Developmental Dysplasia of the Hip, Age, BMI, Place of Residence and Tobacco Abuse Increase the Odds of Aseptic Loosening in Chinese Patients

PURPOSE The purpose of this hospital-based case-control study was to evaluate the patient-related risk factors for aseptic loosening after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in Chinese patients. METHODS From January 2000 to December 2012, 67 patients undergoing THA and TKA who developed aseptic loosening were detected as case subjects and 336 patients without aseptic loosening, matched by the year of index surgery and type of surgery, were selected as controls. Conditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS The demographic factors and comorbid conditions associated with a risk-adjusted increase in aseptic loosening (in decreasing order of significance) were a rural place of residence (OR = 2.28; 95% CI: 1.21-4.30; p = 0.011), body mass index (BMI) ≥ 28 kg/m(2) (vs. 18.5-28 kg/m(2)) (OR = 2.29; 95% CI: 1.19-4.41; p = 0.013), developmental dysplasia of the hip (DDH) (OR = 2.91; 95% CI: 1.11-7.66; p = 0.030), tobacco abuse (OR = 2.88; 95% CI: 1.05-7.89; p = 0.039), and age <45 years (vs. 45-65 years) (OR = 2.63; 95% CI: 1.01-6.80; p = 0.047). CONCLUSIONS Patients aged <45 years and those with a BMI of ≥ 28 kg/m(2), a preoperative diagnosis of DDH, history of tobacco abuse, or living in rural areas are at increased risk for aseptic loosening after THA and TKA in Chinese population. Additional systematic large-scale studies are needed to verify these results.