Results and complications after 2-level axial lumbar interbody fusion with a minimum 2-year follow-up

Object Axial lumbar interbody fusion (AxiaLIF) is a minimally invasive presacral surgical technique that damages neither the anulus fibrosus nor the anterior or posterior longitudinal ligaments. The technique was initially designed and used for L5–S1 interbody fusions and recently was extended to 2-level fusions (L4–5 and L5–S1). Until now, only biomechanical and radiological studies have discussed the feasibility of this new indication, and no clinical study has been published. The purpose of this article is to report results and complications associated with 2-level presacral AxiaLIF with a minimum of 24 months of follow-up. Methods In this prospective, nonrandomized, single-center study, 27 patients underwent presacral AxiaLIF surgery at the L4–5 and L5–S1 levels. Clinical outcomes were assessed using the visual analog scale for back and leg symptoms and the Oswestry Disability Index. Radiographic parameters, such as disc height, segmental lordosis, and bone fusion, were analyzed using radiographs and CT scans. Complications and revision surgeries were recorded as needed. The minimum follow-up was 24 months (up to 72 months). Results There were no intraoperative complications. One major complication was observed: a patient developed septicemia that resolved after proper care. Clinical outcomes scores showed overall improvement in pain and physical function. During follow-up, the following complications were observed in the construct: screw breakage (14.8%), proximal/distal transsacral rod detachment (11.1%), radiolucency around the transsacral rod (52%), and cephalic rod migration (24%). Disc height gain was reported early after surgery, but at the 24-month follow-up the disc space was diminished in comparison with the preoperative status. Compared with preoperative values, the 24-month results showed loss of segmental lordosis. Only 22% of all treated levels were considered to have solid fusion at the 24-month radiological evaluation. Conclusions Patients undergoing presacral 2-level AxiaLIF experienced satisfactory short-term clinical outcomes; however, complications were commonly seen on imaging studies obtained 24 months postoperatively. Additional studies are required to better understand the 2-level indications for this technique.

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Feasibility of Endoscopic Transforaminal Lumbar Interbody Fusion(eTLIF) through the Posterior Paraspinal Approach: Technical Note and Preliminary Result

10.21203/rs.3.rs-28307/v2 ◽

2020 ◽

Author(s):

Hyeun-Sung Kim ◽

Harshavardhan Dilip Raorane ◽

Pang Hung Wu ◽

Dong Hwa Heo ◽

Yeon Jin Yi ◽

...

Keyword(s):

Lumbar Lordosis ◽

Interbody Fusion ◽

Plain Radiograph ◽

Transforaminal Lumbar Interbody Fusion ◽

Disc Height ◽

Lumbar Interbody Fusion ◽

Disc Space ◽

Paraspinal Approach ◽

Segmental Lordosis

Abstract Background: Implementation of endoscopic spine surgery in the management of degenerative lumbar diseases has significantly reduced the need for fusion surgeries. The performance of a MIS-TLIF using an endoscope offers some distinct advantages, such as allowing better visualization the disc space, enhanced endplate preparation and contralateral decompression. The objective of this study was to analyze the preliminary clinical and radiological outcomes of the technique of endoscopic transforaminal lumbar interbody fusion (eTLIF).Materials and Methods: eighteen consecutive patients with degenerative lumbar disease underwent eTLIF through a conventional paraspinal approach. Their clinical outcomes were evaluated with visual analog scale(VAS) leg pain score, Oswestry Disability Index(ODI) and the MacNab's criteria; radiological outcome measured with segmental lordosis, global lumbar lordosis, disc height on plain radiograph and percentage of potential fusion mass on CT scan at pre-operative, post-operative and final follow up period. Intra operative and post-operative complications were noted.Results: Mean age was 63. 71 years and Mean follow-up periods was 7.78 months. In the X-ray result, mean segmental lordosis angle(SLA) improved in pre-operative/post-operative/follow-up period 9.87±2.74 degree/ 11.79±3.74 degree/ 10.56±3.69 degree (p > 0.01); mean lumbar lordosis angle(LLA) improved 37.1±7.04 degree/ 39.2±7.13 degree/ 35.7±7.25 degree (p > 0.01). Mean preoperative disc height(DH) improved from 8.97±1.49 mm/ 12.34±1.39 mm/ 11.44±1.98 mm (p < 0.01). In the CT result, Average percentage of fusion mass was 42.61%. VAS was improved significantly, 7.67±1.13 / 3.39±1.38 / 2.5±1.34 and ODI was improved significantly, 74.9±8.03/ 34.56±8.80 / 27.76±8.64 by each preoperative / postoperative / final follow-up. In the clinical result, excellent was 5 cases and good was 13 cases. Conclusion: According to the results of this study, endoscopic TLIF was feasible procedure with an advantage of better visualization and preservation of endplate, minimal blood loss and minimal post-operative pain with early mobilization. In addition, the fusion volume as measured on post-operative CT scans, occupied 40% to 50% of disc space along with the use of 3D printed cages expected to give higher fusion rates. In conclusion, our preliminary results show that endoscopic TLIF is considered to be a viable surgical procedure with further long-term follow-up warranted.

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Computerized tomography evaluation of a resorbable implant after transforaminal lumbar interbody fusion

Neurosurgical FOCUS ◽

10.3171/foc.2004.16.3.11 ◽

2004 ◽

Vol 16 (3) ◽

pp. 1-6 ◽

Cited By ~ 27

Author(s):

Timothy R. Kuklo ◽

Michael K. Rosner ◽

David W. Polly

Keyword(s):

Computerized Tomography ◽

Interbody Fusion ◽

Case Series ◽

Ct Scanning ◽

Transforaminal Lumbar Interbody Fusion ◽

Delayed Union ◽

Lumbar Interbody Fusion ◽

Disc Space ◽

Screw Breakage

Object Synthetic bioabsorbable implants have recently been introduced in spinal surgery; consequently, the indications, applications, and results are still evolving. The authors used absorbable interbody spacers (Medtronic Sofamor Danek, Memphis, TN) packed with recombinant bone morphogenetic protein (Infuse; Medtronic Sofamor Danek) for single- and multiple-level transforaminal lumbar interbody fusion (TLIF) procedures over a period of 18 months. This is a consecutive case series in which postoperative computerized tomography (CT) scanning was used to assess fusion status. Methods There were 22 patients (17 men, five women; 39 fusion levels) whose mean age was 41.6 years (range 23–70 years) and in whom the mean follow-up duration was 12.4 months (range 6–18 months). Bridging bone was noted as early as the 3-month postoperative CT scan when obtained; solid arthrodesis was routinely noted between 6 and 12 months in 38 (97.4%) of 39 fusion levels. In patients who underwent repeated CT scanning, the fusion mass appeared to increase with time, whereas the disc space height remained stable. Although the results are early (mean 12-month follow-up duration), there was only one noted asymptomatic delayed union/nonunion at L5–S1 in a two-level TLIF with associated screw breakage. There were no infections or complications related to the cages. Conclusions The bioabsorbable cages appear to be a viable alternative to metal interbody spacers, and may be ideally suited to spinal interbody applications because of their progressive load-bearing properties.

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Feasibility of Endoscopic Transforaminal Lumbar Interbody Fusion through the Posterior Paraspinal Approach: Technical Note and Preliminary Result

10.21203/rs.3.rs-28307/v1 ◽

2020 ◽

Author(s):

Hyeun-Sung Kim ◽

Harshavardhan Dilip Raorane ◽

Pang Hung Wu ◽

Dong Hwa Heo ◽

Yeon Jin Yi ◽

...

Keyword(s):

Lumbar Lordosis ◽

Interbody Fusion ◽

Plain Radiograph ◽

Transforaminal Lumbar Interbody Fusion ◽

Disc Height ◽

Graft Material ◽

Lumbar Interbody Fusion ◽

Paraspinal Approach ◽

Segmental Lordosis

Abstract Background: The implement of endoscopic spinal surgery into degenerative spinal disease has minimized the requirement of fusion procedures. However, it is still necessary to develop endoscopic spine surgery in certain patients requiring fusion such as instability. We performed a full-endoscopic transforaminal lumbar interbody fusion(eTLIF) through a conventional paraspinal approach. The feasibility of procedure and early outcome were evaluated.Materials and Methods: eighteen consecutive patients with degenerative lumbar disease underwent eTLIF through a conventional paraspinal approach. Their clinical outcomes were evaluated with visual analog scale(VAS) leg pain score, Oswestry Disability Index(ODI) and the MacNab's criteria; radiological outcome measured with segmental lordosis, global lumbar lordosis, disc height on plain radiograph and percentage of potential fusion mass on CT scan at pre-operative, post-operative and final follow up period. intra operative and post-operative complications noted.Results: Mean age was 63. 71 years and Mean follow-up periods was 7.78 months. According to the level, L2-3 (1 case), L3-4 (4 cases), L4-5 (13 cases) and L5-S1 (2 cases). In the X-ray result, mean segmental lordosis angle(SLA) improved in pre-operative/post-operative/follow-up period 9.87±2.74 degree/ 11.79±3.74 degree/ 10.56±3.69 degree (p > 0.01); mean lumbar lordosis angle(LLA) improved 37.1±7.04 degree/ 39.2±7.13 degree/ 35.7±7.25 degree(p > 0.01). Mean preoperative disc height(DH) improved from 8.97±1.49 mm/ 12.34±1.39 mm/ 11.44±1.98 mm (p < 0.01). In the CT result, Average percentage of fusion mass was 42.61%. VAS was improved significantly, 7.67 / 3.39 / 2.5 and ODI was improved significantly, 74.9 / 34.56 / 27.76 by each preoperative / postoperative / final follow-up. In the clinical result, excellent was 5 cases and good was 13 cases. Conclusion: According to the results of this study, eTLIF was competent enough to perform as open TLIF. and good results were obtained in the form of endplate preservation, disc height restoration, minimal blood loss and post-operative pain with early mobilization. In addition, the fusion volume including the cage and the bone graft material occupies 40% to 50% of disc space is expected to give sufficient fusion by using 3D printed cages which gives the high fusion rate. In conclusion, eTLIF is considered to be a viable surgical procedure.

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Effect of segmental lordosis on the clinical outcomes of 2-level posterior lumbar interbody fusion for 2-level degenerative lumbar spondylolisthesis

Journal of Neurosurgery Spine ◽

10.3171/2019.4.spine181463 ◽

2019 ◽

Vol 31 (5) ◽

pp. 670-675

Author(s):

Yoshifumi Takahashi ◽

Shinya Okuda ◽

Yukitaka Nagamoto ◽

Tomiya Matsumoto ◽

Tsuyoshi Sugiura ◽

...

Keyword(s):

Clinical Outcomes ◽

Recovery Rate ◽

Interbody Fusion ◽

Posterior Lumbar Interbody Fusion ◽

Lumbar Interbody Fusion ◽

Spinopelvic Parameters ◽

Outcome Group ◽

Segmental Lordosis ◽

The Relationship

OBJECTIVEAlthough the importance of spinopelvic sagittal balance and its implications for clinical outcomes of spinal fusion surgery have been described, to the authors’ knowledge there have been no reports of the relationship between spinopelvic alignment and clinical outcomes for 2-level posterior lumbar interbody fusion (PLIF). The purpose of this study was to elucidate the relationship between clinical outcomes and spinopelvic sagittal parameters after 2-level PLIF for 2-level degenerative spondylolisthesis (DS).METHODSThis study was limited to patients who were treated with 2-level PLIF for 2-level DS at L3–4-5. Between 2005 and 2014, 33 patients who could be followed up for at least 2 years were included in this study. The average age at the time of surgery was 72 years, and the average follow-up period was 5.6 years. Based on clinical assessments, the Japanese Orthopaedic Association (JOA) score and recovery rate were evaluated. The patients were divided into 2 groups based on the recovery rate: the good outcome group (G group; n = 19), with recovery rate ≥ 50%, and the poor outcome group (P group; n = 14) with recovery rate < 50%. Spinopelvic parameters were measured using lateral standing radiographs of the whole spine as follows: sagittal vertical axis (SVA), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), and segmental lordosis (SL) at L3–4-5. The clinical outcomes and radiological parameters were assessed preoperatively and at the final follow-up. Radiological parameters were compared between the 2 groups.RESULTSThe mean JOA score improved significantly in all patients from 10.8 points before surgery to 19.6 points at the latest follow-up (mean recovery rate 47.7%). For radiological outcomes, no difference was observed from preoperative assessment to final follow-up in any of the spinopelvic parameters except SVA. Although no significant difference between the 2 groups was detected in any of the spinopelvic parameters, there were significant differences in the change in SL and LL (ΔSL 3.7° vs −2.1° and ΔLL 1.2° vs −5.6° for the G and P groups, respectively). In addition, the number of patients in the G group was significantly larger for the patients with ΔSL-plus than those with ΔSL-minus (p = 0.008).CONCLUSIONSThe clinical outcomes of 2-level PLIF for 2-level DS limited at L3–4-5 appeared to be satisfactory. The results indicate that acquisition of increased SL in surgery might lead to better clinical outcomes.

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Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion with Endoscopic Disc Drilling Preparation Technique for Symptomatic Foraminal Stenosis Secondary to Severe Collapsed Disc Space: A Clinical and Computer Tomographic Study with Technical Note

Brain Sciences ◽

10.3390/brainsci10060373 ◽

2020 ◽

Vol 10 (6) ◽

pp. 373 ◽

Cited By ~ 5

Author(s):

Pang Hung Wu ◽

Hyeun Sung Kim ◽

Yeon Jin Lee ◽

Dae Hwan Kim ◽

Jun Hyung Lee ◽

...

Keyword(s):

Computer Tomography ◽

Interbody Fusion ◽

Transforaminal Lumbar Interbody Fusion ◽

Disc Height ◽

Foraminal Stenosis ◽

Lumbar Interbody Fusion ◽

Disc Space ◽

Computer Tomographic ◽

Post Operation

Background: Severe collapsed disc secondary to degenerative spinal conditions leads to significant foraminal stenosis. We hypothesized that uniportal posterolateral transforaminal lumbar interbody fusion with endoscopic disc drilling technique could be safely applied to the collapsed disc space to improve patients’ pain score, restore disc height, and correct the segmental angular parameters. Methods: We included patients who met the indication criteria for lumbar fusion and underwent uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion with pre-operative Computer Tomography mid disc height of less than or equal to 5 mm and MRI of Grade 3 Foraminal Stenosis. Visual analogue scale and computer tomography pre-operative and post-operative sagittal disc height in the anterior, middle and posterior part of the disc; sagittal focal segmental angle; mid coronal disc height and coronal wedge angles were evaluated. Results: 30 levels of Endo-TLIF were included, with a mean follow up of 12 months. The mean improvement in decreasing pain score was 2.5 ± 1.1, 3.2 ± 0.9 and 4.3 ± 1.0 at 1 week post operation, 3 months post operation and at final follow up, respectively, p < 0.05. There was significant increase in mid sagittal computer tomographic anterior, middle and posterior disc height of 6.99 ± 2.30, 6.28 ± 1.44, 5.12 ± 1.79 mm respectively, p < 0.05. CT mid coronal disc height showed an increase of 7.13 ± 1.90 mm, p < 0.05. There was a significant improvement in the CT coronal wedge angle of 2.35 ± 4.73 and the CT segmental focal sagittal angle of 1.98 ± 4.69, p < 0.05. Conclusion: Application of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion in patients with severe foraminal stenosis secondary to severe collapsed disc space significantly relieved patients’ pain and restored disc height without early subsidence or exiting nerve root dysesthesia in our cohort of patients.

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Anterior Lumbar Interbody Fusion (ALIF): Technique Video: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opaa132 ◽

2020 ◽

Vol 19 (4) ◽

pp. E404-E404 ◽

Cited By ~ 1

Author(s):

Pingguo Duan ◽

Jeremy M V Guinn ◽

Brenton Pennicooke ◽

Ratnesh N Mehra ◽

Chih-Chang Chang ◽

...

Keyword(s):

Surface Area ◽

Interbody Fusion ◽

Ventral Surface ◽

Surgical Anatomy ◽

Anterior Lumbar Interbody Fusion ◽

Direct Access ◽

Lumbar Interbody Fusion ◽

Disc Space ◽

Implant Size ◽

Segmental Lordosis

Abstract This surgical video demonstrates the technique of an anterior lumbar interbody fusion (ALIF). This video demonstrates the surgical approach, technical nuances of ALIF, and pearls. The main surgical anatomy and approach-related risks are discussed. The video demonstrates the nuances of ALIF, discussing the importance of the release of the disc space to allow for height restoration and lordosis, endplate preparation to enhance arthrodesis, and choice of implant size. The incision is made via a left paramedian approach with a retroperitoneal dissection and mobilization of the vasculature for access to the disc space. The ALIF provides direct access to the ventral surface of the exposed disc, allowing for an incision of the anterior longitudinal ligament, bilateral release of the annulus fibrosus, and access to a large surface area of the vertebral endplate. This anterior access allows for the placement of implants with a greater surface area for fusion, and this facilitates restoration of segmental lordosis, disc height improvement, and foraminal height increase. We have received informed consent from this patient for the video of this case.

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Disc Height Restoration after Transforaminal Lumbar Interbody Fusion: Is There a Correlation with Clinical Outcomes?

The Spine Journal ◽

10.1016/j.spinee.2010.07.300 ◽

2010 ◽

Vol 10 (9) ◽

pp. S114 ◽

Cited By ~ 1

Author(s):

Jennifer Kaur R. Sohal ◽

Steven D. Glassman ◽

Robert J. Woodruff ◽

Leah Y. Carreon

Keyword(s):

Clinical Outcomes ◽

Interbody Fusion ◽

Transforaminal Lumbar Interbody Fusion ◽

Disc Height ◽

Lumbar Interbody Fusion

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Unilateral transforaminal lumbar interbody fusion and bilateral anterior-column fixation with two Brantigan I/F cages per level: clinical outcomes during a minimum 2-year follow-up period

Journal of Neurosurgery Spine ◽

10.3171/spi.2006.4.3.198 ◽

2006 ◽

Vol 4 (3) ◽

pp. 198-205 ◽

Cited By ~ 38

Author(s):

Hiroshi Taneichi ◽

Kota Suda ◽

Tomomichi Kajino ◽

Akira Matsumura ◽

Hiroshi Moridaira ◽

...

Keyword(s):

Clinical Outcomes ◽

Interbody Fusion ◽

Japanese Orthopaedic Association ◽

Posterior Lumbar Interbody Fusion ◽

Transforaminal Lumbar Interbody Fusion ◽

Anterior Column ◽

Lumbar Interbody Fusion ◽

Anterior Column Support ◽

The Mean

Object There are no published reports of unilateral transforaminal lumbar interbody fusion (TLIF) in which two Brantigan I/F cages were placed per level through a single portal to achieve bilateral anterior-column support. The authors describe such a surgical technique and evaluate the clinical outcomes of this procedure. Methods Data obtained in 86 (93.5%) of the first 92 consecutive patients who underwent the procedure were retrospectively reviewed; the minimum follow-up duration was 2 years. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scoring system. Disc height, disc angle, cage positioning in the axial plane, and fusion status were radiographically evaluated. The mean follow-up period was 33.8 months. The mean improvement in the JOA score was 77.2%. Fusion was successful in 93% of the cases. According to the Farfan method, the mean anterior and posterior disc heights increased from 20.2 and 16.9% preoperatively to 35.9 and 22.7% at follow up, respectively (p < 0.01). The mean disc angle increased from 4.8° preoperatively to 7.5° at last follow-up examination (p < 0.01). Two cages were correctly placed to achieve bilateral anterior-column support in greater than 85% of the cases. The following complications occurred: hardware migration in two patients and deep infection cured by intravenous antibiotic therapy in one patient. Conclusions Unilateral TLIF involving the placement of two Brantigan cages per level led to good clinical results. Two Brantigan cages were adequately placed via a single portal, and reliable bilateral anterior-column support was achieved. Although the less invasive unilateral approach was used, the outcomes were as good as those in many reported series of posterior lumbar interbody fusion in which the Brantigan cages were placed via the bilateral approach.

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Anterior lumbar compared to oblique lumbar interbody approaches for multilevel fusions to the sacrum in adults with spinal deformity and degeneration

Journal of Neurosurgery Spine ◽

10.3171/2020.4.spine20198 ◽

2020 ◽

Vol 33 (4) ◽

pp. 461-470

Author(s):

Zhuo Xi ◽

Dean Chou ◽

Praveen V. Mummaneni ◽

Huibing Ruan ◽

Charles Eichler ◽

...

Keyword(s):

Spinal Deformity ◽

Interbody Fusion ◽

Adult Spinal Deformity ◽

Disc Height ◽

Lumbar Interbody Fusion ◽

Significant Difference ◽

Height Change ◽

The Mean ◽

Segmental Lordosis ◽

Lateral Interbody

OBJECTIVEIn adult spinal deformity and degenerative conditions of the spine, interbody fusion to the sacrum often is performed to enhance arthrodesis, induce lordosis, and alleviate stenosis. Anterior lumbar interbody fusion (ALIF) has traditionally been performed, but minimally invasive oblique lumbar interbody fusion (OLIF) may or may not cause less morbidity because less retraction of the abdominal viscera is required. The authors evaluated whether there was a difference between the results of ALIF and OLIF in multilevel anterior or lateral interbody fusion to the sacrum.METHODSPatients from 2013 to 2018 who underwent multilevel ALIF or OLIF to the sacrum were retrospectively studied. Inclusion criteria were adult spinal deformity or degenerative pathology and multilevel ALIF or OLIF to the sacrum. Demographic, implant, perioperative, and radiographic variables were collected. Statistical calculations were performed for significant differences.RESULTSData from a total of 127 patients were analyzed (66 OLIF patients and 61 ALIF patients). The mean follow-up times were 27.21 (ALIF) and 24.11 (OLIF) months. The mean surgical time was 251.48 minutes for ALIF patients and 234.48 minutes for OLIF patients (p = 0.154). The mean hospital stay was 7.79 days for ALIF patients and 7.02 days for OLIF patients (p = 0.159). The mean time to being able to eat solid food was 4.03 days for ALIF patients and 1.30 days for OLIF patients (p < 0.001). After excluding patients who had undergone L5–S1 posterior column osteotomy, 54 ALIF patients and 41 OLIF patients were analyzed for L5–S1 radiographic changes. The mean cage height was 14.94 mm for ALIF patients and 13.56 mm for OLIF patients (p = 0.001), and the mean cage lordosis was 15.87° in the ALIF group and 16.81° in the OLIF group (p = 0.278). The mean increases in anterior disc height were 7.34 mm and 4.72 mm for the ALIF and OLIF groups, respectively (p = 0.001), and the mean increases in posterior disc height were 3.35 mm and 1.24 mm (p < 0.001), respectively. The mean change in L5–S1 lordosis was 4.33° for ALIF patients and 4.59° for OLIF patients (p = 0.829).CONCLUSIONSPatients who underwent multilevel OLIF and ALIF to the sacrum had comparable operative times. OLIF was associated with a quicker ileus recovery and less blood loss. At L5–S1, ALIF allowed larger cages to be placed, resulting in a greater disc height change, but there was no significant difference in L5–S1 segmental lordosis.

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

Neurosurgery ◽

10.1093/neuros/nyz310_336 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Cited By ~ 1

Author(s):

Zhuo Xi ◽

Shane Burch ◽

Chih-Chang Chang ◽

Hui-bing Ruan ◽

Charles M Eichler ◽

...

Keyword(s):

Blood Loss ◽

Interbody Fusion ◽

Anterior Lumbar Interbody Fusion ◽

Disc Height ◽

Lumbar Interbody Fusion ◽

Lateral Interbody Fusion ◽

Height Increase ◽

Segmental Lordosis ◽

Oblique Lateral Interbody Fusion ◽

Lateral Interbody

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 < .001). The average blood loss was 214 ml for ALIF and 74 ml for OLIF (P < .001). The average day to solid food was 2.55 for ALIF and 0.8 for OLIF (P < .001). The average cage height was 14.78 mm for ALIF and 12.9 mm (P < .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.

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