Bone Healing and Inflammation: Principles of Fracture and Repair

Abstract

Bones comprise a significant percentage of human weight and have important physiologic and structural roles. Bone remodeling occurs when healthy bone is renewed to maintain bone strength and maintain calcium and phosphate homeostasis. It proceeds through four phases: (1) cell activation, (2) resorption, (3) reversal, and (4) bone formation. Bone healing, on the other hand, involves rebuilding bone following a fracture. There are two main types of bone healing, primary and secondary. Inflammation plays an integral role in both bone remodeling and healing. Therefore, a tightly regulated inflammatory response helps achieve these two processes, and levels of inflammation can have detrimental effects on bone healing. Other factors that significantly affect bone healing are inadequate blood supply, biomechanical instability, immunosuppression, and smoking. By understanding the different mechanisms of bone healing and the factors that affect them, we may have a better understanding of the underlying principles of bony fixation and thereby improve patient care.

The Osteoinductivity of Calcium Phosphate-Based Biomaterials: A Tight Interaction With Bone Healing

“…Bone remodeling is the final stage of bone healing and typically lasts for several months ( ElHawary et al, 2021 ). As a dynamic process, the irregular woven bone is reconstructed by bone resorption and osteogenesis process under mechanical stimulation and further developed as mature lamellar bone ( Frost, 2004 ; Loi et al, 2016 ; ElHawary et al, 2021 ). The crosstalk between osteoblasts and osteoclasts plays an important role in this phase.…”

Osteo-Immunomodulatory Role of Interleukin-4-Immobilized Plasma Immersion Ion Implantation Membranes for Bone Regeneration

“…Different macrophage phenotypes and an abnormal M1/M2 ratio have been linked to the development of numerous pathological conditions, including chronic venous leg ulcers, osteonecrosis, and atherosclerosis. Additionally, uncontrolled or prolonged local or systemic inflammation has long been known to impair bone healing or cause significant bone loss . Anti-inflammatory cytokines can be found in large quantities in M2 macrophages.…”

“…Additionally, uncontrolled or prolonged local or systemic inflammation has long been known to impair bone healing or cause significant bone loss. 13 Anti-inflammatory cytokines can be found in large quantities in M2 macrophages. These anti-inflammatory cytokines, such as IL1 receptor antagonist, IL4, IL10, IL11, and IL13, 14 function as the primary regulators of inflammation.…”

Guided Bone Regeneration with a Nitric‐Oxide Releasing Polymer Inducing Angiogenesis and Osteogenesis in Critical‐Sized Bone Defects

“…Subsequently, healing of the bone defect is incomplete. [24][25][26][27] Nitric oxide (NO) is an endogenous small molecule and free radical that participates in various biological processes, including inflammation, angiogenesis, wound healing, and protection from infection. [15,[28][29][30][31][32][33][34] In addition, several investigations have studied that endogenously and exogenously released NO plays a crucial role in physiology and pathology related to osteogenesis and bone regeneration.…”