Posterior Lumbar Interbody Fusion Research Articles

Comparison of clinical and radiologic outcomes between biportal endoscopic transforaminal lumbar interbody fusion and posterior lumbar interbody fusion

Biportal endoscopic spinal surgery has become increasingly popular, and indications have expanded. Among these, biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) has yielded good results. Herein, we compared the clinical and radiological outcomes of 155 patients treated with BE-TLIF and open posterior lumbar interbody fusion (PLIF) for single-level lumbar degenerative diseases. Clinical outcomes included the visual analog scale for the back (VAS-back) and leg (VAS-leg), Oswestry Disability Index, and EuroQol 5-Dimensions. Radiological parameters and fusion rates were evaluated, and postoperative complications were recorded. In this cohort 68 and 87 patients were treated with BE-TLIF and PLIF, respectively. Both groups showed significant improvements in all clinical parameters compared with baseline, but BE-TLIF exhibited a more significant improvement in VAS-back at 1 and 6 months postoperatively. There were no significant differences in the radiological parameters or fusion rates. BE-TLIF had a significantly longer operation time, whereas PLIF exhibited a significantly higher estimated blood loss and surgical drainage, but no significant differences in postoperative complications. Compared to PLIF, BE-TLIF showed similarly good clinical and radiologic outcomes, with better results in terms of early postoperative outcomes. Thus, BE-TLIF is a viable alternative to PLIF with less back pain at 1 and 6 months postoperatively.

The Bony Density of the Pedicle Plays a More Significant Role in the Screw Anchorage Ability Than Other Regions of the Screw Trajectory.

Osteoporosis is a crucial risk factor for screw loosening. Our studies indicate that the bone mineral density (BMD) in the screw trajectory is a better predictor of screw loosening than the BMD of the lumbar spine or the screw insertion position. Research has shown that anchorage on the screw tip is the most significant factor for screw anchorage ability, while others argue that decreased bony quality in the pedicle poses a significant risk for screw loosening. This study aimed to determine whether the bony quality of the screw tip, pedicle, or screw-anchored vertebral body plays the most significant role in screw anchorage ability. A total of 73 patients who underwent single-segment bilateral pedicle screw fixation, along with posterior and transforaminal lumbar interbody fusion (PLIF and TLIF), from March 2019 to September 2020 were included in this retrospective study. The Hounsfield unit (HU) value of the fixed vertebral bodies, the entire screw trajectory, screw tip, screw-anchoraged vertebral body, and pedicles were measured separately. Data from patients with and without screw loosening were compared, and regression analyses were conducted to identify independent risk factors. Additionally, the area under the curve (AUC) values were computed to assess the predictive performance of different parameters. Furthermore, fixation strength was calculated in numerical models with varying bony densities in different regions. HU values were found to be significantly lower in the loosening group across most measuring methods (HU values in the pedicle, 148.79 ± 97.04, 33.06 ± 34.82, p < 0.001). Specifically, the AUC of screw loosening prediction was notably higher when using HU values of the pedicle compared to other methods (AUC in the pedicle > 0.9 and in the screw insertion position > 0.7). Additionally, computational results for fixation strength revealed a clear decline in screw anchorage ability in models with poor BMD in the pedicle region. Pedicle bone quality plays a more significant role in screw anchorage ability than that in other regions. The innovation of bony augmentation strategies should pay more attention to this region to optimize the screw anchorage ability effectively.

Clinical outcomes of revision posterior lumbar interbody fusion for late deterioration after laminotomy assessed with the Zurich Claudication Questionnaire.

A retrospective analysis of prospectively collected data. There have been a few studies comparing surgical outcomes between revision lumbar fusion surgery and the same primary surgery. Using the Zurich Claudication Questionnaire (ZCQ), we compared clinical outcomes of revision posterior lumbar interbody fusion (PLIF) for late deterioration after laminotomy with those of primary PLIF to examine whether surgical outcomes of revision PLIF for late deterioration after laminotomy are inferior to those of primary PLIF. Sixteen consecutive patients undergoing revision single-level PLIF for late deterioration after single-level laminotomy (R group) and 61 consecutive patients undergoing primary single-level PLIF during the same period as the R group (P group) were enrolled. Before PLIF surgery and at 2-year postoperatively, clinical outcomes were assessed using the ZCQ. Achievement rates of the minimum clinically important difference (MCID) of each domain [Symptom severity (SS) and Physical function (PF)] on the ZCQ were calculated in each group. In the R group, mean SS and PF before revision PLIF and at 2-year after surgery were 3.429 and 2.8, and 1.946 and 1.6, respectively. In the P group, mean SS and PF before primary PLIF and at postoperative 2-year were 3.438 and 2.5, and 2.194 and 1.6, respectively. Both SS and PF significantly improved at postoperative 2-year in the both groups, and SS both before and after PLIF and PF at 2-year postoperatively showed no significant differences between the 2 groups. Achievement rates of the MCID of SS and PF were 81.3% and 68.8% in the R group, and 59.0% and 59.0% in the P group, respectively. None of the MCID achievement rates of SS and PF showed significant differences between the 2 groups. Clinical outcomes of revision PLIF for late deterioration after laminotomy were equivalent to those of primary PLIF assessed with the ZCQ at 2 years after PLIF surgery.

Clinical Comparison of Endoscopic Posterior Lumbar Interbody Fusion and Open Posterior Lumbar Interbody Fusion for Treating Lumbar Spondylolisthesis.

A retrospective case-control study. To compare the clinical efficacy of endoscopic (Endo) and open posterior lumbar interbody fusion (PLIF) in treating lumbar spondylolisthesis. Endo-PLIF has emerged as a new technique for treating lumbar spondylolisthesis. We propose Endo-PLIF as an alternative method. Sixty-four patients with single-segment lumbar spondylolisthesis underwent Endo-PLIF (n = 39) or open PLIF (n = 25) treatment. Demographic data, perioperative parameters, and radiographic parameters were recorded. Clinical results were evaluated by Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores. The fusion rate was evaluated by computed tomography at 12 months postoperatively. In addition, a case-control process was included to ensure unbiased comparisons. The average operation time was longer in the Endo-PLIF group. Endo-PLIF showed advantages in reducing blood loss, shortening hospital stay, and early ambulation, but with a longer x-ray exposure time. Both VAS and ODI scores significantly improved in both groups, but the VAS for back pain was lower in the Endo-PLIF group. The radiographic results were similar in both groups. Three patients in the Endo-PLIF group had minor complications. Two patients in the open PLIF group experienced cerebrospinal fluid leakage. Both VAS and ODI scores significantly improved in both groups compared with preoperative scores, but the Endo-PLIF group showed more significant improvement at early follow-up (P < 0.05). There was no significant difference in interbody fusion rate between the two groups. Both Endo-PLIF and open PLIF are effective for treating single-segment lumbar spondylolisthesis. Endo-PLIF shows advantages in reducing blood loss, shortening hospital stays, and promoting early ambulation, with comparable fusion rates and patient satisfaction to open PLIF. Despite minor complications in the Endo-PLIF group and cerebrospinal fluid leakage in the open PLIF group, both procedures lead to significant improvements in pain and disability scores, with Endo-PLIF demonstrating more significant early improvements.

Mid-term efficacy of non-contact orthopedic robot navigation in the treatment of lumbar spondylolisthesis

ObjectiveThis study was aimed to explore the mid-term efficacy of non-contact orthopedic robot navigation in the treatment of lumbar spondylolisthesis.MethodsThe clinical data of young and middle-aged patients with lumbar spondylolisthesis were retrospectively analyzed and divided into an observation group and a control group according to surgical methods. The observation group was treated with minimally invasive transforaminal interbody fusion (MIS-TLIF) combined with orthopedic robot-navigated percutaneous pedicle screw fixation; while the control group underwent traditional posterior lumbar interbody fusion (PLIF). Perioperative indicators, waist and leg pain Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI), and complications were compared between groups.ResultsA total of 32 patients with lumbar spondylolisthesis were included in this study, with the average age of 50.3 ± 2.7 years old. There were 17 patients in the observation group and 15 patients in the control group. Although the new surgical technique for the observation group may require longer operative time, it showed significant advantages in reducing intraoperative bleeding, postoperative drainage, and shortening hospital stay. These benefits might result in faster recovery for patients, reduced risk of complications, and improved overall quality of life. The new technology was also significantly better compared to the traditional method in terms of VAS scores and ODI at 1 week, 1 month, 3 months, and 6 months post-surgery. These results provided patients with better treatment options and potentially a faster path to recovery. One case with infectious incision in the observation group and one case with intraspinal hematoma formation in the control group were observed. However, there was no statistical difference in the complication rates between the two groups (P > 0.05).ConclusionThe non-contact orthopedic robot navigation for the treatment of lumbar spondylolisthesis was demonstrated to be minimally invasive, precise, and stable surgical method. It is a treatment option worth considering for suitable patients.

Development and Validation of Deep Learning Preoperative Planning Software for Automatic Lumbosacral Screw Selection Using Computed Tomography.

Achieving precise pedicle screw placement in posterior lumbar interbody fusion (PLIF) is essential but difficult due to the intricacies of manual preoperative planning with CT scans. We analyzed CT data from 316 PLIF patients, using Mimics software for manual planning by two surgeons. A deep learning model was trained on 228 patients and validated on 88 patients, assessing planning efficiency and accuracy. Automatic planning successfully segmented and placed screws in all 316 cases, significantly outperforming manual planning in speed. The Dice coefficient for segmentation accuracy was 0.95. The difference in mean pedicle transverse angle (PTA) and pedicle sagittal angle (PSA) for automatic planning screws compared to manual planning screws was 1.63 ± 0.83° and 1.39 ± 1.03°, respectively, and these differences were either statistically comparable or not significantly different compared to the variability of manual planning screws. The average Dice coefficient of implanted screws was 0.63 ± 0.08, and the consistency between automatic screws and manual reference screws was higher than that of internal screws (Dice 0.62 ± 0.09). Compared with manual screws, automatic screws were shorter (46.58 ± 3.09 mm) and thinner (6.24 ± 0.35 mm), and the difference was statistically significant. In qualitative validation, 97.7% of the automatic planning screws were rated Gertzbein-Robbins (GR) Class A and 97.3% of the automatic planning screws were rated Badu Class 0. Deep learning software automates lumbosacral pedicle screw planning, enhancing surgical efficiency and accuracy.

A case of consecutive four-level lumbar spondylolysis and spondylolisthesis

This rare and unusual case is about a 54-year-old female, who has pars fractures involving consecutive four-level bilateral spondylolysis and spondylolisthesis. Due to the increasing intensity with lumbar instability, the patient had severe low back pain. For diagnosis, dynamic X-ray, magnetic resonance, 3D tomography were performed, and bilateral L2-3-4-5 pars fracture and L3-4 spondylolisthesis were observed. This case was treated surgically byspinal canal decompression at L3-4, L4-5 and L5-S1, posterior lumbar interbody fusion at L4–5 and L5–S1, and pedicle screw fixation at L2–S1. The lower back pain disappeared after the surgery.

Structural design and biomechanical analysis of a combined titanium and polyetheretherketone cage based on PE-PLIF fusion.

In lumbar spinal fusion, the titanium cage tends to cause stress shielding due to their high elastic modulus, which can lead to degenerative lesions in adjacent spinal segments. Furthermore, polyetheretherketone (PEEK) cages have certain material characteristics that do not promote bone ingrowth and fusion stability. In this study, a new cage was designed, and its biomechanical performance in percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) was analyzed using the finite element (FE) method. A complete model of the L4-L5 lumbar spine was established, and static and harmonic vibration FE analysis models were developed based on it. The biomechanical properties of titanium, PEEK, and combined cage in PE-PLIF fusion were compared. The strain capacity of the combined fusion increased by 9.5% when compared to the titanium fusion. The surgical model under the combined fusion reduces the L5 endplate stress by 12% in the forward flexion condition and the fusion stress by 17% in the vibration condition compared to the model supported by the titanium fusion, and the differences in screw stress and mobility among the three models are not significant in multiple conditions. Consequently, the combined cage demonstrates a certain reduction in the stress-shielding effect when compared to the titanium cage; it has better fusion effect and provides theoretical support and guidance for the design of the clinical fusion cage.

Observation of the effect of single dose intravenous infusion of tranexamic acid on white blood cell, erythrocyte sedimentation rate and C-reactive protein after double segmental posterior lumbar interbody fusion

To observe the safety and effectiveness of single dose intravenous infusion of tranexamic acid (TXA) in dual level posterior lumbar interbody fusion (PLIF), and to explore the changes and trends in perioperative white blood cell (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Between October 2020 and September 2022, 46 patients with lumbar degenerative disease were treated with dual level PLIF, including 18 males and 28 females, with an average age of (60.24±10.68) years old, from 34 to 80 years old. They were divided into observation group and control group according to different treatment methods. There were 28 patients in the observation group, including 12 males and 16 females, with an average age of (61.04 ± 9.03) years old. There were 3 cases with lumbar disc herniation (LDH), lumbar spinal stenosis (LSS) 18 cases, lumbar spondylolisthesis (LS) 7 cases. TXA (1 g/100 ml) was administered intravenously 15 min before skin incision after general anesthesia. The control group consisted of 18 patients, including 6 males and 12 females, with an average age of (59.00±13.04) years old. There were 5 cases with LDH, LSS 9 cases, LS 4 cases, and TXA was not used. The operation time, intraoperative bleeding volume, postoperative drainage volume, postoperative deep vein thrombosis (DVT), postoperative hospital stay, postoperative activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen (FIB), platelet (PLT), red blood cell (RBC), hemoglobin (HB), hematocrit (HCT), the first day, the fourth day, the seventh day and the last tested after operation WBC, ESR and CRP were recorded. The postoperative wounds of the patients healed well and there was no DVT. 46 patients were followed up from 3 to 6 months. The intraoperative blood loss was 400.0 (300.0, 500.0) ml and the postoperative drainage was 260.0 (220.0, 450.0) ml in the observation group, which were lower than the control group[600.0(400.0, 1000.0) ml, 395.0 (300.0, 450.0) ml], P<0.05. There was no significant difference between the two groups in operation time, postoperative hospital stay, postoperative APTT, PT, TT, FIB, PLT, RBC, HB, HCT, and postoperative WBC, ESR and CRP at different times (P>0.05). Single dose intravenous infusion of TXA can reduce the blood loss of bi-segmental PLIF, and has no significant effect on WBC, ESR and CRP after operation.

Novel Technique for Degenerative Lumbar Spine Fusion: Unilateral Pedicle Screw Fixation Combined with Contralateral Interbody Cage Fusion for Posterior Lumbar Interbody Fusion

Abstract Objective The common traditional surgical techniques for posterior lumbar interbody fusion (PLIF) and fixation are bilateral pedicle screw fixation with or without interbody cage fusion and unilateral pedicle screw fixation with ipsilateral cage fusion. However, the novel unilateral pedicle screw fixation combined with the contralateral interbody cage fusion technique may provide the benefits and avoid the hazards of those traditional techniques. This prospective randomized comparative clinical trial aims to compare pedicle screw fixation with contralateral interbody cage fusion and unilateral pedicle screw fixation with ipsilateral cage fusion in single-level PLIF and fixation. Methods This comparative prospective study was conducted on 60 patients subjected to a single-level PLIF and unilateral pedicle screw fixation during the period from January 2022 to July 2022 to compare two different surgical modalities: group A (unilateral pedicle screw fixation with contralateral interbody cage fusion) and group B (unilateral pedicle screw fixation with ipsilateral cage fusion). Results Operative time, blood loss, operative complications, and visual analog scale improvements showed insignificant differences between the two groups, while group A showed significant improvements in the Oswestry Disability Index and wider coronal disc heights contralateral to the screw, which is the side of the cages, during postoperative follow-up. Conclusion Unilateral pedicle screw fixation with contralateral cage fusion during the PLIF and pedicle screw fixation procedure is preferred to maintain bilateral coronal disc heights and thus better clinical and mechanical results without affection of the preceding disc.

The geriatric nutritional risk index predicts blood transfusion risk in elderly patients undergoing posterior lumbar interbody fusion: a retrospective study

BackgroundMalnutrition can lead to an increased risk of blood transfusion in elderly patients. The Geriatric Nutritional Risk Index (GNRI) is a tool used to assess nutritional status, but its predictive value for blood transfusion in elderly patients undergoing posterior lumbar interbody fusion (PLIF) is not well established. This study aimed to investigate the association between GNRI and the risk of perioperative blood transfusion in this population.MethodsA retrospective cohort study was conducted on elderly patients aged 60 and above who underwent PLIF at Qingdao University Affiliated Hospital. Preoperative GNRI was calculated using height, weight, and serum albumin levels. The primary outcome was perioperative blood transfusion. Logistic regression analysis was performed, adjusting for potential confounders such as demographic characteristics, comorbidities, surgical factors, and laboratory tests.ResultsA total of 1,246 elderly patients were included, with 144 (11.6%) requiring blood transfusion. After adjusting for all confounders, a lower GNRI was associated with a significantly higher risk of blood transfusion (OR = 2.4, 95% CI: 1.9–3.1, p < 0.001). Patients with a GNRI score below 92 had a significantly increased transfusion risk compared to those with normal GNRI scores (OR = 5.8, 95% CI: 3.7–9.1, p < 0.05). RCS analysis revealed a linear negative relationship between GNRI and transfusion risk.ConclusionThe GNRI is a strong predictor of perioperative blood transfusion risk in elderly patients undergoing PLIF. Preoperative nutritional assessment using GNRI may help identify high-risk patients, enabling tailored interventions to optimize outcomes.

Comparison of Hounsfield Unit, Vertebral Bone Quality, and Dual-Energy X-Ray Absorptiometry T-Score for Predicting Cage Subsidence After Posterior Lumbar Interbody Fusion.

Retrospective cohort study. To compare Hounsfield unit (HU), vertebral bone quality (VBQ), and dual-energy X-ray absorptiometry (DEXA) T-score in predicting cage subsidence (CS) after posterior lumbar interbody fusion. We retrospectively reviewed patients undergoing PLIF and measured L4 HU and VBQ. Baseline characteristics between CS and non-CS groups were compared. Multiple logistic regression analysis was used to identify risk factors for CS. Receiver operating characteristic (ROC) curves were used to explore the predictive value of variables for CS. Subgroup analysis was conducted for patients with available DEXA results. Eighty-four patients were analyzed. The subsidence group was older, with lower L4 HU (92.6 (35.4) vs 130.8 (47.8), P < 0.001) and higher VBQ (3.30 (0.64) vs 2.99 (0.63), P = 0.041) compared to the non-CS group. Low L4 HU (OR 0.979, P = 0.022) was an independent risk factor for subsidence, while VBQ was not. ROC analysis indicated that L4 HU (AUC = 0.733, P < 0.001) exhibited superior predictive performance compared to VBQ (AUC = 0.643, P = 0.032). Subgroup analysis in patients with DEXA showed that the femoral neck T-score (AUC = 0.67, P = 0.037) could differentiate CS, with L4 HU exhibiting the highest predictive ability (AUC = 0.778, P < 0.001), both outperforming VBQ (AUC = 0.645, P = 0.075). Among the three BMD parameters, only low L4 HU could be an independent risk factor for CS. Preoperative HU is mandatory in patients at risk for osteoporosis when undergoing spine surgery.

Trans-Pars Interarticularis Approach for Lumbar Interbody Fusion: An Efficient, Straightforward, and Minimally Invasive Surgery for Lumbar Spondylolisthesis and Stenosis.

Lumbar interbody fusion is a commonly applied surgical treatment for spondylolisthesis. For this procedure, various minimally invasive (MIS) approaches have been developed, including posterior lumbar interbody fusion, transforaminal lumbar interbody fusion (TLIF), oblique lumbar interbody fusion, and anterior lumbar interbody fusion. In this study, we characterized the features of an MIS trans-pars interarticularis lumbar interbody fusion (TPLIF) and compared its surgical outcomes with those of MIS-TLIF. This study included 89 and 44 patients who had undergone MIS-TPLIF and MIS-TLIF, respectively, between September 2016 and December 2022. The following clinical outcomes were analyzed: operative time, blood loss, and hospitalization duration. The average operative time, blood loss, and hospitalization duration for the MIS-TPLIF and MIS-TLIF groups were, respectively, 98.28 and 191.15 minutes, 41.97 and 101.85 mL, and 5.8 and 6.9 days. The MIS-TPLIF approach for lumbar spondylolisthesis or other degenerative diseases involves the use of the commonly available and cost-effective instrument Taylor retractor, thus enabling posterior lumbar interbody fusion to be performed with minimal invasion. This approach also confers the benefits of a short learning curve and an intuitive approach. Our results suggest that although MIS-TPLIF is noninferior to MIS-TLIF, it is easier to learn and perform than MIS-TLIF.

Is ABO blood type a risk factor for adjacent segment degeneration after lumbar spine fusion?

This study aimed to explore associations between ABO blood type and postoperative adjacent segment degeneration/disease (ASD) following lumbar spine fusion, as well as evaluate differences in spinopelvic alignment, perioperative care, postoperative complications, and patient-reported outcome measures (PROMs). An ambispective study was performed. Patients who underwent posterolateral or posterior lumbar interbody fusion were included. Demographic, perioperative and postoperative, clinical, and blood type information was recorded. Pre- and post-operative radiographic imaging was analyzed for alignment parameters and development of ASD. 445 patients were included, representing O+ (36.0%), O- (5.2%), A+ (36.2%), A- (6.3%), B+ (12.1%), B- (1.6%), and AB+ (2.7%) blood types. Most patients were female (59.1%), and had a mean age of 60.3 years and BMI of 31.1kg/m2. Postoperatively, groups did not differ in duration of the hospital (p = 0.732) or intensive care unit (p = 0.830) stay, discharge disposition (p = 0.504), reoperation rate (p = 0.192), or in-hospital complication rate (p = 0.377). Postoperative epidural hematoma was most common amongst A + patients (p = 0.024). Over a mean of 11.0 months of follow-up, all patients exhibited similar improvement in PROMs, with 132 (29.7%) patients developing radiographic evidence of ASD. B + patients were significantly more likely than A + and O + patients to develop spondylolisthesis and ASD (p < 0.05). No significant differences in sagittal alignment parameters and number of levels of fusion were found (p > 0.05). This is the first large-scale study to address and demonstrate proof-of-principle that ABO blood type, a non-modifiable risk factor, is associated with ASD following lumbar spine fusion.

Comparison of patient outcomes of anterior and posterior lumbar interbody fusions: A retrospective national database analysis

BackgroundLumbar interbody fusions are used to treat degenerative lumbar disease unresponsive to conservative treatment. This procedure may be divided into anterior lumbar interbody fusion (ALIF), and posterior lumbar interbody fusion (PLIF/TLIF). Despite their widespread use, comparative research on their outcomes remains limited. MethodsThe PearlDiver Database was utilized to identify patients undergoing single and multi-level ALIF and PLIF/TLIF between 2010 and 2022. We examined demographic data, comorbidities, and reoperation rates at 90 days, 1 year, and 2 years. Complications were assessed using multivariable regression to adjust for confounders. ResultsThe study included multi-level anterior interbody fusions (N = 569, mean age 59.8, 59 % female), multi-level posterior interbody fusions (N = 43,651, mean age 57.9, 60 % female), single-level anterior interbody fusions (N = 3,547, mean age 55.3, 61 % female) and single-level posterior interbody fusions (N = 25,792, mean age 56.9, 62 % female). Multi-level posterior interbody fusion patients had a lower prevalence of HTN (OR .77, P < .05), ischemic heart disease (OR .73, P < .05), CDK (OR .77, P < .05), postoperatively more DVTs (OR 1.44, P < .05), a lower incidence of respiratory failure (OR .57, P < .05), and a higher 90-day, 1-year, and 2-year all-cause reoperation rate (7.3 %) compared to multi-level anterior interbody fusion patients (3.7 %). Single-level posterior interbody fusion patients had more HTN (OR 1.1, P < .05), less ischemic heart disease (OR .89, P < .05), obesity (OR .92, P < .05), and postoperatively a higher incidence of DVT (OR 1.34, P < .05) but lower 90-day, 1-year, and 2-year all-cause reoperation rates. ConclusionsThis study confirms that posterior interbody fusions are more common than anterior procedures, though the latter is increasing. Reoperation rates are higher for multi-level posterior and single-level anterior fusions. Both anterior and posterior approaches show similar complication profiles, though specific risks, such as postoperative DVT, vary. These findings emphasize the need for ongoing research and consideration of individual patient factors when choosing an interbody fusion technique.

Comparison of capsule and posterior lumbar interbody fusion in cauda equina syndrome with retention: a 24-month follow-up study

Background and objectivesCauda equina syndrome with retention (CESR) is a severe lumbar condition characterized by painless urine retention due to cauda equina nerve injury. The standard treatment, posterior lumbar interbody fusion (PLIF), often yields suboptimal results. This study aims to compare the clinical safety and efficacy of a novel technique, capsule lumbar interbody fusion (CLIF), with PLIF in CESR patients, hypothesizing that CLIF can enhance neurological recovery by reducing nerve tension.MethodsA single-center, retrospective study was conducted on 83 patients with CESR due to lumbar disc herniation, who underwent either PLIF (n = 44) or CLIF (n = 39). Patients were assessed preoperatively and at 3, 12, and 24 months postoperatively using the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), International Consultation on Incontinence Questionnaire Short Form (ICI-Q-SF), and Rintala score. Urodynamic studies and nerve tension measurements were also performed. Statistical analysis included t tests, Mann–Whitney U tests, and Spearman’s correlation.ResultsBoth groups showed significant postoperative improvements, but the CLIF group had superior outcomes. At 12 months, the CLIF group had lower VAS scores (1.15 ± 0.84 vs. 1.68 ± 0.60, p = 0.001) and ODI scores (23.31 ± 7.51 vs. 28.30 ± 8.26, p = 0.005). At 24 months, the CLIF group continued to show better results with ODI scores (15.97 ± 6.43 vs. 22.11 ± 6.41, p < 0.001) and higher ODI recovery rates (60.41 ± 17.6% vs. 44.71 ± 18.99%, p < 0.001). The CLIF group also had better ICI-Q-SF scores (2.13 ± 1.23 vs. 3.02 ± 1.45, p = 0.004) and Rintala scores (17.97 ± 1.43 vs. 16.59 ± 1.54, p < 0.001). Lower postoperative nerve tension in the CLIF group correlated with these improved outcomes.ConclusionsCLIF demonstrated superior efficacy over PLIF in treating CESR, with significant improvements in pain relief, functional recovery, and bladder and bowel function. This study highlights the potential of CLIF as a more effective surgical option for CESR, emphasizing its importance in improving patient outcomes and reducing the burden of CESR on patients and society.

Biomechanical properties analysis of posterior lumbar interbody fusion with transpedicular oblique screw fixation

ObjectiveAn alternative to conventional posterior lumbar interbody fusion (PLIF) is a PLIF with transpedicular oblique screw fixation system. An assessment of new fixation system's viability and efficacy is conducted through a comparison of its biomechanical properties with those of conventional PLIF. MethodA comprehensive finite element model (FEM) of the lumbar regions L1-L5 was developed and the surgical segment L3-L4 was chosen to comprise the surgical models of both traditional PLIF and new PLIF. In new PLIF model, an analysis was conducted on segmental range of motion (RoM), cage stress, inferior endplates stress, vertebral stress, and internal fixation stress. Three-dimensional printers are utilized to fabricate and assemble the fusion cage and vertebrae, and compression test machines are employed to execute physiological load and extreme load experiments on new PLIF, so as to verify the accuracy of the FEM analysis and the mode of fatigue exhibited by new PLIF. ResultsIn new PLIF, the maximum stress on the inferior endplates under physiological loads was reduced in comparison to conventional PLIF. While the maximum stress on the cage, vertebral body, and screw increased, it remained within an acceptable range. The experimental data indicates that new fixation system can endure a vertical load exceeding 2800 N and an ultimate bending moment of 77 Nm. ConclusionThe new PLIF exhibits a comparable RoM to its predecessor, simultaneously mitigating inferior endplate stress and accommodating physiological loads, which reduce the amount of surgical incision and fusion fixation instruments. Consequently, it emerges as a sanguine surgical approach to fuse the degenerative lumbar spine.

Development of machine learning model for predicting prolonged operation time in lumbar stenosis undergoing posterior lumbar interbody fusion: a multicenter study

BACKGROUND CONTEXTLonger posterior lumbar interbody fusion (PLIF) surgeries for individuals with lumbar spinal stenosis are linked to more complications and negatively affect recovery after the operation. Therefore, there is a critical need for a method to accurately predict patients who are at risk for prolonged operation times. PURPOSEThis research aimed to develop a clinical model to predict prolonged operation time for patients undergoing PLIF procedures. STUDY DESIGN/SETTINGThis study employs a machine-learning approach to analyze data retrospectively collected. PATIENT SAMPLEAbout 3,233 patients diagnosed with lumbar spinal stenosis (LSS) had posterior lumbar interbody fusion (PLIF) at 22 hospitals in China from January 2015 to December 2022. OUTCOME MEASURESThe primary outcome was operation time. Prolonged operation time defined as exceeded 75% of the overall surgical duration, which mean exceeding 240 minutes. METHODSA total of 3,233 patients who underwent PLIF surgery with lumbar spinal stenosis (LSS) were divided into one training group and four test groups based on different district areas. The training group included 1,569 patients, while Test1 had 541, Test2 had 403, Test3 had 351, and Test4 had 369 patients. Variables consisted of demographics, perioperative details, preoperative laboratory examinations and other Additional factors. Six algorithms were employed for variable screening, and variables identified by more than two screening methods were incorporated into the final model. In the training cohort, a 10-fold cross-validation (CV) and Bayesian hyperparameter optimization techniques were utilized to construct a model using eleven machine learning algorithms. Following this, the model was evaluated using four separate external test sets, and the mean Area Under the Curve (AUC) was computed to determine the best-performing model. Further performance metrics of the best model were evaluated, and SHapley Additive exPlanations (SHAP) were used for interpretability analysis to enhance decision-making transparency. Ultimately, an online calculator was created. RESULTSAmong the various machine learning models, the Random Forest achieved the highest performance in the validation set, with AUROC scores of 0.832 in Test1, 0.834 in Test2, 0.816 inTest3, 0.822 in Test4) compared with other machine learning models. The top contributing variables were number of levels fusion, pre-APTT, weight and age. The predictive model was further refined by developing a web-based calculator for clinical application (https://wenle.shinyapps.io/PPOT_LSS/). CONCLUSIONSThis predictive model can facilitate identification of risk for prolonged operation time following PLIF surgery. Predictive calculators are expected to improve preoperative planning, identify patients with high risk factors, and help clinicians facilitating the improvement of treatment plans and the implementation of clinical intervention.

The Utility of Magnetic Resonance Imaging-based Vertebral Bone Quality Scores as a Predictor of Cage Subsidence Following Transforaminal and Posterior Lumbar Interbody Fusion.

Retrospective study. The objectives were to determine whether vertebral bone quality (VBQ) scores are associated with interbody cage subsidence following transforaminal (TLIF) and posterior (PLIF) lumbar interbody fusions and whether there is a clinically sensitive threshold for subsidence. Interbody cage subsidence following lumbar fusion is a complication that can generate poor surgical outcomes. Prior research has correlated cage subsidence with bone mineral density. VBQ scores derived from magnetic resonance imaging (MRI) have been proposed as a tool for measuring bone mineral density, offering a potential new and convenient preoperative risk assessment tool for subsidence. The study involved patients undergoing single-level PLIF or TLIF between 2007 and 2022. Exclusions were for nondegenerative diagnoses, multilevel/revision surgeries, inadequate radiographs, missing immediate postoperative radiographs, and preoperative MRI studies older than 1 year. VBQ was calculated at L1-L4 from preoperative T1-weighted MRI images. Subsidence was assessed by changes in disc height (DH; >2mm difference) and segmental lordosis (SL; >5 degrees difference) between immediate weight-bearing postoperative and latest postoperative lateral radiographs. Statistical analysis included descriptive and inferential statistics. Subsidence was observed in 27% (SL parameter) and 47% (DH parameter) of 51 total patients. VBQ scores were significantly associated with cage subsidence based on both SL (odds ratio = 7.750, P = 0.012; correlation coefficient = 0.382, P = 0.006) and DH (odds ratio = 4.074, P = 0.026; correlation coefficient = 0.258, P = 0.057) in the combined TLIF/PLIF cohorts. In the cohort of 36 patients undergoing TLIF, a VBQ of 2.70 yielded 100.0% sensitivity and 46.2% specificity in detecting subsidence with SL measurement (area under the curve = 0.812, P < 0.001) and 86.7% sensitivity and 47.6% specificity with the DH measurement (area under the curve = 0.692, P = 0.033). We found that MRI-based VBQ scores are effective predictors of cage subsidence following TLIF surgery. A VBQ score of 2.70 demonstrated a reliable model and high sensitivity for doing so, identifying a potential clinical threshold for preoperative subsidence risk assessment. Level III.

Feasibility of the Non-Window-Type 3D-Printed Porous Titanium Cage in Posterior Lumbar Interbody Fusion: A Randomized Controlled Multicenter Trial.

Three-dimensionally printed titanium (3D-Ti) cages can be divided into 2 types: window-type cages, which have a void for bone graft, and non-window-type cages without a void. Few studies have investigated the necessity of a void for bone graft in fusion surgery. Therefore, the present study assessed the clinical and radiographic outcomes of window and non-window-type 3D-Ti cages in single-level posterior lumbar interbody fusion. A total of 70 patients were randomly assigned to receive either a window or non-window cage; 61 patients (87%) completed final follow-up (32 from the window cage group, 29 from the non-window cage group). Radiographic outcomes, including fusion rates, subsidence, and intra-cage osseointegration patterns, were assessed. Intra-cage osseointegration was measured using the intra-cage bridging bone score for the window cage group and the surface osseointegration ratio score for the non-window cage group. Additionally, we looked for the presence of the trabecular bone remodeling (TBR) sign on computed tomography (CT) images. Of the 61 patients, 58 achieved interbody fusion, resulting in a 95.1% fusion rate. The fusion rate in the non-window cage group was comparable to, and not significantly different from, that in the window cage group (96.6% and 93.8%, p > 0.99). The subsidence rate showed no significant difference between the window and non-window cage groups (15.6% and 3.4%, respectively; p = 0.262). The intra-cage osseointegration scores showed a significant difference between the groups (p = 0.007), with the non-window cage group having a higher proportion of cases with a score of 4 compared with the window cage group. The TBR sign was observed in 87.9% of patients who achieved interbody fusion, with a higher rate in the non-window cage group across the entire cohort although the difference was not significant (89.7% versus 78.1%, p = 0.385). Non-window-type 3D-Ti cages showed equivalent clinical outcomes compared with window-type cages and comparable interbody fusion rates. These results suggest that the potential advantages of 3D-Ti cages could be optimized in the absence of a void for bone graft by providing a larger contact surface for osseointegration. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.