Revision by S2-alar-iliac instrumentation reduces caudal screw loosening while improving sacroiliac joint pain-a group comparison study

Biomechanical study and preliminary application of percutaneous retrograde sacral alar-iliac screw for fixation of sacroiliac joint with low bone density

BACKGROUND

The Sacral alar-iliac screw (SAIS) has stronger stability for sacroiliac joint fixation compared to the classical sacroiliac screw, making it particularly suitable for osteoporotic patients. However, the spinous process can hinder its percutaneous implantation. To address this, we developed a percutaneous retrograde SAIS (RSAIS) technique. This study aimed to explore the stability and preliminary application effects of percutaneous RSAIS for fixation of sacroiliac joint with low bone density.

METHODS

A Tile type C fracture was simulated in fifteen artificial pelvises with low bone density and assigned to three groups. Each group received posterior fixation using one of the following: one sacroiliac screw (SIS) on each side, one transsacral-transiliac screw (TSTIS) on both sides, or one RSAIS on each side. Axial stiffness and maximum load to failure were analyzed. Additionally, two patients with sacroiliac joint pain (SIJP) and three patients with Tile type C pelvic fractures were treated with percutaneous RSAIS fixation. Four males and one female, aged 56 to 68 years with a T-value of -1.6 to -2.5 SD. The study observed screw insertion time, X-ray fluoroscopy time, screw position (Smith criterion), pain (VAS), and functional recovery (ODI and Majeed scores).

RESULTS

RSAIS stiffness and maximum load were significantly greater than those of TSTIS and SIS (p < 0.05). The average insertion time was 30 min, intraoperative bleeding averaged 16 ml, and fluoroscopy time was 55 s per RSAIS placement. There were no surgery-related complications, and all screw positions were excellent. At 7-20 months postoperative follow-up, the VAS score recovered from preoperative 5.6-1.6, the ODI improved from 50.4 to 17, and the Majeed score for patients with pelvic fractures recovered from 59.7 to 81. No screw loosening was observed.

CONCLUSION

RSAIS fixation stability for sacroiliac joints with low bone density is superior to SIS and TSTIS. The screw placement is simple, safe, and provides satisfactory therapeutic effects, making it suitable for patients with low bone density.

Utility of minimally invasive percutaneous arthrodesis of the sacroiliac joint for the treatment of low back pain: systematic review of the literature

BACKGROUND

The surprising increase observed in recent years in the use of minimally invasive sacroiliac joint arthrodesis techniques as a treatment for low back pain justifies an objective review of this results.

PURPOSE

carry out a systematic review of the literature to evaluate the clinical results of patients with low back pain treated with percutaneous arthrodesis of the SIJ.

STUDY DESIGN

Systematic review.

METHODS

Systematic search of the medical literature. The words used in the Search were: "Hollow screw system", "percutaneous sacroiliac joint stabilization", "sacroiliac joint", "minimally invasive", "sacroiliac pain", "sacroiliac dysfunction". With logical connectors such as "and", "not" and "or".

DATABASES

Pubmed, Scopus, Embase, Ovid, EBSCO host and google scholar. The search extended from the beginning of the databases until September 2024. The "Rayyan" program was used to collect the information and facilitate the analysis process.

INCLUSION CRITERIA

Systematic review from the literature, clinical trials, observational studies and case series. They followed PRISMA principles.

RESULTS

661 articles were found, of which 108 articles were duplicates. The criteria (Inclusion/Exclusion) were applied to the 553 articles identified based on the independent reading of the summaries by each of the authors on the Rayyan platform and 434 articles were excluded. The 119 selected articles were completely reviewed to finally obtain 102 articles included in the review. Epidemiological data were extracted into an Excel table, methodological and related to clinical results and safety of procedures made. The Prisma checklist for systematic reviews was applied in each article. The epidemiological quality of the articles was evaluated based on the checklists STROBE and CONSORT. The results regarding clinical improvement were overwhelming. However, most of the studies were sponsored by industry and with a limited population and follow-up not always prolonged.

CONCLUSIONS

Although the clinical results regarding the effectiveness of SIJ fusion are forceful for their effectiveness, we recommend considering some aspects for their analysis and especially long-term studies.

S2 alar-iliac screws are superior to traditional iliac screws for spinopelvic fixation in adult spinal deformity: a systematic review and meta-analysis

PURPOSE

Spinopelvic fixation (SPF) using traditional iliac screws has provided biomechanical advantages compared to previous constructs, but common complications include screw prominence and wound complications. The newer S2 alar-iliac (S2AI) screw may provide a lower profile option with lower rates of complications and revisions for adult spinal deformity (ASD). The purpose of this study was to compare rates of complications and revision following SPF between S2AI and traditional iliac screws in patients with ASD.

METHODS

A PRISMA-compliant systematic literature review was conducted using Cochrane, Embase, and PubMed. Included studies reported primary data on adult patients undergoing S2AI screw fixation or traditional IS fixation for ASD. Primary outcomes of interest were rates of revision and complications, which included screw failure (fracture and loosening), symptomatic screw prominence, wound complications (dehiscence and infection), and L5-S1 pseudarthrosis.

RESULTS

Fifteen retrospective studies with a total of 1502 patients (iliac screws: 889 [59.2%]; S2AI screws: 613 [40.8%]) were included. Pooled analysis indicated that iliac screws had significantly higher odds of revision (17.1% vs 9.1%, OR = 2.45 [1.25-4.77]), symptomatic screw prominence (9.9% vs 2.2%, OR = 6.26 [2.75-14.27]), and wound complications (20.1% vs 4.4%, OR = 5.94 [1.55-22.79]). S2AI screws also led to a larger preoperative to postoperative decrease in pain (SMD = - 0.26, 95% CI = -0.50, - 0.011).

CONCLUSION

The findings from this review demonstrate higher rates of revision, symptomatic screw prominence, and wound complications with traditional iliac screws. Current data supports the use of S2AI screws specifically for ASD.

PROSPERO ID

CRD42022336515.

LEVEL OF EVIDENCE

III.

Incidence and Risk Factors of the Caudal Screw Loosening after Pelvic Fixation for Adult Spinal Deformity: A Systematic Review and Meta-analysis

The purpose of this study was to assess the factors affecting caudal screw loosening after spinopelvic fixation for adult patients with spinal deformity. This meta-analysis calculated the weighted mean difference (WMD) and odds ratio (OR) using Review Manager ver. 5.3 (RevMan; Cochrane, London, UK). The loosening group was older than the control group (WMD, 2.17; 95% confidence interval [CI], 0.48-3.87; p=0.01). The S2 alar-iliac (S2AI) could prevent the caudal screw from loosening (OR, 0.43; 95% CI, 0.20-0.94; p=0.03). However, gender distribution (p=0.36), the number of fusion segments (p=0.24), rod breakage (p=0.97), T-score (p=0.10), and proximal junctional kyphosis (p=0.75) demonstrated no difference. Preoperatively, only pelvic incidence (PI) in the loosening group was higher (WMD, 5.08; 95% CI, 2.71-7.45; p<0.01), while thoracic kyphosis (p=0.09), lumbar lordosis (LL) (p=0.69), pelvic tilt (PT) (p=0.31), pelvic incidence minus lumbar lordosis (PI-LL) (p=0.35), sagittal vertical axis (SVA) (p=0.27), and T1 pelvic angle (TPA) demonstrated no difference (p=0.10). PI-LL (WMD, 6.05; 95% CI, 0.96-11.14; p=0.02), PT (WMD, 4.12; 95% CI, 0.99-7.26; p=0.01), TPA (WMD, 4.72; 95% CI, 2.35-7.09; p<0.01), and SVA (WMD, 13.35; 95% CI, 2.83-3.87; p=0.001) were higher in the screw loosening group immediately postoperatively. However, TK (p=0.24) and LL (p=0.44) demonstrated no difference. TPA (WMD, 8.38; 95% CI, 3.30-13.47; p<0.01), PT (WMD, 6.01; 95% CI, 1.47-10.55; p=0.01), and SVA (WMD, 23.13; 95% CI, 12.06-34.21; p<0.01) were higher in the screw loosening group at the final follow-up. However, PI-LL (p=0.17) demonstrated no significant difference. Elderly individuals were more susceptible to the caudal screw loosening, and the S2AI screw might better reduce the caudal screw loosening rate than the iliac screws. The lumbar lordosis and sagittal alignment should be reconstructed properly to prevent the caudal screw from loosening. Measures to block sagittal alignment deterioration could also prevent the caudal screw from loosening.

Clinicoradiological Outcomes and Complication Profiles of Bilateral Dual Sacral-Alar-Iliac Screws versus Bilateral Single Sacral-Alar-Iliac Screws in Patients with Spinal Deformity Who Underwent Grade 3 or 4 Spinal Osteotomies: A Retrospective Comparative Study

OBJECTIVE

To compare short-term clinical and radiological outcomes and complication profiles between bilateral dual sacral-2-alar-iliac (S2AI) screw and bilateral single S2AI screw fixation techniques in patients who underwent grade 3 or 4 spinal osteotomies.

METHODS

A retrospective review of 83 patients treated with bilateral dual S2AI screws and 32 patients treated with bilateral single S2AI screws was conducted between 2018 and 2020 with a minimum 1-year follow-up. Clinical and radiological outcomes of patients and incidence of perioperative complications, including rod breakage, screw dislodgment, proximal junctional kyphosis, proximal junctional failure, need for reoperation, and systemic adverse effects, were collected and statistically compared between the groups.

RESULTS

With a mean follow-up of 18.2 months, rod fracture (6.0% vs. 18.7%, P = 0.03), screw dislodgment (0 vs. 12.5%, P < 0.01), and S2AI screw loosening (1.2% vs. 18.7%, P < 0.01) were significantly lower in the dual S2AI screws group than in the single S2AI screws group. However, the reoperation rate was similar between the 2 groups (24.1% vs. 34.3%, P = 0.26). No significant differences in clinical and radiological outcomes as well as proximal junctional kyphosis (10.8% vs. 18.7%, P = 0.25) and proximal junctional failure (9.6% vs. 18.7%, P = 0.18) were identified between the 2 groups.

CONCLUSIONS

The dual S2AI screw fixation technique showed more advantages over the single S2AI screw fixation technique with reduced incidence of screw dislodgment, rod fractures, and sacral-alar-iliac screw loosening.