Pediatric Fibrodysplasia Ossificans Progressiva (Myositis Ossificans) Clinical Presentation

  • Author: Robert J Pignolo, MD, PhD; Chief Editor: Lawrence K Jung, MD   more...
 
Updated: Jul 30, 2009
 

History

  • Individuals with fibrodysplasia ossificans progressiva (FOP) appear normal at birth except for characteristic malformations of the great toes, which are present in all classically affected individuals.
  • Episodic, painful soft tissue swellings or exacerbations usually develop in the preteen years.[7]
  • Although some exacerbations spontaneously regress, most transform soft connective tissues (including aponeuroses, fascia, ligaments, tendons, and skeletal muscles) into mature bone.
  • Minor trauma (eg, intramuscular immunizations; mandibular blocks for dental work; muscle fatigue; blunt muscle trauma from bumps, bruises, falls) or influenza-like viral illnesses can trigger painful new flare-ups of fibrodysplasia ossificans progressiva, leading to progressive heterotopic ossification (HO).
  • Most patients with fibrodysplasia ossificans progressiva are confined to a wheelchair by the third decade of life and require lifelong assistance in performing activities of daily living.
  • The severe disability of fibrodysplasia ossificans progressiva results in low reproductive fitness.
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Physical

  • Two clinical features define classic fibrodysplasia ossificans progressiva: malformations of the great toes and progressive heterotopic ossification.
  • Heterotopic bone replaces skeletal muscle and connective tissues.
  • Heterotopic ossification in fibrodysplasia ossificans progressiva progresses in characteristic anatomic and temporal patterns that mimic the patterns of normal embryonic skeletal formation. Heterotopic ossification is typically seen first in the dorsal, axial, cranial, and proximal regions of the body and later in the ventral, appendicular, caudal, and distal regions.
  • Several skeletal muscles, including the diaphragm, tongue, and extraocular muscles, are spared from fibrodysplasia ossificans progressiva. Cardiac muscle and smooth muscle are also spared from heterotopic ossification.
  • Stiffness of the neck is an early finding in most patients and can precede the appearance of heterotopic ossification at that site.
  • Characteristic anomalies of the cervical spine include large posterior elements, tall narrow vertebral bodies, and fusion of the facet joints between C2 and C7.[8] Although the cervical spine often becomes ankylosed early in life, any minimal residual movement may eventually result in painful arthritic symptoms.
  • Other skeletal anomalies commonly associated with fibrodysplasia ossificans progressiva include short malformed thumbs, clinodactyly, short broad femoral necks, and proximal medial tibial osteochondromas.[9]
  • Severe weight loss may result following ankylosis of the jaw.
  • Pneumonia and right-sided heart failure are complications of rigid fixation of the chest wall.
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Contributor Information and Disclosures
Author

Robert J Pignolo, MD, PhD  Assistant Professor of Medicine, Director, Ralston-Penn Clinic for Osteoporosis and Related Bone Disorders, Department of Medicine, Division of Geriatric Medicine, Associate Director, Structure-Function Biomechanical Core, Penn Center for Musculoskeletal Disorders, University of Pennsylvania School of Medicine

Robert J Pignolo, MD, PhD is a member of the following medical societies: American College of Physicians, American Geriatrics Society, American Society for Bone and Mineral Research, Gerontological Society of America, and National Osteoporosis Foundation

Disclosure: Nothing to disclose.

Coauthor(s)

Frederick S Kaplan, MD  Isaac and Rose Nassau Professor of Orthopedic Molecular Medicine, Chief, Division of Orthopedic Molecular Medicine, Director, Center for Research in FOP and Related Disorders, The University of Pennsylvania School of Medicine; Consulting Surgeon, Department of Orthopedic Surgery, Hospital of The University of Pennsylvania

Frederick S Kaplan, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Society for Bone and Mineral Research, American Society for Microbiology, Johns Hopkins Medical and Surgical Association, and Orthopaedic Research Society

Disclosure: Nothing to disclose.

Eileen M Shore, PhD  Research Associate Professor, Departments of Orthopaedic Surgery and Genetics, University of Pennsylvania School of Medicine

Eileen M Shore, PhD is a member of the following medical societies: American Association for the Advancement of Science, American Society for Bone and Mineral Research, American Society of Human Genetics, and Royal Society of Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD  Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

David D Sherry, MD  Director, Clinical Rheumatology, Attending Physician, Pain Management, The Children's Hospital of Philadelphia; Professor of Pediatrics, University of Pennsylvania

David D Sherry, MD is a member of the following medical societies: American College of Rheumatology and American Pain Society

Disclosure: Nothing to disclose.

Daniel Rauch, MD, FAAP  Director, Pediatric Hospitalist Program, Associate Professor, Department of Pediatrics, New York University School of Medicine

Daniel Rauch, MD, FAAP is a member of the following medical societies: Ambulatory Pediatric Association, American Academy of Pediatrics, and Society of Hospital Medicine

Disclosure: Baxter Honoraria Consulting

Chief Editor

Lawrence K Jung, MD  Chief, Division of Pediatric Rheumatology, Children's National Medical Center

Lawrence K Jung, MD is a member of the following medical societies: American Association for the Advancement of Science, American Association of Immunologists, American College of Rheumatology, Clinical Immunology Society, and New York Academy of Sciences

Disclosure: Nothing to disclose.

Acknowledgments

The authors and editors of eMedicine gratefully acknowledge the contributions of previous authors Donald A Person, MD, and Mandar A Pattekar, MD, MS, to the original writing and development of this topic.

References

  1. Cohen RB, Hahn GV, Tabas JA, et al. The natural history of heterotopic ossification in patients who have fibrodysplasia ossificans progressiva. A study of forty-four patients. J Bone Joint Surg Am. Feb 1993;75(2):215-9. [Medline].

  2. Kaplan FS, Glaser DL, Shore EM, et al. The phenotype of fibrodysplasia ossificans progressiva. Clin Rev Bone Miner Metab. 2005;3:183-188.

  3. Kaplan FS, Groppe J, Pignolo RJ, Shore EM. Morphogen receptor genes and metamorphogenes: skeleton keys to metamorphosis. Ann N Y Acad Sci. Nov 2007;1116:113-33. [Medline].

  4. Shore EM, Xu M, Feldman GJ, et al. A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva. Nat Genet. May 2006;38(5):525-7. [Medline].

  5. Kaplan FS, Xu M, Seemann P, Connor JM, Glaser DL, Carroll L, et al. Classic and atypical fibrodysplasia ossificans progressiva (FOP) phenotypes are caused by mutations in the bone morphogenetic protein (BMP) type I receptor ACVR1. Hum Mutat. Mar 2009;30(3):379-90. [Medline].

  6. Kaplan FS, Le Merrer M, Glaser DL, et al. Fibrodysplasia ossificans progressiva. Best Pract Res Clin Rheumatol. Mar 2008;22(1):191-205. [Medline].

  7. Rocke DM, Zasloff M, Peeper J, Cohen RB, Kaplan FS. Age- and joint-specific risk of initial heterotopic ossification in patients who have fibrodysplasia ossificans progressiva. Clin Orthop Relat Res. Apr 1994;243-8. [Medline].

  8. Schaffer AA, Kaplan FS, Tracy MR, et al. Developmental anomalies of the cervical spine in patients with fibrodysplasia ossificans progressiva are distinctly different from those in patients with Klippel-Feil syndrome: clues from the BMP signaling pathway. Spine (Phila Pa 1976). Jun 15 2005;30(12):1379-85. [Medline].

  9. Deirmengian GK, Hebela NM, O'Connell M, Glaser DL, Shore EM, Kaplan FS. Proximal tibial osteochondromas in patients with fibrodysplasia ossificans progressiva. J Bone Joint Surg Am. Feb 2008;90(2):366-74. [Medline].

  10. Adegbite NS, Xu M, Kaplan FS, Shore EM, Pignolo RJ. Diagnostic and mutational spectrum of progressive osseous heteroplasia (POH) and other forms of GNAS-based heterotopic ossification. Am J Med Genet A. Jul 15 2008;146A(14):1788-96. [Medline].

  11. Pignolo RJ, Foley, KL. Non-hereditary heterotopic ossification. Implications for injury, arthropathy, and aging. Clin Rev Bone Miner Metabol. 2005;3:261-266.

  12. [Guideline] Morrison WB, Dalinka MK, Daffner RH, et al. Expert Panel on Musculoskeletal Imaging. Soft tissue masses. [online publication]. Reston (VA): American College of Radiology (ACR);. 2005;6 p.

  13. Kitterman JA, Kantanie S, Rocke DM, Kaplan FS. Iatrogenic harm caused by diagnostic errors in fibrodysplasia ossificans progressiva. Pediatrics. Nov 2005;116(5):e654-61. [Medline].

  14. Kaplan FS, Strear CM, Zasloff MA. Radiographic and scintigraphic features of modeling and remodeling in the heterotopic skeleton of patients who have fibrodysplasia ossificans progressiva. Clin Orthop Relat Res. Jul 1994;238-47. [Medline].

  15. Kaplan FS, Xu M, Glaser DL, et al. Early diagnosis of fibrodysplasia ossificans progressiva. Pediatrics. May 2008;121(5):e1295-300. [Medline].

  16. Pignolo RJ, Suda RK, Kaplan FS. The fibrodysplasia ossificans progressiva lesion. Clin Rev Bone Miner Metabol. 2005;3:195-200.

 
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Extensive heterotopic ossification on the back of a patient with fibrodysplasia ossificans progressiva.
Characteristic malformed great toes and hallux valgus.
Tumorlike swellings on the back representing early fibrodysplasia ossificans progressiva (FOP) flare-ups.
Severe limb swelling seen with an fibrodysplasia ossificans progressiva (FOP) flare-up.
 
 
 
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