Hip OA outcomes do not significantly improve with add-on aerobic exercises

In the management of hip osteoarthritis (OA), adding aerobic exercises to resistance training does not appear to substantially produce improvements in hip pain severity and function when compared with resistance exercises alone, according to the results of the PHOENIX study.

PHOENIX included 196 participants (68 percent women) with a clinical diagnosis of symptomatic hip OA. These participants were randomly assigned to undergo a physical activity regimen composed of aerobic and resistance exercises (n=97) or resistance exercises only (n=99). Both groups participated in a home exercise programme and nine consultations with a physiotherapist over 3 months.

The coprimary outcomes were change in hip pain severity (numerical rating scale [NRS] 0–10, with higher scores indicating worse outcomes) and function (Western Ontario and McMaster Osteoarthritis Index [WOMAC]; scale 0–68, with higher scores indicating worse outcomes) at 3 months. Analyses were performed in the intention-to-treat population.

Hip pain improved from baseline to 3 months in both participants who underwent aerobic plus resistance exercises and those who underwent resistance exercises only (2.4 vs 2.2), but the difference was not statistically significant (mean difference, 0.3, 95 percent confidence interval [CI], –0.3 to 0.8; p=0.36).

Likewise, hip function improved at 3 months in both the aerobic plus resistance exercise group and the resistance exercise group only (7.0 vs 8.9), with the difference not reaching significance (mean difference, –0.9, 95 percent CI, –3.6 to 1.8; p=0.51).

As for safety, 24 related adverse events were documented among participants who underwent aerobic plus resistance exercises and 31 among those who underwent resistance exercises only. None of the reported adverse events were serious.