title: Joint pain undergoes a transition in accordance with signal changes of bones detected by MRI in hip osteoarthritis.
abstract: OBJECTIVE
  In this study, we aimed to investigate whether joint pain is derived from cartilage or bone alterations.
  
  
  METHODS
  We reviewed 23 hip joints of 21 patients with primary hip osteoarthritis (OA), which were classified into Kellgren-Laurence (KL) grading I to IV. Plain radiographs and magnetic resonance imaging (MRI) were obtained from all of the 23 joints. Two of the 21 patients had bilateral hip OA. Pain was assessed based on the pain scale of Denis. A Welch t test was performed for age, height, weight, body mass index, bone mineral density, and a Mann-Whitney U test was performed for KL grading.
  
  
  RESULTS
  Four of 8 hip joints with pain and OA showed broad signal changes detected by MRI. Fourteen hip joints without pain, but with OA did not show broad signal changes by MRI. Collectively, MRI analyses showed that broad signal changes in OA cases without joint pain or with a slight degree of joint pain were not observed, while broad signal changes were observed in OA cases with deteriorated joint pain.
  
  
  CONCLUSIONS
  Our findings suggest that hip joint pain might be associated with bone signal alterations in the hips of OA patients.
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.forename: Yukio
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Shota
authors.initials: S
authors.lastname: Ikegami
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kato
keywords: Hip OA; MRI; joint pain.; signal changes