Calcified Disc Research Articles

ADVANCING PRECISION

Augmented reality (AR) technology is revolutionizing spine surgery, offering unprecedented intraoperative image guidance and enhancing patient safety, particularly in complex procedures. This presentation explores the expanding applications of AR in spinal surgery, highlighting recent technological advances that have transformed surgical practices. In addition to improving surgical precision and accuracy, AR provides real-time visualization of critical anatomical structures, aiding in navigation and decision-making during intricate spinal procedures. This presentation will delve into the benefits that AR brings compared to classical techniques, including enhanced visualization, improved spatial awareness, and reduced radiation exposure for both patients and surgical teams. By overlaying virtual information onto the surgeon’s view of the patient, AR facilitates a more intuitive understanding of complex spinal anatomy and pathology, leading to optimized surgical outcomes. Furthermore, this session will cover the diverse applications of AR in a range of spinal conditions operated in Royal Hallamshire Hospital, Sheffield, UK - including spinal tumors, calcified disc herniation, spinal CSF-venous fistula etc. By showcasing the benefits of AR technology across various pathologies, this presentation aims to underscore its transformative potential in advancing spinal surgical care.

Dorsolateral Transdural Surgical Management of Spontaneous Intracranial Hypotension From Ventral Dural Cerebrospinal Fluid Leaks: Case Series and Technical Report

BACKGROUND and OBJECTIVES: Spontaneous intracranial hypotension is an uncommon but debilitating condition that commonly involves positional headaches and vertigo. One cause is cerebrospinal fluid (CSF) leakage from ventral dural defects from calcified spinal discs. Patients can undergo epidural blood or fibrin glue patches as treatment; however, in cases where the leak does not resolve, surgical repair of the dural tear may be warranted. We aim to describe a case series and technical notes for these patients. METHODS: Patients with spontaneous intracranial hypotension because of myelography-confirmed ventral dural defect from calcified thoracic disc, who were treated surgically between June 2020 and March 2024, were included in the study cohort. Demographic information, clinical course, and postoperative outcomes were collected. The surgical technique was also described based on an illustrative case. RESULTS: Twelve consecutive patients underwent surgery between June 2020 and March 2024 with postoperative records. The median age at the time of surgery was 41.5 years (range: 28-58 years). Male patients comprised 50% of the cohort. Dural defects were spread throughout the thoracic spine in the cohort. While all patients reported positional headaches, other symptoms included vertigo, pulsatile tinnitus, and neck pain. Median length of follow-up time was 6.5 weeks. There were no surgical complications or permanent neurologic deficits. All patients had radiologic cure of their leaks with absence of extradural CSF on postoperative MR imaging. Ten patients (83.3%) had complete resolution of spontaneous intracranial hypotension-related symptoms. Two patients did suffer from rebound headaches postoperatively. CONCLUSION: The dorsolateral transdural surgical approach is a safe and effective method to repair type 1 CSF leaks caused by ventral dural defects. Our case series of 12 patients did not involve any surgical or immediate postoperative complications, and all patients had radiologic resolution of their leaks with relief of positional headaches. Two patients experienced continued headaches after treatment.

Resection of Calcified and Giant Thoracic Disc Herniation Through Bilateral Postero-Lateral Approach and 360° Cord Release: A Technical Note

Background/Objectives: Surgical treatment of thoracic disc herniation (TDH) is risky and technically demanding due to its proximity to the spinal cord and the high possibility of the TDH being calcified (up to 40%), making the resection even more complex. Calcified TDH may be resected from an anterior via thoracotomy/thoracoscopy, lateral extra-cavitary, or a postero-lateral approach. Here, we present our experience in managing such pathology with an original technique Methods: This original technique, used successfully in more than 40 patients, is introduced, with a precise description of the surgical anatomy and the surgical steps to take. Indications for surgical management and neurological outcomes are also analyzed. This surgical approach consisted of transverso-pediculectomy, most often bilaterally, partial vertebral body drilling, 360° release of the cord, and short fixation. Results: A total of 44 patients were collected, with a mean age of 52.4 ± 11.7 years. Seven patients (15.9%) had complete calcifications, and thirty-one had partial calcifications (70.5%), while the remaining six did not have signs of calcifications. There were only 4 intraoperative complications (2 dural tears and 2 loss of evoked potentials). The TDH could be resected in total for 39 patients (88.6%) and partially, according to the “floating” technique, in 5 patients (11.4%). In the postoperative follow-up, all of the patients except two (presenting with sensory aggravation) reported an improvement in neurological conditions leading to an overall risk of neurological aggravation of 4.5%. Conclusions: The bilateral postero-lateral approach provides a large decompression of the cord (360°) and gives safe access to the TDH, even calcified, permitting high rates of total resection. It also prevents any prejudicial pressure on the spinal cord, reducing the risk of severe postoperative deficits and permitting optimal instrumentation (pedicle screw-based) of the spinal segment. The surgical sequence to resect the bony structures around the spinal cord is of great importance.

Compare three deep learning-based artificial intelligence models for classification of calcified lumbar disc herniation: a multicenter diagnostic study

ObjectiveTo develop and validate an artificial intelligence diagnostic model for identifying calcified lumbar disc herniation based on lateral lumbar magnetic resonance imaging(MRI).MethodsDuring the period from January 2019 to March 2024, patients meeting the inclusion criteria were collected. All patients had undergone both lumbar spine MRI and computed tomography(CT) examinations, with regions of interest (ROI) clearly marked on the lumbar sagittal MRI images. The participants were then divided into separate sets for training, testing, and external validation. Ultimately, we developed a deep learning model using the ResNet-34 algorithm model and evaluated its diagnostic efficacy.ResultsA total of 1,224 eligible patients were included in this study, consisting of 610 males and 614 females, with an average age of 53.34 ± 10.61 years. Notably, the test datasets displayed an impressive classification accuracy rate of 91.67%, whereas the external validation datasets achieved a classification accuracy rate of 88.76%. Among the test datasets, the ResNet34 model outperformed other models, yielding the highest area under the curve (AUC) of 0.96 (95% CI: 0.93, 0.99). Additionally, the ResNet34 model also exhibited superior performance in the external validation datasets, exhibiting an AUC of 0.88 (95% CI: 0.80, 0.93).ConclusionIn this study, we established a deep learning model with excellent performance in identifying calcified intervertebral discs, thereby offering a valuable and efficient diagnostic tool for clinical surgeons.

High-Definition 4K-3D Exoscope in Spine Surgery: A Single-Center Experience and Review of the Literature.

Background and Objectives: Binocular optical microscopy (OM) paved the way for a new era in brain and spine neurosurgery fields with the introduction of microsurgery. Despite its enormous contribution to modern neurosurgery, OM presents some intrinsic limitations that surgeons need to face during procedures such as prolonged non-ergonomic positions and decreased vision quality to the assistant eyepiece. To overcome these limitations, in recent years, new operative tools have been introduced, such as exoscopes. Here, we present our experience with exoscopes in spine surgery. Materials and Methods: In the period between January 2022 and December 2023, we gradually implemented the use of a high-definition 4K-3D exoscope (ORBEYETM, Olympus, Japan) in patients undergoing spinal surgery. Results: A total of 243 patients underwent spine surgery with exoscope magnification (47 intradural tumors, 99 lumbar degenerative cases, 79 cervical degenerative cases, 5 dorsal calcified disk herniations, 4 dural arteriovenous fistulas (dAVFs), and 9 others). We compared this cohort with a similar cohort of patients operated in the same period using OM based on different endpoints: operating time, complication rate, and infection rate. We did not find any statistically significant difference in any of the endpoints between these two groups. Conclusions: In our experience, the exoscope provides a better resolution of spinal anatomy and higher quality real-time images of the surgery for the entire OR team and improves the ergonomic posture of both surgeons, without lengthening the operating time and without increasing the rate of adverse events. Prospective studies with a larger cohort of patients are needed to further validate these findings.

Dysregulated lipid metabolism and intervertebral disc degeneration: the important role of ox-LDL/LOX-1 in endplate chondrocyte senescence and calcification

BackgroundLipid metabolism disorders are associated with degeneration of multiple tissues and organs, but the mechanism of crosstalk between lipid metabolism disorder and intervertebral disc degeneration (IDD) has not been fully elucidated. In this study we aim to investigate the regulatory mechanism of abnormal signal of lipid metabolism disorder on intervertebral disc endplate chondrocyte (EPC) senescence and calcification. MethodsHuman intervertebral disc cartilage endplate tissue, cell model and rat hyperlipemia model were performed in this study. Histology and immunohistochemistry were used to human EPC tissue detection. TMT-labelled quantitative proteomics was used to detect differential proteins, and MRI, micro-CT, safranin green staining and immunofluorescence were performed to observe the morphology and degeneration of rat tail intervertebral discs. Flow cytometry, senescence-associated β-galactosidase staining, alizarin red staining, alkaline phosphatase staining, DCFH-DA fluorescent probe, and western blot were performed to detect the expression of EPC cell senescence, senescence-associated secretory phenotype, calcification-related proteins and the activation of cell senescence-related signaling pathways. ResultsOur study found that the highly expressed oxidized low-density lipoprotein (ox-LDL) and Lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) in human degenerative EPC was associated with hyperlipidemia (HLP). TMT-labelled quantitative proteomics revealed enriched pathways such as cell cycle regulation, endochondral bone morphogenesis and inflammation. The rat model revealed that HLP could induce ox-LDL, LOX-1, senescence and calcification markers high expression in EPC. Moreover, we demonstrated that ox-LDL-induced EPCs senescence and calcification were dependent on the LOX-1 receptor, and the ROS/P38-MAPK/NF-κB signaling pathway was implicated in the regulation of senescence induced by ox-LDL/LOX-1 in cell model.ConclusionsSo our study revealed that ox-LDL/LOX-1-induced EPCs senescence and calcification through ROS/P38-MAPK/NF-κB signaling pathway, providing information on understanding the link between lipid metabolism disorders and IDD.

Rotational Latissimus Dorsi Flap for Lateral Repair of Thoracic Cerebrospinal Fluid-Pleural Fistula: Case Report.

Giant calcified thoracic discs are challenging surgical pathologies that tend to be more centrally located and calcified. This complicates the removal process and potentiates the formation of dural defects, resulting in persistent cerebrospinal fluid (CSF) leaks and the formation of pleural fistulas. The typical intervention for this is CSF diversion through external ventricular drain or lumbar drain placement, followed by direct repair. However, if all these measures fail, subsequent salvage techniques have not been described previously. A 45-year-old man with past medical history of obesity (body mass index: 58), hypertension, and type 2 diabetes mellitus presented to the emergency department with thoracic myelopathy symptoms. MR demonstrated a giant calcified thoracic discs at T7-T8 with severe spinal cord compression. Intraoperatively, the disc was found fused to the dura and removal caused a large ventrolateral dural dehiscence. CSF diversion and direct repair were attempted unsuccessfully, so a salvage procedure with a rotational pedicled latissimus dorsi flap was performed. The patient's latissimus dorsi was exposed and resected from attachments, maintaining thoracodorsal blood supply, while removing thoracodorsal innervation. The flap was then rotated into the previous corpectomy site. The dural defect was repaired with a sealant patch, overlayed with a parietal pleural flap and the latissimus dorsi flap. By the patient's last follow-up, he had full functional independence at home. We present a surgical case highlighting the challenges of managing postoperative CSF-pleural fistula occurring after giant calcified thoracic disc removal and the successful use of a novel rotational latissimus dorsi flap to definitively repair the fistula after unsuccessful primary interventions.

Oral citrate supplementation mitigates age-associated pathological intervertebral disc calcification in LG/J mice.

Despite the high prevalence of age-dependent intervertebral disc calcification, there is a glaring lack of treatment options for this debilitating pathology. Here, we investigate the efficacy of long-term oral K3Citrate supplementation in ameliorating disc calcification in LG/J mice, a model of spontaneous age-associated disc calcification. K3Citrate successfully reduced the incidence of disc calcification in LG/J mice without deleterious effects on vertebral bone structure, plasma chemistry, and locomotion. Notably, a positive effect on grip strength was evident in treated mice. Spectroscopic investigation of the persisting calcified nodules indicated K3Citrate did not alter the mineral composition and revealed that reactivation of an endochondral differentiation program in endplates may drive LG/J disc calcification. Importantly, K3Citrate reduced calcification incidence without altering the pathological endplate chondrocyte hypertrophy, suggesting mitigation of disc calcification primarily occurred through Ca2+ chelation, a conclusion supported by chondrogenic differentiation and Seahorse metabolic assays. Overall, this study underscores the therapeutic potential of K3Citrate as a systemic intervention strategy for disc calcification.

Mechanical Basis of Lumbar Intervertebral Disk Degeneration

Abstract The etiology of degenerative disk disease (DDD) is multifactorial. Among the various factors, mechanical processes contributing to endplate or discal injuries have been discussed as the initiating events in the degenerative cascade. DDD encompasses the multitudinous changes undergone by the different structures of the spinal segment, namely intervertebral disk (IVD), facet joints, vertebral end plate (VEP), adjoining marrow (Modic changes), and vertebral body. It has been etiologically linked to a complex interplay of diverse mechanisms. Mechanically, two different mechanisms have been proposed for intervertebral disk degeneration (IVDD): endplate-driven, especially in upper lumbar levels, and annulus-driven degeneration. VEP is the weakest link of the lumbar spine, and fatigue damage can be inflicted upon them under physiological loads, leading to the initiation of DDD. Disk calcification has been put forth as another initiator of inflammation, stiffening, and abnormal stresses across the IVD. The initial mechanical disruption leads to secondary IVDD through unfavorable loading of the nucleus pulposus and annulus fibrosis. The final degenerative cascade is then propagated through a combination of biological, inflammatory, autoimmune, or metabolic pathways (impaired transport of metabolites or nutrients). Abnormal spinopelvic alignment, especially pelvic incidence, also significantly impacts the degenerative process. Hence, the etiology of DDD is multifactorial. Mechanical pathways, including VEP injuries, increased disk stiffness, and abnormal spinopelvic alignment, play a significant role in the initiation of IVDD.

Prognostic factors for residual symptoms following percutaneous endoscopic lumbar discectomy.

To explore the risk factors for residual symptoms following percutaneous endoscopic lumbar discectomy (PELD). A retrospective case-controlled study. From January 2015 to December 2020, consecutive patients who underwent PELD for lumbar disc herniation (LDH) in our department were retrospectively studied. All the patients were followed-up at least two years. Residual symptoms were analyzed for association with baseline data, clinical feature, physical examination, and radiographic characteristics, which were used to detected the risk factors. A total of 339 patients were included in this study, with a mean follow-up of 28.7 ± 3.6 months. Of the enrolled patients, 90 (26.5%) patients experienced residual low back pain (LBP), and 76 (22.4%) patients experienced leg numbness (LN). Multivariate logistic regression analysis revealed that intervertebral disc calcification on CT scans (odd ratio, 0.480; 95% confidence interval: 0.247 ~ 0.932; P < 0.05) was independent risk factor for postoperative residual LBP with odd ratio and longer symptom duration was risk factor for postoperative residual LN (odd ratio, 2.231; 95% confidence interval:1.066 ~ 4.671; P < 0.05). Residual symptoms following transforaminal endoscopic surgery are quite prevalent. Intervertebral disc calcification is a protective factor for residual low back pain, and a longer symptom duration is a risk factor for residual leg numbness.

Surgical Treatment of Calcified Thoracic Herniated Disc Disease via the Transthoracic Approach with the Use of Intraoperative Computed Tomography (iCT) and Microscope-Based Augmented Reality (AR).

Background and Objectives: The aim of this study is to present our experience in the surgical treatment of calcified thoracic herniated disc disease via a transthoracic approach in the lateral position with the use of intraoperative computed tomography (iCT) and augmented reality (AR). Materials and Methods: All patients who underwent surgery for calcified thoracic herniated disc via a transthoracic transpleural approach at our Department using iCT and microscope-based AR were included in the study. Results: Six consecutive patients (five female, median age 53.2 ± 6.4 years) with calcified herniated thoracic discs (two patients Th 10-11 level, two patients Th 7-8, one patient Th 9-10, one patient Th 11-12) were included in this case series. Indication for surgery included evidence of a calcified thoracic disc on magnet resonance imaging (MRI) and CT with spinal canal stenosis of >50% of diameter, intractable pain, and neurological deficits, as well as MRI-signs of myelopathy. Five patients had paraparesis and ataxia, and one patient had no deficit. All surgeries were performed in the lateral position via a transthoracic transpleural approach (Five from left side). CT for automatic registration was performed following the placement of the reference array, with a high registration accuracy. Microscope-based AR was used, with segmented structures of interest such as vertebral bodies, disc space, herniated disc, and dural sac. Mean operative time was 277.5 ± 156 min. The use of AR improved orientation in the operative field for identification, and tailored the resection of the herniated disc and the identification of the course of dural sac. A control-iCT scan confirmed the complete resection in five patients and incomplete resection of the herniated disc in one patient. In one patient, complications occurred, such as postoperative hematoma, and wound healing deficit occurred. Mean follow-up was 22.9 ± 16.5 months. Five patients improved following surgery, and one patient who had no deficits remained unchanged. Conclusions: Optimal surgical therapy in patients with calcified thoracic disc disease with compression of dural sac and myelopathy was resectioned via a transthoracic transpleural approach. The use of iCT-based registration and microscope-based AR significantly improved orientation in the operative field and facilitated safe resection of these lesions.

Vertebral Endplate Defects Induced Mechanical Alterations and Disc Calcification.

Cross sectional comparative study. The current study aims to explore the calcification potential (BMP2 expression) of intervertebral discs and its association with the presence of vertebral endplate defects visible on MRI. Forty-seven herniated lumbar disc samples obtained from patients aged 20-76 (31M/16F) undergoing surgery. Five-µm thin sections were stained with H&E in order to assign a histological degeneration score (HDS) from 0-15 on the basis of cell density (0-5), structural alterations (0-4), granular changes (0-3) and mucus degeneration (0-3). Sections were immuno-stained with anti BMP-2 antibodies to observe the calcification potential in these discs. In addition, pre-operativeT2-T1 W MRI images of the lumbar spine were analyzed for the presence and type (typical or atypical) of vertebral endplate defects, grade of disc degeneration (Pfirrmann grade I-V), presence of high intensity zones (HIZ), and Modic changes at the operated level. Vertebral endplate defects, Modic changes & HIZ were observed in 81%, 29% and 21% of patients respectively. Mean HDS & BMP-2 expression was 9 ± 2 and mean 71 ± 36spots/mm2 respectively. Discs with adjacent vertebral endplate defects showed increased cell density (P = .004), mucus degeneration (P = .002), HDS (P = .01) and BMP-2 expression (P = .01). Discs with HIZ also had increased HDS, but significance was seen with increased BMP2 expression (P = .006). HDS showed a positive correlation with BMP 2 expression (r = .30, P = .04). These findings suggest that the altered mechanical environment of discs is strongly associated with BMP-2 expression which is an important marker of intervertebral disc calcification.

Calcified Thoracic Disc - A descriptive classification with clinical and management implications.

Thoracic disc calcification is a radiological finding which may be incidental or diagnosed in patients presenting with myelopathy due to spinal cord compression. We performed a study to analyze the imaging patterns of calcified thoracic discs (CTDs). A retrospective review of the spinal and radiology database of a tertiary referral orthopedic hospital was conducted for the incidence of CTDs between 2007 and 2020. Patients' demographics and radiological findings were recorded. The relationship between disc size, morphology, spinal cord compression, and management was assessed. Fifty-one cases of CTDs were identified. The mean size of CTD was 806.2 mm3 (range: 144-2340). The most common level of disc calcification was T9-T10 (24%) in 12 patients. Thoracic disc calcifications in our series commonly involved disc "protrusion" in 67% (34 patients), followed by "mushroom" type in 31% (16 patients) and "extrusion" in 2% (1 patient). 37% (19 patients) had spinal cord compression with 12% (6 patients) undergoing surgical interventions. There was no statistically significant difference in the mean sizes of CTD between the groups with and without spinal cord compression (P = 0.566, independent sample t-test). Patients with "mushroom" type calcification were more likely to have surgical intervention (P = 0.01, Fisher's exact test). Thoracic disc calcifications, while common, can still be underdiagnosed till late myelopathic deterioration. Care of the elderly physicians, spinal surgeons, and radiologists need to be aware of them to guide diagnosis and management. Our study demonstrates that disc morphology plays a vital role in myelopathic presentation and therefore determines the need for surgical intervention instead of the absolute size of disc calcification.

Transforaminal Endoscopic Ventral Stenosis Decompression in Calcified Lumbar Disc Herniation: A Long Term Outcome in 79 Patients

BackgroundCalcified lumbar disc herniations(CLDH) causing calcified ventral stenosis CVS) pose a therapeutic challenge to the treating surgeon due to their neural adhesions, location, and hardness. MethodsThis retrospective study analyzed all the cases of CLDH/CVS managed by transforaminal endoscopic lumbar discectomy(TELD) with a minimum follow-up of 24 months. The pre-operative images were analyzed for the level, migration; and grade(Lee’s migration zones), and location(MSU classification). Detailed surgical technique and intra-operative parameters including the duration of surgery, and complications have been recorded. The clinical parameters including VAS, ODI, length of stay (LOS) in hospital, days of return to basic work, and patient satisfaction index(PSI) were analyzed. Post-operatively the images were analyzed for the adequacy of decompression. ResultsThe mean VAS for back pain and leg pain was 4.7±2.6(0-9), and 7.45±2.2(1-10) respectively. The mean pre-operative ODI was 78.2±13.2(63.2-95.6). Nineteen patients(24%) had neurological deficits pre-operatively. The mean duration of surgery was 90.5±15.8(58- 131) minutes. Post-operative MRI revealed adequate decompression in 97.5%(n=77). The mean duration of hospital stay was 1.05±0.22(1-2) days, and the post-operative back and leg pain VAS was 1.14±1.2 (0-3) (p<0.05) and 1.7±0.5 (0-6)(p<0.05). The ODI at final follow-up was 6.5±3.7(2.2-18)(p<0.05). Neurological recovery occurred in 17(89.5%) patients and they returned to basic work/jobs in 19.5±3.3(14-26) days. The mean PSI was 1.18±0.47(1-2) at a mean follow-up of 5.52±2.91(2-12.75) years. ConclusionTELD is a complete, safe, and efficacious procedure in patients with CLDH with earlier recovery considering the surgery is performed with the patient being awake.

CT imaging features of calcium pyrophosphate dihydrate crystal deposition involving spine

PurposeTo explore the computed tomography (CT) imaging features of the spine involved by calcium pyrophosphate dihydrate crystal deposition disease (CPPD-CDD) in order to improve the understanding of this disease. Materials and methodsAmong 79 patients diagnosed with CPPD-CDD in our hospital, 51 patients with spinal involvement were selected, 9 patients without CT examination were excluded, and 42 patients were finally included as research objects. The CT images of the 42 patients were retrospectively analyzed. The analysis contents mainly included the distribution of lesions and the characteristic imaging findings of intervertebral disc, posterior ligament complex, sacroiliac joint and atlantoaxial joint. ResultsIn this paper, 42 patients with 11 males and 31 females were studied. The onset age ranged from 62 to 95 years. There were 264 lesions in 42 patients with spinal involvement, including 177 lumbar vertebrae, 43 cervical vertebrae, 27 thoracic vertebrae and 17 sacroiliac joints (14 bilateral and 3 unilateral). Characteristic imaging findings include: disc calcification (129 cases), posterior ligament complex calcification (107 cases), sacroiliac articular cartilage calcification (17 cases), and ligaments around the odontoid process calcification (11 cases). ConclusionsThe characteristic images of CPPD-CDD involving the spine are calcification of intervertebral disc, posterior ligament complex, sacroiliac joint surface and ligaments around odontoid process, and the lesions are frequent and coexisting, so it should be differentiated from gout, rheumatoid arthritis, ankylosing spondylitis, ossification of ligamentum flavum, basic calcium phosphate and infectious spondylodiscitis.

Strontium ranelate retards disc degradation and improves endplate and bone micro-architecture in ovariectomized rats with lumbar fusion induced – Adjacent segment disc degeneration

ObjectivesAdjacent segment disc degeneration (ASDD) is one of the long-term sequelae of spinal fusion, which is more susceptible with osteoporosis. As an anti-osteoporosis drug, strontium ranelate (SR) has been reported to not only regulate bone metabolism but also cartilage matrix formation. However, it is not yet clear whether SR has a reversal or delaying effect on fusion-induced ASDD in a model of osteoporosis. Materials and methodsFifth three-month-old female Sprague-Dawley rats that underwent L4-L5 posterolateral lumbar fusion (PLF) with spinous-process wire fixation 4 weeks after bilateral ovariectomy (OVX) surgery. Animals were administered vehicle (V) or SR (900 mg/kg/d) orally for 12 weeks post-PLF as follows: Sham+V, OVX + V, PLF + V, OVX + PLF + V, and OVX + PLF + SR. Manual palpation and X-ray were used to evaluate the state of lumbar fusion. Adjacent-segment disc was assessed by histological (VG staining and Scoring), histomorphometry (Disc Height, MVD, Calcification rate and Vascular Bud rate), immunohistochemical (Col-II, Aggrecan, MMP-13, ADAMTS-4 and Caspase-3), and mRNA analysis (ColI, Col-II, Aggrecan, MMP-13 and ADAMTS-4). Adjacent L6 vertebrae microstructures were evaluated by microcomputed tomography. ResultsManual palpation and radiographs showed clear evidence of the fused segment's immobility. After 12 weeks of PLF surgery, a fusion-induced ASDD model was established. Low bone mass caused by ovariectomy can significantly exacerbate ASDD progression. SR exerted a protective effect on adjacent segment intervertebral disc with the underlying mechanism possibly being associated with preserving bone mass to prevent spinal instability, maintaining the functional integrity of endplate vascular microstructure, and regulating matrix metabolism in the nucleus pulposus and annulus fibrosus. DiscussionAnti-osteoporosis medication SR treatments not only maintain bone mass and prevent fractures, but early intervention could also potentially delay degenerative conditions linked to osteoporosis. Taken together, our results suggested that SR might be a promising approach for the intervention of fusion-induced ASDD with osteoporosis.

A rare case of intervertebral disc calcification combined with ossification of the posterior longitudinal ligament in a child: a case report and literature review

BackgroundIntervertebral disc calcification (IDC) combined with calcification in children has been sporadically reported, while ossification of the posterior longitudinal ligament (OPLL) in the cervical spine in pediatric patients is exceedingly rare. The aim of this study is to investigate the potential prognosis and outcomes associated with this condition.Case presentationWe present an unusual case involving a 10-year-old Chinese child diagnosed with calcified cervical disc herniation and ossification of the posterior longitudinal ligament. Conservative treatment measures were implemented, and at the 1-month and 6-month follow-up, the patient's pain exhibited significant improvement. Subsequent cervical MRI and CT scans revealed the complete disappearance of OPLL and substantial absorption of the calcified disc. During the three-month follow-up, CT demonstrated slight residual disc calcification, however, the patient remained asymptomatic with no discernible limitation in cervical motion.ConclusionsWe conducted a comprehensive review of several cases presenting with the same diagnosis. It is noteworthy that IDC combined with OPLL in children constitutes a rare clinical entity. Despite imaging indications of potential spinal canal occupation, the majority of such cases demonstrate complete absorption following conservative treatment, with OPLL exhibiting a faster absorption rate than calcified discs.

Technical Nuances of the Posterior Transpedicular Thoracic Diskectomy: 2-Dimensional Operative Video.

Thoracic disk herniations are relatively rare when compared with cervical and lumbar disk pathology accounting for less than 3% of spinal disk herniations.1 In addition to this, a larger proportion of thoracic disk herniations are calcified making them challenging to remove because of adherence to the dura and anatomy of the thoracic spinal canal.2,3 Owing to these unique features of thoracic disk herniations, typical posterior approaches are not always feasible to provide adequate decompression of the thecal sac.4 In this video, we present a 64-year-old male patient who presented with progressive paraplegia and a large ventral, eccentric, calcified thoracic disk herniation causing severe canal stenosis. Because of the size and location of the disk, a thoracic laminectomy with costotransversectomy and pediculectomies for resection of the disk was performed. Ventral decompression was achieved, and the patient made a full neurologic recovery. This video highlights the principles and technical nuances used during thoracic disk resection. The patient provided informed consent for surgery and video recording.

Treatment of L5-S1 Floating Calcified Lumbar Disc Herniation with Percutaneous Endoscopic Interlaminar Discectomy.

The floating calcified tissue in floating calcified lumbar disc herniation (FCLDH) is hard and often adheres to the dura mater, which can easily cause nerve root damage during surgery, making the operation challenging. We proposed the classification of FCLDH and a new technique for removing floating calcified tissue and reported the clinical efficacy and safety of this new technique in clinical practice. From January 2019 to October 2021, 24 patients (13 males and 11 females, 46.4 ± 7.72 years) with L5-S1 floating calcified lumbar disc herniation were treated with percutaneous endoscopic interlaminar discectomy (PEID). According to FCLDH classification, a total of Type Ia: nine cases, Type Ib: five cases, Type IIa: four cases, and Type IIa: six cases were included. The visual analogue scale (VAS) and Oswestry disability index (ODI) were recorded pre-operatively and 3 days postoperatively, 6 months postoperatively, and at the last follow-up. The postoperative curative effect was evaluated according to the modified MacNab criteria. Computed tomography (CT) and magnetic resonance imaging (MRI) of the lumbar spine were performed 3 days after surgery to evaluate the efficacy of the surgery. All patients successfully underwent PEID. The VAS and ODI scores at 3 days postoperatively, 6 months postoperatively, and at the last follow-up were significantly improved and statistically significant compared to those of the preoperative period (p < 0.05). All the patients were followed up for 12-24 months (mean, 16.6 ± 4.6 months). At the last follow-up, according to the modified MacNab criteria, 15 cases were excellent, eight were good, and one was fair. The combined excellent and good rate was 95.83% (23/24). Postoperative review revealed that all floating calcified tissues were effectively removed and the nerve roots were adequately decompressed without complications such as cerebrospinal fluid leakage and lumbar spine infection. The classification of FCLDH we proposed can well guide the selection of surgical plans. PEID combined with floating calcified tissue removal technology has good efficacy in the treatment of L5-S1 FCLDH, ensuring accurate removal of calcified tissue, reducing complications and improving the quality of life of affected individuals.

A new perspective on intervertebral disc calcification-from bench to bedside.

Disc degeneration primarily contributes to chronic low back and neck pain. Consequently, there is an urgent need to understand the spectrum of disc degeneration phenotypes such as fibrosis, ectopic calcification, herniation, or mixed phenotypes. Amongst these phenotypes, disc calcification is the least studied. Ectopic calcification, by definition, is the pathological mineralization of soft tissues, widely studied in the context of conditions that afflict vasculature, skin, and cartilage. Clinically, disc calcification is associated with poor surgical outcomes and back pain refractory to conservative treatment. It is frequently seen as a consequence of disc aging and progressive degeneration but exhibits unique molecular and morphological characteristics: hypertrophic chondrocyte-like cell differentiation; TNAP, ENPP1, and ANK upregulation; cell death; altered Pi and PPi homeostasis; and local inflammation. Recent studies in mouse models have provided a better understanding of the mechanisms underlying this phenotype. It is essential to recognize that the presentation and nature of mineralization differ between AF, NP, and EP compartments. Moreover, the combination of anatomic location, genetics, and environmental stressors, such as aging or trauma, govern the predisposition to calcification. Lastly, the systemic regulation of calcium and Pi metabolism is less important than the local activity of PPi modulated by the ANK-ENPP1 axis, along with disc cell death and differentiation status. While there is limited understanding of this phenotype, understanding the molecular pathways governing local intervertebral disc calcification may lead to developing disease-modifying drugs and better clinical management of degeneration-related pathologies.