Risk factors of asymptomatic vertebral compression fractures in patients with ankylosing spondylitis presenting for spine evaluation.

Abstract

Objective: To identify independent clinical and inflammatory risk factors associated with asymptomatic vertebral compression fractures in ankylosing spondylitis patients undergoing routine spinal evaluation. Study Design: Analytical Cross-sectional. Period: January to December 2025. Setting: Department of Neurosurgery, Nishtar Hospital II, Multan. Methods: A total of 289 adults meeting ASAS criteria who underwent spinal imaging. Patients with acute symptomatic fractures, recent trauma, prior spinal surgery, or metabolic bone disorders were excluded. Asymptomatic vertebral compression fractures were defined radiographically using Genant semiquantitative grading without acute pain or neurological deficits. Demographic, clinical, and laboratory parameters were evaluated using SPSS version 24.0, with statistical significance considered at p<0.05. Results: Asymptomatic fractures were identified in 74 participants (25.6%). Affected individuals were significantly older (46.3±9.8 versus 36.1±10.4 years; p<0.001) and exhibited longer disease duration (14.2±7.1 versus 9.8±6.3 years; p<0.001). Prior falls within twelve months (27.0% versus 14.9%; p=0.018) and elevated C-reactive protein levels >6 mg/L (48.6% versus 35.3%; p=0.041) were independently associated with fracture presence. The thoracolumbar junction harbored 47.3% of lesions, with mild grade one deformities comprising 62.2% of cases. Conclusion: Occult vertebral compression fractures represent a frequent complication in ankylosing spondylitis, driven by disease chronicity, mechanical trauma, and persistent inflammation. Targeted imaging protocols and proactive fall prevention strategies should be prioritized for high-risk patients.