title: Hip Shape as a Predictor of Osteoarthritis Progression in a Prospective Population Cohort.
abstract: Hip morphology plays a significant role in the incidence and progression of hip osteoarthritis (OA). We hypothesized that hip shape would also be associated with other key factors and tested this in a longitudinal community-based cohort combining radiographic, magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and clinical data.
  
  
  
  Baseline DXA images of the left hip of 831 subjects from the Tasmanian Older Adult Cohort were analyzed using an 85-point statistical shape model. Hip pain was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index, and muscle strength was measured using a dynamometer. Hip structural changes were assessed using MRI and radiographic OA using plain radiographs.
  
  
  
  Six shape modes accounted for 68% of shape variation. At baseline, modes 1, 2, 4, and 6 were associated with radiographic hip OA; modes 1, 3, 4, and 6 were correlated with hip cartilage volume; and all except mode 2 were correlated with muscle strength. Higher mode 1 and lower mode 3 and mode 6 scores at baseline predicted hip pain at followup and higher mode 1 and mode 2 scores were associated with hip effusion-synovitis. Higher scores for mode 2 (decreasing acetabular coverage) and lower scores for mode 4 (nonspherical femoral head) at baseline predicted 10-year total hip replacement (THR), while mode 4 alone was correlated with bone marrow lesions (BMLs), effusion-synovitis, and increased cartilage signal.
  
  
  
  Hip shape is associated with radiographic OA, THR, hip pain, effusion-synovitis, BMLs, muscle strength, and hip structural changes. These data suggest that different shape modes reflect multiple facets of hip OA.
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Harbeer G
authors.initials: HG
authors.lastname: Ahedi
authors.affiliation: Aberdeen Centre for Arthritis and Musculoskeletal Health, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Aspden
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Leigh C
authors.initials: LC
authors.lastname: Blizzard
authors.affiliation: Aberdeen Centre for Arthritis and Musculoskeletal Health, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Fiona R
authors.initials: FR
authors.lastname: Saunders
authors.affiliation: Monash University, Melbourne, Victoria, Australia.
authors.forename: Flavia M
authors.initials: FM
authors.lastname: Cicuttini
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Aitken
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Graeme
authors.initials: G
authors.lastname: Jones
authors.affiliation: Aberdeen Centre for Arthritis and Musculoskeletal Health, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Gregory
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D018771:Arthralgia / Q000175:diagnosis / Q000503:physiopathology; D001175:Arthrography; D019644:Arthroplasty, Replacement, Hip; D018450:Disease Progression; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000503:physiopathology; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D010147:Pain Measurement; D066230:Patient-Specific Modeling; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013585:Synovitis / Q000175:diagnosis / Q000503:physiopathology; D013648:Tasmania; D013997:Time Factors