Safety pin tie-in external skeletal fixation in pediatric feline and canine humeral/femoral fractures: 3 cases.

Three animals (1 dog and 2 cats), all weighing < 3 kg and aged 4 to 7 mo, were treated for femoral or humeral fractures using the "safety pin tie-in" (SPTI), a proximal transverse-pin-free Type Ia intramedullary pin tie-in external skeletal fixator. Clinical assessment, radiographic follow-up, and owner-reported outcomes were evaluated. Only minor complications after surgery were observed, and radiographic interpretation of healing was achieved in all cases. For all animals, weight-bearing function was regained soon after surgery, limb function was classified as full (Cases 1 and 3) or acceptable (Case 2), and owner satisfaction was excellent. Subjective assessment of long-term outcomes revealed no or only minimal disability, with a Liverpool Osteoarthritis in Dogs (LOAD) score of 5/52 for the dog and Feline Musculoskeletal Pain Index short form (FMPI-sf) scores of 1/28 and 0/28 for the cats. The SPTI, with its simplified design, appeared to provide adequate biomechanical stability in pediatric cases without the need for a proximal transfixing pin. Key clinical message: By minimizing surgical trauma, the technique described herein may represent a practical alternative to elastic plate fixation in selected lightweight pediatric animals, though further studies are needed to confirm these findings.