3-Rearfoot Valgus Flashcards
1
Q
rearfoot valgus:
define
A
- frontal plane deformity
- calcaneus is EVERTED relative to the floor at heel strike
2
Q
at what age range is rearfoot valgus commonly seen?
is it always pathologic?
A
Seen in early childhood development with subsequent development of equinus due to valgus ankle
(not always pathologic in pediatric phase)
3
Q
list the etiologies of REARFOOT VALGUS:
from proximal to distal
A
- coxa vara/ genu valgum
- genu valgum
- tibial valgum
- ankle valgum
- STJ valgum
- calcaneovalgus (triplanar, flexible flatfoot)
-
tarsal coalition (one of the most common causes)
- calcaneonavicular (most common)
- talocalcaneus
4
Q
coxa vara/ genu valgum:
layman’s terms, etiology, and clinical presentation
A
- “knock-kneed”
- etiology:
- developmental abnormalities
- internal femoral torsion
- elderly patients w/ arthritis
- clinical presentation:
- REARFOOT VALGUS
- flatfoot
- wide base of gait
- significant LATERAL CREASING of dorsal and lateral foot
5
Q
ankle valgus:
etiology, structure, foot deformity
A
- etiology:
- deformed or fractured fibula
- premature closure of the fibular epiphysis
- fibular hemimelia/agenesis
- tibial pathology (fx, premature closure of lateral distal tibial epiphysis)
- structure:
- fibula bears 20% of weight, acting as lateral strut/ support for ankle joint
- if fibular pathology –> the ankle will shift into valgus
- deformity: –> produces rearfoot valgus at STJ
6
Q
rearfoot valgus:
movement re: calcaneus, leg, STJ, MTJ
A
- calcaneus strikes EVERTED w/ no mechanism to invert –>
- leg is internally rotating (IR)
- normal body weight and IR of leg –> needed/normal pronation for gait
- striking everted leads to severe pronation and symptoms
- STJ maximally PRONATES and unlocks MTJ –> collapse of medial arch & flatfoot
- as ground rxn force pushes up on medial forefoot –> significant inversion (rotation) about longitudinal axis of MTJ –>
- brings lateral forefoot to the ground
- results in forefoot supinatus (*not varus)
7
Q
supinatus vs. forefoot varus
(what’s the difference(s)?)
A
-
supinatus:
- soft tissue deformity
- triplane
-
forefoot varus:
- fixed, osseous deformity of frontal plane
- frontal plane
8
Q
supinatus is maintained by, and how much inversion?
A
- Maintained by TA tendon –> dramatic effect on first ray/medial column
- Results in as much as 20 degrees of forefoot inversion relative to the
rearfoot (compensatory deformity)
9
Q
forefoot varus:
FF relative to RF, and etiology
A
- Forefoot is inverted relative to the rearfoot
- Ontogenetic/result of abnormal frontal plane development of the head/neck of the talus relative to the body
- (ontogenetic: origin/development of organism; from time of fertilization –> mature form)
10
Q
rearfoot valgus:
clinical presentation (foot structure)
A
-
Medial buldge
- talar head and navicular tuberosity protrude MEDIALLY
- due to transverse plane dominance of the oblique MTJ
- ABduction of foot w/ added ABduction of FF on RF
-
Longitudinal arch drops
- due to motion in sagittal plane around oblique MTJ
-
Medial column rotates at TNJ –> too many toes sign
- due to frontal plane motion at longitudinal MTJ leading to supinatus
- **Reverse arch forms
11
Q
characteristic sign of rearfoot VALGUS
A
too many toes sign
(over pronation or posterior tibial tendon insufficiency)
12
Q
rearfoot valgus:
sxs beyond foot deformity
A
-
Callus
- hallux IPJ pinch callus due to rolling off mechanism
- possibly submet 2 callus due to hypermobility of 1st ray
- ADductovarus 5th digit w/ dorsolateral corn
- Medial heel wear on shoes
- Lateral shift of calcaneal fat pad –> medial heel pain, and calcaneal apophysitis (kids)
- Hallux abductovalgus (HAV/bunion) <– excess pronation
13
Q
rearfoot varus:
postural, sinus tarsi, foot position sxs
A
-
Postural sxs <– due to instability
- unable to do single/double heel raise
-
Sinus tarsi sxs <– secondary to lateral pinching
- pain during attempted supination <– peroneus brevis is tight/contracted/in spasm
- (peroneal spastic flatfoot (peroneus brevis, NOT LONGUS)
- if present in children, likely tarsal coalition
- (possibly HL/HR) <– Equinus <– limited DF <– contracture of Achille’s (due to pronation)
14
Q
rearfoot valgus:
evaluation
A
-
single/double heel raise
- this mimics propulsion
- NEGATIVE/NORMAL - calcaneus should INVERT
- POSITIVE/abnormal - calcaneus EVERTED/ABducted, FF is INVERTED relative to RF during supinatus
- if it does not invert –> indicative of peroneus tertius rupture/ disease OR rearfoot valgus
15
Q
ankle valgus:
tx
A
*CANNOT BE TREATED W/ AN ORTHOTIC
- Consider wedge osteotomy of the tibia (medial base)
- inverts tibial plafond into neutral position
-
Epiphysiodesis in peds pts w/ open tibial growth plates
- staple across distal medial tibial epiphysis to stop growth medially while allowing the lateral aspect to grow
- REBALANCE joint position
-
MAFO (molded ankle-foot orthosis) holds foot in alignment w/ leg
- imparts STJ stability; but has potential to cause medial ulcerations
- medial ulcerations result depending on degree of deformity and for diabetic patients (who may have decreased sensation and may not detect the irritation)
