Two different approaches for novel extracapsular cranial cruciate ligament reconstruction: An in vitro kinematics study

OBJECTIVE: To analyse the best combination of isometric points with the best kinematic results between two different approaches of TightRope® cranial cruciate ligament reconstruction. MATERIALS AND METHODS: Cranial drawer, cranial tibial thrust, internal/external, range of motion and varus/valgus tests were passively performed in different stifle conditions: cranial cruciate ligament-intact/deficient, after F2-T2/F2-T3 TR reconstruction at 22-44-99 N of tension. Data were acquired by a custom-made navigation system. RESULTS: The cranial drawer test showed recovery of laxity only at 99 N in both approaches. Significant laxity reduction (cranial tibial thrust) was present at only the F2-T2 point. Differences were noted in internal/external and varus/valgus rotation between the cranial cruciate ligament-intact and TightRope® stifles at all of the implant tensions. The range of motion underlined significantly lower laxity values following the F2-T2/F2-T3 reconstruction at all of the evaluated implant tensions. CLINICAL SIGNIFICANCE: The best isometric site was at the F2-T2 point, however significant differences in the amount of laxity between the two techniques were limited to the cranial tibial thrust and internal/external test. The F2-T2 technique was the best consideration for clinical application because it is relatively easy to perform, repeatable and results in good stifle stability with low morbidity and complications.