Comparison of Complication Rates Between Transforaminal Interbody Fusion and Anteroposterior Fusion for One- or Two-Level Degenerative Lumbar Spine Surgery: A Propensity Score Matched Analysis.

Introduction Although transforaminal interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) combined with posterior fusion (AP) have similar fusion rates, it is unclear if choice of approach has an impact on post-operative complications. Research question Is the incidence of residual leg and/or back pain requiring additional treatment after one- or two-level TLIF and AP similar? Material and methods Adult patients who underwent one- or two-level TLIF or AP for degenerative pathology were identified and matched using age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA), insurance status, smoking status, revision and number of levels fused. The incidence of radicular leg and back pain requiring emergency department visit/readmission or same level surgical intervention was compared between the two groups. Results Of the 319 TLIF and 288 AP cases, 119 cases in each cohort were matched. TLIF patients had shorter operative times (203 min vs 258 min, P<0.001) and hospital stays than the AP patients (3.76 days vs 4.98 days, P<0.001). The incidence of residual leg pain (7 vs 5, P=0.769) and back pain (13 vs 15, P=0.841) was similar between the two groups. Except for constipation, which was more common in the AP group, the incidence of complications was similar between the two groups. Conclusions Patients undergoing one- or two-level TLIF showed shorter operative time and hospital stay compared with those undergoing AP. The incidence of leg radiculopathy and back pain was similar between the two groups. Surgeons should consider these findings as part of the decision-making process regarding which approach to use in patients requiring a lumbar interbody fusion.

Biomechanical effects of a novel standalone posterior lumbar facet joint stabilization device: an in vitro cadaveric study.

OBJECTIVE: Although pedicle screw-rod (PSR) instrumentation remains the gold standard, it has complications, including pedicle breach and facet joint violation. There is current interest in facet joint stabilization with the potential to create a less invasive, natural arch of fixation that may avoid the complications of PSR instrumentation. This study examined the stabilizing potential of a novel facet joint fixation device for single-level (L4-L5) fixation in a human cadaveric model. METHODS: Six L3-S1 specimens were tested multidirectionally under pure moment loading (7.5 Nm) in 3 conditions: 1) intact, 2) L4-L5 facet fixation without screws, and 3) L4-L5 facet fixation with screws. L4-L5 intervertebral disc angles were measured radiographically. Range of motion (ROM) and disc angles were compared using repeated-measures analysis of variance analysis, with statistical significance p<0.05. RESULTS: Compared to the intact condition, L4-L5 bilateral facet fixation without or with screw fixation significantly reduced L4-L5 angular ROM in all directions (p≤0.003). No significant differences were observed in cranial and caudal adjacent-segment ROM (p≥0.08) except for L3-L4 fixation in extension, which exhibited small motion increases (0.12° without screws, 0.1° with screws) versus the intact condition (p≤0.003). No statistically significant differences were observed in disc angle values between the conditions (p=0.87). CONCLUSIONS: Bilateral lumbar facet fixation with and without supplemental transfacet screw fixation provided significant stability. Cranial and caudal adjacent-level ROM was not influenced by facet fixation except for a slight increase in cranial segment motion during extension. Facet fixation did not alter the lordotic intervertebral disc angle at the instrumented level.

Does Surgical Day of Week Affect Patient Outcomes and Hospital Costs Following Lumbar Fusion?

Background As the population ages, surgical intervention for degenerative spine conditions is increasing, and this causes a commiserate increase in healthcare expenditures associated with these procedures. Little research has been done on the effect of early-week versus later-week surgeries on patient outcomes, cost, and length of stay (LOS) in patients undergoing lumbar fusion surgery. The purpose of this study is to compare LOS, patient outcomes, and hospital costs between patients having surgery early in the week and later in the week. Methods A retrospective review of 771 patients undergoing a one-, two-, or three-level lumbar fusion from December 2020 to December 2023 at a single institution was performed. Demographics, surgical details, postoperative outcomes and cost were compared between patients who had surgery on Monday, Tuesday, and Wednesday, to those having surgery Thursday or Friday. Univariate and multivariate analyses were performed to compare the groups. Results There were no differences in age, sex, BMI, race, American Society of Anesthesiology (ASA) scores, Charlson Comorbidity Index (CCI) scores, number of operative levels or inpatient/outpatient status between early- and late-week surgeries. Postoperatively the only significant difference was cost, late-week surgeries were, on average, $3,697 more expensive than early-week surgeries ($26,506 vs. $22,809; p<0.001). On multivariate analysis late-week surgeries were 2.47 times more likely to have a non-home discharge (OR: 2.47, 95% CI: 1.24 to 4.95; p=0.010) and 2.19 times more likely to have a 30-day readmission (OR: 2.19, 95% CI:1.01 to 4.74; p=0.044) Additionally, late-week surgeries were $2,041.55 (ß:2,041.55, 95% CI: 804.72 to 3,278.38; p=0.001) more expensive than early-week surgeries. Conclusions At our institution, patients undergoing one- to three-level lumbar fusion surgery on Thursday or Friday had a higher risk of non-home discharge, 30-day readmission, and incurred higher cost than those having early-week surgery. Further research is needed to elucidate the reasons for these findings and to evaluate interventions aimed at improving outcomes for patients undergoing surgery later in the week.

Patient of Congenital Absence of a Lumbar Pedicle With Nerve Root Anomaly Presenting With Ipsilateral Foraminal Stenosis by Vertebral Fracture.

Background: Patients with congenital absence of a lumbar pedicle and nerve root anomaly presenting with ipsilateral foraminal stenosis are extremely rare. Case Presentation: An 80-year-old man had low back and right thigh pain. Radiographs and computed tomography (CT) showed L3 vertebral body fracture and the absence of the right L3 lumbar pedicle. He was diagnosed with L2-L3 right foraminal stenosis caused by an L3 vertebral fracture and underwent lumbar fusion at L2-L3 and L3-L4. Intraoperatively, we confirmed that an anomalous nerve root was divided from the right L2 nerve root near the dorsal root ganglion (DRG). Conclusions: Patients with congenital absence of a lumbar pedicle are less prone to ipsilateral foraminal stenosis because they theoretically have a large space in the foramen. This rare case was caused because of additional instability due to vertebral fracture under the condition of a nerve root anomaly and lumbar degeneration.

An evaluation of fusion status following lumbar fusion surgery utilizing multi-planar computed tomography.

PURPOSE: To report the rate of fusion in a sample of patients undergoing lumbar fusion surgery and assess interrater reliability of computed tomography (CT)-based parameters for the assessment of fusion. METHODS: All adult patients who underwent lumbar fusion surgery from 2017 to 2021 were retrospectively identified. Patient demographics and surgical characteristics were collected through chart review of the electronic medical records. CT scans were reviewed independently by two attending spine surgeons and two spine fellows. Fusion was defined as evidence of bone bridging in any one of (1) posterolateral gutters, (2) facets, or (3) interbody (when applicable) on any CT views. Evidence of screw haloing was indicative of nonunion. Interrater reliability was determined using cohen's kappa. Afterwards, a consensus agreement for each component of fusion was reached between participants. RESULTS: The overall fusion rate among all procedures was 63/69 (91.3%). Overall 22/25 (88.0%) TLIF, 16/19 (84.2%) PLDF, 3/3 (100%) LLIF, and 22/22 (100%) circumferential fusions experienced a successful fusion. Interrater reliability was good for interbody fusion (k = 0.734) and moderate for all other measures (k = 0.561 for posterolateral fusion; k = 0.471 for facet fusion; k = 0.458 for screw haloing). Overall, interrater reliability as to whether a patient had a fusion or nonunion was moderate (k = 0.510). CONCLUSION: There was only moderate interrater reliability across most radiographic measures used in assessing lumbar fusion status. Reliability was highest when evaluating the presence of interbody fusion. The majority of fusions occurred across the facet joints.

The Impact of Improved Compliance With Enhanced Recovery After Surgery on Frail Patients Undergoing Multi-Level Posterior Lumbar Fusion Surgery for Degenerative Lumbar Diseases.

Background: Patients with frailty are more prone to have perioperative adverse events, and enhanced recovery after surgery (ERAS) has been widely adopted to improve perioperative outcomes. The purpose of this study was to assess the impact of improved compliance with ERAS on perioperative outcomes in frail patients. Methods: Geriatric patients (over 65 years) who underwent multi-level lumbar fusion surgery between June 2017 and June 2022 were included. The patients were divided into two groups according to their degree of compliance with the ERAS. Stepwise nearest-neighbor propensity score matching 1:1 cohorts for age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classfication and Charlson Comorbidity Index (CCI) was performed between groups, namely frail-compliant (FC), frail-noncompliant (FN). Further length of stay (LOS), complications and clinical efficacy were compared between groups. Results: There were 83 pairs of well-balanced patients with comparable clinical baseline data. It was worth noting that patients in FC group has significant lower overall complications (20.5% in the FC group vs 39.8% in the FN group, P = 0.007), major complications (7.2% in the FC group vs 19.3% in the FN group, P = 0.022) and shorter LOS (11.18 ± 5.32 in the FC group vs 14.45 ± 4.68 in the FN group, P < 0.001) than patients in FN group. In addition, the initial occurrence of ambulation (2.14 ± 1.21 in FC group vs 3.18 ± 1.73 in FN group, P = 0.012) and bowel movement (3.68 ± 1.24 in FC group vs 4.17 ± 1.32 in FN group, P = 0.031) were earlier for patients in FC group than patients in FN group. With regard to clinical efficacy, there were no significant difference between FC and FN group in terms of patients who meet minimal clinical important difference (MCID) for Oswestry Disability Index (ODI) at postoperative day (POD) 30, Visual Analog Scale (VAS) for back at POD 30-90 and VAS for legs at POD 30, 90, and 180 follow-up intervals. However, there were significant more patients meeting MCID for ODI at POD 90 and180, and VAS for back at POD 180 between FC and FN group. Conclusions: In this retrospective cohort study, we found that frail patients with higher ERAS adherence group had a lower incidence of overall complication, mjor complications, and a shorter LOS than their lower ERAS adherence counterparts. In addition, frail patients with higher ERAS adherence had earlier ambulatioin and bowel movement. More importantly, we found there were significant more patients meeting MCID for ODI at POD 90 and180, and VAS for back at POD 180 in higher ERAS adherence than their lower counterparts.

Predictability in Achieving Target Intervertebral Lordosis Using Personalized Interbody Implants.

BACKGROUND: Lumbar lordosis distribution has become a pivotal factor in re-establishing the foundational alignment of the lumbar spine. This can directly influence overall sagittal alignment, leading to improved long-term outcomes for patients. Despite the wide availability of hyperlordotic stock cages intended to achieve optimal postoperative alignment, there is a lack of correlation between the lordotic shape of a cage and the resultant intervertebral alignment. Recently, personalized spine surgery has witnessed significant advancements, including 3D-printed personalized interbody implants, which are customized to the surgeon's treatment and alignment goals. This study evaluates the reliability of 3D-printed patient-specific interbody implants to achieve the planned postoperative intervertebral alignment. METHODS: This is a retrospective study of 217 patients with spinal deformity or degenerative conditions. Patients were included if they received 3D-printed personalized interbody implants. The desired intervertebral lordosis (IVL) angle was prescribed into the device design for each personalized interbody (IVL goal). Standing postoperative radiographs were measured, and the IVL offset was calculated as IVL achieved minus IVL goal. RESULTS: In this patient population, 365 personalized interbodies were implanted, including 145 anterior lumbar interbody fusions (ALIFs), 99 lateral lumbar interbody fusions (LLIFs), and 121 transforaminal lumbar interbody fusions. Among the 365 treated levels, IVL offset was 1.1° ± 4.4° (mean ± SD). IVL was achieved within 5° of the plan in 299 levels (81.9%). IVL offset depended on the approach of the lumbar interbody fusion and was achieved within 5° for 85.9% of LLIF, 82.6% of transforaminal lumbar interbody fusions and 78.6% of ALIFs. Ten levels (2.7%) missed the planned IVL by >10°. ALIF and LLIF levels in which the plan was missed by more than 5° tended to be overcorrected. CONCLUSIONS: This study supports the use of 3D-printed personalized interbody implants to achieve planned sagittal intervertebral alignment. CLINICAL RELEVANCE: Personalized interbody implants can consistently achieve IVL goals and potentially impact foundational lumbar alignment.

Changes in Alignment at Untreated Vertebral Levels Following Short-Segment Fusion Using Personalized Interbody Cages: Leveraging Personalized Medicine to Reduce the Risk of Reoperation.

BACKGROUND: An abnormal postoperative lordosis distribution index (LDI), which quantifies the ratio between the lordosis at L4 to S1 and the lordosis at L1 to S1, contributes to the development of adjacent segment disease and increased revision rates in patients undergoing short-segment lumbar intervertebral fusions. Incorporating preoperative spinopelvic parameters and LDI into the surgical plan for short-segment fusion is important for guiding alignment restoration and preserving normal preoperative alignment in unfused segments. This study examined changes in LDI, segmental lordosis, and lordosis of the unfused levels in patients treated with personalized interbody cage (PIC) implants. METHODS: This retrospective study evaluated radiographic measurements from 111 consecutively treated patients diagnosed with degenerative spinal conditions and treated with a short-segment fusion of L4 to L5, L5 to S1, or L4 to S1 using PIC implant(s) within 6 months of the fusion procedure. Comparisons of intervertebral lordosis for treated and untreated levels as well as LDI pre- and postoperatively were performed. RESULTS: In patients with a preoperative hypolordotic distribution (LDI < 50%), statistically significant increases were found in LDI postoperatively, approaching the normal LDI range (LDI 50%-80%). Likewise, patients with hyperlordotic distribution preoperatively (LDI > 80%) experienced a decrease in LDI postoperatively, trending toward the normal range, although the changes were not statistically significant. Intervertebral lordosis for the L5 to S1 level increased significantly following the placement of a PIC in the normal and hypolordotic LDI groups. Changes in intervertebral lordosis for L5 to S1 were not significant for patients with preoperative hyperlordotic LDI. Reciprocal changes in intervertebral lordosis at L1 to L4 were not observed in any groups. CONCLUSIONS: PIC implants may provide a benefit for patients, particularly those with hypolordotic distributions preoperatively. They have the potential to further improve patient outcomes by helping surgeons to achieve patient-specific lordosis goals, which may help to reduce the risk of adjacent segment disease and revisions in patients undergoing short-segment lumbar intervertebral fusions. CLINICAL RELEVANCE: Personalized implants can help surgeons achieve patient-specific alignment goals, potentially prevent adjacent segment disease, and reduce long-term reinterventions.

Radiological Evaluation of Lumbar Endplate Dimensions in the Indian Population and Their Correlation With Cage Placement/Length in Diverse Lumbar Fusion Techniques.

Background Lumbar fusion techniques are vital for treating various spinal conditions by promoting vertebral fusion to alleviate pain and restore stability. Given the anatomical uniqueness of the Indian skeletal structure, this study evaluates the radiological dimensions of lumbar endplates in the Indian population and their correlation with the placement and length of interbody cages used in various lumbar fusion techniques such as oblique lateral lumbar interbody fusion (OLIF), transforaminal lumbar interbody fusion (TLIF), and anterior lumbar interbody fusion (ALIF). This study aimed to conduct radiological measurements of lumbar endplates in the Indian population and correlate them with cage placement and length in lumbar fusion techniques. Methods This prospective study was conducted at the orthopaedic ward of a tertiary care center in Western Maharashtra, India. Healthy individuals (aged >18 years, either gender) selected with a 95% confidence level using Philip Core Integrity software (Amsterdam, Netherlands) were included in the study. We excluded those with a history of low back pain, previous lumbar spine surgeries, fractures, tuberculosis, tumors, deformities, degenerative diseases, or lesions affecting the lumbar spine. Quantitative measurements such as oblique and sagittal diameters, apophyseal ring widths, and interbody cage lengths were calculated using multiplanar reformatting with specific imaging parameters. Results A total of 150 individuals with an average age of 39.83 ± 14.17 years, ranging from 20 to 65 years. Among the study population, 68 were males and 82 were females. Among the male study population, oblique parameters such as Angle AOB and Mid-OD (oblique diameter) show considerable variability, with Angle AOB ranging from 51.43 ± 2.40 mm (L2 inferior) to 31.59 ± 4.25 mm (L5 inferior) and Mid-OD ranging from 41.59 ± 2.59 mm (L3 superior) to 34.38 ± 2.26 mm (S1 superior). Side-sagittal dimensions vary from 32.11 ± 2.50 mm (S1 superior) to 36.48 ±3.26 mm (L3 superior), emphasizing the need for tailored surgical planning. In contrast, females in the study population exhibit distinct anatomical profiles, with Angle AOB ranging from 52.15 ± 2.43 mm (L2 inferior) to 20.45 ± 5.45 mm (S1 superior) and Mid-OD from 33.48 ± 2.15 mm (L3 inferior) to 42.45 ± 2.59 mm (L3 superior). These findings underscore gender-specific anatomical differences crucial for individualized clinical evaluation and treatment strategies. Conclusion This study comprehensively analyzes oblique, side-sagittal, transverse, and midsagittal anatomic parameters across various vertebral levels in men and women, highlighting significant anatomical variations crucial for clinical assessments and surgical interventions.

Are the Clinical Outcomes and Cost-Effectiveness of Robot-Assisted Pedicle Screw Placement in Lumbar Fusion Surgery Superior to Computed Tomography Navigation and Freehand Fluoroscopy-Guided Techniques? A Systematic Review and Network Meta-Analysis.

OBJECTIVE: Spinal fusion surgery is known to be an expensive intervention. Although innovative technologies in the field aim at improving operative efficiency and outcomes, total costs must be considered. The authors hope to elucidate any differences between robot-assisted (RA) and computed tomography navigation (CT-nav) or freehand fluoroscopy-guided (FFG) pedicle screw placement in relation to patient outcomes and cost-effectiveness in lumbar fusion surgery (LFS). METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the authors performed a systematic review to identify studies comparing clinical outcomes between CT-nav or RA versus FFG in LFS patients. All included studies utilized bilateral pedicle screws. Statistical analysis was performed using R. RESULTS: Of the 1162 identified studies, 5 were included in the analysis. Direct evidence showed that RA decreased hospital length of stay when compared to FFG (mean difference [MD]: -2.67 days; 95% confidence interval [CI]: -4.25 to -1.08; P < 0.01). Indirect evidence showed that RA decreased operative time when compared to CT-nav (MD: -65.57 minutes; 95% CI: -127.7 to -3.44; P < 0.05). For estimated blood loss, direct evidence showed that RA was superior to FFG (MD: -120.62 mL; 95% CI: -206.39 to -34.86; P < 0.01). However, no significant difference was found between RA and CT-nav for estimated blood loss (MD: 14.88 mL; 95% CI: -105.54 to 135.3; P > 0.05). There were no other significant differences in Oswestry Disability Index, visual analog scale, or complication or reoperation rates between RA and FFG or CT-nav. CONCLUSIONS: This study shows that RA pedicle screw placement in LFS provides similar patient outcomes to CT-nav and FFG. Robot-assisted operations were found to give rise to cost savings via decreased length of stay when compared to both CT-nav and FFG techniques. Cost-savings of $4086-$4865/patient and $7317-$9654/patient could be achieved when utilizing RA over CT-nav and FFG, respectively. However, extra upfront and maintenance costs may impact full adoption of RA in LFS.

Predictors of postoperative persistent low back pain following lumbar fusion in patients older than 75 years: An analysis of a minimum 2-year follow-up.

PURPOSE: This study aimed to evaluate pre- and perioperative predictors associated with persistent low back pain (LBP) following lumbar fusion in patients aged > 75 years. METHODS: This single-center retrospective study examined 310 patients aged > 75 years who underwent lumbar fusion for lumbar degenerative disease (104 males, 206 females; mean age, 79 [75-90] years). The visual analog scale (VAS) score for LBP was examined preoperatively and 2-year postoperatively. The persistent LBP group comprised patients with a 2-year postoperative LBP-VAS score ≥ 3. The demographic and preoperative radiographic parameters were also reviewed. A multivariate stepwise logistic regression analysis was performed of variables with values of P < 0.2 on the univariate analysis. RESULTS: Ninety-nine patients (32%) experienced persistent postoperative LBP. Multivariate logistic regression analysis revealed that age < 82 years, history of previous lumbar decompression, and greater preoperative VAS score for LBP were associated with greater postoperative persistent LBP after lumbar fusion, whereas other factors, such as gender, body mass index, osteoporosis, diabetes mellitus, depression, symptom duration, operative time, estimated blood loss, and spinopelvic sagittal parameters, were not. CONCLUSIONS: This study showed that a relatively younger age, history of preoperative lumbar decompression, and greater preoperative VAS score for LBP were preoperative predictors of postoperative persistent LBP following lumbar fusion in elderly patients. In contrast, preoperative spinopelvic sagittal parameters were not associated with persistent postoperative LBP. Although lumbar fusion is expected to improve LBP, surgeons should pay attention to age, surgical history, and preoperative back pain intensity.

Can titanium surface technology reduce cost for biologics in anterior lumbar interbody fusion?

OBJECTIVE: Advances in surface architecture and technology have made interbody fusion devices more bioactive, with the hope of facilitating the fusion process more successfully. The advent of these increasingly bioactive implants may reduce reliance on more expensive biologics that have previously been used to achieve high fusion rates. METHODS: A retrospective review of prospectively collected data (August 2018-December 2019) was conducted of consecutively performed anterior lumbar interbody fusions in which an acid-etched, nanosurface-modulated, titanium interbody device packed only with corticocancellous allograft chips and local blood was used. Minimum follow-up was 1 year, and inclusion required available imaging and outcome metrics preoperatively and at 1 year. Fusion and subsidence were assessed via CT scans and/or dynamic radiographs. Health-related quality-of-life measures (Oswestry Disability Index [ODI], visual analog scale [VAS] back/leg) were collected pre- and postoperatively. RESULTS: In total, 55 patients met inclusion criteria (1 year of follow-up, available imaging, and outcome metrics). A total of 69 lumbar levels were treated in these 55 patients. The mean age was 67 ± 12.1 years, with 47% female patients. Roughly one-third (35%) had previous spine surgery, and approximately one-tenth (9.1%) had prior spinal fusion. A total of 20.6% were treated at multiple levels (mean levels per patient 1.2, minimum 1, maximum 3). The mean preoperative patient-reported outcomes were as follows: ODI 39.71 ± 18.15, VAS back 6.49 ± 2.19, and VAS leg 5.41 ± 2.71. One year after surgery, the mean improvements in patient-reported outcomes (vs preoperative scores) were as follows: ODI -22.9 ± 13.08 (p < 0.001), VAS back -3.75 ± 2.03 (p < 0.001), VAS leg -3.73 ± 2.32 (p < 0.001). All levels achieved fusion at 1 year postoperatively based on CT scans (65/69 levels) or dynamic radiographs (4/69 levels, change in score < 5% on flexion-extension radiographs). Four of the 65 levels were assigned to the grade 3 category according to a CT-based grading system, meaning cranial and caudal endplate bone apposition to the implant on both surfaces with no clear intervertebral bone connection through or around the implant. Sixty-one of 65 were found to have contiguous intervertebral bone bridging and thus were assigned to grade 1 (n = 54) or grade 2 (n = 7). Low-grade graft subsidence (Marchi grade 0 or I) occurred in 9 levels (13.0%) and high-grade subsidence (Marchi grade II or III) in 4 levels (5.8%). No patients required reoperation at the level of anterior lumbar interbody fusion and no radiographic or clinical evidence of pedicle screw loosening or failure was observed. CONCLUSIONS: The combination of advances in materials science and surface technology as demonstrated with a nanotechnology titanium cage resulted in the ability to obtain lumbar interbody fusion with allograft chips and local blood alone. Achieving high fusion rates with low-cost biologics/allograft provides for an attractive pathway toward reducing the cost of reconstructive spine care, and a potential incremental benefit for healthcare economics.

Screw Stimulation Thresholds for Neuromonitoring in Minimally Invasive Oblique Lateral Lumbar Interbody Fusion (OLLIF): A Correlational Study.

INTRODUCTION: This study presents findings from an investigation into the correlation of neuromonitoring techniques in minimally invasive lumbar fusions and their open counterparts regarding acceptable thresholds for screw stimulation. The threshold for acceptable stimulation value for open surgery has been established. The study compared acceptable thresholds for open pedicle screws where there is more connection between the screw and the soft tissue. METHODS: The neuromonitoring data of 17 patients who underwent oblique lateral lumbar interbody fusion (OLLIF) procedures between September 2023 to May 2024 were reviewed. Neuromonitoring was conducted throughout surgeries, recording stimulation thresholds for pedicle screws insulated and uninsulated, to simulate the environment of a screw during open and minimally invasive surgery respectively. Patients' BMI was also collected for potential correlation analysis. RESULTS: Results indicate a discernible correlation between stimulation thresholds in open and minimally invasive surgeries, but no definitive correlation with BMI due to sample size limitations. Though a significant correlation between the two stimulating styles is apparent, there is a good correlation to suggest what threshold should determine a standard stimulation threshold for minimally invasive surgeries. CONCLUSION: The study emphasizes the need for refined neuromonitoring strategies in minimally invasive spinal fusion (MISF) surgeries to ensure patient safety and surgical effectiveness. Further research with larger cohorts is recommended to establish optimized protocols that have a clearly defined amplitude for MISF thresholds.

Use of the "Two-Three Click" Protocol in Screw Stabilization of a Patient With Loosened Nuts and Dislocation of Rods - A Case Report.

Vertebral fixation, utilizing titanium screws, is a highly prevalent technique employed to address spinal instability. Screw stabilization malfunction due to pedicle screw nuts loosening is rare. Under tightening the internal nut in the pedicle screw head may increase the likelihood of rod movement within the system resulting in severe pain when moving. Our goal is to raise the attention of surgeons when tightening the screws nuts of the screw stabilization because the consequences for the patient can be subsequent additional operations and complications.  This report describes a clinical case of a 40-year-old man who underwent three surgeries at different clinics several years ago for disc herniation at the L4-L5 level and screw stabilization at the same level. The patient presents to the neurosurgery clinic of Saint Marina University Hospital with a clinical manifestation of low back pain escalating with movement, with a pain intensity rating of six on the Visual Analogue Scale (VAS). From the CT scan, it was revealed a malfunction in the screw stabilization with loosening of the screw nuts and dislodgement of the rods. Screw stabilization was restored using intraoperative X-ray guidance and following the "two-three click" protocol. The patient was mobilized on the first day after surgery and discharged on the fifth day with neurological improvement (VAS=1). The patient was followed up for a period of six months, and no further complications were observed. Surgeons must use caution while tightening the screw nuts, as not doing so may result in additional surgeries and complications for the patient in the future. The "two-three click" protocol for screw stabilization is an effective method for minimizing the issues associated with inner loosening and rod migration.

High Lumbar Spinal Fusion Rates Using Cellular Bone Allograft Irrespective of Surgical Approach.

BACKGROUND: Mounting evidence demonstrates a promising safety and efficacy profile for spinal fusion procedures using cellular bone allograft (CBA). However, limited data exists on fusion outcomes stratified by surgical approach. The current study investigates the effectiveness of CBA in lumbar spinal fusion by surgical approach (ie, anterior, lateral, and posterior approaches). METHODS: Patients undergoing lumbar spinal fusion with CBA (Trinity Elite) were enrolled into a prospective, multi-center, open-label clinical study (NCT02969616). Fusion status was assessed by an independent review of dynamic radiographs and computed tomography images. Clinical outcome measures included quality of life (QoL; EQ5D), disability (Oswestry Disability Index [ODI]), and pain (visual analog scale [VAS]) for back pain and leg pain). Patient data extending to 24 months were analyzed in a post-hoc analysis. RESULTS: A total of 252 patients underwent interbody fusion (159 women; 93 men). Patients had a mean age of 58.3 years (SD 12.5), height of 168.3 cm (SD 10.2), and weight of 87.3 kg (SD 20.0) with a body mass index of 30.8 kg/m2 (SD 6.5). At 12 months, the overall fusion success rate for bridging bone was 98.5%; fusion success was 98.1%, 100.0%, and 97.9% for anterior, lateral, and posterior approaches, respectively. At 24 months, the overall fusion success rate for bridging bone was 98.9%; fusion success was 97.9%, 100.0%, and 98.8% for anterior, lateral, and posterior approaches, respectively. The surgical approach did not significantly impact fusion success. A significant (P < 0.0001) improvement in QoL, pain, and disability scores was also observed. Significant differences in the ODI, VAS, and EQ5D were observed between the treatment groups (P < 0.05). CONCLUSIONS: CBA represents an attractive alternative to autograft alone, reporting a high rate of successful fusion and clinical outcomes across various surgical approaches. CLINICAL RELEVANCE: The use of CBA for spinal fusion procedures, regardless of surgical approach, provides high rates of fusion with a favorable safety profile and improved patient outcomes. TRIAL REGISTRATION: NCT02969616.

Lumbar Fusions in Patients with Sickle Cell Disease: A Propensity-Matched Analysis of Postoperative Complications.

OBJECTIVE: The present study compares postoperative outcomes between patients with and without sickle cell disease (SCD) undergoing 1-to 3-level lumbar spinal fusion for degenerative pathologies. METHODS: Patients who underwent 1-to 3-level lumbar spinal fusion for degenerative pathologies from 2010 to 2021 were identified using the PearlDiver database. Patients were separated into 1) SCD and 2) non-SCD groups and were propensity-matched 1:1 for age, sex, Elixhauser Comorbidity Index, surgical approach, and various comorbidities. Complications were separately analyzed by single- and multilevel procedures using chi-squared and Mann-Whitney U testing. RESULTS: Propensity-score matching identified 1934 SCD and non-SCD patients who underwent single-level fusion and 2094 SCD and non-SCD patients who underwent multilevel fusion. Across single-level fusions, those with SCD had a significantly higher risk of neurovascular compromise (P < 0.001), venous thromboembolism (P = 0.004), pneumonia (P = 0.032), urinary tract infections (P = 0.001), and greater postoperative opioid usage out to 12 months (P = 0.018). Across multilevel fusions, SCD carried higher risk for neurovascular compromise (P < 0.001), pneumonia (P = 0.010), and urinary tract infections (P < 0.001). All SCD patients had significantly higher opioid use at 1 month (P = 0.001) and at 6 months (P = 0.009) postoperatively. CONCLUSIONS: Patients with SCD undergoing lumbar spinal fusion demonstrate higher risks for coagulopathic, ischemic, and infectious-related complications, as well as long-term postoperative opioid use. Awareness of the unique complication profile in SCD patients may help guide surgeons in refining perioperative management strategies to optimize outcomes in patients with SCD.

The effect of chronic kidney disease on short-term single-level lumbar fusion outcomes.

INTRODUCTION: Chronic kidney disease (CKD) has an increasing global prevalence and has previously been associated with increased complications and morbidity after spine surgery. Understanding the isolated effect of CKD on short-term patient outcomes is critical for optimizing perioperative risk management and healthcare utilization. OBJECTIVE: The aim of this study is to utilize coarsened exact matching (CEM) to analyze the isolated effect of CKD on short-term patient outcomes in single-level posterior lumbar fusion surgery. METHODS: A retrospective analysis of 4680 consecutive patients undergoing single-level, posterior-only lumbar fusion was performed. Univariate logistic regression comparing the odds of outcomes in patients with CKD (n=40) to patients without medical comorbidities (n=2329) was performed. CEM was then employed to match patients with CKD to those without any comorbidities 1:1 on ten patient characteristics known to affect neurosurgical outcomes. Primary outcomes included intraoperative complications, length of stay, discharge disposition, and 30-day Emergency Department (ED) visits, readmissions, reoperations, and mortality. RESULTS: In a univariate logistic regression, CKD was associated with increased risk of 30-day ED visits (OR=3.53, p=0.003) but not complication, discharge disposition, or 30-day readmissions or reoperations. Between otherwise exactly matched patients (n=72), CKD similarly remained associated with an increased risk of 30-day ED visits (OR=7.00, p=0.034) and not with other outcomes. CONCLUSION: Between otherwise exactly matched patients undergoing single-level posterior lumbar fusion, CKD was related to increased risk of 30-day ED utilization but not other markers indicative of inferior surgical outcomes. Further study must investigate the reasons for increased ED visitation and implement risk-mitigation strategies for these patients.

A comparative cohort study of surgical approaches for adult spinal deformity at a minimum 2-year follow-up.

STUDY DESIGN: This study was a retrospective multi-center comparative cohort study. MATERIALS AND METHODS: A retrospective institutional database of operative adult spinal deformity patients was utilized. All fusions > 5 vertebral levels and including the sacrum/pelvis were eligible for inclusion. Revisions, 3 column osteotomies, and patients with < 2-year clinical follow-up were excluded. Patients were separated into 3 groups based on surgical approach: 1) posterior spinal fusion without interbody (PSF), 2) PSF with interbody (PSF-IB), and 3) anteroposterior (AP) fusion (anterior lumbar interbody fusion or lateral lumbar interbody fusion with posterior screw fixation). Intraoperative, radiographic, and clinical outcomes, as well as complications, were compared between groups with ANOVA and χ2 tests. RESULTS: One-hundred and thirty-eight patients were included for study (PSF, n = 37; PSF-IB, n = 44; AP, n = 57). Intraoperatively, estimated blood loss was similar between groups (p = 0.171). However, the AP group had longer operative times (547.5 min) compared to PSF (385.1) and PSF-IB (370.7) (p < 0.001). Additionally, fusion length was shorter in PSF-IB (11.4) compared to AP (13.6) and PSF (12.9) (p = 0.004). There were no differences between the groups in terms of change in alignment from preoperative to 2 years postoperative. There were no differences in clinical outcomes. While postoperative complications were largely similar between groups, operative complications were higher in the AP group (31.6%) compared to the PSF (5.4%) and PSF-IB (9.1) groups (p < 0.001). CONCLUSION: While there were differences in intraoperative outcomes (operative time and fusion length), there were no differences in postoperative clinical or radiographic outcomes. AP fusion was associated with a higher rate of operative complications.

Effect of Residual Pain After Posterior Fusion Surgery for Lumbar Degenerative Disorders on Health-Related Quality of Life: A Two-Year Follow-Up Using Patient-Reported Outcome Measures.

STUDY DESIGN: This is a prospective cohort study. PURPOSE: The present study aimed to investigate the effects of residual pain after fusion surgery for lumbar degenerative diseases on quality of life (QOL). OVERVIEW OF LITERATURE: Residual symptoms after spinal surgery often restrict patients' activities of daily living and reduce their QOL. However, few studies have comprehensively addressed physical, psychological, and social factors. METHODS: The study population included a cohort of 208 patients (mean age: 67.9 years) who had undergone posterior interbody fusion for lumbar degenerative disease between 2012 and 2019. We asked the patients to complete the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Short Form Health Survey (SF-36) preoperatively, as well as at six, 12, and 24 months postoperatively. The presence of residual postoperative pain (RPP) was determined using the low back pain score of the JOABPEQ at six months postoperatively, and patients with an improvement of < 20 points compared to preoperative assessment were classified as RPP+ based on a previous study. RESULTS: In all patients, there was a notable postoperative improvement in all JOABPEQ and SF-36 domains compared to preoperative scores. The RPP+ group comprised 60 patients (69.6 years), while the RPP- group comprised 148 patients (67.2 years). In the RPP+ group, the lumbar function in the JOABPEQ and general health in the SF-36 showed limited postoperative enhancement. The pace of improvement in the role-emotional, role-physical, social functioning, vitality, and mental health scores was slower in the RPP+ group compared to the RPP- group. CONCLUSIONS: In the current study, we found that the presence of residual pain at six months postoperatively affected QOL improvement up to 24 months after surgery. Lingering postoperative pain substantially impacted functional incapacity, social engagement, and psychological well-being. Notably, the lumbar function in the JOABPEQ and general health in the SF-36 showed distinct progression patterns in the RPP+ group.

The influence of osteoporosis on mechanical complications in lumbar fusion surgery: a systematic review.

Background: Adults undergoing spine surgery often have underlying osteoporosis, which may be a risk factor for postoperative complications. Although these associations have been described, osteoporosis remains profoundly underdiagnosed and undertreated in the spine surgery population. A thorough, comprehensive systematic review summarizing the relationships between bone mineral density (BMD) and specific complications of lumbar fusion surgery could be a valuable resource for raising awareness and supporting clinical practice changes. Methods: PubMed, Embase, and Web of Science databases were searched for original clinical research articles reporting on BMD, or surrogate measure, as a predictor of complications in adults undergoing elective lumbar fusion for degenerative disease or deformity. Endpoints included cage subsidence, screw loosening, pseudarthrosis, vertebral fracture, junctional complications, and reoperation. Results: A total of 71 studies comprising 12,278 patients were included. Overall, considerable heterogeneity in study populations, methods of bone health assessment, and definition and evaluation of clinical endpoints precluded meta-analysis. Nevertheless, low BMD was associated with higher rates of implant failures like cage subsidence and screw loosening, which were often diagnosed with concomitant pseudarthrosis. Osteoporosis was also a significant risk factor for proximal junctional kyphosis, particularly due to fracture. Many studies found surgical site-specific BMD to best predict focal complications. Functional outcomes were inconsistently addressed. Conclusions: Our findings suggest osteoporosis is a significant risk factor for mechanical complications of lumbar fusion. These results emphasize the importance of preoperative osteoporosis screening, which allows for medical and surgical optimization of high-risk patients. This review also highlights current practical challenges facing bone health evaluation in patients undergoing elective surgery. Future prospective studies using standardized methods are necessary to strengthen existing evidence, identify optimal predictive thresholds, and establish specialty-specific practice guidelines. In the meantime, an awareness of the surgical implications of osteoporosis and utility of preoperative screening can provide for more informed, effective patient care.