不同类型的膝关节假体对站立时静态稳定性的影响研究

The Influence of Fixed-bearing and Rotating-platform Total Knee Arthroplasty on Static Body Balance in knee osteoarthritis

目的探讨人工全膝关节置换术(total knee arthroplasty,TKA)中选用固定平台(fixed-bearing)型(PFC-sigma)和旋转平台(rotating-platform)型(PFC-RP)膝关节假体对膝关节骨关节炎(knee osteoarthritis,OA)患者术后躯体静态稳定性产生的影响。方法对2011年1月至2013年12月在我院接受单侧TKA的OA患者45例(选用旋转平台型假体PFC-RP的患者21例,选用固定平台型假体PFC-Sigma的患者24例)进行分析。术前、术后6个月和术后1年时采用HSS评分标准对术侧膝关节进行功能评估,并用重心测量仪对患者进行站立平衡试验,连续记录躯体重心位置(gravity center position,GCP)。对GCP在水平方向上转移程度(medio-lateral displacement,ML-X range)以及GCP漂移轨迹(locus of GCP,LG)进行量化并分析两组患者之间的静态稳定性、术侧膝关节恢复情况以及术后并发症发生率的差异性。结果 TKA后单位时间内GCP在水平方向上平均位置由初始位置逐渐向术侧转移,且两组患者之间MLX range上变化程度差异均无统计学意义(P>0.05),而选用PFC-RP型假体的患者LG水平明显较选用PFC-Sigma的患者小,且差异性有统计学意义(P<0.05)。结论两组患者术后术侧膝关节恢复情况、并发症发生率无明显差异性,而选PFC-RP型假体的患者较PFC-Sigma的患者具有更好的静态时稳定性。

Objective To compare the static body balance between fixed - beating total knee arthroplasty （PFC-Sigma） and rotating-platform total knee arthroplasty（PFC-RP） in patients＇ who suffered from unilateral knee osteoarthritis. Methods Forty-five patients with single osteoarthtitis of tight knee who underwent TKA at our department from January 2011 to December 2013 were prospectively analyzed. 21consecutive patients were replaced with rotating-platform total knee design （PFC-RP） and the others with fixed-beating design （PFC-Sigma）. The measurements were performed using the corresponding instrument and subjects completed consecutive double-limb standing balance trials for three times. The Medio-lateral displacements and Locus Length of GCP （LG） in unit-time were derived from the instrument. All the patients were evaluated with HSS and com- plete balance trails pre-operatively, sixth month and one year postoperatively. Clinical outcome complication rates and body static balance were compared. Results The mean GCP in the medio-lateral direction shifted to the operative side in both groups after surgery, there was no significant difference in ML-Xrange between the groups （ P 〉 0.05 ）. The value of Locus of GCP（LG） was smaller in PFC-RP group than PFC-Sigma group（ P 〈 0. 05 ）. Conclusion Our study demonstrated no advantage of the rotating-platform arthroplasty over fixed-bearing arthroplasty with regard to clinical results and complication rates at one year follow-up. However, rotating-platform arthroplasty has a better body static balance than fixed-beating arthroplasty.