The freehand technique for S2-alar-iliac screw placement: a review of current literature in adult spinal deformity

Purpose: Sacropelvic fixation continues to present challenges when involved in the adult spinal deformity correction. The S2 alar iliac (S2AI) fixation is commonly used in sacropelvic fixation. Several techniques, including intraoperative navigation and freehand technique, were used for S2AI screws placement. The aim of this study is to analyze the anatomic parameters for S2AI screw trajectory in Asian population and introduce a novel technique described as a three-dimensional printed template guided technique (TGT). Meanwhile, the accuracy and safety of this technique were compared with the conventional freehand technique. Methods: The S2AI trajectory parameters were measured in 100 Asian adult volunteers. Parameters were compared between different genders. Forty-eight adult patients who underwent S2AI screw placement were reviewed: 28 patients received freehand technique and 20 patients received TGT technique. Postoperative computed tomography was used to assess the accuracy of screw trajectory and cortex violation-related complications were recorded. Results: The cephalocaudal angles (CAs), maximal length of screw pathway, narrowest width of pathway within the iliar teardrop, distance from the center of teardrop to sciatic notch, and distance of the start point distal to S1 dorsal foramen showed significant gender-related difference ( p < 0.05). All 48 patients were placed S2AI screws bilaterally (40 screws in TGT vs. 56 screws in freehand). One screw penetrated iliac cortex in the TGT group but 10 screws penetrated iliac cortex in the freehand group (3% vs. 17.9%) ( p < 0.05). Conclusion: Approximately 30–35° of CA and 39° mediolateral angle are appropriate for S2AI screw placement in Asian patients. Either freehand or TGT technique is safe for S2AI screw placement. TGT technique is more accurate compared with the conventional freehand technique. Trial registration: This is a retrospective study.

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S2 alar iliac screw placement under robotic guidance for adult spinal deformity patients: technical note

European Spine Journal ◽

10.1007/s00586-017-5012-z ◽

2017 ◽

Vol 26 (8) ◽

pp. 2198-2203 ◽

Cited By ~ 10

Author(s):

Seung-Jae Hyun ◽

Ki-Jeong Kim ◽

Tae-Ahn Jahng

Keyword(s):

Spinal Deformity ◽

Adult Spinal Deformity ◽

Technical Note ◽

Screw Placement ◽

Iliac Screw

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Comparison of Radiographic And Clinical Outcomes Observed After Adult Spinal Deformity Correction Using Iliac Screw Versus S2-Alar-Iliac Screw

10.21203/rs.3.rs-492643/v1 ◽

2021 ◽

Author(s):

Qiang Luo ◽

Yong-Chan Kim ◽

Ki-Tack Kim ◽

Kee-Yong Ha ◽

Joonghyun Ahn ◽

...

Keyword(s):

Clinical Outcomes ◽

Spinal Deformity ◽

Lumbar Lordosis ◽

Adult Spinal Deformity ◽

Deformity Correction ◽

Postoperative Change ◽

Iliac Screw ◽

Vas Scores ◽

Correction Surgery

Abstract Background: To date, there is a paucity of reports clarifying the change of spinopelvic parameters in patients with adult spinal deformity (ASD) who underwent long segment spinal fusion using iliac screw (IS) and S2-alar-iliac screw (S2AI) fixation.Methods: A retrospective review of consecutive patients underwent deformity correction surgery for ASD between 2013 and 2017 was performed. Patients were divided into two groups based on whether IS or S2AI fixation was performed. All radiographic parameters were measured preoperatively, immediately postoperatively, and the last follow-up. Demographics, intraoperative and clinical data were analyzed between the two groups. Additionally, the cohort was subdivided according to the postoperative change in pelvic incidence (PI): subgroup (C) was defined as change in PI ≥5° and subgroup (NC) with change <5°. In subgroup analyses, the 2 different types of postoperative change of PI were directly compared.Results: A total of 142 patients met inclusion criteria: 111 who received IS and 31 received S2AI fixation. The IS group (65.6 ± 26, 39.8 ± 13.8) showed a significantly higher change in lumbar lordosis (LL) and upper lumbar lordosis (ULL) than the S2AI group (54.4 ± 17.9, 30.3 ± 9.9) (p<0.05). In subgroup (C), PI significantly increased from 53° preoperatively to 59° postoperatively at least 50% of IS cohort, with a mean change of 5.8° (p<0.05). The clinical outcomes at the last follow-up were significantly better in IS group than in S2AI group in terms of VAS scores for back and leg. The occurrence of sacroiliac joint pain and pelvic screw fracture were significantly greater in S2AI group than in IS group (25.8% vs 9%, p<0.05) and (16.1% vs 3.6%, p<0.05).Conclusions: IS fixation showed a greater change in LL and ULL than S2AI fixation in ASD surgery. PI may be changed under certain circumstances.

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The Incidence of Iliac Screw-Related Complications After Long Fusion Surgery in Patients with Adult Spinal Deformity

Spine ◽

10.1097/brs.0000000000004276 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Tomohiro Banno ◽

Tomohiko Hasegawa ◽

Yu Yamato ◽

Go Yoshida ◽

Hideyuki Arima ◽

...

Keyword(s):

Spinal Deformity ◽

Adult Spinal Deformity ◽

Fusion Surgery ◽

Iliac Screw

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S-1 and S-2-alar-iliac screw fixation via intraoperative navigation

Neurosurgical FOCUS ◽

10.3171/2016.2.focusvid.1693 ◽

2016 ◽

Vol 41 (videosuppl1) ◽

pp. 1

Author(s):

Martin H. Pham ◽

Andre M. Jakoi ◽

Patrick C. Hsieh

Keyword(s):

Spinal Deformity ◽

Screw Fixation ◽

Adult Spinal Deformity ◽

Intraoperative Navigation ◽

Case Presentation ◽

Adult Deformity ◽

Sacropelvic Fixation ◽

Fixation Techniques ◽

Iliac Screw ◽

Bicortical Screw

Adult deformity patients often require fixation to the sacrum and pelvis for construct stability and improved fusion rates. Although certain sacropelvic fixation techniques can be challenging, the availability of intraoperative navigation has made many of these techniques more feasible. In this video case presentation, the authors demonstrate the techniques of S-1 bicortical screw and S-2-alar-iliac screw fixation under intraoperative navigation in a 67-year-old female. This instrumentation placement was part of an overall T-10–pelvis construct for the correction of adult spinal deformity.The video can be found here: https://youtu.be/3HZo-80jQr8.

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Three-Dimensional Printing for Preoperative Planning and Pedicle Screw Placement in Adult Spinal Deformity: A Systematic Review

Global Spine Journal ◽

10.1177/2192568220944170 ◽

2020 ◽

pp. 219256822094417

Author(s):

Cesar D. Lopez ◽

Venkat Boddapati ◽

Nathan J. Lee ◽

Marc D. Dyrszka ◽

Zeeshan M. Sardar ◽

...

Keyword(s):

Systematic Review ◽

Spinal Deformity ◽

Adult Spinal Deformity ◽

Three Dimensional ◽

Deformity Correction ◽

Screw Placement ◽

Spinal Deformities ◽

Three Dimensional Printing ◽

Significant Difference ◽

Dimensional Printing

Study Design: Systematic review. Objectives: This current systematic review seeks to identify current applications and surgical outcomes for 3-dimensional printing (3DP) in the treatment of adult spinal deformity. Methods: A comprehensive search of publications was conducted through literature databases using relevant keywords. Inclusion criteria consisted of original studies, studies with patients with adult spinal deformities, and studies focusing on the feasibility and/or utility of 3DP technologies in the planning or treatment of scoliosis and other spinal deformities. Exclusion criteria included studies with patients without adult spinal deformity, animal subjects, pediatric patients, reviews, and editorials. Results: Studies evaluating the effect of 3DP drill guide templates found higher screw placement accuracy in the 3DP cohort (96.9%), compared with non-3DP cohorts (81.5%, P < .001). Operative duration was significant decreased in 3DP cases (378 patients, 258 minutes) relative to non-3DP cases (301 patients,272 minutes, P < .05). The average deformity correction rate was 72.5% in 3DP cases (245 patients). There was no significant difference in perioperative blood loss between 3DP (924.6 mL, 252 patients) and non-3DP cases (935.6 mL, 177 patients, P = .058). Conclusions: Three-dimensional printing is currently used for presurgical planning, patient and trainee communication and education, pre- and intraoperative guides, and screw drill guides in the treatment of scoliosis and other adult spinal deformities. In adult spinal deformity, the usage of 3DP guides is associated with increased screw accuracy and favorable deformity correction outcomes; however, average costs and production lead time are highly variable between studies.

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The lexicon of multirod constructs in adult spinal deformity: a concise description of when, why, and how

Journal of Neurosurgery Spine ◽

10.3171/2021.10.spine21745 ◽

2021 ◽

pp. 1-7

Keyword(s):

Spinal Deformity ◽

Adult Spinal Deformity ◽

Pedicle Screws ◽

Lumbosacral Junction ◽

Coronal Balance ◽

Clinical Scenarios ◽

Iliac Screw ◽

Correction Surgery ◽

Rod Fracture ◽

Concise Description

The use of multirod constructs in the setting of adult spinal deformity (ASD) began to prevent rod fracture and pseudarthrosis near the site of pedicle subtraction osteotomies (PSOs) and 3-column osteotomies (3COs). However, there has been unclear and inconsistent nomenclature, both clinically and in the literature, for the various techniques of supplemental rod implantation. In this review the authors aim to provide the first succinct lexicon of multirod constructs available for the treatment of ASD, providing a universal nomenclature and definition for each type of supplementary rod. The primary rod of ASD constructs is the longest rod that typically spans from the bottom of the construct to the upper instrumented vertebrae. The secondary rod is shorter than the primary rod, but is connected directly to pedicle screws, albeit fewer of them, and connects to the primary rod via lateral connectors or cross-linkers. Satellite rods are a 4-rod technique in which 2 rods span only the site of a 3CO via pedicle screws at the levels above and below, and are not connected to the primary rod (hence the term “satellite”). Accessory rods are connected to the primary rods via side connectors and buttress the primary rod in areas of high rod strain, such as at a 3CO or the lumbosacral junction. Delta rods span the site of a 3CO, typically a PSO, and are not contoured to the newly restored lordosis of the spine, thus buttressing the primary rod above and below a 3CO. The kickstand rod itself functions as an additional means of restoring coronal balance and is secured to a newly placed iliac screw on the side of truncal shift and connected to the primary rod; distracting against the kickstand then helps to correct the concavity of a coronal curve. The use of multirod constructs has dramatically increased over the last several years in parallel with the increasing prevalence of ASD correction surgery. However, ambiguity persists both clinically and in the literature regarding the nomenclature of each supplemental rod. This nomenclature of supplemental rods should help unify the lexicon of multirod constructs and generalize their usage in a variety of scientific and clinical scenarios.

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