Quantifying meniscal kinematics in dogs

Evaluation of Meniscal Load and Load Distribution in the Sound Canine Stifle at Different Angles of Flexion

OBJECTIVES

 The aim of the study was to investigate the contact mechanics and kinematic changes in the stifle in different standing angles.

STUDY DESIGN

 We performed a biomechanical ex vivo study using pairs of canine cadaver hindlimbs. Motion sensors were fixed to the tibia and the femur for kinematic data acquisition. Pressure mapping sensors were placed between the femur and both menisci. Thirty percent bodyweight was applied to the limbs with the stifle in 125, 135, or 145 degrees of extension.

RESULTS

 Stifle flexion angle influences femoromeniscal contact mechanics significantly. The load on both menisci was significantly higher for 125 and 135 degrees in comparison to 145 degrees. Additionally, the center of force was located significantly more caudal when comparing 125 to 145 degrees in the medial meniscus as well as in both menisci combined.

CONCLUSION

 The angle of knee flexion significantly impacts the contact mechanics between the femur and the meniscus. As the knee flexes, the load on both menisci increases.

Evaluation of Meniscal Load and Load Distribution in the Canine Stifle after Tibial Plateau Levelling Osteotomy with Postoperative Tibia Plateau Angles of 6 and 1 Degrees

OBJECTIVES

 The aim of the study was to investigate the kinetic and kinematic changes in the stifle after a tibial plateau levelling osteotomy (TPLO) with a postoperative tibia plateau angle (TPA) of either 6 or 1 degrees.

STUDY DESIGN

 Biomechanical ex vivo study using seven unpaired canine cadaver hindlimbs from adult Retrievers.Hinge plates were applied and a sham TPLO surgery was performed. Motion sensors were fixed to the tibia and the femur for kinematic data acquisition. Pressure mapping sensors were placed between femur and both menisci. Thirty per cent bodyweight was applied to the limbs with the stifle in 135 degrees of extension. Each knee was tested with intact cranial cruciate ligament (CCL), deficient CCL, 6 degrees TPLO and 1degree TPLO.

RESULTS

 Transection of the CCL altered kinematics and kinetics. However, comparing the intact with both TPLO set-ups, no changes in kinematics were detected. After 1 degree TPLO, a significant reduction in the force acting on both menisci was detected (p = 0.006).

CONCLUSIONS

 Tibial plateau levelling osteotomy restores stifle kinematics and meniscal kinetics after transection of the CCL ex vivo. The contact force on both menisci is reduced significantly after TPLO with a TPA of 1 degree. Increased stifle flexion might lead to caudal tibial motion.

Comparative anatomy and morphology of the knee in translational models for articular cartilage disorders. Part I: Large animals

BACKGROUND

The human knee is a complex joint, and affected by a variety of articular cartilage disorders. Large animal models are critical to model the complex disease mechanisms affecting a functional joint. Species-dependent differences highly affect the results of a pre-clinical study and need to be considered, necessitating specific knowledge not only of macroscopic and microscopic anatomical and pathological aspects, but also characteristics of their individual gait and joint movements.

METHODS

Literature search in Pubmed.

RESULTS AND DISCUSSION

This narrative review summarizes the most relevant anatomical structural and functional characteristics of the knee (stifle) joints of the major translational large animal species, comprising dogs, (mini)pigs, sheep, goats, and horses in comparison with humans. Specific characteristics of each species, including kinematical gait parameters are provided. Considering these multifactorial dimensions will allow to select the appropriate model for answering the research questions in a clinically relevant fashion.

Titanium-Alloy Anchoring System as a Suitable Method of Extracapsular Repair

Objective: To characterize the effect of a titanium-alloy anchoring system (TAS) on the motion of the cranial cruciate ligament (CrCL) deficient stifle. To compare the motion with the TAS to that of the CrCL-intact and CrCL-deficient stifle.

Study Design: Each canine pelvic limb was mounted in a loading jig under 30% body weight. Motion data was collected using an electromagnetic tracking system at stifle angles of 125°, 135°, and 145° with the CrCL-intact, CrCL-deficient and the TAS applied.

Results: Total translation of the CrCL-deficient stifle following the TAS was reduced, but remained greater than the CrCL-intact stifle at angles of 125°, 135°, and 145°. Internal rotation of the TAS groups was greater than the CrCL-intact group at 145°, but not 125° and 135°. Varus motion of the TAS group was decreased compared to the CrCL-deficient group, but increased compared to the CrCL-intact group at angles of 125°, 135°, and 145°.

Conclusion: Total translation and internal rotation of the CrCL-deficient stifle following the TAS differed from that of the CrCL-intact stifle. However, the TAS reduced total translation and internal rotation of the tibia relative to the femur in the CrCL-deficient stifle to levels that may yield clinically acceptable results.

Prevalence and Risk Factors for Bilateral Meniscal Tears Identified during Treatment for Cranial Cruciate Ligament Disease Via Tibial Plateau Levelling Osteotomy in Dogs

OBJECTIVE

 The aim of this study was to report the prevalence and risk factors of bilateral meniscal tears during a tibial plateau levelling osteotomy (TPLO).

METHODS

 Data from 362 dogs that underwent staged or simultaneous TPLO between January 2006 and April 2019 were retrospectively collected. Variables such as breed, sex, weight change and intervals between surgeries were analysed with logistic regression. Preoperative tibial plateau angle, age, cranial cruciate ligament status and body weight were analysed with a generalized linear mixed model. All analyses were performed to assess the likelihood of bilateral meniscal tears versus unilateral tears and no tears. Correlation of meniscal tears between stifles was assessed with Cohen's kappa coefficient.

RESULTS

 Prevalence of bilateral meniscal tears was 48.0% (95% confidence interval [CI]: 43.0-53.0%). There was moderate agreement of the presence of meniscal tears between stifles (Cohen's kappa coefficient = 0.41, 95% CI: 0.31-0.51).The odds for bilateral meniscal tears were higher for Rottweilers (odds ratio [OR:] 4.5 [95% CI 1.1-30.3], p = 0.033), older dogs (OR: 1.2 [95% CI: 1.1-1.4 per year], p < 0.0001), smaller dogs (OR: 0.98 [95% CI: 0.97-0.99 per 0.45-kg], p = 0.001), stifles with complete cranial cruciate ligament tears (OR: 21.1 [95% CI: 7.1-62.4], p < 0.0001).

CONCLUSION

 Contralateral meniscal tears, breed, older age, lower patient weight and complete cranial cruciate ligament tear were significant risk factors for bilateral meniscal tears. Surgeons can use these results to determine prognoses and propensities for meniscal tears in at-risk dogs.

Review of kinematic analysis in dogs

Objective gait analysis techniques aid investigators in the study of motion. Kinematic gait analysis techniques that objectively quantitate motion are valuable tools used to understand normal and abnormal motion in domestic animals. Recent advances in video technology have made the study of motion more readily accessible. Available systems can document gait in two or three dimensions (2D or 3D, respectively). Knowledge of fundamental gait analysis concepts is critical to generating meaningful data. The objective of this report is to review principles of kinematic data collection and analyses, with a focus on differences between 2D and 3D systems.

Quantifying dog meniscal volume at 1.5T and 3.0T MRI

The dog has been used extensively as an experimental model to study meniscal treatments such as meniscectomy, meniscal repair and regeneration. Accurate quantification of meniscal size and morphology are a crucial step for developing models of the meniscus. 3.0T magnetic resonance imaging (MRI) has been found to be highly accurate in analyzing the meniscus in both clinical and research fields. However, 3.0T MRI systems are still uncommonly used in veterinary medicine. The goal of the study was to compare meniscal volume measurements from 1.5T MRI system with 3.0T MRI system using proton density sequence, a clinically relevant protocol. The MR images were segmented to reconstruct 3D surface representations of both medial and lateral menisci to compare the meniscal volumes measurements. Average volume differences were 8.8% (P=0.42) and 8.9% (P=0.535) for medial and lateral meniscus, respectively. No significant volume differences were found between 1.5T and 3.0T magnetic resonance (MR) measurements, with high Pearson's correlation coefficient of r > 0.8 and the intraclass correlation coefficient (ICC) of 0.899. For inter- and intra-observer reproducibility, high correlation (ICC = 0.942 and 0.814) was observed, but with high variability for intra-observer reproducibility (lower bound 0.478, upper bound 0.949). We have shown that common clinical MR scanners and pulse sequences can be used to quantify dogs' meniscal volumes with good reproducibility. We believe that repeatable measurements of meniscal volumes using MR may provide a useful capability for assessment of postoperative results following meniscal treatments such as meniscectomy and meniscal regeneration.

Large Animal Models for Anterior Cruciate Ligament Research

Large animal (non-rodent mammal) models are commonly used in ACL research, but no species is currently considered the gold standard. Important considerations when selecting a large animal model include anatomical differences, the natural course of ACL pathology in that species, and biomechanical differences between humans and the chosen model. This article summarizes recent reports related to anatomy, pathology, and biomechanics of the ACL for large animal species (dog, goat, sheep, pig, and rabbit) commonly used in ACL research. Each species has unique features and benefits as well as potential drawbacks, which are highlighted in this review. This information may be useful in the selection process when designing future studies.