Therefore, in this population, a major surgical intervention is being applied in a highly compromised patient population [5, 6]. To combat these challenges, modern surgeons have begun to apply minimally invasive surgery (MIS) techniques to address ASD [7�C9]. MIS techniques have been associated with reduced intraoperative blood selleck inhibitor loss, lower infection rates, and quicker mobilization, all of which would be highly desirable in the ASD population [10]. While the early MIS fusion experience has focused on one- and two-level procedures for degenerative spinal disease, a variety of techniques have been developed more recently for use in ASD. One major advance in spinal fixation has been the application of iliac fixation.

Pelvic fixation is an important tool in the armamentarium of the modern spinal surgeon, as screws or bolts of a large diameter and length can be placed safely for caudal anchoring and extend anterior to the spine in the sagittal plane and lateral to it in the coronal plane. Iliac fixation is useful in ASD for long instrumentation constructs, sagittal and coronal deformity corrections, and stabilization of low sacropelvic instability [11�C13]. We previously published a technique for percutaneous iliac screw fixation [14]. This paper builds upon that experience with the application of this technique in the setting of ASD. 2. Methods 2.1. Patient Population A consecutive series of 10 patients were treated over an 18-month period at a single institution. All patients underwent MIS treatment of ASD using expandable interbody cage placement and percutaneous pedicle and iliac screws.

ASD was defined as a Cobb angle greater than 20��. All deformities were rigid with less than 10�� of motion in the coronal or sagittal planes across the deformity segments on flexion, extension, and lateral bending films. All patients had also failed conservative measures and had severe back and/or back and leg pain with distance limited gait. The accuracy of iliac screw insertion was examined using postoperative spiral CT scanning to confirm that screws were entirely within the bony confines. 2.2. Surgical Technique Patients were positioned prone on the Jackson table so that the pelvis would not be obscured on fluoroscopic imaging by the base of the operating table. Pre-operative imaging, including 3 D reconstructed CT scans of the pelvis, was helpful for planning screw placement trajectories and to validate the fluoroscopic data in the operating room.

Iliac cannulation is performed prior to pedicle screw cannulation to maximize the ability to image the pelvis. In addition, the decompression, osteotomies, and interbody fusion are accomplished prior to screw placement. For each side of the iliac crest, Dacomitinib the fluoroscope is angled in the sagittal and coronal planes in the obturator outlet view so that the X-ray beams are approximately parallel to both the inner and outer tables of the ilium (Figure 1).