Musculoskeletal clinical case of the month – Myositis Ossificans

Myositis Ossificans (MO)

Myositis Ossificans is a complication that can occur after muscle injury, and is particularly prevalent in the athletic population and young adults. It is characterised by abnormal calcification/bone growth in healing muscle after injury and usually occurs in the larger muscle groups. Sports whose participants are particularly susceptible to developing MO include;

  • contact sports where muscle contusion is common (e.g. rugby)
  • sports that involve high velocity running (e.g. sprinting) where muscle tears are common

Myositis Ossificans is the most common form of Heterophic Ossification, the umbrella diagnosis for a group of conditions where there is formation of extraskeletal bone in soft tissues.

Clinical Presentation

  • 46-year-old man
  • Avid marathon runner
  • Blunt trauma to left anterior thigh from fall on stairs 1 week ago
  • DH – Nil anticoagulants. Nil else.
  • PMH – Nil of note
  • FH – Nil of note
  • Examination left thigh
    • Difficulty walking
    • Large tense swelling
    • No bruising
    • Restricted range of knee flexion to 100 degrees
  • Ultrasound in clinic demonstrated;
    • Vastus Intermedius liquified haematoma
    • No other muscle injury
  • Patient had 60mls blood drained from haematoma on the same day and sent home with compression on thigh

Further injury and investigation

  • Patient unfortunately sustained re-injury to quadriceps whilst walking the dog which resulted in fresh re-bleed and new calcification formation
  • Range of knee flexion reduced further and now unable to flex beyond 80 degrees
  • Repeat ultrasound and MRI show development of myositis ossificans in Vastus Intermedius

Imaging

  • Top left – Preliminary Ultrasound showing haematoma pre-drainage
  • Top right – Repeat Ultrasound after re-injury showing initial calcification deposits
  • Bottom left – MRI after re-injury confirming location of deposits in VI
  • Bottom right – X-ray thigh 2 months later showing mild resultant calcification
  • MO collage-1
mo Musculoskeletal clinical case of the month - Myositis Ossificans

Management post re-injury

Medical;

  • Patient started on Indomethacin 200mg daily immediately, taken for 2 weeks total
  • New haematoma not amenable for repeat drainage as not liquified and increased risk of infection

Rehabilitation

  • First 48 hours post-re-injury
    • Tight compression throughout the length of the thigh
    • Offload on crutches
  • First 2 weeks
    • Partial weight-bearing
    • Quadricep length focused on in initial stages with passive prone knee bends
    • Quadricep muscle activation using isometric squeeze exercises
    • Muscle stimulation via compex
    • Pool based activity and stretches
    • Ongoing daily compression
  • Weeks 2-4
    • Return to normal walking unaided
    • Gym based rehab with concentric and eccentric quadriceps, gluteal and hamstring activation
    • Restoration of injured thigh muscle length (including hamstrings)
  • Weeks 4-6
    • Light jogging and continuation of strength and flexibility work
    • Week 8 return to running

Key learning points – Myositis Ossificans

  • Myositis Ossificans is a common condition in active people who exercise and are more susceptible to soft tissue injury
  • It occurs when soft tissue bruising and haematoma, results in calcific deposits
  • Recurrent muscle injury/bruising/haematoma increases the risk of MO
  • It is more common in larger muscle groups e.g. quadriceps, hamstrings
  • It is a radiology ‘DO NOT TOUCH’ lesion, i.e. should be diagnosed directly from x-ray or MRI
  • This is to avoid unnecessary surgical intervention. Biopsy at early stage may be indistinguishable from Sarcoma.
  • Investigation; X-ray is gold standard for detecting MO
  • Management;
    • No clear consensus on how to treat
    • Reducing soft tissue swelling, bruising, haematoma collection can help prevent formation e.g. compression, drainage of fluid
    • Indomethacin commonly used by sports medicine medical prescribers for a period of 2 weeks to prevent calcification
    • Once calcification is present, babotage and shockwave can help break down deposits and improve function
    • Novel therapies such as acetic acid solution administered via iontophoresis have mixed evidence
    • Surgical intervention may prompt further MO development
  • Rehabilitation;
    • Goal is to regain as much range of movement and strength ASAP.
    • Manual therapy and deep soft tissue around MO needs to be done with caution to prevent further spread
    • Normal functionality of muscle can be achieved despite large MO deposits
Recent posts
Subscribe to the free sports medicine newsletter

The medical world can sometimes be daunting. Our experts discuss the latest medical updates in the sport, health and fitness world, and break it down for you into and an easy to understand, digestible summary. And of course, it’s free.

If you have a particular health care question in mind, please get in touch to let us know and we will do our best to guide you.

The LBSM newsletter, written by our doctors, for our patients.