Fibrodysplasia ossificans progressiva. A survey of forty-two cases.

Chin-on-Chest Deformity in Patients with Fibrodysplasia Ossificans Progressiva

“…Surgical resection of heterotopic bone is generally contraindicated. Patients are commonly more disabled after surgery than they are before surgery because of the rapid, often explosive, recurrence of heterotopic ossification in response to the operative trauma 1,2,22 . In a case series in which surgical intervention was used to correct thoracolumbar spinal deformity in patients with fibrodysplasia ossificans progressiva and scoliosis, the outcomes were generally poor because of both progression and recurrence of deformity as well as heterotopic ossification at both the operative site and remote sites 23 .…”

“…ibrodysplasia ossificans progressiva is a rare and disabling autosomal dominant disorder of joint malformations and progressive heterotopic ossification [1][2][3][4] caused by a recurrent missense point mutation in activin receptor IA (ACVR1, also called ALK2), a bone morphogenetic protein (BMP) type-I receptor 2,3,5 . Joints become permanently ankylosed in positions that drastically impair activities of daily living and even life itself 6 .…”

“…Joints become permanently ankylosed in positions that drastically impair activities of daily living and even life itself 6 . Progressive heterotopic ossification usually begins in the first decade of life, typically appearing first in the dorsal, axial, cranial, and proximal regions of the body, and then later in the ventral, appendicular, caudal, and distal regions [1][2][3][4]7 . Lesions are characterized by the rapid appearance of painful, highly vascular fibroproliferative swellings that progress through an endochondral process to form mature ossicles of heterotopic bone 3,8 .…”

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“…Subsequently, the shoulders, elbows, wrists, hips, knees, and jaws are affected. 2,4 There is a proximal-to-distal progression in the muscles of the affected extremities. 2 The facial muscles, tongue, diaphragm, and visceral smooth muscles are usually spared.…”

“…Calcifications of affected areas gradually become heterotrophic, causing ankylosis of all major joints of the axial and appendicular skeleton and severe thoracic deformity. 1,4 By early adulthood, most patients develop severe restriction of mobility due to involvement of the upper limbs. Severe involvement of the lower limbs occur more than a decade later.…”