Evaluation of composite resin materials for maxillomandibular fixation in cats for treatment of jaw fractures and temporomandibular joint luxations.

OBJECTIVE: To identify a method of composite application for maxillomandibular fixation (MMF) in cats that ensures the material will remain bonded during convalescence but be easy to remove with a low complication rate. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Feline cadavers (n=88). METHODS: MMF was applied using composite to 4 groups of 22 feline cadaver heads each. The protocols were: group CR: acid etch and composite resin; group CR+: acid etch, bonding agent, and composite resin; group FR50: partial surface acid etch and flowable composite resin; group FR100: complete surface acid etch and flowable composite resin. Removal time and complication rate were noted. Load to failure was determined by tensile loading. RESULTS: Load to failure was similar for groups CR and CR+ and for groups FR50 and FR100; however, load to failure for groups FR50 and FR100 was higher than groups CR and CR+ (P<.01). Time for material removal for group FR100 was longer (P<.01) and the complication rate was higher (P<.01) compared with the groups CR, CR+, and FR50, with no significant differences in removal times and complication rate between the latter groups. The most frequent complication during material removal in group FR100 was crown fracture. CONCLUSIONS: Partial coronal surface acid etch before use of flowable composite maintained a strong bond, yet resulted in easy material removal with a low complication rate.

Evaluation of intra- and interobserver variability and repeatability of tibial plateau angle measurements with digital radiography using a novel digital radiographic program.

OBJECTIVE: To compare the intra- and interobserver variability occurring when observers with differing experience levels measure tibial plateau angles (TPAs) with a novel digital radiographic projection program (tibial plateau leveling osteotomy [TPLO] planning program), the Kodak Picture Archiving and Communications System (PACS), and standard sized printed films (SF). STUDY DESIGN: Cross-sectional study. SAMPLE POPULATION: Dogs (n=36) with cranial cruciate ligament (CCL) rupture that had a TPLO. METHODS: Six observers, divided into 3 equal groups based on experience level, measured TPA on 36 digitally captured radiographic images of tibiae of dogs clinically affected with CCL rupture. Each observer used 3 methods of measuring TPA and repeated the measurements 3 times with each method. The intra- and interobserver variability was compared using the coefficient of variation. RESULTS: Averaged over all replications and images, there was no significant difference (P>.05) in the average variability occurring with each method for all but 1 observer. There was no effect of experience level on measurement variability; however, interobserver variability was significantly less with measurements made with the PACS and TPLO planning program compared with measurements made from SF (P<.05). CONCLUSIONS: Repeated measurements of TPA made using digital images and computer-based measurement programs were significantly less variable between observers than those made from images printed on standard radiographic films. CLINICAL RELEVANCE: Digital radiography and computer-based measurement programs are effective for determining the TPA, allowing less variability in measurements compared with SF. The ability to manipulate the image may allow better identification of anatomic landmarks.

Clinical applications of demineralized bone matrix: a retrospective and case-matched study of seventy-five dogs.

OBJECTIVES: To evaluate the outcome in dogs treated with demineralized bone matrix (DBM) as an adjunct to orthopedic procedures. STUDY DESIGN: Retrospective and case-match study. ANIMALS: Dogs (n=75). METHODS: Medical records (1999-2006) and radiographs of dogs that had orthopedic procedures (comminuted fractures, tibial plateau leveling osteotomy [TPLO] where correction for tibial rotation created an osteotomy gap, arthrodeses, open corrective osteotomies) where DBM was used were reviewed for signalment, quantity of DBM implanted, duration of exercise restriction, radiographic healing, and complications. Dogs that had TPLO and correction of tibial torsion (n=15), or arthrodesis (n=16) were compared with case-matched controls. Data were analyzed using Kruskal-Wallis test, ANOVA, Tukey's HSD test, and logistic regression analysis. RESULTS: Mean (+/-SD) healing time for orthopedic surgeries with DBM augmentation were 15+/-6.97 (weeks) and complication rate was 19% (14 dogs). Dogs with a TPLO gap filled with DBM were allowed to return to normal exercise 2 weeks earlier than dogs with a well-apposed TPLO site. Radiographic healing, duration of exercise restriction, and timing of destabilization were similar in dogs undergoing carpal and tarsal arthrodesis whether they received DBM, autogenous graft, or both. CONCLUSIONS: DBM can be used to treat uncomplicated bone defects associated with comminuted fracture repairs, open osteotomies, and arthrodeses in dogs. Under these circumstances, clinicians might expect similar clinical outcomes without the possibility of side effects associated with the harvest of autogenous cancellous bone. CLINICAL RELEVANCE: DBM is safe for use in dogs.