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.