1782: Defining the Elements of Successful Cranial Cruciate Ligament Repair
Grant Status: Closed
In our study, we investigated four common CrCL-deficient stifle surgical stabilization techniques. We implemented the tibial plateau leveling osteotomy (TPLO), tibial tuberosity advancement (TTA), lateral femorotibial suture (LFTS) and TightRope (TR) techniques in our computer simulation model working closely with a veterinary orthopedic surgeon.
Caudal cruciate ligament, lateral collateral ligament, and medial collateral ligament loads, translation and rotation of the tibia, and compressive forces between the femur and menisci were compared to the CrCL-intact stifle to determine which stabilization technique(s) most closely returned the CrCL-deficient stifle to normal. Our computer model simulations provide a biomechanical assessment of the efficacy of each stifle stabilization technique.
Tibial Plateau Leveling Osteotomy
Tibial plateau leveling osteotomy modifies the slope of the tibia by cutting the tibia with a surgical saw and rotating the portion of the tibia that interacts with the femur to alter the interaction between the tibia and femur. This technique was represented in our hind limb computer simulation model. Additionally, the extent of tibia fragment rotation, fragment tilt, and fragment cut radius used during surgery were incrementally altered to study the resulting ligament loads and residual tibial movement during walking and characterize the degree of stifle stabilization.
Tibial Tuberosity Advancement
Tibial tuberosity advancement also cuts a portion of the tibia using a surgical saw. In this surgical procedure, the anterior (front) portion of the tibia near the stifle is cut and repositioned further forward. This repositioning changes how the thigh muscles apply force to the stifle. This technique was also represented in the hind limb computer model using two surgical planning methods and resulting ligament loads and residual tibial movement were evaluated during walking.
Lateral femorotibial suture and TightRope techniques are two common extra-capsular (i.e., outside the joint capsule) techniques that provide stifle stability using sutures that stretch across the stifle joint. These sutures help prevent excessive movement of the stifle. These techniques were implemented in the hind limb computer model using elements that restrain stifle movement. The suture elements wrapped around bony geometry to replicate surgical procedures, and material properties were assigned to match the sutures used during surgery. Resulting ligament loads and residual tibial movement were evaluated during walking. Additionally, the clinical extra-capsular suture material properties (stiffness and tautness) were incrementally altered to study the resulting ligament loads and residual tibial movement during walking and characterize the degree of stifle stabilization as these parameters were varied.
Summary and On-Going Efforts
We are currently analyzing computer model simulation results for each surgical stabilization technique, and have published findings related to implementation of the TPLO and TTA in veterinary journals. In general, our findings indicate the CrCL-deficient stifle joint was more stable following each technique, but each technique affected the stifle joint somewhat differently. Additionally, we found that certain surgery-specific parameters affected stifle biomechanics and that anatomical characteristics influenced the efficacy of each technique differently. Further research is needed to explore whether a canine- specific or breed-specific approach may be warranted when choosing a stifle stabilization procedure for CrCL-deficient dogs.
Brown, N. P., Bertocci, G. E., & Marcellin-Little, D. J. (2013). Development of a Canine Stifle Computer Model to Evaluate Cranial Cruciate Ligament Deficiency. Journal of Mechanics in Medicine and Biology, 13(02). doi:10.1142/s0219519413500437
Brown, N. P., Bertocci, G. E., & Marcellin-Little, D. J. (2014). Evaluation of varying morphological parameters on the biomechanics of a cranial cruciate ligament-deficient or intact canine stifle joint with a computer simulation model. Am J Vet Res, 75(1), 26-33. doi:10.2460/ajvr.75.1.26
Brown, N. P., Bertocci, G. E., & Marcellin-Little, D. J. (2014). Canine stifle joint biomechanics associated with tibial plateau leveling osteotomy predicted by use of a computer model. Am J Vet Res, 75(7), 626-632. doi:10.2460/ajvr.75.7.626
Brown, N. P., Bertocci, G. E., & Marcellin‐Little, D. J. (2017). Canine cranial cruciate ligament deficient stifle biomechanics associated with extra‐articular stabilization predicted using a computer model. Veterinary Surgery, 46(5), 653-662.