2. Materials and Methods 2.1. Study http://www.selleckchem.com/products/Rapamycin.html Patients A consecutive prospective series of 15 osteoporotic patients operated on between March 2010 and July 2011 (12 female, 3 male, mean age 71.2 years (60�C88)) with osteoporotic compression/burst fracture (4 patients), degenerative spondylolisthesis (5 patients), and spinal and/or foraminal stenosis (6 patients) underwent MIS posterior pedicle arthrodesis with or without interbody fusion with PMMA cement augmentation of pedicle screws. All patients were included in this study based on the results of a DEXA bone mineral density examination showing osteopenia to severe osteoporosis according to the WHO criteria. The mean T score was ?2.7 (?2.1 to ?4.1). Figure 1 shows the new model of cannulated and fenestrated pedicle screw featuring fenestrations that allows cement injection through the implant.

Expedium fenestrated screws (DePuy Spine, Johnson & Johnson) was used in all cases. Figure 1 The titanium Expedium fenestrated screw (VIPER MIS Spine System, DePuy Spine, Johnson & Johnson) is a polyaxial, fully cannulated with six fenestrations in the grooves of the distal portion of the thread and an opening at the distal tip. Inclusion criteria were as follows: (1) patient over 60 years of age; (2) demonstration by DEXA bone mineral density examination of osteopenia to severe osteoporosis according to the WHO criteria; (3) evidence of spinal trauma, degenerative or deformative spinal disorders with an indication of stabilization and realignment of the thoracolumbar or lumbar spine.

Patients were excluded from the study in case of (1) previous history of spinal infection; (2) spondylolisthesis > grade III; (3) severely increased risk for surgery under general anaesthesia due to cardiovascular, Batimastat pulmonary, or other concomitant diseases. The mean follow-up period was 13,3 months (6 to 24 months). Table 1 shows the demographic characteristics of the included patients and their clinical data. All patients were evaluated using CT scan or MRI to define the surgical indication and to measure the pedicle diameter and length prior to surgery. Table 1 Clinical data of patients undergoing fenestrated pedicle screw augmentationa through minimally invasive approach. In all cases, preoperative clinical data were collected: pain intensity was evaluated by the VAS and the function was assessed by the ODI [17]. 2.2. Surgical Technique and Instrument All the patients were operated under general anaesthesia. A ��flash�� dose of antibiotic (cephalosporin) was injected intravenously 1/2 hour before the incision and renewed once the surgery lasted longer than 3 hours.