Myositis Ossificans

Myositis ossificans occurs when an untreated area of bruised muscle begins to turn into bone. The condition is relatively common in the arm or thigh. It occurs in 10% to 20% of thigh bruises (contusions). A bruise is caused by bleeding into the soft tissues. If the blood forms a clot (hematoma), it may go through a process called calcification. This turns the clot into bone.


  • Pain, tenderness, swelling, and warmth in the injured limb.

  • Feeling of fullness, deep in the injured limb.

  • "Black and blue" bruising of the skin.

  • Decreased activity (stiffness of the joints) of the injured limb. This includes loss of knee or elbow motion, depending on the area injured.


It is unknown why certain bruises turn into bone. However, most cases result from a direct hit (trauma) that causes a severe bruise.


  • Contact sports, with or without pads (football, hockey, soccer, lacrosse, field hockey).

  • Inadequate protection of exposed areas during contact sports.

  • Bleeding disorders (hemophilia).

  • Blood thinning medicines (warfarin or aspirin).

  • Non-steroidal anti-inflammatory medicines (aspirin and ibuprofen) taken before the injury.

  • Poor nutrition, including lack of vitamins.


  • Wear properly fitted and padded protective equipment (arm or thigh pads).

  • If possible, limit the use of medicines that affect bleeding, before participating in contact sports.


After 3 to 6 months, the affected area typically stabilizes and becomes mature bone. At this point, most athletes feel comfortable returning to sports. However, if pain and disability persist, surgery may be needed to remove the affected section of muscle.


  • Longer healing time, if not properly treated or if not given enough time to heal.

  • Recurring symptoms, if activity is resumed too soon, with overuse, with a direct blow, or when using poor exercise technique.

  • Persistent loss of motion of the affected joint.

  • Weakness of the affected limb.


Treatment first involves ice and medicine, to reduce pain and inflammation. A compression bandage may be worn to decrease swelling. It is important to perform strengthening and stretching exercises. This helps maintain muscle and prevent the muscle from turning into bone. Exercises may be done at home or with a therapist. Rarely, your caregiver will advise drawing out the fluids from the bruise through a needle (aspiration). Surgery is only considered if symptoms cause persistent pain and impairment. Surgery can only be performed once the affected area has become mature bone (6 to 12 months).


  • If pain medicine is needed, nonsteroidal anti-inflammatory medicines (aspirin and ibuprofen), or other minor pain relievers (acetaminophen), are often advised.

  • Do not take pain medicine for 7 days before surgery.

  • Prescription pain relievers are usually prescribed only after surgery. Use only as directed and only as much as you need.

  • Ointments applied to the skin may be helpful.


  • Cold treatment (icing) should be applied for 10 to 15 minutes every 2 to 3 hours for inflammation and pain, and immediately after activity that aggravates your symptoms. Use ice packs or an ice massage.

  • Heat treatment may be used before performing stretching and strengthening activities prescribed by your caregiver, physical therapist, or athletic trainer. Use a heat pack or a warm water soak.


  • Symptoms get worse or do not improve in 6 weeks, despite treatment.

  • New, unexplained symptoms develop. (Drugs used in treatment may produce side effects.).