Acute lumbar paraspinal compartment syndrome after radical cystectomy.

Lumbar paraspinal compartment syndrome (LPCS) is a rare diagnosis, seen in patients chronically after repeated lumbar trauma or acutely in a postoperative setting. Only a dozen cases are documented worldwide, and to date no clinical guidelines exist for the diagnosis nor the treatment.We describe the case of a 44-year-old man with excruciating lower back pain following a radical cystectomy. The postoperative laboratory values were compatible with acute rhabdomyolysis. The lumbar spine MRI showed necrosis of lumbosacral paraspinal muscles, making the diagnosis of acute LPCS. After seeking advice from different specialists, the conservative approach was chosen with combined pain treatment and physiotherapy. The patient is currently still disabled for some tasks and needs chronic pain medication.

Association patterns between lumbar paraspinal muscles and sagittal malalignment in preoperative patients undergoing lumbar three-column osteotomy.

PURPOSE: We aim to investigate the associations between lumbar paraspinal muscles and sagittal malalignment in patients undergoing lumbar three-column osteotomy. METHODS: Patients undergoing three-column osteotomy between 2016 and 2021 with preoperative lumbar magnetic resonance imaging (MRI) and whole spine radiographs in the standing position were included. Muscle measurements were obtained using a validated custom software for segmentation and muscle evaluation to calculate the functional cross-sectional area (fCSA) and percent fat infiltration (FI) of the m. psoas major (PM) as well as the m. erector spinae (ES) and m. multifidus (MM). Spinopelvic measurements included pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L1-S1 lordosis (LL), T4-12 thoracic kyphosis (TK), spino-sacral angle (SSA), C7-S1 sagittal vertical axis (SVA), T1 pelvic angle (TPA) and PI-LL mismatch (PI - LL). Statistics were performed using multivariable linear regressions adjusted for age, sex, and body mass index (BMI). RESULTS: A total of 77 patients (n = 40 female, median age 64 years, median BMI 27.9 kg/m2) were analyzed. After adjusting for age, sex and BMI, regression analyses demonstrated that a greater fCSA of the ES was significantly associated with greater SS and SSA. Moreover, our results showed a significant correlation between a greater FI of the ES and a greater kyphosis of TK. CONCLUSION: This study included a large patient cohort with sagittal alignment undergoing three-column osteotomy and is the first to demonstrate significant associations between the lumbar paraspinal muscle parameters and global sagittal alignment. Our findings emphasize the importance of the lumbar paraspinal muscles in sagittal malalignment.

Biomechanical Analysis of a Newly Proposed Surgical Combination (MIS Screw-Rod System for Indirect Decompression+ Interspinous Fusion System for long Term Spinal Stability) in Treatment of Lumbar Degenerative Diseases.

OBJECTIVE: The aim of this study is to analyze the biomechanical stability of a newly proposed surgical combination (minimally invasive surgery of screw-rod system for indirect decompression + interspinous fusion system for long term spinal stability) in treatment of lumbar degenerative diseases. METHODS: The three-dimensional (3D) computed tomography (CT) image data of an adult healthy male volunteer were selected. An intact model of L4/5 was further established and validated by using Mimic and 3-matic, 3D slicer, abaqus, Python. Four surgical models were constructed. The biomechanical stability among these surgical modes was compared and analyzed using finite element analysis. RESULTS: The maximum von mises on fixation system in surgical models 2 and 3 exhibited comparable values. This finding suggested that the increase in interspinous fusion did not result in a significant elevation in maximum von mises on fixation system. Compared with the third surgical model, the fourth model, which received less average von mises experienced by the screw in contact with both cancellous and cortical bone. The findings indicated that the inclusion of facet joint fusion in surgical procedures might not be necessary to increase the average von Mises stress experienced by the screw in contact with both cancellous and cortical bone. CONCLUSIONS: The biomechanical stability of the newly proposed surgical combination (MIS screw-rod for indirect decompression + interspinous fusion for long term spinal stability technique) was not lower than that of the other surgical combination groups, and it might not be necessary to perform facet joint fusion during the surgery.

A Proposed Treatment Algorithm for Low Back Pain Secondary to Bertolotti's Syndrome.

BACKGROUND: Chronic low back pain is widely prevalent, and there are a range of conditions that may result in the low back pain. In general, treatment of low back pain starts with conservative management such as medications, physical therapy, and home exercise regimens. If conservative measures fail, a range of interventional techniques can be employed to manage back pain. An uncommonly recognized cause of back pain is Bertolotti's syndrome which is a result of back pain due to lumbosacral transitional vertebrae (LSTV). LSTV is a congenital abnormality either characterized by the lumbarization of the sacrum where the first sacral bone fails to fuse with the rest of the sacrum or the sacralization of the lumbar spine where the L5 vertebra fuses with the sacrum creating a longer sacrum. In many cases, the condition can be recognized by imaging techniques such as an x-ray, computed tomography, or magnetic resonance imaging. OBJECTIVES: To propose a treatment algorithm for patients with low back pain secondary to Bertolotti's syndrome. STUDY DESIGN: Case study and treatment algorithm proposal. METHODS: A treatment algorithm for patients with low back pain secondary to Bertolotti's Syndrome which involves starting with local anesthetic and steroid injection of the pseudo-articulation, followed by radiofrequency ablation of the pseudo-articulation, and then complete endoscopic resection of the pseudo joint. RESULTS: The proposed stepwise treatment guideline has the ability to diagnose Bertolotti's syndrome as the cause of low back pain and provide symptomatic relief. LIMITATIONS: Several limitations exist for the study including the fact that the algorithmic approach may not fit every patient. Additionally, there would be benefit in future research studies comparing each step of the algorithm with conservative measures to compare efficacy and long-term outcomes of the procedures. CONCLUSIONS: Our stepwise approach to diagnosing and managing the pain resulting from Bertolotti's syndrome is an effective method of treatment for the condition.

Comparison of the clinical outcomes of VBE-TLIF versus MIS-TLIF for single-level degenerative lumbar diseases.

OBJECTIVE: This research aims to compare the clinical outcomes of VBE-TLIF and MIS-TLIF for the treatment of patients with single-level degenerative lumbar diseases. METHODS: Ninety patients were enrolled in this study. The estimated blood loss, operation time, postoperative hospitalization days, time to functional exercise, amount of surgical drain and inflammatory index were recorded. The visual analog scale, Oswestry dysfunction index and modified MacNab criteria were used to assessed the patient's back and leg pain, functional status and clinical satisfaction rates. RESULTS: The average operation time of the VBE-TLIF group was longer than that of the MIS-TLIF group. The time for functional exercise, length of hospital stay, estimated blood loss and amount of surgical drain in the VBE-TLIF group were relative shorter than those in the MIS-TLIF group. Additionally, the levels of CRP, neutrophil, IL-6 and CPK in the VBE-TLIF group were significantly lower than those in the MIS-TLIF group at postoperative days 1 and 3, respectively (P < 0.001). Patients undergoing VBE-TLIF had significantly lower back VAS scores than those in the MIS-TLIF group on postoperative days 1 and 3 (P < 0.001). No significant differences were found in the clinical satisfaction rates (95.83 vs. 95.24%, P = 0.458) or interbody fusion rate (97.92 vs. 95.24%, P = 0.730) between these two surgical procedures. CONCLUSIONS: Both VBE-TLIF and MIS-TLIF are safe and effective surgical procedures for patients with lumbar diseases, but VBE-TLIF technique is a preferred surgical procedure with merits of reduced surgical trauma and quicker recovery.

How I do it: dual operation channels percutaneous endoscopic far-lateral transforaminal lumbar interbody fusion.

BACKGROUND: The current surgical procedure of interbody fusion in the lumbar spine has several limitations including low efficiency, potential endplate damage, overdose radiation exposure, and failure of fusion. METHODS: Through the endoscopic operating channel, we efficiently removed the superior and inferior articular processes and decompressed the ligamentum flavum. Another operating channel was established under endoscopic monitoring to excise the annulus fibrosus, remove the cartilaginous endplate using open instruments, perform interbody bone grafting, and place a non-expandable polyetheretherketone open surgical fusion cage. CONCLUSION: Lumbar interbody fusion was performed successfully using a far-lateral transforaminal approach combined with dual operation channels of percutaneous endoscopic-assisted technique.

Influences of lumbo-sacral transitional vertebrae for anterior lumbar interbody fusion.

Lumbo-sacral transitional vertebrae (LSTV) are frequent congenital variances of the spine and are associated with increased spinal degeneration. Nevertheless, there is a lack of data whether bony alterations associated with LSTV result in reduced segmental restoration of lordosis when performing ALIF. 58 patients with monosegmental stand-alone ALIF in the spinal segment between the 24th and 25th vertebra (L5/S1)/(L5/L6) where included. Of these, 17 patients had LSTV and were matched to a control population by age and sex. Pelvic incidence, pelvic tilt, sagittal vertical axis, lumbar lordosis, segmental lordosis, disc height and depth were compared. LSTV-patients had a significantly reduced segmental lordosis L4/5 (p = 0.028) and L5/S1/(L5/L6) (p = 0.041) preoperatively. ALIF resulted in a significant increase in segmental lordosis L5/S1 (p < 0.001). Postoperatively, the preoperatively reduced segmental lordosis was no longer significantly different in segments L4/5 (p = 0.349) and L5/S1/(L5/6) (p = 0.576). ALIF is associated with a significant increase in segmental lordosis in the treated segment even in patients with LSTV. Therefore, ALIF is a sufficient intervention for restoring the segmental lordosis in these patients as well.

Effect of Lateral Surgery Compared with Posterior Surgery on Lumbar Degenerative Disease: A Meta-Analysis of 41 Cohort Studies.

OBJECTIVE: The purpose of this study was to compare the efficacy of the lateral approach and posterior approach in the treatment of lumbar degenerative diseases. METHODS: Through a systematic search of relevant articles published on or before July 20, 2023, in the Embase, PubMed, and Cochrane libraries, the 2 authors independently extracted data and used the Newcastle‒Ottawa scale to evaluate the quality of the included studies. Using Stata16 software, the continuous variables were presented as the standard mean deviation, and the bipartite variables were analyzed using the pooled odds ratio with 95% confidence interval. RESULTS: A total of 13,892 articles were screened and 10,908 studies were identified after deleting duplicates, of which 41 met the criteria and were included in the meta-analysis. The meta-analysis showed that the lateral approach was superior to the posterior approach in reducing blood loss, operation time, and hospital stay. At the same time, compared with the posterior approach, the lateral approach has more advantages in the long-term Japanese Orthopaedic Association score and Oswestry Disability Index score, adjusting mid- and long-term LL and short- and long-term disc height. CONCLUSIONS: Lateral and posterior surgery have similar clinical effects in the treatment of lumbar degenerative diseases and can significantly reduce pain and improve postoperative SL. At the same time, the lateral approach has more advantages in improving long-term quality of life, reducing the long-term disability index, adjusting mid- and long-term LL and short- and long-term disc height.

Complex lumbosacral spinal cord lipomas: A longitudinal study on outcomes from a Singapore children's hospital.

BACKGROUND: Total/near-total resection (TR/NTR) of complex lumbosacral lipomas (CSL) is reported to be associated with better long-term functional outcomes and lower symptomatic re-tethering rates. We report our institutional experience for CSL resection in affected children. METHODS: This is a single-institution, retrospective study. Inclusion criteria consist of patients with CSL with dorsal, transitional and chaotic lipomas based on Pang et al's classification. The study population is divided into 2 groups: asymptomatic patients with a normal preoperative workup referred to as 'prophylactic intent' and 'therapeutic intent' for those with pre-existing neuro-urological symptoms. Primary aims are to review factors that affect post-operative clean intermittent catheterization (CIC), functional outcomes based on Necker functional score (NFS), and re-tethering rates. RESULTS: 122 patients were included from 2000 to 2021. There were 32 dorsal lipomas (26.2 %), 74 transitional lipomas (60.7 %), and 16 chaotic lipomas (13.1 %). 82 % patients achieved TR/NTR. Favourable NFS at 1-year was 48.2 %. The re-tethering rate was 6.6 %. After multivariable analysis, post-operative CIC was associated with median age at surgery (p = 0.026), lipoma type (p = 0.029), conus height (p = 0.048) and prophylactic intent (p < 0.001). Next, extent of lipoma resection (p = 0.012) and the post-operative CSF leak (p = 0.004) were associated with re-tethering. Favourable NFS was associated with lipoma type (p = 0.047) and prophylactic intent surgery (p < 0.001). CONCLUSIONS: Our experience shows that TR/NTR for CSL is a feasible option to prevent functional deterioration and re-tethering. Efforts are needed to work on factors associated with post-operative CIC.

Clinical role of crosslink augmentation during short-segment posterior lumbar interbody fusion with total facetectomy: A propensity score-matched analysis.

We investigated the clinical role of crosslink augmentation during PLIF with total facetectomy. We retrospectively reviewed 376 patients who underwent one- or two-segment PLIF with unilateral or bilateral total facetectomy between January 2017 and March 2022. The patients were categorized into two groups based on whether a crosslink was instrumented or not. Radiological outcome measurements included fusion status and implant failure rates on 12-month postoperative computed tomography. Patient-reported outcome measures included the Numerical Rating Scale for lower back pain, Oswestry Disability Index, and Short Form-12 Physical Component Summary scores, which were assessed preoperatively and at 12 months postoperatively. Surgery-related complications included surgical site infection, symptomatic implant failure, and epidural hematoma. Propensity score matching was performed to compare both groups after adjusting for confounding factors, including baseline and surgical procedural characteristics. A total of 200 cases were included in the propensity score calculation, and one-to-one matching was performed, resulting in 56 pairs with and without a crosslink. The fusion status (88.7 % vs. 85.5 %), screw loosening (14.3 % vs. 14.3 %), cage subsidence (17.9 % vs. 16.1 %), and cage dislodgement (5.4 % vs. 0 %) showed no significant difference between those with and without a crosslink, respectively. No significant differences were observed in the patient-reported outcomes or surgery-related complication rates between the groups. Crosslink augmentation during PLIF with total facetectomy is not recommended because it does not provide any radiological or clinical benefit and is associated with avoidable expenses.

Analysis of the Frequency of Intraoperative Complications in Anterior Lumbar Interbody Fusion: A Systematic Review.

OBJECTIVE: We assessed the frequency of intraoperative complication rates related to access surgery, operating time, and intraoperative bleeding rates described in the literature for patients undergoing anterior lumbar interbody fusion (ALIF) to evaluate the adverse effects and, thus, help in therapeutic decision making and contribute to future clinical trials. METHODS: A systematic review was conducted of MEDLINE and Embase databases in March 2023. The main inclusion criteria were adult patients aged >18 years, with no maximum age limit; the use of ALIF; the presence of quantitative data on intraoperative complications; and randomized controlled trials and cohort studies. Vascular and peritoneal injuries were considered primary endpoints. The operative time and intraoperative bleeding rate were secondary endpoints. Reports and case series, case-control series, systematic reviews, and meta-analyses were excluded. RESULTS: Eight studies were included with a total of 2395 patients. We found important quantitative data for future randomized clinical studies involving ALIF surgery, including the rate of vascular lesions (2.79%) and peritoneal lesions (0.37%). In addition to these factors, only 4 of the 8 studies addressed the average surgery time, with a total average of 145.61 minutes. Furthermore, 6 of the 8 articles reported the mean rate of intraoperative bleeding, with a total mean blood loss of 272.75 mL. CONCLUSIONS: ALIF is a lumbar spine access technique with low intraoperative complications. Patients with contraindications have a higher risk of complications. Randomized clinical trials are needed to assess the efficacy and safety of the procedure.

The use of lateral lumbar interbody fusion for identifying adult patients with spinal deformities treatable by short corrective fusion in 2-stage surgery.

BACKGROUND: To investigate and compare the surgical outcomes of short and thoracopelvic corrective fusion with our two-stage technique using lateral lumbar interbody fusion (LLIF) and posterior open surgery. METHODS: Consecutive patients with adult spinal deformities who underwent a planned two-stage anterior-posterior surgery, using LLIF for the first stage and posterior open corrective fusion for the second stage, with a minimum of 2 years of follow-up were included. Patients who underwent lumbar or lumbosacral corrective fusion and thoracopelvic corrective fusion were categorized into the short group and thoracopelvic groups, respectively. We investigated the spinopelvic parameters and patient-reported outcome measurements. RESULTS: Seventy-four consecutive patients (8 men, 66 women; average age, 70.0 years) were included. Ten patients underwent short corrective fusion following significant improvements in the symptoms and radiographic parameters post-LLIF. Several preoperative spinopelvic parameters were better in the short group. Compared to the thoracopelvic group, those who underwent short fusion had a poorer alignment 2 years postoperatively but with comparable results and a significantly higher function score on the Scoliosis Research Society-22 r (SRS-22r) questionnaire. The mean Oswestry Disability Index and SRS-22r scores significantly improved during the 2-year postoperative follow-up in both the groups. CONCLUSIONS: Short corrective fusion can be considered in patients whose symptoms and radiographic parameters significantly improve following LLIF. Patients who undergo short fusion with LLIF application have poorer alignment than those who undergo thoracopelvic fusion 2 years postoperatively; however, the results are comparable, and the function score is significantly improved.

Biomechanical evaluation of Percutaneous endoscopic posterior lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion: a biomechanical analysis.

In order to analyze and evaluate the stability of lumbar spine and the risk of cage subsidence after different minimally invasive fusion operations, two finite element models Percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) and minimally invasive transforaminal lumbar interbody Fusion (MIS-TLIF) were established. The results showed that compared with MIS-TLIF, PE-PLIF had better segmental stability, lower pedicle screw rod system stress, and lower risk of cage subsidence. The results suggest that the cage with appropriate height should be selected to ensure the segmental stability and avoid the risk of the subsidence caused by the cage with large height.

Assessment of the External Validity of Dialogue Support for Predicting Lumbar Spine Surgery Outcomes in a US Cohort.

STUDY DESIGN: External validation using prospectively collected data. OBJECTIVES: To determine the model performance of "Dialogue Support" (DS) in predicting outcomes after lumbar spine surgery. SUMMARY OF BACKGROUND DATA: To help clinicians discuss risk versus benefit with patients considering lumbar fusion surgery, DS has been made available online. As DS was created using a Swedish sample, there is a need to study how well DS performs in alternative populations. PATIENTS AND METHODS: Preoperative data from patients enrolled in the Quality Outcomes Database were entered into DS. The probability for each patient to report satisfaction, achieve success (leg pain improvement ≥3), or have no leg pain 12 months after surgery was extracted and compared with their actual 12-month postoperative data. The ability of DS to identify patients in the Quality Outcomes Database who report satisfaction, achieve success, or have no leg pain 12 months after surgery was determined using Receiver operating characteristic curve analysis, goodness-of-fit tests, and calibration plots. RESULTS: There was a significant improvement in all outcomes in 23,928 cases included in the analysis from baseline to 12 months postoperative. Most (84%) reported satisfaction, 67% achieved success, and 44% were pain-free 12 months postoperative. Receiver operating characteristic analysis showed that DS had a low ability to predict satisfaction [area under the curve (AUC) = 0.606], success (AUC = 0.546), and being pain-free (AUC = 0.578) at 12 months postoperative; poor fit for satisfaction (<0.001) and being pain-free ( P = 0.004), but acceptable fit for success ( P = 0.052). Calibration plots showed underestimation for satisfaction and success, but acceptable estimates for being pain-free. CONCLUSION: DS is not directly transferable to predict satisfaction and success after lumbar surgery in a US population. This may be due to differences in patient characteristics, weights of the variables included, or the exclusion of unknown variables associated with outcomes. Future studies to better understand and improve the transferability of these models are needed.

Subfascial Lumbar Spine Drain Output Does Not Affect Outcomes After Incidental Durotomies in Elective Spine Surgery.

OBJECTIVE: Postoperative drains have long been regarded as a preventive measure to mitigate the risks of complications such as neurological impairment by reducing fluid accumulation following spine surgery. Our study aims to contribute to the existing body of knowledge by examining the effects of postoperative drain output on the 90-day postoperative outcomes for patients who experienced an incidental durotomy after lumbar decompression procedures, with or without fusion. METHODS: All patients aged ≥18 years with an incidental durotomy from spinal decompression with or without fusion surgery between 2017 and 2021 were retrospectively identified. The patient demographics, surgical characteristics, method of dural tear repair (DuraSeal, suture, and/or DuraGen), surgical outcomes, and drain data were collected via medical record review. Patients were grouped by readmission status and final 8-hour drain output. Those with a final 8-hour drain output of ≥40 mL were included in the high drain output (HDO) group and those with <40 mL were in the low drain output (LDO) group. RESULTS: There were no statistically significant differences in preoperative patient demographics, surgical characteristics, method of dural tear repair, length of stay (HDO, 4.02 ± 1.90 days; vs. LDO, 4.26 ± 2.10 days; P = 0.269), hospital readmissions (HDO, 10.6%; vs. LDO, 7.96%; P = 0.744), or occurrence of reoperation during readmission (HDO, 6.06%; vs. LDO, 2.65%; P = 0.5944) between the 2 groups. CONCLUSIONS: For patients undergoing primary lumbar decompression with or without fusion and experiencing an incidental durotomy, no significant association was found between the drain output and 90-day patient outcomes. Adequate fascial closure and the absence of symptoms may be satisfactory criteria for standard patient discharge regardless of drain output.

Preoperative interactive virtual simulation applying three-dimensional multifusion images using a haptic device for lumbosacral lipoma.

PURPOSE: Untethering surgery for lumbosacral lipoma is a preventive procedure, and avoidance of complications and good long-term outcomes are required. We introduced presurgical interactive virtual simulation (IVS) applying three-dimensional multifusion images using a haptic device aimed at improving operative outcomes. METHODS: Fourteen patients with newly diagnosed lumbosacral lipoma were recruited and underwent preoperative IVS. The median age at surgery was 8 months. A three-dimensional image analysis system was used to extract and fuse structures necessary for surgery, such as the lipoma, spinal cord and skin, from CT and MRI, and create three-dimensional multifusion images. The created images were individually converted to standard triangulated language format and loaded onto a workstation (Geomagic freeform™) that could be freely transformed, and the laminectomy range and lipoma extraction procedure were examined. Presurgical IVS was performed, and the actual surgery was performed. RESULTS: The disease types were dorsal, caudal, lipomyelomeningocele, transitional, and filum in 5, 5, 2, 1, and 1 patients, respectively. The surgical procedure and extent of the laminectomy were as planned for all patients. Resection of the lipomas tended to be less than expected preoperatively because of positive reactions on intraoperative monitoring. No postoperative complications were observed. The median postoperative follow-up period was 29 months, and there were no reoperations during the observation period. CONCLUSIONS: Although there are various types of lumbosacral lipoma, surgery can be safely performed by performing presurgical IVS. The short-term course is good; however, long-term follow-up is necessary for the appearance of neurological symptoms associated with growth and re-tethering.

Thoracic and Lumbar Spine Injury: Evidence-Based Diagnosis, Management, and Outcomes.

BACKGROUND: Traumatic thoracolumbar spine injuries are associated with significant morbidity and mortality. Targeted for non-spine specialist trauma surgeons, this systematic scoping review aimed to examine literature for up-to-date evidence on presentation, management, and outcomes of thoracolumbar spine injuries in adult trauma patients. METHODS: This review was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. We searched four bibliographic databases: PubMed, EMBASE, Web of Science, and the Cochrane Library. Eligible studies included experimental, observational, and evidence-synthesis articles evaluating patients with thoracic, lumbar, or thoracolumbar spine injury, published in English between January 1, 2010 and January 31, 2021. Studies which focused on animals, cadavers, cohorts with N <30, and pediatric cohorts (age <18 years old), as well as case studies, abstracts, and commentaries were excluded. RESULTS: A total of 2501 studies were screened, of which 326 unique studies were fully text reviewed and twelve aspects of injury management were identified and discussed: injury patterns, determination of injury status and imaging options, considerations in management, and patient quality of life. We found: (1) imaging is a necessary diagnostic tool, (2) no consensus exists for preferred injury characterization scoring systems, (3) operative management should be considered for unstable fractures, decompression, and deformity, and (4) certain patients experience significant burden following injury. DISCUSSION: In this systematic scoping review, we present the most up-to-date information regarding the management of traumatic thoracolumbar spine injuries. This allows non-specialist trauma surgeons to become more familiar with thoracolumbar spine injuries in trauma patients and provides a framework for their management.

Primary anterior lumbar interbody fusion, with and without posterior instrumentation: a 1,377-patient cohort from a multicenter spine registry.

BACKGROUND CONTEXT: Lumbar interbody instrumentation techniques are common and effective surgical options for a variety of lumbar degenerative pathologies. Anterior lumbar interbody fusion (ALIF) has become a versatile and powerful means of decompression, stabilization, and reconstruction. As an anterior only technique, the integrity of the posterior muscle and ligaments remain intact. Adding posterior instrumentation to ALIF is common and may confer benefits in terms of higher fusion rate but could contribute to adjacent segment degeneration due to additional rigidity. Large clinical studies comparing stand-alone ALIF with and without posterior supplementary fixation (ALIF+PSF) are lacking. PURPOSE: To compare rates of operative nonunion and adjacent segment disease (ASD) in ALIF with or without posterior instrumentation. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Adult patients (≥18 years old) who underwent primary ALIF for lumbar degenerative pathology between levels L4 to S1 over a 12-year period. Exclusion criteria included trauma, cancer, infection, supplemental decompression, noncontiguous fusions, prior lumbar fusions, and other interbody devices. OUTCOME MEASURES: Reoperation for nonunion and ASD compared between ALIF only and ALIF+PSF. METHODS: Reoperations were modeled as time-to-events where the follow-up time was defined as the difference between the primary ALIF procedure and the date of the outcome of interest. Crude cumulative reoperation probabilities were reported at 5-years follow-up. Multivariable Cox proportional hazard regression was used to evaluate risk of operative nonunion and for ASD adjusting for patient characteristics. RESULTS: The study consisted of 1,377 cases; 307 ALIF only and 1070 ALIF+PSF. Mean follow-up time was 5.6 years. The 5-year crude nonunion incidence was 2.4% for ALIF only and 0.5% for ALIF+PSF; after adjustment for covariates, a lower operative nonunion risk was observed for ALIF+PSF (HR=0.22, 95% CI=0.06-0.76). Of the patients who are deemed potentially suitable for ALIF alone, one would need to add posterior instrumentation in 53 patients to prevent one case of operative nonunion at a 5-year follow-up (number needed to treat). Five-year operative ASD incidence was 4.3% for ALIF only and 6.2% for ALIF+PSF; with adjustments, no difference was observed between the cohorts (HR=0.96, 95% CI=0.54-1.71). CONCLUSIONS: While the addition of posterior instrumentation in ALIFs is associated with lower risk of operative nonunion compared with ALIF alone, operative nonunion is rare in both techniques (<5%). Accordingly, surgeons should evaluate the added risks associated with the addition of posterior instrumentation and reserve the supplemental posterior fixation for patients that might be at higher risk for operative nonunion. Rates of operative ASD were not statistically higher with the addition of posterior instrumentation suggesting concern regarding future risk of ASD perhaps should not play a role in considering supplemental posterior instrumentation in ALIF.