This study identifies and compares the kinematic gait changes occurring in tibial plateau levelling osteotomy (TPLO) and cranial tibial wedge osteotomy (CTWO) limbs after transection of the cranial cruciate ligament (CrCL). Ten, healthy, adult beagle dogs were assigned to TPLO (five dogs) and CTWO (five dogs) groups. Hind limb kinematics were assessed, while dogs were trotted at speeds ranging from 2.0 to 2.3 m/s. The animals were evaluated preoperatively (prior to TPLO and CTWO surgery) and at both 8 and 12 weeks after surgery. Two-dimensional evaluation was synchronized to obtain the three-dimensional coordinates using the APAS motion analysis software. Gait patterns were assessed by measuring stifle, tibiotarsal joint angles and stifle joints angular velocity. Stifle and tibiotarsal joint functions were not affected by TPLO surgery, but stifle and tibiotarsal joint angles were changed, following CTWO surgery, compared with their preoperative values. The angular velocity patterns of CTWO were characterized by increased stifle joint extension velocity from the middle to end swing phase and decrease in the peak velocities (flexion) during swing phase. None of these changes was observed in the stance phase after the CTWO surgery. These kinematic results showed that dogs that underwent a CTWO procedure were more likely to have significantly hyperextended gait patterns of the swing phase postoperatively than the dogs that had a TPLO procedure for repair of a ruptured CrCL.

Differential diagnoses for canine bone disease are commonly based on radiography. However, scintigraphy is a nuclear scanning test to trace bone healing during stress fracture and osteomyelitis and thus can be used to probe the osseointegration process in vivo in the context of the dental implant. The purpose of this study was to explore the possibility of using noninvasive scintigraphy to probe the effect of platelet-rich plasma (PRP) to enhance osseointegration of the implant and to confirm the result with a parallel histological examination in adult beagle dogs. Two independent calcium phosphate-coated titanium screw implants 8 mm in length and 4 mm in diameter were inserted into each tibia in 4 dogs (4 implants/animal, total = 16). The PRP-treated group was deposited with 0.5 ml of PRP into the drill hole in the right tibia; the control group was instilled with 0.5 ml of saline into the drill hole in the left counterpart before titanium screw implantation. Radiography of the implanted tibias showed complete osseointegration but no osteomyelitis. No difference in the ossification of the peri-implant bone on the radiographs was observed between the two groups during the experimental period. However, the scintigraphic findings revealed obvious differences in bone uptake between the two groups. The higher bone uptake in the PRP-treated group significantly increased bone activity and faster bone regeneration compared to the control group (p < 0.05) at 4 weeks after implantation. The percentage of the bone-to-implant contact on histological examination in the PRP-treated group showed dense cortical bone formation in close contact with the metallic surface of the titanium implant (p < 0.05). Quantitative histological analysis correlated well with that of the scintigraphic evaluation as revealed by Pearson correlation analysis (r = 0.72, p < 0.05). Thus, scintigraphy is a sensitive and noninvasive method suitable for osseointegration of the implant in vivo.

No abstract

ABSTRACT. The aim of this study was to determine the cytotoxic and metabolic effects of iohexol on cultured bovine chondrocytes in clinical dose. Chondrocytes were exposed to 50%, 25% and 12.5% iohexol and 50% mannitol for 2 hours. Cell proliferation, apoptosis and necrosis were analyzed. Real time PCR was performed for aggrecan, collagen type I and II gene expression. Cells in alginate beads stimulated by interleukin-1β (IL-1β) were analyzed for cytotoxicity. MTT assay showed that 50% iohexol inhibited the proliferation of cells at 2 hours culture period. Propidium iodide results showed significantly higher dead cells at 50% iohexol compared to control, however PCR results revealed that chondrogenic gene were not affected. Cells in alginate beads stimulated with IL-1β showed significantly higher percentage of dead cells at 50% iohexol exposure (p<0.05). These results suggested that iohexol has a cytotoxicity on chondrocytes and this cytotoxic effect possibly increased in inflammatory joint diseases.