Postural stability in patients with osteoarthritis of the hip. Pilot study.

BACKGROUND Total hip arthroplasty involves division of the joint capsule, which can cause receptor damage, affecting postural stability and increasing the risk of falls. The aim of this study was to determine whether postural stability can be disturbed by total hip arthroplasty from a postero-lateral approach. MATERIAL AND METHODS Static balance was quantified with the use of a two plate tensometric platform in a study group of 16 patients (8 women and 8 men) with unilateral hip osteoarthritis, mean age 57.13 (± 10.7) years, height of 173.38 (± 9) cm, weight 90.21 (± 16.9) and BMI of 30.07 (± 2.87) kg/m2. RESULTS Postural balance improved after surgery, with a statistically significant decrease in the length of the sway path in the AP plane and a strong trend towards significance in the medio- lateral plane. The maximum deflection of the COP from the 0 in the Y direction was reduced. The average velocity of movement of the COP along the Y-axis was significantly reduced, and velocity along the X-axis in mm/s was reduced with a strong trend towards significance. CONCLUSIONS 1. THA from a postero-lateral approach did not lead to a deterioration of postural stability in the early postoperative period. 2. Balance parameters, including path length and the average velocity of the COP in the antero-posterior plane, improved in a statistically significant manner. 3. The maximum extension of the COP in the frontal plane decreased with a strong trend towards significance.