title: Synovial changes detected by ultrasound in people with knee osteoarthritis - a meta-analysis of observational studies.
abstract: To examine the prevalence of synovial effusion, synovial hypertrophy and positive Doppler signal (DS) detected by ultrasound (US) in people with knee osteoarthritis (OA) and/or knee pain compared to that in the general population.
  
  
  
  A systematic literature search was undertaken in Medline, EMBASE, Allied and Complementary Medicine, PubMed Web of Science, and SCOPUS databases in May 2015. Frequencies of US abnormalities in people with knee OA/pain, in the general population or asymptomatic controls were pooled using the random effects model. Publication bias and heterogeneity between studies were examined.
  
  
  
  Twenty four studies in people with knee pain/OA and five studies of the general population or asymptomatic controls met the inclusion criteria. The pooled prevalence of US effusion, synovial hypertrophy and positive DS in people with knee OA/pain were 51.5% (95% CI 40.2 to 62.8), 41.5% (26.3-57.5) and 32.7% (8.34-63.24), respectively, which were higher than those in the general population or asymptomatic controls (19.9% (95%CI 7.8-35.3%), 14.5% (0-58.81), and 15.8 (3.08-35.36), respectively). People with knee OA (ACR criteria or radiographic OA) had greater prevalence of US abnormalities than people with knee pain (P = 0.037, P = 0.010 and P = 0.009, respectively).
  
  
  
  US detected effusion, synovial hypertrophy and DS are more common in people with knee OA/pain, compared to the general population. These abnormalities relate more to presence of OA structural changes than to pain.
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, UK; Arthritis Research UK Pain Centre, Nottingham, UK.
authors.forename: A
authors.initials: A
authors.lastname: Sarmanova
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, UK; School of Health Sciences, University of Nottingham, UK.
authors.forename: M
authors.initials: M
authors.lastname: Hall
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, UK.
authors.forename: J
authors.initials: J
authors.lastname: Moses
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, UK; Arthritis Research UK Pain Centre, Nottingham, UK.
authors.forename: M
authors.initials: M
authors.lastname: Doherty
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, UK; Arthritis Research UK Pain Centre, Nottingham, UK. Electronic address: weiya.zhang@nottingham.ac.uk.
authors.forename: W
authors.initials: W
authors.lastname: Zhang
mesh_terms: D006801:Humans; D007719:Knee Joint; D020370:Osteoarthritis, Knee; D012720:Severity of Illness Index; D013585:Synovitis; D014463:Ultrasonography
keywords: Meta-analysis; Osteoarthritis; Synovial; Synovitis; Ultrasound