Myositis ossificans circumscripta of the knee improved by alendronate.
Myositis ossificans circumscripta (MOC) is a rare benign disorder characterized by heterotopic ossification of soft tissues. We report a case in a 21-year-old male who presented with knee pain after strenuous physical activity. Evidence of inflammation of the knee and a hard swelling in the subquadricipital area were the main physical findings. The initial plain radiographs showed a subpatellar soft tissue mass containing flocculent calcifications. Over the next 2 months, the calcific deposits organized into a calcified mass. Magnetic resonance imaging findings were nonspecific, with a mass within the vastus medialis muscle generating low signal on T1 images and high signal on T2 images, without postgadolinium enhancement. Computed tomography showed several calcific deposits arranged in a ring, strongly suggesting MOC. Histological examination of a biopsy specimen confirmed this diagnosis. Alendronate therapy given for 6 months was followed by marked clinical improvement, obviating the need for surgery.
Ben Hamida
Kaouther Saadallaoui
KS
Internal Medicine Department, Domestic Security Forces Hospital, La Marsa, Tunisia. hend.benammar@rns.tn
Hajri
R
R
Kedadi
H
H
Bouhaouala
H
H
Salah
M Hadj
MH
Mestiri
A
A
Zakraoui
L
L
Doughi
M H
MH
D000328:Adult; D019386:Alendronate / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009221:Myositis Ossificans / Q000175:diagnosis* / Q000188:drug therapy*; D010147:Pain Measurement; D011379:Prognosis; D016059:Range of Motion, Articular / Q000502:physiology; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D019386:Alendronate