Prevalence of hip pathology in patients over age 50 with spinal conditions requiring surgery

BACKGROUND: The objective of this study was to evaluate of prevalence of co-existing spine and hip disease using initial screening kidney–ureter–bladder (KUB) radiograph in patients over 50 who underwent spinal surgery. MATERIALS AND METHODS: The study subjects were 388 patients (male: female=117:271; mean age 62.0 years) who underwent spinal surgery between 2008 and 2010. We retrospectively reviewed the initial KUB radiographs used to diagnose the spine and hip disease. Depending on the extent of acetabular and hip joint visualization in KUB, we divided the subjects into three groups: Acetabulum, hip joint, and femoral neck visualization. The hip visualization rate was also assessed with respect to patient height. χ(2) and logistic regression test were used for statistical analysis. RESULTS: 126 (32.5%) cases had significant hip pathology including hip osteoarthritis (Kellgren/Lawrence grade 3 in 123 cases, grade 4 in 3 cases) and avascular necrosis (1 case each of Ficat stage IIA and IIB), and 8 cases had other morphologic abnormalities. Regarding acetabulum–hip visualization in KUB, 7 (1.8%) cases had acetabulum visualization only, 16 (4.1%) had hip joint visualization, and 365 (94.1%) had femoral neck including lesser trochanter visualization. Patients were categorized into four groups according to height (less than 150 cm, 150–159 cm, 160–169 cm, greater than 170 cm). The hip visualization rates differed significantly among these four groups (P<0.05). CONCLUSIONS: The prevalence of discernible hip pathology in patients who underwent spinal surgery was 32.5%. Hip joint visualization was excellent (98.2%) in KUB radiographs. Hence, spinal surgeons should pay attention to hip pathology in surgically indicated spinal patients.