Myositis ossificans

Clinic

• MO is essentially metaplasia of the intramuscular connective tissue resulting in extraosseous bone formation (without inflammation).
• It is the most common form of heterotopic ossification (HO), usually within large muscles.

• Some doctors view MO and HO as two points on the same line. They are similar problems that cause pain, local signs of inflammation, and loss of motion.
• In both cases, bone forms in and around soft tissue (usually muscle).
• It occurs after trauma to the muscle or a broken bone. New bone cells form between the torn muscle fibers. This happens most often around the elbow or thigh
• Typically presents as a painful, tender, enlarging mass, which in 80% of cases is located in large muscles of the extremities,

• In the case of paraplegics, recognized episodes of trauma are often absent, and the disease occurs particularly around the knees and hips.

Related disease

• Myopathy / Myositis