Delayed union, malunion, and nonunion are serious complications in the healing of fractures. Predicting the risk of nonunion before or after surgery is challenging.

To compare the most prevalent predictive scores of nonunion used in clinical practice to determine the most accurate score for predicting nonunion.

We collected data from patients with tibial shaft fractures undergoing surgery from January 2016 to December 2020 in three different trauma hospitals. In this retrospective multicenter study, we considered only fractures treated with intramedullary nailing. We calculated the tibia FRACTure prediction healING days (FRACTING) score, Nonunion Risk Determination score, and Leeds-Genoa Nonunion Index (LEG-NUI) score at the time of definitive fixation.

Of the 130 patients enrolled, 89 (68.4%) healed within 9 months and were classified as union. The remaining patients (n = 41, 31.5%) healed after more than 9 months or underwent other surgical procedures and were classified as nonunion. After calculation of the three scores, LEG-NUI and FRACTING were the most accurate at predicting healing.

LEG-NUI and FRACTING showed the best performances by accurately predicting union and nonunion.

To determine the levels of agreement among first- and second-year veterinary students and experienced anesthesiologists in assessing postoperative pain in dogs from video-recordings.

Cross-sectional study.

Twenty-seven veterinary students, five anesthesiologists and 13 canine clinical patients.

Prior to their enrolment in a core anesthesia course, veterinary students volunteered to watch 13 90 second videos of dogs. Dogs were hospitalized in an intensive care unit after a variety of surgical procedures. Students were asked to score the level of the dogs' pain using the Dynamic Interactive Visual Analog Scale and the Short Form of the Glasgow Composite-Measure Pain Scale. The same videotapes were scored by five board-certified anesthesiologists. The differences and agreement between the ratings of anesthesiologists and students, and first- and second-year students were determined with Mann-Whitney U-tests and Fleiss' or Cohen's kappa, respectively.

Pain scores assigned by students and anesthesiologists differed significantly (p < 0.01). Students assigned higher pain scores to dogs that were given low pain scores by anesthesiologists, and lower pain scores to dogs deemed to be in more pain by anesthesiologists. On average, students assigned higher scores on both scales.

Veterinary students early in their training assigned pain scores to dogs that differed from scores assigned by experienced anesthesiologists.

Long-term systemic use of corticosteroids causes osteoporosis and increased risk of fracture. However, the effect of short-term use of corticosteroids on bone healing is not well defined. The aim of the present study was to test the influence of short-term systemic corticosteroid therapy on bone healing. Standardized bone defects (2 mm diameter) were formed in the middle of the femur in 40 male rats. Rats were divided into two groups; control group (n = 20) and prednisone-treated group (n = 20). Subcutaneous injection of either sterile normal saline (control) or 0.020 mg kg(-1) dose of prednisone was administered just before surgery and thereafter daily for 3 days. Histopathological cross sections were taken 1, 2, 3 and 4 weeks after surgery. There was no statistically significant difference between the prednisone group and the control group. No inhibitory effects were seen following short-term corticosteroid treatment.

In laboratory animals many models of inflammation have been developed for preclinical evaluation of the pharmacological profiles of nonsteroidal anti-inflammatory drugs (NSAIDs). In contrast, in species of veterinary interest, including the cat, NSAIDs have been studied mainly using dose-titration or dose-confirmation studies in clinical subjects. This is due to the scarcity of appropriate animal models and to the associated lack of quantitative validated endpoints describing the magnitude and time course of drug response. Determination of pharmacokinetic/pharmacodynamic (PK/PD) relationships provides a powerful approach for the selection of effective and safe dosage regimens. In this study, a paw inflammation model in the cat was developed for the preclinical evaluation of NSAIDs using PK/PD modelling. Subcutaneous injection of 500 mg kaolin in the paw produced a well-defined and reproducible inflammatory response that lasted 4-5 days. Several endpoints were assessed for their clinical relevance and for their metrological performance (accuracy and reproducibility). Body temperature, lameness scoring, locomotion tests and possibly skin temperature were the most appropriate endpoints for testing the antipyretic, analgesic and anti-inflammatory effects of NSAIDs in the cat.

We studied the effects of short-term therapy with methylprednisolone and indomethacin on healing of intramedullary pinned osteotomies of the femur in rats. When the osteotomy was complete and healing occurred under unstable conditions with callus formation, indomethacin inhibited healing when estimated by mechanical tests of bending moment, energy expenditure before refracture, and bending rigidity 6 weeks after surgery. No inhibitory effects were seen following corticosteroid treatment. When the osteotomy was incomplete and healing occurred under stable conditions, similar tendencies were observed. Thus, short-term medication with indomethacin inhibits fracture healing. This was not the case with short-term methylprednisolone.

Randomized placebo-controlled crossover studies were carried out in dogs to evaluate how two non-steroidal anti-inflammatory drugs (NSAID) might modulate an acute post-traumatic inflammatory reaction. Two "identical" surgical interventions were performed on the forelimbs of each animal with an interval of 28 days, to enable a paired comparison of the inflammatory signs and the wound/bone healing processes. At one operation 8 dogs received 300 mg phenylbutazone twice daily for 8 days starting on the day before surgery, and at the other operation matching placebo tablets were given. In a similar placebo-controlled trial another group of 8 dogs received 5 mg indomethacin twice daily. With phenylbutazone the post-operative swelling was not significantly reduced compared to placebo, but there was less pain and limping. With indomethacin the swelling was somewhat reduced, but there was no consistent difference to placebo in the pain and limping assessments. None of the drugs appeared to distinctly effect the wound or fracture healing, as evaluated by clinical inspection, comparison of radiographs and comparison of bone sections from the sites of surgery. It proved difficult to select an appropriate dosage of indomethacin due to its high potential to induce GI ulceration and bleeding in dogs. In this experimental surgical model with an acute inflammation, neither phenylbutazone nor indomethacin showed impressive anti-inflammatory or analgesic properties. In the same model paracetamol has proved to significantly and more efficiently, reduce both swelling and pain without any noticeable adverse effects, and appears to be a better alternative than the two presently tested NSAID.

Randomized placebo-controlled crossover studies were carried out in dogs to evaluate how two non-steroidal anti-inflammatory drugs (NSAID) might modulate an acute post-traumatic inflammatory reaction. Two "identical" surgical interventions were performed on the forelimbs of each animal with an interval of 28 days, to enable a paired comparison of the inflammatory signs and the wound/bone healing processes. At one operation 8 dogs received 300 mg phenylbutazone twice daily for 8 days starting on the day before surgery, and at the other operation matching placebo tablets were given. In a similar placebo-controlled trial another group of 8 dogs received 5 mg indomethacin twice daily. With phenylbutazone the post-operative swelling was not significantly reduced compared to placebo, but there was less pain and limping. With indomethacin the swelling was somewhat reduced, but there was no consistent difference to placebo in the pain and limping assessments. None of the drugs appeared to distinctly effect the wound or fracture healing, as evaluated by clinical inspection, comparison of radiographs and comparison of bone sections from the sites of surgery. It proved difficult to select an appropriate dosage of indomethacin due to its high potential to induce GI ulceration and bleeding in dogs. In this experimental surgical model with an acute inflammation, neither phenylbutazone nor indomethacin showed impressive anti-inflammatory or analgesic properties. In the same model paracetamol has proved to significantly and more efficiently, reduce both swelling and pain without any noticeable adverse effects, and appears to be a better alternative than the two presently tested NSAID.

In placebo-controlled cross-over trials in dogs, two 'identical' operations were performed on the forelimbs of each animal with an interval of 28 days, to evaluate how daily doses of 1.5 g paracetamol, 1.5 g acetylsalicylic acid (ASA) and 0.5 g ASA might modulate an acute post-operative inflammatory reaction. On the third post-operative day the reductions in swelling compared with placebo averaged 33% with 1.5 g paracetamol (P = 0.02), 24% with 1.5 g ASA (P = 0.03) and 15% with 0.5 g ASA (P = 0.18); while the reductions in pain estimates averaged 47% with 1.5 g paracetamol (P = 0.01), 32% with 1.5 g ASA (P = 0.07) and 28% with 0.5 g ASA (P = 0.21). There were no clinical signs of adverse drug effects, such as vomiting, haematochezia, cyanosis or depression. The results disagree with the traditional view that paracetamol has little or no anti-inflammatory effect, and demonstrate that paracetamol may reduce an acute inflammatory reaction, at least as efficiently as ASA. The potential pro-inflammatory effect of ASA in low doses is discussed. It is concluded that paracetamol appears to be a valuable drug against post-operative or post-traumatic sequelae in the veterinary as well as in the human clinic.