Biomechanical evaluation of two extracapsular techniques for cranial cruciate ligament reconstruction in cadaver dogs

Cranial cruciate ligament rupture (CCLR) is one of the most important orthopedic conditions in dogs, leading to joint instability, pain, osteoarthritis and eventually to meniscal injuries. Several surgical techniques have been described to reestablish joint stability following CCLR, including extracapsular procedures. This study compared the biomechanical effects of two extracapsular stabilization techniques (lateral fabello-tibial suture-LFTS, and modified retinacular imbrication technique-MRIT) using nylon leader line following experimental CCLR in cadaver dogs. Twenty canine cadaveric stifles were used. Joint stiffness, cranial and caudal tibial displacement were evaluated in 4 different experimental scenarios: intact stifle, stifle with CCLR, CCLR treated with lateral fabello-tibial suture (LFTS), and CCLR treated with modified retinacular imbrication technique (MRIT). Results: Mean cranial tibial displacement increased progressively from intact to MRIT, LFTS and CCRL stifles. MRIT resulted in less caudal drawer motion than LFTS. Joint stiffness did not differ significantly between LFTS and MRIT treated stifles. Conclusion: LFTS and MRIT increase joint stability but MRIT is more effective; however none of the techniques studied was able to restore original intact stifle stiffness. Clinical implications of the results presented remain to be determined but kinetic gait analysis studies are warranted to determine whether this biomechanical advantage translates into improved hind limb function in dogs.