Table 1

 Characteristics of the study population

Joint replacement (n = 18)No joint replacement (n = 95)p Value
Values are mean (SD).
p Values are for the comparison between subjects who underwent knee replacement and those who did not. Comparisons were made using Student’s t test or the χ2 test, as appropriate.
BMI, body mass index; WOMAC, Western Ontario and McMaster Universities osteoarthritis index.
Age (years)64.1 (9.3)63.1 (10.3)0.83
Sex (per cent female)67%56%0.44
BMI (kg/m2)29.9 (5.8)28.6 (4.9)0.28
Tibial bone area (mm2)3624 (517)3413 (591)0.16
WOMAC (pain, stiffness, function)517.4 (172.9)397.2 (222.5)0.02
    Pain102.8 (35.3)77.1 (41.2)0.02
    Stiffness51.5 (16.7)37.4 (22.5)0.01
    Function374.4 (138)290.0 (170.1)0.05
Kellgren–Lawrence radiographic grade
Baseline tibial cartilage volume (mm3)3526 (685)3705 (932)0.34
Annual loss of tibial cartilage (mm3)274 (208)194 (191)0.10
Per cent tibial cartilage loss7.6 (5.8)5.0 (5.0)0.05