初次全膝关节表面置换术的学习曲线评估

Assessment of Learning Curve for Primary Total Knee Arthroplasty

目的评估早期初次全膝关节置换术的学习曲线,为将要开展TKA术或已开展未跨越早期学习曲线的术者提供经验。方法回顾分析本组早期手术治疗膝关节骨病53例(60膝),按手术先后分成6组,评估手术时间、出血量、术中并发症,术后影像学资料。结果本组平均手术时间(172.3±36.2)min,随病例量增加呈线性下降趋势(r=-0.713)。术后24 h出血量平均为(219.1±40.8)ml,最多组平均(316±108.9)ml,最少组平均(164.5±65.9)ml,两组比较差异有统计学意义(P<0.05)。术中2膝出现异常情况,均发生在前30膝(前3组)。KSS评分由术前平均(57.7±6.7)分提高到末次随访的(90.4±5.9)分。Kaplan-Meier假体生存率为96%。术后下肢力线、胫骨假体内外翻角及后倾角,前、后3组异常频率比9∶2、4∶0及7∶1,均有明显的统计学差异(P<0.05)。结论手术者具有普通骨科技能开展TKA完全可行,且术后疗效可,能顺利越过早期学习曲线。约完成30膝TKA后,手术技能趋向稳定形成渐近曲线。

Objective To assess the early learning curve for primary total knee arthroplasty （TKA） and provide relevant experiences for other surgeon teams who will perform this procedure and have been carrying out but not breaking this curve as well. Methods Fifty three cases with sixty consecutive primary total knee arthroplasty in which the components were placed by the same surgical group were reviewed retrospectively. The cohort cases were divided into 6 groups, 10 knees each, and evaluated clinical items which included surgical duration time, postoperative 24-hour blood loss, intra-operative severe complications, KSS scores, prosthetic survival rate, imaging result with post-operation X-ray. Results The average procedure duration time was （172.3±36.2）min, individual data points were connected by a straight line and a decline linear （best fit） trend line which the slope of the line was （-0.713）. The average postoperative 24-hour blood loss was （219.1±40.8）ml. The most group with （316±108.9）ml and the lowest group with （164.5±65.9）ml was statistically different （P 〈 0.05）. There were 2 cases with severe intra-operative complications presented in the former 30 cases. The pre-procedure KSS score was （57.7±6.7）points, which improved to （90.4±5.9）points at final follow-up. The Kaplan-Meier survival of components was 96%. In early stage the ratios of inccuracy limb alignment angle between the former three groups and the later was 9：2, tibia prosthesis with varus and valgus angle was 4：0, and those caster angle was 7：1, which were statistically different （P 〈0.05）. Conclusion The surgeon performing TKA is completely feasible with the base on the general orthopedic skills, and the surgical effects will be positive, who are supposed to cross the early stage TKA learning curve smoothly. Experiencing the same 30 examples, the team＇s TKA skills will be stable and form their own relevant curvilinear asymptote.