Thigh girth measurements have been widely used to quantify rehabilitation progress following knee surgery, but the correlation between thigh girth and other functional measures has not been investigated. This study intended to investigate whether such a correlation exists.
15 women with bilateral osteoarthrosis of the knee participated in this study. Isokinetic knee extensor strength, thigh girth and body mass were measured immediately before, then at six weeks and six months following cementless total knee arthroplasty.
The involved side showed clear pre-operative isokinetic knee extensor strength deficits, and slight reductions in thigh girth. Post-operatively, mean strength deficits were reduced, whereas differences in mean thigh girth became lager. Although thigh girth changes correlated well with body mass, they did not correlate with knee extensor strength.
Changes in thigh girth are mainly due to changes in body mass. Thigh girth measurement is of no use for the quantification of the rehabilitation progress in total knee arthroplasty.