Exam 2 - MSK 1B bone fx and healing Flashcards
Define fracture
Any defect in the continuity of a bone
What are the three etiology classes of fractures?
- Sudden traumatic fx
- Stress or fatigue fx
- Pathological fx
Describe Sudden Traumatic Fx, Stress/Fatigue Fx, and Pathological Fx
Sudden Traumatic=sudden episode of excessive force
Stress/Fatigue=Repetitive normal force. Doesn’t appear on xray until healing
Pathological Fx=Normal force on abnormal bone d/t bone failure
Definite Comminuted Fx, Pathological Fx, and Incomplete Fx
Communited=fx of 3+ fragments
Pathological=fx in area of preexisting bone disease
Incomplete=fx does not span across entire cross-section, no separate segments
Define Semental Fx and Butterfly Segment Fx
Segmental=middle fragment separated by proximal and distal segments
Butterfly Segment=Like Segmental but not through cross-section
Define Stress Fx and Avulsion Fx
Stress=fx caused by repeated loading of bone
Avulsion=tendon or ligament pulls off bone from insertion site
Define Displacement fx
Proximal and Distal segments not lining up
Define Angulation fx
Direction where the distal fracture “points”
What are the differences between Primary and Secondary Bone Healing
Primary=rigid bone stabilization takes longer, no calus formed
Secondary=less rigid bone stabilzation, early calus forms to provide stabilization
What are the three phases and time ranges of Secondary Bone Healing?
- Inflammatory Phase (1-2 weeks) “acute”
- Reparative Phase (Several months)
- Remodeling Phase (months to years)
What happens during the Inflammatory Phase of Secondary Bone Healing?
Increased blood flow forming hematoma. Osteoclasts remove damaged bone. Growth factors stimulate fibrobasts, osteoblasts, etc. Fx line on xray.
What happens during the Reparative Phase of Secondary Bone Healing?
Soft Callus forms and turns into Hard Callus by Osteoblasts mineralizing. Considered immature bone. Fx line starts to disappear.
What happens during the Remodeling Phase of Secondary Bone Healing?
Immature bone replaced by mature bone. Fx line disappears.
What are the two types of Primary Bone Healing? Describe.
- Gap Healing-Rigid fixation with small gaps and no movement at fx site
- Contact Healing-Rigid fixation with no gaps and no movement
Kid, Adolescent, and Adult fx healing times
Kids=4-6 weeks
Adolescents=4-8 weeks
Adults=10-18 weeks
Casts, Intramedullary rods/nails, Pins, wires, and screws are what kind of bone healing?
Secondary
Compression plate is what sort of bone healing? How does it differ from the other?
Primary. No weight bearing which takes longer. No periosteal callus formation.
What is different in External Fixation with “less rigid fixation” and “very rigid”?
Less rigid=Secondary healing. Callus forms.
Very rigid=Primary healing. No callus forms.
What is Wolff’s Law?
Mechanical stress leads to more bone density. Removal of mechanical stress decreased bone density.
Describe “delayed” or “non-union” healing complication
Segments don’t join back together. Might have a little bump.
Describe Avascular Necrosis and two most common sites
Cell death at site of fx. Scaphoid and Femoral Head.
Which part of the bone is called the “growth plate”?
Epiphyseal Plate
Define Type 1 Salter Harris
Disruption of the growth plate. Distraction or slip injury.
Define Type 2 and Type 3 Salter Harris
Type 2=Fx line through growth plate and metaphysis
Type 3= Fx line through growth plate, metaphysis, epiphysis
Define Type 4 and Type 5 Salter Harris
Type 4=Fx through metaphysis, growth plate, and epiphysis
Type 5=compression injury of growth plate
Osteoperosis, Osteomalacia, and Paget’s Disease represent what type of disease of the bone?
Metabolic disease. Increased or decreased bone density.
Apophysitis (epiphysitis) and Osteonecrosis (avascular necrosis) are what types of bone disorders? Related to where?
Osteochondroses. Related to secondary ossification center.
What is Osteopenia?
Low Bone Mineral Density. SD 1-2.5. Not severe enough to be osteoperosis.
What is Osteoperosis (in general)? What SD and cell activity?
Severe decrease of BMD, SD 2.5+. Osteoclastic activity more than Osteoblastic activity.
Define Primary Osteoperosis vs Secondary Osteoperosis
Primary=General decrease in bone density unrelated to underlying disease, condition, or medication
Secondary=Bone density loss due to disease or medication
Describe Type 1 and Type 2 of Primary Osteoperosis
Type 1=Post-menopausal women. Primarily in cancellous bone.
Type 2=Age related (over 75). In both cancellous and cortical bone.
What are the describe the three phases of bone mass growth and loss
- Growth Phase=90% of bone density formed. Until growth plates close.
- Consolidation Phase=10% formed until Peak Bone Mass reached
- Involution Phase=Gradual loss of bone density from normal and pathological factors
Describe Peak Bone Mass and age when it happens
Bone forming faster then resorption. Around 30 y/o.
Define and describe the Involution Phase
Normal age-related bone loss. 0.5-1% per year.
Define and describe Post-Menopausal Bone Loss
Estrogen protects women from bone loss which accelerates to 3-5% for first ten years after menopause then slows down.
Estrogen loss in menopause leads to higher levels of ______ and reduced levels of _____
Higher levels of RANKL, reduced levels of OPG
RANKL=promotes osteoclast maturation
OPG=inhibits osteoclast maturation
What does Raloxifine do to OPG levels?
Stimulates more OPG production, which inhibits osteoclast maturation
What type of bone is most effected by post-menopausal osteoperosis? Two bones in particular?
Cancellous (trabecular) bone
Metaphysic of long bone-wrist and femur
Which bone type is most sensitive to conditions that alter osteoblast and osteoclast activity? Why?
Cancellous (aka Trabecular) bone. Large surface area and not a “large bone mass” to begin with compared to cortical bone
Which bone type loses more mass and more sensitive to loss in post-menopausal women?
Trabecular (aka Cancellous) bone.
What are some risk factors of osteoperosis?
Hormonal status (low estrogen), physical inactivity, genetics, medications, tobacco, alcohol, diet
What is the “Female Triad”?
Eating disorder, amenorrhea, osteoperosis
What is a BMD test? What is the “gold standard” and scores?
Bone Mineral Density test. DEXA is gold standard.
Normal=BMD less than 1
Osteopenia=BMD between 1 and 2.5
Osteoperosis=BMD above 2.5
Define Osteomalacia and etiology
Insufficient mineralization of bone but no actual bone loss. “Soft bones.” Poor nutrition (such as VitD) or diseases/meds.
What are “Loozer Zones” and “Milkman Fractures”?
Pseodofractures perpendicular to bone from poorly mineralized osteoid matrix. Osteomalacia.
What is Ricket’s
Childhood osteomalacia. Bowing of legs with gravity. Type of Osteomalacia.
What is Paget’s Disease? Who get it and what bone does it effect?
Enlarged, deformed bone of poor quality. Distortion of bone formation for resorption in trabecular (cancellous) bone. Men over 50 more than women.
What is Osteochondroses? Age group? Two examples?
Self-limiting disorder of bone growth involving ossification centers. In kids.
1. Osteonectrosis (avascular necrosis)-death of bone d/t loss of blood supply from fx or other pathology
- Apophysitis (epiphysitis)-traction (too much torque) of secondary ossification centers
What is Osgood-Schlatter Disease?
Type of apophysitis. Patella ligament pulling/traction on tibial tuberosity. Type of Osteochondrosis.
What is Olecranon Apophysitis?
Type of Osteochondrosis. In young throwing athelets. Triceps tendon pulling on secondary ossification center of Olecranon.
What is Sever’s Disease?
Type of Osteochondrosis. Achilles tendon traction (“pulling”) on secondary ossification center of calcenous.
Define Osteomyelitis
Inflammation of bone cause by bacteria or other infectious agent
What is “lift-off” in Osteomyelitis? Who gets it?
Kids. Inflammation which “lift offs” periosteum from sub-periosteal abscess and disrupts blood supply.
What is a Squestrum?
Necrosis of bone from osteomyelitis in kids.
Where do adults and kids get osteomyelitis? How does it present in each?
Adults=lumbar spin. Low fever with back pain.
Kids=metaphysis near growth plate in long bone. High fever with local pain, redness, and swelling.
Describe Primary Benign Bone Tumor vs Primary Malignant Bone Tumor
Benign=slow growing, well-differentiated, bone contains tumor in sclerotic rim
Malignant=Aggressive, fast growing, spread beyond cortical bone
Moth Eaten bone consistent with which cancer? Describe.
Myeloma. Less defined margins, surrounding lytic or partially lytic area.
Permeative bone consistent with which cancer? Describe.
Ewing Sarcoma. Poorly defined margins. Abnormal lytic bone merged throughout bone.