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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine the effects of transplantable substrates on canine chondrocytes grown in three-dimensional culture.

Animals

3 canine cadavers.

Procedure

Articular cartilage harvested from canine cadavers was used to obtain chondrocytes for primary culture. Subcultured chondrocytes were grown in agarose alone (AG), or in agarose on canine cancellous bone (CB), polypropylene mesh, or oxidized regenerated cellulose substrate. Cell proliferation, proteoglycan and glycosaminoglycan (GAG) production, and collagen production were assessed on days 3, 6, 10, 15 and 20.

Results

Chondrocytes from groups AG and CB proliferated and produced matrix over the entire 20-day study period. Group-CB chondrocytes had significantly more GAG than did chondrocytes of all other groups on days 6 (P = 0.0297) and 15 (P = 0.00272). Those of groups AG and CB contained significantly (P = 0.0235) more GAG on day 20. Chondrocytes of the polypropylene mesh group proliferated and produced matrix through day 10 in culture, but were no longer viable and had no matrix production on days 15 and 20. Regenerated cellulose appeared to be toxic to canine chondrocytes during all stages of in vitro three-dimensional culture.

Conclusions

Three-dimensional culture of canine chondrocytes in agarose appears to produce favorable results with respect to chondrocyte proliferation and matrix production. Canine CB appears to have beneficial effects with regard to early GAG synthesis. Polypropylene mesh and oxidized regenerated cellulose had detrimental effects on cellular proliferation and matrix production. (Am J Vet Res 1997;58:419–424)

Free access
in American Journal of Veterinary Research

Summary

Medical records of 6 Vietnamese pot-bellied pigs with articular fractures of the distal portion of the humerus were reviewed. Evaluation of the medical records did not reveal a sex predilection. All fractures were associated with minor traumatic episodes in young pigs. Of 6 fractures involving the humeral condyle, 4 involved the medial portion, 1 involved the lateral portion, and 1 was a Y-shaped fracture. Five of the pigs underwent surgical repair of the fracture, and all 5 did not have signs of lameness at follow-up evaluations (mean, 11 months). Of 4 pigs that had follow-up radiography, all had evidence of mild to moderate degenerative joint disease. Articular fractures of the distal portion of the humerus should be considered as a differential diagnosis in all Vietnamese pot-bellied pigs with forelimb lameness, even if the trauma sustained appeared mild. Surgical repair in Vietnamese pot-bellied pigs is straightforward, and excellent clinical results can be expected.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Corticocancellous bone graft was obtained from the caudoventral portion of the mandible of 8 dogs. The recipient site was an alveolar jugal and alveolar defect from vital root amputation of the mesiobuccal root of the maxillary fourth premolar. Anatomic observations of 20 canine cadavers indicated that guidelines for harvesting bone from the caudoventral portion of the mandible of dogs were the mesial aspect of the masseteric fossa, the distal aspect of the roots of the first mandibular molar, and the ventral aspect of the mandibular canal. The mean weight of corticocancellous bone harvested was 0.4 ± 0.1 g. Harvested corticocancellous bone was adequate to fill recipient sites measuring a mean volume of 105.0 ± 28.5 mm3. Histologic evaluation of the recipient site revealed progressive osseous integration of the bone-graft site during a mean follow-up period of 3.5 ± 1.9 months. There was normal bone healing of the donor site without adverse effects on the mandibular molars or neurovascular structures of the mandibular canal. Vital amputation sites receiving silver amalgam had evidence of plasmacytic/lymphocytic inflammation associated with residual silver amalgam in the bone-graft area. The caudoventral portion of the mandible may be used as a donor site for autogenous corticocancellous bone in periodontal surgery of dogs.

Free access
in American Journal of Veterinary Research

SUMMARY

An axial pattern flap that was based on the sternocleidomastoideus branches of the caudal auricular artery and vein was developed. Control flaps, which included ligation and division of the caudal auricular artery and vein, were similarly developed on the contralateral aspect of the neck. Mean survival of caudal auricular artery axial pattern flaps (85.2%), compared with control flaps (63.9%), was significantly different (P < 0.05). On the basis of results of this study, an axial pattern flap based on the sternocleidomastoideus branches of the caudal auricular artery and vein may be a source of skin for reconstructive procedures of the head and neck.

Free access
in American Journal of Veterinary Research

SUMMARY

Effects of temperature and storage time on canine bone-transfixation pin specimens were tested by comparing pin pull-out forces. A total of 16 femurs from 8 mature dogs were tested. Five nonthreaded Steinmann pins were placed through both cortices in the diaphysis of each femur. The femurs were then sectioned transversely between each pin, with a bonepin specimen placed evenly into each of 5 groups prior to biomechanical testing. Four bone-pin specimen groups were stored at −20 or −70 C for 14 or 28 days, while 1 specimen group was immediately tested. Pull-out forces for frozen groups were compared with pull-out forces for the fresh group.

Using two-way anova, there was no statistical difference in mean axial-extraction forces among bonepin specimens in any of the tested groups. It is concluded that acute pin pull-out forces are not significantly affected by freezing temperature or time. However, specimens stored at −20 C for as few as 14 days had a trend for increased pull-out forces, compared with freshly harvested specimens. Therefore, the authors recommend storage of bone-pin specimens at −70 C when possible.

Free access
in American Journal of Veterinary Research

Summary

Eight dogs were determined to be orthopedically normal on the basis of prelavage physical examination, stifle radiography, synovial fluid analysis, and force plate analysis (peak vertical force normalized for body weight, and time on the force plate). Each dog had 1 stifle randomly assigned to be lavaged with 100 ml of a commercially available 0.05% (w/v) chlorhexidine diacetate solution, and the contralateral stifle was lavaged with lactated Ringer’s solution.

Difference was not detected between the chlorhexidine diacetate and lactated Ringer’s solution-treated joints, with regard to results of synovial fluid analysis and clinical lameness evaluations on days 4 and 8 after lavage. Chlorhexidine diacetate caused a more intense synovitis than did lactated Ringer’s solution, as determined by histologic evaluation of synovial membrane specimens after necropsy on day 8; however, a difference in the intensity of toluidine blue staining of articular cartilage was not found between treatments. Chlorhexidine diacetate, as a 0.05% (w/v) solution, cannot be recommended as a joint lavage fluid until the duration of inflammatory changes in the synovial membrane are determined or until the chemical constituents of chlorhexidine diacetate causing the synovitis can be identified and removed.

Free access
in American Journal of Veterinary Research

SUMMARY

Transcutaneous oxygen monitoring is commonly used in human beings to assess skin viability. Little attention has been directed toward the use of transcutenaous carbon dioxide (PCO2-TC ) monitoring for the same purpose. The application of PCO2-TC monitoring for evaluating skin viability in dogs was investigated.

The changes in PCO2-TC and local power reference (LPR) values were measured from 16 skin flaps created along the lateral hemithoraces of 4 dogs. Transcutaneous PPCO2 and LPR values were serially recorded from the base and apex of each flap for 12 hours. A single measurement was obtained from each flap base and apex 24 hours after surgery. Arterial blood gas analyses were obtained to compare central PCO2 values with peripheral skin PCO2 values. The flaps were observed for 4 days and then harvested for histologic examination. Full-thickness skin biopsy specimens were obtained 24 hours after surgery and when the flaps were harvested to evaluate the viability of the apex and base of the flaps. A subjective grade was assigned to all skin biopsy specimens during histologic examination.

For all measurements, a significant difference was found between the PCO2-TC values for apices and bases of the flaps. The mean PCO2-TC for all bases was 52.66 mm of Hg ± 2.24 (SEM), and the mean PCO2-TC for all apices was 106.4 mm of Hg ± 2.44. The regional carbon dioxide index (apex PCO2-TC /base PCO2-TC ) was 2.02.

A significant difference was not found between the LPR values for bases and apices. The mean lpr for all bases was 253.23 mW ± 4.06, and the mean LPR for all apices was 243.53 mW ± 4.49.

A signficant difference was found between the histologic grades assigned to the collective bases and apices 4 days after creation of the flaps. A difference was not found between the collective bases and apices 24 hours after flap creation. On the basis of our findings, transcutaneous carbon dioxide monitoring is a useful method of evaluating skin viability in dogs.

Free access
in American Journal of Veterinary Research