Results. A minimum of 12-month follow-up was achieved in 50 patients. The average operative time was 90 minutes (range, 50-160 minutes). The mean bone graft volume was 4.8 cm(3) (range, 3.2-10.6 cm3). The intraoperative mean blood loss was 100 mL (range, 50-180 mL). Forty-two patients all had at least one American Spine Injury Association grade neurologic improvement

on final follow-up observation; there were no surgery-related complications. The mean anterior height of vertebral body was 53.2% (range 25%-78%) before surgery, 93.6% (range 78%-104%) after surgery, and 94% (range 79%-103%) at final follow-up. The preoperative Cobb angle of the primary curve averaged 30.7 degrees (range 8 degrees-67 degrees), and

corrected to 4.5 degrees (range 0 degrees-12.0 degrees) immediately after surgery, There were statistically significant (P < 0.01) among them before and after operation. There CX 5461 was no instrumentation failure or measurable loss of sagittal curve and vertebral height correction in any cases.

Conclusion. The new technique by combination check details of percutaneous external transpedicular fixation and transpedicular bone grafting is a feasible, safe, useful, efficient, and minimally invasive method to treat thoracolumbar fractures. It is a reasonable alternative method to other minimally invasive techniques of surgical management of the thoracolumbar fractures.”
“When used by itself, polyethylene imine (PEI) does not perform well as cement fluid loss additive. Its combination with acetone formaldehyde sulfite (AFS) polycondensate, however, exhibits excellent filtration control. The mechanism underlying this synergistic effect was studied and the conditions producing best results were determined.

For optimum performance, PEI and AFS must be reacted with each other to yield a polyelectrolyte complex (PEC) (d similar to 5-10 mu m), which effectively plugs the pores of the cement filter cake. Composition, size, and effectiveness of the PEC are strongly influenced by the anionic charge EPZ5676 concentration amount of the AFS dispersant. Ionic interactions between cationic imine functionalities of PEI and anionic sulfonate groups existing in AFS were confirmed by conductivity, infrared, zeta potential, and particle size measurements. For AFS samples possessing different degrees of sulfonation, the largest particle size and hence best fluid loss performance of the PEC was found to occur at a PEI: AFS molar ratio, which corresponds to neutral charge. Occurrence of large PEC particles (d similar to 5 mu m) within the cement filter cake pores was visualized by scanning electron microscopy, and their stability in highly alkaline cement pore solution was confirmed by particle size measurement. Other anionic polyelectrolytes may be used to yield such PECs with PEI to provide effective fluid loss control for cement slurries.