Valderrabano Victor, Hintermann Beat, Nigg Benno M, Stefanyshyn Darren, Stergiou Pro
University of Basel, Clinic of Orthopaedic Surgery, Kantonsspital, Basel, Switzerland.
Foot Ankle Int. 2003 Dec;24(12):881-7. doi: 10.1177/107110070302401202.
The purpose of this study was to determine how closely the present designs of ankle prostheses mimic the unique requirements of the foot and ankle. The three-dimensional range of motion (ROM) of the ankle joint complex, before and after ankle arthrodesis and after implantation of three currently used total ankle prostheses, was investigated.
The three-dimensional ROM was determined in six fresh-frozen cadaver leg specimens using a 6-df device with an axial load of 200 N and a four-camera high-speed video system. A moment of 100 Nm was applied to the footplate to determine the ROM in the sagittal (dorsiflexion and plantarflexion) and frontal (inversion and eversion) planes. The same moment was applied to the tibia to determine the ROM for the internal and external tibial rotation. The measurements were performed for the normal ankle, the fused ankle, and the AGILITY, HINTEGRA, and S.T.A.R. prostheses.
Compared to the normal condition, the ROM for dorsiflexion and plantarflexion was changed for all surgical interventions. The changes were highest for the ankle arthrodesis. The changes due to the prostheses were significantly less than the changes due to ankle arthrodesis. Compared to the normal condition, the total ROM for inversion/eversion was slightly decreased by the fused ankle and not changed by the three-component prostheses (HINTEGRA, S.T.A.R.). However, the ROM for inversion/eversion was significantly higher for the two-component prosthesis, AGILITY. The ROM for internal and external tibial rotation was not altered by the AGILITY and HINTEGRA ankle, but it was significantly reduced by the ankle arthrodesis. S.T.A.R. showed a significant shift of the total ROM toward internal tibial rotation.
The three tested ankle joint prostheses changed the ROM of the ankle joint complex less than ankle fusion did. Total ankle prostheses were shown to replicate normal joint ROM closely. However, ankle arthrodesis was found to reduce the ROM substantially in all three planes: the sagittal, frontal, and horizontal planes.
With respect to the ROM, total ankle replacement changes the natural ankle joint condition less than ankle arthrodesis, which reduces the ROM in all three planes and might increase stress in adjacent structures. The prosthesis that replicated the normal ankle joint ROM best was the one with the most anatomical design.
本研究的目的是确定当前踝关节假体的设计在多大程度上模仿了足踝关节的独特需求。研究了踝关节融合术前后以及三种目前使用的全踝关节假体植入后踝关节复合体的三维活动范围（ROM）。
使用轴向载荷为200 N的6自由度装置和四摄像头高速视频系统，在六个新鲜冷冻尸体小腿标本中测定三维ROM。向脚板施加100 Nm的力矩，以确定矢状面（背屈和跖屈）和额状面（内翻和外翻）的ROM。向胫骨施加相同的力矩，以确定胫骨内旋和外旋的ROM。对正常踝关节、融合踝关节以及AGILITY、HINTEGRA和S.T.A.R.假体进行测量。
与正常情况相比，所有手术干预后背屈和跖屈的ROM均发生了变化。踝关节融合术的变化最大。假体引起的变化明显小于踝关节融合术引起的变化。与正常情况相比，融合踝关节使内翻/外翻的总ROM略有降低，而三件式假体（HINTEGRA、S.T.A.R.）则未使其改变。然而，两件式假体AGILITY的内翻/外翻ROM明显更高。AGILITY和HINTEGRA踝关节未改变胫骨内旋和外旋的ROM，但踝关节融合术使其明显降低。S.T.A.R.显示总ROM明显向胫骨内旋偏移。
三种测试的踝关节假体对踝关节复合体ROM的改变小于踝关节融合术。全踝关节假体显示出能紧密复制正常关节ROM。然而，发现踝关节融合术在矢状面、额状面和水平面这三个平面上均大幅降低了ROM。
就ROM而言，全踝关节置换术对自然踝关节状况的改变小于踝关节融合术，踝关节融合术会在所有三个平面上降低ROM，并可能增加相邻结构的应力。复制正常踝关节ROM最佳的假体是解剖设计最合理的假体。
