A comparison of Telos™ stress radiography versus Rolimeter™ in the diagnosis of different patterns of anterior cruciate ligament tears

Introduction: Our knowledge on anterior cruciate ligament (ACL) pathomechanics has increased. The diagnosis of partial ACL tears must be accurate in order to adjust the operative planning to anatomic status and injury severity. Instrumented measurement of knee laxity is a useful preoperative tool to quantify anterior tibial translation and several laximetry tests are available. Yet, their accuracy remains to be established. Hypothesis: Clinical examination combined to instrumented laximetry with Telos (TM) 15 kg and/or Rolimeter (TM) would increase their sensitivity and specificity in the diagnosis of various ACL injury patterns. Materials and methods: One hundred and seventy-seven patients were prospectively included. The ACL status was validated by arthroscopy. Around 69.5% had a complete ACL tear and 30.5% had a partial ACL tear. Results: Gross laxity with positive clinical tests was associated with complete ACL tears. Mean side-to-side difference was significantly greater with both laximetry methods in complete versus partial ACL tears. Laximetry results among different types of partial tears were not significantly different. Telos (TM) results were consistent with gross laxity confirmed by pivot-shift test, while this was not recorded with Rolimeter (TM). Gross laxity with clinical tests and anterior tibial translation more than 5 mm with Telos (TM) were substantially associated with complete ACL tears. Discussion: The combination of standard clinical examination with Telos (TM) was more accurate than with Rolimeter (TM) in the preoperative identification of the ACL injury pattern. Applying additional diagnostic tools can help the surgeon to preoperatively diagnose partial or complete ACL ruptures and propose an injury-specific surgical treatment.