Biomechanical Property Comparison Of Ligment Reconstruct Of Distal Tibiofibular Syndesmosis In Different Direction

Objective The distal tibiofibular syndesmosis injuries havebeen correlated w ith poor functional outcomes and thedevelopment of osteoarthritis.Ligment reconstruct has beenshown to play a large part in the stability of the syndesmosisjoint.But the means to reconstruct are different andconflicting.The experiment is to analyze the biomechanicalproperty of ligment reconstruct of distal tibiofibular syndesmosisin different direction, to guide ligment reconstruction in clinic.Methods6specimen of fresh adult ankle were used. We usethe peroneus longus tendon for reconstruct of the distaltibiofibular ligaments.The models were divided to two groups(Aand B).A group reconstruct in horizontal direction parallel to anterior tubercle of tibial.B group reconstruct in the obliquedirection simulating the anterior inferior tibiofibular ligament. Incross section we set three direction in two groups. Direction1:direction of interosseous ligament． Direction2:directionbetween the interosseous ligament and the distal anteriortibiofibular ligament. Direction3:direction between the distalposterior tibiofibular ligament and the interosseousligament．Biomechanical test and press sensitive film patchtechnique were used to measure the strain,displacement of medial and lateral ankle,strength and rigidity of distaltibiofibular,load area and contact feature of tibiotalar joint ineach reconstruct. Experimental mechanics models requirestructure, load and mechanical properties as consistent aspossible to ensure the accuracy of experiment and the average ofload. All specimens using fresh adult specimens. Physiologicalload (500N)was imposed on the specimen in grade maintainingthe specimen fresh moist state. prior to the test small-scale loadwas imoposed to eliminate the time effect of the bone, relaxationand creep change effect. Then load the formal experiment andcollect data. optimization method was used to evaluate thestability of the ankle. Results The test showed ligment reconstruct in the obliquedirection between the distal anterior tibiofibular ligament and theinterosseous ligament is better than other ways of reconstruct inthe aspect of strength and three different rigidity (Axialstiffness,horizontal shear stiffness,torsional rigidity)of distaltibiofibular.we use Advantage Rigidity to evaluate the totalmechanical property in different reconstruct and different loadwith optimization method. The result shows B group is superiorto A group, reconstruct between the distal anterior tibiofibularligament and the interosseous ligament is superior to otherdirection. Press sensitive film patch test showed ligmentreconstruct in the oblique direction between the distal anteriortibiofibular ligament and the interosseous ligament is better thanother ways of reconstruct,the tibiotalar joint contact area isbig,the contact stress is small and average. the difference wassignificant(P<0.05)。Conclusion Ligment reconstruct in the obique directionbetween the distal anterior tibiofibular ligament and theinterosseous ligament can improve the biomechanical property, it also can enhance the load bearing ability of ankle, it is theexcellent method of ligment reconstruct of distal tibiofibularsyndesmosis.