title: Regional migratory osteoporosis: a case report.
abstract: We describe a case of regional migratory osteoporosis (RMO) with clinical images clearly illustrating the migratory behavior of this unusual disorder. RMO is a relatively rare disorder that manifests as rapidly developing, self-limiting, reversible osteoporosis typically seen in the lower limbs of middle-aged men. In our case, the lesion was observed migrating not only from the knee to the ankle within the same limb but also within two compartments of the same knee. To our knowledge, this is the first case showing migration of a lesion both within the same joint and to the adjacent joint. We also present computed tomography images showing characteristic spotty bone defects that are rarely described in the literature, along with magnetic resonance imaging scans revealing bone marrow edema in the affected region. Although little is understood about the etiology or treatment of RMO, knowledge of this disorder is mandatory to avoid its misdiagnosis as some other, more aggressive disease, leading to unnecessary treatment.
authors.affiliation: Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Horiuchi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shiraga
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Fujita
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamagishi
authors.forename: Hiroo
authors.initials: H
authors.lastname: Yabe
mesh_terms: D001284:Atrophy; D001862:Bone Resorption / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D018450:Disease Progression; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography; D013639:Tarsal Bones / Q000473:pathology