International Journal of Physical Medicine & Rehabilitation
Open Access

Abstract

Total Hip Replacement Improves Aerobic Capacity in Osteoarthritis Patients: A Prospective Experimental Study

Unyo C, Caceres E, Salazar J, Gich I and Coll R

Background: Total hip arthroplasty (THA) is the treatment of choice in advanced hip osteoarthritis and has shown its effectiveness in reducing pain and improving the individual’s function and quality of life. The objectives of our study were to measure the effects of hip osteoarthritis and the post-arthroplasty changes on aerobic capacity and gait parameters.

Methods: This was a prospective, experimental study on 37 patients with hip osteoarthritis pending THA. We registered clinical parameters (range of motion, muscular balance, Visual Analogue Scale [VAS] and use of analgesics), functional scales (Lequesne, Johanson) and metabolic parameters (VO₂, VCO₂) in the preoperative period and at 6 months after the intervention. The development of the compromised hip was analysed with the Friedman test, the ergometric parameters were analysed using ANOVA and the correlations between the clinical and ergometric parameters were analysed with a multiple linear regression model.

Results: We analysed 40 THA in 25 men and 12 women, mean age of 63.9 ± 9.6 years. Hip flexion improved 20º, while the abduction and the rotations improved 10º. Muscular balance continued to show differences with the contralateral limb. The VAS value dropped 52%. In the postoperative follow-up, 71% of the patients did not require analgesics. The scores for the functional scales improved between 30% and 45%. Only 3 individuals exceeded the anaerobic threshold in the preoperative control, while 21 did so after the THA. Likewise, the maximum oxygen consumption rose 18% and the energy expenditure of walking decreased by 29%.

Conclusions: All of the clinical and ergometric parameters showed statistically-significant improvements. The parameters that correlated best with decreased energy expenditure for walking were the reduction in pain and in use of analgesics and the increase in capacity and in walking speed.