Disease-specific gender differences among total knee arthroplasty candidates.

BACKGROUND

Women with knee osteoarthritis are less likely to undergo joint replacement despite greater self-reported disability. The primary aim of the present study was to assess gender differences in the type and magnitude of osteoarthritis-related impairment prior to knee arthroplasty.

METHODS

Two hundred and twenty-one knee arthroplasty candidates (ninety-five men and 126 women) and forty-four healthy gender, age, and body mass index-matched individuals were tested. Individuals with contralateral limb injury or abnormality, cardiovascular disease, neurological impairment, and medical conditions limiting activity were excluded. Collected data included Medical Outcomes Study Short Form-36 mental and physical component scores, the Knee Outcome Survey Activities of Daily Living Scale score, knee range of motion, timed up-and-go test time, stair-climb test time, six-minute walk distance, normalized quadriceps strength, and volitional muscle activation.

RESULTS

Women in the arthroplasty group had lower Short Form-36 and Knee Outcome Survey scores, longer timed up-and-go test and stair-climb test times, shorter six-minute walk distances, and lower normalized quadriceps strength compared with men. Healthy women had longer stair-climb test times and shorter six-minute walk distances in comparison with healthy men. Between-group comparisons revealed that women in both the control group and the arthroplasty group had reduced normalized quadriceps strength in comparison with men, that healthy women had higher voluntary muscle activation in comparison with healthy men, and that female arthroplasty candidates had lower activation levels in comparison with male candidates.

CONCLUSIONS

Observed gender differences in strength and function appear to be inherent but are magnified in arthroplasty candidates. Strength and functional decline should be closely monitored in women with knee osteoarthritis to serve as an indicator of worsening condition, and preoperative interventions should reflect these gender-specific impairments.