Download 19 - University of Virginia School of Medicine

MSK Case Presentation
David Stone
May 22, 2008
19 yo Lacrosse Player
~2 weeks ago, he was hit in his
quadricep with a lacrosse stick.
– Initial injury has improved some, but
are has remained tender.
– He returned to the field after 5 days.
Presents with pain, tenderness,
warmth, focal swelling of his thigh.
New Development: He can palpate a
new “lump” in the leg.
Myositis Ossificans
Heterotopic bone formation in
muscle in the setting of trauma.
Injury: Compression of muscle
tissue against underlying bone with
injury to the muscle, blood vessels,
and periostium.
Seen radiographically about 2-4
weeks after initial hematoma.
Myositis Ossificans
Bone will begin to grow 2-4 weeks
after the injury and mature bone will
be seen by 3-6 months.
Most common in athletic adults in the
2nd or 3rd decade
Usually in the setting of trauma.
Most common locations: Quadriceps,
Brachialis, Deltoid.
Myositis Ossificans
Why do some develop this lesion?
– Not applying ice and compression
immediately after the injury.
– Intensive physiotherapy, massage, or
heat too soon after the injury.
– Returning to play too soon after injury.
Major Differential
Diagnosis
Osteosarcoma
– Sunburst Appearance
Radiological Comparison
Myositis ossificans
– Calcification begins at the periphery and
progresses toward the center.
– Radiographic stabilization or
improvement at 3 to 4 months
Osteosarcoma
– Calcification begins at the center and
progresses to the periphery.
– Continued radiographic growth
Clinical Comparison
Myositis Ossificans is favored with:
– History of trauma to the affected site
– Clinical improvement at 3 to 4 months
Most Important: Pain lessens with time
Pain with osteosarcoma is progressive and
unrelenting.
Myositis Ossificans
Treatment: Conservative
– Rest, Immobilization, Ice
Things that decrease initial hematoma
Will usually resolve on its own
– Surgery: Rarely indicated
Only if it interferes with joint movement or
it irritates a nerve.
Usually wait 12 months for lesion to mature
as shown by bone scan.
If removed before mature, it will likely recur
References
Essentials of Physical Medicine and
Rehabilitation, 1st edition
DeLee and Drez’s Orthopedic Sports
Medicine, 2nd edition
www.bonetumor.org