2Myositis OssificansMyositis ossificans results from a complication of a contusion injury and occurs when part of of the hematoma is replaced with bone. This condition can occur anywhere in the body but more commonly occurs in the quadriceps.The bone deposits may occur as a separate piece or pieces of bone lying entirely within the muscle or attached to the bone (exostosis).
3Myositis OssificansThese calcium deposits are thought to be caused by periosteal cells that invade the hematoma following the injury.This causes a partial avulsion of muscle fibers from the periosteum.
4Mechanism of Injury and Presentation Usually caused by injuries that result in a severe contusion or chronic contusion injuries.Patient will first present with severe pain at first usually with a contusion and a palpable mass within the muscle.
5Signs and SymptomsBruisingPainPalpable mass in muscle
6 Examination and Evaluation HistoryHow did it occur?When did it occur?What type of pain do you have?Does the pain change at different times?Is there any other sensation rather than pain?Is there any swelling? If so, was swelling immediate or did it come later? Observation Look at how the athlete moves.Look for swelling, contusion, and ecchymosis.Check for a palpable mass within the muscle. Mass usually shows up within 2-3 weeks.
7Examination and Evaluation PalpationPalpate along the muscle and around the contused area to feel for a calcium deposit. Special TestManual Muscle Testing- assess the strength of the athlete you are testing.Check Range of Motion-check the athlete’s range of motion to see if calcium deposit is decreasing ROM.
8Referral/Diagnostic Procedure Plain Film RadiographsMRI
9Rehabilitation and Protection Range of Motion ExercisesStretchProtective covering over the injured area.
10Treatment Heat Massage Ultrasound * If the condition is painful and restricts motion, the calcium deposit may be removed after one year with much less likelihood of its return. Too-early removal of the formation may cause it to return.
11Questions What is myositis ossificans? a. contusion b. calcium deposit c. an avulsion fractured. inflammed muscleMyositis ossificans is result ofa. repetitive contusionsb. severe hematomac. untreated contusiond. all the above
12QuestionsMyositis ossificans is caused by ____ cells that invade a hematoma.a. osteoblasticb. osteoclasticc. periosteald. none of the aboveA palpable mass in the muscle will be seen _____.immediatelynever4-6 weeks2-3 weeks
13QuestionsCalcium deposits should only be removed under what condition(s)?a.condition is severely painfulb. motion is restrictedc. mass is too larged. contusion has been resolved
14SourcesArnheim, Daniel D.& Prentice, William E. (1999) Principles of Athletic Training. 10th edition. pg Boston: McGraw Hill PressBosher, James M. & Thibodeau, Gary A.(1994) Athletic Injury Assessment. pg.520Larson,Christopher M. MD; Louis C. Almekinders, MD; Spero G. Karas, MD; William E. Garrett, MD, PhD (February 2002). The Physician and Sportsmedicine. Vol.30 No.2 “Evaluating and Managing Muscle Contusions and Myositis Ossificans .”Prentice, William E.(2003) Therapeutic Modalities for Sports Medicine and Athletic Training. 5th edition. pgRuane, Joseph J., DO; Thomas A. Rossi, MD(April 1997). The Physician and Sportsmedicine. Vol.26 No.4 “When Groin Pain Is More Than 'Just a Strain': Navigating a Broad Differential”