Introduction:

MOP or FOP is a rare autosomal dominant collagen disorder which is characterised by skeletal deformity & progressive heterotopic osteogenesis.[_{3 4}]

Recently Shore et al reported mapping FOP to chromosome 2q23-24 by linkage analysis[₂]. They have further identified an identical heterozygous mutation (617G R206H) in the glycine-serine (GS) domain of the activin A receptor type I (ACVR1) gene, a bone morphogenic protein (BMP) type I receptor in all affected individuals thus far examined.[₂, ₁, ₃]

It occurs in equal prevalence in all the races & there is no predilection for any gender.[₁, ₂]

Average age of onset is 5yrs , with reported onset ranges from fetus to 25yrs.[₄]

Case Report

15 years old girl presented to us with chief complaints of deformity of both upper limbs for 7 yrs, back for 5 yrs, pelvis for 2 yrs, swelling right thigh, leg & foot for 15 days

Figure 1

Figure 1

7yrs back, she started with swelling spontaneously on right shoulder which gradually progressed distally to arm. Swelling was hard in consistency, which resolved over a period of 1month followed by residual deformity of right elbow. This was followed by similar sequence of events in left shoulder, arm & elbow after 1 yr. when she was 9 yrs old the pathology involve the spine & lead to the residual deformities of spine & followed by pelvis deformity after 10 yrs. Recently she had developed similar swelling of right thigh which gradually increased from proximal to distal thigh. Patient has difficulty in walking associated with deformity of spine & pelvis.

On examination, bony hard cord like structure is palpable in the front of both arms, right side of dorsolumbar region, abdominal region, rt. hip & proximal thigh. There is fixed scoliotic deformity with the primary curvature facing right side at dorsolumbar junction. Associated with it is round kyphotic deformity. Both shoulders are in the attitude of adduction & flexion of about 10-20*. Both elbows are in the flexion of 100*.Right hip is in 40* flexion, 20* internal rotation at hip with rt. knee in 30* flexion. There is no deformity in the left lower limb. There is swelling of right thigh, leg & foot. Overlying skin is normal. Hallux valgus is also present. Jaw & neck movements are restricted & no movements at the shoulder & elbow joints. Distal neurovascular status is ok.

Figure 2

Figure 2

Figure 3

Figure 3

Figure 4

Figure 4

Figure 5

Figure 5

Figure 6

Figure 6

Blood biochemistry: no abnormalities in serum calcium or phosphorous level. Serum proteins, albumin or A:G ratio is within normal limits.

Radiological features:

The roentgenographic findings show radiopaque shadows, due the heterotopic bone formation, in the various regions of the body.

X-ray pelvis AP view shows, deformed pelvis & radiopaque speckling shadows around the head & neck of Rt. femur. There is also cord like radiopaque lesion in the facial plane over the lateral aspect of the Rt. femoral shaft.

Figure 7

Figure 7

Figure 8

Figure 8

Figure 9

Figure 9

X-ray of the dorsolumbar spine shows the right sided scoliotic deformity with alpha angle measured by Cobb's method is 60*, there is also overcrowding of ribs on the concave side of the primary scoliotic curve with similar radiopaque cord like shadows due the heterotopic bone formation.

Figure 10

Figure 10

Similar findings is found on the X-rays of left & Rt. shoulder joints

Figure 11

Figure 11

Figure 12

Figure 12

CT- scan: Since cost is main factor and it would not help the pt in any ways so we did not perform it.

Histopathology:Since it is contraindicated [₃, ₅] in the MOP, so we didn't perform

Treatment:

Discussion

MOP / FOP is the rare autosomal dominant connective tissue disorder [₁, ₂, ₃, ₄]that results in the heterotopic osteogenesis & skeletal deformity with no treatment as yet.

There is little convincing evidence that any form of treatment alters the progress of the disease in myositis ossificans progressiva. Treatments that have been used include a diet reduced in vitamin D and calcium, the avoidance of sunshine, and treatment with corticosteroids. Other treatment strategies include beryllium, vitamins B and E and penicillamine. Drugs that block calcification have also been used, including EDTA (disodium ethylene diamine tetraacetic acid), isotretinoin and etidronate, without proven benefit. There is one report of treatment with ascorbic acid. Surgical resection of the ossified sites is usually unsuccessful, with recurrence at the same site.[₆]

A case report of 34-yr-old woman with neurapraxia because of involvement of the Rt. femoral nerve secondary to myositis ossificans progressiva. This disease has no adequate treatment, though low-dose radiotherapy in combination with other treatment strategies may reduce entrapment pain and increase mobility without significant side-effects.[₈]

Following are the differential diagnosis of myositis ossificans progressiva:

• Osteosarcoma

• Weber-Christian disease

• Klippel-Feil syndrome

• Rheumatoid arthritis

• Dermatomyositis of childhood

• Systemic sclerosis

• Calcinosis interstitialis ossificans

• Albright hereditary osteodystrophy

• Pseudohypoparathyroidism

Search is still on regarding the proper treatment modality of myositis ossificans progressiva to put a break on its progression & to revert the disease process.

At last we only want to convey that the purpose of our reporting this case is to make people wiser about this disease. We commit ourselves to all those working on this disease to bring an end to this crippling disease.

Correspondence to

Dr. Sumit Mahajan. 720-A last more Gandhi Nagar, Jammu, J&K Mob no: 0191-94191-89071 Email: mahajan.sumit20@rediffmail.com