title: Subchondral insufficiency fracture of the femoral head in a patient with alkaptonuria.
abstract: We report a patient with alkaptonuria accompanied by bilateral rapidly destructive arthrosis of the hip. The destruction of the left hip joint with its severe functional impairment necessitated total hip arthroplasty (THA). The outcome was satisfactory. Both magnetic resonance imaging (MRI) and pathologic findings were compatible with a subchondral insufficiency fracture. A year and half later, during a follow-up visit, the patient complained of right coxalgia. Radiography showed that the right femoral head had already disappeared, requiring THA of the right hip. Although there have been a few reports of rapid destructive hip osteoarthritis associated with ochronotic arthropathy, the pathogenesis of the destructive change is not clear. Subchondral insufficiency fracture was diagnosed on MR imaging and pathologically confirmed in our patient with alkaptonuria, suggesting that subchondral insufficiency fracture is one of the causes of ochronotic hip destruction.
authors.affiliation: Department of Orthopaedic Surgery, Kyushu Central Hospital, 3-23-1 Shiobaru, Minami-ku, Fukuoka-city, 815-8588, Japan, thamada@kyushu-ctr-hsp.com.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hamada
authors.forename: Takuaki
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Shida
authors.forename: Akihiko
authors.initials: A
authors.lastname: Inokuchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Arizono
mesh_terms: D000368:Aged; D000474:Alkaptonuria / Q000150:complications* / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000293:injuries* / Q000473:pathology; D015775:Fractures, Stress / Q000175:diagnosis* / Q000209:etiology*; D006620:Hip Fractures / Q000175:diagnosis* / Q000209:etiology*; D006801:Humans; D011859:Radiography