MRI-based endplate bone quality score predicts cage subsidence following oblique lumbar interbody fusion.

BACKGROUND CONTEXT: Cage subsidence is a common complication after lumbar interbody fusion surgery, with low bone mineral density (BMD) being a significant risk factor. ໿Endplate bone quality (EBQ) obtained from clinical MRI scans has been deemed reliable in determining regional BMD. However, the association between EBQ score and cage subsidence following oblique lumbar interbody fusion (OLIF) has not been clearly established. PURPOSE: This study aims to assess the relationship between EBQ score and cage subsidence in patients who underwent single-level OLIF. STUDY DESIGN/SETTING: A retrospective study. PATIENT SAMPLE: The study included adults with degenerative spinal conditions who underwent single-level OLIF at our institution. OUTCOME MEASURES: Cage subsidence, disc height, EBQ score, fusion rate. METHODS: This retrospective study analyzed data from patients who underwent single-level OLIF surgery at our institution between October 2017 and August 2022. Postoperative CT scans were used to measure cage subsidence, while the EBQ score was calculated using preoperative non-contrast T1-weighted MRI. To determine the predictive ability of the EBQ score, receiver operating characteristic (ROC) curve analysis was conducted. Additionally, univariable and multivariable logistic regression analyses were performed. RESULTS: In this study, a total of 88 patients were included and followed up for an average of 15.8 months. It was observed that 32.9% (n=29/88) of the patients experienced cage subsidence. The post-surgery disc height was significantly higher in patients who experienced subsidence compared to those who did not. The mean EBQ scores for patients with non-subsidence and subsidence were 2.31±0.6 and 3.48±1.2, respectively, and this difference was statistically significant. The ROC curve analysis showed that the AUC for the EBQ score was 0.811 (95% CI: 0.717-0.905). The most suitable threshold for the EBQ score was determined to be 2.318 (sensitivity: 93.1%, specificity: 55.9%). Additionally, the multivariate logistic regression analysis revealed a significant association between a higher EBQ score and an increased risk of subsidence (odds ratio [OR]=6.204, 95% CI=2.520-15.272, p<.001). CONCLUSIONS: Our findings indicate that higher preoperative EBQ scores are significantly linked to cage subsidence following single-level OLIF. Preoperative measurement of MRI can serve as a valuable tool in predicting cage subsidence.

Recent Advances in Nanotechnology-Based Strategies for Bone Tuberculosis Management.

Bone tuberculosis, an extrapulmonary manifestation of tuberculosis, presents unique treatment challenges, including its insidious onset and complex pathology. While advancements in anti-tubercular therapy have been made, the efficacy is often limited by difficulties in achieving targeted drug concentrations and avoiding systemic toxicity. The intricate bone structure and presence of granulomas further impede effective drug delivery. Nano-drug delivery systems have emerged as a promising alternative, offering the enhanced targeting of anti-tubercular drugs. These systems, characterized by their minute size and adaptable surface properties, can be tailored to improve drug solubility, stability, and bioavailability, while also responding to specific stimuli within the bone TB microenvironment for controlled drug release. Nano-drug delivery systems can encapsulate drugs for precise delivery to the infection site. A significant innovation is their integration with prosthetics or biomaterials, which aids in both drug delivery and bone reconstruction, addressing the infection and its osteological consequences. This review provides a comprehensive overview of the pathophysiology of bone tuberculosis and its current treatments, emphasizing their limitations. It then delves into the advancements in nano-drug delivery systems, discussing their design, functionality, and role in bone TB therapy. The review assesses their potential in preclinical research, particularly in targeted drug delivery, treatment efficacy, and a reduction of side effects. Finally, it highlights the transformative promise of nanotechnology in bone TB treatments and suggests future research directions in this evolving field.

Gas-Source Comparison and Hydrocarbon Generation and Expulsion Histories of the Main Source Rocks of the Middle Jurassic Shaximiao Formation, Western Sichuan Basin.

With the discovery and exploration of tight sandstone gas reservoirs in the Sichuan Basin, the Middle Jurassic Shaximiao Formation has gradually become the focus of exploration. However, the gas source of the Shaximiao Formation in the Western Sichuan Basin is still controversial, and research on the hydrocarbon generation and expulsion histories of the primary source rocks lags behind, which restricts the study of tight sandstone gas reservoir dynamics within the Shaximiao Formation in the Western Sichuan Basin and further affects the oil and gas exploration process. This paper, utilizing geochemical parameters, including 82 natural gas components and 68 carbon isotopes, conducted an investigation into the origin identification of natural gas and gas-source comparisons within the Shaximiao Formation in the Western Sichuan Basin. By utilizing basin modeling technology, we reconstructed the histories of hydrocarbon generation and expulsion of the primary source rocks and identified the potential exploration areas. The findings indicate that the natural gas within the Shaximiao Formation in the Western Sichuan Basin is characterized by a typical high-maturity wet gas-dry gas reservoir. It is a thermogenic coal-type gas produced by kerogen cracking, and the gas source is primarily type-III kerogen. The main source of natural gas is the coal-measure source rock of the Upper Triassic Xujiahe 5 Formation, which has mainly experienced two stages of increasing maturity, characterized by "two stages of gas generation and one stage of gas expulsion". The hydrocarbon generation and expulsion histories for the source rocks within the Xujiahe 5 Formation is shown as follows: the source rocks of the Xujiahe 5 Formation reached the hydrocarbon generation threshold by the end of the Early Jurassic and peaked in hydrocarbon generation by the end of the Late Jurassic, and then the natural gas migrated to the paleostructural highs of the Shaximiao Formation to form the paleo-gas reservoir. From the end of the Early Cretaceous, the paleo-gas reservoir underwent adjustments and transformations to evolve into the present-day gas reservoir. The source rocks exhibit substantial potential for the forming of large-medium and extralarge gas fields, with favorable exploration zones concentrated in the southern and central portions of the study area. The research findings can provide a scientific foundation for the next exploration and deployment of natural gas resources within the Shaximiao Formation in the Western Sichuan Basin.

Comparative evaluation of multi-fold rib and structural iliac bone grafts in single-segment thoracic and thoracolumbar spinal tuberculosis: clinical and radiological outcomes.

OBJECTIVE: To compare clinical and radiological outcomes of multi-fold rib and structural iliac bone grafts, the primary autologous graft techniques in anterolateral-only surgery for single-segment thoracic and thoracolumbar spinal tuberculosis. METHODS: This retrospective study included 99 patients treated from January 2014 to March 2022, categorized into 64 with multi-fold rib grafts (group A) and 35 with structural iliac bone grafts (group B). Outcomes assessed included hospital stay, operation time, intraoperative blood loss, postoperative drainage, complications, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the Visual Analog Scale (VAS) for pain, the Oswestry Disability Index (ODI), bone fusion time, and the American Spinal Injury Association (ASIA) impairment scale grade. Segmental kyphotic angle and intervertebral height were measured radiologically before surgery and follow-up. RESULTS: The mean follow-up was 63.50 ± 26.05 months for group A and 64.97 ± 26.43 months for group B (P > 0.05). All patients had achieved a clinical cure. Group A had a shorter operation time (P = 0.004). Within one week post-surgery, group B reported higher VAS scores (P < 0.0001). Neurological performance and quality of life significantly improved in both groups. No significant differences were observed in segmental kyphotic angle and intervertebral height between the groups pre- and postoperatively (P > 0.05). However, group A showed a greater segmental kyphotic angle at the final follow-up, while group B had better maintenance of kyphotic angle correction and intervertebral height (P < 0.05). Bone fusion was achieved in all patients without differences in fusion time (P > 0.05). CONCLUSIONS: Multi-fold rib grafts resulted in shorter operation times and less postoperative pain, while structural iliac bone grafts provided better long-term maintenance of spinal alignment and stability, suggesting their use in cases where long-term outcomes are critical.

The Influence of Screw Positioning on Cage Subsidence in Patients with Oblique Lumbar Interbody Fusion Combined with Anterolateral Fixation.

OBJECTIVES: Cage subsidence (CS) has been reported to be one of the most common complications following oblique lumbar interbody fusion (OLIF). To reduce the incidence of CS and improve intervertebral fusion rates, anterolateral fixation (AF) has been gradually proposed. However, the incidence of CS in patients with oblique lumbar interbody fusion combined with anterolateral fixation (OLIF-AF) is still controversial. Additionally, there is a lack of consensus regarding the optimal placement of screws for OLIF-AF, and the impact of screw placement on the incidence of CS has yet to be thoroughly investigated and validated. The objective of this investigation was to examine the correlation between screw placements and CS and to establish an optimized approach for implantation in OLIF-AF. METHODS: A retrospective cohort study was undertaken. From October 2017 to December 2020, a total of 103 patients who received L4/5 OLIF-AF for lumbar spinal stenosis or spondylolisthesis or degenerative instability in our department were followed up for more than 12 months. Demographic and radiographic data of these patients were collected. Additionally, screw placement related parameters, including trajectory and position, were measured by anterior-posterior X-ray and axial CT. Analysis was done by chi-square, independent t-test, univariable and multivariable binary logistic regression to explore the correlation between screw placements and CS. Finally, the receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of screw placement-related parameters. RESULTS: A total of 103 patients were included, and CS was found in 28 (27.18%) patients. Univariable analysis was firstly performed for each parameter. Next, variables with p-value of <0.05, including bone mineral density (BMD), concave morphology, and screw placement-related parameters were included in the multivariate logistic regression analysis. Significant predictor factors for subsidence were coronal plane angle (CPA) (OR 0.580 ± 0.208, 95% CI 1.187-2.684), implantation point (IP) (L4) (OR 5.732 ± 2.737, 95% CI 1.445-12.166), and IP (L5) (OR 7.160 ± 3.480, 95% CI 1.405-28.683). Furthermore, ROC curves showed that the predictive accuracy of CS was 88.1% for CPA, 77.6% for IP (L4) and 80.9% for IP (L5). CONCLUSIONS: We demonstrate that the trajectory of vertebral screws, including angle and position, was closely related to CS. Inserting screws parallel to each other and as close to the endplate as possible while keeping the cage inside the range of the superior and inferior screws are an optimal implantation strategy for OLIF-AF.

Physiological response and molecular mechanisms against UV-B radiation in Brachionus asplanchnoidis (Rotifera).

Ultraviolet B (UV-B, 280-320 nm) radiation is a major environmental stressor for aquatic organisms on Earth's surface. Its effects on biological systems are well known, but the mechanisms by which organisms respond and adapt to UV-B radiation are still being explored. In this study, we investigated the effects of UV-B radiation on the monogonont rotifer Brachionus asplanchnoidis, focusing on physiological parameters, antioxidant systems, DNA damage, and DNA repair-related molecular mechanism. Our results showed that the LD50 was at 28.53 kJ/m2, indicating strong tolerance to UV-B. However, UV-B radiation caused adverse effects on growth and reproduction, with shortened reproductive period and longevity, decreased fecundity and hatchability, and inhibition of population growth. Biochemical analyses revealed severe oxidative damage and lipid peroxidation, with increased ROS and MDA levels. Activities of antioxidant enzymes were highly induced at low doses but decreased at high doses. DNA damage also occurred in UV-B-exposed rotifers. Furthermore, selected DNA repair-related genes were up-regulated in a dose-dependent manner. These findings provide a comprehensive understanding of the effects of UV-B radiation on rotifers and highlight the importance of considering both ecological and molecular responses in assessing the impact of UV-B radiation on aquatic organisms.

Personalized Interventional Surgery of the Lumbar Spine: A Perspective on Minimally Invasive and Neuroendoscopic Decompression for Spinal Stenosis.

Pain generator-based lumbar spinal decompression surgery is the backbone of modern spine care. In contrast to traditional image-based medical necessity criteria for spinal surgery, assessing the severity of neural element encroachment, instability, and deformity, staged management of common painful degenerative lumbar spine conditions is likely to be more durable and cost-effective. Targeting validated pain generators can be accomplished with simplified decompression procedures associated with lower perioperative complications and long-term revision rates. In this perspective article, the authors summarize the current concepts of successful management of spinal stenosis patients with modern transforaminal endoscopic and translaminar minimally invasive spinal surgery techniques. They represent the consensus statements of 14 international surgeon societies, who have worked in collaborative teams in an open peer-review model based on a systematic review of the existing literature and grading the strength of its clinical evidence. The authors found that personalized clinical care protocols for lumbar spinal stenosis rooted in validated pain generators can successfully treat most patients with sciatica-type back and leg pain including those who fail to meet traditional image-based medical necessity criteria for surgery since nearly half of the surgically treated pain generators are not shown on the preoperative MRI scan. Common pain generators in the lumbar spine include (a) an inflamed disc, (b) an inflamed nerve, (c) a hypervascular scar, (d) a hypertrophied superior articular process (SAP) and ligamentum flavum, (e) a tender capsule, (f) an impacting facet margin, (g) a superior foraminal facet osteophyte and cyst, (h) a superior foraminal ligament impingement, (i) a hidden shoulder osteophyte. The position of the key opinion authors of the perspective article is that further clinical research will continue to validate pain generator-based treatment protocols for lumbar spinal stenosis. The endoscopic technology platform enables spine surgeons to directly visualize pain generators, forming the basis for more simplified targeted surgical pain management therapies. Limitations of this care model are dictated by appropriate patient selection and mastering the learning curve of modern MIS procedures. Decompensated deformity and instability will likely continue to be treated with open corrective surgery. Vertically integrated outpatient spine care programs are the most suitable setting for executing such pain generator-focused programs.

[Development and validation of an automatic diagnostic tool for lumbar stability based on deep learning].

Objective: To develop an automatic diagnostic tool based on deep learning for lumbar spine stability and validate diagnostic accuracy. Methods: Preoperative lumbar hyper-flexion and hyper-extension X-ray films were collected from 153 patients with lumbar disease. The following 5 key points were marked by 3 orthopedic surgeons: L4 posteroinferior, anterior inferior angles as well as L5 posterosuperior, anterior superior, and posterior inferior angles. The labeling results of each surgeon were preserved independently, and a total of three sets of labeling results were obtained. A total of 306 lumbar X-ray films were randomly divided into training (n=156), validation (n=50), and test (n=100) sets in a ratio of 3∶1∶2. A new neural network architecture, Swin-PGNet was proposed, which was trained using annotated radiograph images to automatically locate the lumbar vertebral key points and calculate L4, 5 intervertebral Cobb angle and L4 lumbar sliding distance through the predicted key points. The mean error and intra-class correlation coefficient (ICC) were used as an evaluation index, to compare the differences between surgeons' annotations and Swin-PGNet on the three tasks (key point positioning, Cobb angle measurement, and lumbar sliding distance measurement). Meanwhile, the change of Cobb angle more than 11° was taken as the criterion of lumbar instability, and the lumbar sliding distance more than 3 mm was taken as the criterion of lumbar spondylolisthesis. The accuracy of surgeon annotation and Swin-PGNet in judging lumbar instability was compared. Results: ① Key point: The mean error of key point location by Swin-PGNet was (1.407±0.939) mm, and by different surgeons was (3.034±2.612) mm. ② Cobb angle: The mean error of Swin-PGNet was (2.062±1.352)° and the mean error of surgeons was (3.580±2.338)°. There was no significant difference between Swin-PGNet and surgeons (P>0.05), but there was a significant difference between different surgeons (P<0.05). ③ Lumbar sliding distance: The mean error of Swin-PGNet was (1.656±0.878) mm and the mean error of surgeons was (1.884±1.612) mm. There was no significant difference between Swin-PGNet and surgeons and between different surgeons (P>0.05). The accuracy of lumbar instability diagnosed by surgeons and Swin-PGNet was 75.3% and 84.0%, respectively. The accuracy of lumbar spondylolisthesis diagnosed by surgeons and Swin-PGNet was 70.7% and 71.3%, respectively. There was no significant difference between Swin-PGNet and surgeons, as well as between different surgeons (P>0.05). ④ Consistency of lumbar stability diagnosis: The ICC of Cobb angle among different surgeons was 0.913 [95%CI (0.898, 0.934)] (P<0.05), and the ICC of lumbar sliding distance was 0.741 [95%CI (0.729, 0.796)] (P<0.05). The result showed that the annotating of the three surgeons were consistent. The ICC of Cobb angle between Swin-PGNet and surgeons was 0.922 [95%CI (0.891, 0.938)] (P<0.05), and the ICC of lumbar sliding distance was 0.748 [95%CI(0.726, 0.783)] (P<0.05). The result showed that the annotating of Swin-PGNet were consistent with those of surgeons. Conclusion: The automatic diagnostic tool for lumbar instability constructed based on deep learning can realize the automatic identification of lumbar instability and spondylolisthesis accurately and conveniently, which can effectively assist clinical diagnosis.

Clinical and radiological outcomes of n-HA/PA66 cages in anterior spine reconstruction following total en bloc spondylectomy for tumors.

Objective: This retrospective monocentric study was conducted to evaluate the clinical and radiological outcomes of the nano-hydroxyapatite/polyamide66 (n-HA/PA66) cage in reconstructing the anterior column of the spine following total en bloc spondylectomy (TES). Methods: A cohort of 24 patients, 20 diagnosed with primary malignant tumors and 4 with metastatic malignancies, was selected based on specific inclusion criteria. All were subjected to TES and anterior column reconstruction with the n-HA/PA66 cage from January 2013 to July 2023 at a single institution. Pre-operative embolization was performed on all patients. Documented factors included operation duration, intraoperative blood loss, length of hospital stay, treatment history, and involved level. Mechanical complications and radiological parameters such as the local kyphotic angle (LKA), anterior vertebral height (AVH), posterior vertebral height (PVH), cage subsidence, and bone fusion time were evaluated. Quality of life and neurological function were gauged using tools like the Visual Analog Scale (VAS), Eastern Cooperative Oncology Group (ECOG) performance score, Karnofsky Performance Score (KPS) scale, and American Spinal Injury Association (ASIA) grading. Results: All patients were followed up for 12-127 months, with an average period of 39.71 months. An average operation time of approximately 8.57 h and a blood loss volume of about 1,384 ml were recorded. No instances of tumor recurrence or multiple organ metastases were reported, though recurrence was detected in 2 living patients. Solid fusion was achieved in all patients at a mean time of 6.76 ± 0.69 months. Cage breakage or migration was not observed. Subsidence into the adjacent vertebral bodies was identified in 3 patients but was deemed clinically irrelevant. Significant improvements in VAS, ECOG performance score, KPS scale, and ASIA scores were noted from pre- to post-surgery (P < 0.05). A marked enhancement in the AVH was observed from before surgery to immediately after (P < 0.05). LKA, AVH, and PVH values between postoperative and final follow-up showed no significant variance (P > 0.05). Conclusion: The integration of TES and the n-HA/PA66 cage was found to yield promising clinical and radiological outcomes in anterior column spine reconstruction. The use of this material did not hinder oncological care, including the provision of adjuvant treatments (chemo/radiotherapy), ultimately contributing to the enhanced long-term quality of life for spinal tumor patients.

[Research progress of effect of cage height on outcomes of lumbar interbody fusion surgery].

Objective: To summarize the effect of cage height on outcomes of lumbar interbody fusion surgery and the importance of the cage height selection. Methods: The related literature was widely reviewed to summarize the research progress on the complications caused by inappropriate height of the cage and the methods of selecting cage height. Results: Inappropriate height of the cage can lead to endplate injury, cage subsidence, internal fixation failure, adjacent segmental degeneration, over-distraction related pain, insufficient indirect decompression, instability of operation segment, poor interbody fusion, poor sequence of spine, and cage displacement. At present, the selection of the cage height is based on the results of the intraoperative model test, which is reliable but high requirements for surgical experience and hard to standardize. Conclusion: The inappropriate height of the cage may have an adverse impact on the postoperative outcome of patients. It is important to develop a selection standard of the cage height by screening the related influential factors.

Gait asymmetry of lower extremities reduced immediately after minimally invasive surgery among patients with lumbar disc herniation.

BACKGROUND: Lumbar disc herniation patients with increased pain exhibit greater gait asymmetry in stance time, swing time and single support time. Percutaneous endoscopic lumbar discectomy, as a minimally invasive surgical procedure has been used to treat patients with lumbar disc herniation. The objective of this study was to evaluate the immediate impact of the percutaneous endoscopic lumbar discectomy on gait asymmetry in spatiotemporal and kinetic parameters among lumbar disc herniation patients. METHODS: Marker trajectories and ground reaction forces were measured during walking among 67 lumbar disc herniation patients and 15 healthy controls. Spatiotemporal gait parameters were analyzed via Visual3D. Muscle force and joint contact force were calculated with OpenSim. Gait asymmetry of those parameters were assessed with asymmetry index. FINDINGS: After surgery, gait asymmetry in gait cycle time, step length, peak biceps femoris long head, tensor fasciae latae and rectus femoris muscle forces, and peak hip and knee joint contact forces reduced immediately. Postoperatively, increased gait cycle time and decreased step length were found in the affected side. Moreover, decreased peak biceps femoris long head, tensor fasciae latae and rectus femoris muscle forces, and peak hip joint contact force were observed in the contralateral side. INTERPRETATION: These results suggested compensation strategy that biceps femoris long head, tensor fasciae latae and rectus femoris in the contralateral side were mainly used to compensate the affected side preoperatively in lumbar disc herniation patients, with less compensation between lower limbs after surgery, which may provide an insight into postoperative rehabilitation.

Whether Anterolateral Single Rod Can Maintain the Surgical Outcomes Following Oblique Lumbar Interbody Fusion for Double-Segment Disc Disease.

OBJECTIVE: To evaluate the outcomes of oblique lumbar interbody fusion (OLIF) combined with anterolateral single-rod screw fixation (AF) in treating two-segment lumbar degenerative disc disease (LDDD) and to determine whether AF can maintain the surgical results. METHODS: A retrospective analysis was performed on patients who underwent OLIF combined with AF (OLIF-AF) for LDDD at the L3-5 levels between October 2017 and May 2018. A total of 84 patients, including 44 males and 40 females, with a mean age of 62.8 ± 6.8 years, who completed the 12-month follow-up were eventually enrolled. Clinical outcomes, including the Oswestry Disability Index (ODI), visual analog scale (VAS) score for the low back and leg, and radiographic parameters, including the cross-sectional area (CSA) of the spinal canal, disc height (DH), foraminal height (FH), degree of upper vertebral slippage (DUVS), segmental lumbar lordosis (SL), fusion rate, and lumbar lordosis (LL), were recorded before surgery and 1 and 12 months after surgery. Surgical-related complications, including cage subsidence (CS), were also evaluated. The local radiographic parameters were compared between L3-4 and L4-5. The clinical results and all radiographic parameters were compared between patients with and without CS. RESULTS: Significant improvements were observed in radiographic parameters 1 day postoperatively (p < 0.05). Local radiological parameters in L4-5 had a significant decrease at 12 months postoperatively (p < 0.05), while they were well-maintained at L3-4 throughout the follow-up period (p > 0.05). CS was observed in 26 segments (15.5%). Endplate injury was observed in four segments (2.4%). There was no significant difference in the fusion rate between the segments with and without CS (p = 0.355). The clinical results improved significantly after surgery (p < 0.05), and no significant difference was observed between the groups with and without CS (p > 0.05). CONCLUSIONS: Anterolateral fixation combined with OLIF provides sufficient stability to sustain most radiological improvements in treating double-segment LDDD. Subsidence was the most common complication, which was prone to occur in L4-5 compared to L3-4, but did not impede the fusion process or diminish the surgical results.

[Research progress of spontaneous facet fusion after lumbar spine surgery].

Objective: To summarize the research progress on spontaneous facet fusion (SFF) after lumbar spine surgery, and provide reference for further research on SFF. Methods: The definition, development, clinical significance, and related influence factors of SFF were throughout reviewed by referring to relevant domestic and foreign literature in recent years. Results: SFF is a phenomenon of joint space disappearance and fusion of upper and lower articular processes, which starts in a ring shape from the outermost edges to the central regions. Currently reported SFF occurred after posterior lumbar pedicle screw fixation. SFF may increase the stability of surgical segments and relieve clinical symptoms of patients. SFF is closely related to the method of lumbar internal fixation, facet osteoarthritis, interbody fusion, age, body mass index, type B fracture (according to AO classification), and the operative segment. Conclusion: Most reported SFF occur after posterior lumbar pedicle screw fixation, which can increase lumbar stability, but the mechanism and influencing factors remain to be further clarified.

Low Hounsfield units on computed tomography are associated with cage subsidence following oblique lumbar interbody fusion (OLIF).

BACKGROUND CONTEXT: Cage subsidence is one of the most common complications following lumbar interbody fusion surgery. Low bone mineral density (BMD) is an important risk factor that contributes to cage subsidence. Hounsfield units (HU) obtained from clinical computed tomography (CT) scans provided a reliable method for determining regional BMD. The association between HU and cage subsidence following oblique lumbar interbody fusion (OLIF) remains unclear. PURPOSE: The objective of this study is to evaluate the association between vertebral HU value and cage subsidence following OLIF. STUDY DESIGN/SETTING: A retrospective study. PATIENT SAMPLE: Adults with degenerative spinal conditions underwent single-level OLIF at our institution from October 2017 and August 2020 OUTCOME MEASURES: Cage subsidence, disc height, vertebral body global HU value, upper and lower instrumented vertebrae HU value, endplate HU value, fusion rate. METHODS: This retrospective study was conducted on patients who underwent single-level OLIF at one institution between October 2017 and August 2020. Cage subsidence was measured using the CT scan postoperatively based on the cage protrusion through the vertebral endplates. The HU values were measured from preoperative CT according to previously reported methods. RESULTS: A total of 70 patients with a mean follow-up of 15.4 months were included in the analysis. The subsidence rate was 25.7% (n=18/70). The average cage subsidence was 2.2 mm, with a range of 0-7.7 mm. No significant difference was found in age, sex, or body mass index (BMI) between the two groups. The mean global HU value of the lumbar vertebral body (L1-5) was 142.7±30.1 in nonsubsidence and 103.7±11.5 in subsidence (p=.004). The upper instrumented vertebrae (UIV) HU value was 141.4±29.7 in the nonsubsidence and 101.1±10.2 in subsidence, (p=.005). The lower instrumented vertebrae (LIV) HU value was 147.4±34.9 in nonsubsidence and 108.1±13.7 in subsidence, (p<.001). The AUC of the UIV HU value was 0.917 (95% CI: 0.853-0.981), and the most appropriate threshold of the HU value was 115 (sensitivity: 84.6%, specificity: 100%). The AUC of the LIV HU value was 0.893 (95%CI: 0.819-0.966), and the most appropriate threshold of the HU value was 125 (sensitivity: 76.9%, specificity: 100%). The mean upper endplate HU value was 235.4±50.9, and the mean lower endplate HU value was 193.4±40.3. No significant difference (upper endplate p=.314, lower endplate p=.189) was observed between the two groups. CONSLUSIONS: Lower preoperative vertebral body HU values were associated with cage subsidence after single-level OLIF. However, the endplate HU values were not associated with cage subsidence. Preoperative HU measurement is useful in the prediction of the cage subsidence.

Comparing the medium-term outcomes of lumbar interbody fusion via transforaminal and oblique approach in treating lumbar degenerative disc diseases.

BACKGROUND CONTEXT: Oblique lumbar interbody fusion (OLIF) has been proven to be effective in treating lumbar degenerative disorders (LDDs) via indirect decompression. However, its superiority over transforaminal lumbar interbody fusion (TLIF) remains questionable, especially in terms of medium-term follow-up. PURPOSE: To compare the medium-term clinical and radiological outcomes of TLIF and OLIF in treating patients with LDDs. STUDY DESIGN: Retrospective comparative study. PATIENT SAMPLE: Fifty-two patients treated by TLIF and forty-six patients treated by OLIF. OUTCOME MEASURES: Clinical records including the visual analog scale (VAS) score of the lower back and leg and the Oswestry Disability Index (ODI). Radiological records including disk height (DH), lumbar lordosis (LL), segmental lordosis (SL), the cross-sectional area (CSA) of the spinal canal, and fusion rate. Surgical-related information and complications were also recorded. METHODS: A retrospective review was performed on patients who were surgically managed for LDDs at L4-5 between 2015 and 2017 and completed at least 4 years of follow-up. A total of 98 patients were analyzed, with 46 patients treated by OLIF combined with anterolateral single screw-rod fixation (OLIF-AF group), and 52 patients treated by TLIF (TLIF group). Parameters including postoperative outcomes and perioperative complications were compared with evaluate the efficacy of the two approaches. RESULTS: There was significantly less bleeding, surgical duration, and hospitalization in the OLIF-AF group than in the TLIF group. Significant improvements in the clinical score were achieved in both groups. However, the VAS score of the lower back was significantly higher in the TLIF group than in the OLIF-AF group throughout the whole follow-up period. Significantly higher expansion of the CSA was found in the TLIF group than in the OLIF-AF group. However, the improvements in DH, LL, and SL were significantly lower in the TLIF group. The fusion rate was significantly higher in the OLIF-AF group than in the TLIF group within 6 months postoperatively, and there was no significant difference between the two groups at the final record. No significant difference was found in the rate of overall complications between the two groups (25.0% vs. 23.9%, p=.545). The intraoperative complication rate in the TLIF group (13.5%) was slightly higher than that in the OLIF-AF group (6.5%) (p=.257). There was no significant difference in the incidence of adjacent segment disorder (ASD) between the two groups (7.7% vs. 10.9%, p=.422). Cage subsidence was slightly lower in the TLIF group (5.8%) than in the OLIF-AF group (13.0%) (p=.298). CONCLUSIONS: Both the TLIF and OLIF-AF approaches demonstrated good medium-term outcomes in treating LDDs. Compared with TLIF, OLIF-AF showed advantages in postoperative recovery, improvement of intervertebral space and lumbar sagittal balance, and early intervertebral fusion but was associated with inferior spinal canal decompression efficacy. The two approaches shared comparable overall complication rates. However, OLIF-AF tended to have fewer intraoperative complications, and a higher incidence of subsidence.

[Advances in research on Cage subsidence following lumbar interbody fusion].

OBJECTIVE: To summarize the advances in research on Cage subsidence following lumbar interbody fusion, and provide reference for its prevention. METHODS: The definition, development, clinical significance, and related risk factors of Cage subsidence following lumbar interbody fusion were throughout reviewed by referring to relevant domestic and doreign literature in recent years. RESULTS: At present, there is no consensus on the definition of Cage subsidence, and mostly accepted as the disk height reduction greater than 2 mm. Cage subsidence mainly occurs in the early postoperative stage, which weakens the radiological surgical outcome, and may further damage the effectiveness or even lead to surgical failure. Cage subsidence is closely related to the Cage size and its placement location, intraoperative endplate preparation, morphological matching of disk space to Cage, bone mineral density, body mass index, and so on. CONCLUSION: The appropriate size and shape of the Cage usage, the posterolateral Cage placed, the gentle endplate operation to prevent injury, the active perioperative anti-osteoporosis treatment, and the education of patients to control body weight may help to prevent Cage subsidence and ensure good surgical results.

Simultaneous quantification of cefuroxime and clindamycin in human lumbar anulus fibrosus, nucleus pulposus and serum via UPLC-MS/MS.

BACKGROUND: This study aimed to develop a sensitive, accurate method for simultaneously quantifying cefuroxime and clindamycin in human serum, lumbar anulus fibrosus and nucleus pulposus. METHODS: Cefuroxime and clindamycin were quantified using ultra high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple-reaction-monitoring mode on a triple-quadrupole AB Qtrap 5500 system in positive ion mode. Internal standards were D3-cefuroxime and D3,13C-clindamycin. Samples were pretreated by precipitating total protein. RESULTS: The method showed high sensitivity and good linearity over broad calibration ranges from 100 to 100 000 ng/mL for cefuroxime and 10 to 10 000 ng/mL for clindamycin in serum, and from 10 to 10 000 ng/mL for cefuroxime and 1 to 1 000 ng/mL for clindamycin in lumbar nucleus pulposus. In all sample types, correlation coefficients were greater than 0.99, intra- and inter-day precision (relative standard deviation) was less than 15%, and accuracy (relative error) was within 14% for both analytes. This method was effective at quantifying penetration of cefuroxime and clindamycin in patients undergoing oblique lumbar interbody fusion surgery. CONCLUSIONS: A very sensitive, specific method for simultaneous detection of cefuroxime and clindamycin has been developed for human lumbar anulus fibrosus, nucleus pulposus and serum samples.

[Research progress of ureteral injury in oblique lumbar interbody fusion].

OBJECTIVE: To summarize the research progress of ureteral injury in oblique lumbar interbody fusion (OLIF). METHODS: The literature about incidence, clinical manifestations, diagnosis, and treatment of ureteral injury complications in OLIF was reviewed. RESULTS: OLIF surgery poses a risk of ureteral injury because its surgical approach is anatomically adjacent to the left ureter. Ureteral injuries in OLIF are often insidious and have no specific clinical manifestations. CT urography is a common diagnostic method. The treatment of ureteral injury depends on a variety of factors such as the time of diagnosis, the location and degree of injury, and the treatment methods range from endoscopic treatment to replacement reconstruction. CONCLUSION: Surgeons should pay attention not to damage the ureter and find the abnormality in time during OLIF. High vigilance of abnormalities is conducive to the early diagnosis of ureteral injury. Furthermore, it is important to be familiar with ureter anatomy and gentle operation to prevent ureteral injury.

Minimally Invasive Oblique Lateral Lumbar Interbody Fusion Combined with Anterolateral Screw Fixation for Lumbar Degenerative Disc Disease.

OBJECTIVE: The purposes of the present study were to introduce an indirect decompression using oblique lateral lumbar interbody fusion combined with anterolateral screw fixation (OLIF-AF) for the treatment of lumbar degenerative disc disease and examine the clinical efficacy and radiographic outcomes. METHODS: A total of 65 patients had undergone single-level OLIF-AF at L2-L5 from December 2017 to August 2018. The cross-sectional area of the thecal sac was evaluated using magnetic resonance imaging. The disk height, foraminal height (FH), and degree of upper vertebral slippage were evaluated using computed tomography. The visual analog scale score and Oswestry disability index were recorded pre- and postoperatively. RESULTS: The visual analog scale scores and Oswestry disability index had significantly improved after surgery (P < 0.001). At 3 days postoperatively, the cross-sectional area had improved from 93.2 ± 14.4 mm2 to 124.2 ± 7.5 mm2 (P < 0.001), the disk height had increased from 9.9 ± 1.7 mm to 12.7 ± 1.0 mm (P < 0.001), the left FH had increased from 16.6 ± 2.0 mm to 19.6 ± 2.0 mm (P < 0.001). In contrast, the right FH had increased from 16.7 ± 2.1 mm to 19.9 ± 2.0 mm (P < 0.001), and the degree of upper vertebral slippage had decreased from 14.2% ± 3.1% to 4.6% ± 2.8% (P < 0.001), respectively. At the 12-month follow-up examination, these parameters showed no statistically significant differences compared with the values at 3 days postoperatively (P > 0.05). Adverse events were observed in 15 patients (23.1%) patients and included pain at the iliac bone donor site in 1 (1.5%), left thigh pain/numbness in 2 (3.1%), quadriceps weakness in 2 (3.1%), psoas weakness in 3 (4.6%), intraoperative endplate injury in 2 (3.1%) and cage subsidence in 5 (7.7%). CONCLUSIONS: Our results have shown that OLIF-AF surgery is a relatively safe and effective surgical option for LDDD at L2-L5. Cage subsidence was the most common operative complication.