Li Mengyuan, Zhang Lei, Zhang Ruiying, Ma Yuanchen, Liao Junxing, Li Qingtian, Deng Zhantao, Zheng Qiujian
Division of Joint Osteopathy and Traumatology, Center of Orthopedics Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 106, Zhongshaner Road, Yuexiu District, Guangzhou, People's Republic of China.
Division of Rehabilitation, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, People's Republic of China.
Arthroplasty. 2020 Feb 7;2(1):5. doi: 10.1186/s42836-020-0022-4.
Strength deficits, muscle imbalances, and quadriceps inhibition are common after the total knee arthroplasty (TKA). It was suggested that theoretically single radius (SR) femoral protheses could provide longer extensor moment arm compared to the multiple radius (MR) design. However, quantitative evidence has not yet been reported. Thus, the aim of the study was to investigate the differences in isokinetic data and to compare the patient-reported outcome scores between TKA SR and MR design.
The present retrospective study included 36 TKA involving 16 knees (9 patients) using SR design implant and 20 knees (11 patients) using MR design implant. The mean follow-up time was longer than 1 year. Isokinetic knee flexion and extension torques of the operated leg were evaluated at 60°/s and 180°/s. Quadriceps and hamstring torques and ratios, work and power were recorded. Angle-specific torques were also collected at different extension or flexion angles.
Both groups showed improvement in knee society scores (KSS) and knee injury, and osteoarthritis outcome score (KOOS) after operation. Patients in SR group had significantly higher scores in KSS-knee, symptoms and activities of daily living KOOS sub-score than those in the MR group at the end of the follow-up. The peak knee flexion torque, peak knee extension torque and maximum knee flexion work were greater in SR group at 180°/s and 60°/s. At 60°/s, and SR group had higher average knee flexion power and average knee extension power than MR group. In the isometric contraction test, the knee extension torque was higher in SR group than in MR group. At 180°/s, SR group showed higher flexion torques at 30°, 40°, 50°, 60° compared with MR group. At 60°/s, SR group showed higher flexion torques at 30°, 40°, 50°, 60°, 80° when compared with MR group. Additionally, SR group also provided higher extension torques at 40°, 50°, 60° than the MR group. There were no differences in other isokinetic and isometric parameters between the two groups.
Femoral design exerted an influence on quadriceps and hamstring strength after TKA, and SR design shows advantages, in terms of higher extension and flexion strength, over MR design.
全膝关节置换术（TKA）后常见力量不足、肌肉失衡和股四头肌抑制。理论上有人认为，与多半径（MR）设计相比，单半径（SR）股骨假体可提供更长的伸肌力矩臂。然而，尚未有定量证据报道。因此，本研究的目的是调查等速数据的差异，并比较TKA中SR和MR设计患者报告的结局评分。
本回顾性研究纳入了36例TKA患者，其中16膝（9例患者）使用SR设计植入物，20膝（11例患者）使用MR设计植入物。平均随访时间超过1年。以60°/秒和180°/秒的速度评估患侧膝关节的等速屈伸扭矩。记录股四头肌和腘绳肌的扭矩及比值、功和功率。还收集了不同伸展或屈曲角度下特定角度的扭矩。
两组患者术后膝关节协会评分（KSS）以及膝关节损伤和骨关节炎结局评分（KOOS）均有所改善。随访结束时，SR组患者在KSS-膝关节、症状和日常生活活动KOOS子评分方面显著高于MR组。在180°/秒和60°/秒时，SR组的膝关节最大屈曲扭矩、最大伸展扭矩和最大屈曲功更大。在60°/秒时，SR组的平均膝关节屈曲功率和平均膝关节伸展功率高于MR组。在等长收缩试验中，SR组的膝关节伸展扭矩高于MR组。在180°/秒时，与MR组相比，SR组在30°、40°、50°、60°时显示出更高的屈曲扭矩。在60°/秒时，与MR组相比，SR组在30°、40°、50°、60°、80°时显示出更高的屈曲扭矩。此外，SR组在40°、50°、60°时的伸展扭矩也高于MR组。两组之间的其他等速和等长参数没有差异。
股骨设计对TKA术后股四头肌和腘绳肌力量有影响，SR设计在伸展和屈曲强度方面比MR设计具有优势。
