Description, Outcome, and Complications Associated with Reinforced, Free-Form External Skeletal Fixation in 51 Cats

Introduction: Free-form external skeletal fixators (FF-ESF) can be applied for fracture fixation by anchoring fixation pins in polymethylmethacrylate (PMMA). These fixation pins can be left long and lashed together into a frame prior to PMMA application, such that these pins span the entire length of the PMMA column, thus providing additional tensile strength. The purpose of this study was to describe this modified approach to reinforce FF-ESF (rFF-ESF) for fracture fixation in cats and to identify risk factors associated with complications.

Materials and Methods: Medical records of cats with fractures repaired with rFF-ESF at Angell Animal Medical Center between 2010 and 2019 were reviewed. Information gathered from medical records included signalment, fracture description, fracture fixation, and postoperative follow-up. Postoperative complications were also recorded.

Results: A total of 51 cats with fractures surgically stabilized with rFF-ESF were identified between 2010 and 2019. Successful outcome was reached in 94% of cases. Total complication rate was 27%. Minor and major complications comprised 78 and 22% of total complications, respectively. For every 1-unit increase in weight (kg), BCS (score), age (year), the odds of having a complication increased by 70, 90, and 30%, respectively. Being spayed/neutered, Type-II external fixators, and destabilization increased odds of complication by 5x, 5x, and 4x, respectively. Tibial fractures also had an increased risk of complications.

Discussion/Conclusion: Reinforced free-form external skeletal fixation is a reasonable alternative to traditional methods of external skeletal fixation with respect to outcome and postoperative complication rate.

Acknowledgment: There was no proprietary interest nor funding provided for this project.