全膝股骨假体矢状面位置与术后膝前痛及功能的关系

Correlations in sagittal position of femoral componenet of knee arthroplasty and postoperative patellofemoral pain and joint function

目的本研究旨在回顾性研究股骨矢状面位置与人工全膝关节置换术后膝前痛及关节功能的相关性。方法本研究纳入广州医科大学附属第六医院保守治疗无效的终末期膝骨关节炎接受人工全膝关节表面置换的患者99例(共99膝),排除感染性、炎症性关节炎及合并脊柱、髋或踝关节病变患者,随访时间节点为术后1年。本研究分别采用患者报告结局(PROMs)包括美国膝关节协会评分(KSS),西大略和麦克马斯特大学骨关节炎指数评分(WOMAC),膝关节置换术后遗忘评分(FKS)及患者满意度评分,医师报告临床结局(CROMs),包括膝关节活动度(ROM)、股骨前髁偏心距及股骨远端前皮质线与股骨假体纵轴线的夹角(α角)。根据α角分为股骨假体屈曲组(α角>0°)及股骨假体过伸组(α角<0°),并利用t检验及一元二次方程分别统计分析α角与PROMs及CROMs的相关性。结果股骨假体屈曲组的术后PROMs优于股骨假体过伸组(KSS关节评分t=2.764、功能评分t=2.215、FKS t=4.012、满意度t=2.492,均为P<0.05),而假体屈曲组患者术后膝前痛的发生率10.0%明显低于假体过伸组28.6%(χ^(2)=5.504,P=0.019),一元二次方程分析显示α角与术后股骨前髁偏心距比值(ACO)存在凸面向上的弧形相关性,其中顶点的α角为2.411°,相应的ACO比值为20.5%(P=0.006)。结论相对于股骨假体过伸的患者,股骨假体屈曲的患者术后膝前痛发生率较低,且术后关节功能恢复较好,可能与术后股骨前髁偏心距降低从而对股骨假体矢状面位置影响较小有关。

Objective To retrospectively analyse the correlations between sagittal position of the femoral prothesis and patellofemoral pain as well as joint function after total knee arthroplasty(TKA).Methods A total of 99 patients with end-stage knee osteoarthritis who failed to respond to conservative treatment and underwent total knee arthroplasty in the Sixth Affiliated Hospital of Guangzhou Medical University were enrolled.Patients with infectious,inflammatory arthritis and spinal,hip or ankle joint lesions were excluded,and the follow-up time was one year after surgery.In this study,patient-reported outcome measures(PROMs)included Knee Society score(KSS),the Western Ontario and McMaster(WOMAC),forgotten knee score(FKS)and patient satisfaction scores,clinician-reported outcome measures(CROMs),including range of motion(ROM),anterior condylar offset(ACO)and the angle between the flange of the femoral component(FC)and the distal femur anterior cortex line(αangle).According to theαangle,the patients were divided into two groups,the FC flexion group(αangle>0°)and the FC extension group(αangle<0°).The correlations between PROMs and CROMS were analyzed by t test and secondary regression.Results Postoperative PROMs in the FC flexion group were better than those in the FC extension group(KSS joint score t=2.764,functional score t=2.215,FKS t=4.012,satisfaction scores t=2.492,P<0.05),while the incidence of postoperative anterior knee pain in the FC flexion group(10.0%)was significantly lower than that in the FC extension group(28.6%)(χ^(2)=5.504,P=0.019),secondary regression analysis indicated that there was a convex upward correlation between theαangle and the postoperative ACO ratio.Theαangle at the vertex was 2.411°,corresponding to the ACO ratio was 20.5%(P=0.006).Conclusion Compared with patients with FC extension,patients with FC flexion have a lower incidence of anterior knee pain and better recovery of joint function,which may be associated with the reduction of postoperative ACO having less effect on the sagittal plane position of FC.