Analysis Of Cyclic Loading On The Biomechanical Properties Of Tibiofibular Syndesmosis Injury Reconstruction Using The Tendon Of Peroneus Longus

Objective Distal tibiofibular syndesmosis injury is more common in ankle fractures.At present,the treatment of distal tibiofibular syndesmosis injury is mainly composed of cortical bone screw, but the numbers of cortical layers,screw numbers,placement location and leaving time are still no uniform standard.Because of distal tibiofibular syndesmosis physiological Tiny movement characteristic, in recent years, more and more scholars advocate the elastic fixation method.Reconstructing distal tibiofibular syndesmosis injury with long peroneal tendon is suitable for physiological characteristics of Tiny movement.Study of cyclic loading on the biomechanical properties of distal tibiofibular syndesmosis injury reconstruction using the tendon of peroneus longus and provide basic theory for clinical choice of effective elastic fixation.Methods 8 specimens of fresh adult ankle were used.The models were divided to three groups( normal group(N),instability of group(I) and long peroneal tendon reconstruction group(B)). Measure 8 normal specimens contacting area S(cm2), contacting pressure PCP(N/cm2) with different postures(neutral,back stretch 200,plantar flexion 300) in pressure-sensitive technologies.Then all specimens measure the dynamic mechanics with Germany introduced HFP Zwik- 100 5100 blow frequency fatigue testing machine.At 1 hz frequency,axial loading of 750 n, 3000 times, simulating patients postoperative functional exercise walking gait,Respectively indifferent postures(neutral,back stretch after 200,plantar flexion 300,spin out 250) under dynamic cyclic loading experiments, the measurement of the tibial phil horizontal displacement(U) and vertical displacement(V). Then cut off 8 specimens of anterior tibiofibular ligament, measuring ankle instability condition under different positions(neutral,back stretch after 200,plantar flexion 300,spin out 250) of the cyclic load of tibiofibula longitudinal(U) and horizontal displacement value(V). Reconstruction with long peroneal tendons between anterior tibiofibular ligament and interosseous ligament. Fixing long peroneal tendons with 8 mm Interface screw,pressure-sensitive chip technology was used to measure articular contact area S(cm2), contact pressure PCP(N/cm2) in different positions and different pretension(20N, 40 N,60N,80N).Getting more suitable pretension by Statistical analysis.In this pretension, reconstructed model is set upfor the cyclic loading test, and analysis and compare the data with the cyclic loading test specimens of normal group.Results After distal tibiofibular syndesmosis injury, the dynamic displacement of the tibia and fibula is obvious abnormal, when compared with the normal specimens it showed significant difference(P < 0.05); Under long peroneal tendons reconstruction distal tibiofibular syndesmosis injury can reach the purpose of the elastic fixed, its dynamic separation displacement can be achieved or close to normal(P > 0.05);Under different pretension with long peroneal tendons under reconstruction distal tibiofibular syndesmosis injury has obvious influence on the stability of the ankle, and rebuilt in 60 n pretension is advisable.Conclusion Cyclic loading test of reconstruction distal tibiofibular syndesmosis injury under 60 N pretension using long peroneal tendon proved that dynamic mechanical properties of long peroneal tendon reconstruction was very superior,greatly improved the ankle motion,could adapt the talus compliance regulation,achieved andrestored the normal physiological function of ankle joint.The elastic fixation with long peroneal tendons for distal tibiofibular syndesmosis injury accords with it normal physiological structure, avoiding the conventional screw loosening or fatigue fracture, and provide the theoretical basis for clinical treatment of distal tibiofibular syndesmosis injury.