To describe a modified technique for reinforced, free-form external skeletal fixation (rFF-ESF) of appendicular fractures in cats and identify factors associated with development of complications.
46 cats with fractures repaired with rFF-ESF at Angell Animal Medical Center between 2010 and 2019.
Medical records were reviewed for information on signalment, affected bone, fracture location and orientation, degree of comminution, severity (open vs closed), fixator type, number of fixation pins, use of an intramedullary pin (yes vs no), surgeon experience (staff surgeon vs surgical resident), anesthesia time, surgery time, perioperative antimicrobial administration, concurrent surgical procedures, intraoperative complications, postoperative alignment, whether fixator destabilization was performed, and time to complete fixator removal. Postoperative complications were recorded.
43 of the 46 (93%) cats had a successful outcome, with a median time to complete fixator removal of 8 weeks (range, 3 to 61 weeks). Twelve of the 46 (26%) cats had major (n = 3) or minor (9) complications. In univariable analyses, 4 factors were significantly associated with development of postoperative complications: body weight (OR for each 1-kg increase in weight, 1.8), tibial fracture (vs fracture of any other long bone; OR, 16), use of a type 2 fixator (vs a type 1 fixator; OR, 11), and use of destabilization (vs no destabilization; 7).
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that rFF-ESF can be successfully used to stabilize a variety of appendicular fractures in cats. Further studies are required to compare rFF-ESF with other fracture fixation methods.
To compare single and triplicate applanation tonometry values across previous intraocular pressure (IOP) studies in dogs.
116 ophthalmologically normal dogs.
Triplicate IOP readings (n = 1432) from studies evaluating effect of anesthetic protocols were analyzed to estimate a range of probable differences between averaged triplicate and first, averaged and lowest, and first and lowest IOPs. The decrease in variability with triplicate measurements and the magnitude of effects on statistical power were quantified.
The 2.5th to 97.5th interpercentile range for differences of averaged triplicate values minus first IOP readings was –3 to 2.7 mm Hg; for averaged minus lowest: 0 to 3.7 mm Hg; for first minus lowest: 0 to 5 mm Hg. The 95% prediction interval for differences in study group means (n = 160 groups, n = 5 to 11 eyes per group) based on averaged minus first measurements was –1.0 to 0.9 mm Hg with associated SDs reduced by 4% on average. Analysis of previous studies using averaged instead of first IOP values resulted in minimal decreases in SEs of 3–9% (0.03 to 0.09 mm Hg). Of 11 comparisons found significant with averaged data, 2 (18%) were found nonsignificant with first measurements. Of 96 comparisons found nonsignificant with averaged data, 3 (3%) were found significant with first measurements.
With applanation tonometry in ophthalmologically normal dogs, no clinically meaningful difference was found between the first, lowest, or averaged triplicate IOP measurements, but the first reading has a larger variance and hence will result in lower statistical power.