第四、五跖跗关节活动度的实验研究及临床意义

Ranges of motion of the fourth and fifth tarsometatarsal joints and their clinical significance： an experimental study

目的测量第四、五跖跗关节在不同平面的运动范围，从而了解其活动度，为临床治疗Lisfrane损伤时选择内固定还是融合提供参考。方法12例成人新鲜冰冻足部标本，在不同方向对第四、五跖骨头加载下用三维坐标仪测量活动度；然后固定第四、五跖骨，再测其共同的活动度。结果在500N载荷下，第四跖跗关节矢状面极限活动度为18．5°±2．5°，水平面为2．8°±0．7°；第五关节跖跗关节矢状面极限活动度为20．2°±2．8°，水平面为7．4°±1．7°；固定第四、五跖骨后，加载第四跖骨头时矢状面的极限活动度为14．5°±1．3°，水平面为2．3°±0．7°，加载第五跖骨头时矢状面的极限活动度约为14．8°±1．9°，水平面约为2．4°±0．8°。结论第四、五跖跗关节具有相当的活动度，远大于内侧柱，且活动具有协同作用，临床上应尽可能保留此两关节的活动功能。

Objective To measure ranges of motion （ROMs） of the fourth and fifth tarsometatarsaljoints which can be served as significant evidence for clinical choice of fixation or fusion when dealing with Lisfranc injury. Methods Twelve fresh-frozen specimens of adult foot were used for measuring ROMs of the fourth and fifth tarsometatarsal joins under different forces at different directions. Next, the 2 metatarsals were fixed together to measure the ROMs of the joints under the same conditions. Results Under a load of 500 N, the ROMs in the sagittal plane of the fourth and fifth tarsometatarsal joints were 18.5° ± 2. 5° and 20. 2° ± 2. 8° respectively; the ROMs in the transverse plane of the fourth and fifth tarsometatarsal joints were 2.8° ± 0.7° and 7. 4° ± 1.7° respectively. After the 2 metatarsals were fixed together, when the load was added onto the head of the fourth metatarsal head, the ROMs in the sagittal and transverse planes were 14. 5°± 1.3° and 2. 3° ± 0. 7° respec- tively; when the load was onto the head of the fifth metatarsal, the ROMs in the sagittal and transverse planes were 14. 8° ± 1.9° and 2. 4° ± 0. 8° respectively. Conclusions The fourth and fifth tarsometatarsal joints have notable ROMs, much wider than that of the medial column. Since the ROMs of the 2 joints has a synergistic effect, we should try to retain the motive function of the 2 joints as much as possible in clinic.