Qualitative and quantitative scintigraphic imaging to predict fracture healing

Purpose: Evaluate the value of 24-hour postoperative quantitative bone scin tigraphy to identify devascularized fragments and predict delayed fracture bridging in canine clinical patients; to determine the effect of fracture t ype, fixation type, age, sex, and weight on fracture bridging and the quant itative scintigraphic ratios; and to evaluate the relationship between qual itative scintigraphic assessment and quantitative scintigraphic ratios. Met hods: Forty-two adult dogs, with diaphyseal long bone fractures treated wit h minimally invasive biological or invasive surgical techniques, were evalu ated with 24-hour postoperative bone scintigraphy and six and 12 week posto perative radiographs. Fractured bones were classified as simple, moderately multiple, or severely multiple. Bone scintigrams were qualitatively and qu antitatively analyzed. Radiographs were made at six and 12 weeks after the operation and graded as fracture gap(s) bridged or not bridged with bone op acity material. The data was evaluated statistically to determine the relat ionship between age, sex, and weight of the dogs, fracture type, fixation t ype, and results of scintigram analysis to fracture bridging at six and 12 weeks. Results: Fourteen of the 42 fractures were bridged at six weeks afte r the operation and 33 at 12 weeks. Prediction of fracture healing was not possible. There was not any statistical relationship of fracture type, fixa tion, sex, nor weight to bridged fractures or non-bridged fractures at six and 12 weeks. There was a trend toward more of the fractures with multiple fragments treated with minimally invasive biological techniques to be bridg ed by 12 weeks when compared to similar fractures treated with invasive tec hniques. The mean age of dogs with bridged fractures at six and 12 weeks wa s significantly lower than the mean age of dogs with non-bridged fractures at six and 12 weeks. Qualitative scintigraphic assessment scores were not s ignificantly related to the quantitative scintigraphic ratios or to fractur e bridging. Conclusions: Neither qualitative nor quantitative assessment of bone scintigrams 24 hours after the operation could be used to predict fra cture bridging at six or 12 weeks postoperatively.