myositis ossificans orthopaedic aspects

1. PRESENTED BY: DR. NADEEM SARDAR
1st Year PGT, Dept of Orthpaedics,SMCH

2.  Acquired development of non neoplastic heterotopic ossification
within soft tissues
 Most often in response to localized trauma
 Although the process most commonly develops within skeletal
muscle, the term itself is a misnomer, because nonmuscular tissue
may be involved, and inflammation is rare.
 Adolescents & young adults, predominantly men, are affected
most frequently, although it has been reported in infancy as well

3.  PRECIPITATING FACTORS –
 Single or repetitive trauma (70%)
 Severe thermal injury
 Post-traumatic paraplegia
 Brain injury
 Orthopaedic operations – THR

4. GENETIC & DEVELOPMENTAL FORMS –
 Fibrodysplasia ossificans progressiva
 Progressive osseous heteroplasia
 Pseudomalignant heterotopic ossification
 Albright hereditary osteodystrophy
 Parosteal fasciitis

5.  1. NON HEREDITARY MYOSITIS OSSIFICANS
 2.MYOSITIS OSSIFICANS PROGRESSIVA
(“FIBRODYSPLASIA OSSIFICANS PROGRESSIVE”)

6.  Occur in children(due to periosteum is loosely attached around bones)
and in young active males due to trauma to the muscle and soft
tissues(hematoma in muscles)
 Massage following fracture can aggrevate this condition
 Muscles usually involved are -
 Quadriceps
 Brachialis
 Gluteal muscles
 Deltoid

7.  Also called Fibrodysplasia ossificans progressiva OR STONE
MAN SYNDROME
 Autosomal dominant connective tissue disorder
 Muscle tissue and connective tissue –tendons & lig.gradually
replaced by bone (ossified), extra-skeletal or heterotopic bone
that constrains movement
 No cure
 Usualy die early - malnutrition & recurrent infections

8.  Painful lumps and stiffness in the adjoining joint.
 Lumps decrease in a few weeks, but joint mobility reduction persists
EXACERBATING FACTORS FOR OSSIFICATIONS AT NEW
SITES ARE-
 Minor trauma
 Venipuncture
 Biopsy of lumps
 IM injections,
 Dental treatments
 Ossification progresses from proximal to distal and cranial to caudal.

9. CLINICAL FEATURES-
Digits:
 Short hallux in valgus with synostosis short thumbs
 Clinodactyly
 Fibrous Tissues:
 Swelling in aponeurosis, fasciae, and tendons
 Ossification in muscles and fibrous tissue
 Most prominent in the neck, dorsal trunk and proximal extremities
 The sternocleidomastoid muscle is commonly affected
 Kyphoscoliosis

10. Myositiss Ossificans Progressiva- (left) Dorsal view of
patient (upper) B/L clindodactyly of 5th finger of
hands (below) B/L short hallux valgus of feet

11. Xray showing B/L short hallux valgus

13. HISTOPATHOLOGY-
 Four distinct zones:
 1. Central undifferentiated zone- Mitotically active
 2. Surrounding zone of immature osteoidformation – Less active
 3. Zone with new bone – Osteoblast & fibroustissue with trabecular
organization
 4. Peripheral zone of fibrous tissue
 At least 10 days are required following onset of symptoms for these zones
to become apparent.

15. Myositis Ossificans- Histopathology

16. CLINICAL FEATURES-
 Typically begin approximately 1 to 3 weeks after an injury
 Localized pain and a palpable mass.
 Increased warmth, swelling
 Progressive loss of ROM - Hallmark sign
 Low-grade fever
 Mildly elevated ESR

17. RADIOGRAPHIC FEATURES-
 Early plain radiograph-
 Non calcified mass in the soft tissues
 Within 2 to 4 weeks after the injury –
 Floccular calcifications begin to appear within the mass
 If the cambium layer of the periosteum was involved in the
initial injury, a periosteal reaction of the underlying bone
 Over a 6 to 8 wk period - serial x-rays at 1 to 2 wk intervals
show-
 Peripheral osseous maturation of the lesion
 Central lucent zone and a lucent line separating it from the
underlying cortex , distinguishing from an extraosseous
sarcoma
 After5 to 6 months - mature bone is evident, and the lesion
may show a decrease in overall size

18. MYOSITIS OSSIFICANS- A. Knee B. Elbow

20. FIBRODYSPLASIA OSSIFICANS PROGRESSIVA

21.  CT scan –
 Delineats the zonal maturation and cortical separation when the
diagnosis is unclear
 Other imaging modalities –
 Bone scintigraphy
 Ultrasound
 MRI
 Leukocyte scanning, and angiography, particularly in early lesions or in
difficult cases

22. CT scan shows Egg shell calcification

23.  Parosteal Osteosarcoma
 Soft tissue Sarcoma including malignant fibrous
histiocytoma
 Synovial sarcoma

24.  As the calcifications will typically resolve after a period of time,
non-surgical treatment is encouraged.
 Affected limb should be immobilized with bed rest, ice therapy,
and elevation of the affected limb.
 Range of motion exercise can be introduced as long as the range
of motion is not painful.
 For those who had total hip replacement postoperative single
low-dose radiation with 3 weeks of oral indomethacin regimen
will be preventive.

25. INDICATION OF SURGICAL EXCISION –
 Intolerable pain
 Compression of the neurovascular structures
 Limitation of the range of motion of the joint which
affects the activities of daily living.

26. Thanks