Bilateral External Torque CT, a Novel Diagnostic Tool for Detection of Syndesmotic Insufficiency

Study population: the investigator set them sample size to 30 patients.Primary endpoint (concerning both study questions): is the applied torque measurement in Newton meters (maximum up to 7.5 Nm) up to the pain tolerance limit. For the chronic injuries, a minimum of 5 Nm should be achieved. If this is not possible due to pain, an intra-articular infiltration into the upper ankle joint with 5ml Ropivacaine 2% is performed under sterile conditions.In addition, fibula translation while exercising the maximum tolerated External Torque CT (maximum up to 7.5 Nm).Secondary endpoint (1st study question): the comparison to stress fluoroscopy without anesthesia and under anesthesia.Secondary endpoint (2nd study question): the comparison of patients with and without symptoms. Secondary endpoint in patients who received intra-articular infiltration is the increase in tolerated Newton meters.

Inclusion Criteria:Written informed consentPatient age of ≥18 yr and ≤75 yr.Proven acute (<4 weeks) syndesmosis injury (anterior and posterior) on MRI.Proven chronic (>2 months) syndesmosis injury (anterior and posterior) on MRI with/without surgical stabilization performed.Healthy opposite sideExclusion Criteria:A dependency between patient sponsor and/or project managementPregnancy (contraindication for CT): in women of childbearing age, a pregnancy test is performed in any caseSt.n. previous operation(s) of the affected lower extremity (specifically of the ankle joint).Severe deformities (osteoarthritis with limited function upper and lower ankle joint, metatarsophalangeal joint).