High Prevalence of Symptomatic Knee Osteoarthritis Among Patients Who Have Fragility Hip Fractures

Background: Knee osteoarthritis (OA) is a common degenerative musculoskeletal condition that impairs mobility and balance, increasing fall risk. When combined with osteoporosis, it further increases the risk of fragility fractures. Despite its prevalence, the frequency of knee OA in patients who have fragility hip fractures (FHFs) is not well established. This study aimed to determine the prevalence of knee OA among FHF patients. Methods: We conducted a cross-sectional analysis of patients who underwent surgical treatment for FHF. The knee OA diagnoses followed the American College of Rheumatology criteria, and severity was assessed via the Kellgren–Lawrence classification system. Bone mineral density (BMD) was evaluated at the lumbar spine and contralateral hip, and fall risk was assessed using a self-report questionnaire. Results: Among the 162 patients who had FHF (mean age 79 ± 8.1 years; 80.2% women), 66% had symptomatic knee osteoarthritis (SKOA). Of these, 21.0% were classified as end-stage knee osteoarthritis. Notably, 47.1% of these end-stage knee osteoarthritides were recommended for knee OA surgery before their hip fracture. The presence of SKOA was significantly associated with a history of multiple falls (P = 0.013) and a high fall risk (P = 0.020). Among the 120 patients who had BMD data, 68% had low BMD (T-score ≤ −2.5) at the contralateral hip or lumbar spine. Almost half (45%) of the FHF patients had concurrent SKOA and low BMD, whereas approximately 20% had SKOA, low BMD, and a high fall risk. Conclusions: There is a high prevalence of SKOA among FHF patients. Comprehensive evaluation and management of knee OA and osteoporosis are essential to reduce the risk of subsequent fractures in this vulnerable population.