Lumbar Interbody Fusion Surgery Research Articles

Impact of Osteoporosis on Short-Term Surgical Outcomes in Lumbar Degenerative Disease Patients Undergoing Lateral Lumbar Interbody Fusion: A Retrospective Analysis

This retrospective study assesses the influence of osteoporosis on the short-term clinical outcomes of lateral lumbar interbody fusion (LLIF) surgery in patients with lumbar degenerative diseases (LDD), focusing on complications, pain intensity, and quality of life improvements. The primary aim of this study is to investigate the impact of osteoporosis on the short-term clinical outcomes following LLIF surgery in LDD patients, with a particular focus on the incidence of cage subsidence (CS) and overall patient well-being postoperatively. A retrospective review was conducted on 73 patients who underwent LLIF for LDD. Patients were categorized into two groups based on osteoporosis status determined by dual-energy X-ray absorptiometry (DXA) scans: those with osteoporosis (n=20) and those without osteoporosis (n=53). Data collection included demographics, surgical details, complications, magnetic resonance imaging (MRI) analysis, pain intensity, and quality of life (Japanese Orthopaedic Association Back Pain Evaluation Questionnaire: JOABPEQ). The groups had no significant differences regarding operative time, estimated blood loss, and hospital stay duration. However, the incidence of CS was 40% in patients with osteoporosis, compared to 17% in non-osteoporotic patients. Despite this, significant improvements in spinal canal dimensions were observed in both groups. Both groups experienced significant reductions in pain intensity, with notable improvements in functional outcomes assessed by JOABPEQ, indicating the overall effectiveness of LLIF in enhancing patient well-being and functionality, irrespective of osteoporosis status. Osteoporosis increases the risk of CS in LLIF surgery for LDD patients but does not affect short-term pain relief and quality of life improvements.

Effects of Cage Implantation Depth on Sagittal Parameters and Functional Outcomes in Posterior Lumbar Interbody Fusion for the Treatment of L4-L5 Lumbar Degenerative Spondylolisthesis.

In the treatment of lumbar degenerative spondylolisthesis (LDS) with Posterior lumbar interbody fusion (PLIF) surgery, interbody fusion implants play a key role in supporting the vertebral body and facilitating fusion. The objective of this study was to assess the impact of implantation depth on sagittal parameters and functional outcomes in patients undergoing PLIF surgery. This study reviewed 128 patients with L4-L5 LDS between January 2016 and August 2019. All patients underwent an open PLIF surgery that included intravertebral decompression, implantation of pedicle screws and cage. We grouped according to the position of the center of the cage relative to the L5 vertebral endplate. Patients with the center of the cage located at the anterior 1/2 of the upper end plate of the L5 vertebral body were divided into Anterior group, and located at the posterior 1/2 of the upper end plate of the L5 vertebral body were divided into Posterior group. The lumbar lordosis (LL), segmental lordosis (SL), sacral slope (SS), pelvic incidence (PI), pelvic tilt (PT) and slope degree (SD) was measured for radiographic outcomes. We used the visual analog scale (VAS) and the oswestry disability index (ODI) score to assess functional outcomes. Paired t-test was used to compare imaging and bedside data before and after surgery between the two groups, and independent sample t-test, χ2 test and Fisher exact test were used to compare the data between the two groups. The mean follow-up of Anterior group was 44.13 ± 9.23 months, and Posterior group was 45.62 ± 10.29 months (P > 0.05). The LL, SL, PT, SS, SD and PI-LL after operation showed great improvements, relative to the corresponding preoperative values in both groups (P < 0.05). Compared to Posterior group, Anterior group exhibited far enhanced SL (15.49 ± 3.28 vs. 13.67 ± 2.53, P < 0.05), LL (53.47 ± 3.21 vs. 52.08 ± 3.15, P < 0.05) outcomes and showed depressed PI-LL (8.87 ± 5.05 vs. 10.73 ± 5.39, P < 0.05) outcomes at the final follow-up. Meanwhile, the SL in Anterior group (16.18 ± 3.99) 1 months after operation were also higher than in Posterior group (14.12 ± 3.57) (P < 0.05). We found that VAS and ODI at the final follow-up in Anterior group (3.62 ± 0.96, 25.19 ± 5.25) were significantly lower than those in Posterior group (4.12 ± 0.98, 27.68 ± 5.13) (P < 0.05). For patients with LDS, the anteriorly placed cage may provide better improvement of SL after PLIF surgery. Meanwhile, the anteriorly placed cage may achieve better sagittal parameters of LL and PI-LL and functional outcomes at the final follow-up.

Biphasic Calcium Phosphate Bone Graft With a Unique Surface Topography: A Single-Center Ambispective Study for Degenerative Disease of the Lumbar Spine.

This study is an ambispective evaluation and analysis of a single-center cohort. This study aimed to evaluate the performance of a novel biphasic calcium phosphate (BCP) bone graft with submicron-sized needle-shaped surface topography (BCP<µm) in interbody arthrodesis of the lumbar spine. This study was a single-center ambispective assessment of adult patients receiving BCP<µm as part of their lumbar interbody fusion surgery. The primary outcome was a fusion status on computed tomography (CT) 12months postoperative. The secondary outcomes included postoperative changes in the visual analogscale (VAS), Oswestry Disability Index (ODI), Short Form 12 (SF-12), and length of stay (LOS). Sixty-three patients with one- to three-level anterior (48, 76%) and lateral (15, 24%) interbody fusions with posterior instrumentation were analyzed. Thirty-one participants (49%) had three or more comorbidities, including heart disease (43 participants, 68%), obesity (31 participants, 49%), and previous lumbar surgery (23 participants, 37%). The mean ODI decreased by 24. The mean SF-12 physical health and SF-12 mental health improved by a mean of 11.5 and 6.3, respectively. The mean VAS for the left leg, right leg, and back improved by a mean of 25.75, 22.07, and 37.87, respectively. Of 101 levels, 91 (90%) demonstrated complete bridging trabecular bone fusion with no evidence of supplemental fixation failure. The data of BCP<µm in interbody fusions for degenerative disease of the lumbar spine provides evidence of fusion in a complicated cohort of patients.

Association between vertebral endplate defects and patient-reported symptoms: an immunohistochemical study investigating the COX-2/PGE-2/EP-4 axis

Background ContextVertebral endplate defects are often implicated in degenerative disc disorders, yet their connection to patient-reported symptoms remains unclear. COX-2 and PGE-2 are known for their roles in inflammation and pain, with EP-4 receptor involvement in pain signaling. Examining their expression in vertebral endplate tissues may provide insights into pathomechanism of low back pain. PurposeTo investigate the association between endplate defects and patient-reported symptoms and to further clarify the role of the COX-2/PGE-2/EP-4 axis in the pathogenesis of chronic low back pain. Study Design/SettingRetrospective study. Patient SampleA total of 71 patients who had undergone single-level L4/5 or L5/S1 modified laminectomy decompression preserving proximal upper laminae and transforaminal lumbar interbody fusion surgery were included in this study, including 18 patients diagnosed with lumbar disc herniation, 19 with lumbar disc herniation accompanied by degenerative lumbar spinal stenosis, and 34 with degenerative spondylolisthesis. Outcome MeasuresDemographic data, Pfirrmann grade, Modic changes, endplate defect score, visual analog scale (VAS) for back and leg pain, and Oswestry Disability Index (ODI) before surgery, 3-month and 6-month follow-up, and the percentage of immune-positive cells (COX-2, PGE-2, and EP-4) in endplate tissue sections. MethodsPatients were divided into defect and non-defect groups according to endplate morphology on lumbar MR. All intraoperative endplate specimens were immediately fixed in 10% formaldehyde, and then embedded in paraffin 3 days later for tissue sections. The outcome measures were compared between the defect group and non-defect group. Data were analyzed using independent t-tests and χ² tests. Pearson's rank correlation test was used to assess correlations between patient-reported symptoms and the percentage of immune-positive cells in the groups. Multivariable logistic regression models using the forward stepwise likelihood ratio method were used to identify the factors that were independently associated with endplate defects. ResultsThe age of Defect group was significantly higher than that of non-defect group (52.5±7.7 vs. 57.2±9.1. p=.024). There were no significant differences in gender, diagnosis, BMI, comorbidities, or surgical level between the two groups. Modic changes (Type Ⅱ/Type Ⅲ) were more common in patients of Defect group than non-defect group (38.5% vs. 11.1%, p<.001), and so was disc degeneration (Pfirrmann grade Ⅳ/Ⅴ) (69.2% vs. 33.3%, p<.001). Defect group had significantly higher VAS-Back (6.5±2.0 vs. 4.9±1.6, p<.001) and ODI scores (62.9±10.7 vs. 45.2±14.8, p<.001) than non-defect group, while there was no significant differences between the two groups during the 3 and 6-month follow-up after surgery. Histologically, Defect group was characterized by upregulation of COX-2, PGE-2, and EP-4 in endplate tissue sections. Both in defect and non-defect groups, VAS-Back showed moderate positive correlations with the expressions of COX-2 (r=0.643; r=0.558, p both<0.001), PGE-2 (r=0.611; r=0.640, p both<.001), and EP-4 (r=0.643; r=0.563, p both<.001). Multivariate regression analyses reveled that percentage of COX-2-positive cells was associated with endplate defects (OR=1.509, 95%CI [1.048–2.171], p=0.027), as well as percentage of PGE-2-positive (OR=1.291, 95%CI [1.106–1.508], p=.001) and EP-4-positive cells (OR=1.284, 95%CI [1.048∼2.171], p=.003). ConclusionsPatients with endplate defects had worse quality of life, more severe disc degeneration and Modic changes, and up-regulated COX-2/PGE-2/EP-4 axis expression in cartilage endplates in patients with defected endplates. Inflammatory factors may significantly contribute to the onset and progression of chronic low back pain in patients with endplate defects, consequently impacting patient-reported symptoms.

Development and validation of a nomogram to predict the risk of constipation after lumbar interbody fusion surgery.

To understand the incidence of postoperative constipation and the risk factors of constipation in patients with lumbar interbody fusion, we constructed and verified the constipation risk prediction model, so as to provide reference for the prevention and treatment of postoperative constipation. The data of patients undergoing lumbar interbody fusion in our hospital were retrospectively analyzed from December 2021 to December 2022. According to postoperative constipation, the patients were divided into constipation group and non-constipation group. Univariate logistic regression analysis and multivariate logistic regression analysis were used to determine independent risk factors for postoperative constipation. Based on independent risk factors, a nomogram was developed to predict the risk of constipation after lumbar interbody fusion. The prediction performance was assessed using receiver operating characteristic curve (ROC), calibration curve and decision curve analysis (DCA). Finally, bootstrapping method for internal validation was further evaluated the nomogram. A total of 282 patients participated in the study. 176 patients (62.41%) after lumbar interbody occurred constipation, and 106 patients were asymptomatic. Multivariate regression analysis showed independent risk factors, including the use of calcium channel blockers, polypharmacy, postoperative bed time, and constipation history. Multivariate regression analysis was used to establish the model. The C-index of the nomogram was 0.827 (95% CI 0.779-0.875), and the C-index of interval bootstrapping validation was 0.813 (95% CI 0.765-0.861), and the area under the AUC was 0.800. The nomogram showed good discrimination ability. The use of calcium channel blockers, polypharmacy, postoperative bed time, and history of constipation are independent risk factors for postoperative constipation in patients undergoing lumbar interbody fusion. The constructed risk prediction model has good discriminative ability.

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

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

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

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

Lateral-PLIF for spinal arthrodesis: concept, technique, results, complications, and outcomes.

Posterior lumbar interbody fusion (PLIF) surgery represents an effective option to treat degenerative conditions in the lumbar spine. To reduce the drawbacks of the classical technique, we developed a variant, so-called Lateral-PLIF, which we then evaluated through a prospective consecutive series of patients. All adult patients treated at our institute with single or double level Lateral-PLIF for lumbar degenerative disease from January to December 2017 were prospectively collected. Exclusion criteria were patients < 18years of age, traumatic patients, active infection, or malignancy, as well as unavailability of clinical and/or radiological follow-up data. The technique consists of insert the cages bilaterally through the transition zone between the central canal and the intervertebral foramen, just above the lateral recess. Pre- and postoperative (2years) questionnaires and phone interviews (4years) assessed pain and functional outcomes. Data related to the surgical procedure, postoperative complications, and radiological findings (1year) were collected. One hundred four patients were selected for the final analysis. The median age was 58years and primary symptoms were mechanical back pain (100, 96.1%) and/or radicular pain (73, 70.2%). We found a high fusion rate (95%). A statistically significant improvement in functional outcome was also noted (ODI p < 0.001, Roland-Morris score p < 0.001). Walking distance increased from 812m ± 543m to 3443m ± 712m (p < 0.001). Complications included dural tear (6.7%), infection/wound dehiscence (4.8%), and instrument failure (1.9%) but no neurological deterioration. Lateral-PLIF is a safe and effective technique for lumbar interbody fusion and may be considered for further comparative study validation with other techniques before extensive use to treat lumbar degenerative disease.

Impact of Obesity on Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgeries: A Systematic Review and Meta-Analysis

To evaluate the impact of obesity on various outcomes in patients undergoing minimally invasive transforaminal lumbar interbody fusion (TLIF) surgeries. PubMed, Scopus, Embase, and Cochrane Library databases were screened for studies reporting outcomes in obese and nonobese patients undergoing TLIF surgeries. Studies reporting operative time, estimated blood loss, length of hospital stay, incidence of pseudoarthrosis, Oswestry Disability Index (ODI) scores, pain scores (Visual Analog Scale, VAS), and PROMIS PF scores were included. A qualitative and quantitative analysis was performed to calculate mean differences or odds ratios (ORs) using random-effects models. Fourteen good-quality studies were included in this review, with a combined sample size of 4,889 participants. The analysis revealed that patients with obesity had slightly longer operative times compared to patients with normal weight, with a mean difference of 14.87minutes, though not significant. Similarly, morbidly obese patients had a mean difference of 21.44minutes in operative time. Estimated blood loss was comparable in both groups. However, morbidly obese patients had longer hospital stays, with a mean difference of 8.18days and obese patients have 20% higher odds of experiencing complications compared to nonobese patients. The incidence of pseudoarthrosis, ODI scores, or pain scores (VAS back and leg) were similar in obese and normal weight patients. Obesity, particularly morbid obesity, may have an impact on certain outcomes in patients undergoing minimally invasive TLIF surgeries. Morbidly obese patients tend to have significantly longer operative times with significantly longer hospital stays than nonobese patients.

Is it necessary to extend fusion to L4 when correcting pediatric L5-S1 spondylolisthesis?

The objective of this study was to investigate whether extending fusion to L4 is imperative in the surgical treatment of pediatric L5-S1 spondylolisthesis. This retrospective analysis encompassed 68 pediatric cases of dysplastic L5-S1 spondylolisthesis who underwent posterior lumbar interbody fusion surgery at two hospitals. Patients were categorized into two groups based on the upper instrumented vertebra (group L4 and group L5). Data were collected from medical records and radiological images obtained preoperatively and at last follow-up. Radiographic parameters including slip percentage (SP), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), Spinal Deformity Study Group dysplastic lumbosacral angle (SDSG-LSA), pelvic tilt (PT), Dubousset's lumbosacral angle (Dub-LSA), sacral slope (SS), and severity index (SI) were measured. Surgery-related data and complication data were also collected. The incidence rates of complications were compared, including those of neurological deficit, adjacent-segment instability (ASI), and other complications. ASI was defined as progression of slippage > 3 mm or posterior opening > 5° in the adjacent segment. Clinical outcomes were assessed with the numeric rating scale (NRS) and the Oswestry Disability Index (ODI) scores. The follow-up period for all patients lasted a minimum of 2 years. Among all 68 patients, group L4 consisted of 15 patients and group L5 comprised 53 patients. The patients included in both groups had comparable baseline demographic characteristics and radiographic parameters. Postoperative SP and SDSG-LSA were significantly lower in group L5 (p < 0.05). No other postoperative radiographic differences were observed between groups. One patient in group L4 and 3 patients in group L5 experienced transient neurological deficits (p > 0.05). There were 13 cases of ASI in group L5 compared with none in group L4 (24.5% vs 0%, p > 0.05). Of the 13 patients with ASI, 4 underwent revision surgery due to L4-5 level instability and clinical symptoms. The remaining individuals exhibited no symptoms, and regular annual follow-up assessments are being conducted for all patients. The NRS and ODI scores at final follow-up did not exhibit any significant differences between the two groups. Fusion to L5 could achieve comparable satisfactory results to fixation to L4, albeit with increased likelihood of ASI. Extension of fusion to L4 may not be necessary for most patients with pediatric L5-S1 spondylolisthesis.

A comparative study of perioperative pain, blood loss, and hospital stay in an Indian population undergoing mini-open oblique lumbar interbody fusion versus open transforaminal lumbar interbody fusion.

There are several approaches for lumbar fusion, although there is yet to be a consensus on which approach is the best. This study aimed to evaluate the intraoperative blood loss and acute postoperative pain in single-level mini-open oblique lumbar interbody fusion (OLIF) versus open transforaminal lumbar interbody fusion (TLIF) surgeries for the degenerative spine. Thirty-two patients were assigned by the surgeon to OLIF or TLIF groups - 16 in mini-open OLIF and 16 in open TLIF groups. The intraoperative blood loss and postoperative hemoglobin, numerical rating scale (NRS) at proposed time intervals for 24 h postoperative, and rescue analgesics used were compared among the groups. The operative duration and hospital stay in both groups were also compared. The OLIF group showed significantly higher postoperative hemoglobin (11.5 vs. 10.5 g %, P = 0.04), lower 24-h postoperative pain scores on movement, (NRS 4 vs. 5.5, P = 0.0001), and shorter hospital stay (4.5 vs. 7 days, P = 0.003) than TLIF group. However, the surgery duration was significantly longer in OLIF than in TLIF (190 vs. 150 min, P = 0.005). Intraoperative hemodynamics, other postoperative pain scores at variable time points, and rescue analgesics given were comparable among groups (P > 0.05). Intraoperative blood loss was lower in OLIF than TLIF (275 vs. 500 mL) but was not statistically significant (P > 0.05). Mini-open OLIF has favorable perioperative outcomes compared to open TLIF. Patients have higher postoperative hemoglobin and lesser pain on movement on the first postoperative day, leading to earlier mobilization and a shorter hospital stay.

Improved intervertebral fusion in LLIF rabbit model with a novel titanium cage

BACKGROUND CONTEXTThere is no established small animal approach model for the strict simulation of lateral lumbar interbody fusion (LLIF) surgery. PURPOSEThis study aims to establish a reliable LLIF rabbit model that strictly simulates the procedure and to preliminarily evaluate the differences in fusion outcomes with different graft materials. STUDY DESIGNA controlled laboratory. METHODSFifty-four 4-month-old white New Zealand female and male rabbits were selected and divided into five groups: Group A (dissection group) consisted of 9 rabbits, Group B (normal approach group) consisted of 9 rabbits, Group C (autogenous iliac bone group) consisted of 12 rabbits, Group D (BMP-2 carrier material group) consisted of 12 rabbits, and Group E (allograft bone group) consisted of 12 rabbits. Based on data from Group A, a novel titanium metal fusion device was designed. Postoperatively, at the 12-week mark, manual palpation was employed to compare the interbody fusion status among Groups B, C, D, and E. Specimens from Groups C, D, and E were subjected to Micro-CT scanning to compare various parameters such as trabecular bone volume (BV), bone volume fraction (BV/TV, BVF), and bone surface area (BS). Furthermore, a tissue histopathological examination was performed to observe the structure and morphology of newly formed bone within the fusion mass as well as the remodeling of the graft in each group. RESULTSBased on the measurements obtained from the dissection group, we designed a U-shaped interbody fusion device with dimensions of 10 mm in length, 2.5 mm in width, and 1.3 mm in height. In Group B, 9 cases exhibited intervertebral mobility. In Group C, 1 case showed nonfusion. In Group D, all cases achieved fusion. In Group E, 4 cases did not achieve fusion. Additionally, the Micro-CT results showed that the interbody fusion index scores were 4.64±0.50 in Group C, 4.33±0.65 in Group D, and 3.36±0.81 in Group E. There was no statistically significant difference in fusion index scores between Groups C and D (p=.853). Notably, Groups C and D had higher scores than Group E (p<.001). The trabecular bone volume (BV) in Groups C and D also showed no significant difference but was significantly higher than in Group E (p<.001). Furthermore, the histopathological results revealed that the specimens from Group E had less newly formed cartilage and bone compared to Groups C and D. CONCLUSIONSThis study successfully established a strict simulation of the clinical LLIF procedure in a rabbit model. Moreso, we conducted a preliminary validation indicating that the BMP-2 carrier material achieved interbody fusion outcomes similar to autogenous iliac bone. CLINICAL SIGNIFICANCEThe findings of this investigation from animal models provide a theoretical basis for the clinical use of BMP-2 to promote early spinal fusion in LLIF procedures. Importantly, the study provides a small animal model foundation for research related to LLIF surgery.

Intradural lumbar disc herniation at the L3–L4 level: A case report and literature review

Abstract Only 0.26% of all disc herniations are caused by intradural disc herniation (IDH), making it a rare pathology. We present the case of a 44-year-old man who suffered from right radicular low back pain and motor impairments. At the level of L3–L4, magnetic resonance imaging (MRI) revealed an intradural, extra-axial spinal mass. This individual had several specific MRI imaging characteristics. Laminectomy, durotomy, and transforaminal lumbar interbody fusion surgery was performed, and the disc was completely removed. At the 6-month follow-up, the patient showed full recovery. The diagnosis of IDH is very challenging and every spine surgeon must be aware. The best treatment for this pathology is surgical intervention.

Comparative Biomechanical Evaluation of Unilateral and Bilateral Cages in Posterior Lumbar Interbody Fusion: Endplates Subsidence, Pedicle Screw Loosening and Implant Stability

Implant sinking, pedicle screw loosening, and instability are commonly observed complications in posterior lumbar interbody fusion (PLIF) surgeries, attributed to a range of mechanical, biomechanical, and environmental factors. To address these challenges, the utilization of unilateral cages positioned obliquely, along with bilateral posterior instrumentation, and employing a material with a comparable modulus to cortical bone, has shown promising efficacy. The present study employed image-based finite element analysis (FEA) to evaluate the influences on cage sinking, screw loosening, and construct stability. The outcomes revealed that obliquely positioned unilateral fusion cage constructs with posterior instrumentation yielded superior biomechanical outcomes, characterized by reduced range of motion and stress distortion at the cage-endplate and screw-bone junctions. Furthermore, these findings indicated a lower risk of fractures and diminished deformations in normal and traumatic events. Hence, the utilization of biocompatible cage materials and structural symmetry holds critical significance for achieving biomechanical success in PLIF surgery.

Safety and benefit of ambulation within 24 hours in elderly patients undergoing lumbar fusion: propensity score matching study of 882 patients

BACKGROUND CONTEXTElderly patients are less likely to recover from lumbar spine fusion (LSF) as rapidly compared with younger patients. However, there is still a lack of research on the effect of early ambulation on elderly patients undergoing LSF surgery for lumbar degenerative disorders. PURPOSETo evaluate the safety and benefit of ambulation within 24 hours in elderly patients who underwent LSF. STUDY DESIGNA retrospective study. PATIENT SAMPLEConsecutive patients (aged 65 and older) who underwent elective transforaminal lumbar interbody fusion surgery for degenerative disorders from January 2019 to October 2022. OUTCOME MEASURESOutcome measures included postoperative complications, postoperative drainage (mL), laboratory test data, length of hospital stay (LOS), readmission and reoperation within 3 months. METHODSEarly ambulation patients (ambulation within 24 hours after surgery) were propensity-score matched 1:1 to a delayed ambulation patients (ambulation at a minimum of 48 hours postoperatively) based on age, intraoperative blood loss, and number of fused segments. The incidence of postoperative adverse events (AEs, including rates of complications, readmission, and prolonged LOS) and the average LOS were used to assess the safety and benefit of early ambulation, respectively. Multivariable regression analysis was performed to assess the association between early ambulation and postoperative AEs. The risk factors for delayed ambulation were also determined using multivariable logistic analyses. RESULTSA total of 998 patients with LSF surgery were reviewed in this study. After excluding 116 patients for various reasons, 882 patients (<24 hours: N=350, 24–48 hours: N=230, and >48 hours: N= 302) were included in the final analysis. After matching, sex, BMI, preoperative comorbidities, laboratory test data and surgery-related variables were comparable between the groups. The incidence of postoperative AEs was significantly lower in the EA group (44.3% vs 64.0%, p<.001). The average postoperative LOS of the EA group was 2 days shorter than the DA group (6.5 days vs 8.5 days, p<.001). Patients in the EA group had a significantly lower rate of prolonged LOS compared with the DA group (35.1% vs 55.3%, p<.001). There was no significant difference in postoperative drainage volumes between the two groups. Multivariable analysis identified older age (odds ratio [OR] 1.07, p<.001), increased intraoperative EBL (OR 1.002, p=.001), and higher international normalization ratio (OR 10.57, p=.032) as significant independent risk factors for delayed ambulation. CONCLUSIONSAmbulation within 24 hours after LSF surgery is independently associated fewer AEs and shorter hospital stays in elderly patients. Implementing the goal of ambulation within 24 hours after LSF surgery into enhanced recovery after surgery protocols for elderly patients seems appropriate. Older age, increased intraoperative blood loss and worse coagulation function are associated with delayed ambulation.

Vascular injury risk stratification for lateral lumbar interbody fusion (LLIF) at L4-L5: a morphometric study using magnetic resonance imaging.

Proper vascular injury risk stratification (VIRS) methods for L4-L5 lateral lumbar interbody fusion (LLIF) surgery have not been well-described. The objective of this study was to propose a novel VIRS method for L4-L5 LLIF surgery via the transpsoas approach. Axial magnetic resonance imaging (MRI) of adult patients were obtained and analyzed. The VIRS scores were assessed using anterior disc line to posterior vessel wall distance, the disc vessel angle (DVA), and the disc edge to vessel distance at the level of L4-L5 disc space. Ninety-one consecutive adult patients were included in the study. The right common iliac vein (CIV) had a high risk of injury with both right- and left-sided approaches. The left CIV had a moderate risk with a left-sided approach when the iliocaval confluence was above the L4-L5 disc space but had a high risk when the confluence was at the L4-L5 disc space. The left CIV had a high risk with a right-sided approach when the confluence was above the L4-L5 disc space but had a moderate risk when the confluence was at the L4-L5 disc space. The inferior vena cava (IVC) had a high risk with both right- and left-sided approaches. The aorta had a moderate risk regardless of the right or left-sided approaches. The left common iliac artery (CIA) had a moderate risk with a right-sided approach and a low risk with a left-sided approach. The right CIA had a low risk with both right- and left-sided approaches. There are significant vascular anatomic variations at the L4-L5 disc level and a proper VIRS can be performed utilizing a combination of anterior disc line to posterior vessel wall distance, DVA, and disc edge to vessel distance, on the axial MRI.

Effects of “fixation-fusion” sequence of lumbar surgery on surgical outcomes for patients with lumbar spinal stenosis: study protocol for a multicenter randomized controlled trial

BackgroundNew-onset neurological symptoms such as numbness and pain in lower extremities might appear immediately after conventional lumbar interbody fusion (LIF) surgery performed in patients with lumbar spinal stenosis.Methods and analysisThis is a multicenter, randomized, open-label, parallel-group, active-controlled trial investigating the clinical outcomes of modified LIF sequence versus conventional LIF sequence in treating patients with lumbar spinal stenosis. A total of 254 eligible patients will be enrolled and randomized in a 1:1 ratio to either modified LIF sequence or conventional LIF sequence group. The primary outcome measure is the perioperative incidence of new-onset lower extremity neurological symptoms, including new adverse events of pain, numbness, and foot drop of any severity. Important secondary endpoints include visual analogue scale (VAS) pain score and lumbar Japanese Orthopaedic Association (JOA) recovery rate. Other safety endpoints will also be evaluated. The safety set used for safety data analysis by the actual surgical treatment received and the full analysis set for baseline and efficacy data analyses according to the intent-to-treat principle will be established as the two analysis populations in the study.ConclusionThis study is designed to investigate the clinical outcomes of modified LIF sequences in patients with lumbar spinal stenosis. It aims to provide clinical evidence that the modified “fixation-fusion” sequence of LIF surgery is effective in treating lumbar spinal stenosis.Trial registrationhttp://www.chictr.org.cn/index.aspx ID: ChiCTR2100048507.

Compare the outcomes of minimally invasive versus opentransforaminal lumbar interbody fusion in treatment lumbar spinal stenosis

Background: Minimally invasive-transforaminal lumbar interbody fusion has become an effective method to treat lumbar spinal stenosis and is widely used. This article compares the effectiveness of minimally invasive and open transforaminal lumbar interbody fusion surgery in treating lumbar spinal stenosis. Methods: From 9/2018 to 10/2022, 104 patients with lumbar spinal stenosis were treated with transforaminal lumbar interbody fusion, including 52 cases in the minimally invasive surgery group and 52 cases in the open surgery group. Parameters such as surgery time, blood loss, postoperative time, hospital stay, and complications were recorded. The Visual Analog Scale (VAS) was used to assess low back and leg pain, and the Oswestry Disability Index (ODI) was used to assess pain and functional outcome in preoperation, three months, and six months after surgery. Follow-up plain X ray were taken to evaluate the fusion after 2 years. Results: The two groups found no significant differences in age, sex ratio, and percentage of cause spinal stenosis data. Compared with the open surgery group, the minimally invasive surgery group had less intraoperative blood loss (127.50 ± 27.99 mL vs 25.12 ± 62.05 mL, P &lt; 0.001), bed immobilization time shorter (1.21 ± 0.41 days versus 2.40 ± 0.60 days, P &lt; 0.001) and shorter postoperative hospital stay (4.42 ± 0.94 days versus 6.77 ± 1.13 days, P &lt; 0.001). VAS scores of low back pain and leg pain and ODI scores of the two groups decreased statistically significantly compared to before surgery, but there was no difference between the two groups after six months. X-ray showed no significant difference in fusion of the two groups. Conclusion: Our study showed that minimally invasive transforaminal lumbar interbody fusion is a safe and effective option in treating lumbar spinal stenosis and has the advantage of less blood loss and less hospital stay compared to open surgery. Key words: Transforaminal lumbar interbody fusion (TLIF), minimally invasive spine surgery, open spine surgery, spinal stenosis.

Postoperative Sclerotic Modic Changes After Transforaminal Lumbar Interbody Fusion: The Prevalence, Risk Factors, and Impact on Fusion.

A retrospective cohort study. This study aimed to assess postoperative sclerotic modic changes (MCs) following transforaminal lumbar interbody fusion for lumbar degenerative disc disease, investigating their prevalence, risk factors, and association with clinical outcomes. Sclerotic MCs may occur in patients with lumbar degenerative disc disease after lumbar interbody fusion. The incidence and characteristics of postoperative sclerotic MCs, as well as their clinical impact, are unknown. The study included 467 patients (510 levels) who underwent single or two-level transforaminal lumbar interbody fusion surgery, divided into a postoperative sclerotic MC group (60 patients, 66 levels) and a non-MC group (407 patients, 444 levels). The time of development and location of postoperative sclerotic MCs, fusion rate, cage subsidence, bilateral process decompression, and cross-link usage were recorded. Preoperative, postoperative, and follow-up visual analogue scale and Oswestry disability index scores were collected. Multivariable logistic regression was used to evaluate factors associated with the development of postoperative sclerotic MCs. The prevalence of postoperative sclerotic MCs was 12.8%. The postoperative sclerotic MC group had a higher body mass index (BMI). The postoperative sclerotic MC group demonstrated a fusion rate of 47%, significantly lower than that of the non-MC group (71%) at six months post-operation. At final follow-up, the fusion rate in the postoperative sclerotic MC group was 62%, significantly lower than that of the non-MC group (86%). Postoperative visual analogue scale and Oswestry disability index scores were significantly higher in the group with postoperative sclerotic MCs. BMI and osteoporosis were significantly associated with the development of postoperative sclerotic MCs. Postoperative sclerotic MCs generally appear within the first year after surgery, with a prevalence of 12.8%. The presence of postoperative sclerotic MCs can adversely impact postoperative outcomes. To prevent postoperative sclerotic MCs, the authors postulate extending the immobilization period with external bracing and improving the management of BMI and osteoporosis in the perioperative time window.

Comparison of Intraoperative Endplate Injury between Mini-Open Lateral Lumbar Interbody Fusion (LLIF) and Transforaminal Lumbar Interbody Fusion (TLIF) and Analysis of Risk Factors: A Retrospective Study

Objective The study aimed to compare the incidence of intraoperative endplate injury in patients who underwent Transforaminal interbody fusion (TLIF) and mini-open lumbar interbody fusion (LLIF) surgery. The independent risk factors related to endplate injury in LLIF procedure were analyzed. Methods A total of 199 patients who underwent LLIF (n = 106) or TLIF (n = 93) surgery from June 2019 to September 2021 were reviewed. The endplate injury was assessed by postoperative sagittal CT scan. A binary logistic analysis model were used to identify independent risk factors related to LLIF endplate injury based on univariate analysis. Results There was an obvious difference in the occurrence of intraoperative endplate injury between LLIF (42/106, 39.6%) and TLIF group (26/93, 28%), although it did not reach the significant level. L1 CT value (OR = 0.985, 95% CI = 0.972–0.998), cage position (OR = 3.881, 95% CI = 1.398–10.771) and height variance (OR = 1.263, 95% CI = 1.013–1.575) were independent risk factors for endplate injury in LLIF procedure. According to the cage settlement patterns, there 5 types of A to E. The severity of the facet joint degeneration was positively related to the occurrence of endplate injury. Conclusions The incidence of intraoperative endplate injury is higher in LLIF than in TLIF procedures. Low bone quantity, cage posterior position and larger height variance are risk factors to induce endplate injury in LLIF surgery. The facet joint degeneration may be related to severe endplate injuries and even fractures.