FIBRODYSPLASIA OSSIFICANS

PROGRESSIVA

A Brief Overview of this

Rare Disease and the

Role of the Podiatrist in

its Management

Contents• Key Facts & Snapshot

• Overview

– Epidemiology

– Prognosis

• Physical Presentation

• Causes

• Diagnosis

• Treatment

• Podiatric Management

• Final Thoughts

KEY FACTS & SNAPSHOT

“Fibrodysplasia ossificans progressiva (FOP) is a rare,

severely disabling, autosomal dominant disease

characterized by recurrent painful episodes of soft tissue

swelling and the development of tumors in subcutis and

muscle tissue. These lesions lead to heterotopic

ossification, that is, true bone tissue formation in the

axial musculature, the ligaments, the fascia, the

aponeurosis, the tendons, and the joint capsules. A

variety of congenital skeletal malformations of the

hands and the feet, especially a hallux valgus deformity

with microdactyly, also are characteristic.” R.A.Schwartz

OVERVIEW

EPIDEMIOLOGY

• FREQUENCY

The prevalence of Fibrodysplasia Ossificans Progressiva (FOP) has been estimated at 1 case per 1.36 to 1.64 million persons in Europe . Fewer than 200 cases have been documented worldwide.

• RACE

FOP mainly occurs in Caucasians but has been reported in those of African decent as well.

• SEX

FOP is more common in females than males. The male-to-male transition of the disease excluded X-linked inheritance. Since few who are affected chose to have children, most patients are considered to have new mutations.

• AGE

FOP usually starts in early infancy; however reports exist of in utero involvement and skeletal deformities are present at birth.*

OVERVIEW

Prognosis

The Prognosis for FOP is poor because of

the involvement of thoracic muscles and

restrictive lung disease. Most FOP patients

are bedridden by the time they are in their

30’s and they usually succumb before their

5th decade.

PHYSICAL PRESENTATION

In most cases, FOP starts in early infancy with

episodes of soft tissue swelling. There have been reports of in utero involvement. Recurrent

periorbital and diffuse soft tissue scalp swelling are

some of the first signs and symptoms. Between the ages of 2-6, ectopic bone formation becomes

evident, then, ectopic bone formation occurs in the ligaments, fascia, aponeuroses, tendons and joint

capsules. Typically this occurs in a proximal-to-distal tendency. Inflammatory flare-ups are common and

often spontaneous but are also frequently associated

with trauma and injury.Most Individuals become bedridden in their 30’s as

motion becomes more and more restrictive.Neuropathic pain (favours females), chronic

neurological symptoms and sensory abnormalities

including deafness, are common.

This Photo by Unknown Author is licensed under CC BY-NC-ND

PhysicalPresentation

• Progressive ankylosis of joints (jaw costals, spine, limbs and digits)

• Bone tumor formation spontaneously and associated with trauma

• Restricted mandibular movement

• Can be associated with alopecia and deafness

• Widespread tumors in the scapular area

• Proximal tibial osteochondromas are a common phenotype

Causes

• Pathophysiology of FOP is unknown

• It is an inherited autosomal dominant disorder with

variable gene expressivity

• Current findings suggest it is involved with at least 1 gene

in the bone morphic protein (BMP) pathway

• The genetic cause of FOP lies within an ACVR1 gene

mutation. The ACVR1 gene encodes a type 1 BMP

transmembrane receptor

• It is believed that these mutations may activate

osteogenic BMP signaling is extraskeletal sites leading to

delayed and progressive ectopic bone formation.

DIAGNOSIS• Based on the presentation of key physical

characteristics

• the presence of bilateral congenital hallux

valgus deformity is highly suggestive of

FOP

• Increased alkaline phosphatase levels for

children

• X-ray findings in abnormal formation of

the great toe, abnormally shaped long

bones with exostoses, and developmental

fusion of the cervical spine

• CT is best for early diagnosis and may

demonstrate herotropic ossification of the

pterygoid muscles

Treatment

• Early diagnosis is of paramount importance (neonatal

period

• Early treatment helps avoid aggravation of the disease,

slow the progress and provide an improved quality of life.

• Systemic steroids sometimes used to for acute

inflammatory flare-ups

• Gene therapy may hold promise in FOP treatment future

• THERE IS NO CURRENTLY KNOW EFFECTIVE MEDICAL

THERAPY FOR FOP

Treatment

The International Clinical Counsel (ICC) on FOP suggests

1. Deep tissue trauma must be avoided

2. Venipuncture, subcutaneous and intravenous meds are OK, but IM injections must be avoided whenever possible

3. Significant precautions should be taken with intubation procedures (general anesthesiology) since the jaw and neck may be partially or completely locked

4. The ICC has produced a 111-page document on the guidelines for FOP medical management

( That document states nothing specific as to the podiatric management of the individual with FOP)

PODIATRIC MANAGEMENT

Fibrodysplasia Ossificans Progressiva

Preserve Mobility/Preserve Productivity

• Handicap parking permit

• Access to clinic, appropriate treatment room space,

furniture and layout

• Orthopedic footwear with palliative accommodations

to promote stable and safe gait indoors and outdoors

• Open access to footwear (full open tongue, open back)

Prevent Injury

• Proper fit footwear

• Non-slip outsole

• Accommodative Orthotic with appropriate materials/top

covers (Plastizote)

• Digital devices as required (tube foam, silicone etc.)

• Avoid injections whenever possible, especially IM

• Avoid surgical options whenever possible elective and

non-critical procedures.

PROMOTE COMFORT

• Conservative lesion debridement

• Conservative nail care

• Accommodative foot orthoses

• Accommodative footwear with pt.

mobility in mind

FINAL THOUGHTS

Questions or Comments?