Posterior Tibial Tendon Dysfunction -Frush Flashcards
main attachment posterior tibial tendon (PTT)
navicular tuberosity
attaches to almost every bone (every tarsal except talus and not 1st and 5th met)
most powerful supinator of foot
posterior tibial
- has weak plantarflexion capabilities
spring ligament =
- superomedial and inferior calcaneal navicular ligament
- PTT passes superficial to ligament and has articulation with it
where is zone of hypovascularity of PTT
1-1.5 cm distal to medial malleolus
* most common area for PTT dysfunction
function of PT in gait
- supporter of longitudinal arch
- decelerates leg internal rotation by eccentric contraction
- during midstance concentric contraction (STJ supination)
what happens biomechanically if PTT dysfunctional?
- can’t prevent excessive pronation
- talar head puts strain on spring ligament causing attenuation
- as arch collapses, deltoid strain can cause ankle valgus
foot types that predispose to degenerative PTT
obesity equinus calcaneal valgus pes planus accessory navicular
typical degenerative PTT pt
over 40, female
s/s PTT dysfunction
- pain and swelling in medial ankle/midfoot
- loss of medial arch
- tendency to walk on inner border of foot
- loss of push off/strength
- pain on lateral aspect with impingement b/w lateral ankle and calcaneus
PE PTT dysfunction
- edema along PTT course
- pain with palpation at navicular insertion and hypovascular area
- may have increased warmth if acutely inflamed
“too many toes sign”
pt standing, look from behind and see more toes on affected side
single heel rise test
pt stands on one foot and attempts to rise up on toes
- pain, unable, heel doesn’t invert could indicate PTT dysfunction
- do double heel rise first
how do you test for posterior tibial m strength
- place foot in plantarflexed and inverted position
- pt holds position against resistance
- evaluate for pain and/or weakness
what type of forefoot position does the pt likely have?
forefoot varus
kite’s angle
talocalcaneal angle (17-21)
cuboid abduction angle
less than 5
talar head uncoverage
percentage of talar head uncovered by navicular
normal is less than 20%
what do you look for on AP ankle
arthritic changes
valgus deformity
normal values and increase or decrease with PTT dysfunction:
calc. inclination
talar declination
meary’s angle (bisection talus and 1st met)t
alocalcaneal
18-21 decrease
21 increase
0-10 increase
15-35 increase
normal rearfoot alignment
0 - 10mm
normal tibial-calcaneal
0-2 valgus
PTTD staging
johnson and strom
johnson and strom I
- peritendinitis/tenosynovitis
- flexible/normal rearfoot
- mild weakness with heel rise
- too many toes sign negative
- synovial proliferation/ mild degeneration
- conservative tx 3 mo/ tenosynovectomy with tendon debridement if necessary
johnson and strom II
- elongated tendon
- flexible/valgus rearfoot
- marked heel rise weakness
- positive too many toes
- marked degeneration
- tx with flexor digitorum transfer/ rearfoot arthodesis/ osteotomies
