Long-term prognosis of metacarpal and metatarsal fractures in dogs. A retrospective analysis of medical histories in 100 re-evaluated patients.

OBJECTIVES Lameness after metacarpal and metatarsal fractures in dogs is reported to occur with an incidence of 18% to 70%. On the basis of long-term results, the prognosis of these injuries was re-evaluated retrospectively. METHODS Medical records of 100 dogs with complete clinical and radiographic follow-up examinations after an average of four years (4 months - 14 years) were evaluated. According to their treatment, patients were allocated to three groups (Group 1=conservative, Group 2=surgical, Group 3=combined). Assessment included complications during the healing period and the final radiographic and functional outcome, which was statistically compared for differences between groups (Fisher exact test, exact Wilcoxon-Mann-Whitney test). Further, risk factors for each bone were analyzed (stepwise, multiple logistic regression model). In 15 dogs, kinetic data (relative stance phase, peak vertical force and impulse) were investigated by computed gait analysis. RESULTS Complications were observed in 11 of 67 (16%) conservatively, in three of 25 (12%) surgically, and in three of eight (37%) conservatively and surgically treated dogs. Overall frequency of lameness evaluated by visual clinical assessment was three percent. Frequency of osteoarthritis and nonunion was also low, accounting for three percent and one percent respectively, although healing of mainly single-bone fractures resulted in malunions in 14% radiographically. Synostoses were found in 19% of patients, and significantly more frequent in surgically treated dogs. A higher risk of complications was identified for metatarsal compared to metacarpal fractures. Further, an increased risk for complications was detected for a higher degree of displacement and instability. CLINICAL SIGNIFICANCE According to the long-term results found in this study, the prognosis for metacarpal and metatarsal fractures is better than reported in the literature to date. With the reservation that more severe injuries are generally treated surgically, and these fractures more frequently developed synostosis, no significant difference could be detected between conservative and surgical treatment.