Comparative morphological interpretations on the bones of the pelvic limb of New Zealand rabbit (Oryctolagus cuniculus) and domestic cat (Felis domestica)

Extracellular Vesicles from Adipose-Derived Mesenchymal Stem Cells Improve Ligament-Bone Integration After Anterior Cruciate Ligament Primary Repair in Rabbit

BACKGROUNDS

In this research, we want to find out whether extracellular vesicles (EVs) from adipose-derived mesenchymal stem cells (MSCs) can improve ligament-bone integration after primary Anterior Cruciate Ligament (ACL) repair by performing immunological and biomechanical tests.

METHODS

All of the rabbits underwent ACL resection at the proximal attachment to the femur bone, and then were divided into four groups. We performed an ELISA examination from the tissue at the bone-ligament interface of iNOS, CD206, MMP-3, and TIMP-1 to evaluate their levels at the inflammatory stage at the end of the first week. Immunoexpression of type I and III collagen and failure load biomechanical tests were performed at the end of the sixth week.

RESULT

The group that underwent ACL repair with EVs augmentation had significantly higher levels of CD206, significantly lower MMP-3 levels, and significantly higher TIMP-1 levels in the first week. The iNOS levels in the group that underwent ACL repair with EVs augmentation were significantly different compared to the control group that did not receive any. The number of type I collagen fibers and the failure load levels in the group that underwent ACL repair with EVs augmentation were significantly higher.

CONCLUSIONS

EVs from adipose-derived MSCs can improve the outcome of primary ACL repair in rabbits by regulating the inflammatory process during the healing period.

Radiomorphometric analysis of the metapodial bones in the Scottish fold cats

Scottish Fold cats (Felis catus, Linnaeus 1758) are one of the most well-known and popular cat breeds in the world, characterized by their folded ears attached to the head. Very frequently, cats fall prey of different trauma and accidents that can cause bone fractures especially in the metapodial bones. The method of radiometry is used in veterinary practice to visualize and measure different parts of the animal skeleton. The aim of this study was to assess the linear parameters derived from radiographic images of the metacarpals and metatarsals in Scottish Fold cats and additionally detecting potential sexual dimorphism. Radiographic images of 24 adult Scottish Fold cats (12 male and 12 females) of different ages and weights were analysed. Six linear measurements of the metapodial bones were evaluated to investigate any differences between the sexes. The linear radiometric measurements of the five metacarpals (MC1-5) and the four metatarsals (MT2-5) bones were larger in male metapodial bones than that of female cats. The maximum length (Ml) of the MC1 and MC2 was statistically different between sex, respectively, (p = 0.001) and (p = 0.05). The others metacarpal bones were different in mostly all linear parameters but not statistically significant. The most significant differences between sexes were observed in the parameter of width proximal end (Wp) of MC1-3 (p = 0.001) and MC4 (p = 0.05). More statistical different was MT2 and less MT3. The linear parameter of Bd of the MT4 was the most different statistically between sex (p = 0.001). The results of the study will be useful in function of comparative anatomy, in veterinary clinical practice, in zoo archaeology and in the veterinary forensic investigation.

Three-dimensional modelling and morphological investigation of the bones of the Articulatio genus using computed tomography images in Van cats

In this study, it was aimed to make three-dimensional reconstruction of the stifle joint computed tomography (CT) images of the Van cats, to obtain their osteometric measurements, and to determine the statistical biometric differences of these measurement values in terms of both sexual dimorphism and homotypic variations. A total of 16 healthy adult Van cats of both sexes were used. The stifle joints of the cats were scanned with a CT device and images were obtained. Three-dimensional reconstructions of the bony structures of the stifle joint were performed using CT images using the MIMICS 20.1 modelling program. Then, osteometric measurements were calculated, and statistical analysis was performed. When the morphometric measurement values were examined in terms of gender, it was observed that almost all of the osteometric measurement values of the stifle joint in Van cats (except SPW measurement) were higher in male cats. According to homotypic variations, right side TPW (p = 0.009), TPCMA (p = 0.003) and TPMCA (p = 0.032) measurement values in female cats and right side TPLCA (p = 0.002) measurement values in male cats were found to be statistically significantly higher than the left side from the measurements of only the proximal tibia (p < 0.05). In general, although there were negative correlations between morphometric measurement values with age and body weight, mostly strong positive correlations were seen. As a result, statistical differences of the biometric values and anatomical features of the stifle joint between the sexes in Van cats between the sexes were examined using CT and a three-dimensional modelling program.

Establishment of an ultrasound-guided protocol for the assessment of hip joint osteoarthritis in rabbits-A sonoanatomic study

Ultrasound (US) has emerged as one of the most applied imaging tools to diagnose musculoskeletal disorders and assist in guided intra-articular administrations. Nevertheless, in evaluating the rabbit hip joint, there is a need for an ultrasonographic approach. Therefore, this study aimed to describe the hip sonoanatomy, develop and validate a US-guided protocol to assess the hip joint in rabbits and apply this protocol in vivo. This study was carried out in three phases, phase I: a pilot cadaveric study, to assess the applicability of different US approaches in the hip of rabbits and, consequently, develop a detailed US-guided protocol (2 rabbit cadavers, n = 4 hips); phase II: validation of the established US-guided protocol through a numerical scoring system in healthy joints (11 rabbit cadavers, n = 22 hips), and, lastly, phase III: application of the US-guided protocol in vivo in osteoarthritic joints (5 rabbits, n = 5 hips). A total of six planes were validated, two in the ventral approach and four in the dorsal approach. The ventral transverse plane was deemed more informative regarding the hip joint sonoanatomy, enabling the identification of a greater number of structures when compared to the other planes. Nevertheless, this study suggested that the isolated application of a plane was deemed insufficient for a complete and detailed evaluation of the hip joint anatomy, rendering it necessary to employ other planes complementarily. Furthermore, the established US-guided protocol allowed a definitive diagnosis of OA, and osteophytes and capsular hypertrophy were among the defects most frequently detected. This novel study provided US anatomical landmarks for forthcoming therapeutic research and monitoring of OA development, granting the accurate identification of osseous and cartilaginous defects.

Influence of Screw-Hole Defect Size on the Biomechanical Properties of Feline Femora in an Ex Vivo Model

OBJECTIVE

 The study aims to evaluate the biomechanical properties of feline femora with craniocaudal screw-hole defects of increasing diameter, subjected to three-point bending and torsion to failure at two different loading rates.

STUDY DESIGN

 Eighty femoral pairs were harvested from adult cat cadavers. For each bending and torsional experiment, there were five groups (n = 8 pairs) of increasing craniocaudal screw-hole defects (intact, 1.5 mm, 2.0 mm, 2.4 mm, 2.7mm). Mid-diaphyseal bicortical defects were created with an appropriate pilot drill-hole and tapped accordingly. Left and right femora of each pair were randomly assigned to a destructive loading protocol at low (10 mm/min; 0.5 degrees/s) or high rates (3,000 mm/min; 90 degrees/s) respectively. Stiffness, load/torque-to-failure, energy-to-failure and fracture morphology were recorded.

RESULTS

 Defect size to bone diameter ratio was significantly different between defect groups within bending and torsional experiments respectively (intact [0%; 0%], 1.5 mm [17.8%; 17.1%], 2.0 mm [22.8%; 23.5%], 2.4 mm [27.8%; 27.6%], 2.7 mm [31.1%; 32.4%]) (p < 0.001). No significant differences in stiffness and load/torque-to-failure were noted with increasing deficit sizes in all loading conditions. Screw-hole (2.7 mm) defects up to 33% bone diameter had a maximum of 20% reduction in bending and torsional strength compared with intact bone at both loading rates. Stiffness and load/torque-to-failure in both bending and torsion were increased in bones subjected to higher loading rates (p < 0.001).

CONCLUSION

 Screw-hole defects up to 2.7 mm did not significantly reduce feline bone failure properties in this ex vivo femoral study. These findings support current screw-size selection guidelines of up to 33% bone diameter as appropriate for use in feline fracture osteosynthesis.