Relationship between Physical Activity Level and Hip Joint Pain in Adult Women with Chiari Pelvic Osteotomy

[Purpose] The purpose of this study was to establish the criteria for postoperative physical activity levels that do not overload the hip joint. We examined the relationship between physical activity levels and hip joint pain in hip osteoarthritis patients. [Subjects] Subjects were 52 females who had osteoarthritis of the hip joint and underwent Chiari pelvic osteotomy. [Methods] Levels of physical activity were evaluated using an activity recorder to measure number of steps as well as duration of activity according to exercise intensity. By using the Harris Hip Score, patients with 40 or more points were classified as the no-pain group, and those with 30 or less points as the pain group. [Results] The number of steps was significantly greater in the pain group than in the no-pain group 10562 ± 2731 steps/day versus 7411 ± 1746 steps/day. The threshold value for the number of steps based on the receiver operating characteristic (ROC) curve was 8981 steps/day, sensitivity was 0.75, and specificity was 0.79. [Conclusion] On the basis of our results, we suggest that walking more than 9000 steps/day is an excessive level of postoperative physical activity that aggravates hip joint pain.