title: Legg-Calvé-Perthes disease produces chronic hip synovitis and elevation of interleukin-6 in the synovial fluid.
abstract: Legg-Calvé-Perthes disease (LCPD) is a childhood hip disorder of ischemic osteonecrosis of the femoral head. Hip joint synovitis is a common feature of LCPD, but the nature and pathophysiology of the synovitis remain unknown. The purpose of this study was to determine the chronicity of the synovitis and the inflammatory cytokines present in the synovial fluid at an active stage of LCPD. Serial MRI was performed on 28 patients. T2-weighted and gadolinium-enhanced MR images were used to assess synovial effusion and synovial enhancement (hyperemia) over time. A multiple-cytokine assay was used to determine the levels of 27 inflammatory cytokines and related factors present in the synovial fluid from 13 patients. MRI analysis showed fold increases of 5.0 ± 3.3 and 3.1 ± 2.1 in the synovial fluid volume in the affected hip compared to the unaffected hip at the initial and the last follow-up MRI, respectively. The mean duration between the initial and the last MRI was 17.7 ± 8.3 months. The volume of enhanced synovium on the contrast MRI was increased 16.5 ± 8.5 fold and 6.3 ± 5.6 fold in the affected hip compared to the unaffected hip at the initial MRI and the last follow-up MRI, respectively. In the synovial fluid of the affected hips, IL-6 protein levels were significantly increased (LCPD: 509 ± 519 pg/mL, non-LCPD: 19 ± 22 pg/mL; p = 0.0005) on the multi-cytokine assay. Interestingly, IL-1β and TNF-α levels were not elevated. In the active stage of LCPD, chronic hip synovitis and significant elevation of IL-6 are produced in the synovial fluid. Further studies are warranted to investigate the role of IL-6 on the pathophysiology of synovitis in LCPD and how it affects bone healing.
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.|Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Kamiya
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.|Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Yamaguchi
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: Naga Suresh
authors.initials: NS
authors.lastname: Adapala
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Chen
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: David
authors.initials: D
authors.lastname: Neal
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: Obrien
authors.initials: O
authors.lastname: Jack
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: Alec
authors.initials: A
authors.lastname: Thoveson
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Gudmundsson
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: Case
authors.initials: C
authors.lastname: Brabham
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.
authors.forename: Olumide
authors.initials: O
authors.lastname: Aruwajoye
authors.affiliation: Department of Orthopedic Surgery, University of Connecticut Health Center, Farmington, CT, USA.
authors.forename: Hicham
authors.initials: H
authors.lastname: Drissi
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.|Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Harry K W
authors.initials: HK
authors.lastname: Kim
mesh_terms: D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D007873:Legg-Calve-Perthes Disease / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D011859:Radiography; D013582:Synovial Fluid / Q000378:metabolism*; D013585:Synovitis / Q000000981:diagnostic imaging / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C508585:IL1B protein, human; C508600:IL6 protein, human; D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha
keywords: AVN; FEMORAL HEAD OSTEONECROSIS; HIP SYNOVITIS; IL-6; INTERLEUKIN-6; LCPD; LEGG-CALVE-PERTHES DISEASE; OSTEOIMMUNOLOGY