Histologic assessment of age-related changes in the temporomandibular joints of horses.

OBJECTIVE: To describe histologic changes in the temporomandibular joints (TMJs) of horses of various ages. SAMPLE: 22 TMJs from cadavers of 11 horses. PROCEDURES: Horses were categorized into 3 age groups (group 1, 2 to 10 years old [n = 3]; group 2, 11 to 20 years old [3]; and group 3, > 20 years old [5]). Each TMJ was sectioned into 5-mm slices, preserved in formalin, decalcified in formic acid, and routinely processed for histologic analysis. Joints were systematically assessed by use of previously described methods. Multilevel mixed-effects models were used to examine the data. RESULTS: The number of changes was significantly fewer and degree of changes was significantly less within the TMJs of group 1 horses, compared with those of group 3 horses. Comparison among groups revealed that the combination of temporal and mandibular scores for group 1 was significantly lower than for groups 2 or 3. Disk score did not differ significantly between groups 1 and 2, but disk scores of groups 1 and 2 were significantly lower than the disk score of group 3. CONCLUSIONS AND CLINICAL RELEVANCE: The assessed lesions were associated with osteoarthritis, and they accumulated in the TMJs as horses aged. In the absence of signs of pain manifested as changes in mastication, behavior, or performance, it would be difficult to determine the point at which accrued pathological changes represented the onset of clinically important osteoarthritis of the TMJs.

In vitro assessment of bacterial translocation during needle insertion through inoculated culture media as a model of arthrocentesis through cellulitic tissue.

OBJECTIVE: To determine by use of an in vitro model the potential for translocating sufficient numbers of bacteria into a joint during arthrocentesis through cellulitic tissue to cause sepsis. SAMPLE: Culture media containing 4 concentrations of Staphylococcus aureus and needles of 3 sizes. PROCEDURES: Needles (22, 20, and 19 gauge) were inserted through Mueller-Hinton agar that contained known concentrations of S aureus (10(3),10(4),10(5), and 10(6) CFUs/mL). After a needle exited through the medium, any agar plug within the needle bore was ejected into a sterile syringe and the contaminated portion of the needle was harvested. Sterile saline (0.9% NaCl) solution was used to emulsify the agar plug and wash the contaminated portion of the needle. The resulting solution was cultured to determine the number of bacterial CFUs that could be deposited into a joint during arthrocentesis through contaminated tissue. RESULTS: Needle gauge and bacterial concentration were both associated with the number of bacterial CFUs deposited after insertion through contaminated agar. Although all needle sizes were capable of bacterial translocation sufficient to cause septic arthritis, ORs for 20- and 22-gauge needles translocating > 33 CFUs of S aureus were significantly higher than the OR for a 19-gauge needle. The ORs for 20- or 22-gauge needles translocating > 33 CFUs of S aureus (the minimum population of S aureus known to cause joint sepsis) were 0.22. CONCLUSIONS AND CLINICAL RELEVANCE: Results for this in vitro model indicated that caution should be used when performing arthrocentesis through cellulitic tissue.

Management and long-term outcome of partial glossectomy in 2 horses.

Records were reviewed for 2 horses with partial glossectomy, 1 traumatic and 1 elective. According to long-term follow-up by telephone, both horses had recovered well, experiencing only temporary difficulty while eating, and went on to be ridden successfully using mouth bits. Partial glossectomy, therefore, had a favorable prognosis in 2 performance horses.

Gestion et résultat à long terme de la glossectomie partielle chez 2 chevaux. Les dossiers ont été examinés pour 2 chevaux ayant subi une glossectomie partielle, 1 étant une glossectomie traumatique et 1 étant une glossectomie non urgente. Selon le suivi à long terme par téléphone, les deux chevaux se sont bien rétablis, ont éprouvé seulement une difficulté temporaire à manger et ont ensuite pu être montés avec succès en utilisant des mors. Par conséquent, une glossectomie partielle a présenté un pronostic favorable chez 2 chevaux de performance.(Traduit par Isabelle Vallières).