Associated Factors for Lumbar Degenerative Spondylolisthesis in Japanese Patients with Osteoarthritis of the Hip: A Radiographic Study

STUDY DESIGN: Retrospective study. PURPOSE: To determine the presence and frequency of factors for degenerative spondylolisthesis (DS) in patients with hip osteoarthritis (OA). OVERVIEW OF LITERATURE: OA of the hip joint (hip OA) in Japanese patients is associated with a high incidence of degenerative lumbar spondylolisthesis (DS). However the associated factors for DS in patients with hip OA are unclear. METHODS: The study included 518 patients (59 men and 459 women) with a mean age of 63.8 years who underwent total hip arthroplasty for hip OA at our hospital between January 2004 and May 2014. The presence of DS was assessed using preoperative standing lateral radiographs of the hip joint including the lower lumbar spine. To identify the associated factors for DS in patients with hip OA, multiple logistic regression analysis was conducted in which the presence or absence of DS was used as a dependent variable, and age, female sex, body mass index (BMI), sacral slope (SS), Crowe classification, and primary OA (P-OA) not associated with acetabular dysplasia were independent variables. RESULTS: Patients with DS accounted for 114 (22.0%) of 518 cases. In multiple logistic regression analysis to identify associated factors for DS in patients with hip OA, the odds ratio for age was 1.05 (95% confidence interval [CI], 1.02–1.08), female sex was 2.48 (95% CI, 1.11–5.54), BMI was 1.08 (95% CI, 1.02–1.14), SS was 1.07 (95% CI, 1.04–1.09), Crowe classification was 0.60 (95% CI, 0.40–0.91), and P-OA was 1.90 (95% CI, 1.20–3.75). CONCLUSIONS: Age, female sex, BMI, SS, low Crowe classification, and P-OA are independently associated factors for DS in patients with hip OA.