Buchner H H, Savelberg H H, Becker C K
Department of General and Large Animal Surgery, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Vet Q. 1996;18 Suppl 2:S70-4.
An analysis of joint moments was used to study the biomechanical implications, load redistribution and kinematic pattern following desmotomy of the accessory ligament of the deep digital flexor tendon (AL) in adult horses. Recordings of 6 sound horses were made before and 10 days after desmotomy of the AL of the right forelimb at the walk and the trot. Kinematic recordings of the right forelimb and the left distal forelimb were made using the CODA-3 system. Kinetic recordings of the ground reaction forces in both forelimbs were made using a Kistler force plate simultaneously with the kinematic recordings. Radiographic localisation of the CODA-3 markers in both distal limbs allowed an analysis of coffin and fetlock joint moments, moment arms and forces in the digital flexor tendons. No transfer of load from the operated to the contralateral limb was found. In the operated limb the total joint moment of the coffin joint decreased substantially due to a reduced moment arm of the vertical ground reaction force component during the entire stance phase, while the fetlock joint moment decreased only slightly. To compensate for the loss of AL function, the superficial digital flexor tendon (SDFT) took a higher load during midstance, while at the end of the stance phase, the deep digital flexor tendon (DDFT) carried a higher load with a marked load peak just before heel off. While the compensation was adequate during midstance (no changes in maximal hyperextension of the fetlock joint), a prolonged hyperextension of the fetlock joint together with a rapid flexion at the start of the swing phase indicated that the DDFT was unable to compensate completely for the loss of AL function. It was concluded that the changes in total joint moments and increases in loading of the SDFT and DDFT allow locomotion without serious overloading of the compensating tendons following AL desmotomy.
通过分析关节力矩，研究成年马深指屈肌腱副韧带（AL）切断术后的生物力学影响、负荷再分配和运动模式。对6匹健康马在右前肢AL切断术前及术后10天的行走和小跑状态进行记录。使用CODA-3系统对右前肢和左前肢远端进行运动学记录。在前肢进行地面反作用力的动力学记录，同时使用奇石乐测力板进行运动学记录。通过对两远端肢体CODA-3标记物的X线定位，分析蹄关节和球节的力矩、力臂及指屈肌腱中的力。未发现负荷从手术肢体转移至对侧肢体。在手术肢体中，由于整个站立期垂直地面反作用力分量的力臂减小，蹄关节的总关节力矩大幅下降，而球节力矩仅略有下降。为补偿AL功能的丧失，浅指屈肌腱（SDFT）在站立中期承受更高负荷，而在站立期末期，深指屈肌腱（DDFT）承受更高负荷，在足跟离地前有明显的负荷峰值。虽然在站立中期补偿是充分的（球节最大过伸无变化），但球节的长时间过伸以及摆动期开始时的快速屈曲表明DDFT无法完全补偿AL功能的丧失。研究得出结论，关节总力矩的变化以及SDFT和DDFT负荷的增加使得在AL切断术后，运动时补偿肌腱不会出现严重过载。
