Minimum 5-Year Analysis of L5–S1 Fusion Using Sacropelvic Fixation (Bilateral S1 and Iliac Screws) for Spinal Deformity

Abstract

For high-grade spondylolisthesis and long adult deformity fusions to the sacrum, a montage of bilateral S1 screws and iliac screws were effective in protecting the sacral screws from failure. Pseudarthrosis at L5-S1 was manifested by rod breakage at that level. We saw no evidence of a long-term effect of the iliac screws predisposing the sacroiliac joints to degeneration at follow-up ranging from 5 to 10 years.

Biomechanical advantages of dual over single iliac screws in lumbo-iliac fixation construct

“…Iliac screw technique is a common technique adopted in treating certain typical conditions requiring long segment fixation such as in the correction of neuromuscular and adult scoliosis, reduction of high-grade spondylolisthesis, sacral fractures, and surgical treatment of sacral tumors requiring sacrectomy [1][2][3][4][5][6][7][8]. Although iliac screw fixation provides a solid foundation to restore spinal balance and to stabilize the lumbosacral junction, high rate of implant failure including screw loosening and breakage has also been reported, especially in patients with bilateral single iliac screw fixation [2,3,5,8].…”

“…Although iliac screw fixation provides a solid foundation to restore spinal balance and to stabilize the lumbosacral junction, high rate of implant failure including screw loosening and breakage has also been reported, especially in patients with bilateral single iliac screw fixation [2,3,5,8]. Moreover, complications of the distal instrumentation are often considered to be relative to lumbosacral nonunion and low back pain [3].…”

“…To improve the lumbo-iliac fixation strength, some clinical studies have proposed the use of bilateral dual iliac screw techniques for total sacrectomy in removal of sacral tumors [3,4,6,7]. Fujibayashi et al [7] proposed a dual iliac screw technique in which the double screws were all placed in the lower iliac column; whereas, Acharya et al [6] preferred insertion of dual iliac screws both in the upper and lower columns.…”

Minimally invasive lumbopelvic instrumentation for traumatic sacrolisthesis in an elderly patient

“…Prior to minimally invasive techniques, these rare fracture dislocations required open treatment with instrumentation constructs bridging the sacrolisthesis or conservative management with prolonged immobilization. Open operative constructs included transiliac bars, iliac post bolts, and iliosacral screws [7,9]. The location of the required skin incision for these large open procedures and elderly patient population made these surgical options especially prone to wound healing issues, sacral decubiti, and other postoperative morbidities secondary to prolonged immobilization.…”

“…Prophylactic antibiotics were administered. The decision was made to incorporate L5 into the instrumentation construct in order to offer additional fixation points due to the high mechanical demand at S1 [7]. Stab incisions were made over the bilateral L5 and S1 pedicles using AP fluoroscopy.…”