Myositis ossificans: Abnormal bone tissue growth in muscles
Posted: September 15, 2021
[caption id="attachment_16117" align="alignright" width="450"]
A bony mass can form after an injury that limits range of motion, can become painful and limit the healing process.[/caption]
Myositis ossificans may sound like a complicated condition, but this abnormal bone-tissue growth is a somewhat common sports injury. This condition is more likely in active young adults and athletes. Sustained at any level of play or competition, myositis ossificans is the formation of bone tissue inside muscle tissue after a traumatic injury to the area.
Deep-muscle bruising or repeated muscular trauma to the same spot usually is the cause of this injury. Bad muscle strains rarely result in myositis ossificans. After the injury, the body begins to deposit bony tissue instead of muscular tissue at the healing site, eventually causing the formation of a hard lump you can feel. There are some early warning signs as you are recovering from the injury to look for.
"In the first few weeks of recovery, pain with motion or stretch of the muscle starts to worsen and feels stiffer," said Dave Smith, physical therapist with Marshfield Clinic Health System. "Instead of the initial swelling of the entire muscle, you will often times feel a smaller area of pain and stiffness the size of a marble up to the size of a small ball in larger muscles."
Myositis ossificans happens when bony tissue forms by mistake as your body heals
By accidentally replacing muscle cells (fibroblasts), with the cells that help form bone (osteoblasts), the body creates a deposit of immature bone inside the muscle tissue. This gradually occurs about two to three weeks after the initial injury. As the bony mass becomes larger, it may become palpable and painful. The mass can limit range of motion for the affected muscles. This can slow the healing process. There's no sure-fire way to know whether myositis ossificans will occur for you after a muscle injury.Prompt response to the injury can help prevent a mass from forming:
- The first 24 hours after a deep muscle bruise are critical to the long-term management of the injury. If you suffer this type of injury, you may need to remove yourself from the event to receive immediate medical attention.
- Apply ice packs immediately after the injury occurs and during the next several days. Ice helps decrease swelling of muscle tissue and gives the tissue a better chance to heal.
- Light stretching of the injured muscle is highly encouraged. However, stretching shouldn't be painful. Continue activity and stretching so your range of motion doesn't become limited. Myositis ossificans is more likely to develop in a sedentary muscle.



