Posterior Lumbar Interbody Fusion Research Articles

Clinical efficacy of unilateral two-channel spinal endoscopy and traditional posterior lumbar interbody fusion in the treatment of degenerative diseases of the lumbar spine.

Clinical efficacy of unilateral two-channel spinal endoscopy and traditional posterior lumbar interbody fusion in the treatment of degenerative diseases of the lumbar spine.

An analysis of clinical application effects of 3d-printed act titanium trabecular intervertebral fusion cage in posterior lumbar interbody fusion (PLIF).

To compare the clinical effects of applying a 3D-printed ACT titanium trabecular intervertebral fusion cage and a Polyetheretherketone (PEEK) cage in posterior lumbar interbody fusion (PLIF). This was a clinical comparative study. Forty patients with degenerative lumbar diseases admitted at The Second People's Hospital of Dalian from January 2020 to December 2021 were selected and divided into an observation group (3D cage) and a control group (PEEK cage) using the random number table method, with each group of 20 cases. The visual analogue scale (VAS) scores, Japanese Orthopaedic Association (JOA) scores, Cobb angles at fusion segments, intervertebral height and intervertebral fusion situations of the patients between the groups were compared. No significant differences were found in their operation time, intraoperative blood losses and operation related complications(p>0.05). In terms of postoperative VAS and JOA scores in both groups, they are all significantly improved compared with those before the operation, and their differences are also statistically significant(p<0.05). However, no statistical significance exists in inter-group differences(p>0.05). Postoperative Cobb angles and intervertebral height of patients in both groups are considerably bettered compared with those before the operation. Their differences show statistical significance(p<0.05), while inter-group differences are proved to be not statistically significant(p>0.05). Applying a 3D-printed ACT titanium trabecular intervertebral fusion cage or PEEK cage in PLIF has the potential to improve clinical symptoms of patients with degenerative lumbar diseases, and restore the Cobb angle and intervertebral height. 3D-printed ACT titanium trabecular intervertebral fusion cage can accelerate intervertebral fusion without increasing operation related complications.

Best practices guidelines in the postoperative management of patients who underwent cervical and lumbar fusions.

There is a lack of standardization in spine surgery in particular, as relates to postoperative care for the most common spine procedures such as cervical and lumbar fusions. The goal of this study was to develop a standardized postoperative treatment protocol for common spine procedures such as cervical and lumbar fusion to reduce unnecessary visits, imaging studies, and create a standard for all spine surgeons to adhere while maintaining quality. We developed a best practices protocol (BPP) for postoperative spine care for anterior cervical diskectomy and fusion (ACDF) and posterior lumbar interbody fusion (PLIF). We compared outcome to retrospective controls (pre-BPP) and a national database [Quality Outcomes Database (QOD)/American Spine Registry (ASR)]. Pre-BPP retrospective controls (n=1,010) were compared to patients enrolled in BPP (n=750). BPP reduced postoperative visits (POV) from 2,201 to 1,061 (52%). Total additional imaging studies computed tomography (CT) and magnetic resonance imaging (MRI) beyond standard X-ray were reduced from 192 studies to 57 (70%); 53% for lumbar fusion and 67% for cervical fusion. Comparing pre-BPP to BPP groups for complications, the number of adverse events was reduced by 52% overall; 45% for lumbar fusion, and 62% for cervical fusion. A subset of BPP patients (n=450) with available data were compared to a national registry QOD and ASR where lumbar and cervical fusion patients showed comparable less lengths of stay, lower 3-month complication rates and lower readmission rates. This is one of the first studies to standardize postoperative spine care as a first step towards creating uniformly accepted models for value-based care (VBC) in spine surgery.

Biomechanical Effects of Titanium Alloy Based Single versus Dual Cage Fusion Devices

Degenerative disc disease is an increasing problematic complication following lumbar fusion surgeries. Posterior lumbar interbody fusion (PLIF) is a well-established surgical method for spine stability following intervertebral disc removal. The position and number of titanium cages in PLIF are remain contingent on individual surgeon experience. Thus, a systemic investigation of the efficacy of titanium single mega cage versus two cages in treating degenerative lumbar spinal diseases is imperative. A biomechanical study was aimed to compare the stability achieved in PLIF through interbody reconstruction using a single mega cage (32 mm) Vs. a dual cage (22 mm). Normal intact finite element model of L3–L4 was developed based on computed tomography images from a healthy 27-year-old male volunteer. The study tested the intact model (Model A) and its surgically operated counterparts using four PLIF implantation methods: single transverse cage (Model B), single transverse cage with bone graft (Model C), dual transverse cage (Model D), and dual transverse cage with bone graft (Model E). Combined loads simulating physiological motions—flexion, extension, axial rotation, and lateral bending —were applied across all loading directions. The assessment includes all model range of motion (ROM), micromotion between the cage and endplate, and stress on the cage and internal fixation system (screw and rod). The ROM between Models B, C, D and E were consistently reduced by over 71% compared to intact Model A under all motion scenarios. Model D exhibited the highest peak stress of 115 MPa on the cage during flexion, surpassing Model C and E (Flexion) by fourfold. Model E demonstrated the lowest cage stress (20 MPa) during extension, outperforming the other models. Notably, Model E exhibited minimal endplate stress (2 MPa), cage stress (21 MPa), micromotion (13 µm) during extension, and screw-rod stress (56 MPa) during flexion, making it superior to other implantation methods. In the context of PLIF, Model E showed enhanced biomechanical stability, reducing ROM, stress on the endplates, cage, screw-rod system and micromotion. Alternatively, Model C may be a viable alternative in standard PLIF, especially in cases with limited intervertebral space, providing efficient clinical outcomes with shorter operative times and reduced costs and ease of implantation. Also, this computational study provides valuable understandings into optimizing cage implantation strategies for improved outcomes during PLIF.

Contrasted the clinical and radiological results of patients receiving cage-based bone grafting with PLIF surgical treatment that included bone grafting

Aims: Posterior lumbar interbody fusion (PLIF) is frequently used to treat spinal instabilities that can cause neurological symptoms, leg pain and low back pain including lumbar stenosis, degenerative disc disease and spondylolisthesis in which one vertebra slips over another. This study aimed to compare the clinical and radiographic outcomes of PLIF for degenerative L4 unstable grade III spondylolisthesis using bone grafts and cage bone grafts. Methods: Between from September 2021 to August 2023, 30 patients with degenerative lumbar spine disorders were selected based on the inclusion and exclusion criteria for PLIF. Results: We enrolled 30 patients and divided them into 15 groups (bone graft group I and Cage bone graft group II). The follow-up period was 2 years. Low back pain and leg function of the Japanese Orthopaedic Association (JOA) score showed significant improvement (p &lt;0.005) at 3 months and at the final postoperative (62.1±5.5, 602±5.1) in both groups. The fusion rate was 93% in group I and 83% in group II. Radiological evaluation showed significant changes in slip angle, disc height, lumbar lordosis and translational motion from preoperative to final follow-up in both groups. A computer tomography (CT) revealed bilateral spondylolysis, disc collapse and anterolisthesis of the fifth lumbar vertebra. These results were verified by magnetic resonance imaging (MRI). There was no spinal canal stenosis. Conclusion: This finding suggests that successful clinical and radiological results can be obtained with PLIF surgery using either a cage with bone or a bone graft alone. The surgeon's inclination, the particular state of the patient and the resources at hand may influence which of the two approaches is used. The results showed no statistically significant difference between the two groups in terms of clinical and radiological outcomes (bone graft and cage with bone graft). This indicates that neither strategy showed a clear edge over the others in the criteria under study and both were equally successful in yielding favorable outcomes.

Effect of intervertebral bone graft area on the effect of single-level posterior lumbar decompression and bone graft fusion

To study the effect of intervertebral grafting area on the effect of single segment lumbar posterior decompression and intervertebral bone grafting fusion. The clinical data of 52 patients who underwent single-segment lumbar posterior decompression pedicle internal fixation and bone grafting fusion from January 2020 to December 2022 were retrospective reviewed. The area of the intervertebral bone graft was measured one week postoperatively using Computed Tomography (CT), and based on the ratio of the bone graft area to the average area of the endplates, the patients were divided into three groups:17 cases in group A(the intervertebral bone graft area did not exceed the area of one pedicle) included 9 males and 8 females with an average age of (56.0±11.5) years old;15 cases in group B(the intervertebral bone graft area exceeded one pedicle but did not reach the opposite pedicle) included 10 males and 5 females with an average of (52.0±14.0) years old; 20 cases in group C (the intervertebral bone graft area exceeded the opposite pedicle) included 12 males and 8 females with an average of (49.5±12.8) years old. X-rays and CT scans were performed at 3, 6, 12 months, and the final follow-up postoperatively, the interbody fusion Brantigan scores, pain visual analogue scale (VAS), and Oswestry Disability Index (ODI) at each follow-up were recorded. The gender, age, and surgical segments showed no significant differences among three groups(P>0.05). There was also no significant difference in the preoperative VAS and ODI among three groups (P>0.05). All patients of three groups were followed up from 12 to 36 months. Compared with preoperative, VAS and ODI scores of three groups showed significant improvement at 1 week postoperatively and the final follow-up (P<0.05). Compared with preoperative measurements, the height of the intervertebral space was restored at 1 week postoperatively in three groups;at the final follow-up, the loss of height in the intervertebral space was less in groups B and C, and the height of the intervertebral space in group B and C was significantly higher than in group A(P<0.05). The modified Brantigan scores at 3 and 6 months postoperatively were significantly higher in group C than in groups A and B (P<0.05);at 12 months postoperatively, the scores in groups B and C were significantly higher than in group A(P<0.05);however, at the final follow-up, there was no significant difference in the modified Brantigan scores among three groups(P>0.05). The bone graft fusion rate in group C was significantly higher than in groups A and B at 3 months postoperatively(P<0.05);at 6 and 12 months postoperatively, the fusion rates in groups B and C were significantly higher than in group A(P<0.05);at the final follow-up, the fusion rate in group A was still lower than in groups B and C, but the difference among three groups was not significant(P>0.05). Single segment posterior lumbar decompression and interbody fusion surgery can significantly improve the clinical symptoms of patients with lumbar degenerative related diseases. However, as the proportion of bone grafting area increases, the early bone grafting fusion rate and fusion score of patients are significantly improved.

Anatomically and mechanically conforming patient-specific spinal fusion cages designed by full-scale topology optimization

Cage subsidence after instrumented lumbar spinal fusion surgery remains a significant cause of treatment failure, specifically for posterior or transforaminal lumbar interbody fusion. Recent advancements in computational techniques and additive manufacturing, have enabled the development of patient-specific implants and implant optimization to specific functional targets. This study aimed to introduce a novel full-scale topology optimization formulation that takes the structural response of the adjacent bone structures into account in the optimization process. The formulation includes maximum and minimum principal strain constraints that lower strain concentrations in the adjacent vertebrae. This optimization approach resulted in anatomically and mechanically conforming spinal fusion cages. Subsidence risk was quantified in a commercial finite element solver for off-the-shelf, anatomically conforming and the optimized cages, in two representative patients. We demonstrated that the anatomically and mechanically conforming cages reduced subsidence risk by 91% compared to an off-the-shelf implant with the same footprint for a patient with normal bone quality and 54% for a patient with osteopenia. Prototypes of the optimized cage were additively manufactured and mechanically tested to evaluate the manufacturability and integrity of the design and to validate the finite element model.

Adjacent segment degeneration at a minimum 2-year follow-up after posterior lumbar interbody fusion: the impact of sagittal spinal proportion: a retrospective case series.

A retrospective cohort study. To investigate the sagittal plane configuration of the entire spine and its association with the risk of adjacent segment degeneration (ASD) after posterior lumbar interbody fusion (PLIF). Although PLIF has demonstrated satisfactory clinical outcomes, it is associated with ASD. However, the geometric mechanical changes that contribute to the occurrence of ASD are not well characterized. Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group. All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12-L1 disc) (69.0% vs. 38.6%). The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12-L1.

A novel technique for posterior lumbar interbody fusion to obtain a good local lordosis angle: anterior-release posterior lumbar interbody fusion.

Herein, we describe a novel posterior lumbar interbody fusion (PLIF) technique with annulus fibrosus (AF) release and the use of expandable cages (called "anterior-release PLIF" [ARPLIF]). In this technique, posterior column osteotomy (PCO) and AF release provide excellent intervertebral mobility. AF release involves circumferentially peeling off the AF above or below the endplate between the fixed vertebrae under radiographic guidance without cutting the AF and anterior longitudinal ligament. Subsequently, high-angle variable-angle expandable cages are used to simultaneously expand both sides before inserting the percutaneous pedicle screws and correcting to achieve good local lumbar lordosis. PCO and AF release achieve excellent intervertebral mobility. Intervertebral mobility and simultaneous expansion of both cages disperse the force on the endplates, reducing cage subsidence, and the high-angle cages facilitate high intervertebral angle creation. The novel ARPLIF intervertebral manipulation technique can promote good local lumbar lordosis formation.

Minimally invasive far lateral tubular microdiscectomy: surgical technique and case series of 176 patients.

Far lateral (extraforaminal) disc herniations comprise approximately 10% of symptomatic lumbar disc herniations. They represent operative challenges due to accessibility and surgical unfamiliarity. Surgical strategies in the past have included open discectomy and posterior lumbar interbody fusion. Tubular microdiscectomies have gained traction due to their minimally invasive advantages, including reduced morbidity, pain and length of hospital stay. We report our retrospective single institution consecutive case series of tubular far lateral microdiscectomies. One hundred and seventy-six patients were operated on over an eight-year period. Clinical outcomes were assessed after institutional ethics approval. We additionally describe our surgical technique with an illustrative video case. Over a mean follow-up of 21 weeks, 77% of patients had good or excellent clinical outcomes according to the MacNab criteria. 12% of patients underwent reoperation at the index level for symptom recurrence or persistence. Mean length of hospital stay was 1.3 days. There was a 1% rate of both postoperative haematoma and infection. Mean operation duration was 86minutes. This case series represents the largest currently reported in the literature. Minimally invasive microdiscectomies performed through tubes allow for precise localisation, reduced tissue disruption and favourable clinical outcomes. Our results appear consistent with a review of the literature, demonstrating the safety and efficacy of this approach.

P300. The impact of sarcopenia and gluteal muscle index on clinical outcomes in posterior lumbar interbody fusion surgery: a prospective cohort study

P300. The impact of sarcopenia and gluteal muscle index on clinical outcomes in posterior lumbar interbody fusion surgery: a prospective cohort study

Vertebral Endplate Cavities (VEC) with titanium cages in posterior lumbar interbody fusion (PLIF).

Vertebral endplate cavities (VEC) have been reported with the use of Ti cages. Only few articles have recently demonstrated unfavorable radiographic changes in the form of cysts or cavities which may predispose to nonunion. The aim was to assess the prevalence of VEC in posterior lumbar interbody fusion (PLIF) using Titanium (Ti) cages, and to estimate their impact on fusion. The term "cavity" was used to describe the endplate changes. CT analysis of the VEC and fusion status following PLIFs with Ti cages was conducted by two observers. VEC were assessed according to the size, multiplicity, location, and presence of sclerosis. 42 consecutive patients with surgeries conducted on 52 levels were enrolled. There were 20 males and 22 females. The mean age was 43.6 ±10.89 years. The mean follow-up was 20.85±8.49 months. Definite union was seen in 48 levels (92.3%) by observer 1 and in 40 levels (76.9%) by observer 2. The strength of agreement was moderate. The presence of VEC was observed in 9 levels (17.3%) by observer 1 and in 12 levels (23.1%) by observer 2. The strength of agreement was moderate. The majority of VEC in the endplates were <5mm. The strength of agreement was high. The strength of agreement for location and multiplicity were moderate. The VEC was significantly correlated with the fusion status. Our study confirmed that VEC were observed following Ti cage placement after PLIF procedures. They tend to be small and might be associated with non-union. Furthermore, it reflected the limited inter-rater reliability of the assessment of both the fusion status and VEC morphology after Ti PLIF cage placement.

Cost-effectiveness of posterior lumbar interbody fusion and/or transforaminal lumbar interbody fusion for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes Database study.

Posterior lumbar interbody fusion (PLIF) and/or transforaminal lumbar interbody fusion (TLIF), referred to as "PLIF/TLIF," is a commonly performed operation for lumbar spondylolisthesis. Its long-term cost-effectiveness has not been well described. The aim of this study was to determine the 5-year cost-effectiveness of PLIF/TLIF for grade 1 degenerative lumbar spondylolisthesis using prospective data collected from the multicenter Quality Outcomes Database (QOD). Patients enrolled in the prospective, multicenter QOD grade 1 lumbar spondylolisthesis module were included if they underwent single-stage PLIF/TLIF. EQ-5D scores at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were used to calculate gains in quality-adjusted life years (QALYs) associated with surgery relative to preoperative baseline. Healthcare-related costs associated with the index surgery and related reoperations were calculated using Medicare reimbursement-based cost estimates and validated using price transparency diagnosis-related group (DRG) charges and Medicare charge-to-cost ratios (CCRs). Cost per QALY gained over 60 months postoperatively was assessed. Across 12 surgical centers, 385 patients were identified. The mean patient age was 60.2 (95% CI 59.1-61.3) years, and 38% of patients were male. The reoperation rate was 5.7%. DRG 460 cost estimates were stable between our Medicare reimbursement-based models and the CCR-based model, validating the focus on Medicare reimbursement. Across the entire cohort, the mean QALY gain at 60 months postoperatively was 1.07 (95% CI 0.97-1.18), and the mean cost of PLIF/TLIF was $31,634. PLIF/TLIF was associated with a mean 60-month cost per QALY gained of $29,511. Among patients who did not undergo reoperation (n = 363), the mean 60-month QALY gain was 1.10 (95% CI 0.99-1.20), and cost per QALY gained was $27,591. Among those who underwent reoperation (n = 22), the mean 60-month QALY gain was 0.68 (95% CI 0.21-1.15), and the cost per QALY gained was $80,580. PLIF/TLIF for degenerative grade 1 lumbar spondylolisthesis was associated with a mean 60-month cost per QALY gained of $29,511 with Medicare fees. This is far below the well-established societal willingness-to-pay threshold of $100,000, suggesting long-term cost-effectiveness. PLIF/TLIF remains cost-effective for patients who undergo reoperation.

Influence of facetectomy, cross-link augmentation, and interbody procedure on progression of bone fusion in single-level posterior lumbar interbody fusion using the long cortical bone trajectory technique.

When using the cortical bone trajectory (CBT) technique, two technical countermeasures are recommended to promote bone fusion: taking a long CBT screw path directed more anteriorly and improving the stability of the spinal construct by facet joint preservation, cross-link augmentation, and rigid anterior interbody reconstruction. However, there has been no report on how these surgical procedures, which are heavily dependent on the surgeon's preference, contribute to successful bone fusion. The aim of the present study was to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion, with a particular focus on the involvement of surgical procedures. A total of 167 consecutive patients with L4 degenerative spondylolisthesis who underwent single-level posterior lumbar interbody fusion at L4-5 using the long CBT technique were included (mean follow-up 42.8 months). Bone fusion was assessed to identify factors contributing to the time to achieve bone fusion. Investigated factors were 1) age, 2) sex, 3) BMI, 4) bone mineral density, 5) intervertebral mobility, 6) screw depth in the vertebra, 7) extent of facetectomy, 8) cross-link augmentation, 9) cage material, 10) cage design, 11) number of cages, and 12) contact area of cages with the vertebral endplate. The bone fusion rate was 89.2% at 2 years postoperatively and 95.8% at the last follow-up, with a mean period to bone fusion of 16.6 ± 9.6 months. Multivariate regression analysis revealed that age (standardized regression coefficient [β] = 0.25, p = 0.002), female sex (β = -0.22, p = 0.004), and BMI (β = 0.15, p = 0.045) were significant independent factors affecting the time to achieve bone fusion. There was no significant effect of surgical procedures (p ≥ 0.364). This is the first study to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion. Patient factors such as age, sex, and BMI affected the progression of bone fusion, and surgical factors had only weak effects.

Outcome of Posterior Lumbar Interbody Fusion (PLIF) with Cage and Bone Graft in The Treatment of Degenerative Lumbar Spinal Canal Stenosis

Introduction: Posterior lumbar interbody fusion (PLIF) is a reliable treatment option for patients with Lumbar canal stenosis &amp; spondylolisthesis; providing spinal stabilization in a balanced alignment with the disc space height restored and with the neural elements being decompressed mechanically. The titanium cages provided immediate stability to spinal levels, restoration of the disc space and neuro-foraminal area, and an increased surface area leading to successful fusion. Materials and Methods: This prospective study was carried out at the Department of Orthopedic Surgery at DMCH, Dhaka within the defined period. All the data were compiled and sorted properly and the quantitative data was analyzed statistically by using Statistical Package for Social Science. The results were expressed as percentage and mean ± SD and p&lt;0.05 was considered as the level of significant. Result: Mean age of the study population was 51.32±8.29 with a female: male ratio 1.6 :1 where maximum patient was housewife (57.14%). 60.72% patients had only single level involvement while 39.28% patients had multi-level involvement. Mean VAS score reduced significantly at final follow-up (6.55±0.66 to 2.29±0.46 for back pain and 6.59±0.65 to 1.21±0.42 for leg pain. Mean ODI score decreased significantly from 56.71±3.09 to 15.82±3.46 at final follow-up. Radiologically Grade-I fusion achieved in 89.28% cases. Overall functional outcome was excellent (89.29%) &amp; good (7.14%) according to Modified Macnab criteria. Conclusion: Posterior lumbar interbody fusion (PLIF) with cage and bone graft in the treatment of degenerative lumbar spinal canal stenosis provides excellent neurological and functional outcome and fusion rate at final follow-up. Medicine Today 2024, Vol.36 (2): 72-75

Usability of a novel Hounsfield units measurement procedure to quantify intercorporal bone graft remodeling in patients after posterior lumbar interbody fusion: a case series

BackgroundThere is a lack of knowledge about the biological process of intercorporal bone graft remodeling after posterior lumbar interbody fusion surgery and whether this process is associated with changes in back pain and intercorporal fusion status. As an alternative to the commonly used but unreliable fusion criteria, Hounsfield units can be used to quantify biological activity and changes in bone mineral content. However, studies assessing Hounsfield units conducted to date do not provide sufficient details about how the bone grafts were segmented to measure the Hounsfield units to allow for replication, and did not assess individual patient trends in graft changes over time. Using the data of nine patients after posterior lumbar interbody fusion, a novel Hounsfield units measurement procedure was developed and used to explore its usability to quantify the bone graft remodeling process.Case detailsWe report a case series of nine patients (six male, three female, mean age 64 years, all Caucasian) who all had computed tomography scans performed at 1 and 2 years after posterior lumbar interbody fusion surgery. Overall, seven out of the nine (78%) cases had a 3–41% increase in their bone grafts’ Hounsfield units between 1 and 2 years after surgery. The cases showed large interindividual variability in their Hounsfield units values over time, which coincided with varying levels of back pain and intercorporal fusion status.ConclusionThe Hounsfield units measurement procedure used for this case series may be useful to quantify intercorporal bone graft remodeling in patients after posterior lumbar interbody fusion, and may be used as an adjunct diagnostic measure to monitor bone graft remodeling over time. Future research is warranted to explore how to interpret bone graft Hounsfield units-values and Hounsfield units trajectories in light of clinical variables or intercorporal fusion status.

Minimally Invasive versus Traditional Surgery: Efficacy of PELD and PLIF in Treating Pyogenic Spondylodiscitis.

BACKGROUND Pyogenic spondylodiscitis is infection of the intervertebral disc or discs and the adjacent vertebrae. This retrospective study aimed to compare the effectiveness of percutaneous endoscopic lumbar debridement (PELD) versus posterior lumbar interbody fusion (PLIF) in 40 patients with pyogenic spondylodiscitis (PSD). MATERIAL AND METHODS Medical records of patients who underwent PELD (n=18) or PLIF (n=22) for PSD between 2018 and 2023 were reviewed. The recorded outcomes encompassed surgical duration, intraoperative blood loss, Oswestry Disability Index (ODI) measurements, Visual Analog Scale (VAS) assessments, C-reactive protein (CRP) levels, duration of hospitalization, erythrocyte sedimentation rate (ESR), American Spinal Injury Association (ASIA) grading, lumbar sagittal parameters, and the incidence of complications. RESULTS The PELD group had shorter surgical duration, less intraoperative blood loss, and shorter length of hospital stay compared to the PLIF group (P<0.01). At the last follow-up, both groups had significant improvement in ESR, CRP levels, and ASIA classification (P<0.001), but there was no significant difference between the 2 groups (P>0.05). The PELD group had lower ODI and VAS ratings at 1 month and 3 months, respectively (P<0.01). The PLIF group had significant improvements in intervertebral space height and lumbar lordosis angle (P<0.01). CONCLUSIONS Both PLIF and PELD surgical approaches demonstrate adequate clinical efficacy in the treatment of monosegmental PSD. PLIF can better ensure more spinal stability than PELD, but PELD offers advantages such as reduced minimal surgical trauma, shorter operative duration, and faster recovery after surgery.

Biomechanical effects of posterior lumbar interbody fusion with vertical placement of pedicle screws compared to traditional placement.

The pedicle screw technique is widely employed for vertebral body fixation in the treatment of spinal disorders. However, traditional screw placement methods require the dissection of paraspinal muscles and the insertion of pedicle screws at specific transverse section angles (TSA). Larger TSA angles require more force to pull the muscle tissue, which can increase the risk of surgical trauma and ischemic injury to the lumbar muscles. To study the feasibility of zero-degree TSA vertical pedicle screw technique in the lumbosacral segment. Finite element models of vertebral bodies and pedicle screw-rod systems were established for the L4-S1 spinal segments. A standard axial load of 500 N and a rotational torque of 10 N/m were applied. Simulated screw pull-out experiment was conducted to observe pedicle screw resistance to pull-out, maximum stress, load-displacement ratio, maximum stress in vertebral bodies, load-displacement ratio in vertebral bodies, and the stress distribution in pedicle screws and vertebral bodies. Differences between the 0-degree and 17-degree TSA were compared. At 0-degree TSA, the screw pull-out force decreased by 11.35% compared to that at 17-degree TSA (P < 0.05). At 0-degree and 17-degree TSA, the stress range in the screw-rod system was 335.1-657.5 MPa and 242.8-648.5 MPa, separately, which were below the fracture threshold for the screw-rod system (924 MPa). At 0-degree and 17-degree TSA, the stress range in the vertebral bodies was 68.45-78.91 MPa and 39.08-72.73 MPa, separately, which were below the typical bone yield stress range for vertebral bodies (110-125 MPa). At 0-degree TSA, the load-displacement ratio for the vertebral bodies and pedicle screws was slightly lower compared to that at 17-degree TSA, indicating slightly lower stability (P < 0.05). The safety and stability of 0-degree TSA are slightly lower, but the risks of screw-rod system fracture, vertebral body fracture, and rupture are within acceptable limits.

Novel MRI-Based Pedicle Bone Quality Score Independently Predicts Pedicle Screw Loosening after Degenerative Lumbar Fusion Surgery.

To introduce and evaluate an MRI-based PBQ score to determine its effectiveness in predicting pedicle screw loosening following lumbar fusion surgery. The retrospective study analyzed 244 patients who underwent posterior lumbar interbody fusion (PLIF) with pedicle screws between December 2017 and December 2021, with CT and MRI imaging before surgery. Data collected included patient demographics and preoperative radiological data. Radiographic screw loosening was measured at 12 months postoperatively. Clinical assessments included pain visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. The PBQ score was measured using MRI scans. We use univariate analysis for preliminary screening of the risk factors of screw loosening. Subsequent analysis involved multivariate logistic regression to identify independent predictive factors for screw loosening. We constructed the receiver operating characteristic (ROC) curve to ascertain the discriminative capacity of the PBQ score. The area under the curve (AUC) quantified its predictive accuracy. Additionally, we evaluated the association between PBQ score and screw loosening using Spearman's correlation analysis. Overall, 244 patients who underwent PLIF with pedicle screw fixation participated in this study, including 35 in the loosening group and 209 in the non-loosening group. PBQ score in the loosening group was significantly higher than that in the non-loosening group. On multivariate logistic regression, the higher PBQ score (OR = 8.481, 95% CI: 3.158-22.774; p < 0.001) and the lower mean Hounsfield unit (HU) value of L1-4 (OR = 0.967, 95% CI 0.951-0.984; p < 0.001) were the variables that significantly predicted screw loosening. The AUC for the PBQ score and HU value were 0.751 (95% CI: 0.673-0.828) and 0.702 (95% CI: 0.612-0.791). The PBQ score optimal cutoff to differentiate patients with loosening and with non-loosening was calculated as 3.045 with a sensitivity of 85.7% and specificity of 76.9%, while the optimal cutoff of the HU value was 151.5 with a sensitivity of 64.6% and specificity of 89.5%. The association between the PBQ score and the propensity for lumbar pedicle screw loosening was found to be substantial. As a predictive measure, the PBQ score outperformed the HU value in forecasting the likelihood of screw loosening post-posterior lumbar fusion.

Full-Endoscopic Posterior Lumbar Interbody Fusion: A Review and Technical Note

Remarkable innovations in spinal endoscopic surgery have broadened its applications over the past 20 years. Full-endoscopic fusions have been widely reported, and several full-endoscopic approaches for interbody fusion have been published. In general, full-endoscopic lumbar interbody fusion (LIF) is called Endo-LIF, and facet-preserving endo-LIF through the transforaminal route is called trans-Kambin’s triangle LIF, which has a relatively longer history than facet-sacrificing endo-LIF via the posterolateral route. Both approaches can reduce intraoperative and postoperative bleeding. However, there is a higher risk of subsidence and exit nerve root injury. There is no direct decompression in either of the interbody fusions, and additional decompression is required if there is severe lumbar bony canal stenosis. However, the posterior interlaminar approach, which is a well-known standard in full-endoscopic spine surgery, has rarely been applied in the field of endoscopic lumbar fusion surgery. Full-endoscopic posterior LIF (FE-PLIF) via an interlaminar approach can accomplish direct decompression of bony canal stenosis and safe interbody fusion. FE-PLIF via an interlaminar approach demonstrated a longer operation time, less blood loss, and shorter hospitalization duration than minimally invasive transforaminal LIF. FE-PLIF, which can accomplish direct decompression for bony spinal canal stenosis, is superior to other Endo-LIFs. However, FE-PLIF requires technical dexterity to improve efficiency and reduce technical complexity.