Bone fractures are a common form of skeletal injury affecting people of all ages. Fractured bones need to undergo a complex and coordinated process of healing. Here, you will find a comprehensive review of the stages of human bone healing and the intricate biological mechanisms involved, from the initial inflammatory response to the final remodeling phase. The stages of healing involve a complex interplay of cellular and molecular sequelae, ultimately resulting in the restoration of the bone’s structure and function. The doctors at clinica samaritana Alvarado will assist you in every stage of the bone healing process.
-
Inflammatory Phase
The initial response to a fracture is the inflammatory stage. Inflammation is a protective mechanism that initiates the healing process. It involves the release of various chemical inflammatory mediators, such as cytokines and growth factors, which recruit inflammatory cells to the fracture site and attract mesenchymal stem cells (MSCs) to initiate the next stage of healing.
2. 2. Hematoma Formation
Upon fracture, a hematoma or mass of clotted blood forms at the site due to the disruption of blood vessels. The hematoma serves as a scaffold for subsequent stages of bone healing. Neutrophils and macrophages play vital roles in removing debris and initiating tissue repair.
3. 3. Soft Callus & Granular Tissue Formation
During the formation of a soft callus, MSCs differentiate into chondroblasts and osteoblasts, forming a soft callus composed of fibrocartilage and collagen. This matrix bridges the fracture gap and simultaneously, the formation of granulation tissue, rich in blood vessels and fibroblasts, occurs. These blood vessels supply oxygen and nutrients necessary for bone healing.
4. 4. Hard Callus Formation & Endochondral Ossification
Osteoblasts are responsible for bone formation. They invade the soft callus and deposit new bone tissue. According to the doctors of clinica samaritana Alvarado, the soft callus gradually undergoes mineralization and transforms into a hard callus, composed of woven, immature bone. This process, known as endochondral ossification, involves the transformation of cartilage into bone. This hard callus provides structural stability and gradually bridges the fracture gap.
1. 5. Remodeling Phase
The remodeling phase is the last stage of bone healing. It is where the newly formed woven bone is reshaped into its mature and mechanically sound structure. Osteoclasts are another type of specialized bone cell, which resorb excess bone. Simultaneously, osteoblasts deposit new bone tissue is a process called bone modeling. The remodeling process can take several years, during which the bone eventually adapts to its mechanical demands.
Factors Affecting Bone Healing
Various factors negatively influence the stages of bone healing.
- Bone fracture type
- Location of the fracture
- Patient age
- Comorbidities
- Smoking
- Poor nutrition
- Impaired blood supply/non-union
- Surgical reduction of the fracture
- Infection
- Diabetes
Endnote
Orthopedic physicians working at the clinica samaritana Alvarado are responsible for treating each patient based on the type of fracture and overall physical condition. The factors mentioned above also come into play. The doctors may use different treatment options and tools, depending on the patient’s requirements. Sometimes, a bone growth stimulator is prescribed, which is a device that generates a gentle electric current and encourages bone growth.