Table 1

Baseline characteristics of the cases and controls in the study population

Cases (N=133)
N (%)
Controls (N=133)
N (%)
p Value
Gender
 Male50 (37.59)50 (37.59)NA
 Female83 (62.41)83 (62.41)
Age (mean+SD)60.44±8.9560.30±8.95NA
BMI (mean+SD)29.01±4.9627.33±4.350.0058
Number of knee bending activities2.36 (1.37)1.95 (1.39)0.0229
Knee pain
 No pain50 (37.59)52 (39.01)0.2264
 Infrequent pain43 (32.33)53 (39.85)
 Frequent pain40 (30.08)28 (21.05)
Previous knee injury27 (20.30)17 (12.78)0.1230
Previous knee surgery5 (3.76)4 (3.01)0.7394
Prevalence of Hoffa-synovitis at baseline50 (37.59)40 (30.08)0.0194
Prevalence of effusion-synovitis at baseline61 (46.21)41 (30.08)0.1436
Contralateral knee Kellgren Lawrence Grade
 063 (47.37)63 (47.37)NA
 111 (8.27)11 (8.27)
 2+59 (44.36)59 (44.36)
  • Group difference tests by GEE method accounting for case–control pairs and correlation of knees in individuals with bilateral OA. Criteria used for matching could not be tested. BMI, body mass index; GEE, general estimated equations; OA, osteoarthritis.