Increase In Segmental Lordosis Research Articles

Anterior Lumbar Interbody Fusion (ALIF) Versus Full-Endoscopic/Percutaneous TLIF With a Large-Footprint Interbody Cage: A Comparative Observational Study.

Exploratory prospective observational case-control study. Aim of this study was to compare clinical and radiologic outcome, as well as peri-operative complications, of anterior lumbar interbody fusion (ALIF) and full-endoscopic/percutaneous trans-Kambin transforaminal lumbar interbody fusion (pTLIF) with a large-footprint interbody cage. Patients that underwent elective ALIF and pTLIF with a large-footprint interbody cage were prospectively evaluated. Clinical follow-up was measured pre- and post-operatively with Visual Analogic Scale and Oswestry Disability Index scores. Radiologic outcome was assessed with a computed tomography scan and standing films at 12months. 44 patients underwent ALIF and 43 pTLIF surgery (total 87 cases). Clinical pre- and post-operative scores were comparable between both groups with 33.4months mean follow-up. Median surgical time was significantly lower for pTLIF (28minutes) compared to ALIF (72minutes). Radiologic outcome was favorable for ALIF with a significantly higher increase in segmental lordosis compared to pTLIF. Fusion rates did not significantly differ between both groups. ALIF showed significantly less cage subsidence than pTLIF. Complications included 9 (21%) cases with transitory post-operative radiculitis for ALIF and 12 (28%) for pTLIF; post-operative partial muscle weakness 3(6%) cases for ALIF and 4 (9%) for pTLIF. Two (4%) cases required revision surgery for pTLIF. ALIF and trans-Kambin pTLIF obtained comparable clinical outcome and fusion rates, while segmental lordosis restoration was favorable for ALIF. pTLIF required less surgery time and presented less intra-operative complications, while ALIF reported lower rates of post-operative subsidence, revision surgery and complications during follow-up.

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.

Transforaminal lumbar interbody fusion with placement of steerable banana cage: A single-center retrospective analysis of radiographic parameters of success

IntroductionThe transforaminal lumbar interbody fusion (TLIF) is among the most utilized methods for the surgical treatment of lumbar degenerative disc disease. The TLIF has advanced significantly with several iterative changes since its inception in the early 1980s, with the advent of several generations of interbody types, shapes, and materials. Steerable curvilinear interbodies are among the most recent innovations in this space and may offer biomechanical advantages, namely in preservation of lumbar and segmental lordosis. While radiographic parameters have been investigated for other cage shapes and lumbar interbody fusion techniques, no study has investigated postoperative radiographic outcomes specific to TLIFs done with curvilinear interbodies. MethodsThis study is a retrospective review of TLIFs performed with curvilinear interbodies between 2019 and 2022 at a single institution. Upright radiographs were obtained preoperatively and at several timepoints postoperatively. Radiographic variables including interspace height and segmental lordosis were collected. Results26 surgeries with 32 curvilinear interbodies were performed across 3 years. There was significant increase in segmental lordosis at the L4-L5 (p = 0.0183) and L5-S1 levels (p = 0.004) as well as interspace height postoperatively at levels L3-L4 (p = 0.011) and L4-L5 (p = 0.002). Pain as measured with the numeric rating scale significantly improved in the overall cohort postoperatively (p<0.001). ConclusionsTLIF with curvilinear interbody placement increases segmental lordosis and interspace height at the L4-L5 and L5-S1 levels, and increased interspace height at the L3-L4 and L4-L5 levels. Further investigation into additional radiographic parameters is warranted and expanded cohort size would benefit deeper analysis of other spinal levels. Implications for practiceAs an increasing number of cage designs and materials are brought to market, studies such as this allow for better understanding of cage specific outcomes allowing for better informed device selection.

212. ALIF as a salvage procedure for TLIF pseudarthrosis: a clinical outcome study

<h3>BACKGROUND CONTEXT</h3> Lumbar fusion procedures are at risk for pseudarthrosis as a complication. Despite its relative prevalence, few studies have characterized the clinical efficacy of salvage procedures. <h3>PURPOSE</h3> To characterize clinical outcomes following anterior lumbar interbody fusion (ALIF) as a salvage procedure for pseudarthrosis of transforaminal lumbar interbody fusion (TLIF). <h3>STUDY DESIGN/SETTING</h3> Retrospective. <h3>PATIENT SAMPLE</h3> Thirty-four ALIF patients. <h3>OUTCOME MEASURES</h3> VAS back and leg, ODI, SF-12 PCS, VR-12 PCS. <h3>METHODS</h3> A retrospective review of a surgical database of eligible procedures between November 2010 and June 2020 was performed. Inclusion criteria were as follows: single-level revision ALIF procedures performed at the index level for pseudarthrosis of TLIF. Patients were excluded if procedures were primary or performed for infectious, malignant or traumatic etiologies. Demographic and perioperative characteristics were collected. Additionally, time to revision, rates of 1-year arthrodesis, 6-month pseudarthrosis and postoperative complications were calculated. Radiographic measurements were performed to evaluate sagittal alignment and disc height at the preoperative, immediate postoperative and final postoperative timepoint. Differences between preoperative and final postoperative radiographic measurements were evaluated using a Student's t-test. Visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), 12-Item Short Form physical composite score (SF-12 PCS and VR-12 PCS) were collected preoperatively and postoperatively. Overall achievement of a minimum clinically important difference (MCID) was calculated using the following established values: 1.2 (VAS Back), 1.6 (VAS leg), 12.8 (ODI), 4.0 (SF-12 PCS). <h3>RESULTS</h3> A total of 34 patients who underwent an ALIF revision procedure at the index level were identified. Mean age was 46.7 years with 81.1% being male and 64.9% obese (body mass index: 30 kg/m²). A total of 83.8% had an ASA < 2 and 75.5% carried a CCI > 1. Mean time from index TLIF to salvage ALIF procedure was 21.3 months. Mean operative time was 135.3 minutes with an average blood loss of 75.0mL and hospital length of stay of 49.5 hours. The majority of procedures were performed at the L5-S1 level (73.5%). Patients demonstrated a one-year arthrodesis rate of 100.0% with 2/34 patients requiring an additional revision procedure at the index level for neuroforaminal bone growth. A total of six postoperative complications were observed with one patient suffering from a mild urinary tract infection, one with acute renal failure, one with a venous thromboembolism, one with altered mental status, and two with fever of unknown origin. Following ALIF salvage, there was a significant increase in segmental lordosis, mean anterior and posterior disc height, as well as average disc height (p≤0.037, all). Mean preoperative outcome scores were 7.2 ± 1.9 for VAS back, 6.8 ± 2.8 for VAS leg, 56.7 ± 16.5 for ODI, and 28.1 ± 10.9 for SF-12 PCS. Clinically relevant improvement of PROMs as measured by MCID achievement rates by one-year were 67.1% for VAS back, 57.1% for VAS leg, 40.0% for ODI and 37.5% for SF-12 PCS. <h3>CONCLUSIONS</h3> Use of ALIF as a salvage procedure at either the L4-5 or L5-S1 level for TLIF pseudoarthrosis demonstrated a high arthrodesis rate at one-year. Patients demonstrated high rates of MCID achievement for back and leg pain, as well as ODI. These results support the use of ALIF as a salvage procedure for failed TLIFs at the L4-5 and L5-S1 levels. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Restoring Segmental Spinal Alignment in Mini-Open Lateral Spinal Deformity Surgery-Determiners of Radiographic Outcome.

Both under- and overcorrection are risk factors for junctional failure after deformity correction. This study investigates which factors determine the segmental radiographic outcome in mini-open lateral deformity surgery. A single-center operative database was searched for patients undergoing multilevel mini-open lateral corrective surgery of degenerative spinal deformities. Preoperative and postoperative whole spine x-rays and computed tomography scans were compared for change in global and segmental alignment parameters. Linear regression analyses were performed to study the impact of surgical level, preoperative segmental sagittal Cobb angle, presence of bridging osteophytes, disc height, ankylosis of facet joints, and implantation site of the interbody device on postoperative increase in segmental lordosis, foraminal height, and foraminal width. A total of 49 patients were identified with a mean age of 68.7 years. At a mean, 4.2 segments were fused using a lateral approach, while the posterior stage comprised either minimally invasive surgery or open instrumentation. Upper instrumented vertebra was L2 (range T4-L3), and lower instrumented vertebra was L5 (range L4-pelvis) in most cases. Mean radiographic values pre- and postoperatively were as follows: C7 sagittal vertical axis +79.6 mm, +60 mm; lumbar lordosis 32.9°, 41.6°; pelvic tilt 21.1°, 21.8°; global coronal Cobb 16.3°, 10.8°; increase in segmental sagittal Cobb angle was significantly and inversely correlated with preoperative sagittal Cobb and positively correlated with preoperative coronal Cobb angle. No other variable showed significant correlations. Preoperative foraminal width and height showed significant and inverse correlation with change in postoperative foraminal width and height. Segmental sagittal correction is significantly influenced by preoperative loss of lordosis and coronal Cobb angle. Neither presence of osteophytes nor ankylosed facet joints, disc height, or implantation site of the interbody device had an influence on sagittal alignment goals. Only preoperative foraminal dimensions impact inversely the degree of foraminal decompression; no other factor investigated showed significant impact. Only preoperative lordosis and coronal Cobb angle influence sagittal correction.

Single-Position Prone Lateral Interbody Fusion Improves Segmental Lordosis in Lumbar Spondylolisthesis

Single-position surgery in prone position is a novel technique for lateral interbody fusion with pedicle screw fixation. We performed a radiographic comparison of patients treated for spondylolisthesis using the prone lateral (PL) transpsoas approach versus the traditional dual position (DP) approach (lateral decubitus then prone). Thirty consecutive patients with spondylolisthesis were treated using the PL approach (n= 15) versus the dual position approach (n= 15). Radiographic factors in the groups were retrospectively compared. The groups were similar for age, sex, body mass index, and implant size, but there were more 15° (vs. 10°) cages inserted in the dual position group. Radiographically the groups had similar baseline spinopelvic parameters, lumbar lordosis (LL), segmental lordosis, anterolisthesis, and disc height (P > 0.05). Postoperatively the PL group demonstrated a larger improvement in segmental lordosis (5.1° vs. 2.5°, P= 0.02), but not overall LL (6.3° vs. 3.1°, P= 0.14). Both groups had similar improvements in pelvic tilt, disc height, and spondylolisthesis reduction (P > 0.05). The mean relative distance of the implant from the posterior edge of the vertebral body was greater in the PL group (26% vs. 17%, P < 0.001) indicating a tendency for more anterior cage placement. However, there was no significant correlation between the relative cage position and the increase in segmental lordosis (P= 0.35), so this result alone did not explain the relative increase in lordosis seen. This is the first study to our knowledge to demonstrate an improvement in segmental lordosis for patients with single-level spondylolisthesis using the PL approach.

The minimally invasive interbody selection algorithm for spinal deformity.

Minimally invasive surgery (MIS) for spinal deformity uses interbody techniques for correction, indirect decompression, and arthrodesis. Selection criteria for choosing a particular interbody approach are lacking. The authors created the minimally invasive interbody selection algorithm (MIISA) to provide a framework for rational decision-making in MIS for deformity. A retrospective data set of circumferential MIS (cMIS) for adult spinal deformity (ASD) collected over a 5-year period was analyzed by level in the lumbar spine to identify surgeon preferences and evaluate segmental lordosis outcomes. These data were used to inform a Delphi session of minimally invasive deformity surgeons from which the algorithm was created. The algorithm leads to 1 of 4 interbody approaches: anterior lumbar interbody fusion (ALIF), anterior column release (ACR), lateral lumbar interbody fusion (LLIF), and transforaminal lumbar interbody fusion (TLIF). Preoperative and 2-year postoperative radiographic parameters and clinical outcomes were compared. Eleven surgeons completed 100 cMISs for ASD with 338 interbody devices, with a minimum 2-year follow-up. The type of interbody approach used at each level from L1 to S1 was recorded. The MIISA was then created with substantial agreement. The surgeons generally preferred LLIF for L1-2 (91.7%), L2-3 (85.2%), and L3-4 (80.7%). ACR was most commonly performed at L3-4 (8.4%) and L2-3 (6.2%). At L4-5, LLIF (69.5%), TLIF (15.9%), and ALIF (9.8%) were most commonly utilized. TLIF and ALIF were the most selected approaches at L5-S1 (61.4% and 38.6%, respectively). Segmental lordosis at each level varied based on the approach, with greater increases reported using ALIF, especially at L4-5 (9.2°) and L5-S1 (5.3°). A substantial increase in lordosis was achieved with ACR at L2-3 (10.9°) and L3-4 (10.4°). Lateral interbody arthrodesis without the use of an ACR did not generally result in significant lordosis restoration. There were statistically significant improvements in lumbar lordosis (LL), pelvic incidence-LL mismatch, coronal Cobb angle, and Oswestry Disability Index at the 2-year follow-up. The use of the MIISA provides consistent guidance for surgeons who plan to perform MIS for deformity. For L1-4, the surgeons preferred lateral approaches to TLIF and reserved ACR for patients who needed the greatest increase in segmental lordosis. For L4-5, the surgeons' order of preference was LLIF, TLIF, and ALIF, but TLIF failed to demonstrate any significant lordosis restoration. At L5-S1, the surgical team typically preferred an ALIF when segmental lordosis was desired and preferred a TLIF if preoperative segmental lordosis was adequate.

Clinical and Radiographic Outcomes of Lateral Interbody Fusion for Adjacent Segment Degeneration.

Retrospective cohort study. Assessment of outcomes in patients undergoing lateral interbody fusion as part of the surgical treatment of adjacent segment deterioration after previous lumbar spine fusion. Adult patients with previous lumbar posterior spinal fusion who presented with adjacent segment degeneration and stenosis refractory to nonoperative treatment and who underwent lateral lumbar interbody fusion were retrospectively analyzed. Clinical and radiographic outcomes were assessed and comparisons made between preoperative baseline and postoperative values. Thirty-six patients with symptomatic adjacent segment degeneration at 46 motion segments were included. Thirty (83.3%) of the 36 patients had complete relief of both preoperative lower extremity pain and back pain at the time of final follow-up. Six (16.7%) of the 36 patients had persistent pain, though in all 6 cases, the pain was less postoperatively than preoperatively. Oswestry Disability Index scores were improved significantly at final follow-up (P = .001). Compared with preoperative baseline parameters, initial and final postoperative radiographs had an increase in segmental lordosis (P < .001 and P < .001, respectively), increase in overall lumbar lordosis (P < .05 and P = .094, respectively), decrease in segmental coronal angulation (P = .63 and P < .01, respectively), decrease in overall coronal angulation (P = .063 and P = .009, respectively), and increase in intervertebral height (P < .001 and P < .001, respectively). Lateral lumbar interbody fusion achieves favorable clinical and radiographic outcomes for the treatment of adjacent segment degeneration after previous lumbar fusion. 4.

Supine anterior lumbar interbody fusion versus lateral position oblique lumbar interbody fusion at L5-S1: A comparison of two approaches to the lumbosacral junction

IntroductionAt L5-S1, anterior access can be performed with a supine anterior lumbar interbody fusion (ALIF) or lateral position oblique lumbar interbody fusion (LOLIF). We compared clinical and radiographic features of both approaches. MethodsA retrospective study of L5-S1 ALIF and LOLIF patients (2013–2018) by 3 spine surgeons and a vascular surgeon at our hospital was performed. Inclusion criteria were patients undergoing L5-S1 anterior surgery only without other anterior or lateral fusion levels, and data collected were patient demographics, cage parameters, perioperative variables, and radiographic parameters. 58 patients were included (33 ALIF and 25 LOLIF). ResultsThe average surgical time was 211.94 min for ALIF and 154.86 min for LOLIF (p < 0.001). The average blood loss was 214 ml for ALIF and 74 ml for LOLIF (p < 0.001). The average number of days to solid food was 2.55 for ALIF and 0.8 for LOLIF (p < 0.001). The average anterior L5-S1 disc height increase was 8.52 mm for ALIF and 5.02 mm LOLIF (p = 0.018), and the average posterior L5-S1 disc height increase was 3.34 mm for ALIF and 1.30 mm for LOLIF (p = 0.034). The average L5-S1 segmental lordosis increase was 6.82 degrees for ALIF and 7.63 degrees for LOLIF (p = 0.638). ConclusionThe LOLIF is a feasible option for L5-S1 anterior access compared to ALIF. However, supine ALIF afforded larger cages to be placed, resulting in greater postoperative disc height. There did not appear to be a significant difference in postoperative L5-S1 segmental lordosis between the two approaches.

61. ALIF vs TLIF for isthmic spondylolisthesis: differences in radiographic outcomes

BACKGROUND CONTEXT Patients with a diagnosis of isthmic spondylolisthesis have higher sacral slope, pelvic tilt, pelvic incidence and lumbar lordosis compared to patients without isthmic spondylolisthesis. Several fusion techniques have been used to treat isthmic spondylolisthesis in adults, including anterior lumbar interbody fusion (ALIF) and transforaminal interbody fusion (TLIF). Compared to other fusion techniques, ALIF has shown better sagittal alignment outcomes, particularly restoration of segmental lordosis. PURPOSE The purpose of this study was to evaluate which fusion technique provides the better radiological outcome for adult lumbar isthmic spondylolisthesis. STUDY DESIGN/SETTING This study was a retrospective analysis of prospectively collected data from a single, high-volume academic medical center. PATIENT SAMPLE Patients who underwent lumbar fusion for isthmic spondylolisthesis from 2014 to 2019 were included in the analysis. Surgery was indicated after failure of conservative treatment to address radiculopathy and/or neurogenic claudication. Patients were excluded if they were under 18 years of age at the time of surgery, presented with a tumor or infection, or underwent revision surgery. OUTCOME MEASURES Preoperative and postoperative radiographic parameters were collected including sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis, segmental lumbar lordosis, and the vertebral slip percentage. METHODS Patient and surgical characteristics including age, gender, smoking status, body mass index (BMI), Charlson Comorbidity Index (CCI), number of levels decompressed and number of levels fused were collected. Preoperative and final radiographic outcomes were obtained from an institutional electronic medical record. For analysis, patients were divided into two groups based on surgical technique: combined anterior fusion with posterior stabilization (ALIF-PLDF) or anterior and posterior fusion through a posterior approach (TLIF). RESULTS A total of 101 patients were included in final analysis, with 52 patients in the ALIF-PLDF group and 49 patients in the TLIF group. Mean age was greater in the TLIF group (p=0.017). Patients in the TLIF group were more likely to have a history of smoking (p=0.008), to have a greater CCI score (p=0.003), and to have higher number of levels decompressed. On analysis of radiographic parameters, preoperative sacral slope was higher in in the ALIF-PLDF group than the TLIF group (p=0.071). Postoperative overall lumbar lordosis was lower in the TLIF group (p=0.036). Postoperative segmental lumbar lordosis and the delta value for segmental lumbar lordosis were both lower in the TLIF group (p=0.030 and p=0.001). The TLIF group had a significant increase in PI-LL mismatch (p=0.032). Both groups had significant decrease in vertebral slip percent (p CONCLUSIONS Our data highlights that patients undergoing ALIF have a significant increase in segmental lordosis from their preoperative baseline. Interestingly, patients undergoing TLIF have significantly less postoperative change in segmental lumbar lordosis when compared to ALIF. When treating patients with isthmic spondylolisthesis, the ALIF approach has benefits not only in its capacity to restore segmental lordosis, but also by providing significant reduction in vertebral body slip. Our results suggest that, when compared to the TLIF approach, ALIF may be associated with better outcomes in terms of critical radiographic parameters. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

202. Hyperlordotic anterior interbody use without superior articulating process resection has an increased risk of Iiatrogenic neurological injury single level circumferential fusion

BACKGROUND CONTEXT Hyperlordotic (>20°) anterior interbody cages (HAI) may be utilized in anterior-posterior fusion (AP-F) in efforts to improve alignment. However, significant increase in segmental lordosis (SL) in HAI without superior articulating process resection (SAP) may result in foraminal stenosis and nerve root compression causing neurological deficits and radiculopathy. Additionally, HAI with SAP may increase SL without concomitant increase in lumbar lordosis (LL). PURPOSE Assess whether HAI without SAP in APF causes increased neurological complications. STUDY DESIGN/SETTING Single-center retrospective cohort study PATIENT SAMPLE A total of 158 patients undergoing single level APF were included, of which 73 had HAI placed and 85 had SAI placed. OUTCOME MEASURES Outcomes measures included radiographic analysis of pre- and postoperative LL and SL. Perioperative neurological complications were measured including new radiculopathy, iatrogenic motor deficit and malpositioned instrumentation or compressive hematoma causing deficit. Returns to OR within 30 or 90 days were measured including return for foraminal decompression, instrumentation revision, hematoma evacuation, and irrigation and debridement. METHODS Patients undergoing primary, single level, APF without SAP resection over a 5-year period were included. Patients were classified as HAI or SAI. Outcomes measures included perioperative neurological complications, returns to OR, pre- and postoperative LL and SL. Demographic, procedural and perioperative outcomes were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at p RESULTS A total of 158 patients (73 HAI, 85 SAI) were included. Age, gender, BMI and CCI were similar between groups. HAI without SAP resulted in significantly larger change in SL (9.84±5.84 vs 7.32±5.02 deg, p=0.001), without a significantly larger change in LL (8.16±1.11 vs 11.5±1.69 deg; p=0.641) compared with SAI. HAI without SAP increased overall incidence of neurological deficit (13.69% vs 3.53%; p=0.012), iatrogenic new cases of radiculopathy (10.95% vs 3.53%; p=0.045), and iatrogenic neurological motor deficit (13.69% vs 3.53%; p=0.012). Regression analysis demonstrated that increasing cage lordosis greater than 20° is an independent risk factor for neurological complications (p=0.046), as is higher preop SL (p=0.022). There were no significant differences in returns to OR. CONCLUSIONS We caution HAI implantation without SAP resection due to increased neurological complications from iatrogenic nerve root injury without the benefit of significantly improving LL correction. Use of HAI without SAP resection in single level APF should not be standard practice due to risk of neurological complications. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

The Minimally Invasive Interbody Selection Algorithm (MIISA) for Spinal Deformity

Abstract INTRODUCTION Multiple MIS interbody fusion options have been utilized as MIS deformity surgery has become more prevalent. However, at this time there is little guidance for approach selection for MIS deformity surgery. The minimally invasive interbody selection algorithm (MIISA) was created to provide a framework for rational decision making for surgeons who are considering MIS deformity surgery. METHODS A team of experienced spinal deformity surgeons developed the MIISA, incorporating the experience of a retrospective dataset from 223 MIS surgeries collected over a 5-yr period. The algorithm leads to one of 4 interbody approach options (including ALIF, ACR, LLIF, and TLIF) that allow either indirect or direct decompression of the neural elements, possibly restore disc space and foraminal height, and may restore lordosis. The algorithm was developed by fellowship-trained spine surgeons experienced with spinal deformity surgery and validated with the retrospective MIS database. RESULTS A total of 11 surgeons completed 223 MIS deformity surgeries with 661 interbody devices. These cases were reviewed and the type of interbody approach used at each level from L1-S1 was recorded. The MIISA was created with substantial agreement. Surgeons preferred lateral approaches for L1-L2, L2-L3, and L3-L4. They preferred lateral approaches at L4-L5, but this was muted by more use of TLIF and ALIF at that level. They preferred TLIF to ALIF at L5-S1. The increase in segmental lordosis at L2-L3 was significantly greater with LLIF than TLIF. The increase in segmental lordosis at L4-L5 was significantly greater with ALIF than LLIF or TLIF. The increase in segmental lordosis at L5-S1 was greater with ALIF than TLIF. CONCLUSION The use of the MIISA provides consistent and straightforward guidance for surgeons who are considering an MIS approach for the treatment of patients with adult spinal deformity. The application of this algorithm could provide a platform for surgeons to achieve the desired goals of surgery.

Anterior Lumbar Interbody Fusion (ALIF) versus Oblique Lateral Interbody Fusion (OLIF) at L5-S1: A Comparison of Two Approaches to the Lumbosacral Junction

Abstract INTRODUCTION The oblique lateral interbody fusion OLIF is an alternative anterior approach to the lumbar spine at L5-S1, and it is unknown how it compares to anterior lumbar interbody fusion ALIF. This abstract is to compare the radiographic and clinical factors of ALIF and OLIF at L5-S1 only. METHODS A retrospective review of patients who underwent ALIF or OLIF at L5-S1 only at the University of California San Francisco (2013-2018) was performed. Data collected were demographics, cage parameters, perioperative factors, and radiographic parameters. RESULTS A total of 58 patients were included (33 ALIF and 25 OLIF). The average surgical time was 211.94 min for ALIF and 154.86 min for OLIF (P &lt; .001). The average blood loss was 214 ml for ALIF and 74 ml for OLIF (P &lt; .001). The average day to solid food was 2.55 for ALIF and 0.8 for OLIF (P &lt; .001). The average cage height was 14.78 mm for ALIF and 12.9 mm (P &lt; .001) for OLIF. The average cage lordosis was 15.45° for ALIF and 12.68° (P = .76) for OLIF. Average anterior L5-S1 disc height increase was 8.52 mm (ALIF) and 5.02 mm (OLIF) (P = .018), and average posterior L5-S1 disc height increase was 3.34 mm (ALIF) and 1.30 mm (OLIF) (P = .034). The average L5-S1 segmental lordosis increase was 6.82° for ALIF and 7.63° for OLIF (P = .638). CONCLUSION Patients who underwent OLIF at L5-S1 had shorter ileus duration compared to ALIF and comparable operative times and blood loss. ALIF afforded larger cages to be placed, resulting in greater disc height, but there was no significant difference in L5-S1 segmental lordosis.

Anterior cervical discectomy and fusion can restore cervical sagittal alignment in degenerative cervical disease.

The purpose of this study was to evaluate its effect on the restoration and maintenance of cervical sagittal alignment in usual cervical degenerative diseases without preoperative sagittal malalignment. We retrospectively evaluated 108 patients who were diagnosed with degenerative cervical disease and underwent ACDF (allograft and plating) with > 1-year follow-up. For radiographic evaluation, we analysed segmental and C2-7 cervical lordosis, disc height, C2-7 sagittal vertical axis (SVA), T1 slope, and T1 slope minus C2-7 lordosis (T1S - CL) in lateral X-ray. Clinical assessment was based on arm VAS, neck VAS, and NDI scores. Correlation analysis was performed across the pre-post-changes in radiological parameters. Correlations between the changes in radiological and clinical parameters at final follow-up were also analysed. C2-7 lordosis was 7.13° preoperatively and increased to 13.06° (p < 0.001) and maintained at 10.08° at final follow-up (p = 0.007). Segmental lordosis increased from 0.66° to 8.33° and maintained at 5.19° (p < 0.001). Segmental disc height was 4.67mm preoperatively (increased to 7.13mm postoperatively and decreased to 5.74mm at final follow-up) (p < 0.001). SVA distance (31.53mm to 30.02mm) (p = 0.750) and T1 slope (30.03° to 31.37°) did not show meaningful change after surgery. Increase in segmental lordosis was correlated to an increase in C2-7 lordosis (p < 0.001). C2-7 SVA change correlated with both the T1 slope change (p < 0.001) and T1S - CL (p = 0.012). Change in SVA was correlated to a change in segmental lordosis and T1 slope (p = 0.003, p = 0.014). Clinical outcomes did not correlate with radiological findings. ACDF for the treatment of degenerative cervical disease without preoperative deformity was effective in restoring cervical sagittal alignment. Improvement of segmental lordosis related to an improvement in C2-7 lordosis and SVA. Radiological sagittal alignment did not show any relation with clinical outcomes in usual degenerative cases.

Segmental Lordosis of the Spondylolytic Vertebrae in Adolescent Lumbar Spondylolysis: Differences between Bilateral L5 and L4 Spondylolysis.

Study DesignRetrospective study.PurposeThis study aimed to investigate whether segmental lumbar hyperlordosis of the affected vertebra in patients with spondylolysis occurs only at L5 or also occurs at L4.Overview of LiteratureTo the best of our knowledge, increase in segmental lordosis of the spondylolytic vertebrae has only been investigated in bilateral L5 spondylolysis; it has not been examined at different levels of bilateral spondylolysis. According to the characteristics of segmental lordosis in bilateral L5 spondylolysis, patients with bilateral L4 spondylolysis may also have increased segmental lordosis of the L4 vertebra.MethodsPatients with bilateral spondylolysis of the L5 or L4 vertebra in 2013–2015 were retrospectively identified from the hospital database. Standing lateral lumbar radiographs were assessed for the angle of segmental lordosis of the L5 and L4 vertebra, sacral slope, and lumbar lordosis. The differences in segmental lordosis of the L5 and L4 vertebra, sacral slope, and lumbar lordosis were determined using non-paired Student t-test.ResultsOverall, 15 cases of bilateral L4 spondylolysis and 41 cases of bilateral L5 spondylolysis satisfied the inclusion and exclusion criteria. Lordosis of the L4 vertebra was significantly greater in the bilateral L4 spondylolysis group (24.2°±7.0°) than that in the L5 spondylolysis group (20.3°±6.1°, p=0.047). Lordosis of the L5 vertebra was significantly lower in the L4 spondylolysis group (27.7°±8.2°) than that in the L5 spondylolysis group (32.5°±7.3°, p=0.040). The sacral slope and lumbar lordosis did not significantly differ between the groups.ConclusionsAdolescent patients with bilateral spondylolysis have segmental hyperlordosis of the affected vertebra not only at the L5 level but also at the L4 level.

Comparison of Stand-Alone, Transpsoas Lateral Interbody Fusion at L3-4 and Cranial vs Transforaminal Interbody Fusion at L3-4 and L4-5 for the Treatment of Lumbar Adjacent Segment Disease

Retrospective cohort study. To compare outcomes and complications of stand-alone minimally invasive lateral interbody fusion (LIF) vs revision posterior surgery for the treatment of lumbar adjacent segment disease. Adults who underwent LIF or transforaminal lumbar interbody fusion (TLIF) for adjacent segment disease were compared. Exclusion criteria: >grade 1 spondylolisthesis, posterior approach after LIF, and L5/S1 surgery. Patient demographics, estimated blood loss, hospital length of stay, complications, reoperations, health-related quality of life measures, and radiographs were examined. Data were analyzed with the χ2, Wilcoxon signed rank, and Mann-Whitney U tests. A total of 17 LIF and 16 TLIF patients were included. Demographics were similar. Follow up was similar (LIF: 22.9 ± 11.8 months vs TLIF: 22.0 ± 4.6 months; P = .86). The LIF patients had significantly less blood loss (LIF: 36 ± 16 mL vs TLIF: 700 ± 767 mL; P < .001) and shorter length of stay (LIF: 2.6 ± 2.9 days vs TLIF: 3.3 ± 0.9 days; P = .001). There were no intraoperative complications. Revision rate was 4 of 17 in LIF and 3 of 16 in TLIF (P = .73). Baseline health-related quality of life and radiographic measurements were similar. In both groups, back and leg pain scores significantly improved, and in LIF, the Owestry Disability Index, and EuroQol-5D significantly improved. The LIF had a significant increase in intervertebral height (LIF: 4.8 ± 2.9 mm, P < .001, TLIF: 1.3 ± 3.4 mm, P = .37), which was significantly greater for LIF than TLIF (P = .002). Similarly, LIF had a significant increase in segmental lordosis (LIF: 5.6° ± 4.9°, P < .001, TLIF: 3.6° ± 8.6°, P = .16), which was not significantly different between groups. Patients with adjacent segment disease may receive significant benefit from stand-alone LIF or TLIF. The LIF offers advantages of less blood loss and a shorter hospital stay. 3.

Single-Level Lateral Lumbar Interbody Fusion for the Treatment of Adjacent Segment Disease: A Retrospective Two-Center Study.

A retrospective case series. The aim of this study was to assess the postoperative outcome after single-level lateral lumbar interbody fusion (LLIF) for adjacent segment disease (ASD). Although there is a plethora of literature on ASD following traditional arthrodesis techniques, literature on ASD following LLIF is limited. Vice versa, the surgical outcome after LLIF for the treatment of ASD remains to be elucidated. Patients who underwent single-level LLIF for ASD at two institutions (March 2006-April 2012) were included, and the medical records, operative reports, radiographic imaging studies, and office records reviewed. Out of 523 LLIF patients, 52 met the inclusion criteria, and were postoperatively followed for 16.1 ± 9.8 months (range: 5-44). When comparing the pre-operative data with both the first and most recent follow-up postoperatively, LLIF resulted in a reduction in back pain (P < 0.001, and P < 0.001, respectively) and leg pain (P < 0.001, and P < 0.001, respectively), increase in segmental lordosis (P = 0.003, and P = 0.014, respectively), decrease in segmental coronal angulation (P < 0.001, and P = 0.003, respectively), and increase in intervertebral height (P < 0.001, and P < 0.001, respectively) at the surgical level. The reoperation rate related to the LLIF procedure was 21.2% (11/52), which was performed after an average of 14.6 ± 10.1 months (range: 3.3-31.0). Eight out of 11 patients (72.7%) in the reoperation subgroup underwent standalone LLIF, whereas only 23 out of 41 patients (56.1%) without a reoperation underwent standalone LLIF (P = 0.491). There was a trend toward a higher fusion rate in patients who underwent circumferential fusion than the standalone subgroup (87.5% vs. 53.8%; P = 0.173). LLIF may be an effective surgical treatment option for ASD with regard to both the clinical and radiographic outcome in a large proportion of cases. Although standalone LLIF is associated with a narrower spectrum of adverse effects than circumferential fusion, posterior instrumentation may be necessary to increase segmental stability. 4.

Sagittal Deformity Correction during the Lateral Transpsoas Approach with Hyperlordotic Interbody Grafting, Adjunctive ALL Release, and Subsequent Smith–Peterson Osteotomy

Introduction Traditionally, surgical intervention for patients with thoracolumbar sagittal imbalance relied on posterior column shortening techniques such as the Smith–Peterson osteotomy (SPO) and pedicle subtraction osteotomy (PSO). The lateral retroperitoneal, transpsoas approach has been proven to afford significant coronal deformity correction; however, the evidence for its use in the sagittal deformity correction is less robust. Recently, the use of hyperlordotic grafts has provided all the benefits of the transpsoas approach while also allowing for sagittal deformity correction. Hyperlordotic interbody grafts and a subsequent SPO can theoretically provide a similar sagittal correction as provided by a PSO or multiple SPOs while minimizing the associated morbidities. Materials and Methods This is a retrospective review examining the preoperative and postoperative segmental lordosis after placement of a hyperlordotic cage and subsequent SPO. A total of 22 patient charts were reviewed. The mean patient age was 58.6. There were 8 males and 14 females. A 20-degree hyperlordotic cage was utilized at four intervertebral levels. The 30-degree cage was used at 19 levels. The surgical procedure involved the release of the anterior longitudinal ligament and placement of a hyperlordotic graft (NuVasive CoRoent XL-Hyperlordotic) via the lateral, retroperitoneal, transpsoas approach followed by posterior instrumentation and SPO at that level. In each instance, the hyperlordotic graft and subsequent SPO were part of a large, multilevel deformity correction and were not simply performed as a standalone procedure. Results Hyperlordotic cages were placed from T12–L1 to L4–L5 in this series. A total of 10 cages were placed at the L3–L4 interspace. The mean preoperative lordosis was 0.4 and 4.2 degrees in the 20 and 30-degree cohorts, respectively. The mean postoperative, segmental lordosis was 23.0 and 28.2 degrees in the two groups, yielding a mean correction of 22.6 degrees with the 20-degree cage and 24.0 degrees with the 30-degree cage. The 30-degree cage yielded a sagittal correction of 8.5 to 54.0 degrees. A correction of greater than 30 degrees was achieved in five cases. The single case with less than 10 degrees of lordosis restoration resulted from graft subsidence. The greatest increase in lordosis occurred in patients with the most significant preoperative segmental kyphosis. Conclusion Segmental lordosis increase of approximately 20 to 25 degrees can be expected with the placement of either a 20- or 30-degree hyperlordotic cage via the transpsoas approach with subsequent SPO at that level. This hybrid approach provides a degree of correction similar to a PSO without the associated morbidity.

Radiological evaluation of anterior lumbar fusion using PEEK cages with adjacent vertebral autograft in spinal deformity long fusion surgeries.

The aim of this study was to evaluate the radiographic characteristics of polyetheretherketone (PEEK) cages packed with adjacent vertebral autograft material in lumbar anterior lumbar interbody fusion (ALIF) in spinal deformity long fusion surgeries. This is a retrospective radiographic study. From April 2008 to April 2012, 40 patients (5 males and 35 females, mean age 67 ± 9 years) with coronal and/or sagittal spine deformities underwent staged corrective surgery combined with lumbar ALIF using PEEK cages at the L3-L4, L4-L5 or L5-S1 segment with posterior long (≥ 4 levels) instrumentation. The mean follow-up time was 27.5 months (13-49 months). We examined the interbody fusion rate and cage subsidence at 3 months postoperatively and final follow-up. Additionally, we evaluated the distance of cage migration at final follow-up and the improvement in lumbar lordosis. The rate of "collapse" of the adjacent vertebra where the autograft was harvested was assessed at the final follow-up. Finally, we examined the cage-related postoperative complications in this series. Solid interbody fusion was achieved in 96.4 % (81/84) of the levels at the final follow-up. A mild forward cage migration was observed, and the mean migration distance at final follow-up was 0.83 mm in L3/4, 0.36 mm in L4/5 and 0.55 mm in L5/S1. There was cage subsidence observed in 8.3 % (7/84) of the levels. In all patients, the PEEK cage maintained a significant increase in segmental lordosis at all postoperative visits. However, a mild reduction in segmental lordosis still occurred with time. The adjacent lumbar vertebral bodies where the autografts were harvested appeared to be intact in height radiologically at the final follow-up. There were no postoperative complications due to bone harvesting or cage insertion. Proximal junctional kyphosis was found in one patient who underwent a subsequent revision surgery. The use of lumbar ALIF with PEEK cages and adjacent vertebral autografts in spinal deformity long fusion surgeries is an effective and safe procedure. The allograft filler is safe and effective in maintaining the shape of harvested vertebrae. Additional long-term follow-up studies are needed to further justify its use.

Microscopic anterior foraminal decompression combined with anterior lumbar interbody fusion

Background contextAnterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PPF) provides successful surgical outcomes to isthmic spondylolisthesis patients with indirect decompression through foraminal volume expansion. However, indirect decompression through ALIF followed by PPF may not obtain a successful surgical outcome in patients with isthmic spondylolisthesis accompanied by foraminal stenosis caused by a posterior osteophyte or foraminal sequestrated disc herniation. Thus far, there has been no report of foraminal decompression through anterior direct access in the lumbar spine. PurposeThis study aims to describe the new surgical technique of microscopic anterior foraminal decompression and to analyze the clinical outcomes and radiologic results of the microscopic anterior decompression during ALIF followed by PPF. Study design/SettingWe conducted a multisurgeon, retrospective, clinical series from a single institution. Patient sampleThis study was carried out from March 2007 to July 2010 and included 40 consecutive patients with isthmic spondylolisthesis accompanied by foraminal stenosis caused by posterior osteophyte or foraminal sequestrated disc herniation undergoing microscopic anterior foraminal decompression during ALIF followed by PPF. Outcome measuresThe visual analog scales (VAS) of back and leg pain and the Oswestry disability index were measured preoperatively and at the last follow-up. MethodsPostoperative computed tomography and magnetic resonance imaging measured whether decompression of neural structure had been made and morphometric change of the foramen and the amount of resected bone. Moreover, segmental lordosis, whole lumbar lordosis, disc height, and degree of listhesis were measured through X-ray examination before the operation and at the last follow-up; we also verified whether fusion had been achieved. ResultsSuccessful decompression was confirmed in both patients with foraminal stenosis caused by posterior osteophyte and those with foraminal sequestrated disc herniation. Clinically, compared with before the surgery, the VAS (leg and back) and the Oswestry disability index significantly decreased at the last follow-up (p=.000). With regard to radiology, at the last follow-up all patients had bone fusion on X-ray examination, and an increase in disc height, a reduction in the degree of listhesis, an increase in segmental lordosis, and an increase in whole lumbar lordosis were significant in both groups (p=.000) compared with before the surgery. Foraminal volume, foraminal width, and foraminal height also significantly increased postoperatively compared with before the operation (p=.000). The height, width, and dimension of resected body were 4.61±1.05 mm, 7.92±1.42 mm, 17.15±4.96 mm2, respectively, in patients with foraminal stenosis caused by a posterior osteophyte, and 3.88±0.92 mm, 6.8±1.29 mm, and 13.12±2.25 mm2, respectively, in patients with foraminal sequestrated disc. ConclusionsThe microscopic anterior foraminal approach provides successful foraminal decompression. Combined with ALIF and PPF, this approach shows a good surgical outcome in patients with isthmic spondylolisthesis accompanied by foraminal stenosis caused by a posterior osteophyte or those with foraminal sequestrated disc herniation.