OBJECTIVES: In the early stage of central cervical disc herniation, clinical symptoms may be mild. However, as the spinal cord becomes compressed by herniated nucleus pulposus tissue, progressive edema and degeneration may occur, resulting in more severe clinical manifestations, including limb weakness, bladder and bowel dysfunction, spastic paraplegia of the lower extremities, and even respiratory difficulty. The spinal endoscopic Key-hole technique is widely applied in treating radiculopathic cervical spondylosis and has demonstrated good clinical outcomes. This study aims to analyze and summarize the technical points and therapeutic efficacy of the far lateral Key-hole technique in the treatment of central cervical disc herniation, providing reference for clinical application. METHODS: Eight patients with central cervical disc herniation treated with the far lateral Key-hole technique were included as the experimental group. Another 8 patients who underwent single-level anterior cervical diskectomy and fusion (ACDF) during the same period were selected as the control group. Data collected included gender, age, intraoperative blood loss, incision length, and length of hospitalization. Pain severity was evaluated using the Visual Analogue Scale (VAS); cervical function was assessed using the Japanese Orthopaedic Association (JOA) score; and cervical disability was measured by the neck disability index (NDI). Radiological outcomes were assessed using disc height index (DHI), cervical Cobb angle, and operative segment Cobb angle. RESULTS: Compared with the control group, the experimental group had significantly less intraoperative blood loss, shorter incision length, and shorter hospital stay (all P<0.05), while there was no significant difference in operation time (P>0.05). Postoperative VAS and NDI scores in both groups were significantly lower than preoperative values, and JOA scores significantly improved (P<0.05). No significant differences were noted between the two groups preoperatively (P>0.05). Postoperatively, the experimental group showed significantly lower VAS and NDI scores and higher JOA scores than the control group (P<0.05). There was no statistical significance in DHI before and after surgery in the experimental group (P>0.05), while the DHI increased significantly postoperatively in the control group (P<0.05). Postoperative DHI in the experimental group was significantly lower than in the control group (P<0.05). No significant differences were observed in the cervical Cobb angle either within or between groups (all P>0.05). The operative segment Cobb angle increased significantly after surgery in the control group (P<0.05), while no other operative segment angle changes were statistically significant (all P>0.05). CONCLUSIONS The far lateral Key-hole technique offers advantages in treating central cervical disc herniation, including reduced intraoperative bleeding, smaller incision length, shorter hospitalization, and improved postoperative pain relief. Additionally, the technique does not affect cervical physiological curvature or stability in the short term, making it suitable for clinical application.
Humans ; Intervertebral Disc Displacement/surgery* ; Cervical Vertebrae/surgery* ; Male ; Female ; Middle Aged ; Adult ; Diskectomy/methods* ; Treatment Outcome ; Spinal Fusion/methods* ; Endoscopy/methods*

Lumbar disc (LD) herniation and aging are prevalent conditions that can result in substantial morbidity. This study aimed to clarify the mechanisms connecting the LD aging and herniation, particularly focusing on cellular senescence and molecular alterations in the nucleus pulposus (NP). We performed a detailed analysis of NP samples from a diverse cohort, including individuals of varying ages and those with diagnosed LD herniation. Our methodology combined histological assessments with single-nucleus RNA sequencing to identify phenotypic and molecular changes related to NP aging and herniation. We discovered that cellular senescence and a decrease in nucleus pulposus progenitor cells (NPPCs) are central to both processes. Additionally, we found an age-related increase in NFAT1 expression that promotes NPPC senescence and contributes to both aging and herniation of LD. This research offers fresh insights into LD aging and its associated pathologies, potentially guiding the development of new therapeutic strategies to target the root causes of LD herniation and aging.
Intervertebral Disc Displacement/metabolism* ; Humans ; Aging/pathology* ; Nucleus Pulposus/pathology* ; Male ; Female ; Transcriptome ; Middle Aged ; Lumbar Vertebrae/pathology* ; Adult ; Cellular Senescence ; Stem Cells/pathology* ; Aged ; Intervertebral Disc Degeneration/metabolism*

OBJECTIVES: This study aimed to evaluate the effect of disc morphology and disc-condyle angle on the treatment of anterior repositioning splint (ARS) for anterior disc displacement with reduction (ADDwR). METHODS: On the basis of the inclusion and exclusion criteria, a total of 11 patients diagnosed with ADDwR were included. The effects of changes in disc length, thickness, and morphology classifications on the clinical symptoms, disc morphology parameters, and disc-condyle angles after ARS treatment were evaluated using magnetic resonance imaging and the Helkimo index. RESULTS: After ARS treatment, the Ai and Di of all patients with ADDwR decreased, the disc length increased, and the thickness decreased. The Ai of patients with slight ADDwR and those with type 1 joint discs was reduced to 0, with the most significant decrease observed in Di. The disc length of mild ADDwR (increased to 8.65 mm±1.79 mm) and type 5 disc (increased to 10.71 mm±2.62 mm) significantly increased the most. The disc thickness of slight ADDwR decreased to 3.08 mm±0.51 mm significantly. CONCLUSIONS The therapeutic effect of ARS is correlated with the displacement degree and morphological features of the disc, providing evidence for clinical treatment decisions.
Humans ; Magnetic Resonance Imaging ; Conservative Treatment ; Temporomandibular Joint Disc/diagnostic imaging* ; Male ; Adult ; Female ; Intervertebral Disc Displacement/pathology* ; Middle Aged

Intervertebral disc degeneration (IDD) is the main cause of low back pain. Immune cells play an extremely important role in regulating the progression of IDD by interacting with nucleus pulposus (NP) cells and the extracellular matrix (ECM). Healthy NP tissue is a vascular-free and immune-privileged tissue that does not normally interact with macrophages. However, the establishment of neovascularization channels in damaged intervertebral discs has led to extensive cross-talk between NP and macrophages, with different results depending on microenvironmental stimuli. Based on this, this review reviewed the correlation between IDD and low back pain, summarized the source and function of macrophages, and discussed the possible regulatory mechanism between macrophages and discogenic pain. Finally, potential therapies targeting macrophages to delay IDD in recent years were also discussed, aiming to emphasize the important role of immunology in IDD and provide a new direction for the prevention and treatment of IDD.
Humans ; Intervertebral Disc Degeneration/complications* ; Macrophages/immunology* ; Low Back Pain/immunology* ; Nucleus Pulposus ; Animals ; Extracellular Matrix

Extracellular vesicles (EVs), defined as cell-secreted nanoscale vesicles that carry bioactive molecules, have emerged as a promising therapeutic strategy in tumor and tissue regeneration. Their potential in repairing intervertebral disc degeneration (IDD) through multidimensional regulatory mechanisms is a rapidly advancing field of research. This paper provided an overview of the mechanisms of EVs in IDD repair, thoroughly reviewed recent literature on EVs for IDD, domestically and internationally, and summarized their therapeutic mechanisms. In IDD repair, EVs could act through different mechanisms at the molecular, cellular, and tissue levels. At the molecular level, EVs could treat IDD by inhibiting inflammatory reactions, suppressing oxidative stress, and regulating the synthesis and decomposition of extracellular matrix. At the cellular level, EVs could treat IDD by inhibiting cellular pyroptosis, ferroptosis, and apoptosis and promoting cell proliferation and differentiation. At the tissue level, EVs could treat IDD by inhibiting neovascularization. EVs have a strong potential for clinical application in the treatment of IDD and deserve more profound study.
Extracellular Vesicles/physiology* ; Humans ; Intervertebral Disc Degeneration/therapy* ; Apoptosis ; Cell Proliferation ; Oxidative Stress ; Cell Differentiation ; Extracellular Matrix/metabolism* ; Animals ; Pyroptosis

The lumbar intervertebral disc exhibits a complex physiological structure with interactions between various segments, and its components are extremely complex. The material properties of different components in the lumbar intervertebral disc, especially the water content (undergoing dynamic change as influenced by age, degeneration, mechanical loading, and proteoglycan content) - critically determine its mechanical properties. When the lumbar intervertebral disc is under continuous pressure, water seeps out, and after the pressure is removed, water re-infiltrates. This dynamic fluid exchange process directly affects the mechanical properties of the lumbar intervertebral disc, while previous isotropic modeling methods have been unable to accurately reflect such solid-liquid phase behaviors. To explore the load-bearing mechanism of the lumbar intervertebral disc and establish a more realistic mechanical model of the lumbar intervertebral disc, this study developed a solid-liquid biphasic, fiber-reinforced finite element model. This model was used to simulate the four movements of the human lumbar spine in daily life, namely flexion, extension, axial rotation, and lateral bending. The fluid pressure, effective solid stress, and liquid pressure-bearing ratio of the annulus fibrosus and nucleus pulposus of different lumbar intervertebral discs were compared and analyzed under the movements. Under all the movements, the fluid pressure distribution was closer to the nucleus pulposus, while the effective solid stress distribution was more concentrated in the outer annulus fibrosus. In terms of fluid pressure, the maximum fluid pressure of the lumbar intervertebral disc during lateral bending was 1.95 MPa, significantly higher than the maximum fluid pressure under other movements. Meanwhile, the maximum effective solid stress of the lumbar intervertebral disc during flexion was 2.43 MPa, markedly higher than the maximum effective solid stress under other movements. Overall, the liquid pressure-bearing ratio under axial rotation was smaller than that under other movements. Based on the solid-liquid biphasic modeling method, this study more accurately revealed the dominant role of the liquid phase in the daily load-bearing process of the lumbar intervertebral disc and the solid-phase mechanical mechanism of the annulus fibrosus load-bearing, and more effectively predicted the solid-liquid phase co-load-bearing mechanism of the lumbar intervertebral disc in daily life.
Humans ; Finite Element Analysis ; Intervertebral Disc/physiology* ; Lumbar Vertebrae/physiology* ; Weight-Bearing/physiology* ; Biomechanical Phenomena ; Stress, Mechanical ; Computer Simulation ; Models, Biological

OBJECTIVE: To investigate the short-term effectiveness of uni-portal non-coaxial spinal endoscopic surgery (UNSES) via crossing midline approach (CMA) in the treatment of free lumbar disc herniation (FLDH). METHODS: Between March 2024 and June 2024, 16 patients with FLDH were admitted and treated with UNSES via CMA. There were 9 males and 7 females with an average age of 55.1 years (range, 47-62 years). The disease duration was 8-30 months (mean, 15.6 months). The pathological segments was L _{3, 4} in 4 cases, L _{4, 5} in 5 cases, and L ₅, S ₁ in 7 cases. The preoperative pain visual analogue scale (VAS) score was 6.9±0.9 and the Oswestry disability index (ODI) was 57.22%±4.16%. The operation time, intraoperative bleeding volume, postoperative hospital stay, and incidence of complications were recorded. The spinal pain and functional status were evaluated by VAS score and ODI, and effectiveness was evaluated according to the modified MacNab criteria. CT and MRI were used to evaluate the effect of nerve decompression. RESULTS: All 16 patients underwent operation successfully without any complications. The operation time was 63-81 minutes (mean, 71.0 minutes). The intraoperative bleeding volume was 47.3-59.0 mL (mean, 55.0 mL). The length of hospital stay after operation was 3-4 days (mean, 3.5 days). All patients were followed up 1-3 months, with 15 cases followed up for 2 months and 14 cases for 3 months. The VAS score and ODI gradually decreased over time after operation, and there were significant differences between different time points ( P<0.05). At 3 months after operation, the effectiveness was rated as excellent in 12 cases and good in 2 cases according to the modified MacNab criteria, with an excellent and good rate of 100%. CT and MRI during follow-up showed a significant increase in the diameter and cross-sectional area of the spinal canal, indicating effective decompression of the canal. CONCLUSION When using UNSES to treat FLDH, choosing CMA for nerve decompression has the advantages of wide decompression range, large operating space, and freedom of operation. It can maximize the preservation of the articular process, avoid fracture and breakage of the isthmus, clearly display the exiting and traversing nerve root, and achieve good short-term effectiveness.
Humans ; Male ; Intervertebral Disc Displacement/diagnostic imaging* ; Middle Aged ; Female ; Lumbar Vertebrae/surgery* ; Endoscopy/methods* ; Treatment Outcome ; Operative Time ; Pain Measurement ; Length of Stay

OBJECTIVE: To investigate the effectiveness of digital three-dimensional (3D) assisted unilateral biportal endoscopy (UBE) in the treatment of highly isolated lumbar disc herniation (LDH) with translaminar approach. METHODS: The clinical data of 59 patients who met the selection criteria and underwent UBE treatment due to highly isolated LDH between January 2022 and December 2023 were retrospectively analyzed. Among them, 25 cases were treated with digital 3D assisted translaminar approach (observation group) and 34 cases were treated with interlaminar approach (control group). There was no significant difference in gender, age, disease duration, surgical segment, and preoperative visual analogue scale (VAS) score and Oswestry disability index (ODI) between the two groups ( P>0.05). The operation time, intraoperative blood loss, and lateral articular surface preservation rate were recorded and compared between the two groups. VAS score and ODI were used to evaluate the improvements of pain and function before operation and at 3 and 6 months after operation. The modified MacNab criteria was used to evaluate the effectiveness at last follow-up. RESULTS: One patient in the control group had dural tear, and the other patients had no nerve injury, infection, dural tear, or other related complications. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). Patients in both groups were followed up 6-13 months, with an average of 8.3 months. The lateral articular surface preservation rate in the observation group was significantly higher than that in the control group ( P<0.05). Three patients in the observation group and 2 patients in the control group had calf muscle venous thrombosis, which was cured after anticoagulant treatment with rivaroxaban and delayed exercise time. There was no recurrence or second operation during the follow-up period. The VAS score and ODI of the two groups at 3 and 6 months after operation significantly improved when compared with those before operation ( P<0.05). There was no significant difference between the two groups at each time point after operation ( P>0.05). At last follow-up, the effectiveness was evaluated according to the modified MacNab criteria, and there was no significant difference in the evaluation grade and excellent and good rate between the two groups ( P>0.05). CONCLUTION UBE via translaminar approach is safe and effective for the treatment of highly isolated LDH, which is beneficial to protect the facet joint, maintain spinal stability, and reduce soft tissue injury. With the assistance of digital 3D technique, preoperative planning can be performed accurately.
Humans ; Intervertebral Disc Displacement/diagnostic imaging* ; Lumbar Vertebrae/diagnostic imaging* ; Male ; Retrospective Studies ; Female ; Endoscopy/methods* ; Treatment Outcome ; Middle Aged ; Adult ; Imaging, Three-Dimensional ; Operative Time ; Pain Measurement

OBJECTIVE: To evaluate early effectiveness of posterior 180-degree decompression via unilateral biportal endoscopy (UBE) in the treatment of lumbar spinal stenosis (LSS) combined with Michigan State University (MSU)-1 lumbar disc herniation (LDH). METHODS: A retrospective analysis was conducted on clinical data from 33 patients with LSS combined with MSU-1 LDH, who met selection criteria and were treated between March 2022 and January 2024. All patients underwent UBE-assisted 180-degree spinal canal decompression. The cohort comprised 17 males and 16 females, aged 37-82 years (mean, 67.1 years). Preoperative presentations included bilateral lower limbs intermittent claudication and radiating pain, with disease duration ranging from 5 to 13 months (mean, 8.5 months). Affected segments included L _{3, 4} in 4 cases, L _{4, 5} in 28 cases, and L ₅, S ₁ in 1 case. LSS was rated as Schizas grade A in 4 cases, grade B in 5 cases, grade C in 13 cases, and grade D in 11 cases. LDH was categorized as MSU-1A in 24 cases, MSU-1B in 2 cases, and MSU-1AB in 7 cases. Intraoperative parameters (operation time, blood loss) and postoperative hospitalization length were recorded. The visual analogue scale (VAS) score and Oswestry Disability Index (ODI) were used to assess the lower limb pain and functional outcomes after operation. Clinical efficacy was evaluated at last follow-up via modified MacNab criteria. Quantitative radiological assessments included dural sac cross-sectional area (DSCA) measurements and spinal stenosis grading on lumbar MRI. Morphological classification of lumbar canal stenosis was determined according to the Schizas grading, categorized into four grades. RESULTS: The operation time was 60.4-90.8 minutes (mean, 80.3 minutes) and intraoperative blood loss was 13-47 mL (mean, 29.9 mL). The postoperative hospitalization length was 3-5 days (mean, 3.8 days). All patients were followed up 12-16 months (mean, 13.8 months). The VAS score and ODI improved at immediate and 3, 6, and 12 months after operation compared to before operation, and the differences between different time points were significant ( P<0.05). At last follow-up, the clinical efficacy assessed by the modified MacNab criteria were graded as excellent in 23 cases, good in 9 cases, and poor in 1 case, with an excellent and good rate of 96.97%. Postoperative lumbar MRI revealed the significant decompression of the dural sac in 32 cases, with 1 case showing inadequate dural expansion. DSCA measurements confirmed progressive enlargement and stenosis reduction over time. The differences were significant ( P<0.05) before operation, immediately after operation, and at 6 months after operation. At 6 months after operation, Schizas grading of spinal stenosis improved to grade A in 27 cases and grade B in 6 cases. CONCLUSION Posterior 180-degree decompression via UBE is a safe and feasible strategy for treating LSS combined with MSU-1 LDH, achieving effective neural decompression while preserving intervertebral disc integrity.
Humans ; Spinal Stenosis/diagnostic imaging* ; Male ; Female ; Aged ; Lumbar Vertebrae/surgery* ; Middle Aged ; Intervertebral Disc Displacement/complications* ; Decompression, Surgical/methods* ; Retrospective Studies ; Endoscopy/methods* ; Adult ; Aged, 80 and over ; Treatment Outcome

OBJECTIVE: To summarize recent research progress in hydrogel-based growth factors for treatment of intervertebral disc degeneration (IDD). METHODS: The relevant literature on hydrogel-based growth factors for IDD treatment at home and abroad was extensively reviewed, and their advantages and therapeutic effects in repairing IDD were analyzed and summarized. RESULTS: Hydrogels exhibit high hydration, biocompatibility, and biodegradability, enabling targeted delivery and sustained release of growth factors such as growth differentiation factors and transforming growth factors. This facilitates enhanced efficacy in promoting cell proliferation, extracellular matrix synthesis, and reducing inflammatory responses. Consequently, hydrogels demonstrate broad application prospects in the repair of IDD. CONCLUSION Research on hydrogel-based growth factors for treating IDD demonstrates advantages such as avoiding disc damage caused by repeated injections and controlling growth factor release concentrations. However, drawbacks include the limited variety of loaded growth factors and the need to verify the long-term stability and biocompatibility of hydrogels. Therefore, further research is required on aspects such as the types of loaded growth factors and the long-term stability and biocompatibility of hydrogels to establish an experimental foundation for their clinical application.
Intervertebral Disc Degeneration/therapy* ; Hydrogels/chemistry* ; Humans ; Intercellular Signaling Peptides and Proteins/administration & dosage* ; Biocompatible Materials/chemistry* ; Animals ; Tissue Engineering/methods* ; Cell Proliferation/drug effects* ; Drug Delivery Systems