Anterior Lumbar Interbody Fusion Research Articles

466 Primary Anterior Lumbar Interbody Fusion, With and Without Posterior Instrumentation: A 1377 Patient Cohort From a Multicenter Spine Registry

INTRODUCTION: Anterior lumbar interbody fusion (ALIF) is a versatile and powerful technique for a variety of lumbar degenerative pathologies. Adding posterior supplementary fixation to ALIF (ALIF+PSF) is common and may confer benefits in terms of higher fusion rate but could contribute to adjacent segment disease (ASD) due to additional rigidity. METHODS: Adult patients who underwent primary ALIF for lumbar degenerative pathology between levels L4-S1 over a 12-year period were included. Cases of trauma, cancer, infection, supplemental decompression, noncontiguous fusions, prior lumbar fusions, and other interbody devices were excluded. Primary outcomes included reoperation for nonunion and ASD. Multivariable Cox proportional hazard regression was used to evaluate risks adjusting for patient characteristics. RESULTS: The study consisted of 1377 cases; 307 ALIF alone and 1070 ALIF+PSF. Mean follow-up time was 5.6-years. 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 = 0.07-0.70). Of patients deemed potentially suitable for ALIF alone, one would need to add PSF 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 = 0.53-1.74). CONCLUSIONS: While addition of posterior instrumentation in ALIFs is associated with lower risk of operative nonunion compared to ALIF alone, it is rare in both techniques (<5%). Accordingly, surgeons should evaluate added risks associated with addition of PSF, and rather reserve PSF for patients at higher risk for operative nonunion. Rates of operative ASD were not statistically higher with addition of PSF suggesting concern regarding future ASD may be less supported.

Risk factors for vascular injuries in anterior lumbar interbody fusion: a single-institution retrospective study.

Vascular injuries in anterior lumbar interbody fusion (ALIF) occur due to the vascular manipulation needed to achieve optimal disc space exposure. In this study, the authors aimed to evaluate intraoperative vascular injuries in patients undergoing single- and multilevel ALIF at a large tertiary academic center. Prospectively collected data specifically addressing postoperative complications in patients who underwent ALIF by neurosurgery spine faculty working with a specialized vascular surgeon were retrospectively reviewed. Demographic characteristics and intraoperative data were collected. Patients were split into vascular injury and non-vascular injury groups. Outcome comparisons were conducted using the chi-square exact and Wilcoxon rank-sum tests for categorical and continuous data, respectively. Logistic regression was used to investigate associations with vascular injury, with univariate analysis first conducted to identify candidate associations. Based on these results, variables demonstrating a between-groups test statistic of p < 0.10 were included in the multivariate analysis to determine the independent predictors of vascular injuries. In total, 323 patients who underwent ALIF procedures were identified: 51% were male (n = 166) and 49% were female (n = 157). The mean age was 57.1 years, with 56% (n = 182) having undergone prior lumbar surgery. Vascular injuries were encountered intraoperatively in 7.1% (n = 23) of patients, and the majority (91% [n = 21]) involved the left common iliac vein. Patients with vascular injuries were statistically older (mean 63.6 vs 56.6 years), had greater incidence rates of coronary artery disease, opioid use, multilevel ALIF surgery involving the L2-3 level, and surgery involving multiple disc spaces, had more multilevel anterior instrumentation, and experienced greater blood loss during surgery and longer length of stay (all p < 0.05). Overall, there was 1 death (0.3%) secondary to aortic artery injury. Multivariate analysis identified opioid use, multilevel ALIF involving L2-3, and multiple interbodies as statistically independent predictors of vascular injury (all p < 0.05). Identifying patient risk factors can reduce the risk of vascular injuries in ALIF. Opioid use, multilevel ALIF involving L2-3, and multiple interbodies were independent predictors of vascular injuries in ALIF.

Novel Approach to Difficult Spinal Reconstruction: Bilateral Simultaneous Rib and Iliac Crest Vascularized Bone Graft Spinoplastic Surgery

Summary: Pseudoarthrosis is a severe complication of spinal fusion surgery with occurrence rates as high as 35%–40%. Current options of revision surgery to correct pseudoarthrosis frequently carry high failure rates and risk of developing junctional kyphosis. Pedicled vascularized bone grafts (VBGs) are an innovative approach to boost spinal fusion rates via improving structural integrity and increasing the delivery of blood to the donor site. This versatile technique can be performed at different spinal levels without additional skin incisions and with minimal added operative time. Here we present the first bilateral rib and iliac crest VBG spinoplastic surgery performed to augment spinal fusion in a 68-year-old woman with distal junctional kyphosis and severe positive sagittal balance with low back and neck pain and significant difficulty standing upright. The patient had history of multiple spinal operations with preoperative CT imaging demonstrating loosening and pull out of L3 and fracture of L2 screws. She underwent two-stage surgical treatment involving anterior lumbar interbody fusion L3-S1 followed by removal of hardware, T4 to pelvis fusion with L2-3 prone lateral interbody fusion, and T11-S1 posterior column osteotomies. The surgery was augmented by bilateral rib and iliac crest VBGs performed by plastic surgery. At three-month follow-up the patient demonstrated functional improvement, being able to maintain upright posture and walk; was satisfied with the result of the surgery; and demonstrated no graft-related complications. In conclusion, utilization of pedicled VBGs is a novel, promising approach to augment spinal surgery in high risk patients.

The influence of preoperative Veterans RAND-12 physical composite score in patients undergoing anterior lumbar interbody fusion [Retrospective Review]

No study has evaluated the preoperative impact of Veterans RAND-12 Physical Composite Score (VR-12 PCS) on anterior lumbar interbody fusion (ALIF) patients. This study examines its influence on physical function, mental health, pain, and disability outcomes. Two cohorts of ALIF patients with preoperative VR-12 PCS scores were formed using a single-surgeon registry: VR-12 PCS < 30 and VR-12 PCS ≥ 30. Demographics, perioperative characteristics, and patient-reported outcome measures (PROMs) were collected. PROMs of VR-12 PCS/Mental Composite Score (MCS), Short Form-12 (SF-12) PCS/MCS, Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale-Back/Leg Pain (VAS-BP/LP), and Oswestry Disability Index (ODI) were collected pre/postoperatively up to 2-years. Demographics, perioperative characteristics, and preoperative PROMs were compared. Intercohort postoperative 6-week/final PROMs and improvements were compared. Of 80 patients, there were 41 in the VR-12 PCS < 30 cohort. Besides VR-12 PCS, VR-12 PCS < 30 patients reported inferior preoperative VR-12 MCS/SF-12 PCS/PROMIS-PF/PHQ-9/ODI scores (p ≤ 0.003, all). At 6-weeks postoperatively, VR-12 PCS < 30 reported inferior VR-12 PCS/SF-12 PCS/PROMIS-PF/PHQ-9 (p ≤ 0.030, all). There was greater improvement up to 6-weeks postoperatively in VR-12 PCS < 30 for VR-12 PCS/MCS and SF-12 PCS (p ≤ 0.020, all). VR-12 PCS < 30 reported superior improvement by final follow-up in VR-12 PCS/SF-12 PCS/PHQ-9 (p ≤ 0.006, all). MCID achievement rates were higher in VR-12 PCS < 30 for PHQ-9 and ODI (p ≤ 0.013, both). VR-12 PCS < 30 patients reported inferior postoperative physical function, mental health, and disability, yet superior magnitude of improvement in physical function and mental health. Rates of clinically meaningful improvement for VR-12 PCS < 30 were greater in mental health and disability.

Retrospective analysis of medium-term outcomes following anterior lumbar interbody fusion surgery performed in a tertiary spinal surgical centre.

Anterior lumbar interbody fusion (ALIF) can treat spondylolisthesis, degenerative disc disease and pseudoarthrosis. This approach facilitates complete discectomy, disc space distraction, indirect decompression of neural foramina and placement of large interbody devices. Several intra- and postoperative complications can be attributed to the anterior approach: vascular/visceral injury, hypogastric plexus injury and urogenital consequences. Spine-specific complications include implant migration, graft failure, pseudoarthrosis and persistent symptomology. This retrospective study reviewed patient demographics, medium-term outcomes and complication rates following ALIF surgery performed over a 5-year period. A total of 110 consecutive patients had undergone ALIF surgery at a single tertiary spinal centre. The database was reviewed with a primary outcome of identifying postoperative 90-day complications and whether a revision anterior operation was required after primary ALIF. No patients required revision anterior operation after their primary ALIF surgery by final follow-up. Out of 110 patients, 11 (10%) recorded a complication attributed to the anterior stage of their operation within 90 days. Our 90-day complication rate of 10% lies within the 2.6% acute complication and 40% overall complications rates described in previous literature. The risk of vascular/visceral injury is significant (3%) and we recommend that ALIF be performed as a dual surgeon procedure with a vascular-trained access surgeon accompanying the spinal surgeon. ALIF is a valid revision surgical option for failed posterior approaches leading to complications such as pseudoarthrosis. In our sample, 89% of patients were managed with posterior fixation to augment the anterior fusion as, biomechanically, this is a proven construct.

Is the Use of Intraoperative Neuromonitoring Justified During Lumbar Anterior Approach Surgery?

Intraoperative neuromonitoring (IONM) became widely used in spine surgery to reduce the risk of iatrogenic nerve injury. However, the proliferation of IONM has fallen into question based on effectiveness and costs, with a lack of evidence supporting its benefit for specific spine surgery procedures. The purpose of this study was to evaluate the use of IONM and the rate of neurological injury associated with anterior lumbar spinal surgery. This was a retrospective study on a consecutive series of 359 patients undergoing lumbar anterior approach surgery for anterior lumbar interbody fusion (ALIF), total disc replacement (TDR), or hybrid (ALIF with TDR) for the treatment of symptomatic disc degeneration. Patients undergoing any posterior spine surgery were excluded. Operative notes were reviewed to identify any changes in IONM and the surgeon's response. Clinic notes were reviewed up to 3 months postoperatively for indications of iatrogenic nerve injury. There were 3 aberrant results with respect to IONM. Changes in IONM of a lower extremity occurred for 1 patient (0.3%). The surgeon evaluated the situation and there was no observable reason for the IONM change. Upon waking, the patient was found to have no neurological deficit. There were 2 cases of neurologic deficits in this population, which were classified as false-negatives of IONM (0.56%, 95% CI: 0.1% to 1.8%). In both cases, the patients were found to have a foot drop after the anterior approach surgery. In this study, there was 1 false-positive and 2 false-negative results of IONM. These data suggest that IONM is not beneficial in this population. However, many surgeons may feel obligated to use IONM for medicolegal reasons. There is a need for future studies to delineate cases in which IONM is beneficial and the type of monitoring to use, if any, for specific spine surgery types. This study questions the routine use of IONM in anterior lumbar approach surgery for the treatment of symptomatic disc degeneration. This has significant implications related to the cost of this practice.

Oblique anterior column realignment with a mini-open posterior column osteotomy for minimally invasive adult spinal deformity correction: illustrative case.

Adult spinal deformity (ASD) occurs from progressive anterior column collapse due to disc space desiccation, compression fractures, and autofusion across disc spaces. Anterior column realignment (ACR) is increasingly recognized as a powerful tool to address ASD by progressively lengthening the anterior column through the release of the anterior longitudinal ligament during lateral interbody approaches. Here, we describe the application of minimally invasive ACR through an oblique antepsoas corridor for deformity correction in a patient with adult degenerative scoliosis and significant sagittal imbalance. A 65-year-old female with a prior history of L4-5 transforaminal lumbar interbody fusion and morbid obesity presented with refractory, severe low-back and lower-extremity pain. Preoperative radiographs showed significant sagittal imbalance. Computed tomography showed a healed L4-5 fusion and a vacuum disc at L3-4 and L5-S1, whereas magnetic resonance imaging was notable for central canal stenosis at L3-4. The patient was treated with a first-stage L5-S1 lateral anterior lumbar interbody fusion with oblique L2-4 ACR. The second-stage posterior approach consisted of a robot-guided minimally invasive T10-ilium posterior instrumented fusion with a mini-open L2-4 posterior column osteotomy (PCO). Postoperative radiographs showed the restoration of her sagittal balance. There were no complications. Oblique ACR is a powerful minimally invasive tool for sagittal plane correction. When combined with a mini-open PCO, substantial segmental lordosis can be achieved while eliminating the need for multilevel PCO or invasive three-column osteotomies.

Frailty predicts non-home discharge in anterior lumbar interbody fusion patients.

Anterior lumbar interbody fusion (ALIF) is a well-established surgical approach in the treatment of degenerative pathology, trauma, infection, and neoplasia of the spine. This study sought to assess the usefulness of frailty as a predictor of non-home discharge (NHD) for patients who undergo the procedure. Patient cases were extracted from the American College of Surgeons's National Surgical Quality Improvement Program database from 2012 to 2020. Univariable and receiver operating characteristic curve analyses were used to compare the 5-item Modified Frailty Index (mFI-5) to the Revised Risk Analysis Index (RAI-rev) in relation to NHD. Simple linear regression demonstrated that increasing frailty was associated with an increased likelihood of NHD among 25,317 patients (mFI-5 odds ratio: 2.13, 3.23, 8.4; RAI-rev odds ratio: 3.22, 9.6, 23.6 [P<0.001 for all]). In each instance, a Cochran-Armitage trend test was significant (P<0.001), indicating a linear association of increasing odds. The RAI-rev resulted in a C-statistic of 0.722, compared to 0.628 for the mFI-5, and was shown to have superior discriminative ability with a DeLong Test (P<0.001). Frailty, as measured by mFI-5 and RAI-rev, was associated with an increased likelihood of NHD in patients who underwent ALIF. This finding supports recent literature on the promising utility of these indices, especially the RAI-rev, in preoperative decision-making across multiple facets of neurosurgery.

Are there differences in the reoperation rates for operative adjacent-segment disease between ALIF+PS, PLIF+PS, TLIF+PS, and LLIF+PS? An analysis of a cohort of 5291 patients.

Biomechanical factors in lumbar fusions accelerate the development of adjacent-segment disease (ASD). Stiffness in the fused segment increases motion in the adjacent levels, resulting in ASD. The objective of this study was to determine if there are differences in the reoperation rates for symptomatic ASD (operative ASD) between anterior lumbar interbody fusion plus pedicle screws (ALIF+PS), posterior lumbar interbody fusion plus pedicle screws (PLIF+PS), transforaminal lumbar interbody fusion plus pedicle screws (TLIF+PS), and lateral lumbar interbody fusion plus pedicle screws (LLIF+PS). A retrospective study using data from the Kaiser Permanente Spine Registry identified an adult cohort (≥ 18 years old) with degenerative disc disease who underwent primary lumbar interbody fusions with pedicle screws between L3 to S1. Demographic and operative data were obtained from the registry, and chart review was used to document operative ASD. Patients were followed until operative ASD, membership termination, the end of study (March 31, 2022), or death. Operative ASD was analyzed using Cox proportional hazards models. The final study population included 5291 patients with a mean ± SD age of 60.1 ± 12.1 years and a follow-up of 6.3 ± 3.8 years. There was a total of 443 operative ASD cases, with an overall incidence rate of reoperation for ASD of 8.37% (95% CI 7.6-9.2). The crude incidence of operative ASD at 5 years was the lowest in the ALIF+PS cohort (7.7%, 95% CI 6.3-9.4). In the adjusted models, the authors failed to detect a statistical difference in operative ASD between ALIF+PS (reference) versus PLIF+PS (HR 1.06 [0.79-1.44], p = 0.69) versus TLIF+PS (HR 1.03 [0.81-1.31], p = 0.83) versus LLIF+PS (HR 1.38 [0.77-2.46], p = 0.28). In a large cohort of over 5000 patients with an average follow-up of > 6 years, the authors found no differences in the reoperation rates for symptomatic ASD (operative ASD) between ALIF+PS and PLIF+PS, TLIF+PS, or LLIF+PS.

Comparison of multilevel low-grade techniques versus three-column osteotomies in adult spinal deformity surgery: does harmonious correction matter?

Recent debate has arisen between whether to use a three-column osteotomy (3CO) or multilevel low-grade (MLG) techniques to treat severe sagittal malalignment in adult spinal deformity (ASD) surgery. The goal of this study was to compare the outcomes of 3CO and MLG techniques performed in corrective surgeries for ASD. ASD patients who had a baseline PI-LL > 30° and 2-year follow-up data were included. Patients underwent either 3CO or MLG (thoracolumbar posterior column osteotomies at ≥ 3 levels or anterior lumbar interbody fusion at ≥ 3 levels with no 3CO). The segmental utility ratio was used to assess relative segmental correction (segmental correction divided by overall correction in lordosis divided by the number of thoracolumbar interventions [interbody fusion, thoracolumbar posterior column osteotomies, and 3CO]). The paired t-test was used to assess lordotic distribution by differences in lordosis between adjacent lumbar disc spaces (e.g., L1-2 to L2-3). Multivariate analysis, controlling for age, sex, BMI, osteoporosis, baseline pelvic incidence, and T1 pelvic angle, was used to evaluate the complication rates and radiographic and patient-reported outcomes between the groups. A total of 93 patients were included, 53% of whom underwent MLG and 47% of whom underwent 3CO. The MLG group had a lower BMI (p < 0.05). MLG patients received fewer previous fusions than 3CO patients (31% vs 80%, p < 0.001). MLG patients had 24% less blood loss but a 22% longer operative time (565 vs 419 minutes, p = 0.008). Using adjusted analysis, the 3CO group had greater segmental and relative correction at each level (segmental utility ratio mean 69% for 3CO vs 23% for MLG, p < 0.001). However, the 3CO group had lordotic differences between two adjacent lumbar disc pairs (range -0.5° to 9.0°, p = 0.009), while MLG was more harmonious (range 2.2°-6.5°, p > 0.4). MLG patients were more likely to undergo realignment to age-adjusted standards (OR 5.6, 95% CI 1.2-46.4; p = 0.033). MLG patients were less likely to develop neurological complications or undergo reoperation (OR 0.4, 95% CI 0.1-0.9; p = 0.041). Adjusted analysis revealed that MLG patients more often met a substantial clinical benefit in the Oswestry Disability Index score (OR 5.3, 95% CI 1.1-26.8; p = 0.043). MLG techniques showed better utility in lumbar distribution and age-adjusted global correction while minimizing neurological complications and reoperation rates by 2 years postoperatively. In selected instances, these techniques may offer the spine deformity surgeon a safer alternative when correcting severe adult spinal deformity.

Clinical and Radiographic Outcomes of Anterior Lumbar Interbody Fusion With Anterior Plate Fixation.

Reports on the outcomes following instrumented anterior lumbar interbody fusion (ALIF) with anterior plate fixation are limited. The aim of this study was to assess the clinical and radiographic outcomes of patients undergoing ALIF with anterior plate fixation. Methods: Medical records and radiographic imaging were reviewed for 100 patients who received ALIF with anterior plate fixation between 2008 to 2021 and completed at least one year of follow-up and postoperative imaging. Prospectively collected patient data included indication for surgery, BMI, age, number and location of levels treated, complications, reoperation rates, fusion rate, and measurements of global lordosis, disc space height, and segmental angulation. Results: A total of 100 patients were included in this study. The mean length of follow-up was 81.37 months. Changes in preoperative-to-postoperative Oswestry Disability Index (ODI) and Visual Analog Score (VAS) demonstrated improvements of 30.86% and 18.56%, respectively. Major vascular injuries occurred in 3% of the cases. A hardware failure rate of 5% was observed. The reoperation rate was 10%. The radiographic fusion rate derived from computed tomography (CT) and plain film was 95.45% and 88.87%, respectively. Postoperative global lordosis demonstrated a 6.08% increase. Postoperative segmental angulation measurements increased by 57.74%. No statistically significant differences in clinical or radiographic outcomes were observed based on the spine level of fusion or the number of fusions performed. Conclusions: ALIF with anterior plate fixation achieved an adequate fusion rate with improvements in ODI and VAS scores meeting minimal clinically important difference thresholds. Postoperative disc space heights demonstrated significant improvements compared to preoperative measurements.

Clinical and Radiographic Outcomes of Anterior Lumbar Interbody Fusions (ALIFs) Using a Titanium Cage with a Biomimetic Surface.

OBJECTIVE We analyzed clinical and radiographic outcomes in patients undergoing anterior lumbar interbody fusions (ALIFs) using a new biomimetic titanium fusion cage (Titan nanoLOCK interbody, Medtronic, Minneapolis, Minnesota). This specialized cage employs precise nanotechnology to stimulate inherent biochemical and cellular osteogenic reactions to the implant, aiming to amplify the rate of fusion. To our knowledge, this is the only study to assess early clinical and radiographic results in ALIFs. METHODS We conducted a retrospective review of data for patients who underwent single or multilevel ALIF using this implant between October 2016 and April 2021. Indications for treatment were spondylolisthesis, post-laminectomy syndrome, or spinal deformity. Clinical and radiographic outcome data for these patients were collected and assessed. RESULTS A total of 84 patients were included. The mean clinical follow-up was 36.6±14 months. At 6 months, solid fusion was seen in 97.6% of patients. At 12 months, solid fusion was seen in 98.8% of patients. Significant improvements were seen in patient-reported outcome measures (PROMs) (visual analog scale and Oswestry Disability Index) at 6 and 12 months compared to the preoperative scores (P<0.001). One patient required reoperation for broken pedicle screws 2 days after the ALIF. None of the patients required readmission within 90 days of surgery. No patients experienced an infection. CONCLUSIONS ALIF using a new titanium interbody fusion implant with a biomimetic surface technology demonstrated high fusion rates (97.6%) as early as 6 months. There was significant improvement in PROMs at 6 and 12 months.

The Evolution of Lateral Lumbar Interbody Fusion: A Journey from Past to Present.

Lumbar interbody fusion procedures have seen a significant evolution over the years, with various approaches being developed to address spinal pathologies and instability, including posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), and lateral lumbar interbody fusion (LLIF). LLIF, a pivotal technique in the field, initially emerged as extreme/direct lateral interbody fusion (XLIF/DLIF) before the development of oblique lumbar interbody fusion (OLIF). To ensure comprehensive circumferential stability, LLIF procedures are often combined with posterior stabilization (PS) using pedicle screws. However, achieving this required repositioning of the patient during the surgical procedure. The advent of single-position surgery (SPS) has revolutionized the procedure by eliminating the need for patient repositioning. With SPS, LLIF along with PS can be performed either in the lateral or prone position, resulting in significantly reduced operative time. Ongoing research endeavors are dedicated to further enhancing LLIF procedures making them even safer and easier. Notably, the integration of robotic technology into SPS has emerged as a game-changer, simplifying surgical processes and positioning itself as a vital asset for the future of spinal fusion surgery. This literature review aims to provide a succinct summary of the evolutionary trajectory of lumbar interbody fusion techniques, with a specific emphasis on its recent advancements.

Minimally Invasive L4-5 Oblique Lumbar Interbody Fusion With Robot-Assisted Single-Position Posterior Fixation: 2-Dimensional Operative Video.

We present here a 58-year-old female patient with L4-5 spondylolisthesis, who underwent a minimally invasive L4-5 oblique lumbar interbody fusion (OLIF) with robot-assisted bilateral posterior instrumented fixation in a single lateral position (Mazor X Stealth Edition, Medtronic). There has been interest in detailed video-based descriptions of single-position surgery with lateral approach interbody fusions, either in the prone or lateral decubitus position.1-6 Particularly, the addition of robotics has been shown to help increase overall operating efficiency in the lateral position with reduced case times even with the increased up-front robot setup time.7,8 The OLIF, also known as an anterior-to-psoas approach, allows for single-position posterior fixation and can be very effective at L4-5 where the anatomy of the iliac crest or lumbar plexus does not preclude this surgical corridor the way it could in the transpsoas lateral lumbar interbody fusion. Clinical outcomes between these 2 lateral approaches have been shown to be very good,9 and OLIF has reduced blood loss while still restoring alignment parameters compared with anterior lumbar interbody fusion, with better fusion and reduced subsidence compared with transforaminal lumbar interbody fusion.10,11 To our knowledge, this is the first video demonstrating a view of the OLIF approach through a high-definition retractor-based camera (MaxView Camera, Viseon Inc). There is no identifying patient information in this video. The participants and any identifiable individuals consented to publication of his/her image, and the patient consented to the procedure.

Spine

The February 2024 Spine Roundup360 looks at: Surgeon assessment of bone – any good?; Robotics reduces radiation exposure in some spinal surgery; Interbody fusion cage versus anterior lumbar interbody fusion with posterior instrumentation; Is robotic-assisted pedicle screw placement an answer to the learning curve?; Acute non-traumatic spinal subarachnoid haematomas: a report of five cases and a systematic review of the literature; Is L4-L5 lateral interbody fusion safe and effective?

Combined Anterior–Posterior vs. Posterior-Only Approach in Adult Spinal Deformity Surgery: Which Strategy Is Superior?

Introduction: Whether a combined anterior–posterior (AP) approach offers additional benefits over the posterior-only (P) approach in adult spinal deformity (ASD) surgery remains unknown. In a cohort of patients undergoing ASD surgery, we compared the combined AP vs. the P-only approach in: (1) preoperative/perioperative variables, (2) radiographic measurements, and (3) postoperative outcomes. Methods: A single-institution, retrospective cohort study was performed for patients undergoing ASD surgery from 2009 to 2021. Inclusion criteria were ≥5-level fusion, sagittal/coronal deformity, and 2-year follow-up. The primary exposure was the operative approach: a combined AP approach or P alone. Postoperative outcomes included mechanical complications, reoperation, and minimal clinically important difference (MCID), defined as 30% of patient-reported outcome measures (PROMs). Multivariable linear regression was controlled for age, BMI, and previous fusion. Results: Among 238 patients undergoing ASD surgery, 34 (14.3%) patients underwent the AP approach and 204 (85.7%) underwent the P-only approach. The AP group consisted mostly of anterior lumbar interbody fusion (ALIF) at L5/S1 (73.5%) and/or L4/L5 (38.0%). Preoperatively, the AP group had more previous fusions (64.7% vs. 28.9%, p &lt; 0.001), higher pelvic tilt (PT) (29.6 ± 11.6° vs. 24.6 ± 11.4°, p = 0.037), higher T1 pelvic angle (T1PA) (31.8 ± 12.7° vs. 24.0 ± 13.9°, p = 0.003), less L1-S1 lordosis (−14.7 ± 28.4° vs. −24.3 ± 33.4°, p &lt; 0.039), less L4-S1 lordosis (−25.4 ± 14.7° vs. 31.6 ± 15.5°, p = 0.042), and higher sagittal vertical axis (SVA) (102.6 ± 51.9 vs. 66.4 ± 71.2 mm, p = 0.005). Perioperatively, the AP approach had longer operative time (553.9 ± 177.4 vs. 397.4 ± 129.0 min, p &lt; 0.001), more interbodies placed (100% vs. 17.6%, p &lt; 0.001), and longer length of stay (8.4 ± 10.7 vs. 7.0 ± 9.6 days, p = 0.026). Radiographically, the AP group had more improvement in T1PA (13.4 ± 8.7° vs. 9.5 ± 8.6°, p = 0.005), L1-S1 lordosis (−14.3 ± 25.6° vs. −3.2 ± 20.2°, p &lt; 0.001), L4-S1 lordosis (−4.7 ± 16.4° vs. 3.2 ± 13.7°, p = 0.008), and SVA (65.3 ± 44.8 vs. 44.8 ± 47.7 mm, p = 0.007). These outcomes remained statistically significant in the multivariable analysis controlling for age, BMI, and previous fusion. Postoperatively, no significant differences were found in mechanical complications, reoperations, or MCID of PROMs. Conclusions: Preoperatively, patients undergoing the combined anterior–posterior approach had higher PT, T1PA, and SVA and lower L1-S1 and L4-S1 lordosis than the posterior-only approach. Despite increased operative time and length of stay, the anterior–posterior approach provided greater sagittal correction without any difference in mechanical complications or PROMs.

Radiographic Robustness of Lumbar Interbody Fusion Techniques.

Retrospective chart review. Lumbar interbody fusion (LIF) can be achieved with various techniques. Evidence supporting the long-term clinical advantages of one technique over another are inconclusive. The purpose of this study was to (1) determine the changes in sagittal parameters in the preoperative, intraoperative, and post-operative phase, (2) evaluate the radiographic maintenance of these parameters over time, and (3) compare the demographics and patient reported outcomes of patients undergoing various LIF techniques. We performed a retrospective chart review of patients with degenerative spine disease undergoing single level anterior (ALIF), lateral (LLIF), posterior (PLIF), or transforaminal (TLIF) lumbar interbody fusion. Data collected included patient demographics and diagnosis at time of surgery. Upright lumbar radiographs taken pre-operatively, intra-operatively, and post-operatively were measured for lumbar lordosis (LL), segmental lordosis (SL), posterior disc height (PDH), and foraminal height (FH). 194 patients in a single center were included. PDH and FH increased intra-operatively following ALIF (P < .0001), PLIF (P < .0001), LLIF (P < .0001), and TLIF (P < .0001). SL also increased intra-operatively for ALIF (P = .002) and LLIF (P = .0007). Compared to intra-operative radiographs, PDH and FH decreased at latest post-operative phase for ALIF (P < .03), LLIF (P < .003), TLIF (P < .001), and PLIF (P < .005). SL decreased for ALIF (P = .0008), and TLIF (P = .02). LL did not change postoperatively across techniques. Patient reported outcomes improved post-surgically and disability index decreased, but neither differed between techniques. LIF, regardless of technique, was shown to provide significant radiographic changes in PDH and FH. Techniques utilizing larger intervertebral cage sizes (ALIF/LLIF) improved SL. Single level LIF did not affect overall LL. No single technique displayed superior radiographic robustness over time.

The Impact of Posterior Intervertebral Osteophytes on Patient-Reported Outcome Measures After L5-S1 Anterior Lumbar Interbody Fusion and Transforaminal Lumbar Interbody Fusion.

Retrospective cohort study. (1) To develop a reliable grading system to assess the severity of posterior intervertebral osteophytes and (2) to investigate the impact of posterior intervertebral osteophytes on clinical outcomes after L5-S1 decompression and fusion through anterior lumbar interbody fusion (ALIF) and minimally-invasive transforaminal lumbar interbody fusion (MIS-TLIF). There is limited evidence regarding the clinical implications of posterior lumbar vertebral body osteophytes for ALIF and MIS-TLIF surgeries and there are no established grading systems that define the severity of these posterior lumbar intervertebral osteophytes. A retrospective analysis of patients undergoing L5-S1 ALIF or MIS-TLIF was performed. Preoperative and postoperative patient-reported outcome measures of the Oswestry Disability Index (ODI) and leg Visual Analog Scale (VAS) at 2-week, 6-week, 12-week, and 6-month follow-up time points were assessed. Minimal clinically important difference (MCID) for ODI of 14.9 and VAS leg of 2.8 were utilized. Osteophyte grade was based on the ratio of osteophyte length to foraminal width. "High-grade" osteophytes were defined as a maximal osteophyte length >50% of the total foraminal width. A total of 70 consecutive patients (32 ALIF and 38 MIS-TLIF) were included in the study. There were no significant differences between the two cohorts in patient-reported outcome measures or achievement of MCID for Leg VAS or ODI preoperatively or at any follow-ups. On multivariate analysis, neither the surgical approach nor the presence of high-grade foraminal osteophytes was associated with leg VAS or ODI scores at any follow-up time point. In addition, neither the surgical approach nor the presence of high-grade foraminal osteophytes was associated with the achievement of MCID for leg VAS or ODI at 6 months. ALIF and MIS-TLIF are both valid options for treating degenerative spine conditions and lumbar radiculopathy, even in the presence of high-grade osteophytes that significantly occupy the intervertebral foramen. 3.

BIOMECHANICAL AND RADIOLOGICAL ASSESSMENT OF AN ALIF STAND-ALONE DEVICE WITH INTEGRATED SCREWS AND ANGULAR-STABLE LOCKING PLATE AT L5/S1 AND ITS ASSOCIATION WITH LUMBAR BONE MINERAL DENSITY

Stand-alone anterior lumbar interbody fusion (ALIF) provides the opportunity to avoid supplemental posterior fixation. This may reduce morbidity and complication rate, which is of special interest in patients with reduced bone mineral density (BMD). This study aims to assess immediate biomechanical stability and radiographic outcome of a stand-alone ALIF device with integrated screws in specimens of low BMD.Eight human cadaveric spines (L4-sacrum) were instrumented with SynFix-LR™ (DePuy Synthes) at L5/S1. Quantitative computed tomography was used to measure BMD of L5 in AMIRA. Threshold values proposed by the American Society of Radiology 80 and 120 mg CaHa/mL were used to differentiate between Osteoporosis, Osteopenia, and normal BMD. Segmental lordosis, anterior and posterior disc height were analysed on pre- and postoperative radiographs (Fig 1). Specimens were tested intact and following instrumentation using a flexibility protocol consisting of three loading cycles to ±7.5 Nm in flexion-extension, lateral bending, and axial rotation. The ranges of motion (ROM) of the index level were assessed using an optoelectronic system.BMD ranged 58–181mg CaHA/mL. Comparison of pre- and postoperative radiographs revealed significant increase of L5/S1 segmental lordosis (mean 14.6°, SD 5.1, p &lt; 0.001) and anterior disc height (mean 5.8mm, SD 1.8, p &lt; 0.001), but not posterior disc height. ROM of 6 specimens was reduced compared to the intact state. Two specimens showed destructive failure in extension. Mean decrease was most distinct in axial rotation up to 83% followed by flexion-extension.ALIF device with integrated screws at L5/S1 significantly increases segmental lordosis and anterior disc height without correlation to BMD. Primary stability in the immediate postoperative situation is mostly warranted in axial rotation. The risk of failure might be increased in extension for some patients with reduced lumbar BMD, therefore additional posterior stabilization could be considered.For any figures or tables, please contact the authors directly.

Pedicle Subtraction Osteotomy Versus Multilevel Anterior Lumbar Interbody Fusion and Lateral Lumbar Interbody Fusion in the Treatment of Adult Spinal Deformity: Trends, Outcomes, and Cost.

Retrospective cohort study. The aim of this study was to compare the outcomes of pedicle subtraction osteotomy (PSO) with multilevel anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) in posterior long-segment fusion. PSO and ALIF/LLIF are 2 techniques used to restore lumbar lordosis and correct sagittal alignment, with each holding its unique advantages and disadvantages. As there are situations where both techniques can be employed, it is important to compare the risks and benefits of both. Patients aged 18 years or older who underwent PSO or multilevel ALIF/LLIF with posterior fusion of 7-12 levels and pelvic fixation were identified. 1:1 propensity score was used to match PSO and ALIF/LLIF cohorts for age, sex, and relevant comorbidities, including smoking status. Logistic regression was used to compare medical and surgical outcomes. Trends and costs were generated for both groups as well. ALIF/LLIF utilization in posterior long fusion has been steadily increasing since 2010, whereas PSO utilization has significantly dropped since 2017. PSO was associated with an increased risk of durotomy (P < 0.001) and neurological injury (P = 0.018). ALIF/LLIF was associated with increased rates of postoperative radiculopathy (P = 0.005). Patients who underwent PSO had higher rates of pseudarthrosis within 1 and 2 years (P = 0.015; P = 0.010), 1-year hardware failure (P = 0.028), and 2-year reinsertion of instrumentation (P = 0.009). Reoperation rates for both approaches were not statistically different at any time point throughout the 5-year period. In addition, there were no significant differences in both procedural and 90-day postoperative costs. PSO was associated with higher rates of surgical complications compared with anterior approaches. However, there was no significant difference in overall reoperation rates. Spine surgeons should select the optimal technique for a given patient and the type of lordotic correction required.