Cartilage tissue engineering: Role of mesenchymal stem cells along with growth factors & scaffolds.

Articular cartilage injury poses a major challenge for both the patient and orthopaedician. Articular cartilage defects once formed do not regenerate spontaneously, rather replaced by fibrocartilage which is weaker in mechanical competence than the normal hyaline cartilage. Mesenchymal stem cells (MSCs) along with different growth factors and scaffolds are currently incorporated in tissue engineering to overcome the deficiencies associated with currently available surgical methods and to facilitate cartilage healing. MSCs, being readily available with a potential to differentiate into chondrocytes which are enhanced by the application of different growth factors, are considered for effective repair of articular cartilage after injury. However, therapeutic application of MSCs and growth factors for cartilage repair remains in its infancy, with no comparative clinical study to that of the other surgical techniques. The present review covers the role of MSCs, growth factors and scaffolds for the repair of articular cartilage injury.

Reference values of M-mode echocardiographic parameters and indices in conscious Labrador Retriever dogs.

Breed-wise standard echocardiographic values in dogs have been reported as there is variation in body and chest conformation which limits the application of data of one breed for other breed. Labrador Retrievers being originated from hunting dogs, might have different echocardiographic values from standard normal range of other dog breeds. So, the present study was aimed to determine the M-mode echocardiographic reference ranges in Labrador Retriever dogs and to evaluate the effect of body weight and gender on these parameters. The data obtained were also compared with that of the other dog breeds. Conscious clinically healthy Labrador Retriever dogs (n=24) of both sexes were made the subject of the study. All the measurements were made from a right parasternal long axis left ventricular outflow tract view and the parameters measured were: left ventricular dimensions, left ventricular function, left ventricular volumes, left atrial and aortic root diameter and mitral valve parameters. Data obtained were also compared with that available for other dog breeds. Significant correlation (P<0.05) with body weight was obtained for some of the left ventricular, atrial and mitral valve parameters, being strong for LAD, AOD, LVIDd, LVIDs, IVSd and IVSs (r>0.5); moderate for LVPWd, LVPWs, EPSS, EF Slope and SV (r=0.3 to 0.5); weak for EDV and ESV (r<0.3). Non-significant effect of gender was seen on all the echocardiographic parameters. However, some of the parameters had a significant breed effect. It is expected that the obtained data will be valuable for the progress of studies on small animal cardiology.

An in vitro biomechanical investigation of an interlocking nail system developed for buffalo tibia.

OBJECTIVE: The objectives of the study were to determine the mechanical properties of a customized buffalo interlocking nail (BIN), intact buffalo tibia, and ostectomized tibia stabilized with BIN in different configurations, as well as to assess the convenience of interlocking nailing in buffalo tibia. MATERIALS AND METHODS: The BIN (316L stainless steel, 12 mm diameter, 250 mm long, nine-hole solid nails with 10° proximal bend) alone was loaded in compression and three-point bending (n=4 each); intact tibiae and ostectomized tibiae (of buffaloes aged 5-8 years, weighing 300-350 kg) stabilized with BIN using 4.9 mm standard or modified locking bolts (4 or 8) in different configurations were subjected to axial compression, cranio-caudal three-point bending and torsion (n=4 each) using a universal testing machine. Mechanical parameters were determined from load-displacement curves and compared using Kruskal-Wallis test (p<0.05). RESULTS: Intact tibiae were significantly stronger than BIN and bone-BIN constructs in all testing modes. The strength of fixation constructs with eight locking bolts was significantly more than with four bolts. Overall strength of fixation with modified locking bolts was better than standard bolts. Based on technical ease and biomechanical properties, cranio-caudal insertion of bolts into the bone was found better than medio-lateral insertion. CLINICAL SIGNIFICANCE: The eight bolt BIN-bone constructs could be useful to treat tibial fractures in large ruminants, especially buffaloes.