Temporal response of an injectable calcium phosphate material in a critical size defect

• Published in: Journal of orthopaedic surgery and research 2021-08, Vol.16 (1), p.496-496, Article 496
• Main Authors: Landeck, Jacob T, Walsh, William R, Oliver, Rema A, Wang, Tian, Gordon, Mallory R, Ahn, Edward, White, Colin D
• Format: Article
• Language: English
• Subjects: Animals; Body temperature; Bone grafts; Bone growth; Bone healing; Bone Regeneration; Bone resorption; Bone Substitutes; Bone surgery; Calcium phosphate; Calcium phosphates; Calcium Phosphates - administration & dosage; Calcium Phosphates - chemistry; Cancellous bone; Cement; Computed tomography; Defect; Defects; Femur; Femur - physiology; Hyaluronic acid; Mechanical properties; Minimally invasive surgery; Orthopedics; Osteoconduction; Osteogenesis; Rabbit; Rabbits; Skin & tissue grafts; Surgery; Tomography; Trauma; X-Ray Microtomography
• ISSN: 1749-799X; 1749-799X
• DOI: 10.1186/s13018-021-02651-8

Calcium phosphate-based bone graft substitutes are used to facilitate healing in bony defects caused by trauma or created during surgery. Here, we present an injectable calcium phosphate-based bone void filler that has been purposefully formulated with hyaluronic acid to offer a longer working time for ease of injection into bony defects that are difficult to access during minimally invasive surgery. The bone substitute material deliverability and physical properties were characterized, and in vivo response was evaluated in a critical size distal femur defect in skeletally mature rabbits to 26 weeks. The interface with the host bone, implant degradation, and resorption were assessed with time. The calcium phosphate bone substitute material could be injected as a paste within the working time window of 7-18 min, and then self-cured at body temperature within 10 min. The material reached a maximum ultimate compressive strength of 8.20 ± 0.95 MPa, similar to trabecular bone. The material was found to be biocompatible and osteoconductive in vivo out to 26 weeks, with new bone formation and normal bone architecture observed at 6 weeks, as demonstrated by histological evaluation, microcomputed tomography, and radiographic evaluation. These findings show that the material properties and performance are well suited for minimally invasive percutaneous delivery applications.