Female gender is protective for outcomes after primary total knee arthroplasty: a risk-adjusted analysis

s / Osteoarthritis and Cartilage 20 (2012) S54–S296 S294 587 FEMALE GENDER IS PROTECTIVE FOR OUTCOMES AFTER PRIMARY TOTAL KNEE ARTHROPLASTY: A RISK-ADJUSTED ANALYSIS J.A. Singh , C. Kwoh , D. Richardson , W. Chen , S. Ibrahim . Univ. of Alabama and Birmingham VA Med. Ctr., Birmingham, AL, USA; Univ. of Pittsburgh and Pittsburgh VA Med. Ctr., Pittsburgh, PA, USA; Univ. of Pennsylvania and Philadelphia VA Med. Ctr., Philadelphia, PA, USA; Univ. of Pennsylvania and Philadelphia VA Med. Ctr., Philadelphia, AL, USA; Univ. of Pennsylvania and Philadelphia VA Med. Ctr., philadelphia, PA, USA Purpose: Osteoarthritis is more prevalent in women than men. Joint replacement is an effective treatment option for end-stage knee OA and its utilization is increasing rapidly. There are, however, limited data on gender differences in surgical outcomes after total joint arthroplasty. We sought to examine gender differences in overall mortality, major complications, revision rates and re-admission rates after primary total knee arthroplasty.. Methods: The sample consisted of all primary knee total joint arthroplasties performed in the State of Pennsylvania during the fiscal year 2002. Primary knee arthroplasty was identified using the International Classification of Diseases, Ninth revision, Clinical Modification (ICD-9CM) code 81.54 in the Pennsylvania Health Care Cost Containment Council (PHC4) Database. We excluded patients with revision knee arthroplasty or with hip joint related procedures during index hospitalization. PHC4 includes demographic data from all patient discharges from 170 non-governmental (i.e. non-Veterans Administration) acute care hospitals in the State of Pennsylvania. We used ICD-9 codes to identify major complications such as venous thromboembolism (VTE), myocardial infarction (MI), prosthetic device malfunction, surgical wound infection and revision knee arthroplasty (ICD-9 codes, 81.55, 0080, 0081, 0082, 0083, and 0084). We examined the associations between gender and allcause mortality, major surgical complications. risk of surgical revision at 1-year and at 5-years after index arthroplasty. We adjusted for age, race or ethnicity, hospital teaching status (teaching or non-teaching), insurance status (none or unknown, Medicaid, Medicare/ government, or private), hospital procedure volume (0-100 and >100), and length of hospital stay and the 3M[[Unsupported Character ]] All Patient Refined-Diagnosis Related Group Risk of Mortality (APR-ROM) score, a validated surgical risk score. Results: In sample consisting of 19,312 primary total knee arthroplasties, there were 47 deaths (0.2%) at 30 days and 232 (1.2%) at one year. Within 30 days of index TKA, 1076 (5.8%) had major complications. Table 1 shows unadjusted rates of major complications. Compared to women, men had higher adjusted odds of one-year mortality (Odds Ratio (OR), 1.50; 95% CI, [1.22-1.86]), wound infections (1.23 [1.01-1.49]) and 30-day readmission (1.44 [0.80-2.57]) after primary TKA. Men also had significantly higher risk of revision arthroplasty of the primary TKA at 1-year (Hazard Ratio(HR), 1.60; 95% CI1⁄4 1.27-2.03) and 5-years (1.21; 95% CI1⁄4 1.08-1.37). There were no statistically significant gender differences in the rates of short-term complications (i.e., venous thromboembolism, Table 1 Unadjusted rates (n (%)) of surgical outcomes of TKA comparing women to men