Objectives: To quantitatively describe the intramedullary arterial supply of the adult feline tibia and determine if the arterial supply is significantly different from that of adult small dogs.
Methods: Cadaveric feline and canine pelvic limbs were obtained to prospectively investigate the intramedullary arterial supply of the tibia. A microvascular injection and modified Spalteholz bone clearing technique were used to characterize and quantify the intramedullary arterial supply of the tibia. Statistical comparisons were made between cats and dogs for the percentage of intramedullary arterial supply (arterial density) and the diameter of the nutrient artery.
Results: No significant difference was observed in the intramedullary arterial density between dog and cat tibiae. The feline nutrient artery diameter (0.55 ± 0.1 mm) was significantly greater than the canine nutrient artery (0.30 ± 0.04 mm) in the distal section of bone. Dogs subjectively had a greater number of branching vessels in the distal and mid-diaphyseal sections of bone when compared to cats.
Clinical significance: Delayed fracture healing in the feline tibia does not appear to be associated with a lack of intramedullary arterial supply. A lack of diffuse arborization of the arterial supply to the middle and distal feline tibia may explain, at least in part, why feline tibial delayed or nonunions may be more common than in canine tibial fractures.