Gender and arthroplasty type affect prevalence of moderate-severe pain post total hip arthroplasty

Objective: To investigate the impact of gender, age and arthroplasty type (primary vs. revision) on prevalence of moderate-severe hip pain. Methods: Using an Institutional Total Joint Registry, we identified a cohort of patients who underwent primary of revision THA from 1996-2004 and responded to the follow-up questionnaires. We compared the prevalence of moderate or severe hip pain based on arthroplasty type, gender and by age (<60, 61-70, 71-80 and >80 years). Results based on gender and type of arthroplasty were analyzed by comparing proportions and based on age by using Chi-square tests, considering a p-value<0.05 significant. Results: Moderate-severe pain was less prevalent following primary vs. revision THA at 1-year (5.5% vs. 9.8%, p<0.001), and 2-years post-surgery (7.5% vs. 16.3% vs.; p<0.001). The prevalence of moderate-severe pain at 1-year post-arthroplasty was similar for women and men, both primary THA and revision THA: 6.3% vs. 4.6%, p=0.13; and 11.8% vs. 7.3%, p=0.058, respectively; and in revision THA at 2-years: 17.7% vs. 14.7%, p=0.068. However at 2-years, more women than men had moderate-severe pain in primary THA group: 8.8% vs. 6.6%, p=0.042, respectively. Age had a significant impact on prevalence of moderatesevere pain after 1- and 2-years after primary THA with lower prevalence of pain in 61-70 yr age group compared to other age categories (p=0.01 and p<0.001), but did not have a significant impact on prevalence of moderate- severe pain postrevision THA (p=0.406 and p=0.397, respectively). Conclusions: Moderate-severe pain was more prevalent in women with primary THA at 2-years, but not at 1-year. This might suggest that factors not directly related to surgery such as anatomical and biochemical differences, bone remodeling, differences in recovery of strength and endurance, activity level or comorbidities may play a role in these differences and need further study.