title: A case with atypical clinical course diagnosed as osteoarthritis, osteonecrosis, subchondral insufficiency fracture, or rapidly destructive coxopathy.
abstract: Osteonecrosis (ON), subchondral insufficiency fracture (SIF), and rapidly destructive coxopathy (RDC) are considered to be clinically different disorders despite exhibiting several overlapping features. We encountered an elderly female patient with an atypical clinical course who was radiographically diagnosed as having osteoarthritis (OA), ON, SIF, and/or RDC over a long-term follow-up. In this case, radiographic diagnosis was apparently affected by the timing of imaging evaluation and was challenging because of radiographic overlap and atypical disease progression. The disorders of OA, SIF, ON, and RDC might share a similar pathophysiology.
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Center of Osteoporosis and Spinal Disorders: Kamimura Orthopaedic Clinic, Matsumoto 399-0021, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Kamimura
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Keijiro
authors.initials: K
authors.lastname: Mukaiyama
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Ikegami
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Uchiyama
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kato
keywords: OA; ON; RDC; SIF.