Bone Healing Updated Flashcards
Two types of bone
Cortical and cancellous
Describe cortical bone
Dense and compact
Describe cancellous bone
less dense, lattice-like bone
What is cortical bone arranged in units of?
Osteons aka haversian systems
Osteonic consist of ______ layers of bone arranged around a central ___________ ___________
concentric, haversian canal
What does the haversian canal contain?
Blood vessels and nerves
What are interspersed between the concentric layers of bone in the osteons?
Osteocytes
What connect the haversian system together?
Volkmann’s Canals
Channels that run perpendicular to the haversian canals allowing blood vessels to travel from the outside of the bone to the center
Volkmann’s Canals
Cancellous bone consists of interconnected bands of tissue called ______
Trabeculae
Thicker trabeculae may contain _______
Osteons
Cancellous bone typically contains more irregularly arranged _________
Lamellae
Another term for cancellous bone
Trabecular bone
Bone building cells
Osteoblasts
Bone removing cells
Osteoclasts
Cells that reside in cavities within bone and reach through to network with other cells of the same type
Osteocytes
These cells within the bone transfer nutrients and wastes and send signals based on stress and strain
Osteocytes
Develop from osteoblasts that get trapped in mineralized bone
Osteocytes
Line the outer surface of bone
Bone lining cells
These cells direct mineral update and release in bone
Bone lining cells
Send signals to initiate bone removal and formation
Bone lining cells
What mineral is deposited into collagen during bone growth?
Hydroxyapatite
A soft tissue that contains stem cells
Bone marrow
The two types of stem cells in bone marrow
Mysenchymal and hematopoietic
What 5 things do mysenchymal stem cells create?
Cartilage, bone, blood vessel, nerve, and fat cells
What do hemapoietic stem cells create?
Blood cells
Define remodeling
The process by which the body continually replaces areas of old necrotic bone with new bone tissue
Bone remodeling steps
- Body identifies areas of bone that need replacement
- Bone lining cells signal osteoclasts and recruit them
- Osteoclasts arrive, attach to bone, create acid environment and create a void
- Osteoblasts are recruited after sufficient bone removed
- Osteoblasts fill void with osteoid
- Osteoid mineralized to become new bone
- Some osteoblasts encased in mineralized bone and become osteocytes, others finish filling void and remain outside of the new bone as bone lining cells
The remodeling of old necrotic bone or bone grafts
Creeping substitution
Following the bone remodeling cycle, the mineral density of the region will continue to increase over the next ______ years
2-3
The term creeping substitution is most commonly used when referring to the incorporation of a ______ ______ into _____ _______
Bone graft into living bone
Define Wolff’s Law
Bone is built where stresses require it and resorbed where stresses are absent
What are the three stages of bone repair?
Inflammation Phase (0-3 weeks) Repair Phase (3 weeks to 4 months) Remodeling Phase (4 months to 7 years)
Difference between fracture healing and fusion
In fracture healing, you are taking two bone fragments that were once united and putting them back together
In a fusion, two or more separate individual bones are induced to grow together
Bone that is removed from one place and transferred to another
Bone graft
Three stages of bone graft incorporation
Inflammation
Repair
Remodeling
Lifestyle factors that impact fusion
Poor nutrition Tobacco Diabetes Rheumatoid Arthritis Steroids Cytotoxic Drugs Radiation
Bone relocated from elsewhere in the patient’s body
Autograft
Bone taken from another member of the same species
Allograft
Bone taken from a member of a different species
Xenograft
Substitute for bone graft artificially created to mimic bone in body
Synthetic
Ability to provide framework (scaffold) for new bone growth
Osteoconductive
Ability to induce bone growth (satisfies chemical requirements for a fusion)
Osteinductive
Ability to grow into bone (contains live bone cells) and satisfies the biologic requirements for a fusion
Osteogenic
The gold standard in bone grafting
Autograft
Bone marrow removed surgically from the inside of bones
Bone Marrow Aspirate
Grafts designed to be implanted without any modification by the surgeon
Machined Grafts
When the mineral content is removed from allograft, this material remains osteoinductive
Demineralized Bone Matrix
Usually consists of a power mixed with a carrier that facilitates deliver of the demineralized bone into the surgical site
Demineralized Bone Matrix
Demineralized Allograft
Osteoconductive, Osteoinductive
B-TCP
Osteoconductive
Hydroxyapatite
Osteoconductive
BMP
Osteoinductive
Has the ability to provide the framework (scaffold) for new bone growth (satisfies structural requirements for a fusion)
Osteoconductive
Has the ability to induce bone growth (satisfies the chemical requirements for a fusion)
Osteoinductive
Has the ability to grow into bone (satisfies the biologic requirements for a fusion)
Osteogenic
Bone is ___% organic
30%
Bone is ___% inorganic
70%
Autograft
Osteoconductive, osteoinductive, osteogenic`
What are four things a surgeon can do to create a good environment for fusion?
Bony apposition (tight fit on bone graft)
Maximize surface area
Bloody pathway
Stable fixation
