title: Effects of Exercise on Patellar Cartilage in Women with Mild Knee Osteoarthritis.
abstract: OBJECTIVE
  This study aims to investigate the effects of exercise on patellar cartilage using T2 relaxation time mapping of magnetic resonance imaging in postmenopausal women with mild patellofemoral joint osteoarthritis (OA).
  
  
  METHODS
  Eighty postmenopausal women (mean age, 58 (SD, 4.2) yr) with mild knee OA were randomized to either a supervised progressive impact exercise program three times a week for 12 months (n = 40) or a nonintervention control group (n = 40). Biochemical properties of cartilage were estimated using T2 relaxation time mapping, a parameter sensitive to collagen integrity, collagen orientation, and tissue hydration. Leg muscle strength and power, aerobic capacity, and self-rated assessment with the Knee Injury and Osteoarthritis Outcome Score were also measured.
  
  
  RESULTS
  After intervention, full-thickness patellar cartilage T2 values had medium-size effect (d = 0.59; 95% confidence interval, 0.16 to 0.97; P = 0.018); the change difference was 7% greater in the exercise group compared with the control group. In the deep half of tissue, the significant exercise effect size was medium (d = 0.56; 95% confidence interval, 0.13 to 0.99; P = 0.013); the change difference was 8% greater in the exercise group compared with controls. Furthermore, significant medium-size T2 effects were found in the total lateral segment, lateral deep, and lateral superficial zones in favor of the exercise group. Extension force was 11% greater (d = 0.63, P = 0.006) and maximal aerobic capacity was 4% greater (d = 0.55, P = 0.028) in the exercise group than in controls. No changes in Knee Injury and Osteoarthritis Outcome Score emerged between the groups.
  
  
  CONCLUSIONS
  Progressively implemented high-impact and intensive exercise creates enough stimuli and exerts favorable effects on patellar cartilage quality and physical function in postmenopausal women with mild knee OA.
authors: 1Department of Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND; 2Department of Physical Medicine and Rehabilitation, Central Finland Central Hospital, Jyväskylä, FINLAND; 3Department of Diagnostic Radiology, Oulu University Hospital, Oulu, FINLAND; 4Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, FINLAND; 5Department of Radiology, University of Oulu, Oulu, FINLAND; 6Department of General Practice and Primary Healthcare, University of Helsinki, Helsinki, FINLAND; 7Unit of Primary Healthcare, Kuopio University Hospital, Kuopio, FINLAND; 8Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu, Finland; 9LIKES Research Center, Jyväskylä, FINLAND; and 10Department of Orthopedics and Traumatology, University of Helsinki and Helsinki University Hospital, Helsinki, FINLAND.
authors: Jarmo
authors: J
authors: Koli
authors: Juhani
authors: J
authors: Multanen
authors: Urho M
authors: UM
authors: Kujala
authors: Arja
authors: A
authors: Häkkinen
authors: Miika T
authors: MT
authors: Nieminen
authors: Hannu
authors: H
authors: Kautiainen
authors: Eveliina
authors: E
authors: Lammentausta
authors: Timo
authors: T
authors: Jämsä
authors: Riikka
authors: R
authors: Ahola
authors: Harri
authors: H
authors: Selänne
authors: Ilkka
authors: I
authors: Kiviranta
authors: Ari
authors: A
authors: Heinonen
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000473:pathology / Q000503:physiopathology*; D005081:Exercise Therapy / Q000009:adverse effects; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D057071:Patellofemoral Joint / Q000473:pathology / Q000503:physiopathology*; D010809:Physical Fitness; D017698:Postmenopause; D016896:Treatment Outcome