解析型内侧膝关节单髁置换术:手术流程及早期临床实践

Analytical medial unicondylar knee arthroplasty:surgical procedure and early clinical practice

目的报道解析型内侧膝关节单髁置换(unicompartmental knee arthroplasty,UKA)手术流程及影像学结果,并以UKA术中关节间隙变化为主要指标,探究解析型UKA对手术规划和假体设计的指导作用。方法研究纳入2022年5月至2024年4月间开展的机器人辅助解析型内侧UKA手术患者,报道解析型UKA手术基本流程及达到动态间隙平衡的患者比例,分类解析动态间隙平衡曲线形态模式,并对比纳入患者术前及术后髋膝踝(hip-knee-ankle,HKA)角,股骨后髁偏心比(posterior condylar offset ratio,PCOR)及胫骨后倾(posterior tibial slope,PTS)。结果本研究共纳入18例解析型内侧UKA手术患者,9例(50.0%)达到动态间隙平衡。动态间隙曲线主要呈现为U型(44.4%)、倒U型(33.3%)和水平型(11.1%)。其中13例患者获得间隙平衡求解曲线,在股骨髁未截骨状态下,间隙平衡求解曲线显示屈膝10°~50°范围内关节撑开间隙均明显大于屈膝70°~120°。试模植入后,4例(30.8%)间隙平衡求解曲线达到直线型,7例(53.8%)表现为屈膝70°及以上,关节间隙随着屈膝角度增大而增大。本组患者术后HKA角度(178.67°±3.09°)较术前(173.00°±2.88°)明显改善(P<0.001)。术后与术前PCOR平均值差异无统计学意义(0.51±0.05 vs 0.52±0.03,P=0.518),但术后PTS值(7.75°±3.28°)显著小于术前PTS(10.66°±3.03°)(P=0.001)。结论解析型内侧UKA通过对术中多重参数的实时量化解析,可指导手术方案决策,术后影像学力线满意,部分患者可实现整个屈伸过程中动态间隙平衡。

Objective To report the surgical procedure,early radiographic outcomes and real-time change of joint space balance in analytical medial unicompartmental knee arthroplasty(UKA),and to explore the utilization of analytical UKA in surgical planning and implant design.Methods This study included the robotic analytical UKA performed in our institute between May 2022 and April 2024.The procedures of analytical UKA were reported in detail.The percentage of patients who reached the dynamic joint space balance were calculated,and the curves of dynamic joint space balance were classified according to their patterns.Preoperative and postoperative hip-knee-ankle(HKA)angle,posterior condylar offset ratio(PCOR)and posterior tibial slope(PTS)were compared.Results Eighteen analytical medial UKA cases were included and 9 UKAs(50.0%)reached the dynamic joint space balance.The main types of these curves were U type(44.4%),inverted U type(33.3%)and horizontal type(11.1%).The knee balance solver was used in 13 cases.The curves of the knee balance solver system indicated that before the femoral cutting the gaps at flexion 10°-50°were larger than those at flexion 70°-120°in all cases.After the trial implantation,the knee balance solver curve in four cases(30.8%)changed into linear type while seven cases(53.8%)showed that after 70°the gaps would increase when the knees were at a higher knee flexion angle.Postoperative HKA were improved when compared with preoperative HKA(178.67°±3.09°vs 173.00°±2.88°;P<0.001).There was no significant difference between the preoperative and postoperative PCOR(0.51±0.05 vs 0.52±0.03,P=0.518),while the mean postoperative PTS were significantly smaller than the mean preoperative PTS(7.75°±3.28°vs 10.66°±3.03°,P=0.001).Conclusions Analytical medial unicompartmental knee arthroplasty can guide the surgical planning through the real-time quantitative analysis of multiple parameters.The postoperative radiographic parameters are satisfactory.Some patients can achieve dynamic gap balance during the whole process of flexion and extension.