Skip to main content

Table 2 Descriptive statistics for FJS-12 and WOMAC osteoarthritis index across study time points

From: Minimal important differences for the WOMAC osteoarthritis index and the Forgotten Joint Score-12 in total knee arthroplasty patients

Time pointNFJS-12
Mean (SD)
WOMAC Pain
Mean (SD)
WOMAC Function
Mean (SD)
Reference time point: pre-surgerya16211.7 (11.8)47.2 (19.6)41.7 (17.1)
Follow-up: 2 months3632.9 (27.5)83.9 (14.4)77.0 (17.2)
Follow-up: 3 months3141.2 (26.1)85.6 (15.2)76.5 (15.3)
Follow-up: 4 months3151.8 (24.7)84.2 (16.0)80.6 (14.3)
Follow-up: 5 months2450.7 (27.7)90.4 (10.8)81.8 (14.1)
Follow-up: 12 months4068.6 (27.1)92.3 (10.7)84.2 (14.1)
Reference time point: 12 monthsb3759.3 (31.5)89.2 (15.6)79.4 (19.8)
Follow-up: 15 months1268.8 (24.6)94.6 (8.4)86.8 (9.2)
Follow-up: 18 months1659.0 (25.6)88.8 (15.5)78.2 (19.4)
Follow-up: 24 months2354.0 (31.0)85.4 (19.2)77.4 (19.6)
  1. areference score for the 162 patients completing the transition item (change assessment) between 2 and 12 months after surgery
  2. breference score for the 37 patients completing the transition item (change assessment) between 15 and 24 months after surgery. In 14 patients change was assessed at two different time points (i.e. 37 patients provided 51 assessments)