Table 3.

Longitudinal associations between knee joint effusion synovitis and knee pain. Dependent variables: knee pain (change of 0 vs ≥ 1 for pain); and independent variables: knee joint effusion synovitis (0–3). Values are RR (95% CI).

Effusion Synovitis SubregionsMultivariable*Multivariable**
Suprapatellar pouch
  Total knee pain1.37 (1.15–1.62)1.26 (1.04–1.52)
  Pain when walking on a flat surface1.58 (1.23–2.03)1.44 (1.05–1.96)
  Pain when going up/down stairs1.41 (1.16–1.72)1.27 (1.01–1.59)
  Pain at night while in bed1.29 (1.00–1.66)1.28 (0.97–1.69)
  Pain when sitting or lying1.45 (1.10–1.91)1.47 (1.08–2.00)
  Pain when standing upright1.36 (1.03–1.80)1.22 (0.88–1.69)
Central portion
  Total knee pain1.10 (0.91–1.32)1.14 (0.92–1.41)
  Pain when walking on a flat surface1.09 (0.83–1.43)1.04 (0.74–1.47)
  Pain when going up/down stairs1.09 (0.88–1.35)1.07 (0.83–1.39)
  Pain at night while in bed1.10 (0.84–1.45)1.16 (0.86–1.57)
  Pain when sitting or lying1.26 (0.94–1.68)1.31 (0.96–1.79)
  Pain when standing upright1.18 (0.88–1.58)1.19 (0.85–1.66)
Posterior femoral recess
  Total knee pain1.22 (1.03–1.44)1.37 (1.15–1.63)
  Pain when walking on a flat surface0.94 (0.71–1.25)0.99 (0.72–1.36)
  Pain when going up/down stairs1.01 (0.82–1.25)1.13 (0.90–1.41)
  Pain at night while in bed1.29 (1.00–1.65)1.47 (1.15–1.89)
  Pain when sitting or lying1.33 (1.04–1.70)1.47 (1.14–1.89)
  Pain when standing upright1.10 (0.83–1.46)1.06 (0.77–1.48)
Subpopliteal recess
  Total knee pain1.17 (1.01–1.35)1.13 (0.96–1.32)
  Pain when walking on a flat surface1.27 (1.03–1.56)1.21 (0.94–1.55)
  Pain when going up/down stairs1.10 (0.93–1.30)1.01 (0.84–1.23)
  Pain at night while in bed1.17 (0.96–1.43)1.23 (0.99–1.51)
  Pain when sitting or lying1.19 (0.95–1.49)1.26 (1.00–1.59)
  Pain when standing upright1.21 (0.95–1.53)1.10 (0.84–1.45)

  • ↵* Adjusted for age, sex, and body mass index.

  • ↵** Further adjusted for radiographic osteoarthritis, bone marrow lesions, cartilage defects, and meniscal lesions.

  • Values denoting statistical significance at α = 0.05 are in bold face. RR: relative risk ratio.