Jeremiah F. Ling

Purpose To review and compare biomechanical properties between S2 alar-iliac (S2AI) screws and traditional iliac screws for spinopelvic fixation. Methods A systematic review was performed according to PRISMA guidelines. All clinical, cadaveric, and finite-element model (FEM) studies that compared the biomechanical properties between S2AI screws and traditional iliac screws were included. Study methodological quality for cadaveric studies were analyzed using the Quality Appraisal for Cadaveric Studies (QUACS) scale. Results Eight studies (4 cadaveric, 4 FEM) analyzing 58 S2AI screws and 48 traditional iliac screws were included. According to QUACS, the overall methodological quality was “moderate to good” for all four cadaveric studies. All four cadaveric studies found no difference in biomechanical stiffness, screw toggle, rod strain, and/or load-to-failure between the S2AI screws and traditional iliac screws for spinopelvic fixation. All four FEM studies found that S2AI screws were associated with lower implant stresses compared to traditional iliac screws. Conclusions There is moderate biomechanical evidence to suggest that there is no significant difference in stability and stiffness between S2AI screws and traditional iliac screws for spinopelvic fixation. However, there is some evidence to support that the placement of S2AI screws may have lower implant stresses on the overall lumbosacral instrumentation compared to traditional iliac screws.

Purpose To review and compare clinical and radiologic outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) for the treatment of Lenke type 5 adolescent idiopathic scoliosis (AIS). Methods A systematic review was performed according to Preferred reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. All level I–III evidence studies investigating the clinical and radiologic outcomes of ASF and PSF for the treatment of Lenke type 5 AIS were included. Results Nine studies (285 ASF patients, 298 PSF patients) were included. ASF was associated with a significantly lower number of levels fused compared with PSF (p < 0.01) with similar immediate and long-term coronal deformity correction (p = 0.16; p = 0.12, respectively). PSF achieved a better correction of thoracic hypokyphosis in one study and lumbar hypolordosis in three studies. PSF was associated with a significant shorter length of stay (LOS) compared with ASF (p < 0.01). One long-term study demonstrated a significantly higher rate of proximal junctional kyphosis (PJK) with PSF compared with ASF. There were no significant differences in major complication or re-operation rates. Conclusion For the treatment of Lenke type 5 AIS, there is moderate evidence to suggest that ASF requires a lower number of instrumented levels to achieve similar immediate and long-term coronal deformity correction compared with PSF. There is some evidence to suggest that PSF may achieve better thoracic and lumbar sagittal deformity correction compared with ASF. There is some evidence to suggest a higher incidence of PJK at long-term follow-up with PSF compared with ASF. ASF is associated with a longer post-operative LOS compared with PSF.

This systematic review determines the efficacy and safety of duloxetine for chronic low back pain (CLBP). We queried the PubMed, SCOPUS, and Ovid MEDLINE databases. All level I and II randomized controlled studies published in the English language investigating the efficacy of duloxetine for chronic low back pain were included. Five studies (832 duloxetine-treated patients, 667 placebo-treated patients, and 41 duloxetine and placebo crossover analysis patients) were analyzed. One study was level I evidence and four studies were level II evidence. All five studies reported statistically significant improvements in more than one back-pain-specific clinical outcome score with duloxetine versus placebo. Four studies found that duloxetine 60 mg daily leads to one or more statistically significant improvements versus placebo in Brief Pain Inventory Severity (BPI-S) scores. All five studies found no significant difference in serious adverse events (AEs) between the duloxetine and placebo groups. One study found a higher rate of total AEs among the duloxetine 120 mg group versus the placebo group; however, the same study did not find a significant difference in total AEs among duloxetine 20 mg and 60 mg groups versus placebo. Duloxetine is a safe and effective first-line option for the treatment of CLBP. Current studies demonstrate that 60 mg taken once daily has the highest efficacy for reducing pain and disability while minimizing minor adverse effects. Further randomized controlled trials with long-term follow-up are necessary to determine its long-term effects.