An unusual case of early dislocation of a mobile bearing posterior stabilized total knee arthroplasty in a 48-year-old Caucasian woman is described. Dislocation occurred one day postoperatively, attributed to a gap mi...An unusual case of early dislocation of a mobile bearing posterior stabilized total knee arthroplasty in a 48-year-old Caucasian woman is described. Dislocation occurred one day postoperatively, attributed to a gap mismatch. Revision surgery reduced posterior dislocation, increased bearing plate thickness and rebalanced ligaments. A second dislocation occurred after revision surgery. The patient’s history was retaken and a hamstring spasm disease identified. A new revision utilized a more constrained design, without perioperative local nerve block. Two years following surgery, no further dislocation had occurred. A numerical musculoskeletal model of the case and implant configuration identified no trend to mobile bearing dislocation when regular muscle forces were applied. Muscle spasm is a risk factor for mobile bearing total knee arthroplasty dislocation, especially with femoral nerve block.展开更多
Background: Controversies about the rational positioning of the tibial component in unicompartmental knee arthroplasty (UKA) still exist. Previous finite element (FE) studies were rare, and the results varied. Th...Background: Controversies about the rational positioning of the tibial component in unicompartmental knee arthroplasty (UKA) still exist. Previous finite element (FE) studies were rare, and the results varied. This FE study aimed to analyze the influence of the tibial component coronal alignment on knee biomechanics in mobile-bearing UKA and find a ration range of inclination angles. Methods: A three-dimensional FE model of the intact knee was constructed from image data of one normal subject. A 1000 N compressive load was applied to the intact knee model for validating. Then a set of eleven UKA FE models was developed with the coronal inclination angles of the tibial tray ranging from 10° valgus to 10° varus. Tibial bone stresses and strains, contact pressures and load distribution in all UKA models were calculated and analyzed under the unified loading and boundary conditions. Results: Load distribution, contact pressures, and contact areas in intact knee model were validated. In UKA models, von Mises stress and compressive strain at proximal medial cortical bone increased significantly as the tibial tray was in valgus inclination 〉4°, which may increase the risk of residual pain. Compressive strains at tibial keel slot were above the high threshold with varus inclination 〉4°, which may result in greater risk of component migration. Tibial bone resection comer acted as a strain-raiser regardless of the inclination angles. Compressive strains at the resected surface slightly changed with the varying inclinations and were not supposed to induce bone resorption and component loosening. Contact pressures and load percentage in lateral compartment increased with the more varus inclination, which may lead to osteoarthritis progression. Conclusions: Static knee biomechanics after UKA can be greatly affected by tibial component coronal alignment. A rauge from 4° valgus to 4° varus inclination oftibial component can be recommended in mobile-bearing UKA.展开更多
目的观察活动平台与固定平台单髁置换术对膝骨性关节炎手术治疗的短期疗效。方法选取内侧单间室膝骨关节炎患者155例,均行人工单髁置换术,其中97例选择美国邦美Oxford第三代活动平台(mobilebearing,MB)单髁假体,58例选择德国LINK固定平...目的观察活动平台与固定平台单髁置换术对膝骨性关节炎手术治疗的短期疗效。方法选取内侧单间室膝骨关节炎患者155例,均行人工单髁置换术,其中97例选择美国邦美Oxford第三代活动平台(mobilebearing,MB)单髁假体,58例选择德国LINK固定平台(fixed-bearing,FB)单髁假体。比较两组手术时间及术中出血量;术前及术后1周、1个月视觉模拟评分(VAS);术前及术后1个月、3个月、6个月膝关节活动度(range of motion,ROM)及美国特种外科医院(hospital for special surgery,HSS)评分,并进行统计学分析。结果MB组与FB组手术时间及术中出血量比较差异均无统计学意义(P均>0.05)。术前、术后1周及术后1个月VAS评分差异均无统计学意义(P均>0.05),术前及术后1个月、3个月、6个月两组间ROM、HSS评分及术后6个月内并发症发病率差异均无统计学意义(P均>0.05)。结论MB和FB单髁置换术在膝骨性关节炎中短期疗效差异无统计学意义,MB单髁假体术后易出现假体脱位。展开更多
目的:分析使用Oxford膝关节单间室假体置换术后出现内翻的术前影响因素。方法:选择北京积水潭医院矫形骨科2018年1月至2019年12月施行的660例(767膝)Oxford单间室置换患者的病例资料进行回顾性分析。根据术后力线X线片分为内翻组(Noyes...目的:分析使用Oxford膝关节单间室假体置换术后出现内翻的术前影响因素。方法:选择北京积水潭医院矫形骨科2018年1月至2019年12月施行的660例(767膝)Oxford单间室置换患者的病例资料进行回顾性分析。根据术后力线X线片分为内翻组(Noyes≥3°)和正常组(Noyes<3°)两组。比较两组患者性别、年龄、体重指数(body mass index,BMI)、膝关节活动度(range of motion,ROM)、术前屈曲畸形(flexion deformity,FD)、膝关节疼痛评分(American Knee Society pain score,AKS)和功能评分(American Knee Society function score,AKS function),测量术前Noyes角、股骨远端外侧角(lateral distal femoral angle,LDFA)、胫骨近端内侧角(medial proximal tibial angle,MPTA)、关节线相交角(joint line converge angle,JLCA),并对以上术前因素进行分析。结果:患者的性别、术侧、年龄、BMI、术前ROM、术前膝关节疼痛评分和功能评分不是术后力线内翻的危险因素(P>0.05)。术后内翻的影响因素依次为MPTA<84°(P=0.018,OR=3.712,95%CI:1.250~11.027),术前Noyes>5°(P=0.000,OR=3.105,95%CI:1.835~5.254),术前FD>5°(P=0.001,OR=1.976,95%CI:1.326~3.234)。术前LDFA(P=0.146)和术前JLCA(P=0.709)对术后力线都没有表现出统计学意义的影响。结论:术前内翻较重的患者,尤其内翻畸形主要来自胫骨侧的患者,以及术前有屈曲畸形的患者更容易出现Oxford单间室置换术后力线内翻。展开更多
文摘An unusual case of early dislocation of a mobile bearing posterior stabilized total knee arthroplasty in a 48-year-old Caucasian woman is described. Dislocation occurred one day postoperatively, attributed to a gap mismatch. Revision surgery reduced posterior dislocation, increased bearing plate thickness and rebalanced ligaments. A second dislocation occurred after revision surgery. The patient’s history was retaken and a hamstring spasm disease identified. A new revision utilized a more constrained design, without perioperative local nerve block. Two years following surgery, no further dislocation had occurred. A numerical musculoskeletal model of the case and implant configuration identified no trend to mobile bearing dislocation when regular muscle forces were applied. Muscle spasm is a risk factor for mobile bearing total knee arthroplasty dislocation, especially with femoral nerve block.
基金This work was funded by a grant from National Natural Science Foundation of China (No. 81273972).
文摘Background: Controversies about the rational positioning of the tibial component in unicompartmental knee arthroplasty (UKA) still exist. Previous finite element (FE) studies were rare, and the results varied. This FE study aimed to analyze the influence of the tibial component coronal alignment on knee biomechanics in mobile-bearing UKA and find a ration range of inclination angles. Methods: A three-dimensional FE model of the intact knee was constructed from image data of one normal subject. A 1000 N compressive load was applied to the intact knee model for validating. Then a set of eleven UKA FE models was developed with the coronal inclination angles of the tibial tray ranging from 10° valgus to 10° varus. Tibial bone stresses and strains, contact pressures and load distribution in all UKA models were calculated and analyzed under the unified loading and boundary conditions. Results: Load distribution, contact pressures, and contact areas in intact knee model were validated. In UKA models, von Mises stress and compressive strain at proximal medial cortical bone increased significantly as the tibial tray was in valgus inclination 〉4°, which may increase the risk of residual pain. Compressive strains at tibial keel slot were above the high threshold with varus inclination 〉4°, which may result in greater risk of component migration. Tibial bone resection comer acted as a strain-raiser regardless of the inclination angles. Compressive strains at the resected surface slightly changed with the varying inclinations and were not supposed to induce bone resorption and component loosening. Contact pressures and load percentage in lateral compartment increased with the more varus inclination, which may lead to osteoarthritis progression. Conclusions: Static knee biomechanics after UKA can be greatly affected by tibial component coronal alignment. A rauge from 4° valgus to 4° varus inclination oftibial component can be recommended in mobile-bearing UKA.
文摘目的观察活动平台与固定平台单髁置换术对膝骨性关节炎手术治疗的短期疗效。方法选取内侧单间室膝骨关节炎患者155例,均行人工单髁置换术,其中97例选择美国邦美Oxford第三代活动平台(mobilebearing,MB)单髁假体,58例选择德国LINK固定平台(fixed-bearing,FB)单髁假体。比较两组手术时间及术中出血量;术前及术后1周、1个月视觉模拟评分(VAS);术前及术后1个月、3个月、6个月膝关节活动度(range of motion,ROM)及美国特种外科医院(hospital for special surgery,HSS)评分,并进行统计学分析。结果MB组与FB组手术时间及术中出血量比较差异均无统计学意义(P均>0.05)。术前、术后1周及术后1个月VAS评分差异均无统计学意义(P均>0.05),术前及术后1个月、3个月、6个月两组间ROM、HSS评分及术后6个月内并发症发病率差异均无统计学意义(P均>0.05)。结论MB和FB单髁置换术在膝骨性关节炎中短期疗效差异无统计学意义,MB单髁假体术后易出现假体脱位。
文摘目的:分析使用Oxford膝关节单间室假体置换术后出现内翻的术前影响因素。方法:选择北京积水潭医院矫形骨科2018年1月至2019年12月施行的660例(767膝)Oxford单间室置换患者的病例资料进行回顾性分析。根据术后力线X线片分为内翻组(Noyes≥3°)和正常组(Noyes<3°)两组。比较两组患者性别、年龄、体重指数(body mass index,BMI)、膝关节活动度(range of motion,ROM)、术前屈曲畸形(flexion deformity,FD)、膝关节疼痛评分(American Knee Society pain score,AKS)和功能评分(American Knee Society function score,AKS function),测量术前Noyes角、股骨远端外侧角(lateral distal femoral angle,LDFA)、胫骨近端内侧角(medial proximal tibial angle,MPTA)、关节线相交角(joint line converge angle,JLCA),并对以上术前因素进行分析。结果:患者的性别、术侧、年龄、BMI、术前ROM、术前膝关节疼痛评分和功能评分不是术后力线内翻的危险因素(P>0.05)。术后内翻的影响因素依次为MPTA<84°(P=0.018,OR=3.712,95%CI:1.250~11.027),术前Noyes>5°(P=0.000,OR=3.105,95%CI:1.835~5.254),术前FD>5°(P=0.001,OR=1.976,95%CI:1.326~3.234)。术前LDFA(P=0.146)和术前JLCA(P=0.709)对术后力线都没有表现出统计学意义的影响。结论:术前内翻较重的患者,尤其内翻畸形主要来自胫骨侧的患者,以及术前有屈曲畸形的患者更容易出现Oxford单间室置换术后力线内翻。
文摘目的观察活动与固定平台的单髁假体置换(unicompartmental knee arthroplasty,UKA)在膝关节单间室骨关节炎中的临床应用效果。方法选择2018年1月至2019年1月收治的84例膝关节前内侧骨关节炎患者,随机分为对照组与观察组各42例。对照组采用Link固定平台UKA治疗,男20例,女22例;年龄52~88岁,平均(68.16±5.28)岁;左膝13例,右膝29例;身体质量指数(23.51±3.82)kg/m^(2);术前关节平均屈曲角度(115.62±5.49)°。观察组采用Oxford活动平台UKA治疗,男23例,女19例;年龄48~89岁,平均(68.37±5.43)岁;左膝14例,右膝28例;身体质量指数(23.54±3.75)kg/m^(2);术前关节平均屈曲角度(115.58±5.37)°。观察并记录膝关节功能、疼痛、关节活动度、并发症发生情况。结果两组患者术后24个月美国膝关节协会评分(knee society score,KSS)、美国特种外科医院(hospital for special surgery,HSS)膝关节评分均高于术前(P<0.05)。两组术后24个月HSS评分、KSS评分比较差异无统计学意义(P>0.05)。两组术后疼痛视觉模拟评分(visual analogue scale/score,VAS)均低于本组术前(P<0.05),组间比较差异无统计学意义(P>0.05)。两组术后胫股角(femoral tibia angle,FTA)、胫骨平台后倾角(sagittal tibial Angle,STA)较本组术前显著缩小(P<0.05)。术后关节最大屈曲角度、关节最大伸直角度明显优于术前(P<0.05),组间比较差异有统计学意义(P<0.05)。两组术后感染、假体松动、衬垫脱位、关节出血及纤维化、关节炎进展等并发症发生率比较差异无统计学意义(P>0.05)。结论活动平台与固定平台UKA治疗膝关节内单间室骨关节炎均可改善患者膝关节功能,减轻疼痛程度,改善关节活动度,不良反应发生率低。