Flashcards in Bone Healing II Deck (96):
Two types of bone
Cortical and cancellous
Two words that describe cortical bone
Dense and compact
Cortical bone is most often found in bones that are ______ __________
4 words that describe cancellous bone
less dense, lattice-like bone
Cancellous bone is not as strong as cortical bone but it is more _________ and may contain _____ ______
Vascular, bone marrow
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?
What connect the haversian system together?
Channels that run perpendicular to the haversian canals allowing blood vessels to travel from the outside of the bone to the center
Cancellous bone consists of interconnected bands of tissue called ______
Thicker trabeculae may contain _______
Cancellous bone typically contains more irregularly arranged _________
Another term for cancellous bone
Bone building cells
Bone removing cells
Cells that reside in cavities within bone and reach through to network with other cells of the same type
These cells within the bone transfer nutrients and wastes and send signals based on stress and strain
Develop from osteoblasts that get trapped in mineralized bone
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
To create bone, osteoblasts create _______
Collagen is _____ but has little compressive strength
What mineral is deposited into collagen?
Hydroxyapatite is ______ but brittle
These two combine to make a material that is both strong and flexible
Thick fibrous membrane that covers the entire outside surface of the bone except at the joints
The periosteum contains blood vessles and nerves as well as _________ _________ which will become osteoblasts
A thin layer of tissues that lines the inside surface of bone as well as the hollow space inside the metaphysis of long bones
A soft tissue that contains stem cells
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?
Where is red bone marrow found?
Interior of flat bones, vertebrae, and in cancellous bone in metaphases of long bone
Where is yellow bone marrow found?
Inside the medullary canal of long bones
The process by which the body continually replaces areas of old necrotic bone with new bone tissue
Bone remodeling steps
1. Body identifies areas of bone that need replacement
2. Bone lining cells signal osteoclasts and recruit them
3. Osteoclasts arrive, attach to bone, create acid environment and create a void
4. Osteoblasts are recruited after sufficient bone removed
5. Osteoblasts fill void with osteoid
6. Osteoid mineralized to become new bone
7. 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
Time it takes to go from resting phase through modeling and back to resting phase
During the remodeling phase, the immediate bony area is initially _____________
Following the bone remodeling cycle, the mineral density of the region will continue to increase over the next ______ years
Bone remodeling and _____ _______ are the same
The term creeping substitution is most commonly used when referring to the incorporation of a ______ ______ into _____ _______
Bone graft into living bone
To remodel cancellous bone, osteoclasts make pits in the bone named ________ _______
After osteoclasts make pits in the bone named Howship's lacuna, what happens?
Osteoblasts then arrive at the site and fill the pit with osteoid which then mineralizes over a period of days to months
What do osteoclasts form to remodel cortical bone?
A cutting cone that tunnels through bone
After the osteoclasts form a cutting cone that tunnels bone, osteoblasts forming concentric rings of ______ to the close the tunnel
What forms in the center of the tunnel created by the cutting cone in cortical bone?
A blood vessel that forms in the center of the tunnel that then provides osteoblasts to the site (this result is a haversian system)
Define Wolff's Law
Bone is built where stresses require it and resorbed where stresses are absent
When does fracture repair happen?
When a bone is broken
When does spinal fusion occur?
When surgical intervention is needed to stabilize a region
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)
Blood fills the area around and between the fractured pieces, creating a hematoma. At the same time, immune cells, such as white blood cells, rush to the site leading to inflammation. Osteoclasts are also attracted and begin to remove dead bony tissue. Begins within hours of fracture and continues for 2-3 weeks.
Inflammation Phase of Fracture Repair
Cells invade the hematoma and begin to lay down fibrous tissue, cartilage and osteod to create a soft callus (3 weeks). The size of the callus is related to the stability of the fracture site. The more stable the fracture, the smaller the callus. The soft callus provides stability to the fracture and is gradually replaced with woven bone (hard callus) through endochondral ossification or intramembranous ossification (3-4 months)
Repair Phase of Bone Fracture
Once bone unites the fractured fragments, remodeling begins according to Wolff's law to return the bone to its original shape (up to 7 years)
Remodeling Phase of Bone Fracture
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
Three stages of bone graft incorporation
Describe the fusion process
Initially a hematoma
Soft then hard callus
Callus, along with bone graft, remodeled into living host bone
Other differences between fracture and bone healing
Bone healing needs large volume of graft
During repair phases, blood vessels must grow into graft to supply nutrients and stell cells to serve that region
Lifestyle factors that impact fusion
Bone relocated from elsewhere in the patient's body
Bone taken from another member of the same species
Bone taken from a member of a different species
Substitute for bone graft artificially created to mimic bone in body
Ability to provide framework (scaffold) for new bone growth
Ability to induce bone growth (satisfies chemical requirements for a fusion)
Ability to grow into bone (contains live bone cells) and satisfies the biologic requirements for a fusion
The gold standard in bone grafting
Bone marrow removed surgically from the inside of bones
Bone Marrow Aspirate
Non-specific grafts (i.e. strut grafts) available in the form of whole or part of bones
Grafts designed to be implanted without any modification by the surgeon
Who discovered demineralized bone matrix?
Dr. Marshall Urist
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
Osteoconductive, Osteoinductive, Osteogenic
Better known as Plaster of Paris, dissolves in a matter of weeks
The OG Synthetic Graft Material
A chemical compound consisting of calcium and phosphate
Mimics the mineral content of bone
A mineral compound consisting of calcium, phosphate, and hydroxyl ions
Commonly mixed with B-TCP to slow resorption rate of BTCP
Polymer used as bone cement
Family of proteins found in bone
Has the ability to provide the framework (scaffold) for new bone growth (satisfies structural requirements for a fusion)
Has the ability to induce bone growth (satisfies the chemical requirements for a fusion)