Efficacy of Multi-ion Doped Plasma Spray Nano-hydroxyapatite Coated Titanium Implants in Long Bone Fracture Repair in Dogs-Radiographical and Bone Markers Evaluation

Background: Fracture of long bones is a common orthopaedic condition noticed in dogs and its primary goal is to completely restore the function of the injured limb as early as possible. Osteo-conductivity of hydroxyapatite can be improved further by decreasing the particle size to nanometre range and incorporation of inorganic materials in hydroxyapatite can enhance osteoblast cell material interactions. Strontium, zinc, silver and fluorine are known to play an important role in the bone formation and also affect bone material characteristics such as crystallinity, degradation behaviour and mechanical properties. When doped with plasma spray nanohydroxyapatite, these multi-ions cause no harm to the physical environment during the degradation process of hydroxyapatite as these are nontoxic and play significant role in bone metabolism, growth and nourishment. Bone markers have tremendous potential as a rapid and sensitive method for assessing the response of the skeleton to medical or surgical interventions providing valuable information regarding bone turn over in animals. Hence, the current study was undertaken to evaluate the potential of multiion doped nano-hydroxyapatite coated intramedullary titanium implants in long bone fracture repair in dogs compared to the conventional intramedullary titanium implants through radiographical studies and evaluation of bone markers. Methods: Radiographical evaluation, sandwich ELISA kits developed by bioassay technology laboratory. Result: Plasma spray nano-hydroxyapatite coated titanium intramedullary implants have shown excellent osteo-conductivity when doped with multi-ions of strontium, zinc, silver and fluorine facilitating rapid osteoblastic activity and rapid bone turnover at the fracture site and complete fracture healing by 3rd week post-operatively as evidenced by radiographic scores and a peak BALP (Canine Bone Alkaline Phosphatase) values and early limb usage. Bone reabsorption and bone tissue remodelling due to osteoclastic action at the fracture site was quicker when the multi-ion doped nano-hydroxyapatite coated titanium intramedullary implants were used which is evidenced by the radiographic scores and highest CTX (Canine C-telopeptide of Type 1 Collagen) values indicating completion of fracture healing and near completion of bone tissue remodelling by 9th post-operative week in long bone fracture repair in dogs.