Exam 1: Lecture 2 - Principles of Orthopedic Surgery I Flashcards
what are the 7 reasons for orthopedic sx
- stabilize fractured bones
- explore, debride, and stabilize injured joints
- replace damaged joints
- stabilize spinal column injuries
- decompress the spinal cord (IVDD)
- resect musculoskeletal tumors
- repair tendon and ligament injuries
what are the 2 goals of treat fractures, nonunions, or bone deformities
- bone union
- return to normal function
what are the 2 things we should do for surgical planning
choose implants and plan procedure and evaluate fracture, patient, and client
what are the specifics to evaluate fractures
identify which implants will achieve stability for the appropriate healing time and ensure selected fixation counteracts forces to bone
what is FAS in orthopedics
fracture assessment score
what are the things we should think about when we make a detailed plan for entire surgical procedure
- method of fracture reduction
- sequence of implant application
- possibilities for bone grafting
what can happen if we dont make a surgical plan
- prolonged operating times
- excessive soft tissue trauma
- technical errors
What are the 2 goals of fracture reduction
- reconstructing fractured bone fragments to normal anatomic configuration
OR - restoring normal limb function
what is the technique of fracture reduction
must overcome physiological processes like muscle contraction and fracture fragment overriding
what type of fracture reduction is this
anatomic reconstruction
what type of fracture reduction is this
normal alignment
what is closed reduction of a fracture
reducing fractures or aligning limbs without surgically exposing fractures bones
what is open reduction of a fracture
surgical approach to expose fractured bone segments and fragments (anatomically reconstructed and held in position with implants)
what are the advantages of closed reduction
enhances biological environment by preserving soft tissue & blood supply, decreases risk of infection (bc stays closed), and reducing operating time
what are the disadvantages of closed reduction
difficulty of accurate reconstruction of reducible fractures
what are the 2 ways open fracture reductions can be further classified as
- limited open reduction
- open but dont touch reduction
what is limited open reduction
lever transverse fracture into position or securing oblique fracture with lag screws or cerclage wire
what is an “open but dont touch” reduction
realigning bone and placing a plate but fracture fragments and hematoma are NOT manipulated
what are the 4 advantages of open reduction
- visualization and direct contact with bone fragments
- direct placement of implants possible
- bone reconstruction
- cancellous bone grafts can be used
why is visualization and direct contact with bone fragments an advantage of open reduction
facilitates anatomic fracture reconstruction
why is bone reconstruction an advantage of open reduction
allows bone and implant to share loads and results in stronger fracture fixation
why are cancellous bone grafts a good thing for open reduction of fractures
enhances bone healing
what are the 3 disadvantages of open reduction
- increased surgical trauma to soft tissue and blood supply
- diminished biologic environment
- greater opportunity for bacterial contamination
what are the indications for an open fracture reduction
- articular fractures
- simple fractures allowing anatomic reconstruction
- comminuted non-reducible diaphyseal fractures of long bones
when is a closed reduction indiciated
- greenstick and/or non-displaced fractures of long bones below elbow and stifle
- comminuted non-reducible diaphyseal fractures of long bones treated with external fixations
what are the 2 ways of doing a direct reduction
- counteracting muscle contraction
- manual distraction of segments
what happens with counteracting muscle contraction
causes bone segments to override and major difficulty in anatomic reduction
what happens with manual distraction of segments
using bone-holding forceps to eventually fatigue muscles to allow reduction
explain when/how you do a direct reduction
for transverse fractures
bone ends lifted and brought into contact, force slowly applied to reduce bones in normal position
how do you do direct reduction using a lever
reduce overriding bone segments of transverse fractures by placing a level between overriding bone segments and apply pressure gently
what type of reduction is this
direct reduction
what type of direct reduction is this
direct reduction using a lever
what type of direct reduction is this
direct reduction using bone holding forceps
how do we do a direct reduction with bone holding forceps
- return bone segments of long oblique fracture into reduction with bone-holding forceps
- place pointed reduction forceps at angle to fracture line
- pointed reduction forceps gently closed
what is IMPORTANT to remember about direct reduction
- rough bone handling of bone cause more fragmentation
- bone must be inspected for fissure fracture lines
what is a direct reduction with butterfly fragment
anatomic reconstruction of fracture with a large butterfly fragment
what kind of direct reduction is this
direct reduction with butterfly fragment
when do we use indirect reduction
for non-reducible fractures
explain why non-reducible fractures are managed with indirect reductino
it preserves biology and bridging fixation provides mechanical support
what is indirect reduction
process of restoring fragment and limb alignment
explain how an indirect reduction using an IM pin
a pin is driven normograde thru proximal bone segment to fracture site
what type of indirect reduction is this
IM pin reduction
what type of indirect reduction is this
indirect reduction using animals weight in tibial/radial fractures
Briefly describe how to do an indirect reduction using animals weight
hang the leg, drop the sx table down and when fracture is stabilized you can raise the table
what are the 8 steps of fracture treatment planning
- determine FAS
- choose appropriate implant system
- select technique for fracture reduction
- develop plan for applying implants
- decide about using bone grafts
- surgical approach or approaches selected
- check implant and instrument inventory
- precontour plate (if needed)
T/F: When developing a plan for applying implants, we should make a drawing of fracture bone and the implant before sx
true! Helps ensure optimal results
what is important to do after sx when we use implants
evaluate postoperative radiographs to make sure the outcome you wanted is there
what are the 5 types of bone grafts
- autograft
- allograft
- biomaterials
- synthetic bone substitutes
- composites of osteogenic cells
what is an autograft
bone transplanted from one sit to another in same animal
what is an allograft
bone transplanted from one animal to another of same species
what is a biomaterials graft
demineralized bone matrix, collagen
what is a synthetic bone substitute
tricalcium phosphate ceramics, bioglass and polymers
what is a composite of osteogenic cell graft
osteoinductive growth fractures and synthetic osteoconductive matrix
what are the “4 O’s” of graphs
- osteogenesis
- osteoinduction
- osteoconduction
- osteopromotion
what is osteogenesis
ability of cells to survive transplantation and serve as source of osteoblasts
what is osteoinduction
ability of material to induce migration and differentiation of mesenchymal stem cells into osteoblasts (VIA BMP - bone morphogenetic protein)
what is osteoconduction
ability of material to provide scaffold for host bone invasion and determines speed of osteointegration
what is osteopromotion
material that enhances regeneration of bone (like PRP - platelet rich plasma)
what type of bone grafts are considered gold standard
cancellous bone autographs
what are the advantages of cancellous bone autografts
- recommended when rapid bone formation is desired
- assist healing when optimal healing not anticipated
- promote bone formation in infected fractures
what are the disadvantages of cancellous bone autographs
- additional surgical time required to harvest graft
- potential for morbidity associated with donor site
- limited availability of cancellous bone in small or elderly patients
where are the best sites for cancellous bone autografts
proximal humerus, proximal tibia, ilial wing, and distal femur
T/F: Cancellous bone autografts are harvested prior to fracture stabilization
FALSE! harvested after fracture stabilization but BEFORE primary ortho procedure
what is this image showing
how to take a graft of proximal humerus
what is this image showing
ilial wing bone graft
where are cortical bone autografts harvested
ribs, ilial wing, distal ulna, and fibula
what is a segmental graft
placed between fracture segments
what is a sliding onlay graft
paced over fracture site
what are the 3 advantages of cancellous bone allografts
- reduced operating time
- availability of graft
- elimination of morbidity at donor site
what are the disadvantages of cancellous bone allografts
- cost of grafts
- lack of osteogenic properties in cancellous bone chips
T/F: Autogenous grafts are superior to allogenic grafts in promoting rapid new bone formation
true! Due to osteogenic properties
why are cortical bone allografts harvested and banked
to provide a ready source of cortical alloimplants
T/F: Cortical bone allografts are commonly used in fracture repairs
FALSE rarely used in fx repair……used for limb-sparing procedures
what is demineralized bone matrix
it is from processed allograft bone available for dogs and cats
what are the 4 types of fracture fixation systems
- external coaptation
- external skeletal fixators
- intramedullary fixation
- plate and screw fixation
what is the purpose of external coaptation
provides patient comfort before or after sx and can be used as primary repair in some conditions
what is important to remember about external coaptation as primary fixation
for bone to heal, MUST be at least 50% reduction of segments at fracture site on 2 radiographic views
what are the 3 types of external coaptation
- bandages
- splints
- casts
what is important to remember about full leg casts
- cant apply above midhumerus or midfemur
- used ONLY for fractures of distal limb
what is important to remember about bivalve casts
- supplements internal fixation devices
- used for fxs of carpus, tarsus, metacarpal/metatarsal bones & digits, or carpal or tarsal arthrodesis
