Pelvic fixation for adult scoliosis

Abstract

There is growing evidence that pelvic fixation may become the standard for obtaining long fusions in adult scoliosis. Although technically challenging, in selected cases the use of four pelvic screws and/or four rods across the lumbosacral pelvis can help address pseudarthroses, implant breakage, and screw pullout secondary to osteoporosis. Ultimately, indications and techniques should be individualized to the patient and based on surgeon preference and experience.

Unilateral versus bilateral iliac screws for spinopelvic fixation: are two screws better than one?

“…Iliac screw placement was done in a standard fashion as previously described by Tumialán and Mummaneni (Table 2). 7,11,12 The iliac crest is first exposed by mobilizing the paraspinal muscles. After adequate exposure of the iliac crest is achieved, the posterior superior iliac spine (PSIS) is palpated.…”

“…To overcome this problem, many surgeons routinely use iliac (pelvic) screw fixation to supplement the sacral pedicle screws in long-segment fixation that extends to the sacrum. 2,3,5,11,12,15 The addition of iliac screws decreases lumbosacral screw strain, 6,[8][9][10] which may lower the incidence of screw pullout, L5-S1 pseudarthrosis, and sacral insufficiency fracture at S1-2. Iliac fixation screws serve as temporary scaffolding to allow for the maturation of bony fusion across the lumbosacral junction.…”

Entry zone of iliac screw fixation to maintain proper entry width and screw length

“…However, placement of the iliac screw at the prominence of the PSIS can cause screw head protrusion [3]. For this reason, it is recommended that the entry point be located deep in the PSIS along the medial aspect of the inner table of the ilium [4,5]. However, making an eccentric entry point on the PSIS can perforate the inner or outer table of the ilium during advancement, or can make the long screw unavailable for fixation [2,6,7].…”

“…In selected cases of dual iliac screw fixation on one side, pre-operative planning for the screw entry and trajectory should be mandatory, so that space to hold two screws can be prepared [4]. In minimally invasive surgeries in which percutaneous fixations of iliac and pedicle screws were used, an accurately placed entry point and trajectory should be selected under fluoroscopy for easy connection of screws and preventing screw-related complications [8,9].…”

Reviewer’s Comment concerning “Multiaxial high modularity spinopelvis (HSMP) fixation device in neuromuscular scoliosis—a comparative study” (ESJO-D-13-00331R1 by Jin-Ho Hwang, Hitesh N. Modi, Seung-Woo Suh, Jae-Hyuk Yang, Jae-Young Hong)

“…Because of the complexity and some shortcomings of this former type of fixation we ourselves described several pelvic fixations over the years: the modified Luque for Duchenne's neuromuscular scoliosis, the MW fixation for severe and rigid pelvic obliquity, the adult pelvic fixation and the four-rod techniques for sacrectomy and/or previously failed deformity surgery [2][3][4][5]. Numerous authors have also described other methods of pelvic fixation, the latest using S2 screws to achieve anchor in the sacrum and pelvis [6].…”