex膝关节假体置换术后膝关节活动度与假体设计及手术技术的关系.方法 2003年9月至2005年12月使用CS型Innex假体行全膝关节置换88例（98膝）,均患膝关节骨关节炎,体重指数20～30 kg/m2,内外翻畸形、屈曲畸形＜15°,为初次全膝关节置换并使用相同的手术技术.随访63例（70膝）,随访时间4～6年,平均5.3年.分析活动度与股骨后髁偏心距和胫骨平台后倾角的相关性.根据术后、术前股骨后髁偏心距的差值大小将患者分为：1组,＜-2 mm;2组,-2～0 mm;3组,0～2 mm,4组,＞2 mm.分析各组术前体重指数、屈曲畸形、活动度、特种外科医院膝关节评分及术后活动度的差异.结果 随访患者术前膝关节活动度平均96.2°±11.9°,末次随访时平均109.8°±13.0°;术前股骨后髁偏心距平均（24.0±3.5）mm,术后平均（24.5±3.3）mm;术后胫骨平台后倾角平均5.5°±1.8°.膝关节活动度的差值与股骨后髁偏心距的差值相关,术后膝关节活动度与术后胫骨平台后倾角不相关.四组患者术前体重指数、屈曲畸形、活动度、特种外科医院膝关节评分差异无统计学意义,而术后活动度的差异有统计学意义.结论 Innex膝关节假体置换术后膝关节活动度良好.术中行股骨后方截骨时需注意恢复股骨后髁偏心距,以增加术后活动度.术后膝关节活动度与胫骨平台后倾角无关.

Objective To analysis the influence of component design and related surgical technique on knee range of motion （ROM） after total knee replacement using Innex knee system. Methods Between September 2003 and December 2005, 88 patients with 98 knees had consecutively undergone posterior cruciate-sacrificing TKA with Innex systems. The posterior condylar offset, post-operative tibial slope and knee ROM were measured in 63 patients （70 knees）. The relationship of the change in posterior condylar offset and postoperative tibial slope with knee ROM was assessed using a scatterplot graph and Pearson＇s regression analysis. According to change of posterior condylar offset, which was measured by postoperative minus preoperative posterior condylar offset, patients were divided into 4 groups. The preoperative body mass index,flexion contracture, knee ROM, HSS score and the postoperative knee ROM of four groups were evaluated.Results The mean knee ROM had improved from 96.2°±11.9° preoperative to 109.8°±13.0° at final followup. The mean pre- and post-operative posterior condylar offset was （24.0±3.5） mm and （24.5±3.3） mm, respectively. The mean postoperative tibial slope was 5.5°±1.8°. There was statistical correlation between the difference in the posterior condylar offset and the change in knee ROM after TKA and no correlation between the postoperative tibial slope and knee ROM postoperatively. The preoperative body mass index, flexion contracture, knee ROM, HSS score did not show difference among four groups. There was a statistically difference in postoperative knee ROM among groups. Conclusion Restoration of posterior condylar offset is important to the maximum range of postoperative knee ROM when Orthopedic surgeons perform TKA with Innex systems.There was no correlation between the postoperative tibial slope and postoperative ROM.