Objective: To explore the gait trajectory characteristics of patients after total knee arthroplasty (TKA) assisted by three-dimensional (3D) printing navigation template.
Methods: Twenty female patients (20 knees) with knee osteoarthritis who were treated with TKA assisted by 3D printing navigation template between February 2017 and February 2018 were selected as the 3D printing group. The patients were 50-69 years old, with an average age of 57.2 years. The disease duration was 4-7 years, with an average of 5.6 years. The osteoarthritis was classified as Kellgren-Lawrence Ⅲ level in 5 cases and Ⅳ level in 15 cases. The preoperative hip-knee-ankle angle (HKA) was (170.8±5.6)°. All patients were varus deformity. According to age and affected side, 20 healthy female volunteers were selected as the control group. The volunteers were 51-70 years old, with an average age of 56.7 years. Preoperative HKA was (178.8±0.6)°. There was significant difference in HKA between the two groups ( P>0.05). The HKA, Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and visual analogue scale (VAS) scores of the 3D printing group before and after operation were compared. At 6 months after operation, the gait trajectory characteristics of 3D printing group and control group were analyzed by Vicon gait capture system. The kinematics parameters included velocity, cadence, stride length, maximum knee flexion angle (stance), minimum knee flexion angle (stance), maximum knee flexion angle (swing), mean hip rotation angle (stance), mean ankle rotation angle (stance).
Results: The incisions of 3D printing group healed by first intention, with no complications. All patients were followed up 7-12 months (mean, 9.0 months). The WOMAC and VAS scores at 6 months after operation were significant lower than those before operation ( P<0.05). The HKA was (178.8±0.8)° at 4 weeks after operation and the difference was significant when compared with that before operation ( t=39.203, P=0.000). The position of the prosthesis was good. The femoral posterior condyle osteotomy line, surgical transepicondylar axis, and patella transverse line were parallel, varus deformity was corrected, and lower limb alignment was restored to neutral position. Gait analysis at 6 months after operation showed that the differences in all kinematics parameters between the two groups were significant ( P<0.05).
Conclusion: Assisted by 3D printing navigation template, TKA can alleviate pain symptoms and correct deformity, with satisfactory early effectiveness. Compared with healthy people, the early postoperative gait of the patients were characterized by decreasing velocity, cadence, stride length, knee flexion range, and increasing compensatory hip and ankle rotation range.
目的: 探讨 3D 打印导板辅助人工全膝关节置换术（total knee arthroplasty，TKA）后患者步态特点。.
方法: 选择 2017 年 2 月—2018 年 2 月接受 3D 打印导板辅助 TKA 治疗的 20 例（20 膝）膝关节骨关节炎女性患者为研究对象（手术组）。患者年龄 50～69 岁，平均 57.2 岁。病程 4～7 年，平均 5.6 年。骨关节炎分级：Kellgren-LawrenceⅢ级 5 例，Ⅳ级 15 例。术前髋-膝-踝角（hip-knee-ankle angle，HKA）为（170.8±5.6）°，内翻畸形。按照年龄及侧别进行配比，选择 20 名健康女性志愿者为对照组。年龄 51～70 岁，平均 56.7 岁；HKA 为（178.8±0.6）°。两组 HKA 比较差异有统计学意义（ t=6.352， P=0.000）。比较手术组手术前后 HKA、美国西部 Ontario 与 McMaster 大学骨关节炎指数评分（WOMAC）及疼痛视觉模拟评分（VAS）。术后 6 个月使用 Vicon 三维步态捕捉系统进行步态分析，比较手术组与对照组运动学参数，包括步速、步频、步长以及支撑相膝关节最大屈曲角度、支撑相膝关节最小屈曲角度、摆动相膝关节最大屈曲角度、支撑相平均髋关节旋转角度、支撑相平均踝关节旋转角度。.
结果: 手术组患者术后切口均Ⅰ期愈合，无手术相关并发症发生。患者均获随访，随访时间 7～12 个月，平均 9.0 个月。术后 6 个月 WOMAC 评分及 VAS 评分均优于术前（ P<0.05）。影像学复查示，术后 4 周 HKA 为（178.8±0.8）°，与术前比较差异有统计学意义（ t=39.203， P=0.000）；假体位置良好，股骨后髁截骨线、外科通髁线及髌骨横轴平行，内翻畸形均矫正，下肢力线恢复至中立位。术后 6 个月步态分析显示两组运动学参数比较，差异均有统计学意义（ P<0.05）。.
结论: 与健康人群相比，3D 打印导板辅助 TKA 术后早期患者步态主要表现为步速、步频及步长减小，膝关节屈曲范围减小，代偿性髋关节及踝关节旋转范围增大的特点。.
Keywords: Three-dimensional printing technology; gait analysis; kinematics; navigation template; total knee athroplasty.