Flashcards in Fractures/ Fracture Healing Deck (123):
What are 2 types of excessive loading that cause fractures?
- One time events
- Repetitive loading cycles
What are 8 sets of descriptive terms for fractures?
- If skin is broken
- Anatomic site/ extent of fracture
- Complete/ Incomplete
- Fracture segment alignment
- Direction of the fracture line
- Special features
- Associated abnormalities
- Special types of fractures
What are the terms for skin broken or not broken fractures?
Open vs Closed.
What are risks of open fractures?
What are 2 examples of fracture sites with specific names?
How are shafts of long bones divided in terms of naming the fracture?
- Proximal/ middle/ distal thirds
What are the descriptions of fractures near joints?
- Intra-articular (inside joint)
- Extra-articular (Near joint on proximal or distal bone)
What type of fracture can be splinted or casted?
An incomplete fracture in which the cortex is partiall intact.
What is a complete fracture?
All cortices are disrupted around the circumference of the bone.
How are complete fractures stabilized?
If there are more than 2 complete fractures, how is it described?
How are fracture segment alignments described?
- Distal relative to proximal
What are 5 types of displacement?
- Medial/ lateral
- Anterior/ posterior
- Superior/ inferior
- Overriding/ distracted
What are terms used to describe the amount of displacement?
- % of shaft, cortex
How is angulation described?
- Direction of distal segment.
How is an apex described?
- The point of the two segments of the fracture.
How is the direction of the fracture line described?
- In reference to the long axis of the bone.
Ex) transverse, oblique, longitudinal, spiral
What type of force may cause a transverse fracture?
How are transverse and longitudinal fractures aligned to the long axis of the bone?
- Parallel (longitudinal)
- Perpendicular (transverse)
What type of force can cause an oblique fracture?
- Compression on bending and torsion.
What type of force causes a spiral fracture?
What differentiates a spiral fracture from an oblique fracture?
- Sharp edges around vertical segment
What type of force causes an impaction fracture?
What type of bone tends to heal quickly from impaction fractures?
- Cancellous bone
ex) vertebral body, metaphysis
How well do impaction fractures tend to heal generally?
(relatively stable fractures)
What is a Hill-sachs lesion?
Humerus dislocated and impacted on glenoid causing deformation in the humeral head.
What causes an avulsion fracture?
- Tensile loads from ligaments and tendons fracture bone at the site of the attachment.
How are avulsion fractures described?
- Location, and fracture line.
What are 3 common sites of avulsion fractures?
- Deltoid ligament/ malleolus
- Rectus femoris/ AIIS
- Achilles/ Calcaneus
What are associated abnormalities with fractures?
How longs does it take for a stress fracture to become visible on plain film, and what is visible?
- 2 weeks for bony callus to become visible./
What is a pathologic fracture?
- Fracture due to weakened bony architecture.
What cause periprosthetic fractures?
- Bony adaptations around joint replacements
What can cause a bone graft fracture?
Why are fractures different in children?
- Bones are more pliable,and structures are incomplete
- Growth plates
What is an incomplete fracture extremely common in children?
What is a torus fracture?
A common incomplete fracture in children, where one side of a bone buckles in on itself.
What is a plastic bowing fracture?
- Common incomplete fracture in children with a failure at the microscopic level leading to plastic deformation.
- No distinct fracture line
What type of fracturesare plastic bowing fractures often coupled with?
What is a type I Salter-Harris (SH) fracture?
Fracture transversely through cartilage.
What is a type II SH fracture?
Fracture through cartilage and towards into metaphysis.
What is a type III SH fracture?
Fracture through cartilage and into epiphysis.
What is another name for a type III SH fracture?
Secondary Ossification Fracture.
What is a type IV SH fracture?
Through cartilage, and into the metaphysis and epiphysis.
What is a type V SH fracture?
- Compression/ Crush fracture.
What is a type VI SH fracture?
Crush on one side of bone/ cartilage.
What is a type VII SH fracture?
- Epiphyseal fracture only.
- Secondary ossification center
What is another name for a type VII SH fracture?
What is a type VIII SH fracture?
Through metaphysis only.
What is a type IX SH fracture?
Periosteum tears/ rips.
No other fractures/ crush.
How do SH fractures affect angulation deformities in different age groups?
According to skeletal maturity/ activity of growth plates.
Very young: High potential
Children: Moderate potential
Adolescence: Lower potential
Adult: No chance.
Where do growth deformities due SH fractures usually occur?
In under-developed countries.
What does the amount of reduction of a fracture depend upon?
- Skeletal age.
What type of fractures result in relatively risk free reduction?
What are 4 indications for reduction of an open fracture?
- Closed won't work
- Intra-articular fracture
- Blood or nerve compromise
- Desire early mobility (other joints)
What are 4 indications for the use of fixation?
- Avoidance of further injury
- Maintenance of bone length
- Maintenance of alignment
- Allows for calcification of callus
What are 3 types of external fixation?
What are 3 types of internal fixation?
- Plate nails
What is a non-union?
When a fracture fails to heal.
How is fixation related to nonunion?
- If the fixator bears too much force, then the bone is not sufficiently stimulated to grow/ increase density.
- Sometimes the bone may undergo significant degradation.
What is a malunion?
- Fracture fails to heal properly.
What is the treatment for a malunion?
Rebreak the bone, and hope it heals correctly.
What is a pseudoarthrosis?
- Joint formed at fracture site due to motion./
When can it be determined that a pseudoarthrosis has in fact been formed?
8 - 12 weeks with no healing.
What type of motion is especially detrimental to the healing process?
How does the periosteum differ throughout aging?
- Thicker in children
- Thinner and more firmly attached in older persons
What are the 3 key roles of the periosteum in fracture healing?
- Reducing and aligning the fracture
- Maintaining (stabilizing) the fracture
- Serving as an osteogenic sleeve. (chondroblast and osteocyte supplier)
What tissue plays a large role in the rate and success of healing of fractures?
If a fracture is suspected during a clinical exam, what are the next steps?
- Take thorough history to determine if there
- Splint/ cast fracture
- Send to orthopod
- Confirm with radiograph
In whom are fractures always noticed? Who may miss them?
- The patients without sensory deficits always know
- Radiographs may deliver a false negative
In acute trauma situations, what is the fracture of secondary importance to?
- Circulatory concerns
- Neural concerns
What is unique about bone healing?
It heals with bone instead of scar tissue.
When does primary bone healing occur?
- When both ends of the fracture are compressed together and held rigidly by an internal or external fixation.
What is the mechanism of primary bony healing?
No callus is formed. Cortices heal directly into one another.
Is secondary or primary bone healing a faster process?
What is the 7 step process of secondary bony healing?
- Hemmorage of ruptured blood vessels in haversian system, periosteum, and endosteum
- Clot formation
- Proliferation of osteogenic cells from periosteum and endosteum (lining haversian canals) near and distant from the fracture site
- Pro-callus/ fibrous union formed by the entrance of dense fibrous tissue into the clot
- External callus formed from osteogenic cells in periosteum, and internal callus formed from cells in endosteum
- Cartilagenous callus gradually replaced by woven bone (high O2 tension), or by endochondral ossification (low O2 tension); both can happen in same fracture
- Lamellar bone forms over woven bone, and excess bone is resorbed
In an external callus, which portion has woven bone, and which portion is cartilaginous; why?
Edges: Woven due to high O2 tension (periosteum)
Center: Cartilaginous due to low O2 tension
Why is the internal callus created directly from woven bone?
Many blood vessels in haversian canal lead to high O2 tension.
How are the internal and external callus united?
By woven bone bridges, and endochondral replacement within cartilaginous callus.
How long does it take for excess bone in callus to be partially or completely resorbed?
1 - 5 years.
In what types of bones does spongy bone healing occur?
- Metaphyses or cuboidal bones
What is the 4 step process of spongy bone healing?
- Osteogenic cells from endosteum of trabeculae invade hematoma and laydown woven bone
- Healing begins at points of direct contact, and then spreads to bridge gaps
- Woven bone is replaced by lamellar bone
- Trabecular patterns according to the time average force patterns of Wolf's law.
How much distraction leads to a probability of 50 % fracture healing?
Gap of 1/2 bone diameter.
What amount of distraction has a less than 5% probability of healing?
Exceeds bone diameter.
How much distraction leads to a greater than 98 % change of fracture healing?
What healing processes are interrupted by distraction?
Osteogenic cells from periosetum and endoosteum do not invade the clot causing a procallus.
What amount of linear displacement leads to a >98 % chance of fracture healing?
Any amount of lateral displacement up to only 20% overlap.
How much does the fracture healing probability drop by when 20 % contact is lost due to linear displacement?
50 % chance of healing (48 % drop)
What is the probabilty of fracture healing when the total displacement has exceeded the total linear displacement by 20%?
What degree of angular displacement leads to a delay in the union of bone?
What is the delay in healing at 45 degrees of angular displacement due to?
Motion between the fragments.
What is the most common factor that prevents healing?
What factor determines the amount of shear required to disrupt healing?
The closer the fracture edges are approximated, the less amount of shear is required to damage healing.
Does shear refer only to side-to-side shear?
No; it also refers to torsional shear.
What amount of flexion must occur to slow healing?
Over around 20-30 degrees of flexion.
Flexure is not a huge factor on healing; what surprising effect does it have on some patients? Why does this occur?
Flexure strains can actually help to build a strong callus due to bioelectrical input/ Wolf's law.
What steps of healing can flexure interrupt?
The replacement of calluses with woven bone.
What steps of the healing process does pistoning interrupt?
- Clot formation
- Osteogenic cell infiltration
- Forming a fibrous callus
What 4 factors affect the duration of fracture healing?
- Age of the patient
- Site and configuration of the fracture
- Initial displacement of the fracture
- Blood supply to fracture fragments
What heals faster: bones surrounded by muscle, or subcutaneous bone?
Bone surrounded by muscle.
At what site does bone heal very slowly?
Does cancellous or cortical bone heal faster?
Do metaphyseal or epiphyseal fractures heal faster?
Do long oblique/spiral or transverse fractures heal faster?
Long oblique/ spiral.
Why does initial displacement of a fracture affect healing?
There is a greater tear of the periosteal tissues.
What occurs if one of two or more fractures lose its blood supply during healing?
The dead bone acts as a framework for new bone due to osteogenic cells from the vascularized segment.
What is required to assist in the healing process if one of the bones is devascularized?
- Rigid immobilization
- Prolonged period of time
What may occur if both fragments lose their blood supply? How is this treated?
- Bone may die and become resorbed into the body before it can heal.
- Prosthetic bone required.
When is a bony callus visible on x-ray generally?
2 - 3 weeks.
When do unions form in the UE, and LE? What activity is indicated?
UE: 4 - 6 weeks
LE: 8 - 12 weeks
Functional/ non-sport use
When does consolidation occur in the UE and LE? What does this indicate?
UE: 6 - 8 weeks
LE: 12 - 16 weeks
Bone is secure.
If there are symptoms of a fracture, but they do not appear on radiographs, how do you treat the patient?
As though they have a fracture.
Re-eval with radiographs in 1 - 2 weeks.
What are the PT's responsibilities immediately post-fracture?
- Provide first aid, ICB, splinting
- Get to ER, or orthopod depending on severity
What is not the PT's responsibility in an acute fracture?
DO NOT REDUCE THE FRACTURE.
What should a patient bring to the PT post acute care?
- Letters from MD
- Radiographs and radiologist's reports
- Exercise/ instructions of MD
What 4 factors should be considered by a PT in post-acute care of fractures?
- Present activity allowed
- Physical exam
What should be included in the history related to the fracture?
- Immediate treatment taken for fracture
If present activity allowed is not consistent with normal time frames for fractures, what should be done?
What other situations would lead to contact of the MD related to present activities allowed?
WB, motion not included on referral.
What should a physical exam of a fracture include?
- Active, passive, resistive and neurological tests above and below fracture site
- Posture/ gait screening
- Adaptive equipment considerations
- May test for union, but very carefully
What does treatment of a fracture consist of?
- Findings of physical exam
- Cause of joint ROM restriction
- Muscle shortening
- Problems with joint itself
- CV training
What should be considered when evaluating an ROM limitation?
- Muscle shortening?
- Joint problem?