Hamzeh Malaak, Gwynne Kaelyn, Panish Brian J, Gelfand Bradley, Argintar Evan
Orthopaedic Surgery, Georgetown University School of Medicine, Washington, DC, USA.
Orthopaedic Surgery, MedStar Georgetown University Hospital, Washington, DC, USA.
Cureus. 2024 Feb 28;16(2):e55173. doi: 10.7759/cureus.55173. eCollection 2024 Feb.
Introduction The goal of total knee arthroplasty is to replace diseased cartilage and bone with an artificial implant to improve the patient's quality of life. The knee has historically been reconstructed to the patient's mechanical axis (MA). However, kinematically aligned techniques have been increasingly used. Kinematic alignment requires less soft-tissue resection and aligns the knee with what is anatomically natural to the patient, while there is concern that kinematically aligned knees will lead to earlier failure due to potential unequal weight distribution on the implant. The purpose of this study is to compare the parallelism from the floor of the joint-line cuts using kinematic and mechanical alignment and understand if the MA is a proper estimation of the tibial-ankle axis (TA). Methods A retrospective study was conducted by recruiting all high tibial osteotomy and distal femoral osteotomy recipients operated on by two surgeons in two MedStar Health hospitals from 01/2013 to 07/2020 with full-length films in preparation for restorative procedures. Baseline osteoarthritis was graded using the Kellgren-Lawrence classification system with all patients presenting as Grade 0. The TA and the joint-line orientations of the MA and kinematic axis (KA) were measured on 66 legs. The average distance from parallelism to the ground was compared between the MA and the KA and between the MA and the TA using a paired t-test. Results KA joint-line orientation (1.705° deviation) was more parallel to the floor in the bipedal stance phase than the MA (2.316° deviation, p=0.0156). The MA (2.316° deviation) was not a proper estimation of the TA (4.278° deviation, p=0.0001). Conclusion By utilizing the KA technique, the restoration of the natural joint line, as well as a joint that is more parallel to the floor in the stance phase compared to the MA, is achieved. The parallelism to the ground of the KA during the bipedal stance phase suggests an even load distribution across the knee. In addition, due to its similarity to the KA and anatomical significance in weight-bearing distribution, further investigation into the hip-to-calcaneal axis as an approximation of the joint line is warranted.
引言 全膝关节置换术的目标是用人工植入物替换病变的软骨和骨骼，以提高患者的生活质量。膝关节在历史上一直是根据患者的机械轴（MA）进行重建的。然而，运动学对齐技术已越来越多地被使用。运动学对齐需要更少的软组织切除，并使膝关节与患者的解剖学自然状态对齐，同时有人担心运动学对齐的膝关节会因植入物上潜在的不均匀重量分布而导致更早失效。本研究的目的是比较使用运动学和机械对齐时关节线切口平面的平行度，并了解MA是否是胫-踝轴（TA）的恰当估计。方法 进行一项回顾性研究，招募了2013年1月至2020年7月期间在两家MedStar Health医院由两位外科医生进行手术的所有高位胫骨截骨术和股骨远端截骨术受术者，并准备了全长X线片以进行修复手术。使用Kellgren-Lawrence分类系统对基线骨关节炎进行分级，所有患者均表现为0级。在66条腿上测量TA以及MA和运动轴（KA）的关节线方向。使用配对t检验比较MA与KA之间以及MA与TA之间到地面平行度的平均距离。结果 在双足站立阶段，KA关节线方向（偏差1.705°）比MA（偏差2.316°，p = 0.0156）更平行于地面。MA（偏差2.316°）不是TA（偏差4.278°，p = 0.0001）的恰当估计。结论 通过采用KA技术，可以实现自然关节线的恢复，以及与MA相比在站立阶段更平行于地面的关节。双足站立阶段KA与地面的平行度表明膝关节上的负荷分布均匀。此外，由于其与KA的相似性以及在负重分布中的解剖学意义，有必要进一步研究髋-跟轴作为关节线近似值的情况。
