2-Rearfoot Varus Flashcards
1
Q
trendelenburg gait:
define
A
- hip ABductors (gluteus MED/MIN) are not working properly
- trunk LEAN TO the same side as the hip pathology (ipsilateral lean); meaning the lesion is on the contralateral side
- https://www.youtube.com/watch?v=Rz7V1i8kYGU
2
Q
ataxic gait:
define
A
- the presence of abnormal, “jerky”, uncoordinated movements
- wide base of gait
- aka “drunken sailor gait”
- caused by upper motor neurons
https://www.youtube.com/watch?v=020YoEy4eLA
3
Q
High Steppage/ Foot slap gait:
define
A
- patient compensates by lifting affected foot higher than normal;
- caused by (common peroneal nerve palsy –> can’t control anterior compartment group –> can’t dorsiflex their foot) –> causes foot drop due to inability to dorsiflex the foot
https://www.youtube.com/watch?v=jzJIpY6vRLo
4
Q
circumductive gait:
define
A
- patient abducts her thigh and swings her leg in a semi-circle to attain adequate clearance for foot
- unable to achieve adequate clearance for the foot to move through the swing phase on the affected side
- causes incl: probs w/ hip/knee flexion or ankle dorsiflexion
https://www.youtube.com/watch?v=Q98WKpwIpkE&t=39s
5
Q
calcaneal gait/ triceps surae gait:
define
A
- characterized by walking on the heel –> high contact pressure on heel
- due to paralysis of the calf muscles –> overcompensation of anterior compartment (abnormal firing)
- caused by poliomyelitis and in some other neurologic diseases
6
Q
What are following abbreviations:
STJ
MTJ
STJNP
RCSP
NCSP
A
7
Q
relaxed calcaneal stance position (RCSP):
define
A
position of calcaneus relative to ground after all compensation has occurred
8
Q
neutral calcaneal stance position (NCSP):
define
A
position of calcaneus relative to the ground when STJ is in neutral position
**neutral does not necessarily mean parallel or perpendicular
9
Q
From subtalar joint neutral position,
how much inversion/eversion?
A
twice as much supination/inversion of foot as pronation/eversion
(2:1 ratio)
2 degrees supination - 1 degree pronation
10
Q
what is the ideal position of the foot in subtalar joint neutral position?
A
foot is NEITHER pronated NOR supinated
11
Q
what is the relationship of forefoot and rearfoot when foot is:
in STJNP w/ the MTJ maximally pronated and locked?
A
when in this pronated position:
- the forefoot to rearfoot should be perpendicular;
- w/ mets 1-5 perpendicular to bisection of posterior calcaneus
12
Q
in normal foot w/ STJNP with MTJ maximally pronated and locked;
how much ankle dorsiflexion should there be with the knee extended?
A
- You must have 10 degrees of DF of the foot relative to the leg with the knee extended.
- This measurement mimics the position that occurs at 50-60% of stance phase, right before heel off
13
Q
Which plane influence that could cause hyperpronation of the foot?
A
None!
There is no significant transverse or frontal plane influence on the foot from
the leg that would cause significant hyper-pronation
14
Q
Which plane determines the position of the calcaneus at heel strike?
A
• Frontal plane development of the foot and leg determines the position of the
calcaneus at heel strike
15
Q
**angle at which “normal foot” strikes the ground?
why?
A
- “normal” foot strikes the ground 2-3 degrees inverted
- **because the STJ is supinated
16
Q
how to calculate STJNP?
A
STJNP = (TROM/3) – eversion
e.g.
25 degrees inversion, 5 degrees eversion: (30/3) – 5 = 5 degrees
inverted
17
Q
*how to calculate available motion?
A
Available Motion = (TROM/3)
e.g.
- 25 inversion, 5 eversion, STJNP 5 inverted, 5 tibial varum
- Foot is contacting ground at 10 inverted (STJNP + tibial)
- Total motion available = (TROM/3) = 10 (so this patient would be able to fully compensate for their RF varus)
18
Q
how to evaluate forefoot to rearfoot relationship?
(clinically)
A
- put pt in PRONE (lying w/ feet off table)
- find STJNP (palpate talonavicular joint congruency)
- maximally pronate and lock MTJ (apply pressure to submet 4/5)
19
Q
“normal” forefoot to rearfoot relationship?
A
Mets 1-5 are in SAME PLANE, and perpendicular to calcaneal bisector
20
Q
rearfoot varus:
define
A
any condition in the frontal plane that will cause the calcaneus to strike the ground more than 2-3 degrees inward
21
Q
list the conditions that can result in rearfoot varus?
(proximal –> distal)
A
- coxa valga genu varum
- tibial varum
- talar varum
- talar epiphyseal varum
- subtalar varum
22
Q
coxa valga genu varum:
define, and causes
A
- bow-legged, isolated closure of proximal medial epiphysis)
- examples:
- Ricket’s (children, vitamin d deficiency)
- Blount’s (a growth disorder of the tibia (shin bone) that causes the lower leg to angle inward, resembling a bowleg)
23
Q
tibial epiphyseal varum:
define
A
- progressive pathologic genu varum centered at the tibia –> pathologic genu varum in children 2 to 5 years of age
- M>F
- bilat in 50% of cases
- aka infantile blount’s disease
24
Q
what happens at heel strike if foot is inverted too much
A
- Calcaneus MUST EVERT via STJ pronation to bring the medial column of the
foot down to the ground- e.g. if calcaneus is inverted 8 degrees at heel strike, the STJ must
pronate8 degrees tofully compensate - *Only occurs if motion is available –> if not sxs develop
- e.g. if calcaneus is inverted 8 degrees at heel strike, the STJ must
25
when referring to compensation, what joint is moving?
compensation refers to **subtalar joint**
26
how are the types of rearfoot varus defined?
* defined by the **amount of achievable compensation**
* each type has its own characteristic sxs
27
describe the compensation of **rearfoot varus deformities?**
* Rearfoot Varus deformities will **compensate to perpendicular,** but not further
* STJ **pronates**
* MTJ partially UNLOCKS
* Forefoot **ABDucts** on the rearfoot
28
**uncompensated rearfoot varus**:
define
* no available motion at the STJ \<-- so calcaneus can't evert
* calcaneus is forced to function in an INVERTED position throughout the entire stance phase of gait
29
**uncompensated rearfoot varus:**
possible etiologies
* tarsal coalition
* STJ trauma
* muscle spasticity (UMN problem)
* LMN or other disease state
* bowing of calcaneus (intrinsic deformity, structural w/in calcaneus, requires osteotomy)
30
**uncompensated rearfoot varus:**
clinical signs
**"peeking heel sign"** is intrinsic deformity of the calcaneus itself
high arch, tending to be on lateral arch;
**(forefoot has adducted/supinated appearance relative to rearfoot)**
31
which **gene** is associated w/ Charcot-Marie Tooth?
**PMP22 duplications** lead to Charcot-Marie-Tooth disease type 1A (CMT1A)
32
**Charcot-Marie Tooth**:
## Footnote
*type of disorder, sxs, muscle sxs*
* Lower motor neuron disorder (demyelinating polyneuropathy) \<-- **needs neuro workshop**
* sxs:
* **poor muscle definition**
* extreme **cavo-varus**
* extensor substitution **hammertoes**
* inverted **_champagne bottle legs_**
* muscle sxs:
* **peroneal musculature atrophy** although anterior compartment (atrophies 1st)
* unopposed posterior compartment maintains plantarflexion,
* **lesions submet 1/5**
* inc risk of **lateral ankle sprains**
33
what is the characteristic description of Charcot Marie Tooth?
**inverted champagne bottle legs**
34
what occurs if the **rearfoot can't compensate for the varus, but forefoot can?**
* Brings medial forefoot down to ground – TRIPOD EFFECT
* Calcaneus, 1 and 5 are points of contact
* 1st ray axis motion: DF/inv and PF/ev
* 1st Ray PF and everts on its axis through action of Peroneus Longus
35
relationship of metatarsals in **uncompensated rearfoot VARUS,** when the **1st ray is plantarflexed?**
* 1-5 relationship to calcaneus is everted relative to the calcaneal bisector
* 2-5 is perpendicular
36
since the first ray compensates in a case of uncompensated rearfoot varus,
which deformities will NOT occur?
**hallux abductovalgus, hallux limitus/ hallux rigidus** will not occur
* No hypermobility, 1st ray is stable on ground --\> but it may cause excess plantarflexion --\> retracted position of hallux
* However a **cock-up hallux** may develop as a result of the plantarflexion
37
**uncompensated rearfoot varus:**
symptoms (arch and digits)
* High-arched (Cavus) foot type
* Maintained inversion of heel, PF 1st ray
* Poor shock absorption – can present with heel pain syndrome (increased pressure, displacement of medial fat pad)
* Digital contractures
* Intrinsic muscles unable to stabilize proximal phalanx to ground, buckling
* Mechanical advantage to a contracted position (extensor substitution)
38
**uncompensated rearfoot varus:**
symptoms (sesamoids, sprains)
* **Tibial sesamoiditis:** *secondary to PF and everted position of the metatarsal*
* Increased incidence of **bipartite sesamoids**
* to confirm, may get X-ray of contralateral side
* **predisposed to repeated lateral ankle sprains** secondary to fixed supinated position
* injury to ATFL, CFL, PTFL, avulsion fracture, and ankle fracture
39
**uncompensated rearfoot varus:**
symptoms (skin, shoes, joints)
* Callus along **lateral column of foot**
* **hyperkeratotic lesions** on submet 1 and 5
* **Latera**l shoe wear (increases chance of lateral ankle sprain)
* *ask pt if they've noticed a change in the wear pattern of their shoes*
* **Lower back & lateral knee** pain
40
**Iselin's disease:**
define, and type of deformity assoc. w/ it
* painful inflammation of the **apophysis (growth plate) at the base of the 5th met**
(aka apophysitis of 5th met base in children)
* occurs in **uncompensated rearfoot varus**
41
how can you differentiate **Iselin's disease** from a **fracture** of the 5th met base?
The direction of the fracture line
* **Iselin's disease = longitudinal**
* **fracture =** transverse
42
where is the characteristic lesion pattern for **uncompensated rearfoot varus?**
## Footnote
**why?**
hyperkeratotic lesions on **submet 1 and 5**
* Supination creates **increased lateral pressure**
* **1st ray is plantarflexed** – under tibial sesamoid (everted metatarsal)
* Increased pressure during stance, especially propulsion
Pt can also have pain w/o callus formation
43
treatment for **uncompensated rearfoot varus?**
* palliative = **debride lesions**
* orthotics \<-- **goal is to stabilize high arch, redistribute weight away from met heads**
* forefoot extension
* deep heel cup to shift fat pad back
* **lateral dutchman heel** on shoe to prevent supinatory motion/prevent sprains
* **padding** to offload tibial sesamoid
44
compensation is relative to which joint?
subtalar joint
45
**partially compensated rearfoot varus:**
definition/ motion
* **Some STJ pronation** available
* Calcaneus **everts, but not enough** to fully compensate
* Medial forefoot doesn’t come all the way down to ground
* May have **proximal varum deformity** which leads to an excessively inverted position at contact which the STJ can’t fully compensate for
* Calcaneus still functions in an **inverted** position, lateral heel contact
46
are sprains and lateral shoe wear seen more frequently in UNCOMPENSATED or PARTIALLY COMPENSATED rearfoot varus?
Sprains and lateral shoe wear seen **MORE** frequently in **uncompensated**
47
**partially compensated rearfoot varus:**
clinical symptoms
1. **pump-bump** (NOT A HAGLUNDS) - *irritation on posterolateral calcaneus*
2. **tailor's bunion** - \*\*hallmark of partially compensated RF varus
* bowing and splaying of 5th metatarsal
* heloma molle
3. **1st ray sxs**
* if hypermobile --\> HAV + tailors bunion --\> splay foot type
* if PF of 1st met --\> less severe, less symptomatic, may have callus or bipartite sesamoid
4. lesions under **submet 4/5 and pinch callus** (at submet 1)
* due to lateral foot contact first, then medial shift --\> abductory motion on hallux
48
**pump bump:**
assoc. w/ which deformity?
define
tx
* assoc. w/ **PARTIALLY** compensated rearfoot varus
* def: **Enlarged posterolateral surface of calcaneus** due to **irritation/friction** on posterolateral calcaneus due to eversion
* aka: **Retroachilles** and/or **retrocalcaneal bursa/irritation**
* tx:
* Orthotics (decreases need for compensation)
* NSAIDs (anti-inflammatory)
* Injections – into bursa, avoid tendon (can rupture/break down)
49
**Haglund's deformity:**
assoc. w/; define
* assoc. w/ cavus foot
* def: **bony enlargement on the back of the heel due to** increased calcaneal pitch w/ prominence of posterosuperior calcaneus centrally
50
**Tailor's bunion:**
*assoc. w/, define, tx*
* assoc: **hallmark of partially compensated RF VARUS**
* def: Bowing/splaying of 5th metatarsal
* Eversion/pronatory motion trying to bring medial forefoot down to the ground
* Hypermobility of 5th ray axis
* Prominent 5th met head, adductovarus 5th digit
* \*Heloma molle (*soft corn*) in 4th interspace
* tx:
* 5th metatarsal osteotomy/ ostectomy -- depending on severity
* digital derotational arthroplasty
51
**fully compensated rearfoot varus:**
position and motion
* **Pronation available at STJ is equal to the amount of varus at heel strike**
* **Heel** can function perpendicular to the ground in stance
* Forefoot is fully on the ground and weightbearing
* Rapid contact phase pronators – heel everts to perpendicular
* *when you have heel contact; it gets into perpendicular position*
52
**fully compensated rearfoot varus**:
relationship of FF to RF
* Forefoot ABDUCTS relative to the rearfoot
* maintain an arch despite the hyperpronation
* calcaneus ONLY compensates to perpendicular, so talus CANNOT diverge medially
* medial bowing of achilles
53
**fully compensated rearfoot varus:**
symptoms (achille's and 1st ray)
* **Helbing's sign** -- medial bowing of the achilles
* due to eversion motion and if fully compensating for tibial./genu varum (not STJ varum along)
* **1st Ray Hypermobility**
* **Sagittal** plane issue
* **Unlocking STJ and MTJ via pronation** unlocks the 1st ray as you bear weight
* Ground forces push up on the metatarsal which can cause **jamming at the 1st MPJ,** leading to **HL/HR**
* Will only develop HAV **if forefoot adducted on Rearfoot**
54
**fully compensated rearfoot varus:**
sxs (OTHER than achille's/1st ray)
* *these do NOT develop lateral foot symptoms*
* **pump bump**
* **leg cramps**; and postural changes
* pain **submet 2** (secondary to hypermobile 1st ray)
* **hammertoes** (secondary to fatigue of intrinsics)
* *retracted position of toes --\> **anterior displacement of fat pad --\>** inc. submet pressure (**metatarsalgia**)*
* **lesion** patterns
55
**fully compensated rearfoot varus:**
lesion pattern
* **Submet 2** – hypermobilltiy of 1st ray transfers weight laterally (so pressure is submet 2)
* **Plantar hallux IPJ** – in HL/HR, limited ROM at 1st MPJ, so the IPJ compensates
56
**fully compensated rearfoot varus:**
treatment
* ORTHOTICS
* Neutral position orthotics with medial Rearfoot post
* Supports deformity, **maintains RF in inverted position**, controls frontal plane motion, foot does not have to pronate to reach ground –--\> eliminates need for compensation (preventing sxs)
* SURGERY
* to address symptoms, will still need to control with orthotic post op
