ANATOMY, BASIC
Dr. Murat Çalışkan
Bone: The basic substance of bone, collagen fibers and organic consists of salts stored in the matrix
– Compact (cortical) bone;
• Cylindrical structures consists of concentric rings that are settled in the form of slats or plates
• Blood vessels are located in the center of each Haversian system and nutrition is through them.
– Cancellous bone;
• The bone matrix consists of closed spaces by
needle or trabeculular shaped. Bone marrow fills
the gaps between this.
Epiphysis .
• Epiphysis line is the area of longitudinal growth in the bone.
• It is the end of the cartilage of the growing long bone.
• A cartilaginous disc is located
around the fibrous tissue.
Periosteum
Completely surrounds the bone except the joint face.
• When the elastic limit of bone is forced or broken, it contributes to the formation of new bone.
•Healing and growth is an integral part of the remodeling of the bone.
• At the level of epiphyseal growth plate, it
takes the name of the pericondral ring.
https://stefaanverbruggen.com/publications/are-all-osteocytes-equal-multiscale-modelling-of-cortical-bone-to-characterise-the- mechanical-stimulation-of-osteocytes/
Bone Cells
• Osteoblast:
– The extracellular matrix in which collagen lies and play a role in mineralization.
- Collagen and basic substance synthesis form the formation of bone.
• Osteocyte
• Osteoclast:
- They are multi-core large cells responsible for the resorption of bone.
- - Often on the surface of the bone, known as howship is located in shallow sediments.
- – It develops from the hematopoietic system.
Three basic physiological functions of bone cells:
- Calcium transport.
- Protection of biophysical and bioelectrical properties.
- Hormonal response.
Bone Formation
in two ways:
1. Intramembranous ossification:
- Cartilage formation is not visible.
- Vascularization and osteoblastogenesis are observed in connective tissue
- The first bone formation occurs as a guide to the primary spongiosus bone, and is from the collagen fibers that show random arrhythmias it is established.
–Lamellar bone is formed after primary
spongiosus bone, has been organized with
havers systems and responds to mechanical
stimuli from the environment
Endochondral ossification:
• In this formation, firstly, cartilage is observed as in embryonik period.
• After vascular invasion, cartilage tissue is
replaced by bone tissue.
BASIC FRACTURE HEALING
Fracture healing begins from the moment it is broken and consists of three stages:
Inflammatory Phase Reparative Phase Remodeling Phase
These three periods start before the end of one
of the other continues and the longest period is
the period of remodelization
.1- Inflammatory Period:
- Hematoma is formed between the broken ends.
- This period covers the first 3-4 days.
- hematoma is extremely important in terms of fracture healing and emptying of the broken hematoma can cause some problems.
The broken hematoma is partly responsible for keeping the broken ends together with the
tension it provides to the intramembranous.
Necrosis develops between 1-5 mm at
broken ends.– Inflammatory mediators
released from dead cells in necrotic bone
ends and broken haematomas increase
capillary membrane permeability leading
to inflammatory cells in the region of red
blood cells (polymorphous leukocytes ,
macrophage and lymphocytes).
2- Repair Period:
In the first 48 hours of this period, cell proliferation starts from the layers of periost, endost and Havers channels near the fracture ; resorption continues along the broken line.
- Cells fill gaps in broken ends as a result of cell proliferation.
– Cells filled with broken lines help repair the
cellular continuity of the bone.
- With proliferation, chondroblasts and osteoblasts develop, resulting in cartilage and bone tissue.
- Osteoblasts are transformed into osteocytes (intramembranous) or enchondral ossification provides bone continuity.
- Necrotic bone resorbed and replaced with new bone tissue.
- In summary, macrophages and osteoclasts
spreading into the hematoma at the time of repair
provide the elimination of dead bone and osteoblasts
provide bone formation.
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Fibrous callus:
• Fibrous callus is formed by the arrival of osteoblasts and chondroblasts one week later and fibrin nets formed by clots in the fracture area and the young collagen produced by fibroblasts
• This callus initially formed is soft (not
radiologically).
Fibrocartilagenous callus
• osteoid is produced from osteoblasts and chondroblasts are converted to osteoblasts.
• As a result of the collapse of calcium salts (hydroxyapatite) slowly, the front callus is formed.
This process takes 2-3 weeks.
• The resulting callus is hard but still unstable.
• Thus, the stability between the ends of the fracture increases.
• With increasing stability, blood vessels that play
a primary role in the formation of
fibrocartilagenous callus begin to reshape in the
medulla.
Ossous callus
- periosteum and endosteous osteoblasts begin to produce osteoid which is the bone matrix.
- The front callus is replaced by a bony callus.
- This step is reached in 4-6 weeks. Bone healing
completed.
3- Remodelling
- Then it becomes remodeling (6. after the month).
- - The bone around the fractured area is resorbed, the medullary channels are
opened and the normal bone structure is acquired.
- Remodelization occurs according to the laws of Wolff.
- Remodeling may start towards the end of
the repair period and continue for many
years after the fracture has healed
Factors Affecting Fracture Healing unfavorable:
-
High-energy traumas and extensive soft tissue damage.
- Separation of broken ends.
- Interposition of soft tissues.
- Damage to the vessels.
- Excessive dissection and soft tissue damage
during surgical reduction.
- The fracture is transverse, segmental or segmental (spiral and oblique fractures healed more quickly), open fracture (hematoma discharge, contamination and infection due to the possibility of and excessive soft tissue damage).
- The failure of reduction.
− No good stabilization.
− Insufficient immobilization.
− broken-site infection.
−
older age
−Fracture of the joint (synovial fluid due to the disruptive effect of fracture healing).
- A pathological condition that existed in the bone.
- does not contain spongiosa or have high fracture of cortical bone content.
- - All kinds of systemic diseases affecting
nutrition and healthy metabolism (diabetes,
malignancies, systemic infections, anemia,
etc.), chemotherapy, radiotherapy and
corticosteroids.
In addition to the positive effects of negative factors on the opposite situation,
– Electrical currents.
– Magnetic field.
– Ultrasound.
- Hyperbaric oxygen applications.
Low power laser application.
- Anabolic steroids.
- Vitamin D.
-Calcitonin,parathormone, prostaglandins, BMP (Bone Morphogenetic protein), growth hormone, growth factors.
- Surgical bone grafting and demineralization bone matrix.
- Gene therapy.
Factors Affecting Fracture Healing Favorable:
Complications in Fracture Healing
1- De-layed union:
Fractures that heal more slowly than anticipated.
Most long bone frsctures have ragiographic evidence of bone bridging the fracture lines by 12 weeks
- This bone healing anomaly is observed more frequently in
high-energy traumas and in blood-limited limited bones.
Fracture nonunion is defined as an arrested fracture repair process,
which requires surgical intervention to create an enviroment conductive to bone healing
3-Mal-union:
Malunions are healed fractures in which anatomic bone alignment was not achived or maintained during healing.
• Mal-union; can be in the form of angulation, shortening, rotation or combinations.
The most important mal-union is the mal-union of joint fractures.
Deformities may be classied as valgus, varus,
antecurvatum or recurvatum
4- Osteomyelitis
İnflammation of bone and bone marrow due to bacteria (staphylococcus, salmonella, brucella etc.)
-osteomyelitis occurs when bacteria reach the bone directly or through blood circulation from the skin wound associated with the bone.
-may be acute or chronic.
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REFERENCES
Ankara Üniversitesi Açık Ders Malzemeleri Ortopedi ve Travmatoloji Prof. Dr. Hasan Bilgili Ders notu.
