Clinical Feasibility of an Octacalcium Phosphate/Gelatin Composite as a Bone Substitute in Open-Wedge Distal Tuberosity Tibial Osteotomy

Octacalcium phosphate/gelatin (OCP/Gel) composite is a biomimetic calcium phosphate material we developed to enhance osteoconduction and physiological bone remodeling.OCP/Gel has the potential to support early metaphyseal bone regeneration by facilitating the gradual conversion to hydroxyapatite and promoting biological integration.Open-wedge distal tuberosity tibial osteotomy (OWDTO), while preserving the tibial tuberosity, creates a large metaphyseal gap that requires reliable bone healing.We report a case series evaluating the clinical feasibility of OCP/Gel as a graft material in OWDTO.Ten consecutive patients with varus knee osteoarthritis underwent OWDTO with medial -tricalcium phosphate (-TCP) and lateral OCP/Gel implantation and were followed for a minimum of six months.Radiographs demonstrated progressive bone union in all cases without delayed union or correction loss.No material-related adverse events were observed, except for one superficial infection.In selected cases, computed tomography and magnetic resonance imaging revealed peripheral ossification and gradual graft resorption with structural remodeling, indicating active biological integration.These findings suggest that OCP/Gel may serve as a biologically active graft option for promoting early metaphyseal bone healing after OWDTO.