Posterior Tibial Tendon Dysfunction Flashcards
in what type of foot is PTTD most likely to occur in
- an already excessively pronated foot
- the STJ axis is medial deviated causing more surface area available lateral to the STJ axis allowing ground reactive forces to cause a greater pronatory moment
treatment of PTTD
-address the medially deviated STJ axis by increasing the GRF medially to cause a supinatory moment at the STJ
PTTD is aka
adult acquired flat foot
acquired flat foot may occur as a result of
several conditions:
- PTTD
- fractured sustentaculum tali
- calcaneal fractures
- etc.
what ligaments are effected with acquired adult flat foot
- spring ligament
- STJ interosseous lig
what ligaments may be effected with acquired adult flat foot
- anterior portion of the deltoid
- plantar MT ligaments
- plantar naviculocuneiform lig
clinical testing for PTTD
- test for strength and pain of the posterior tibial tendon
- heel raise test
- Hubscher maneuver (Jack test)
- Hinterman test
Stage 1 (Johnson and Strom)
- normal tendon length
- mild degeneration
- medial foot and ankle pain and swelling
- mild weakness
- no deformity
goal/ treatment for stage 1 PTTD
-reduce the rate and amount of pronation from heel strike to midstance (reduce the deceleration function of the TP)
what test should be used to determine what orthosis to precribe
-Hubscher maneuver and the 1st ray raise test (Hinterman) may be used to help decide if biomechanical control is indicated
Classification Systems of PTTD
Johnson and Strom(with Myerson modification)-based on clinical findings
Conti-based on MRI findings
Mueller- based on type/mechanism of tendon injury
for stage 1 PTTD what orthoses can be prescribed
- function devices (cast in neutral position, for patients who have no deformity or changes in strength or flexibility)
- UCBL devices (cast in neural or rectus depending on the flexibility of the flatfoot)
Stage 1 PTTD - orthotic modifications
High medial flange Lateral clip Deep heel seat Medial heel post flare Extended medial heel post Undercut lateral heel post First ray cutout Arch fill (on the device) Wide width Kirby skive Blake inverted pour Heel lift
*SHOULD INCLUDE A DEEP HEEL SEAT AND WIDE WIDTH
what does an extended medial heel post prolong
-the varus force at the RF
a medial heel flare may help
-decrease pronation over the top of the device
problems with a medial heel flare
- limits shoe gear
- not undercutting heel post might be better
purpose of an undercut lateral heel post
- decreases the pronatory lever arm
- may lead to lateral ankle sprain
how can a 1st ray cut out aid with PTTD
- improves the lever arm of the PL
- the resupination force required of the TP may be decreased
stage 1 PTTD shoe modifications
Medial heel flare
Varus heel wedge
Heel lift
Extended heel counter/Heel counter reinforcement
are shoe modifications adequate alone
no, but are best used in conjunction with orthoses or braces
stage 1 PTTD bracing
Ankle stirrup types and over-the counter types of AFOs
Arizona brace
Marzano brace
Richie brace
Double upright hinged brace with an “orthopedic” shoe
describe the Arizona brace
a leather and polypropylene AFO, cast in partial weightbearing on a 1/2 in. contour board
A gauntlet type of ankle brace (wrap around and tie on)
when is an Arizona brace best used to treat PTTD
- stages 1 & 2
- maybe used for stage 3
- 90% sucess rate for stage 1 & 2
what is a Richie Brace
- a functional orthosis incorporated in to an AFO
- cast in neutral position
what is a Marzano Brace
a UCBL incorporated in to an AFO
Stage 2 (Johnson and Strom)
- attenuation of the tendon
- increased pronation (calcaneal eversion/ FF abduction, increased FF supinatus)
- decreased muscle strength of the posterior tibial tendon
goal/treatment for stage 2 PTTD
- return the foot to its more normal position
- prevent residual deformity
Stage 2 PTTD Orthoses
- functional with modifications; cast neutral or rectus
- UCBL; cast rectus
stage 2 PTTD - orthotic modification
-same as stage 1 High medial flange Lateral clip Deep heel seat Medial heel post flare Extended medial heel post Undercut lateral heel post First ray cutout Arch fill (on the device) Wide width Kirby skive Blake inverted pour Heel lift
*SHOULD INCLUDE A DEEP HEEL SEAT AND WIDE WIDTH
Stage 2 PTTD shoe modifications
Medial heel flare
Extended heel counter
Medial stabilizer
Varus wedge
stage 2 PTTD Braces
Richie Brace
Arizona Brace
Marzano Brace
Stage 3 (Johnson and Strom)
The severe pronatory deformity becomes rigid with associated rearfoot arthritis
Fixed everted position of the calcaneus
fixed forefoot supinatus deformity
goal/treatment for stage 3 PTTD
-support the deformity and minimize compensatory changes proximal and distal to the deformity
stage 3 PTTD orthoses
- accommodative device (cast off weight bearing pronated or partial wt bearing; need more rigid material to prevent further collapse)
- Shaffer plate (cast of wt bearing pronated or partial wt bearing)
stage 3 PTTD orthotic modifications
-pocket for plantar prominences (usually for the navicular tuberosity)
stage 3 PTTD shoe modifications
- rocker sole
- medial arch last expansion
- medial stabilizer
how do rocker soles aid PTTD
- heel rocker helps control the rate of loading during the contact phase (decrease lever arm)
- FF rocker eliminates the need for resupination
- should be used with many of the AFOs
how does a medial last expansion aid PTTD
- increases contact medial to the STJ axis
- accommodates the convex medial foot shape associated with PTTD
how does a medial stabilizer (buttress) aid PTTD
-reinforces the medial side of the shoe above the sole to prevent the foot from pronating over the shoe or an orthosis
stage 3 PTTD braces
Richie Brace
Arizona Brace
Marzano Brace
Stave 4 PTTD
in addition to the fixed valgus deformity at the STJ, the ankle functions in a valgus position
treatment/goal for Stage 4
allow for a stable foot/ankle for ambulation
stage 4 PTTD orthoses
- a foot orthosis alone is not indicated
- a foot orthosis incorporated into a more proximal brace may be a possibility
stave 4 PTTD orthotic modification
no applicable
stage 4 PTTD shoe modifications
- custom molded shoes
- medial last expansion
- medial buttress
- rocker sole
stage 4 PTTD braces
Patellar-tendon bearing brace
“Stage 4” Richie Brace
In Conclusion
Aim the treatment at the stage of the deformity
Keep ALL aspects of the footwear in mind and do not hesitate to use a combination of orthoses, orthotic modifications, shoe modifications and/or braces
If the patient is potentially a surgical candidate, be willing to admit when it is time to give up and recommend surgery.
