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SGIM-Myositis Powered By Docstoc
					                                                                                                            MYOSITIS OSSIFICANS
LOGO                                                                        1UCLA, Los Angeles, CA.

  OBJECTIVE                                                                                                                                                         DISCUSSION

                                                                                                                                                                   Myositis ossificans refers to benign, extraskeletal bone
  Diagnose and treat Myositis Ossificans.                                                                                                                          formation within soft tissue, usually muscle. It most often
                                                                                                                                                                   occurs in males in the second and third decades of life. In
                                                                                                                                                                   70% of cases, a history of trauma can be elicited, often
                                                                                                                         X-RAY: Calcifications within the          related to sports injuries. This history may be difficult to
 CASE PRESNTATION                                                                                                        soft tissue of the anterir mid-left       obtain, as with our patient, who did not recall trauma
                                                                                                                         thigh.                                    perhaps secondary to frequent alcohol intoxication.
                                                                                                                                                                   Eighty percent of cases involve the quadriceps or
                                                                                                                                                                   brachialis muscles. Myositis ossificans occurs in 10% of
 A 29-year-old male with a history of alcohol abuse presented to                                                                                                   all quadriceps contusions. Trauma to the muscle triggers
 the emergency department with a three-week history of                                                                                                             proliferative repair with activation of the perimysial
 progressive inability to walk due to left anterior thigh pain and                                                                                                 tissue-inducible osteoprogenitor cells. Risk factors for
 swelling. The patient has a long history of alcohol use with                                                                                                      developing myositis ossificans include a severe or
 episodes of impaired memory. He denied trauma, recent                                                                                                             repeated area of contusion with delays in treatment, use
 strenuous activity, fevers, weight loss, night sweats, and use of                                                                                                 of non-steroid anti-inflammatory agents, application of
 any medications or illicit drugs. His physical exam was                                                                                                           heat, and presence of a joint effusion. The presentation is
 remarkable for a 10 cm area of swelling, induration, and                                                                                                          frequently similar to that in our patient, with pain,
 erythema of the anterior thigh and he was unable to to bear                                                                                                       swelling, and decreased range of motion of the involved
 weight on this leg secondary to pain. Left thigh x-rays performed                                                                                                 muscle group. Induration and enlargement of the mass
 two weeks prior to admission were negative. However, his                                                                                                          occurs with time. The diagnosis is confirmed by the
 admission left lower extremity plain film revealed a 5 cm,                                                                                                        characteristic radiologic finding of “zoning,” which
 calcified, well-circumscribed mass. CT scan demonstrated a 5                                                                                                      describes a distinct peripheral margin of mature
 cm, round mass with a calcified periphery consistent with                                                                                                         ossification and a radiolucent center of immature osteoid
 heterotopic bone. He was admitted for pain control with                                                                                                           and primitive mesenchymal tissue. These findings help to
 narcotics. Physical therapy was initiated and he was discharged                                                       CT SCAN: benign appearing longitudinal      distinguish this benign disorder from osteosarcoma in
 to an acute rehabilitation facility.                                                                                  soft tissue                                 which the central bone is mature. Radiologic
                                                                                                                           calcification in the course of vastus   abnormalities may not be apparent for two to four weeks
                                                                                                                       intermedius muscle                          after the onset of symptoms. Treatment includes pain
                                                                                                                           measuring 14.7 CM length confluent      control and physical therapy with weight bearing as
                                                                                                                       with periostium in the mid                  tolerated and passive range of motion exercises once the
                                                                                                                           femoral shaft                           patient is pain free at rest. Complete resolution of
                                                                                                                                                                   symptoms may require up to two years. Surgical excision
          REFERENCES                                                                                                                                               may be warranted in rare cases, where there is persistent
                                                                                                                                                                   pain, limitation of joint movement, or neurological
           1.   DeLee JC, Drez D. Orthopaedic Sports Medicine 2nd Edition: Principles and Practice.                                                                involvement. However, surgery must be delayed until the
                Philadelphia, WB Saunders, 2003, pp 786-789, 1499-1501.
           2.   Ryan JB, Wheeler JH, Hopkinson WJ, et al: Quadriceps contusions: West Point update. Am J                                                           bone mass matures, which occurs after a minimum of six
                Sports Med 1991;19(3):299-304
           Fu FH, Stone DA (eds): Sports Injuries: Mechanisms, Prevention, Treatment. Baltimore, Williams
                & Wilkins, 1994, pp 758-759

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