Maxillofacial Trauma 1 Flashcards
inflammatory reparative remodeling occurs within ___ hours of the injury, and begins within___
48 hours, begins immediately, lasts 2-4 weeks
what is procallus formation
- neovascularization from periosteum -> hematoma
- granular tissue within hematoma
what is soft callus formation
- bone morphogenic proteins attract bone forming cells
- collagen + procallus = soft callus
- soft callus forms the outer shell around the fracture (cartilaginous phase)
- timing: 2-8 weeks after injury, can take up to 3-4 weeks
what is hard / bony callus formation
- when new bone is deposited
- timing: 4-8 wks after injury, can take 3-4 mos
- hard callus = new mineralized woven bone visible on x-ray
what is medullary bridging callus
- happens to all bones
- osteoclasts migrate to the area to eat away excess bone based on function
- continuous remodeling
- timing: years
3 types of osseous callus
- periosteal bridging callus: external callus
- medullary bridging callus: wholly within the bone medulla
- intercortical uniting callus: bridges cortices of the bone fragments
timeline of bone healing
- 12 hrs: bleeding stops, clots in site
- day 1: local acute inflammation
- day 2: early granulation tissue formation
- day 5: earliest osteogenesis
- 3 wks: fibrous union and patchy callus
- 6 wks: continuity of external callus
- 4 mos: remodeling completed
t/f calluses form to “splint” the bone
true
t/f granulation tissue is able to withstand 100% strain, cartilage 15%, and bone 2%
true
t/f in the most stable of repairs, we can skip all immediate tissue types and progress to direct bone formation
true, no callus formation
requirements for primary bone healing
- bones are apposed against each other and held immobile
- can be done through surgical fixation
- bridging callouses are formed by bridging osteons (cutter cones)
what happens in secondary bone healing
- there is a gap between fractured segments
- the body forms a callus across the gap
- bone without blood supply dies back
- torn vessels form a hematoma
- fibroblasts transform hematoma into granulation tissue (fibrin meshwork)
means of stabilization in primary vs secondary bone healing
primary: plates or wires
secondary: external splinting
means of healing in primary vs secondary bone healing
primary: contact or gap healing
secondary: callus formation
means of bony fusion in primary vs secondary bone healing
primary: cutting cones and osteons
secondary: bone formation by osteocytes
hormones that have a negative effect on bone healing
cortisone (steroids): decrease callus formation
hormones that have positive effect on bone healing
calcitonin
thyroid and pth: enhances bone remodeling
gh: increases callus volume
androgens: increase callus volume
factors that adversely affect bone healing
- excessive damage to surrounding tissue
- excessive motion at site
- tissue interposition
- distraction of bone ends (too far)
- acute/chronic osteomyelitis
- preexisting local blood supply anomalies (diabetes)
- vitamin deficiencies
- exogenous steroids
- advanced age
- osteoporosis
a condition wherein the fractured ends have healed in a faulty bony union
malunion
bones which are slow to heal after an average period wherein a similar fracture would have been expected to heal
delayed union
- a terminal condition of failed osteogenesis where the bone is still mobile but normally wouldn’t be
- radiological evidence of a progressive decrease in radiolucency at the site
- presence of histologically identifiable osteogenic tissue
non-union
principles of debridement
- use a stiff scrub brush and surgical soap to clean
- irrigate with saline to remove debris (d5w has hemostatic effects)
- curette or scalpel blade to remove gravel or bitumen
- water jet lavage in blast type injuries
- palpate wound for foreign bodies
- polymixin b sulfate to remove residual grease
- final flushing with h2o2
methods for hemostasis
- warm pressure packs: induces hypotension for hypovolemic or normovolemic
- direct care of the vessel
methods of direct care for the vessel
- direct ligation (suture material)
- electrocoagulation (cautery)
- clips
- ligation below the bleeder
t/f arterial hemorrhages are more problematic than venous
false, venous is more problematic
what is undermining
- lifting the skin from the underlying tissue to stretch it enough to approximate the wound you are covering
- necessary for large defects without excessive tension on soft tissues
suturing techniques for primary closure
- simple interrupted
- mattress sutures (horizontal or vertical)
- continuous running suture
- running interlocking suture
sutures that affect water tight closure
running interlocking and running horizontal (most watertight)
best suture for the oral cavity
silk: does not stretch and does not loosen
in primary closure, layers are closed from ___ to __
from deep to superficial
sutures for subcutaneous area and skin
sc: inverted sutures or inverted t sutures
skin: nylon 5-0, subcuticular continuous suture
types of material for sutures
- polygenic acid or silk (remains in place)
- plain catgut (loosens, better for oral)
- chromic catgut (causes irritation and wound breakdown)
types of sutures/material for skin
- 5-0 nylon or polyethelene sutures for skin closure
- 6-0 interrupted sutures to evert the wound
- continuous lock sutures to decrease operating time
uses of delayed primary closure
- contaminated wound
- first managed >48h after injury
- large volume of patients
steps of delayed primary closure
- debridement
- dress it open with moist fine mesh and antiseptic gauze
- give antibiotics, clean regularly
- close in 3-5 days
uses of secondary closure
- warfare or terrorist attack (large number of patients)
- specific treatment is given >5 d from injury (infection)
steps of secondary closure
- remove infected tissue, debride everyday
- drain
- moist dressing
- antibiotics
- close after >5 d
when is drain not required
- superficial lacerations
- wounds above the mandible
indications for drain
- missile injuries (bullets and blasts)
- wounds below the mandible: floor of mouth, base of tongue, retromandibular area, infratemporal fossa, neck
types of drains
negative pressure: sucks out fluid
ordinary: no suction
steps in draining a wound
- insert drain between sutures
- suture to the skin edge
- remove drain in 2-5 days when there is no purulent exudate
- tie sutures
general instructions for injuries
simple lacerations: adhesive strips
complex lacerations: compressive dressings (prevents postop edema, reduces tension, immobilizes wound)
dressing regimen
read
post-op care
read
cdc classification of surgical wounds
read
class 1: clean class 2: clean contaminated class 3: contaminated class 4: infected or dirty
management for contusions
- antibiotics not necessary
- cold compress for first 24 hrs, 10-15 mins every hr
complications in hematoma
ear and nasal septum: cauliflower ear or saddle nose deformity
periorbital hematoma: ecchymosis (less swelling and blood is being absorbed)
management for hematoma
- yes antibiotics
- ear and nasal septum: incise and drain, provide compressive continusous dressing for 3 days
- needle aspiration not recommended
general management for abrasions
- clean with saline or mild soap
- leave exposed
- lightly dress with bacitracin
specific management for abrasions
ordinary abrasions: spontaneous healing (weeks)
abrasions with tattooing potential (due to gravel or asphals): vigorous scrubbing, mechanical abraders with carbide tip
most common type of injury in vehicular accidents
simple lacerations
general management for simple lacerations
- clean, irrigate, excise devitalized tissue, hemostasis, suture, dress
- face: conservation of skin is important
- always use fine sutures
techniques in treatment for simple lacerations
- vicryl or dexon to close deep lacerations
- nylon 5-0 or 6-0
- steristrips to immobilize the wound
- remove sutures in 3-5 d
t/f alignment during lip suturing is not necessary
false, must align because its obvious when its not
what are puncture wounds
wounds that go through the body
management of simple small avulsions
excise as an ellipse -> undermine -> close
management of multiple small flaps
tacky technique with nylon -> pressure dressing -> dermabrade later
management of large flaps
- excise edges to produce a perpendicular edge -> undermine -> close -> z plasty later
- important to cut off the edge so that there is better healing
management for large defects with guarded prognosis, not amenable to full thickness grafting
apply thin split thickness skin graft -> local or regional flaps when the infection is reduced
management of avulsion in nose, lip and ear
- use the avulsed tissue
- clean with saline soln and suture as composite graft
management of big “clean” defects
full thickness skin graft from nearby source
most bites are caused by ___
dogs
t/f human bites are more dangerous
true, they deliver streptococci, staphylococci, fusiform bacilli, and spirochetes
bites on the extremities can have ___, and on the face ___
extremities can have secondary healing, on the face secondary healing is discouraged
management of bites on the face
- clean vigorously with a high powered jet irrigator
- primary closure (close wound over a drain if <8 h old)
- administer broad spectrum antibiotics
- open the wound if infection happens
t/f reattachments of soft tissue that has been avulsed by an animal or human bite can be successful
false, doomed to failure
clinical manifestations of rabies
aggressive behavior, muscle spasm and convulsion, anxiety and restlessness, hypersalivation
management for rabies
- rabies post-exposure prophylaxis
- immediately wash and flush with soap and water for 15 min
- administer antibiotics
- administer tetanus prophylaxis
- 20 iu/kg human or equine rabies (hrig/erig) in category 3 exposure
t/f patients with rabies actually have hydrophobia
false, they have a fear of swallowing water and aspiration (due to encephalitis)
categories of rabies exposure
category 1: touching or feeding, lick NO PROPHYLAXIIS
category 2: minor scratches or abrasions without bleeding or nibbling VACCINE ONLY
category 3: transdermal bites, scratches, licks on broken skin IG AND VACCINE
a low velocity missile retained within the tissue ( + entrance wound, - exit wound)
penetrating
missile that passes through the tissue (+ entrance wound, + exit wound)
perforating
- high velocity = large avulsed exit wounds
injuries related to high velocity missiles in which portions of tissues are completely removed from the patients
avulsive
dirt or other foreign body particles penetrate the tissues -> shredding of tissues
blast injuries
- difficult to clean
- tattooing is inevitable
- infection frequent
resulting injury from a .45 caliber full metal jacket
penetrates and passes through body
resulting injury from a .45 caliber hollow point
bigger cavitation compared to the full metal
resulting injury from 5.56x45 mm
entry and exit wound, lots of kinetic energy that damages soft tissue (causes more damage than .45)
t/f the bigger the bullet, the bigger the injury
true
other aspects of bullet wounds
wobble and tumble due to poor rifling of the barrel
size, weight, shape
complications from gunshot injuries
tissue loss due to consecutive debridements
classification of facial nerve injuries
behind lateral canthus: can be repaired
medial to vertical line: no hope looking for it
management of facial nerve injuries
- aim for exact end to end fascicular anastomosis
- 10-0 for large nerve sections
- use cable grafting for nerves that cannot be primarily repaired
- return of function is in 4-5 mos
lacerations along ___ should be evaluated for parotid duct injuries
parotid duct line
management of parotid duct injuries
- examine
- cannulate with polyethylene tube
- advance tube under direct vision
- cannulate proximal end
- suture duct walls together (6-0)
- suture the end of tubing to buccal mucosa intraorally and tape to cheek externally
- remove in 7-10 d
management of salivary gland injuries
- submandiibular glands need to be removed
- after repair of parotid gland, weeping of saliva may happen
- heals within 2 wks
- maintian pressure dressing
