Investgating The Values Of Ankle X-ray Image In Pronation-external Rotation Stress To Diagnose Distal Tibiofibular Syndesmosis Instability

Objective:Measure ankle joint X-ray image in pronation-external rotation stress,to approach its application and significance in diagnosis of distal fibiofibular syndesmosis instability.Methord:1.Sample choice:Chosing 20 patients whose ankle joint injuried with pain, swelling,bruise and couldn't stand with foot.Clinic test include:①Cotton test:Positive appearance is talus'activities exceeded its normal range inward or outward.②Press test: Hopinson suggested that positive appearance was pressing the middle leg cause pain in distal tibiofibular syndesmosis.③External rotation test:Boytin supposed the positive result was pain caused in distal tibiofibular syndesmosis or in interosseous membrane by external rotation force to foot,when patient sitted and knee flexed to 90°and ankle in neutral position.④Fibular translation test:Pushing fibula forward or backward cause abnormal activities and pain in distal tibiofibular syndesmosis is positive.Most patients couldn't endure these test if their injuries were serious.Cotton test and fibular translation test can be performed with local anesthesia or during operation.All 20 patients were doubted to have injuries in distal tibiofibular syndesmosis.2.Data measurement:20 patients(15 males and 5 females)with distal tibiofibular syndesmosises instability were photographed in normal anterior-posterior x-ray image and image in pronation-external rotation stress before healing.Target distance was 1.5m.The definition of pronation-external rotation stress x-ray image was inspector performed pronation-external rotation force to the foot of patients.If patient couldn't endure pain,we administrated local anesthesia by injection 2%lidocaine.Measure distal tibiofibular overlaps and gaps with vernier caliper.The parameters were analyzed statistically.Result:Distal tibiofibular gap increased and distal tibiofibular overlaps diminished even disappeared in the pronation-external rotation stress x-ray image than normal anterior-posterior x-ray image.The result was significant in statistics.Conclusion:A pronation-external rotation stress x-ray image performed for preoperative or postoperative evaluation of the integrity of the distal tibiofibular syndesmosis is comparatively reliable.