Foot & Ankle Flashcards
Toe off during terminal stance
Posterior tibialis fires causing subtalar inversion, which locks transverse tarsal joints, stabilizing hindfoot/midfoot for push off.
**Posterior tibialis is most important during terminal stance.
Heel strike (early stance)
subtalar eversion unlocks transverse tarsal joints –> supple foot acts as shock asbsorber
During the gait cycle, the anterior tibialis eccentrically contracts as…
ankle plantarflexes, then concentrically contracts as the ankle dorsiflexes.
Quadriceps weakness will cause…
knee hyperextension during swing phase.
Weakness of hip flexors affects..
limb advancement during swing phase.
Risk of anterolateral portal during ankle arthroscopy
SPN
Risk of anteromedial portal during ankle arthroscopy
saphenous nerve and vein
Better healing of ulcers is associated with:
- albumin > 3
- ABI >.45
- lymphocyte count > 1500
- toe pressure > 40
- transcutaneous oxygen tension > 30
Treatment of chronic plantar ulcer at the IP joint of the hallux if no sign of infection
Keller arthroplasty
Treatment of chronic heel ulcer unresponsive to serial debridement, that probes to bone or osteomyelitis on MRI
Adequate perfusion: calcaneal saucerization & TAL
Inadequate perfusion: BKA
In charcot arthropathy, limb elevation will…
reduce hyperemia (not true in infection)
Pathophysiology of charcot arthropathy
bone destruction is due to hypervascularity
Advanced imaging of charcot arthropathy
-technetium bone scan: positive for charcot and infection
indium WBC scan: positive for infection ONLY
Initial tx of Charcot
total contact casting then transition to CROW boot
Hallux valgus deformity
Hallux is plantarflexed, pronated and in valgus
Normal hallux angles
HVA < 15
IMA < 9
DMAA < 10
Treatment for HVA < 40 and IMA < 13
distal MT osteotomy
Treatment for HVA > 40 and IMA > 13
proximal MT osteotomy or combined proximal/distal osteotomies
If there is increased DMAA, need to treat with…
combined proximal and distal MT osteotomies.
Instability of the 1st TMT is characterized by…
medial translation and plantar gapping of 1st TMTJ on xrays.
What nerve is at risk with hallux valgus surgery?
Dorsomedial cutaneous nerve (branch of SPN)
Modified McBride procedure includes…
release of adductor hallucis to help correct the deformity.
Treatment of hallux valgus interphalangeus
Akin (proximal phalanx) osteotomy
Treatment of hallux valgus in pts with neuromuscular conditions
MTP fusion
Excessive resection of the medial eminence can lead to…
iatrogenic hallux varus
Treatment of juvenile/adolescent hallux valgus
open physis so perform medial cuneiform osteotomy rather than MT osteotomy
Treatment of mild hallux rigidus (pain only with terminal dorsiflexion)
dorsal cheilectomy
dorsiflexion is what is most limited in hallux rigidus
Type I Bunionette
enlarged 5th MT head +/- lateral exostosis
Tx: exostectomy of 5th MT head
Type II Bunionette
lateral bowing of 5th MT
Tx: distal chevron osteotomy
Type III Bunionette
widened 4,5 IMA > 12
Tx: rotational diaphyseal osteotomy
Pathophysiology of cavovarus foot
Peroneus longus overpowers tibialis anterior (predominant force) –> cavus
Posterior tibialis overpowers peroneus brevis –> varus
Initial deformity of cavovarus foot is..
plantarflexion of 1st ray.
Treatment of flexible cavovarus
plantar fascia release, PT transfer to dorsum of foot, PL transfer
Treatment of rigid cavovarus
lateralizing calc osteotomy
Treatment of pediatric flexible flatfoot if fails non-op…
varus producing calc osteotomy (lengthening or medializing)
Lateral impaction syndrome
subluxation of the talocalcaneal joint in flatfoot –> impingement between the talus and calcaneus in the sinus tarsi and/or distal fibula and calc
Stage I PTTI
no deformity, able to perform single heel raise
normal xray
Stage II PTTI
flexible planovalgus, unable to perform single limb heel raise
x-rays: flatfoot
tx: FDL transfer to augment PT, medializing calc osteotomy or lateral column lengthening)
Stage III PTTI
rigid planovalgus
x-rays: subtalar arthritis
tx: triple arthrodesis
Stage IV PTTI
rigid planovalgus
x-rays: talar tilt
tx: TTC arthrodesis
Management of residual forefoot varus deformity in planovalgus is due to…
malposition of the transverse tarsal joint and is treated with dorsal opening plantarflexion osteotomy of the medial cuneiform (Cotton).
Way to reduce infection in treatment of planovalgus
perform subtalar and talonavicular arthrodesis through single medial approach
Treatment of acquired flatfoot deformity in those with midfoot arthritis/instability and normal PT function (small subset)
midfoot arthrodesis and TAL
What nerve is at greatest risk with a TCC fusion with IMN
lateral plantar nerve
Spastic equinovarus is usually due to…
stroke or TBI –> spastic GSC causes equinus and spastic tib ant causes varus
*If non-op (AFO) fails –> TAL and SPLATT to cuboid
The interdigital nerve runs…
below the transverse intermetatarsal ligament.
Treatment of Morton’s neuroma
Non-op: wide shoe box, MT pad, injection
Op: dorsal neurectomy
In Morton’s neuroma, multiple cortisone injections can lead to…
hammertoe deformity.
Histology of Morton’s neuroma
perineural fibrosis
Deficiency of the plantar plate can lead to…
cross-over toe deformity
2nd MTP synovitis
- walking on a “marble”
- callus under 2nd MT head
- subluxation w/ drawer test (dorsal subluxation of MTP joint)
Initial tx of 2nd MTP synovitis
MT pad
Tx of fixed dorsal MTP dislocation
distal oblique MT shortening osteotomy (Weil)
Hammertoe
overpull of EDL and contracture of FDL –> PIP flexion and DIP extension
tx: flexible –> FDL to EDL transfer
rigid –> PIP resection arthroplasty
Mallet toe
DIP hyperflexion from FDL contracture
tx: flexible –> FDL to EDL transfer
rigid –> DIP fusion or resection arthroplasty
Claw toe
intrinsic minus foot deformity: MTP hyperextension, PIP/DIP flexion
usually due to MTP synovitis and attenuation of the plantar plate
Treatment of claw toe
non-op: taping
op:
flexible –> EDB tentomy, EDL lengthening, FDL to extensor trasnfer
rigid: resection arhtorplasty of proximal phalanx or weil osteotomy
Most common complication of Weil osteotomy is…
floating toe (dorsiflexion deformity of MTP)
Turf toe
hyperextension injury of 1st MTP joint resulting in injury to the plantar plate and sesamoid complex
Tx with taping (or repair in an athlete)
Imaging for turf toe
Weight bearing or forced dorsiflexion x-rays but if too painful can get MRI
The sesamoids are embedded in the…
FHB tendon.
Tibial sesamoidectomy can lead to…
hallux valgus deformity.
Fibular sesamoidectomy can lead to…
hallux varus deformity.
Sesamoidectomy of both can lead to…
cock up hallux due to FHB weakness.
Treatment of Kohler dz (AVN of the naviuclar)
immobilization in short leg walking cast
Baxter neuropraxia (1st branch of lateral plantar nerve)
Symptoms: pain in plantar medial heel and base of 5th MT
Overview: innervates abductor digit quinti; compression between abductor hallucis longus and quadratus plantae
Tx: release fascia of AHL
Plantar fasciitis
Symptoms: tight GSC, TTP over medial process of calc tuberosity
Overview: pain is worse when getting out of bed, better after a few steps and worse again at end of day; BMI > 30 is risk factor
Tx: eccentric stretching of plantar fascia & achilles, night splint, shock wave, plantar fasciotomy/TAL
Tarsal tunnel syndrome
Exam: tinel sign with percussion of tibial nerve
overview: paresthesias in plantar foot with compression of tunnel
tx: if fails non-op, tarsal tunnel release
anterior tarsal tunnel syndrome
entrapment of the DPN at the level of the inferior extensor retinaculum –> pain/paresthesias in 1st webspace; tenderness to palaption over 1st and 2nd MT bases
*Often due to tight shoe/ski boot
**If fails non-op, treat with inferior extensor retinaculum release.
For achilles tendinosis, if > 50% of the achilles insertion or tendon is debrided, then…
augment with FHL or FDL transfer.
Tx of achilles tendinosis w/ chronic attritional rupture
calc ostectomy & insertional repair
After achilles rupture tx, early motion will…
decrease rerupture rate.
Treatment of chronic achilles rupture w/ gap > 5 cm
gastroc turndown reconstruction +/- FHL tendon transfer.
Posterior ankle arthroscopy puts what nerve at risk?
sural
Most common tarsal coalition
calcaneonavicular
Approach for tarsal coalition excision
calcaneonavicular: lateral incision over sinus tarsi
talocalcaneal: medial incision between FDL/FHL
In a high ankle sprain, the initial ligament to be injured is…
AITFL
ATFL sprain
injured during plantarflexion and inversion
laxity to anterior drawer testing in plantarflexion
CFL sprain
injured during dorsiflexion and inversion
laxity to anterior drawer test in dorsiflexion
Osteochondral lesion of the talus, lateral lesions are…
usually traumatic and less common.
SPR is injured with…
forced ankle dorsiflexion and inversion
SPR apprehension test
subluxation w/ ankle dorsiflexed and everted
Treatment of peroneal tendon tears
small: debride, core repair and tubularzie
large irreparable one tendon: tenodesis to intact tendon
large irreparable both tendons: FHL transfer or allograft reconstruction
Allograft reconstruction of peroneal tendon tear requires…
proximal muscle excursion.
Fusion angle for ankle
5-10 degrees ER
5 degrees valgus
neutral dorsiflexion
Total ankle replacement increases…
stride length, cadence and velocity compared to fusion.
