> ## Content Index > Fetch the complete content index at: https://www.theplasticsfella.com/llms.txt > Use this file to discover other available public pages before exploring further. # Bone Healing - URL: https://www.theplasticsfella.com/bone-healing/ - Published: 2022-06-06T15:33:31.000Z - Updated: 2024-06-27T20:34:59.000Z - Description: Bone healing can be classified as primary or secondary. It undergoes haematoma formation, inflammation, proliferation, callus and remodelling. - Author: PlasticsFella - Tags: Core Principles ‌ ‌ 👇 ****In this Article** [5 Key Points](https://www.theplasticsfella.com/bone-healing/#bone-healing) [Bone Anatomy](https://www.theplasticsfella.com/bone-healing/#bone-healing-anatomy) [Types of Bone Healing](https://www.theplasticsfella.com/bone-healing/#types-of-bone-healing) [Stages of Bone Healing](https://www.theplasticsfella.com/bone-healing/#stages-of-bone-healing) [Complications of Bone Healing](https://www.theplasticsfella.com/bone-healing/#complications-of-bone-healing) [Flashcards](https://www.theplasticsfella.com/bone-healing/#flashcards) --- ## Bone Healing 💛 ****5 Key Points** ****1.** Bone has an inner cancellous layer and an outer cortical layer. ****2\.** Has periosteal, endosteal, epiphyseal and apophyseal blood supply. ****3.** Healing can be primary (no callus) or secondary (callus formation) ****4.** Stages are hematoma, inflammation, proliferation, callus, remodel. ****5.** Complications include non-union, malunion, & delayed union. --- ## Bone Healing Anatomy Bone is derived from ****mesenchyme** through ****intramembranous** and ****endochondral** ossification to give an outer ****cortical** layer and an inner ****cancellous** layer. ### ### Bone Structure Bones have an outer cortical layer and an inner cancellous layer. Each structure has a specific purpose, as detailed below: - **Cortical**: columnar structure and concentric layers connected by longitudinal Haversian canals (central blood vessel) and transverse Volkmann canals (nutrient vessels). - **Cancellous**: loosely woven trabeculae of organic and inorganic bone. These structures are both used in [bone grafting.](https://www.theplasticsfella.com/bone-grafts/#autologous-bone-autografts) 🤓 ****Fun Fact:** cartilage is the precursor for bone formation endochondral ossification. ### Bone Blood Supply Bone receives more than one type of blood supply depending on its location and origin/insertions. The important vascular vessels are: - Periosteal - Apophyseal - Endosteal (nutrient supply to the medullary cavity) - Epiphyseal (growth plates) 🤓 ****Memory hook for Bone Blood Supply:** ****PEACE**· ****P**eriosteal· ****E**piphyseal & ****E**ndosteal (nutrient supply to the medullary cavity)· ****A**pophyseal· ****C**anal of Volkmann (nutrient supply)· ****H**aversian Canals (central supply) --- ## Types of Bone Healing The type of bone healing is dependent on the removal of a fracture haematoma and the type of bone fixation performed. Absolute stability results in primary bone healing. ### Primary Bone Healing This occurs when **absolute stability** is provided to a fracture fixation resulting in **no callus formation**. Normal bone architecture is restored when osteoclasts provide a guide for blood vessels to cross the fracture site. A clinical example is a compression plate. Key aspects to this type of bone healing are: - No callus formation - No inflammatory or proliferative phases of healing - Haversian remodelling/osteonal bone remodelling ### Secondary Bone Healing This occurs when absolute stability is **not** provided to a fracture fixation resulting in **callus formation**. Clinical examples include K-wires, external fixators, and casting/splinting. Key aspects to this type of bone healing are: - Callus formation - Fracture haematoma occurs - Bone healing via endochondral ossification This is different to [bone graft incorporation ](https://www.theplasticsfella.com/bone-grafts/#bone-graft-healing-and-incorporation)seen in bone grafts. 🤓 ****Fun Fact:** a callus is soft, immature woven bone and hyaline cartilage created by osteoblasts and chondroblasts, respectively. It becomes a hard callus (mature woven bone) when the osteoid is mineralised with hydroxyapatite. --- ## Stages of Bone Healing There are 5 phases to bone healing: haematoma, inflammation, proliferation, callus formation, and remodelling. Bone healing is reliant upon osteoblasts and osteocytes. They help form new bone and maintain calcium homeostasis. The 5 phases of bone healing are as follows: 1. **Haematoma:** a "haematoma" is formed at the fracture site. 2. **Inflammation**: haematoma granulates & osteoclasts remove necrotic bone. 3. **Proliferation** of periosteal and endosteal cells at the cortex. 4. **Callus** formation & transformation from a soft callus (osteoid) to a hard callus. 5. **Remodelling** of woven bone to lamellar bone There are some similarities to bone and [wound healing](https://www.theplasticsfella.com/wound-healing/) \- but don't get confused! 🤓 ****Memory Hook for "Bone Cells":**· Osteo****B**lasts ****B**uild bone by producing osteoid.· Osteo****C**ytes maintain ****C**alcium hemostasis in the bone matrix.· Osteo****CL**asts ****CL**ean up the bone (bone resorption) --- ## Complications of Bone Healing Successful bone healing requires several factors to work together. Sometimes this doesn't occur for a variety of reasons. This can lead to some of the following complications 1. Malunion 2. Non-union 3. Delayed union These complications can be treated by [bone grafting](https://www.theplasticsfella.com/bone-grafts/#indications-for-bone-grafts). --- ## Flashcards ⚡ Evidence-based flashcards are designed for active recall and spaced repetition of the verified information you are currently studying.They are continually updated and are for thePlasticsPro users.