The Lumbar Pelvic Angle (L1PA) was introduced as a convenient intraoperative and postoperative measure of sagittal alignment. However, the utility of L1PA for short segment lumbar fusions remains incompletely understood. This study investigates the relationship between L1PA and segmental parameters of spinal alignment for short segment lumbar fusions. This retrospective analysis was conducted on adult patients with degenerative conditions undergoing primary spinal fusion surgery between L4 and S1. Patients with 35° of regional lordosis at L4-S1 postoperatively and (2) those with >5% change in Lumbar Distribution Index (LDI). Spinopelvic parameters were compared between preoperative and postoperative measurements. The study cohort included 539 patients, of which 360 (66.8%) had an L1PA change less than <5° pre- to postoperatively. Patients in both Group 1 and 2 had significant increases in the L5-S1 segmental angle (both p<.001) without a significant change at the L4-L5 segment. In Group 2, there was a significant increase in PI-LL mismatch (p<.001). In both groups there was a significant increase in L4-S1 lordosis, a relaxation in L1-L4 lordosis (both p<.001), and no significant change in total LL. This investigation assessed L1PA in over 500 patients undergoing lumbar fusion between L4 and S1 and found that despite value to the measure, important changes to spinal shape and segmental alignment may occur even in the face of Δ L1PA <5°. As such, L1PA serves as a potentially useful adjunct to clinical assessment and radiographic measurement in lumbar degenerative fusion but should not serve as a stand-alone measurement.

➢ Implant surface characteristics play a critical role in promoting osseointegration and long-term spinal fusion success. ➢ Titanium and polyetheretherketone (PEEK) are the most commonly utilized materials in interbody cages, each with distinct advantages and limitations. ➢ Surface modifications such as roughening, porosity, and hydroxyapatite coatings enhance osseointegration and early fusion outcomes. ➢ Emerging materials, including silicon nitride and porous tantalum, demonstrate favorable biological and mechanical properties but require further clinical validation. ➢ No single implant material or surface technology has shown consistent clinical superiority, highlighting the need for ongoing research and evidence-based selection.

Background: Normal saline is commonly used as a presumed inert placebo control in lumbar injection trials. However, prior studies suggest that saline injections may be associated with improvements in patient-reported outcomes, potentially confounding interpretation of comparative treatment effects. The magnitude, durability, and clinical relevance of these changes have not been systematically characterized. The primary aim of this study was to evaluate changes in patient-reported outcomes following saline injection in patients with lumbar radiculopathy and, separately, in patients with diskogenic low back pain. Methods: A systematic review of PubMed, Embase, and Google Scholar was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify randomized controlled trials (RCTs) published between 2000 and 2025 that included a saline injection arm for lumbar radiculopathy or diskogenic pain. Within-arm pre-post changes in Visual Analog Scale (VAS) pain scores and Oswestry Disability Index (ODI) were pooled. Outcomes were evaluated at multiple time points up to 1 year. Subgroup analyses were performed based on injection route. Changes were contextualized relative to established minimal clinically important difference (MCID) thresholds. Results: Eighteen RCTs comprising 759 patients were included. In lumbar radiculopathy, saline arms demonstrated statistically significant reductions in leg pain and disability across all evaluated time points. Pooled mean differences for leg pain VAS ranged from −1.79 at 1 month to −3.85 at 1 year, while ODI improvements increased from −7.30 to −17.83 points over the same interval, exceeding MCID thresholds. Improvements were more consistent following epidural injection. By contrast, patients with diskogenic pain exhibited smaller changes in back pain and disability, with most pooled estimates failing to reach MCID thresholds. Conclusions: Saline injection arms of lumbar injection RCTs demonstrate meaningful improvements in pain and disability over time, particularly in patients with lumbar radiculopathy. These findings suggest that saline injections are not inert comparators and may elevate baseline response in interventional trials, potentially obscuring the incremental benefit of active injectates. Future RCTs should consider incorporating nonsaline control arms to better isolate treatment-specific effects and improve interpretability of comparative outcomes. Level of Evidence: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Hollow viscus perforation following spine surgery is uncommon but associated with substantial morbidity and mortality when diagnosis is delayed. Early recognition is challenging because presenting symptoms frequently overlap with expected postoperative bowel dysfunction, and imaging findings may initially be subtle. Despite its clinical significance, the literature remains fragmented across case reports and small series, and a consolidated, mechanism-based framework specific to spine surgery is lacking. We performed a single-institution case series of five patients who developed hollow viscus perforation or significant postoperative intra-abdominal pathology after spine surgery, combined with a comprehensive review of the published literature. Data were analyzed to identify common mechanisms of injury, clinical presentation patterns, diagnostic pathways, management strategies, and preventive considerations. Hollow viscus perforation after spine surgery occurred through four principal mechanisms: direct mechanical injury, functional distension related to acute colonic pseudo-obstruction physiology, delayed hardware or graft migration, and medication-associated ulceration or diverticular perforation. Early clinical findings frequently overlapped with expected postoperative bowel dysfunction, contributing to delayed recognition. Diagnosis depended on identifying deviations from expected recovery trajectories and obtaining timely computed tomography imaging. Preventive strategies included recognition of preoperative abdominal risk factors, meticulous exposure-specific surgical technique, optimization of postoperative bowel function, and judicious use of medications that impair gastrointestinal motility or tissue integrity. Hollow viscus perforation following spine surgery is an uncommon but potentially catastrophic complication arising from distinct mechanical, functional, hardware-related, and medication-associated pathways. Because early signs are often nonspecific, a low threshold for imaging and general surgical evaluation is essential. Improved preoperative risk stratification, intraoperative vigilance, and structured postoperative monitoring may reduce delays in diagnosis and improve outcomes in this high-risk population.

Background/Objectives: Irritable bowel syndrome (IBS) is among the most prevalent disorders of gut–brain interaction, yet its implications for spine surgery remain poorly characterized. This narrative review examines how IBS influences symptom presentation and postoperative outcomes in spine surgery patients. Methods: We synthesized the neurobiologic, epidemiologic, and perioperative literature linking IBS with musculoskeletal pain, spine-related symptomatology, and surgical outcomes, drawing on spine-specific data where available and on related surgical and chronic-pain populations where it was not. Results: IBS is characterized by central sensitization, impaired descending inhibition, increased temporal summation, autonomic dysregulation, and a high prevalence of psychiatric comorbidity, which manifest as widespread hyperalgesia and symptom amplification that overlap with pain mechanisms common in spine surgery patients. Epidemiologic studies indicate that patients with IBS undergo musculoskeletal and spinal procedures at disproportionately high rates, reflecting both symptom burden and diagnostic uncertainty from viscerosomatic overlap. These same factors have been associated with greater postoperative pain, elevated opioid requirements, slower functional recovery, and reduced satisfaction after spine surgery, although direct IBS-specific spine data remain limited. IBS may also confound preoperative assessment by mimicking radicular, discogenic, or sacroiliac pain. Conclusions: IBS represents an under-recognized potential modifier of symptom localization, perioperative pain trajectories, and functional recovery in spine surgery. Greater awareness of IBS-related nociplastic and psychosocial mechanisms may improve preoperative evaluation, risk stratification, perioperative management, and the design of future outcome studies.