RESUMO
Objective To investigate the setting property and compressive strength of β-TCP (β-tricalcium phosphate)/α-CSH (α-calcium sulphate hemihydrate) combined bone graft. Method β TCP/α CSH combined bone graft and distilled water were mixed with different ratio: 1 g∶0.1 mL、1 g∶0.2 mL、1 g∶0.3 mL、1 g∶0.4 mL、1 g∶0.5 mL, respectively. The initial setting time (Ti), final setting time (TF), compressive strength were recorded, and the X-ray diffraction (XRD) and the scanning electron microscope (SEM) were examined. Results The initial and final setting time of combined bone graft increased along with the increase of solid/liquid ratio. The Ti and TF were (4.6±1.3) min and (13.1±2.9) min respectively when the solid/liquid ratio was 1 g∶0.2 mL. The average compressive strength was 7.86 MPa in one day after setting, which was about two times higher than that of β-TCP alone. The XRD results showed that no other materials were produced except that α-CSH was transformed to CSD in the setting process. The SEM results indicated that thick CSD granules were adhered to the porous surfaces of β-TCP granules after setting. Conclusions The setting time and compressive strength of β-TCP/α-CSH combined bone graft could be adjusted by the different solid/liquid ratio.
RESUMO
Objective: To analyze the clinical outcomes of the locking compression plate(LCP) fixation for the unstable sacral fracture. Methods: Nine patients with unstable sacral fracture were treated with locking compression plate fixation in our department,including 7 males and 2 females,with an average age of 34.8 years (ranged from 25 to 49 years). AO classification system found 1 B1, 4 B2, 2 B3 and 2 C1 type. Dennis classification found 6 I section sacral fracture and 3 II section sacral fracture. Incisions (6-8 cm) were made from each side of superior iliac spine to ipsilateral inferior iliac spine along iliac crest. After the fractures or dislocations were exposed and reduced, LCPs were chosen and remodeled. The iliosacral posterior ligaments were restored if injured. The LCP was pushed cutaneously to the other incision, placed on both dorsal ilia and fixed with locking screws. Each side of postal LCP was fixed with 3 locking screws for effective fixation. The reduction and fixation of fractures or dislocation were assured by radiostereoscopy. The operations lasted 45 min averagely (ranged from 30-80 minutes) and no patient needed blood transfusion. The average X-ray exposure period was 4 min(from 2-10 minutes). Results: All the patients were followed-up for a mean of 13.8 months,ranged from 6 months to 21 months. There was no iatrogenic nerve injury. The function and the feeling of sacroiliac joint and low extremities recovered to normality. According to the Majeed standards, the results were excellent in 4,good in 4,and fair in 1. Conclusion: The locking compression plate fixation is a simple and effective treatment for the unstable sacral fractures, with less trauma and complications.