Impact of Preoperative Muscle Strength on Walking Independence After Total Hip Arthroplasty

Does self-reported physical activity relate to physical function and walking ability in female patients with hip osteoarthritis? A cross-sectional multicenter study

BACKGROUND

The effectiveness of a high level of physical activity in maintaining physical function in patients with hip osteoarthritis has not been adequately examined.

OBJECTIVE

This study aimed to determine whether self-reported physical activity is associated with physical function and walking ability in female patients with hip osteoarthritis.

METHODS

This was a multicenter cross-sectional study. The dependent variables were the lower-limb range of motion and muscle strength, and walking ability. Self-reported physical activity was assessed according to the guidelines of the Japanese Ministry of Health, Labor, and Welfare. Multiple regression models were used to determine whether physical activity was significantly related to the dependent variables after adjusting for confounding factors (age, body mass index, hip pain, comorbidity, and severity of hip osteoarthritis).

RESULTS

A total of 167 participants were included in the study. Physical activity was associated with muscle strength in hip flexion (affected/unaffected, β = 0.18/β = 0.16), abduction (β = 0.19/β = 0.26), knee extension (β = 0.22/β = 0.26), Timed Up-and-Go test (β = -0.16), and 5-m walking time test (β = -0.15).

CONCLUSION

In female patients with hip osteoarthritis, greater physical activity was associated with greater lower extremity muscle strength and walking ability.

Association of affected and non-affected side ability with postoperative outcomes in patients undergoing total hip arthroplasty

BACKGROUND

Although several reports have examined the association between preoperative function and postoperative outcomes in patients undergoing total hip arthroplasty (THA), it is unclear whether the ability of the affected or non-affected side particularly impacts on outcomes. We aimed to investigate the association between affected and non-affected side ability and walking independence.

METHODS

We prospectively enrolled 721 consecutive patients who underwent THA. Preoperatively, quadriceps isometric strength (QIS) and one-leg standing time (OLST) were measured. The endpoints were walking independence within 3, 5, 7, 10, and 14 days postoperatively. The associations between preoperative abilities and outcomes were examined using multivariate Cox hazard model, and the area under the curves (AUCs) for outcomes were compared.

RESULTS

We analysed 540 patients after excluding patients who met the exclusion criteria. Both affected and non-affected QIS predicted walking independence within 3 (p = 0.006 and 0.001, respectively), 5, 7, 10, and 14 (both p < 0.001) days postoperatively. For OLST, only the affected side did not predict walking independence within 3 days postoperatively (p = 0.154 and 0.012, respectively), and both sides did at days 5 (p = 0.019 and <0.001, respectively), 7, 10, and 14 (both p < 0.001). The AUCs of the non-affected side ability for walking independence were significantly greater than those of the affected side on postoperative days 3 (0.66 vs. 0.73; p = 0.021) and 5 (0.67 vs. 0.71; p = 0.040), with no significant difference after day 7.

CONCLUSIONS

Both sides abilities were associated with walking independence after THA, but non-affected side was found to be particularly crucial for early walking independence.