Myositis ossificans

Myositis ossificans
Classification and external resources
ICD-10	M61.
ICD-9	728.1
MeSH	D009221

Myositis ossificans comprises two syndromes characterized by heterotopic ossification (calcification) of muscle.

Classification

• In the first, and by far most common type, nonhereditary myositis ossificans (commonly referred to simply as "myositis ossificans", as in the remainder of this article), calcifications occur at the site of injured muscle, most commonly in the arms or in the quadriceps of the thighs.
  • The term myositis ossificans traumatica is sometimes used when the condition is due to trauma. It is passive stretching than active exercise, is responsible for bone formation.
• The second condition, myositis ossificans progressiva (also referred to as fibrodysplasia ossificans progressiva) is an inherited affliction, autosomal dominant pattern, in which the ossification can occur without injury, and typically grows in a predictable pattern.

Presentation

The condition may sometimes be diagnosed from radiographs obtained for unrelated problems.

Most (i.e. 80%) ossifications arise in the thigh or arm, and are caused by a premature return to activity after an injury. Other sites include intercostal spaces, erector spinae, pectoralis muscles, glutei, and the chest. Hazy densities are sometimes noted approximately one month after injury, while the denser opacities eventually seen may not be apparent until two months have passed.

If the calcification is located in the adductor muscles, it is known as "Prussian's disease".

Treatment

Treatment is initially conservative, as some patients' calcifications will spontaneously be reabsorbed, and others will have minimal symptoms. In occasional cases, surgical debridement of the abnormal tissue is required, although success of such therapy is limited.

References

it:Miosite ossificante