Intramedullary Nailing of Diaphyseal Fractures

Kenneth A. Johnson, MVSc, PhD, FACVSc, DACVS, DECVS

Some key considerations in the planning of fracture treatment are the feasibility of regaining normal anatomic alignment or reduction, the biomechanics of the fracture stabilization method, and the impact of these two interventions on the preexisting fracture biology and its healing response. Intramedullary nailing has been used for the stabilization of selected long bone fractures, with varying degrees of success, in humans and animals for approximately 80 years. During this period, the patient outcomes have improved considerably due to improvements in implant design and surgical techniques.

Sisk and colleagues have reviewed the modern evolution and concepts of biomechanical stability of intramedullary nailing, with a focus on innovations and improvements in design of intramedullary nailing.[1] Some of the more important improvements in biomechanical performance of interlocking nailing of diaphyseal fractures have come from the following advances: (1) achievement of adequate nail diameter and stiffness to counteract bending forces, (2) proximal and distal locking with angle-stable bolts to control torsional and axial loads, and (3) anatomical precontouring (prebending) of interlocking nails to match the three-dimensional geometry of the marrow cavity. Consideration of research into long bone fracture repair in humans and animals in this comparative manner is very much in keeping with the underlying philosophy of Veterinary and Comparative Orthopaedics and Traumatology (VCOT). Some interesting figures reported by Sisk and colleagues are that the publication rate of intramedullary nailing papers in human medicine rose from approximately 100 per year in 2003 up to 600 per year in 2023.[1] By contrast, veterinary publications on this topic have lagged behind, fluctuating around 10 papers per year, over the same 20-year period.[1]

Both anatomical differences between animal species and the large range of body sizes (especially in the dog) can create difficulties in having a nail that will fit into the medullary canal of the femur, tibial, or humerus of some veterinary patients. Surprisingly, the successful miniaturization of intramedullary nails suitable for mice and rats (RISystems AG, Landquart, Switzerland) used for bone-healing research shows that much greater development of interlocking nails for animals is possible,[2] and indeed much needed in future.

Kenneth A Johnson

Editor-in-Chief, Veterinary and Comparative Orthopaedic and Traumatology

Publication History

Article published online:
11 November 2024

• References

• 1 Sisk MR, Yang LC, Paul KD. et al. Biomechanical principles of intramedullary nails in veterinary and human medicine. Vet Comp Orthop Traumatol 2024; 37 (06) 257-262
• 2 Schmitz N, Timmen M, Kostka K. et al. A novel MRI compatible mouse fracture model to characterize and monitor bone regeneration and tissue composition. Sci Rep 2020; 10 (01) 16238