Category: Spine

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Development and internal validation of a risk score for subsidence of expandable spacers in transforaminal lumbar interbody fusion (TLIF) surgery

Brain and Spine 5 (2025) 104322

This study developed and internally validated the Expandable TLIF Subsidence Index (ETSI) to predict risk of cage subsidence after TLIF surgery with expandable spacers. Key risk factors include high ASA score, non-degenerative indication, lower lumbar levels, small cage size, and posterior cage position.

• A risk score (Expandable TLIF Subsidence Index, ETSI) was developed to predict cage subsidence (CS) after transforaminal lumbar interbody fusion (TLIF) using expandable spacers.

• The study analyzed 388 patients (482 levels), finding a 31.7% CS rate at 3 months.

• Independent risk factors for CS included high ASA score, non-degenerative surgical indication, lower lumbar level, small cage size, and posterior cage position.

• The ETSI score ranges from -2 to 6; higher scores indicate higher CS risk (each point increases CS odds by about 2x).

• Modifiable risk factors (cage size and position) can reduce CS risk if addressed during surgery.

• Higher ETSI scores are also associated with increased risk of non-union/pseudarthrosis.

• The ETSI demonstrated moderate predictive performance (AUROC ≈ 0.68).

• The score may aid surgical planning and should be externally validated in future studies.

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Cervical deformity correction: comparison of neurological, radiographic, and patient-reported outcome measures by three-column osteotomy level

J Neurosurg Spine 43:433–442, 2025

Three-column osteotomy (3CO) for cervical deformity at C7–T1 is linked to higher neurological deficits, less radiographic correction, and worse Neck Disability Index outcomes compared to T2–6 levels. Surgeons should prefer 3CO below T1 when feasible for better neurological and functional results.

• Study compared outcomes of three-column osteotomy (3CO) for cervical deformity at C7–T1 vs T2–6 levels.

• Patients with 3CO at C7–T1 had higher rates of new postoperative neurological deficits (56% vs 18%).

• T2–6 3CO resulted in greater radiographic correction (T1 slope and C2–T4 SVA) than C7–T1 3CO.

• Neck Disability Index (NDI) improved after T2–6 3CO but worsened after C7–T1 3CO at 1 year.

• All patients with neurological deficits had at least partial recovery; 20% achieved complete recovery.

• 3CO level selection is multifactorial, but caudal to T1 is recommended when feasible due to better outcomes.

• Study limitations include retrospective design and single-institution data.

• Largest study to date comparing neurological, radiographic, and patient-reported outcomes by 3CO level.

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Risk Factors of 90-Day Unplanned Readmission After Lumbar Spine Surgery for Degenerative Lumbar Disk Disease: A Systematic Review and Meta-Analysis

Neurosurgery 97:908–916, 2025

This meta-analysis identified a 7.72% 90-day unplanned readmission rate after lumbar spine surgery. Significant risk factors include older age, higher BMI, depression, diabetes, hypertension, renal failure, and ASA grade >2. Enhanced preoperative optimization and targeted strategies for high-risk patients are recommended to reduce readmissions.

• A meta-analysis of 11 studies (648,415 patients) found a 7.72% incidence of unplanned 90-day readmission after lumbar spine surgery.

• Significant risk factors for readmission include older age, higher body mass index (BMI), depression, diabetes mellitus (DM), hypertension (HTN), renal failure, and an American Society of Anesthesiologists (ASA) grade greater than 2.

• Surgical factors such as fusion and laminectomy were not significantly associated with readmission.

• Main causes for readmission included wound infection, wound dehiscence, and implant failure; disk reherniation was the leading cause at 90 days.

• Enhanced preoperative optimization and careful patient selection are recommended, especially for elderly and high-comorbidity patients.

• Targeted preventive strategies may reduce readmissions and improve healthcare resource utilization.

• Limitations include retrospective study designs and insufficient data on some perioperative risk factors.

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Evaluation of Discrepancy Between Radiographic Success and Patient Satisfaction in Adult Spinal Deformity Surgery

Neurosurgery 97:821–828, 2025

Despite radiographic success in adult spinal deformity surgery, 24.1% of patients remained dissatisfied, mainly due to postoperative lumbar stiffness-related disability. Satisfaction was not linked to radiographic parameters but was independently predicted by the modified lumbar stiffness disability index, highlighting the importance of counseling patients about this trade-off.

• About 24.1% of patients were dissatisfied with adult spinal deformity (ASD) surgery despite radiographic success.

• Radiographic success was defined as optimal alignment, no mechanical complications, and no revision surgery.

• Patient satisfaction was measured using SRS-22; scores <4.0 indicated less satisfaction.

• Clinical outcomes (pain, disability, quality of life) improved after surgery, but lumbar stiffness (M-LSDI) worsened.

• No significant differences in radiographic parameters were found between satisfied and less satisfied groups.

• High postoperative lumbar stiffness (M-LSDI score) was the single independent risk factor for dissatisfaction.

• Longer fusion length was associated with higher lumbar stiffness and lower satisfaction.

• Patients should be informed about the trade-off between pain relief and increased lumbar stiffness before surgery.

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Intraoperative vancomycin for preventing infection after open spine surgery: a systematic review and meta-analysis of randomized controlled trials

J Neurosurg Spine 43:509–518, 2025

A meta-analysis of seven randomized controlled trials found that intraoperative vancomycin use in open spine surgery did not significantly reduce rates of superficial or deep surgical site infections. Further large-scale studies are needed to clarify its efficacy and inform clinical guidelines.

• A systematic review and meta-analysis of 7 randomized controlled trials (RCTs) with 2235 patients assessed the efficacy of intraoperative vancomycin in preventing infections after open spine surgery.

• No significant reduction in overall surgical site infections (SSI), deep infections, or superficial infections was found with intraoperative vancomycin compared to control.

• Subgroup analyses showed no benefit in either instrumented or uninstrumented spine surgeries.

• There was no significant shift toward gram-negative or culture-negative infections with vancomycin use.

• Potential risks include local cytotoxicity and possible impairment of bone healing and spinal fusion.

• Current evidence is limited by small sample sizes, heterogeneity in vancomycin administration, and variable follow-up durations.

• The study concludes intraoperative vancomycin may not reduce infection risk and further large RCTs are warranted.

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Which interbody device minimized nonunion, subsidence, and reoperation after anterior cervical discectomy and fusion?

J Neurosurg Spine 43:453–463, 2024

This meta-analysis found that allograft spacers in anterior cervical discectomy and fusion (ACDF) result in lower nonunion and revision rates compared to PEEK cages, with no significant difference in subsidence risk. Allograft offers enhanced fusion and minimizes revision without increasing subsidence.

• Allograft and PEEK cages are the most commonly used interbody spacers in anterior cervical discectomy and fusion (ACDF), replacing autograft due to lower donor site morbidity.

• This meta-analysis included 10 studies with 1462 patients comparing allograft and PEEK cages for ACDF, analyzing nonunion, subsidence, and reoperation rates.

• Allograft showed a significantly lower rate of nonunion than PEEK cages (OR 0.33, p = 0.01), indicating better fusion outcomes.

• Reoperation due to nonunion was significantly higher with PEEK cages compared to allograft (OR 0.28, p < 0.01), but overall reoperation rates for any cause were not significantly different.

• No significant difference was found in the incidence or amount of subsidence between allograft and PEEK cages.

• Allograft’s osteoconductive properties likely contribute to its higher fusion rate, while PEEK cages may lead to fibrous interface formation, reducing solid fusion.

• Meta-regression showed no significant effect of smoking, age, or number of fused levels on nonunion rates.

• Conclusion: Allograft is advantageous over PEEK cages in ACDF due to higher fusion rates and lower revision risk, without increasing subsidence

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Surgical outcomes for spinal arachnoid cysts and webs: a case series

Acta Neurochirurgica (2025) 167:248

This retrospective case series found that surgical treatment for spinal arachnoid cysts (SAC) and webs (SAW) resulted in favorable outcomes (mMC I-II) in 90% and 83% of patients, respectively, with low complication and recurrence rates. Surgery should be considered for symptomatic patients.

• Spinal arachnoid cysts (SAC) and spinal arachnoid webs (SAW) are rare intradural pathologies causing pain and myelopathic symptoms.

• MRI is the main diagnostic tool, but distinguishing between SAC and SAW can be difficult; both may show the “scalpel sign”.

• This retrospective study reviewed 35 patients (29 SAC, 6 SAW) treated surgically from 2011–2023.

• Most patients presented with pain, gait disturbance, sensory, or motor deficits; preoperative neurological status was often not severe.

• Surgical treatment (fenestration or resection) led to favorable outcomes (mMC I-II) in 90% of SAC and 83% of SAW patients.

• Complications occurred in 14.7% of SAC cases but resolved without lasting deficits; no complications in SAW group.

• Recurrence was rare (2.7% in SAC, none in SAW) during short-term follow-up.

• Surgery is recommended for symptomatic patients, with generally favorable short-term results, but larger and longer-term studies are needed.

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Does Anterior Lumbar Interbody Fusion Reduce Mechanical Complication and Pseudarthrosis Rate at the Lumbosacral Junction in Adult Spinal Deformity Surgery in Comparison to Posterior Lumbar Interbody Fusion?

Int J Spine Surg 2025, 19 (4) 409-417

In adult spinal deformity surgery, anterior lumbar interbody fusion (ALIF) at the lumbosacral junction significantly reduces mechanical complications, pseudarthrosis, and reoperation rates compared to posterior lumbar interbody fusion (PLIF), suggesting ALIF should be preferred unless direct posterior decompression is necessary.

• ALIF (anterior lumbar interbody fusion) at the lumbosacral junction significantly reduces mechanical complications and pseudarthrosis rates compared to PLIF (posterior lumbar interbody fusion) in adult spinal deformity (ASD) surgery.

• ALIF is associated with lower rates of implant-related pain and reoperation than PLIF.

• PLIF is an independent risk factor for mechanical complications in long-segment ASD constructs.

• ALIF results in significantly less blood loss, fewer transfusions, and shorter ICU and hospital stays than PLIF.

• ALIF provides superior biomechanical stability and fusion rates, likely due to better endplate preparation and larger cage footprint.

• PLIF remains suitable for cases requiring direct neural decompression, such as severe stenosis or spondylolisthesis.

• Surgical technique selection should consider patient anatomy, surgical goals, and specific pathology at the lumbosacral junction.

• Study limitations include retrospective design, single-center data, and potential selection bias; further multicenter studies are needed.

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The First Grade III Lumbar Spondylolisthesis Treated With the Novel 360° Artificial Disc/Artificial Facet Replacement Solution

Int J Spine Surg 2025, 19 (4) 362-369

This case report describes the first use of a combined 360° motion-preserving surgery—utilizing Prodisc L Artificial Disc and TOPS facet replacement—for grade III lumbar spondylolisthesis, showing rapid pain relief, improved function, and high patient satisfaction, suggesting a potential alternative to spinal fusion for select patients.

• First reported case of grade III lumbar spondylolisthesis treated with a novel 360° motion-preserving solution combining Prodisc L Artificial Disc Replacement and the Premia TOPS System.

• Traditional treatment is spinal fusion, but it reduces motion and can cause adjacent segment disease, especially problematic for younger, active patients.

• The patient, a 36-year-old man with progressive L5-S1 grade III spondylolisthesis and severe disc collapse, had failed conservative therapy and declined fusion.

• Surgery was performed in two stages: anterior artificial disc replacement, followed by posterior facet replacement with the TOPS device.

• Significant improvements were seen in pain, function, and satisfaction, with the patient pain-free and highly satisfied by 3 and 9 months post-op.

• This case suggests the 360° arthroplasty approach may offer a motion-preserving alternative to fusion for high-grade spondylolisthesis.

• Further research and long-term data are needed to confirm safety, durability, and broader effectiveness.

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Comparison of outcomes after anterior versus posterior surgery for degenerative cervical myelopathy

The Spine Journal 25 (2025) 1964−1973

This pooled analysis of 980 DCM patients found that anterior surgical decompression led to greater improvements in quality of life and disability at 1 year compared to posterior surgery, especially in mild cases. Anterior surgery had higher dysphagia risk; posterior surgery had more wound infections and pseudoarthrosis.

• Anterior surgical decompression for degenerative cervical myelopathy (DCM) leads to greater improvements in 1-year patient-reported quality of life and disability compared to posterior decompression.

• The benefit of anterior surgery is especially pronounced in patients with mild DCM, with significantly better outcomes in physical function, disability, and functional status.

• Improvements with anterior surgery are mainly driven by reductions in pain and enhanced ability to engage in recreational and physical activities.

• Dysphagia is more common after anterior surgery, while pseudoarthrosis and wound infections are more frequent after posterior surgery.

• No significant differences were found between the two approaches in mental health outcomes or overall neurological improvement as measured by mJOA and SF36-MCS.

• The study pooled data from three large, prospective multicenter clinical trials, analyzing 980 surgical patients with DCM.

• Results were robust across multiple sensitivity analyses and consistent with recent real-world and meta-analytic studies.

• The findings help inform surgical decision-making but do not dictate a single preferred approach for all patients.

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Spinal Cord Tract Integrity in Degenerative Cervical Myelopathy

Neurosurgery 97:681–690, 2025

This study used diffusion tensor imaging to assess spinal cord tract integrity in degenerative cervical myelopathy (DCM). Significant injury was found in the lateral corticospinal tract, fasciculus gracilis, and fasciculus cuneatus, suggesting these are key tracts affected in DCM, while other tracts may support compensatory recovery.

• Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction, often resulting in persistent motor deficits despite surgery.

• This study used diffusion tensor imaging (DTI) and atlas-based analysis to assess specific spinal cord tract integrity in DCM patients versus healthy controls.

• Fractional anisotropy (FA) was significantly reduced in the lateral corticospinal tract, fasciculus gracilis, and fasciculus cuneatus in DCM patients compared to healthy volunteers.

• No significant FA differences were found between mild and moderate-to-severe DCM patients for any tract.

• Most other spinal tracts, including reticulospinal and rubrospinal, showed no significant FA changes, suggesting possible preservation and compensatory potential.

• Limitations include small sample size, age differences between groups, and inability to analyze tracts at the site of maximal compression.

• Findings suggest injury to specific tracts in DCM, with other tracts as potential targets for future therapies and compensatory recovery.

• Further studies with larger cohorts and improved imaging are needed to validate and expand these results.

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Less is more: complication rates and outcome measures of intradiscal osteotomy versus pedicle subtraction osteotomy in adult spinal deformity

J Neurosurg Spine 43:313–323, 2025

In adults with spinal deformity, intradiscal osteotomy (IDO) is as effective as pedicle subtraction osteotomy (PSO) for lordosis restoration and sagittal balance, with similar complication rates but significantly less blood loss, shorter operative time, and less postoperative back pain at 3 months.

• Intradiscal osteotomy (IDO) and pedicle subtraction osteotomy (PSO) are both used to correct adult spinal deformity, aiming to restore lumbar lordosis and sagittal balance.

• IDO and PSO showed similar fusion rates and complication profiles, with no statistically significant difference in rates of proximal junctional kyphosis, hardware failure, DVT, wound infection, or pseudarthrosis.

• IDO resulted in significantly less estimated blood loss (800 ml vs. 1400 ml) and shorter operative time (7 vs. 8.5 hours) compared to PSO.

• IDO patients reported less back pain at 3 months post-op (VAS 1 vs. 3, p=0.01) than PSO patients.

• Both techniques effectively restored lumbar lordosis, but IDO achieved better postoperative sagittal vertical axis (SVA) correction (5 cm vs. 7 cm, p=0.01).

• Higher BMI was a significant risk factor for postoperative complications in both groups.

• IDO is less technically complex, preserves vertebral body integrity, and is more familiar to spine surgeons than PSO.

• IDO can be considered an effective and potentially safer alternative to PSO for selected adult spinal deformity patients.

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Outcomes After Decompression Only Versus Decompression and Fusion for Lumbar Facet Cysts: A Systematic Review and Meta-Analysis

Neurosurgery 97:536–544, 2025

This meta-analysis compared decompression only (DO) versus decompression and fusion (DF) for lumbar facet cysts. DF reduced cyst recurrence and improved back pain resolution but had longer hospital stays. Reoperation and radiculopathy resolution rates were similar between groups. Most studies lacked standardized criteria for choosing DF over DO.

• Lumbar facet cysts (LFCs) are associated with facet degeneration and segmental instability; surgical management is debated between decompression only (DO) and decompression with fusion (DF).

• This systematic review and meta-analysis included 9 comparative studies with 3393 patients (DO: 1940, DF: 1453).

• Spondylolisthesis rates were significantly higher in the DF group (65.8% vs 24.3% in DO).

• DO had higher odds of cyst recurrence (6.3% vs 0%) and lower odds of back pain resolution (56.6% vs 74.5%) compared to DF.

• Reoperation rates (DO 7.2%, DF 5.9%) and radiculopathy resolution (DO 77.3%, DF 87.2%) were similar between groups.

• Length of hospital stay was shorter in the DO group.

• Criteria for choosing DF vs DO varied and were often not clearly defined across studies.

• The study concludes DF reduces cyst recurrence and improves back pain resolution but has longer hospital stays; reoperation and radiculopathy outcomes are comparable.

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Does Transforaminal Endoscopic Lumbar Discectomy Provide More Value than Microdiscectomy?

Operative Neurosurgery 29:209–218, 2025

Microdiscectomy (MD) provided greater value than transforaminal endoscopic discectomy (TED) for lumbar disc herniations at this institution, with higher improvement in patient-reported outcomes per dollar spent and shorter operative times. TED had higher costs and a steeper learning curve, but similar reoperation rates.

• This study compares the value of transforaminal endoscopic lumbar discectomy (TED) and microdiscectomy (MD) for lumbar disc herniation using a novel Operative Value Index (OVI).

• OVI measures percent change in Oswestry Disability Index (ODI) per $1000 spent intraoperatively, integrating patient outcomes and time-driven activity-based costing.

• MD had a significantly higher OVI, lower operative times, and lower intraoperative costs than TED; no significant difference in length of stay or reoperation rates was found.

• Only 43.5% of TED cases achieved clinically important improvement (MCID), compared to 66.3% for MD.

• TED was mainly used for foraminal herniations and had a higher proportion of older patients and comorbidities.

• Longer OR setup times and higher costs for TED may relate to the learning curve and surgeon experience.

• Authors suggest OVI is a practical, real-time value metric but note limitations including small TED sample size and retrospective design.

• Future studies should assess long-term outcomes, total episode costs, and track OVI as surgeons gain TED experience.

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The role of XLIF in spinal revision surgery involving failed interbody implants

Acta Neurochirurgica (2025) 167:221

This review evaluates the use of Extreme Lateral Interbody Fusion (XLIF) for removing failed spinal implants. XLIF offers advantages over traditional approaches, including reduced operative risk, blood loss, and hospital stay, but requires surgical expertise due to potential nerve and vascular complications.

• XLIF (Extreme Lateral Interbody Fusion) is increasingly used for spinal revision surgery to remove failed interbody implants and other foreign bodies.

• A systematic literature review identified only a few published cases (seven documented, four included) using XLIF for this purpose.

• XLIF offers advantages over anterior and posterior approaches, including reduced operative time, less blood loss, shorter hospital stays, and safer navigation around scar tissue and neurovascular structures.

• The technique allows for insertion of larger interbody cages, improving spinal stability and fusion outcomes.

• Most reported complications are minor and transient, such as temporary nerve injury, but careful patient selection and surgical expertise are required.

• XLIF is especially valuable in complex revision cases where traditional approaches pose higher risks due to scar tissue or anatomical challenges.

• Current evidence is limited to case reports and small series; more robust studies are needed to validate safety and efficacy.

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Anatomy of the superior hypogastric plexus and its relevance to anterior lumbar interbody fusion

J Neurosurg Spine 43:19–25, 2025

This cadaveric study details the anatomy of the superior hypogastric plexus (SHP) at L5–S1, its variations, and implications for anterior lumbar interbody fusion (ALIF). The authors recommend left-sided SHP retraction to minimize nerve injury and retrograde ejaculation; if unfeasible, midline splitting and lateral mobilization are advised.

• The study examined the anatomy of the superior hypogastric plexus (SHP) at the L5–S1 level and its relevance to anterior lumbar interbody fusion (ALIF) surgery.

• Injury to the SHP during ALIF can cause retrograde ejaculation (RE) in males and sexual dysfunction in females.

• The SHP typically overlays the midline at L5–S1 with a slight leftward shift and is covered by connective tissue beneath the peritoneum.

• Three morphological types of SHP were found: single cord, plexiform, and fiber; the plexus divides into hypogastric nerves below the aortic bifurcation.

• Retraction of the SHP to the left side is generally more feasible (up to 15.3 mm) than to the right (up to 5.3 mm); left-sided retraction is recommended.

• If left retraction is not possible, splitting the SHP at the midline and retracting both components laterally is advised.

• Careful SHP mobilization and avoidance of electrocautery are crucial to reduce risk of RE and sexual dysfunction in ALIF patients.

• The findings highlight the importance of detailed SHP anatomy knowledge for safer ALIF, especially with minimally invasive approaches.

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A survival analysis for predictors of implant subsidence following 1- or 2-level transforaminal lumbar interbody fusion

J Neurosurg Spine 43:42–51, 2025

This study found that after 1- or 2-level TLIF, aggressive disc height restoration and taller interbody implants significantly increase the risk of implant subsidence, especially in patients with poor bone quality. Surgeons should balance correction goals with subsidence risk, particularly in those with low Hounsfield unit measurements.

• This study analyzed predictors of interbody implant subsidence after 1- or 2-level transforaminal lumbar interbody fusion (TLIF) using a time-to-event (survival) analysis.

• Aggressive disc height restoration and use of taller interbody implants significantly increased the risk of subsidence.

• Poor baseline bone quality, measured by lower Hounsfield units (HU) on CT, was a strong independent predictor for significant (≥4 mm) subsidence.

• Longer fusion constructs (more instrumented levels) also increased the risk of significant subsidence.

• No significant association was found between cage material (titanium vs PEEK), device geometry, or lumbopelvic parameters and subsidence risk.

• Subsidence occurred in 38.2% of levels (≥2 mm) and significant subsidence in 10.4% (≥4 mm) by last follow-up.

• Clinical implications suggest balancing correction goals with subsidence risk, especially in patients with poor bone quality.

• Further multicenter and prospective studies are recommended to validate these findings.

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Segmental and overall lumbar lordosis after single-level minimally invasive transforaminal lumbar interbody fusion: a systematic review and meta-analysis

J Neurosurg Spine 43:70–82, 2025

This systematic review and meta-analysis found that single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) generally preserves segmental and overall lumbar lordosis, with preoperative alignment and use of expandable cages predicting postoperative lordosis. Greater segmental lordosis improvement was associated with reduced leg pain, but clinical outcome correlations were otherwise limited.

• Single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) generally preserves or slightly increases segmental and overall lumbar lordosis.

• Meta-analysis of 35 studies (1935 patients) showed significant but modest increases in segmental lordosis (mean +2.2°) and lumbar lordosis (mean +2.8°) postoperatively.

• Preoperative alignment and use of expandable cages are significant predictors of postoperative lordosis change.

• Greater improvement in segmental lordosis was associated with larger reductions in postoperative leg pain, but no strong correlation with other clinical outcomes was found.

• Most included studies were retrospective case series, with high heterogeneity in surgical technique and reporting.

• No significant association was found between facetectomy type, operative bed, or fixation technique and changes in lordosis.

• The main goal of MI-TLIF is neural decompression and fusion, not alignment correction; alternative approaches may be needed for major lordosis restoration.

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Development and internal validation of a risk score for subsidence of expandable spacers in transforaminal lumbar interbody fusion (TLIF) surgery

Brain and Spine 5 (2025) 104322

This study developed and validated the Expandable TLIF Subsidence Index (ETSI) to predict risk of cage subsidence after TLIF surgery with expandable spacers. Key risk factors include high ASA score, non-degenerative indications, lower lumbar level, small cage size, and posterior cage position. Some risk factors are modifiable.

• A risk score (ETSI) was developed to predict cage subsidence (CS) after TLIF surgery using expandable spacers.

• Independent risk factors for CS include high ASA score, non-degenerative surgical indication, lower lumbar level, small cage size, and posterior cage position.

• ETSI ranges from -2 to 6 points and shows a moderate ability to classify CS risk (AUROC ≈ 0.68).

• Modifiable risk factors (cage size and position) can reduce CS risk if optimized by the surgeon.

• Higher ETSI scores are associated with increased risk of non-union/pseudarthrosis at 3 and 12 months.

• Anterior placement of the cage lowers subsidence risk, while posterior placement increases it.

• The study included 388 patients with a 3-month CS rate of 31.7%.

• The ETSI is the first comprehensive scoring system for CS risk with expandable TLIF cages.

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