Ilio-lumbar Fixation—The Amrita Technique

Abstract

Our technique of ilio-lumbar fixation provides a stable and simple alternative to reconstruct potentially devastating instability of the lumbosacral junction. The 2 iliac screws, when used as described, make the procedure technically easier, reduce the hardware prominence without compromising the stability to construct and provide adequate bone graft.

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].…”

“…Anatomic and radiographic studies have confirmed that there are two columns in the upper and lower areas of the ilium where the cancellous bone is found in abundance [6,[9][10][11][12]. The upper iliac column stands from the posterior superior iliac spine (PSIS) to the highest portion of the iliac crest; the lower column is located in the area from PSIS to the anterior inferior iliac spine (AIIS).…”

“…The upper iliac column stands from the posterior superior iliac spine (PSIS) to the highest portion of the iliac crest; the lower column is located in the area from PSIS to the anterior inferior iliac spine (AIIS). These two columns contain a linear bony area which can provide sufficient anchoring for the placement of iliac screws [6,[9][10][11][12]. Importantly, at the level of great sciatic notch (GSN) of the lower iliac column, there is a narrow, cortex-rich point which can provide a rigid purchase for the iliac screws [9,12].…”

“…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.…”

“…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. However, the difference in biomechanical function between the use of dual and single iliac screws in lumbo-iliac fixation construct still remains unclear.…”