This study aimed to investigate the incidence and risk factors for deep vein thrombosis (DVT) in patients with pelvic and acetabular fractures. Patients with pelvic or acetabular fractures were included. Demographic data, fracture classification, time to surgery, and d -dimer levels at admission and one day after surgical intervention were recorded. Duplex ultrasonography was performed in the lower extremities for DVT evaluation. All patients received mechanical and chemical thromboprophylaxis. One hundred ten patients with a mean age of 44.2 ± 13.8 years were included. There were 48 patients with pelvic fractures and 62 patients with acetabular fractures. Thirty-two (29.09%) patients sustained DVT; 21 (19.09%) patients exhibited proximal thrombosis, and 3 patients suffered pulmonary embolism. The incidence of DVT in patients with acetabular fractures was significantly higher than that of patients with pelvic fractures (χ 2 = 4.42, P = .04). The incidence of proximal DVT was significantly higher in patients with complex acetabular fractures than in patients with simple acetabular fractures (χ 2 = 6.65, P = .01). Multivariate analysis showed that age older than 60 years, associated injuries, and the time to surgery longer than 2 weeks were independent risk factors ( P < .05). Despite mechanical and chemical thromboprophylaxis, the risk of DVT in patients with pelvic and acetabular fractures is still very high, and most of the thromboses were localized proximally. The risk of DVT is higher in patients older than 60 years, in those with associated injuries, and when the time from injury to operation is more than 2 weeks.

This paper presents the Hencky bar-chain model (HBM) for buckling and vibration analyses of Euler–Bernoulli beams with elastic end restraints. The Hencky bar-chain comprises rigid beam segments (of length a = L/n where L is the total length of beam and n the number of beam segments) connected by frictionless hinges with elastic rotational springs of stiffness EI/a where EI is the flexural rigidity of the beam. The elasticity and the mass of the beam are concentrated at the hinges with rotational springs. The key contribution of this paper lies in the modeling of the elastic end restraints of the Hencky bar-chain that will simulate the same buckling and vibration results as that furnished by the first-order central finite difference beam model (FDM) which was earlier shown to be analogous to the HBM. The establishment of such a physical discrete beam model allows one to obtain solutions for beam-like structure with repetitive cells (or elements) as well as to calibrate the Eringen's coefficient e0 in the nonlocal beam theory that captures the small length scale effect.

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