Association Between Radiographic Knee Osteoarthritis, Pre-Fracture Mobility, and Hip Fracture Patterns in Older Adult...

BACKGROUND Hip fracture morphology in older adults is influenced not only by bone mineral density but also by biomechanical and functional factors. Knee osteoarthritis (KOA) can alter lower-limb alignment, load distribution, and gait patterns, potentially affecting the type of hip fracture sustained. This study aimed to evaluate the association between radiographic KOA and hip fracture type while accounting for osteoporosis and pre-fracture mobility. MATERIAL AND METHODS This single-center retrospective cohort study included patients aged ≥65 years admitted with low-energy hip fractures between January 2018 and December 2023. Radiographic KOA was assessed using Kellgren-Lawrence classification, defined as grade ≥2. Osteoporosis was evaluated using dual-energy X-ray absorptiometry within 1 year before fracture. Pre-fracture mobility was assessed using the Parker Mobility Score, categorized as high (7-9), moderate (4-6), or low (0-3). Hip fractures were classified as femoral neck or intertrochanteric. Multivariable logistic regression identified predictors of intertrochanteric fracture. RESULTS Ninety-two patients (mean age 79.1±7.8 years; 67.4% female) were included. Intertrochanteric fractures occurred in 55 patients (59.8%). KOA was present in 56 patients (60.9%), and osteoporosis in 64 (69.6%). Intertrochanteric fractures were more common in patients with KOA (71.4% vs 41.7%, P=0.006). Low mobility was also associated with higher rates (79.4% vs 54.8% vs 40.7%, P=0.007). KOA (OR 2.87; 95% CI, 1.18-6.99; P=0.020) and low mobility (OR 3.41; 95% CI, 1.42-8.19; P=0.006) were independent predictors, whereas osteoporosis was not. CONCLUSIONS KOA and reduced mobility were found to be independently associated with intertrochanteric fracture patterns, underscoring the role of biomechanical and functional factors beyond bone density.