wk 4- diabetes and biomechanics Flashcards
complications of diabetes
PVD
neuropathy (somatic and autonomic)
foot ulceration how does it happen
neuropathy
foot deformity
trauma
ulceration
autonomic neuropathy in patient history
orthostatic hypotension
constipation/diarrheaa
sweating while eating
increased sweating in hands
dry skin, eyes, mouth
warm foot
rubor- red
bounding pulses
poor balance
how much force needed to penetrate nromal intact tissue
100kg/cm2
mechanism of foot injury
- high force over a small area (standing on an object)
- low pressure for a long period of time (tight footwear)
- repeated moderate stress (walking)
viscoelasticity
allows soft tissue to adapt to stress
viscous- moulds to applied stress by increasing surface area of contact which decreases pressure
elastic- soft tissue absorbs energy and return it to the environment via elastic recoil
a reduction in either of these areas means it has less resistance to break down
the difference between normal tissue and diabetic tissue
diabetic has less viscoelastic tissue due to non enzymatic glycosylation of connective tissue proteins in the skin
and therefore a smaller safety margin to tissue breakdown.
what happens to the skin after a healed ulcer
scar tissue thick/stiffer skin) and decreased tissue thicknesss
for this reason, reulcerating is common
plantar fascia and achillies in diabetes
thickening can occur which causes the foot to become more rigid during gait and increases force in the foot, specifically under the metatarsals
in diabetes what muscle changes are being seen
anterior muscle groups weaken and the posterior muscle groups gain mechanical advantage
increased plantarflexion and reduced ankle ROM which increases forefoot pressures
generalised limitation of joint mobility
reduction in mobility due to the change in collagen for diabetics
typically seen at the ankle, stj and 1stmtpj
decrease range in what joint is a significant risk factor for ulceration
STJ
trigger finger in diabetics shows an increased risk of what
CVD
callous debridement in diabetics reduces pressure by
30%
methods of pressure relief
padding and strapping - temporary
total non-weight bearing -muscle wasting
shoe mods/rocker- can increase pressures if not in right area
-total contact casting- not in infection
when is an achilles tendon lengthening indicated
diabetic neuropathic plantar met head ulcer when all other offloading treatments fail. (mod recommendation)
when is a met head resection indicated
diabetic neuropathic plantar met head ulcer where offloading treatments fail (low recommendation)
when is a digital flexor tenotomy indicated
diabetic neuropathic plantar or apex ulcer on digits 2-5 when offloading has failed (moderate recommendation)
wound healing
- inflammatory phase
- proliferative phase
3 remodeling phase
impaired wound healing caused by (2)
- excess matrix metalloproteinases
-degrade new tissue through exudate, slough, debris - impaired blood vessel network
-hypoxia and defective micronutrient delivery
4 components of wound hygeine
- cleanse
- debride
- refashion - wound edge/ peri wound
- dress
what does biofilm on a wound do
increases the duration of wound healing as it is bacteria that covers the wound bed
this causes subclinical signs of infection (exudate, slough, erythema) and stops dressings from contacting the wound bed
how long for biofilm to form
within hours and reach maturity in 2-3days
biolfilm is present in how many DFU
68-100%
