BACKGROUND: Deep Vein Thrombosis (DVT) represents a significant complication following orthopedic injuries, particularly patellar fractures. Despite the prevalence, comprehensive studies assessing the incidence rates and identifying specific risk factors in patellar fracture patients are limited. METHODS: This retrospective analysis reviewed electronic medical records from 3311 patients treated for patellar fractures at two tertiary hospitals between November 2013 and January 2023. The study focused on patient demographics, fracture characteristics, comorbidities, and laboratory parameters to evaluate the incidence and predictors of DVT. DVT prophylaxis measures and diagnostic criteria, including Doppler Ultrasound Scans, were rigorously applied. RESULTS: In patients with patellar fractures, the DVT incidence was 30.8%, with 1,790 clots identified in 1,021 diagnosed individuals, predominantly on the injured side (96.7%), and a minor portion on the uninjured side (3.2%). Key risk factors included older age (P<
0.001, OR = 1.038), the presence of open injuries (P = 0.002, OR = 1.521), multiple injuries (P<
0.001, OR = 3.623), and prolonged time from injury to surgical treatment (P<
0.001, OR = 1.097). Conversely, higher levels of albumin (ALB) (P = 0.029, OR = 0.983) and sodium (Na) (P = 0.028, OR = 0.971) were identified as protective factors against DVT. Besides, ROC curve analysis revealed that the age of 52 years and a duration of 4 days from injury to surgery serve as predictive cut-off values for assessing the risk of DVT. CONCLUSION: Our study investigates the incidence of thrombosis in patellar fracture patients and identifies key risk factors for DVT, including age, open and multiple injuries, and the time from injury to surgery. Additionally, we highlight sodium and albumin levels as protective factors. By establishing threshold values for age and surgical delay, our findings improve DVT risk assessment, facilitating earlier and more targeted interventions.