Foot and ankle issues in collagen disorders

• Patrick Agnew, DPM, FACFAS, FACFAP, Virginia Beach, VA

• Director, Eastern Virginia Medical School podiatry education

• Past President ACFAPediatrics

• Captain, (SCWO), MSC, USNR-R

Previous research

• Common foot problems identified by survey, Seattle, WA

• Xrays taken at Detroit Children’s Hospital evaluated

• Footmax scans collected, Philadelphia, PA

Some collagen disorders

• Ehlers-Danlos Syndrome

• Marfans Syndrome

• Osteogenesis imperfecta

• Etc….

Special considerations

• Soft tissue handling

• Vascular fragility?

• Bone fragility?

• Over pronation or sagging

• Achilles may still be tight!

Common foot problems

• Hypermobility

• “Flat feet” with or without over pronation

Common foot problems

• Uncommon manifestations

• “Bunions” with joint fluid leak (ganglion cyst/”pseudo tumor”)

Principles of podiatric intervention

• Align and maintain functional anatomy

• Avoid skin injury

• Don’t rely on ligaments

• Select and time invasive intervention carefully

Align and maintain functional anatomy

• Foot orthoses-> controversial • Arthrodesis -> anecdotally mediocre results • Osteotomies -> more reliable, much experience • Arthroresis -> controversial but promising • Ligament replacement -> new devices

Sub talar arthroresis

Subtalar Arthroresis

• History/variations

• goals

• Disadvantages

• Advantages

HISTORY

• Chambers 1946: bone block

• Subotnick 1974 silastic carved plug

• Current: Metal implants, Absorbable implants

HISTORY

• Polymers

• Metals

• absorbable

Goals of STA

• Relief of pain

• Improved joint alignment and function

• Interruption of patho-mechanical progression

• “correction” of “deformity”???

STATE OF THE ART

State of the art

Size matters!

• CT measurements of sinus tarsus

• Preliminary radiographic findings and sizing implications on patients undergoing bioabsorbable sub talar arthroeresis, JFAS, 2007

Metatarsus Adductus

• From: Agnew, P in: McGlamery’s comprehensive textbook of foot and ankle surgery. Lippincott Williams and Wilkins, 3rd and 4th editions

Diagnosis • Infancy

• Toddler hood

• Childhood

• Adults

• From: Agnew, P in: McGlamery’s

comprehensive textbook of foot and ankle surgery. Lippincott Williams and Wilkins, 3rd and 4th editions

Multiplanar deformities From: Agnew, P in: McGlamery’s comprehensive textbook of foot and ankle surgery. Lippincott Williams and Wilkins, 3rd and 4th editions

Prognosis • No reliable method

• Uncompensated: styloid process, HAV?, ankle injuries, lateral knee?, claw toes…

• Compensated: complex over pronation, HAV?, hammertoes

Management

• Observation(?)

• “stretching”(?)

• Casting

• Splinting

• Shoes(?)

• Surgery

External fixation

•Mini rails

•May obviate second surgeries, may result in less bone surgeries

Good solutions for bad ligaments

• Strong: absorbable vs non absorbable

• Minimally invasive (small incisions)

• May obviate some bone surgeries

• May permit weight bearing immediately

Suture and button procedures by permission

Pre operative

Post operative

Minimally invasive techniques in development

Internal brace Replaces commonly injured ligaments with strong suture webbing

Small incision

Doesn’t rely on native collagen for reinforcement

Please pray for our troops

US NAVY SEA BEES