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Materials for the Spine: Anatomy, Problems, and Solutions
Abstract
Disc degeneration affects 12% to 35% of a given population, based on genetics, age, gender, and other environmental factors, and usually occurs in the lumbar spine due to heavier loads and more strenuous motions. Degeneration of the extracellular matrix (ECM) within reduces mechanical integrity, shock absorption, and swelling capabilities of the intervertebral disc. When severe enough, the disc can bulge and eventually herniate, leading to pressure build up on the spinal cord. This can cause immense lower back pain in individuals, leading to total medical costs exceeding $100 billion. Current treatment options include both invasive and noninvasive methods, with spinal fusion surgery and total disc replacement (TDR) being the most common invasive procedures. Although these treatments cause pain relief for the majority of patients, multiple challenges arise for each. Therefore, newer tissue engineering methods are being researched to solve the ever-growing problem. This review spans the anatomy of the spine, with an emphasis on the functions and biological aspects of the intervertebral discs, as well as the problems, associated solutions, and future research in the field.
... Intervertebral discs (IVDs) make up about 20-30% of the spine length [1]; function as shock distributers, load cushions, stress dispersers and weight carriers; and vary in size and constitution according to their anatomical locations, spinal level, the organism's age and biomechanical demands/functions [1][2][3][4]. IVDs are avascular and receive nutrition from the adjacent blood vessels through diffusion, which is a contributing cause of degeneration [1]. ...
... Intervertebral discs (IVDs) make up about 20-30% of the spine length [1]; function as shock distributers, load cushions, stress dispersers and weight carriers; and vary in size and constitution according to their anatomical locations, spinal level, the organism's age and biomechanical demands/functions [1][2][3][4]. IVDs are avascular and receive nutrition from the adjacent blood vessels through diffusion, which is a contributing cause of degeneration [1]. An annulus fibrosus (AF), composed of water, collagen (types 1 and 2), proteoglycans (PG) and extracellular matrix (ECM) proteins with two main layers, encloses the central nucleus pulposus (NP) [1,5]. ...
... Intervertebral discs (IVDs) make up about 20-30% of the spine length [1]; function as shock distributers, load cushions, stress dispersers and weight carriers; and vary in size and constitution according to their anatomical locations, spinal level, the organism's age and biomechanical demands/functions [1][2][3][4]. IVDs are avascular and receive nutrition from the adjacent blood vessels through diffusion, which is a contributing cause of degeneration [1]. An annulus fibrosus (AF), composed of water, collagen (types 1 and 2), proteoglycans (PG) and extracellular matrix (ECM) proteins with two main layers, encloses the central nucleus pulposus (NP) [1,5]. ...
Intervertebral disc (IVD) degeneration is a common cause of low back pain in diabetes mellitus type 2 (T2DM) patients. Its pathogenesis and the vitamin (vit.) K2 influence on this disease remain unclear. Lumbar motion segments of male Zucker Diabetes Fatty (ZDF) rats (non-diabetic [control] and diabetic; fed without or with vit. K2) were used. Femur lengths and vertebral epiphyseal cross-section areas were measured. IVDs were histopathologically examined. Protein synthesis and gene expression of isolated IVD fibrochondrocytes were analyzed. T2DM rats showed histopathological IVD degeneration. Femur lengths and epiphyseal areas were smaller in T2DM rats regardless of vit. K2 feeding. Fibrochondrocytes synthesized interleukin (IL)-24 and IL-10 with no major differences between groups. Alpha smooth muscle actin (αSMA) was strongly expressed, especially in cells of vit. K2-treated animals. Gene expression of aggrecan was low, and that of collagen type 2 was high in IVD cells of diabetic animals, whether treated with vit. K2 or not. Suppressor of cytokine signaling (Socs)3 and heme oxygenase (Hmox)1 gene expression was highest in the cells of diabetic animals treated with vit. K2. Vit. K2 influenced the expression of some stress-associated markers in IVD cells of diabetic rats, but not that of IL-10 and IL-24.
... The spine is constructed out of vertebrae, as well as intervertebral discs. The mobility is granted by the intervertebral discs, which will not endanger the vertebral column's supportive strength [1]. The human vertebral column consists of 33 vertebrae classified as cervical, thoracic, lumbar, sacral, and coccyx [2,3]. ...
... The spinous process protrudes perpendicular to the body. The facets are curved articular surfaces [1,7]. As the lumbar region is less mobile and has a vast muscular structure, any derangement leads to pain and hampers the activities of daily living [8]. ...
... Nerve root-associated LBP is due to the nerves getting compressed at the spinal level; the pain is sharp and burning in nature, radiating to the nerve course. Pathologic LBP is due to underlying pathology, which can 1 2 1 be a pathology of the bones, muscles, or intervertebral disc. The prolapsed intervertebral disc is a common cause of LBP [2]. ...
Background
Pain lasting more than three months is termed chronic pain. Treating chronic pain is always a challenge for the therapist. Low back pain (LBP) with a high prevalence is a point of concern. Various treatment methods are available. The two treatment methods are integrated neuromuscular inhibition technique (INIT) and Mulligan mobilization with movement (MWM). In this study, we have compared INIT with MWM.
Method
It was an interventional study carried out at Ravi Nair Physiotherapy College and Acharya Vinoba Bhave Rural Hospital. A total of 80 participants with nonspecific LBP were included in the study. The participants were randomly divided into two groups and treated for two weeks with three weekly sessions.
Statistical analysis and result
Statistical analysis was done post the completion of sampling. Paired and unpaired t-tests were used. A p-value of <0.05 was considered significant. The result was obtained after comparing the pre- and post-values of the numerical pain rating scale (NPRS), modified Oswestry disability index (MODI), and range of motion (ROM) of the lumbar joint. After two weeks of treatment, a reduction in functional disability and pain was seen in the INIT and MWM groups. ROM was increased after two weeks of treatment in both INIT and MWM groups. When compared, INIT showed better results than MWM.
Conclusion
In conclusion, we saw that the integrated neuromuscular inhibition technique might be a better technique than Mulligan mobilization with movement in terms of reducing pain and functional disability.
... IVD is a closed fibrocartilaginous structure composed of three parts: the central nucleus pulposus (NP), the outer annular fibrosus (AF), and the upper and lower cartilage endplates (CEP). Under normal circumstances, the IVD lacks a blood supply, making it difficult for exogenous inflammatory cytokines to reach the interior of the IVD [13]. Studies have shown that even in normal IVD, there are inflammatory cytokines present, such as IL-1α, IL-1β, IL-6, IL-8, and TNF-α. ...
... IDD is a lengthy and complex pathological process involving structural and functional damage to the IVD [13]. The physiological characteristics of the IVD restrict the transport of nutrients and oxygen within the disc. ...
Background
Intervertebral disc degeneration (IDD) is a leading cause of low back pain (LBP), posing a significant socioeconomic burden. Recent studies highlight the crucial role of inflammatory microenvironment in IDD progression.
Method
A keyword-based search was performed using the PubMed database for published articles.
Results and conclusions
Dysregulated expression of inflammatory cytokines disrupts intervertebral disc (IVD) homeostasis, causing atrophy, fibrosis, and phenotypic changes in nucleus pulposus cells. Modulating the inflammatory microenvironment and restoring cytokine balance hold promise for IVD repair and regeneration. This comprehensive review systematically examines the expression regulation, pathological effects, therapeutic strategies, and future challenges associated with the inflammatory microenvironment and relevant cytokines in IDD. Key inflammatory cytokines, including interleukins (IL), tumor necrosis factor-alpha (TNF-α), and chemokines, exhibit significant pathological effects in IDD. Furthermore, major therapeutic modalities such as chemical antagonists, biologics, plant extracts, and gene transcription therapies are introduced to control and ameliorate the inflammatory microenvironment. These approaches provide valuable insights for identifying potential targets in future anti-inflammatory treatments for IDD.
... Knowledge of biomechanics enables a better understanding of the role of bones and associated soft tissues in stabilizing the spine, as well as an understanding of the destabilizing effects that can occur due to the appearance of tumors, traumatic and degenerative damages [1]. In a functional sense, bone and soft tissue structures are closely connected and their mutual action achieves the stability of the spine and its mobility in all three axes [2]. ...
... In humans, who are bipedal organisms, the thoracic part of the spine has limited mobility because ribs are attached to the vertebrae at one end and to the sternum at the other end. Unlike the thoracic segment, the mobility of the lumbar spine is significantly higher and at the same time, it bears the greatest axial load [2]. It is known that bones adapt to the action of mechanical forces by changing their morphology [3], so the size of the thoracic vertebrae in humans increases from the first to the last [1], and this trend continues distally so that the last lumbar vertebra has the greatest length, height and width [4]. ...
Numerous studies are based on the use of animal models; however, in bipedal and tetrapedal organisms there are significant differences in the biomechanics of the spinal column, which can significantly impair the quality and applicability of the results obtained. The aim of this study is to obtain basic data on the morphometric parameters of guinea pig lumbar vertebrae, the analysis of which will indicate the location of the biggest mechanical load. The lumbar vertebra morphometry test was performed by means of X-ray imageing obtained from 12 guinea pigs, with equal numbers of males and females. The results of investigations show that guinea pig lumbar vertebrae have an irregular trapezoid geometry and that the measured body lengths of L4 and L5 are the largest. The height parameters determined in the medial level showed that L4 had the most concave body. Moreover, L4 had the greatest depth of the spinal canal at the same measurement level. Consequently, in guinea pigs, the greatest load is in the L4 region, unlike in humans, where, due to the axial load of the spinal column, the highest pressure is exerted on the last lumbar vertebrae.
... 1,3,12,13 Despite these promising outcomes, first-generation articulating balland-socket disc replacements cannot mimic the complex deformational kinematics of natural IVDs. [14][15][16] The design of these first-generation prostheses is often derived from large synovial joint arthroplasties and thus is mainly based on sliding motions, whereas the natural IVD allows motion based on deformation. 17,18 Previous research has shown that, a first-generation ball-and-socket implant could not reproduce the kinematic signature of an intact spinal segment, unlike a second-generation with a deformable viscoelastic component. ...
... [19][20][21] Although these second-generation devices are already an improvement when compared to first-generation devices, none of the currently available implants can mimic the osmotic swelling pressure known to be crucial for the biomechanical properties of the IVD tissue, needed to provide its compressive resistance. 14,17 To better replicate the biomechanical properties of the natural IVD, a biomimetic artificial IVD (bioAID) was developed. 22,23 This novel prosthesis mimics a number of aspects of the native structure of the IVD and aims to mimic its biomechanical properties. ...
Background Context
Cervical disc replacement (CDR) aims to restore motion of the treated level to reduce the risk of adjacent segment disease (ASD) compared with spinal fusion. However, first‐generation articulating devices are unable to mimic the complex deformation kinematics of a natural disc. Thus, a biomimetic artificial intervertebral CDR (bioAID), containing a hydroxyethylmethacrylate (HEMA)—sodium methacrylate (NaMA) hydrogel core representing the nucleus pulposus, an ultra‐high‐molecular‐weight‐polyethylene fiber jacket as annulus fibrosus, and titanium endplates with pins for primary mechanical fixation, was developed.
Purpose
To assess the initial biomechanical effect of the bioAID on the kinematic behavior of the canine spine, an ex vivo biomechanical study in 6‐degrees‐of‐freedom was performed.
Study Design
A canine cadaveric biomechanical study.
Methods
Six cadaveric canine specimens (C3‐C6) were tested in flexion‐extension (FE), lateral bending (LB) axial rotation (AR) using a spine tester in three conditions: intact, after C4‐C5 disc replacement with bioAID, and after C4‐C5 interbody fusion. A hybrid protocol was used where first the intact spines were subjected to a pure moment of ±1 Nm, whereafter the treated spines were subjected to the full range of motion (ROM) of the intact condition. 3D segmental motions at all levels were measured while recording the reaction torsion. Biomechanical parameters studied included ROM, neutral zone (NZ), and intradiscal pressure (IDP) at the adjacent cranial level (C3‐C4).
Results
The bioAID retained the sigmoid shape of the moment‐rotation curves with a NZ similar to the intact condition in LB and FE. Additionally, the normalized ROMs at the bioAID‐treated level were statistically equivalent to intact during FE and AR while slightly decreased in LB. At the two adjacent levels, ROMs showed similar values for the intact compared to the bioAID for FE and AR and an increase in LB. In contrast, levels adjacent to the fused segment showed an increased motion in FE and LB as compensation for the loss of motion at the treated level. The IDP at the adjacent C3‐C4 level after implantation of bioAID was close to intact values. After fusion, increased IDP was found compared with intact but did not reach statistical significance.
Conclusion
This study indicates that the bioAID can mimic the kinematic behavior of the replaced intervertebral disc and preserves that for the adjacent levels better than fusion. As a result, CDR using the novel bioAID is a promising alternative treatment for replacing severely degenerated intervertebral discs.
... residual or recurrent pain up to twelve months after the initial complaints. 1 The cervical spine is the most mobile part of the spine with over 600 movements per hour in a normal individual and the maximum flexion and extension occur at C5/C6 disc level. [2][3][4] The Intervertebral disc (IVD) is a very complicated structure that plays a very vital role in the movement of the spine and is comprised of two parts, the tough but flexible outer Annulus fibrosus (AF) and centrally located Nucleus pulposus (NP) which is responsible for shock absorption and prevent vertebral bone friction. ...
... Other risk factors associated with this condition include obesity, smoking, and other environmental factors. 4,[7][8][9][10] Magnetic resonance imaging (MRI) scan is considered globally as the most sensitive test for detecting degenerative disc abnormalities associated with neck pain. Other imaging modalities include conventional plain radiography and Computed tomography (CT) scan. ...
Background: Neck pain is a common global health problem causing significant individual disability and socioeconomic burden on health care facilities. Many factors have been associated with neck pain but the most implicated is the cervical intervertebral disc disease. Magnetic resonance imaging (MRI) scan is considered globally as the most sensitive test for detecting degenerative disc abnormalities associated with neck pain. The objective of this study was to evaluate cervical disc changes on MRI in non-traumatic symptomatic subjects and to accumulate baseline data on the pattern of changes.Methods: A four-years retrospective review of 115 patients (age range 13 to 81 years) who had a cervical MRI scan due to non-traumatic neck and radiating shoulder pain from September 2017 to February 2021 at the Radiology Department of Jos University Teaching Hospital North Central Nigeria. All the patients were scanned using a Single Siemens (Magnetom Concerto) MRI scanner with 0.2T magnetic field strength. Sagittal T1-weighted and T2-weighted fast spin-echo images were acquired, and axial images and contrast-enhanced studies were done only when required.Results: The study included 74 (64.3%) males and 41 (35.7%) females with a mean age of 50.7±13.2 and a modal age group of 41-60 years. The normal intervertebral disc was commonest at C2/C3 followed by C6/C7 level while degenerative disc changes were most commonly seen at C4/C5 followed by C5/C6 level. The majority (93%) of patients had multilevel intervertebral disc changes and the most frequent and severe occurrences of intervertebral disc dehydration, bulge, herniation, and disc space narrowing were noted at C4/C5 (79.1%), C4/C5 (12.2%), C5/C6 (59.1%) and C4/C5 (10.4%) respectively.Conclusions: This study found all patients examined had at least one level of intervertebral disc changes with the majority having multilevel involvement (93%). The most commonly and severely affected level was C4/C5 followed by C5/C6 level. The most frequent and severe occurrences of disc desiccation, bulge, herniation (protrusion/extrusion/sequestration) and disc height reduction were noted at C4/C5 (79.1%), C4/C5 (12.2%), C5/C6 (59.1%) and C4/C5 (10.4%) respectively.
... Some of the commonly used segmentation techniques are atlas-based segmentation [3], region-based segmentation [4], and active contour-based segmentation [5]. A spine segmentation procedure that creates anatomically correct 3D models can be hindered by certain factors such as the anatomic complexity of the spine, image noise, low intensity, and the partial volume effect [6]. Vertebrae recognition refers to the process of identifying and labeling individual vertebrae from segmented spine images. ...
Spine image analysis is based on the accurate segmentation and vertebrae recognition of the spine. Several deep learning models have been proposed for spine segmentation and vertebrae recognition, but they are very computationally demanding. In this research, a novel deep learning model is introduced for spine segmentation and vertebrae recognition using CT images. The proposed model works in two steps: (1) A cascaded hierarchical atrous spatial pyramid pooling residual attention U-Net (CHASPPRAU-Net), which is a modified version of U-Net, is used for the segmentation of the spine. Cascaded spatial pyramid pooling layers, along with residual blocks, are used for feature extraction, while the attention module is used for focusing on regions of interest. (2) A 3D mobile residual U-Net (MRU-Net) is used for vertebrae recognition. MobileNetv2 includes residual and attention modules to accurately extract features from the axial, sagittal, and coronal views of 3D spine images. The features from these three views are concatenated to form a 3D feature map. After that, a 3D deep learning model is used for vertebrae recognition. The VerSe 20 and VerSe 19 datasets were used to validate the proposed model. The model achieved more accurate results in spine segmentation and vertebrae recognition than the state-of-the-art methods.
... Foreign materials such as metal implants [4], bone grafts [5], or synthetic materials [6] are often used in spinal fusion procedures to promote bone growth and fusion between the vertebrae [7]. These materials are intended to provide stability and support to the spine as it heals [8]. However, the use of foreign materials in spinal fusion procedures can trigger a foreign body reaction [9], which is an immune system response to the presence of foreign materials in the body [10]. ...
Spinal fusion surgery is a common procedure used to stabilize the spine and treat back pain. The procedure involves the use of foreign materials such as screws, rods, or cages, which can trigger a foreign body reaction, an immune response that involves the activation of immune cells such as macrophages and lymphocytes. The foreign body reaction can impact the success of spinal fusion, as it can interfere with bone growth and fusion. This review article provides an overview of the cellular and molecular events in the foreign body reaction, the impact of the immune response on spinal fusion, and strategies to minimize its impact. By carefully considering the use of foreign materials and optimizing surgical techniques, the impact of the foreign body reaction can be reduced, leading to better outcomes for patients.
... CEP is essential to maintain the mechanical integrity of the IVD and the exchange of nutrients (Zhang X. B. et al., 2021). Essential substances such as glucose and oxygen permeate into the NP mainly through the CEP to maintain IVD activity (Frost et al., 2019). ECM is present in the extracellular environment of all tissues. ...
Intervertebral disc degeneration is thought to be a major contributor to low back pain, the etiology of which is complex and not yet fully understood. To compensate for the lack of drug and surgical treatment, mesenchymal stem cells have been proposed for regenerative treatment of intervertebral discs in recent years, and encouraging results have been achieved in related trials. Mesenchymal stem cells can be derived from different parts of the body, among which mesenchymal stem cells isolated from the fetal umbilical cord have excellent performance in terms of difficulty of acquisition, differentiation potential, immunogenicity and ethical risk. This makes it possible for umbilical cord derived mesenchymal stem cells to replace the most widely used bone marrow-derived and adipose tissue derived mesenchymal stem cells as the first choice for regenerating intervertebral discs. However, the survival of umbilical cord mesenchymal stem cells within the intervertebral disc is a major factor affecting their regenerative capacity. In recent years biomaterial scaffolds in tissue engineering have aided the survival of umbilical cord mesenchymal stem cells by mimicking the natural extracellular matrix. This seems to provide a new idea for the application of umbilical cord mesenchymal stem cells. This article reviews the structure of the intervertebral disc, disc degeneration, and the strengths and weaknesses of common treatment methods. We focus on the cell source, cell characteristics, mechanism of action and related experiments to summarize the umbilical cord mesenchymal stem cells and explore the feasibility of tissue engineering technology of umbilical cord mesenchymal stem cells. Hoping to provide new ideas for the treatment of disc degeneration.
... The results showed that female motion segments exhibited more motion during lateral bending, flexion, and extension. Studies have also shown that increased spinal segment motion can cause excessive wear and tear [19] potentially resulting in a higher incidence of facet joint arthrosis. ...
Objectives
Facet joint arthrosis is a common radiologic finding but remains controversial as a source of low back pain. We conducted a study to evaluate some of the potential risk factors contributing to the development of facet joint arthrosis, such as age, gender, and body mass index (BMI). The study aimed at establishing an association between these factors and facet joint arthrosis in the Ghanaian population, as a foundation for further research on low back pain.
Materials and Methods
This was a retrospective study done at the Department of Radiology, Korle Bu Teaching Hospital from January 2019 to December 2021. The study population included all cases referred to our department with complaints of low back pain. Patients below 18 years and those with a history of congenital lesions, trauma, infection, and malignancies were excluded. A total of 1017 cases were identified with facet joint arthrosis. The mean difference in age and BMI between males and females was compared using an independent sample t -test. Statistical association was done using Pearson’s Chi-square test. P ≤ 0.05 was used as statistical significance.
Results
Majority of the study subjects were overweight with a mean BMI of 27.31 ± 5.37 kg/m ² . The mean age was 53.61 ± 16.22 years, and majority were within the age of 51–60 years. Age was significantly associated with the prevalence of facet joint arthrosis.
Conclusion
The prevalence of facet joint arthrosis is significantly associated with increasing age but not with the BMI. Lumbar facet joint arthrosis is more prevalent in women than in men, which may be due to the sensitivity of cartilage to female sex hormones.
... The spine, or vertebral column, is an important bony structure that connects the head to the pelvis [1]. Abnormal spinal curvature may cause lower back pain [2] and neck pain [3][4][5][6] and, in severe cases, obvious body imbalance and even cardiorespiratory complications [7]. ...
The spine is an important part of the human body. Thus, its curvature and shape are closely monitored, and treatment is required if abnormalities are detected. However, the current method of spinal examination mostly relies on two-dimensional static imaging, which does not provide real-time information on dynamic spinal behaviour. Therefore, this study explored an easier and more efficient method based on machine learning and sensors to determine the curvature of the spine. Fifteen participants were recruited and performed tests to generate data for training a neural network. This estimated the spinal curvature from the readings of three inertial measurement units and had an average absolute error of 0.261161 cm.
... As can be seen from the bursting strength data, all textile patterns only failed above the previously measured hydrogel swelling pressure tested in a rigidly confined compression setup of 1 MPa [18]. Also being above the physiological internal pressures measured for natural nucleus pulposus that ranges between 0.3and 1 MPa [12,[21][22][23]. This is also consistent with the results of the swelling and compression test of the full device, where no macroscopical damage of the fiber jacket was observed. ...
As an attempt to better replicate the complex kinematics of a natural disc, a novel biomimetic artificial intervertebral disc replacement (bioAID) has been developed containing a swelling hydrogel core as nucleus pulposus, a fiber jacket as annulus fibrosus and metal endplates to connect the device to the adjacent vertebrae. The first prototype consisted of a weft-knitted fiber jacket, in which only a single fiber was used to create the jacket structure. This can endanger the structural integrity of the complete device upon yarn damage. Therefore, in this study, several warp-knitted textile structures were assessed to (1) ensure structural integrity, (2) while allowing for swelling constraint of the hydrogel and (3) behaving as one integrated unit similar to the natural IVD. Moreover, the fiber jacket should (4) act as a scaffold that allows bone ingrowth to ensure long-term stability and (5) have a good durability, (6) be wear resistant and (7) have good manufacturing feasibility with good quality control. In this study, 4 different stitch patterns, including 2 × 1 and 1 × 1 lapping with and without a pillar stitch, were produced. The effect of the stitch pattern and stitch density on the fabric mechanical properties and device swelling and compressive strength was assessed. As a next step, the effect of using multiple layers of fabrics, mimicking the layered structure of annulus fibrosus, on the functional capacity of the bioAID was characterized. All textile structures were capable of limiting the swelling of the hydrogel while withstanding its internal pressure and showing sufficient wear resistance. However, only the 2 × 1 and 2 × 1 with pillar stitch had a pore size range that was suitable for cell infiltration to facilitate osseointegration as well as having the highest strength of the complete device to ensure safety under compression loading. Incorporating different number of jacket layers of these two stitch patterns did not show any significant effect. When also taking the structural parameters into consideration, the 2 × 1 lapping design with 4 layers was able to constrain hydrogel swelling, provide a high compressive strength, could facilitate cell infiltration and had dimensions within the range of a natural intervertebral disc.
... The two end plates are composed of hyaline cartilage superiorly and inferiorly. Changes in the collagen content contained in the intervertebral discs occur naturally based on an aging process called intervertebral disc degeneration [13][14][15][16]. ...
Background: Nucleus Pulposus Herniation (NPH) is a disease in which the annulus fibrosus ruptures, causing the nucleus pulposus to protrude or bulge and press against the spinal canal, causing sciatic pain. One of the risk factors for Nucleus pulposus herniation was Body Mass Index (BMI). Objective: This study aim the relationship between BMI and the incidence of Lumbar Disc Herniation (LDH) patients at UKI General Hospital from January to June 2020. Methods: The subjects of the study were 24 patients with lumbar disc herniation who were treated at UKI General Hospital from January to June 2020 that were taken from medical records. Results: 63 samples were analyzed that obtained 24 (38.0%) patients with lumbar disc herniation, and patients with lumbar disc herniation with BMI ≥ 23 as many as 18 subjects (75.0%). Conclusion: There is no significant relationship between BMI and LDH patients at UKI General Hospital.
... The embroidered patches were each composed of five layers of silk yarn. The distance of the yarn deposit was set at 0.7 mm, and the silk yarn in each layer was embroidered with alternating orientations of −30 • and +30 • on the water soluble embroidery ground "Solvy Fabric No. 41825" (company: Gunold GmbH, Stockstadt, Germany) according to the natural arrangement [28]. For both the upper and the lower yarn, the same silk yarn was used. ...
Intervertebral disc (IVD) herniation often causes severe pain and is frequently associated with the degeneration of the IVD. As the IVD degenerates, more fissures with increasing size appear within the outer region of the IVD, the annulus fibrosus (AF), favoring the initiation and progression of IVD herniation. For this reason, we propose an AF repair approach based on methacrylated gellan gum (GG-MA) and silk fibroin. Therefore, coccygeal bovine IVDs were injured using a biopsy puncher (⌀ 2 mm) and then repaired with 2% GG-MA as a filler material and sealed with an embroidered silk yarn fabric. Then, the IVDs were cultured for 14 days either without any load, static loading, or complex dynamic loading. After 14 days of culture, no significant differences were found between the damaged and repaired IVDs, except for a significant decrease in the IVDs’ relative height under dynamic loading. Based on our findings combined with the current literature that focuses on ex vivo AF repair approaches, we conclude that it is likely that the repair approach did not fail but rather insufficient harm was done to the IVD.
... Based on the natural structure of the AF in the lumbar spine section (according to Frost et al. [30]), guideline values for the structure of the fibrous ring were determined. With a fiber orientation of +30 and −30 degrees, the structure of the single layer was created in SolidWorks as a contour line with the specified dimensions (length: 389.55 mm; height 10 mm) and the drawing was exported as a dxf-file. ...
Low back pain is often due to degeneration of the intervertebral discs (IVD). It is one of the most common age- and work-related problems in today’s society. Current treatments are not able to efficiently restore the full function of the IVD. Therefore, the aim of the present work was to reconstruct the two parts of the intervertebral disc—the annulus fibrosus (AF) and the nucleus pulposus (NP)—in such a way that the natural structural features were mimicked by a textile design. Silk was selected as the biomaterial for realization of a textile IVD because of its cytocompatibility, biodegradability, high strength, stiffness, and toughness, both in tension and compression. Therefore, an embroidered structure made of silk yarn was developed that reproduces the alternating fiber structure of +30° and −30° fiber orientation found in the AF and mimics its lamellar structure. The developed embroidered ribbons showed a tensile strength that corresponded to that of the natural AF. Fiber additive manufacturing with 1 mm silk staple fibers was used to replicate the fiber network of the NP and generate an open porous textile 3D structure that may serve as a reinforcement structure for the gel-like NP.
... In the intact spine, the Young elastic modulus is 1.66 MPa for the nucleus pulposus, 12.99 MPa for the annulus, 3.87 MPa for the cancellous bone, and 14.64 MPa for the cortical bone [19]. Furthermore, the Poisson ratio is 0.40 for the nucleus pulposus and 0.35 for the annulus [19], and the intact disc stands loads between 800 and 3000 N [20,21]. Accordingly, our TDR should have an elastic modulus similar to the cortical vertebral body bone (14.64 MPa) (under heavy loads, the bone collapses before the intervertebral disc), a Poisson ratio of 0.40, and stand a minimum 3000 N load. ...
The intact intervertebral disc is a six-freedom degree elastic deformation structure with shock absorption. “Ball-and-socket” TDR do not reproduce these properties inducing zygapophyseal joint overload. Elastomeric TDRs reproduce better normal disc kinematics, but repeated core deformation causes its degeneration. We aimed to create a new TDR (ADDISC) reproducing healthy disc features. We designed TDR, analyzed (Finite Element Analysis), and measured every 500,000 cycles for 10 million cycles of the flexion-extension, lateral bending, and axial rotation cyclic compression bench-testing. In the inlay case, we weighted it and measured its deformation.ADDISC has two semi-spherical articular surfaces, one rotation centre for flexion, another for extension, the third for lateral bending, and a polycarbonate urethane inlay providing shock absorption. The first contact is between PCU and metal surfaces. There is no metal-metal contact up to 2000 N, and CoCr28Mo6 absorbs the load. After 10 million cycles at 1.2–2.0 kN loads, wear 140.96 mg (35.50 mm3), but no implant failures. Our TDR has a physiological motion range due to its articular surfaces' shape and the PCU inlay bumpers, minimizing the facet joint overload. ADDISC mimics healthy disc biomechanics and Instantaneous Rotation Center, absorbs shock, reduces wear, and has excellent long-term endurance.
... [3] The cervical foramen is surrounded anteriorly by the superior and inferior vertebral bodies, and the intervertebral disc is covered with posterior longitudinal ligament, posteriorly by the superior and inferior facets, and cephalad and caudad by pedicles. [4] Cervical radiculopathy is a dysfunction of a nerve root in the cervical spine, and it is a disorder with various mechanisms of pathology and the two main mechanisms of the nerve root irritation or impingement are degeneration of cervical spondylosis which leads to stenosis or bony spurs and is most commonly seen in older patients and disc herniation which is more common in younger patients [5] with or without extruded disc fragments. C7 nerve root is most commonly affected nerve root due to disc herniation, as compared to C6 nerve root. ...
AIM: The main aim of this study was to evaluate functional disability in patients with cervical radiculopathy. Our second aim was to compare neck disability between males and females.
METHODS: The study included 35 participants of both sexes, in which 21 were female and 14 male. We have used three scales for the evaluation of neck disability: (1) Cervical radiculopathy Impact Scale (CRIS), (2) Neck Pain and Disability (NPAD) Scale, and (3) Copenhagen Neck Functional Disability (CNFD) Scale.
RESULTS: The mean scores of CRIS were 14.35 ± 15.59 in males and 33.22 ± 17.58 in females. The NPAD Scale scores were 14.35 ± 15.59 in males and 33.22 ± 17.58 in females. The mean scores of the CNFD Scale were 7.92 ± 5.56 in males and 13.50 ± 5.61 in females. All three scales showed a significant difference between the scores of the two genders, indicating more disability in female patients as compared with the male patients.
CONCLUSION: Our results showed 26.22% and 25.88% disability as per CRIS and Neck Pain and Disability Scale, respectively. We found mild-to-moderate disability in our subjects according to the CNFD Scale. The study concluded that females have more disability in cervical radiculopathy as compared to males.
... Lumbar is located at the lower part of the spine and has a function to support the upper body and protect the spinal cord (Frost et al., 2019). Due to its heavy functions, lumbar is prone to be injured and surgery is required to restore its function. ...
Lumbar model is an artificial bone that is commonly used in
surgical training to simulate working with the human-like bone for the trainer.
The common lumbar model is made of rigid polyurethane (PU) foam and is produced
using casting. However, the current lumbar model is expensive and has
limitations in representing the real human lumbar, especially in geometry,
visuals, and haptics. Therefore, an alternative method of fabricating lumbar
models made of rigid polyurethane for surgical training using indirect additive
manufacturing will be investigated in this paper. The proposed indirect
additive manufacturing is a combination of 3D printing and casting methods. The
main process of this method is started by fabricating a mold made of polyvinyl
alcohol (PVA) using fused deposition modeling (FDM) 3D printing and
subsequently casting PU foam material into the 3D printed PVA mold.
Accordingly, the aim of this study is to find the optimized casting process
parameters, especially for injecting the material into the mold, to achieve a
better quality of lumbar model. The study was conducted using a Design of
Experiment (DoE) Taguchi Orthogonal Array to optimize the casting process. The
geometrical measurements of middle end-plate depth, upper end-plate width,
spinal canal width, spinal canal depth, and lower pedicle length show the error
ranged from 0.14% to 0.85%. The average porosity, measured from the body,
lamina, and spinous, was found to be non-uniform. It is ranged from 19.58% to
21.94% on the middle part and 39.78% to 45.41% on the subsurface of lumbar
model. The density was increased by 64.89% compared to the reference open
molded PU foam.
... The spine represents the bony structure housing the spinal cord, which, in addition to protecting this essential part of the central nervous system, is responsible for supporting body weight, withstanding external forces, and allowing for mobility and flexibility while dissipating energy and protecting against impact [1,2]. Unfortunately, the spine is also prone to various diseases, spinal disorders being among the most frequent and expensive medical conditions [3]. ...
Spine tumors represent a significant social and medical problem, affecting the quality of life of thousands of patients and imposing a burden on healthcare systems worldwide. Encompassing a wide range of diseases, spine tumors require prompt multidisciplinary treatment strategies, being mainly approached through chemotherapy, radiotherapy, and surgical interventions, either alone or in various combinations. However, these conventional tactics exhibit a series of drawbacks (e.g., multidrug resistance, tumor recurrence, systemic adverse effects, invasiveness, formation of large bone defects) which limit their application and efficacy. Therefore, recent research focused on finding better treatment alternatives by utilizing modern technologies to overcome the challenges associated with conventional treatments. In this context, the present paper aims to describe the types of spine tumors and the most common current treatment alternatives, further detailing the recent developments in anticancer nanoformulations, personalized implants, and enhanced surgical techniques.
... The anatomy of the human neck is a group of four compartments; vertebral, visceral and two vascular compartments. 1 Any abnormality, inflammation, or harm to the supporting structures, like ligaments, and muscles, can cause neck pain. 2 Neck pain is the fourth most leading cause of disability and musculoskeletal disorder after disability-adjusted life years (DALYs) globally after heart disease, lower respiratory tract infection and cardiovascular diseases. 3 Kinematically, the human neck is mostly affected by poor posture, which may lead to muscular imbalance. ...
Neck pain is the fourth leading cause of disability, and is the most common musculoskeletal disorder. High-heel shoes, one of the significant identities of females, cause pain in the neck as well as in feet and ankle regions. The current narrative review was planned to explore evidence to highlight the biomechanical factors of high-heel shoes as the source of neck pain, which mostly remains undiagnosed. PubMed and Google Scholar search engines were explored for full text of research articles published in English language from 2016 to 2021. Of the 82 studies initially found, 22(27%) were shortlisted for full-text assessment, and, of them, 6 (27.27%) were selected for detailed analysis. Despite other contributing factors, kinematics and kinetics should be considered primarily during neck pain management. Based on best available evidence, high heels increase the individual’s height, but result in significant decrease in trunk flexion.
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... Pathological changes in the ligamentum flavum can lead to severe myelopathy, radiculopathy, and other degenerative spinal problems characterized by reduced elasticity, obvious thickening, or worsened ossification. 1) The yellow ligamentum and intervertebral disks consist of elastin, a highly specialized protein in connective tissues such as the skin, lungs, and blood vessels. 2) The normal LF is histologically composed of 80% elastic and 20% collagen fibers. ...
... [1] Their function is to offer interlocking mechanically and puts the nucleus pulposus and bulging into the middle part of the vertebra. [2] Vertebral endplates are the hardest part of the intervertebral disc, however, they fail to work once there is fracture of the body of the vertebra. [3] They provide nutrition to the intervertebral disc by offering the nucleus pulposus and annulus fibrosus with the components, which preserve the intervertebral disc, keep them flourishing, and also prevent their degeneration. ...
... First generation LTDR implants were designed based on knee and hip, steel and ball arthroplasty technology (11). However, these modular devices lack the natural compressibility and elasticity of a physiologic intervertebral disc (12). Such devices include the Maverick (Medtronic), Charite (DePuy Spine Inc), Prodisc-L (Centinel Spine) and Table 2 Comparison of baseline (n=60), 6-week (n=60), 6-month (n=60), and final follow-up (n=37) patient reported outcome measures data (VAS, ODI, and physical/mental SF-12). ...
Background:
The motion preserving benefits of lumbar total disc replacement (LTDR) are well established. There is a paucity of long-term follow-up data on the M6-L prosthesis. The aim was to evaluate the clinical and radiographic outcomes of patients undergoing LTDR with M6-L and make comment about its effectiveness and durability.
Methods:
A retrospective single center chart review was performed of all patients who underwent LTDR with M6-L between January 1, 2011, and January 1, 2021, either as standalone device or combined with a caudal anterior lumbar interbody fusion (ALIF) (hybrid procedure). Preoperative, postoperative, and final follow-up patient reported outcome measures (PROMs) (VAS back, VAS leg, ODI, and SF-12) and patient satisfaction were recorded prospectively. Device range of motion (ROM), adjacent segment degeneration/disease and heterotopic ossification (HO) were obtained from flexion and extension lumbar radiographs at most recent follow-up.
Results:
Sixty patients underwent LTDR with the M6-L device. Mean age was 41 [16-71] years and 38 (63%) were male. Sixteen (26.7%) underwent standalone LTDR, 42 (70.0%) a hybrid procedure, and 2 (3.3%) a 3-level procedure. Twenty-three (38.3%) patients were lost to follow-up. Thirty-seven (61.7%) were followed for a mean of 4.3 [1-10] years with 36/37 reviewed at a minimum of 2-years and 13/37 followed for over 5-years. Only one patient with osteopenia needed index level revision LTDR surgery for subsidence requiring supplemental posterior instrumentation. There were no osteolysis induced device related failures. Thirty patients obtained long-term follow-up radiographic data. Six patients had adjacent segment degeneration; none required surgery for adjacent segment disease (ASD). Three patients presented with clinically significant HO (2 with McAfee class III, 1 with class IV). The average M6-L ROM was 8.6 degrees. Mean preoperative baseline PROMs demonstrated statistically significant improvements postoperatively and were sustained at last follow-up (P<0.05).
Conclusions:
Total disc replacement (TDR) with M6-L showed clinically significant improvement in PROMs that were sustained at long-term follow-up. There were no osteolysis induced device related failures. The device ROM was maintained and showed a downward trend over the 10-year study follow-up period. This paper demonstrated that the M6-L was an effective and durable arthroplasty device in this series.
... Anteriorly, vertebral bodies look round. The spinal cord finishes between the first and second lumbar vertebrae [13]. Different regions of the vertebral column have different vertebrae. ...
Objective: Low back pain (LBP) is one of the top ten causes of visits to hospitals. Literature review shows that 84% of people have low back pain at some stages of their lives. Therefor the present research study was conducted to find out the prevalence of pathologies causing low back pain using Magnetic Resonance Imaging.
Methods: This was a cross-sectional study conducted in a private tertiary care hospital Peshawar. The sample size was 142, calculated by Rao Soft calculator. The study was conducted during May-August 2020. Data were collected from patients coming to the radiology department for lumber scan MRI and analysed by SPSS version 22.
Results: A total of 142 patients having low back pain including 73 male and 69 females were examined. Degenerative disc diseases (82.3%) were the commonest pathologies. There were a total of 117(82.3%) cases of degenerative disc disease, 09 (6.33%) cases of the traumatic lesion, 08 (5.63%) cases of the congenital lesion, and 5 (3.5%) patients with neoplastic lesions. In this study, there were 44 cases of spinal stenosis, 68 cases of nerve compression. The commonest type of herniation was disc bulge (81.30%) and the most affected lumbar vertebral level by disc bulge was LV4/LV5.
Conclusions: This population-based study shows the prevalence of pathologies causing low back. Males were more affected as compared to females and people with Middle Ages were at increased risk of experiencing low back pain. Degenerative disc diseases (82.3%) were the commonest pathologies, followed by traumatic lesion (6.33%), congenital lesions (5.63%), and neoplastic lesions (3.52%). Future studies with long-term follow-up for determining the benefits of treatments are warranted.
... Hydrogels with and without AG were also studied due to the considerable enhancement of compressive strength they were able to achieve (Figure 6) and the fact that AG is commonly used in spinal fusion procedures. 24,25 was not certified by peer review) is the author/funder. All rights reserved. ...
Lower back pain is a considerable medical problem that will impact 80% of the U.S. population at some point in their life. For the most severe cases, surgical repair is necessary and is associated with costs upwards of $10.2 billion annually in the United States. To alleviate back pain, spine fusions are a common treatment in which two or more vertebrae are biologically fused together often through the use of a graft material. Unfortunately, iliac crest bone autograft, the current gold standard graft material, can yield insufficient fusion and is associated with considerable donor site morbidity and pain as well as limited supply. Therefore, new materials need to be developed in order to better coordinate healing and new bone growth in the affected area to reduce unnecessary patient burden. In order to address this issue, the incorporation of allograft and one of two types of cellulose (i.e., 0CNCs and CNFs) into a dual-crosslinked chitosan hydrogel loaded with bioactive calcium phosphate was investigated. Hydrogels were then tested for both their material and biological properties. Specifically, hydrogel swelling ratio, mass loss, ion release profile, compressive strength, in vitro biocompatibility and osteoinduction as well as in vivo biocompatibility, and effectiveness in a spine fusion model were determined. Cellulose and allograft incorporation significantly improved hydrogel compressive strength and biocompatibility and CNFs were found to be a significantly more biocompatible form of cellulose than 0CNCs. Additionally, through the controlled delivery of osteoinductive simple signaling molecules (i.e., calcium and phosphate ions), DCF-loaded CNF/Chitosan hydrogels were able to induce osteoblast-like activity in murine mesenchymal stem cells. When evaluated in vivo, these hydrogels were found to be non-toxic though the subacute phase (14 days). A 6-week rabbit spine fusion found these materials to achieve near complete fusion when assessed radiographically. This research provides considerable support for the utility of our novel material for spine fusion procedures as well as other future bone applications.
... Surgical decompression can relieve the compression of nerve roots or the spinal cord by degenerative tissues and palliate the clinical symptoms. 1 However, the frequent occurrence of failed back surgery syndrome (FBSS, 4%~48%) seriously affects the quality of life of postoperative patients. 2 Epidural adhesion is considered the most common cause of FBSS and involves various degrees of inflammatory infiltration, scar tissue formation, and tissue adhesions in the epidural space. ...
Background:
The frequent occurrence of failed back surgery syndrome (FBSS) seriously affects the quality of life of postoperative lumbar patients. Epidural adhesion is the major factor in FBSS.
Purpose:
A safe and effective antiadhesion material is urgently needed.
Methods:
A superhydrophilic PLGA-g-PVP/PC nanofiber membrane (NFm) was prepared by electrospinning. FTIR was performed to identify its successful synthesis. Scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and water contact angle measurement were performed. CCK-8 assays were performed in primary rabbit fibroblasts (PRFs) and RAW264.7 cells to explore the cytotoxicity of PLGA-g-PVP/PC NFm. Calcein-AM/PI staining was used to measure the adhesion status in PRFs. ELISA was performed to measure the concentrations of TNF-α and IL-10 in RAW264.7 cells. In addition, the anti-epidural adhesion efficacy of the PLGA-g-PVP/PC NFm was determined in a rabbit model of lumbar laminectomy.
Results:
The PLGA-g-PVP/PC NFm exhibited ultrastrong hydrophilicity and an appropriate degradation rate. Based on the results of the CCK-8 assays, PLGA-g-PVP/PC NFm had no cytotoxicity to PRFs and RAW264.7 cells. Calcein-AM/PI staining showed that PLGA-g-PVP/PC NFm could inhibit PRF adhesion. ELISAs showed that PLGA-g-PVP/PC NFm could attenuate lipopolysaccharide-induced macrophage activation. In vivo experiments further confirmed the favorable anti-epidural adhesion effect of PLGA-g-PVP/PC NFm and the lack of a strong inflammatory response.
Conclusion:
In this study, PLGA-g-PVP/PC NFm was developed successfully to provide a safe and effective physical barrier for preventing epidural adhesion. PLGA-g-PVP/PC NFm provides a promising strategy for preventing postoperative adhesion and has potential for clinical translation.
... In addition, the smallest height available for the M6-C prosthesis is 6 mm, while the height of a natural disc may vary between 3.5 and 6.1 mm. [31][32][33] As such, the height of the prosthesis and the need for significant tissue removal during endplate preparation likely contributed to the greater anterior and posterior disc height observed for the M6-C prosthesis. It has been postulated that excessive anterior/posterior disc height (over-distraction) may result in worsened clinical outcomes through stretching of facet joints. ...
Introduction:
Cervical total disc replacement (CTDR) is an alternative to anterior cervical discectomy and fusion for select patients that may preserve range of motion and reduce adjacent segment disease. Various CTDR prostheses are available; however, comparative data are limited. This study aimed to compare the short-term kinematic and radiological parameters of the M6-C, Mobi-C, and the CP-ESP prostheses.
Methods:
This retrospective cohort study included patients treated with CTDR between March 2005 and October 2020 at a single institution. Patients were included if their follow-up assessment included lateral erect and flexion/extension radiographs. The primary outcome assessed at 3-months postoperatively was range of motion, measured by the difference in functional spinal unit angle between flexion and extension.
Results:
A total of 131 CTDR levels (120 patients, 46.2 ± 10.1 years, 57% male) were included. Prostheses implanted included the M6-C (n = 52), Mobi-C (n = 54), and CP-ESP (n = 25). Range of motion varied significantly (8.2° ± 4.4° vs. 10.9° ± 4.7° vs. 6.1° ± 2.7°, P < 0.001). On post hoc analysis, the Mobi-C prosthesis demonstrated a significantly greater range of motion than either the M6-C prosthesis (P = 0.003) or CP-ESP (P < 0.001).
Conclusion:
Although the optimal range of motion for CTDR has not been established, short-term differences in the range of motion may guide the selection of CTDR prosthesis. Further studies with longer follow-up and consideration of clinical outcome measures are necessary.
... For example, joint braking and non-steroidal antiinflammatory drugs are early treatments for osteoarthritis (133,134). Patients with lumbar spine degeneration should rest in bed to relieve spinal pressure (135,136). Stent implantation can correct local disordered hemodynamics and effectively delay the progression of atherosclerosis (62,137). Piezo1 channel provides solid theoretical support for these clinical prevention measures. ...
Mechanical damage is one of the predisposing factors of inflammation, and it runs through the entire inflammatory pathological process. Repeated or persistent damaging mechanical irritation leads to chronic inflammatory diseases. The mechanism of how mechanical forces induce inflammation is not fully understood. Piezo1 is a newly discovered mechanically sensitive ion channel. The Piezo1 channel opens in response to mechanical stimuli, transducing mechanical signals into an inflammatory cascade in the cell leading to tissue inflammation. A large amount of evidence shows that Piezo1 plays a vital role in the occurrence and progression of chronic inflammatory diseases. This mini-review briefly presents new evidence that Piezo1 responds to different mechanical stresses to trigger inflammation in various tissues. The discovery of Piezo1 provides new insights for the treatment of chronic inflammatory diseases related to mechanical stress. Inhibiting the transduction of damaging mechanical signals into inflammatory signals can inhibit inflammation and improve the outcome of inflammation at an early stage. The pharmacology of Piezo1 has shown bright prospects. The development of tissue-specific Piezo1 drugs for clinical use may be a new target for treating chronic inflammation.
... The intervertebral disc has a complex structure, which results in a redistribution of stresses in the vertebrae. Such damping properties of the intervertebral disc prevent premature wear of the vertebrae (Frost et al., 2019). Usually, such in-vitro methods as tensile, compression, and indentation tests are used to study the mechanical properties of the materials making up the spine. ...
Degenerative diseases of the spine significantly reduce the quality of human life. The spine consists of vertebral bodies and intervertebral discs. The most degraded are intervertebral discs. To study the factors affecting the damageability of the discs, we propose assessing the stress and strain fields by numerical simulation. The vertebral body consists of a shell (cortical bone tissue) and internal contents (cancellous bone tissue). The intervertebral disc is a complex structural element of the spine, consisting of the nucleus pulposus, annulus fibrosus, and cartilaginous plates. To develop numerical models for vertebrae and intervertebral disc, first, it is necessary to verify and validate the material models. This paper for the first time presents new numerical models based on the movable cellular automation method for the materials of the constituent elements of the lumbar spine, their validation, and verification. The models are validated using tensile, compression, and indentation experiments. A good qualitative and quantitative agreement was found with the data of field experiments from the literature.
... However, only a small percentage of patients require surgery. The vast majority qualify for conservative treatment aimed at reducing both the pain and the negative consequences to physical fitness (Colombini, Lombardi, Corsi, Banfi, 2008;Roughley, 2004;Frost, Camarero-Espinosa, Foster, 2019). When long-term pain contributes to the occurrence of chronic discomfort in the sacral spine and the entire back, treatment and therapy require more time and increased economic outlays (Hodgkinson, Shen, Diwan, Hoyland, Richardson, 2019). ...
Degenerative disc disease (DDD) in the lumbosacral spine is one of the most common causes of pain and the significant associated limitations in physical activity and daily functioning, with the vast majority of patients requiring long-term physiotherapy. Hence, the significance of proper diagnostics, locating the cause of the ailment, implementation of appropriate therapy and prevention.
The aim of the study was to investigate the efficacy of outpatient physiotherapy on reducing pain and improving the function of the lumbosacral spine. The research group comprised 95 people (50 women and 45 men) with an average age of 53 years, all patients with DDD in the lumbosacral spine. They underwent 3 physical treatments: magnetotherapy, laser therapy, and systemic cryotherapy, as well as gymnastic exercises, aimed at improving physical fitness, and strengthening the muscular corset. The research methods included the Schober test, the Thomayer test (finger-ground test), the Visual Analogue Scale scale, Laitinen's pain questionnaire, and calculation of BMI.
Physiotherapeutic treatments significantly reduced the patients' pain symptoms, significantly increased the range of motion in the lumbosacral spine and improved physical fitness. Better results of the therapy were observed in patients with lower BMI.
... Its kyphotic curve allows the spine to bear loads anteriorly and to resist tension posteriorly, protecting the spinal cord while moving or bending the body. Since the thoracic spine provides most of the stability and support for the entire trunk [1], spine deformity resulting from poor posture often occurs in this segment. ...
Inadequate sitting posture can cause imbalanced loading on the spine and result in abnormal spinal pressure, which serves as the main risk factor contributing to irreversible and chronic spinal deformity. Therefore, sitting posture recognition is important for understanding people’s sitting behaviors and for correcting inadequate postures. Recently, wearable devices embedded with microelectromechanical systems (MEMs) sensors, such as inertial measurement units (IMUs), have received increased attention in human activity recognition. In this study, a wearable device embedded with IMUs and a machine learning algorithm were developed to classify seven static sitting postures: upright, slump, lean, right and left bending, and right and left twisting. Four 9-axis IMUs were uniformly distributed between thoracic and lumbar regions (T1-L5) and aligned on a sagittal plane to acquire kinematic information about subjects’ backs during static-dynamic alternating motions. Time-domain features served as inputs to a signal-based classification model that was developed using long short-term memory-based recurrent neural network (LSTM-RNN) architecture, and the model’s classification performance was used to evaluate the relevance between sensor signals and sitting postures. Overall results from performance evaluation tests indicate that this IMU-based measurement and LSTM-RNN structural scheme was appropriate for sitting posture recognition.
... Beyond the outer annulus and deeper into the disc, the nutrients and oxygen passively diffuse to reach the inner AF and NP. 100 In patients with degenerated discs, on the other hand, the associated CEPs have been observed radiographically to undergo structural changes such as increases in both ossification and porosity of the endplate and trabeculae that can impair transport efficiency of essential nutrients to the discs. 42 As a result, a hypoxic environment within the IVDs forces the disc cells to undergo anaerobic metabolism to meet their energy requirements. ...
Lumbar disc degeneration is one of the leading causes of chronic low back pain. The degenerative cascade is often initiated by an imbalance between catabolic and anabolic processes in the intervertebral discs. As a consequence of extracellular matrix degradation, neoinnervation and neovascularization take place. Ultimately, this degenerative process results in disc bulging and loss of nucleus pulposus and water content and subsequent loss of disc height. Most patients respond to conservative management and surgical interventions well initially, yet a significant number of patients continue to suffer from chronic low back pain. Because of the high prevalence of long-term discogenic pain, regenerative biological therapies, including gene therapies, growth factors, cellular-based injections, and tissue-engineered constructs, have attracted significant attention in light of their potential to directly address the degenerative process. Understanding the pathophysiology of degenerative disc disease is important in both refining existing technologies and developing innovative techniques to reverse the degenerative processes in the discs. In this review, we aimed to cover the underlying pathophysiology of degenerative disc disease as well as its associated risk factors and give a comprehensive summary about the developmental, structural, radiological, and biomechanical properties of human intervertebral discs.
Background Polymethylmethacrylate (PMMA) bone cement is extensively used in spinal procedures such as vertebroplasty and kyphoplasty, while its use in percutaneous cement discoplasty (PCD) is not yet widely spread. A main issue for both application sites, vertebra and disc, is the mismatch in stiffness between cement and bone, potentially resulting in adjacent vertebral fractures and adjacent segment disease. Tailoring the cement modulus using additives is hence an interesting strategy. However, there is a lack of data on the tensile and tension-compression fatigue properties of these cements, relevant to the newly researched indication of PCD. Method A commercial PMMA cement (VS) was modified with 12%vol of linoleic acid (VSLA) and tested for quasi-static tensile properties. Additionally, tension-compression fatigue testing with amplitudes ranging from +/-5MPa to +/-7MPa and +/-9MPa was performed, and a Weibull three-parameter curve fit was used to calculate the fatigue parameters. Results Quasi-static testing revealed a significant reduction in VSLA’s Young’s Modulus (E=581.1±126.4MPa) compared to the original cement (E=1478.1±202.9MPa). Similarly, the ultimate tensile stress decreased from 36.6±1.5MPa to 11.6±0.8MPa. Thus, VSLA offers improved compatibility with trabecular bone properties. Fatigue testing of VSLA revealed that as the stress amplitude increased the Weibull mean number decreased from 3591 to 272 and 91 cycles, respectively. In contrast, the base VS cement reached run-out at the highest stress amplitude. However, the lowest stress amplitude used exceeds the pressures recorded in the disc in vivo, and VSLA displayed a similar fatigue life range to that of the annulus fibrosis tissue. Conclusions While the relevance of fully reversed tension-compression fatigue testing can be debated for predicting cement performance in certain spinal applications, the results of this study can serve as a benchmark for comparison of low-modulus cements for the spine. Further investigations are necessary to assess the clinical feasibility and effectiveness of these cements.
Tujuan dari penelitian ini adalah untuk memperoleh informasi mengenai angka kejadian low back pain pada mahasiswa Fakultas Kedokteran Universitas Hasanuddin. Jenis penelitian yang digunakan adalah studi observasional analitik dengan desain cross sectional, teknik pengumpulan sampel adalah simple random sampling, sehingga diperoleh sebanyak 160 responden. Pengumpulan data dilakukan dengan menggunakan kuesioner google form dan kemudian dianalisis dengan program statistik. Hasil penelitian ini menunjukkan dari 160 responden yang memenuhi kriteria inklusi didapatkan sebanyak 120 responden (75%) yang mengalami low back pain, dengan rincian 101 responden (63,1%) mengalami low back pain dengan intensitas sedang (1-2x/bulang), dan 19 responden (11,9%) mengalami low back pain dengan intensitas sering (1-2x/minggu). Kesimpulan dalam penelitian ini menunjukan bahwa angka kejadian low back pain pada mahasiswa dipengaruhi oleh berbagai faktor, seperti jenis kelamin, durasi dan posisi duduk, dan aktivitas fisik olahraga.
Objective: This study aims to determine the risk of low back pain complaints on the incidence of urinary incontinence in pregnant women in Leuwiliang District, Bogor. Methods: This study is case contro . with a total sample of 72 pregnant women (case = 36, control = 36) data collection using the Oswestry Disability Index for Low Back pain questionnaire and Questionnare For Female Urinary Incontinence Diagnosis. Results: The results showed that the incidence or complaints of low back pain was 2.08 times more at risk of urinary incontinence, with a p-value = 0.144. 0.144 is not significant (OR = 2.0805% CI = 0.779-5.552 P = 0.144). 0,144 ). Conclusion: This study shows that there is a risk of complaints of Low back Pain on the incidence of Urinary Incontinence which has a risk of 2.08 times but is not significant statically (P=0,144).
Degeneration of the intervertebral disc (IVD) is a normal part of aging. Due to the spine's declining function and the development of pain, it may affect one's physical health, mental health, and socioeconomic status. Most of the intervertebral disc degeneration (IVDD) therapies today focus on the symptoms of low back pain rather than the underlying etiology or mechanical function of the disc. The deteriorated disc is typically not restored by conservative or surgical therapies that largely focus on correcting symptoms and structural abnormalities. To enhance the clinical outcome and the quality of life of a patient, several therapeutic modalities have been created. In this review, we discuss genetic and environmental causes of IVDD and describe promising modern endogenous and exogenous therapeutic approaches including their applicability and relevance to the degeneration process.
The study of the movement of the vertebrae of the lumbar spine is classified as a relevant theme for research, considering the possibility of exploring the pathological dysfunctions of this region. This paper presents the development of a trajectory motion control for a lumbar spine model. The spine model is being represented by a 2 DOF (Degrees of Freedom) manipulator robot, which represents the motion of two lumbar vertebrae. For the computational simulations of the controlled spine behavior the mathematical dynamic model of the manipulator based on the Lagrange approach is being considered. Preliminary simulation results show that the implemented conventional controller robustly follows the references given for the angles of the vertebrae, guaranteeing the planned movement.KeywordsBiomechanicsMotion controlRobotic lumbar spine
Patients with lumbar disc herniation frequently report experiencing nocturnal back discomfort that interferes with their ability to sleep adequately. This study's objective is to describe and evaluate the pain and sleep quality of individuals with disc herniation diagnoses. Objective: To assess sleep quality and nocturnal pain in patients of lumbar disc herniation. Methods: Patients range from 24-65 years, both males and females with positive straight leg raise and prone knee bending test were selected with random sampling technique. Data were collected after filling a comprehensive questionnaire. PSQI questionnaire was used to access quality of sleep disturbance. Visual analog scale was the tool that used to help the person rate the intensity of pain at night. Results: The results showed that 6(12%) had mild disturbance in sleep, 33(66%) had moderate disturbance in sleep and 11(22%) had severe disturbance in sleep according to global PSQI. Conclusions: According to the findings from our study, lumbar disc herniation has negatively impacted the participants' ability to sleep. Sleep disruption and pain were connected, and nocturnal discomfort affected patient’s activities of daily liv
Sagittal plane deformity can be defined as a deviation from the normal curvature of the spine in the sagittal plane. This deformity can distort the natural shape of the spine and cause posture problems. In recent years, effects such as reduced activity in daily life, increased time spent in front of computers and mobile phones, and inactivity during the recent pandemic have also led to a significant increase in sagittal plane deformity. In this study, 16 healthy and 16 healthy adolescents with sagittal plane deformity participated. Surface EMG (sEMG) recordings were obtained from thoracal kyphosis and lumbar lordosis subjects, which are frequently seen in sagittal plane deformity (SPD) subjects, and healthy subjects. After filtering the raw sEMG data, wavelet packet transform analysis was performed. The energy values of the wavelet packets corresponding to the low and high frequency components have been calculated. Statistical analysis of the analysed data identified channels with significant differences between the two groups. The results showed that SPD subjects showed more muscle activity than healthy subjects and spent more energy to increase the quality of movements and to perform them with the correct muscle dynamics. It has been observed that SPD subjects develop compensations from different muscle regions in order to perform movements correctly due to postural changes. In healthy subjects, it was observed that movements were completed in accordance with the kinematics of the movement and that maximum movement quality was observed with less energy.
Ligamentum flavum (LF) pathologies often lead to severe myelopathy or radiculopathy characterized by reduced elasticity, obvious thickening, or worsened ossification. Elastin endows critical mechanical properties to tissues and organs such as vertebrae and ligaments. Desmosine (DES) and isodesmosine (IDES) are crosslinkers of elastin monomers called tropoelastin. These crosslinkers are potential biomarkers of chronic obstructive pulmonary disease. As a biological diagnostic tool that supplements existing symptomatic, magnetic resonance imaging scanning or radiological imaging diagnostic measures for LF hypertrophy and associated pathologies, an isotope-dilution liquid chromatography-tandem mass spectrometry method with selected reaction monitoring mode for the quantitation of DESs in human plasma, urine, cerebrospinal fluid (CSF), and yellow ligamentum was investigated. Isotopically labeled IDES-13C3,15N1 was used as an internal standard (ISTD) for DES quantitation for the first time. The samples plus ISTD were hydrolyzed with 6 N hydrochloric acid. Analytes and ISTD were extracted using a solid phase extraction cellulose cartridge column. The assays were repeatable, reproducible, and accurate with % CV ≤ 7.7, ISTD area % RSD of 7.6, and % AC ≤ (101.2 ± 3.90) of the calibrations. The ligamentum samples gave the highest average DES/IDES content (2.38 μg/mg) on a dry-weight basis. A high percentage of the CSF samples showed almost no DESs. Urine and plasma samples of patients showed no significant difference from the control (p-value = 0.0519 and 0.5707, respectively). Microscopy of the yellow ligamentum samples revealed dark or blue-colored zones of elastin fibers that retained the hematoxylin dye and highly red-colored zones of collagen after counterstaining with van Gieson solution. Thus, we successfully developed a method for DES/IDES quantitation in clinical samples.
Degenerative disc disease of the lumbosacral spine is a very common medical problem. An episode of sciatica occurs at least once in the life of 60-90% of the human population.
A phenomenon that is closely related to the process of lowering the pH of the extracellular matrix degenerating the intervertebral disc (IVD) is the precipitation of calcium salts, especially pyrophosphate dehydrate and hydroxyapatite.
In such an altered environment of the IVD, we can observe an increased influx of monocytes, macrophages, T-lymphocytes, as well as non-immunocompetent cells, which are a source of cytokines, e.g., tumor necrosis alpha (TNF-α), interleukin- (IL-1β, IL-8). The above-mentioned mediators of an inflammatory condition contribute to an increase in the expression of Brain-Derived Neurotrophic Factor (BDNF) and Glial cell Derived Neurotrophic Factor (GDNF) in mast cells and chondrocytes, as well as to the descending transport of these mediators along the nerve endings.
In the process of degeneration of the IVD as a result of repeated and even slight injuries, there is damage to the connections of the endplate of the vertebral bodies with the IVD, which results in an impairment of the penetration of nutritional substances and water into the disc. As a consequence, there is an overexpression of the brain-derived neurotrophic factor GDNF, as well as neuromodulin (GAP-43) in the mast cells and chondrocytes of the IVDs, while descending transport of these mediators along the nerve fibers is also observed.
Back pain is one of the leading causes of disability worldwide and is frequently caused by degeneration of the intervertebral discs. The discs' development, homeostasis, and degeneration are driven by a complex series of biochemical and physical extracellular matrix cues produced by and transmitted to native cells. Thus, understanding the roles of different cues is essential for designing effective cellular and regenerative therapies. Omics technologies have helped identify many new matrix cues; however, comparatively few matrix molecules have thus far been incorporated into tissue engineered models. These include collagen type I and type II, laminins, glycosaminoglycans, and their biomimetic analogues. Modern biofabrication techniques, such as 3D bioprinting, are also enabling the spatial patterning of matrix molecules and growth factors to direct regional effects. These techniques should now be applied to biochemically, physically, and structurally relevant disc models incorporating disc and stem cells to investigate the drivers of healthy cell phenotype and differentiation. Such research will inform the development of efficacious regenerative therapies and improved clinical outcomes.
Purpose:
To evaluate the biomechanics effect of modified cortical bone screw technique (MCBT) with other traditional internal fixation systems on lumbar osteoporotic wet specimen.
Methods:
Four different finite element models were established using CT data: (1) lumbar osteoporosis model without internal fixation system; (2) traditional pedicle screw technology (TT) model; (3) traditional cortical bone screw technology (CBT) model; (4) MCBT model. The changes of global displacement, intervertebral disc displacement of all models and internal fixation system Von Mises stress among the three models were compared under the same physiological load.
Results:
Compared with the other three models, the total displacement of the modified CBT screw model was the smallest, with the maximum displacement of 0.216 mm; The intervertebral disc displacement of the modified CBT screw model was the smallest, with the maximum displacement of 0.149 mm; the internal fixation system Von Mises stress of the modified CBT screw technique model was the largest compared with the other three models, The maximum Von Mises stress is 232.73 MPa.
Conclusion:
Compared to traditional pedicle screw and traditional CBT, MCBT has better mechanical stability, and it is of certain clinical application value.
Lower back pain is a leading cause of disability and is one of the reasons for the substantial socioeconomic burden. The etiology of intervertebral disc (IVD) degeneration is complicated, and its mechanism is still not completely understood. Factors such as aging, systemic inflammation, biochemical mediators, toxic environmental factors, physical injuries, and genetic factors are involved in the progression of its pathophysiology. Currently, no therapy for restoring degenerated IVD is available except pain management, reduced physical activities, and surgical intervention. Therefore, it is imperative to establish regenerative medicine-based approaches to heal and repair the injured disc, repopulate the cell types to retain water content, synthesize extracellular matrix, and strengthen the disc to restore normal spine flexion. Cellular therapy has gained attention for IVD management as an alternative therapeutic option. In this review, we present an overview of the anatomical and molecular structure and the surrounding pathophysiology of the IVD. Modern therapeutic approaches, including proteins and growth factors, cellular and gene therapy, and cell fate regulators are reviewed. Similarly, small molecules that modulate the fate of stem cells for their differentiation into chondrocytes and notochordal cell types are highlighted.
The study was conducted to find out the effect of secondary compounds extracted from Lepedium sativium seeds on the phenotypic structure of the cervical vertebrae by measuring the weight and lengths of each cervical vertebra. The study was performed in the animal house of Department of Biology, College of Education for Girls, University of Kufa, it included the use of 40 Albino rat of the Sprague Dawley strain, one months old, the average weights range (200-250g).the were divided in to 4 equal groups, the first group included the control group, which was dosed orally with distilled water only, the second group was treated with cold aqueous extract of the Lepedium sativium seeds 50 mg / kg, the third group was treated with cold aqueous extract of the Lepedium sativium seeds 100 mg / kg, the forth group was treated with cold aqueous extract of the Lepedium sativium seeds 150 mg / kg of body weight. Each group was administrated from the first day to experiment and until the sacrifice of animals, which was in two stages on 30 and 45 days for each group. The study included measuring the weights of the cervical vertebrae, as well as measuring the lengths (length, width, dimeter) of the vertebrae. The statistical analysis of the current study results was showed significant increase in weights of the cervical vertebrae in the group treated with cold eqeous extract of Lepedium sativium seed at a concentration 150 mg / kg, compared to the control group. As the Average weight increases with increasing the concentration of the extract. Also, The statistical analysis of the current study results was showed significant increase in lengths of the cervical animals treated with extract of Lepedium sativium seed at a concentration 150 mg / kg, for periods of 30 and 45 days compared to the control group.
Bu araştırma, lumbopelvik-kalça kompleksi olarak tanımlanan kasların optimizasyonunda, potansiyel güvenli egzersiz stratejisi olabilecek anti-hareket egzersiz yaklaşımının incelenmesi amacıyla geleneksel derleme türünde yazılmıştır. Yayımlanma yılı sınırlaması olmaksızın Google Akademik, PubMed ve Scopus arama tabanlarından “core exercise, safe exercise, spine and exercise” İngilizce anahtar kelimeleri kullanılarak konu ile ilişkili makaleler ele alınmıştır. Araştırma, sistematik derleme türünde yazılmadığı için tüm literatür makaleleri incelenmemiştir. Fitness sektöründe merkezi bölgeye yönelik egzersiz rutinlerine rastlamak mümkündür. Ancak tekrarlı eğilme-bükülme hareketlerinin omurgada herniasyona yol açtığı iddia edilmektedir. Yanlış uygulama kaynaklı yapısal deformitelere bağlı olarak gelişen bel ağrısı görülme oranında artış olduğu bilinmektedir. Epidemiyolojik olarak genellikle posterior zincir hattındaki instabilite veya spesifik olarak zayıf lomber omurga kaynaklı rahatsızlıklara toplumun büyük bir bölümünde rastlamak mümkündür. Diğer taraftan merkezi bölgenin gelişmesinde alternatif güvenli ve etkili egzersiz metodolojilerine ihtiyaç duyulmaktadır. Bu noktada, anti-hareket yaklaşımının omurga sağlığını ön planda tutan güvenli egzersiz stratejilerinden bir tanesi olabileceği düşünülmektedir. Bu beklentinin dayanağı, egzersiz sırasında vertebral sütunun mekanik olarak minimal iç dirence maruz kalmasıdır. Anti-hareket uygulamalarında, omurga güvenli aralık olarak isimlendirilen sınırlarda kalmakta ve dış kuvvetlere karşı moment kuvveti meydana gelmektedir. Omurganın güvenli sınırlar içerisinde tutulması ile vertebral deformitelerin veya mekanik olarak hareket kaynaklı pek çok negatif geri-bildirimin önlenebileceği düşünülmektedir. Derlemede anti-hareket uygulamalarının terminolojisinden, mekanizmalarından ve egzersiz katılımcıları açısından potansiyel progresyon stratejilerinden bahsedilmektedir. Egzersiz katılımcıları kendi sınırlılıkları veya beklentileri doğrultusunda farklı ekipman veya çoklu düzlemlerde uygulanan yeni anti-hareket kalıpları geliştirebilirler ve böylece egzersizden maksimum verim elde edebilirler.
This chapter will serve as a Q&A guide for medical students and residents regarding percutaneous vertebral augmentation, vertebroplasty and kyphoplasty, and its role in treating vertebral compression fractures. The most clinically relevant topics will be illustrated, including the difference between the two procedures, patient selection, clinical features, pre-procedural workup, indications, benefits and risks, and outcomes for these patients. References for further reading will be provided, which may help to improve understanding.
A novel whole tissue-engineered IVD consisting of a triphasic scaffold demonstrated excellent biocompatibility and mechanical properties in the porcine lumbar spine.
Low back pain represents the highest burden of musculoskeletal diseases worldwide and intervertebral disc degeneration is frequently associated with this painful condition. Even though it remains challenging to clearly recognize generators of discogenic pain, tissue regeneration has been accepted as an effective treatment option with significant potential. Tissue engineering and regenerative medicine offer a plethora of exploratory pathways for functional repair or prevention of tissue breakdown. However, the intervertebral disc has extraordinary biological and mechanical demands that must be met to assure sustained success. This concise perspective review highlights the role of the disc microenvironment, mechanical and clinical design considerations, function versus mimicry in biomaterial‐based and cell engineering strategies, and potential constraints for clinical translation of regenerative therapies for the intervertebral disc.
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We present a total tissue engineered (TE) intervertebral disc (IVD) to address IVD degradation which is a major cause of chronic neck and back pain. The TE IVD comprises an alginate hydrogel-based nucleus pulposus (NP) and hierarchically organized, concentric ring-aligned electrospun (ES) polycaprolactone (PCL)/poly (D, L-lactide-co-glycolide) (PLGA)/Collagen type I (PPC)-based annulus fibrosus (AF). The TE IVD exhibits excellent hydrophilicity to simulate highly hydrated native IVD. Long-term in vivo implantation assays demonstrate the excellent structural (shape maintenance, hydration, and integration with surrounding tissues) and functional (mechanical supporting and flexibility) performances of the TE IVD. Our study provides a novel approach for treating IVD degeneration.
Objective:
Pfirrmann disc degeneration grade is one of morphologic disc degeneration grading system and it was reliable on routine T2-weighted magnetic resonance (MR) images. The purpose of this study was to evaluate the agreement of Pfirrmann disc degeneration grade, and check the alternative technique of disc degeneration grading system.
Methods:
Fifteen volunteers (4 medical doctors related to spinal disease, 2 medical doctors not related to spinal disease, 6 nurses in spinal hospital, and 3 para-medicines) were included in this study. Three different digitalized MR images were provided all volunteers, and they checked Pfirrmann disc degeneration grade of each disc levels after careful listening to explanation. Indeed, all volunteers checked the signal intensity of disc degeneration at the points of nucleus pulposus (NP), disc membrane, ligaments, fat, and air to modify the quantitative Pfirrmann disc degeneration grade.
Results:
Total 225 grade results of Pfirrmann disc degeneration grade and 405 signal intensity results of quantitative Pfirrmann disc degeneration grade were analyzed. Average interobserver agreement was "moderate (mean±standard deviation, 0.575±0.251)" from poor to excellent. Completely agreed levels of Pfirrmann disc degeneration grade were only 4 levels (26.67%), and the disagreement levels were observed in 11 levels; two different grades in 8 levels (53.33%) and three different grades in 3 levels (20%). Quantitative Pfirrmann disc degeneration showed relatively cluster distribution with the interobserver deviations of 0.41-1.56 at the ratio of NP and disc membrane, and it showed relatively good cluster and distribution indicating that the proposed grading system has good discrimination ability.
Conclusion:
Pfirrmann disc degeneration grade showed the limitation of different interobserver results, but this limitation could be overcome by using quantitative techniques of MR signal intensity. Further evaluation is needed to access its advantage and reliabilities.
Articular cartilage (AC) covers the diarthrodial joints and is responsible for the mechanical distribution of loads across the joints. The majority of its structure and function is controlled by chondrocytes that regulate Extracellular Matrix (ECM) turnover and maintain tissue homeostasis. Imbalance in their function leads to degenerative diseases like Osteoarthritis (OA). OA is characterized by cartilage degradation, osteophyte formation and stiffening of joints. Cartilage degeneration is a consequence of chondrocyte hypertrophy along with the expression of proteolytic enzymes. Matrix Metalloproteinases (MMPs) and A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) are an example of these enzymes that degrade the ECM. Signaling cascades involved in limb patterning and cartilage repair play a role in OA progression. However, the regulation of these remains to be elucidated. Further the role of stem cells and mature chondrocytes in OA progression is unclear. The progress in cell based therapies that utilize Mesenchymal Stem Cell (MSC) infusion for cartilage repair may lead to new therapeutics in the long term. However, many questions are unanswered such as the efficacy of MSCs usage in therapy. This review focuses on the role of chondrocytes in cartilage formation and the progression of OA. Moreover, it summarizes possible alternative therapeutic approaches using MSC infusion for cartilage restoration.
Tissue engineering offers high hopes for the treatment of intervertebral disc (IVD) degeneration. Whereas scaffolds of the disc nucleus and annulus have been extensively studied, a truly biomimetic and mechanically functional biphasic scaffold using naturally occurring extracellular matrix is yet to be developed. Here, a biphasic scaffold was fabricated with collagen and glycosaminoglycans (GAGs), two of the most abundant extracellular matrix components in the IVD. Following fabrication, the scaffold was characterized and benchmarked against native disc. The biphasic scaffold was composed of a collagen-GAG co-precipitate making up the nucleus pulposus-like core, and this was encapsulated in multiple lamellae of photochemically crosslinked collagen membranes comprising the annulus fibrosus-like lamellae. On mechanical testing, the height of our engineered disc recovered by ~82-89% in an annulus-independent manner, when compared with the 99% recovery exhibited by native disc. The annulus-independent nature of disc height recovery suggests that the fluid replacement function of the engineered nucleus pulposus core might mimic this hitherto unique feature of native disc. Biphasic scaffolds comprised of 10 annulus fibrosus-like lamellae had the best overall mechanical performance among the various designs owing to their similarity to native disc in most aspects, including elastic compliance during creep and recovery, and viscous compliance during recovery. However, the dynamic mechanical performance (including dynamic stiffness and damping factor) of all the biphasic scaffolds was similar to that of the native discs. This study contributes to the rationalized design and development of a biomimetic and mechanically viable biphasic scaffold for IVD tissue engineering.
Annulus fibrosus (AF) tissue engineering has recently received increasing attention as a treatment for intervertebral disc (IVD) degeneration; however, such engineering remains challenging because of the remarkable complexity of AF tissue. In order to engineer a functional AF replacement, the fabrication of cell-scaffold constructs that mimic the cellular, biochemical and structural features of native AF tissue is critical. In this study, we fabricated aligned fibrous polyurethane scaffolds using an electrospinning technique and used them for culturing AF-derived stem/progenitor cells (AFSCs). Random fibrous scaffolds, also prepared via electrospinning, were used as a control. We compared the morphology, proliferation, gene expression and matrix production of AFSCs on aligned scaffolds and random scaffolds. There was no apparent difference in the attachment or proliferation of cells cultured on aligned scaffolds and random scaffolds. However, compared to cells on random scaffolds, the AFSCs on aligned scaffolds were more elongated and better aligned, and they exhibited higher gene expression and matrix production of collagen-I and aggrecan. The gene expression and protein production of collagen-II did not appear to differ between the two groups. Together, these findings indicate that aligned fibrous scaffolds may provide a favourable microenvironment for the differentiation of AFSCs into cells similar to outer AF cells, which predominantly produce collagen-I matrix.
Adults suffering from lower back pain often find the cause of pain is degenerative disc disease. While non-surgical treatment is preferred, spinal fusion and total disc replacement remain surgical options for the patient. Total disc replacement is an emerging and improving treatment for degenerative discs. This paper provides a review of lumbar disc replacement for treatment of lower back pain. The mechanics and configuration of the natural disc are first discussed, followed by an introduction of treatment methods that attempt to mimic these mechanics. Total disc replacement types, materials, and failure mechanisms are discussed. Failure mechanisms primarily involve biochemical reactions to implant wear, as well as mechanical incompatibility of the device with natural spine motion. Failure mechanisms include: osteolysis, plastic deformation of polymer components, pitting, fretting, and adjacent level facet and disc degeneration.
The biochemical and biophysical properties of the extracellular matrix (ECM) dictate tissue-specific cell behaviour. The molecules that are associated with the ECM of each tissue, including collagens, proteoglycans, laminins and fibronectin, and the manner in which they are assembled determine the structure and the organization of the resultant ECM. The product is a specific ECM signature that is comprised of unique compositional and topographical features that both reflect and facilitate the functional requirements of the tissue.
End plates serve as the interface between rigid vertebral bodies and pliant intervertebral disks. Because the lumbar spine carries significant forces and disks don't have a dedicated blood supply, end plates must balance conflicting requirements of being strong to prevent vertebral fracture and porous to facilitate transport between disk cells and vertebral capillaries. Consequently, end plates are particularly susceptible to damage, which can increase communication between proinflammatory disk constituents and vascularized vertebral bone marrow. Damaged end plate regions can be sites of reactive bone marrow lesions that include proliferating nerves, which are susceptible to chemical sensitization and mechanical stimulation. Although several lines of evidence indicate that innervated end plate damage can be a source of chronic low back pain, its role in patients is likely underappreciated because innervated damage is poorly visualized with diagnostic imaging. This literature review summarizes end plate biophysical function and aspects of pathologic degeneration that can lead to vertebrogenic pain. Areas of future research are identified in the context of unmet clinical needs for patients with chronic low back pain.
Over the past few decades, remarkable advancements in the understanding of the origin of low-back pain and lumbar spinal disorders have been achieved. Spinal fusion is generally considered the “gold standard” in the treatment of low-back pain; however, fusion is also associated with accelerated degeneration of adjacent levels. Spinal arthroplasty and dynamic stabilization technologies, as well as the continuous improvement in diagnosis and surgical interventions, have opened a new era of treatment options. Recent advancements in nonfusion technologies such as motion-preservation devices and posterior dynamic stabilization may change the gold standard. These devices are designed with the intent to provide stabilization and eliminate pain while preserving motion of the functional spinal unit. The adaption of nonfusion technologies by the surgical community and payers for the treatment of degenerative spinal conditions will depend on the long-term clinical outcome of controlled randomized clinical studies. Although the development of nonfusion technology has just started and the adoption is very slow, it may be considered a viable option for motion preservation in coming years. This review article provides technical and surgical views from the past and from the present, as well as a glance at the future endeavors and challenges in instrumentation development for lumbar spinal disorders.
© 2011 SAS - The International Society for the Advancement of Spine Surgery. Published by Elsevier Inc. All rights reserved.
Background & objectives:
Various materials have been used as scaffolds to suit different demands in tissue engineering. One of the most important criteria is that the scaffold must be biocompatible. This study was carried out to investigate the potential of HA or TCP/HA scaffold seeded with osteogenic induced sheep marrow cells (SMCs) for bone tissue engineering.
Methods:
HA-SMC and TCP/HA-SMC constructs were induced in the osteogenic medium for three weeks prior to implantation in nude mice. The HA-SMC and TCP/HA-SMC constructs were implanted subcutaneously on the dorsum of nude mice on each side of the midline. These constructs were harvested after 8 wk of implantation. Constructs before and after implantation were analyzed through histological staining, scanning electron microscope (SEM) and gene expression analysis.
Results:
The HA-SMC constructs demonstrated minimal bone formation. TCP/HA-SMC construct showed bone formation eight weeks after implantation. The bone formation started on the surface of the ceramic and proceeded to the centre of the pores. H&E and Alizarin Red staining demonstrated new bone tissue. Gene expression of collagen type 1 increased significantly for both constructs, but more superior for TCP/HA-SMC. SEM results showed the formation of thick collagen fibers encapsulating TCP/HA-SMC more than HA-SMC. Cells attached to both constructs surface proliferated and secreted collagen fibers.
Interpretation & conclusions:
The findings suggest that TCP/HA-SMC constructs with better osteogenic potential compared to HA-SMC constructs can be a potential candidate for the formation of tissue engineered bone.
Lumbar discectomy is the surgical procedure most frequently performed for patients suffering from low back pain and sciatica. Disc herniation as a consequence of degenerative or traumatic processes is commonly encountered as the underlying cause for the painful condition. While discectomy provides favourable outcome in a majority of cases, there are conditions where unmet requirements exist in terms of treatment, such as large disc protrusions with minimal disc degeneration; in these cases, the high rate of recurrent disc herniation after discectomy is a prevalent problem. An effective biological annular repair could improve the surgical outcome in patients with contained disc herniations but otherwise minor degenerative changes. An attractive approach is a tissue-engineered implant that will enable/stimulate the repair of the ruptured annulus. The strategy is to develop three-dimensional scaffolds and activate them by seeding cells or by incorporating molecular signals that enable new matrix synthesis at the defect site, while the biomaterial provides immediate closure of the defect and maintains the mechanical properties of the disc. This review is structured into (1) introduction, (2) clinical problems, current treatment options and needs, (3) biomechanical demands, (4) cellular and extracellular components, (5) biomaterials for delivery, scaffolding and support, (6) pre-clinical models for evaluation of newly developed cell- and material-based therapies, and (7) conclusions. This article highlights that an interdisciplinary approach is necessary for successful development of new clinical methods for annulus fibrosus repair. This will benefit from a close collaboration between research groups with expertise in all areas addressed in this review.
Cervical radiculopathy is defined as a syndrome of pain and/or sensorimotor deficits due to compression of a cervical nerve root. Understanding of this disease is vital for rapid diagnosis and treatment of patients with this condition, facilitating their recovery and return to regular activity.
This review is designed to clarify (1) the pathophysiology that leads to nerve root compression; (2) the diagnosis of the disease guided by history, physical exam, imaging, and electrophysiology; and (3) operative and non-operative options for treatment and how these should be applied.
The PubMed database was searched for relevant articles and these articles were reviewed by independent authors. The conclusions are presented in this manuscript.
Facet joint spondylosis and herniation of the intervertebral disc are the most common causes of nerve root compression. The clinical consequence of radiculopathy is arm pain or paresthesias in the dermatomal distribution of the affected nerve and may or may not be associated with neck pain and motor weakness. Patient history and clinical examination are important for diagnosis. Further imaging modalities, such as x-ray, computed tomography, magnetic resonance imaging, and electrophysiologic testing, are of importance. Most patients will significantly improve from non-surgical active and passive therapies. Indicated for surgery are patients with clinically significant motor deficits, debilitating pain that is resistant to conservative modalities and/or time, or instability in the setting of disabling radiculopathy. Surgical treatment options include anterior cervical decompression with fusion and posterior cervical laminoforaminotomy.
Understanding the pathophysiology, diagnosis, treatment indications, and treatment techniques is essential for rapid diagnosis and care of patients with cervical radiculopathy.
Articular cartilage is the highly specialized connective tissue of diarthrodial joints. Its principal function is to provide a smooth, lubricated surface for articulation and to facilitate the transmission of loads with a low frictional coefficient (Figure 1). Articular cartilage is devoid of blood vessels, lymphatics, and nerves and is subject to a harsh biomechanical environment. Most important, articular cartilage has a limited capacity for intrinsic healing and repair. In this regard, the preservation and health of articular cartilage are paramount to joint health.
Figure 1.
Gross photograph of healthy articular cartilage in an adult human knee.
Injury to articular cartilage is recognized as a cause of significant musculoskeletal morbidity. The unique and complex structure of articular cartilage makes treatment and repair or restoration of the defects challenging for the patient, the surgeon, and the physical therapist. The preservation of articular cartilage is highly dependent on maintaining its organized architecture.
The prevalence of intervertebral disc herniation (IDH) of the thoracic spine is rare compared to the cervical or lumbar spine. In particular, IDH of the upper thoracic spine is extremely rare. We report the case of T1-2 IDH and its treatment, with a literature review. A 37-year-old male patient visited our hospital due to radiating pain at the left upper extremity and weakness of grip power. In cervical spine magnetic resonance images, T1-2 disc space showed herniated disc material and compressed T1 root was identified. Laminoforaminotomy was performed with a posterior approach. The radiating pain and weakness of grip power improved immediately after the surgery. Of patients who show radiating pain or numbness at the medial aspect of forearm, or weakness of intrinsic muscle of hand, can be suspected to have T1 radiculopathy. A detailed physical examination and a radiologic evaluation including this area should be required for the T1 radiculopathy.
The interpretation of spinal images fixed with metallic hardware forms an increasing bulk of daily practice in a busy imaging department. Radiologists are required to be familiar with the instrumentation and operative options used in spinal fixation and fusion procedures, especially in his or her institute. This is critical in evaluating the position of implants and potential complications associated with the operative approaches and spinal fixation devices used. Thus, the radiologist can play an important role in patient care and outcome. This review outlines the advantages and disadvantages of commonly used imaging methods and reports on the best yield for each modality and how to overcome the problematic issues associated with the presence of metallic hardware during imaging. Baseline radiographs are essential as they are the baseline point for evaluation of future studies should patients develop symptoms suggesting possible complications. They may justify further imaging workup with computed tomography, magnetic resonance and/or nuclear medicine studies as the evaluation of a patient with a spinal implant involves a multi-modality approach. This review describes imaging features of potential complications associated with spinal fusion surgery as well as the instrumentation used. This basic knowledge aims to help radiologists approach everyday practice in clinical imaging.
Cervical disc herniation often results in neck and arm pain in patients as a result of direct impingement of nerve roots and associated inflammatory processes. The clinical presentation usually corresponds with the side of herniation and ipsilateral symptoms predominate the clinical picture.
A 35-year-old Caucasian man presented to our facility with neck pain and left-sided upper and lower extremity pain. A magnetic resonance imaging scan revealed a right paramedian herniated disc at the C5 to C6 level. All other cervical levels were normal without central canal stenosis or neural foraminal stenosis. Results from magnetic reasonance imaging scans of the brain and lumbar spine were negative. An anterior cervical discectomy was performed at the C5 to C6 level, and an inter-body graft and plate were placed. Our patient had complete resolution of his neck and left arm pain.
Anterior discectomy and fusion of the cervical spine resulted in complete resolution of our patient's neck and left arm symptoms and improvement of his contralateral left leg pain. Cervical disc herniation may present with contralateral symptoms that are different from the current perception of this disease.
Low back pain as a result of degenerative disc disease imparts a large socioeconomic impact on the health care system. Traditional concepts for treatment of lumbar disc degeneration have aimed at symptomatic relief by limiting motion in the lumbar spine, but novel treatment strategies involving stem cells, growth factors, and gene therapy have the theoretical potential to prevent, slow, or even reverse disc degeneration. Understanding the pathophysiological basis of disc degeneration is essential for the development of treatment strategies that target the underlying mechanisms of disc degeneration rather than the downstream symptom of pain. Such strategies ideally aim to induce disc regeneration or to replace the degenerated disc. However, at present, treatment options for degenerative disc disease remain suboptimal, and development and outcomes of novel treatment options currently have to be considered unpredictable.
Annulus fibrosus (AF) tissue engineering is gathering increasing interest for the development of strategies to reduce recurrent disc herniation (DH) rate and to increase the effectiveness of intervertebral disc regeneration strategies. This study evaluates the use of a bioactive microfibrous poly(L-lactide) scaffold releasing Transforming Growth Factor (TGF)-β1 (PLLA/TGF) for the repair and regeneration of damaged AF.
The scaffold was synthesized by electrospinning, with a direct incorporation of TGF-β1 into the polymeric solution, and characterized in terms of morphology and drug release profile. Biological evaluation was performed with bovine AF cells (AFCs) that were cultured on the scaffold up to 3 weeks to quantitatively assess glycosaminoglycans and total collagen production, using bare electrospun PLLA as a control. Histological evaluation was performed to determine the thickness of the deposited neo-ECM.
Results demonstrated that AFCs cultured on PLLA/TGF deposited a significantly greater amount of glycosaminoglycans and total collagen than the control, with higher neo-ECM thickness.
PLLA/TGF scaffold induced an anabolic stimulus on AFCs, mimicking the ECM three-dimensional environment of AF tissue. This bioactive scaffold showed encouraging results that allow envisaging an application for AF tissue engineering strategies and AF repair after discectomy for the prevention of recurrent DH.
Retrospective chart review.
To evaluate the incidence of potential total disc replacement (TDR) candidates among cervical and lumbar fusion patient populations using strict Food and Drug Administration (FDA) criteria and with relative exclusion criteria removed.
Recent studies suggest that the potential percentage of patients that are candidates for TDR ranges from 0-5% in lumbar fusions and 43% in cervical fusions.
We performed a retrospective chart review of 280 consecutive patients who had lumbar (n = 174) and cervical (n = 106) fusion or TDR performed by one of four independent adult orthopaedic spine surgeons. Charts were screened for investigational device exemption (IDE) inclusion/exclusion criteria and later reanalyzed excluding relative exclusion criteria, such as history of chronic medical illness, twolevel disease (cervical cases), and history of prior fusion surgery in the anatomic region.
Of the 174 lumbar surgeries, 10 were TDR with Prodisc-L and 164 were lumbar fusions. The most common TDR exclusion criteria were lytic spondylolisthesis or spinal stenosis (47.7% of patients) and more than 2 level degenerative disc disease (37.9%). 14.9% had no IDE exclusion criteria and would be considered candidates for TDR. After excluding the relative lumbar exclusion criteria, this percentage increased to 25.8%. Of the 106 cervical cases, 3 had a TDR with Prodisc-C and 103 had a cervical fusion. Twenty eight percent had no IDE exclusion criteria and would be considered candidates for cervical TDR.
A larger percentage of cervical fusion candidates are potential candidates for TDR (28%) than lumbar fusion candidates (14.9%) based on the strict IDE criteria.
Biomaterials science has achieved significant advancements for the replacement, repair and regeneration of intervertebral disc tissues. However, the translation of this research to the clinic presents hurdles. The goal of this paper is to identify strategies to recapitulate the intrinsic complexities of the intervertebral disc, to highlight the unresolved issues in basic knowledge hindering the clinical translation, and finally to report on the emerging technologies in the biomaterials field. On this basis, we identify promising research directions, with the hope of stimulating further debate and advances for resolving clinical problems such as cervical and low back pain using biomaterial-based approaches.
Statement of significance:
Although not life-threatening, intervertebral disc disorders have enormous impact on life quality and disability. Disc function within the human body is mainly mechanical, and therefore the use of biomaterials to rescue disc function and alleviate pain is logical. Despite intensive research, the clinical translation of biomaterial-based therapies is hampered by the intrinsic complexity of this organ. After decades of development, artificial discs or tissue replacements are still niche applications given their issues of integration and displacement with detrimental consequences. The struggles of biological therapies and tissue engineering are therefore understandable. However, recent advances in biomaterial science give new hope. In this paper we identify the most promising new directions for intervertebral disc biomaterials.
Mimicking the three-dimensional (3D) biological structure of native tissues and organs has remained a challenge for tissue engineering. The current use of hydrogels for intervertebral disc (IVD) repair is not ideal for insufficient mechanical properties. To overcome this limitation, we combine the excellent mechanical performance of poly(lactic acid) (PLA) with the biocompatibility and bioprintability of gellan gum-poly (ethylene glycol) diacrylate (GG-PEGDA) double network hydrogel to meet the necessary requirement of IVD regeneration. The cell-laden constructs were fabricated using 3D bioprinting technology. Mechanical and degradation properties of the dual printed scaffolds can be regulated by controlling the infill patterns and density of the PLA frameworks. Bone marrow stromal cells co-printed into the PLA/GG-PEGDA scaffolds remained high viability and showed excellent spreading within the hydrogels. Considering positive biocompatibility accompanied with suitable mechanical properties, this hybrid scaffolds have the potential to assist IVD regeneration.
Significance
In this study we have developed a fabrication procedure for a silk-based bioartificial disc adopting a directional freezing technique. The fabricated biodisc mimicked the internal intricacy of the native disc as evaluated by electron microscopy. The mechanical properties of these biodiscs were similar to those of the native ones. The fabricated biodiscs supported primary annulus fibrosus or human mesenchymal stem cell proliferation, differentiation, and deposition of a sufficient amount of specific ECM. A small unit of the construct was implanted subcutaneously to show its negligible immune response. The success here means that the silk-based bioartificial disc can be a promising strategy for future direction toward disc replacement therapy.
Defects in the annulus fibrosus (AF) of intervertebral discs allow nucleus pulposus tissue to herniate causing painful disability. Microdiscectomy procedures remove herniated tissue fragments but unrepaired defects remain allowing reherniation or progressive degeneration. Cell therapies show promise to enhance repair but methods are undeveloped and carriers are required to prevent cell leakage. To address this challenge, this study developed and evaluated genipin-crosslinked fibrin (FibGen) as an adhesive cell carrier optimized for AF repair that can deliver cells, match AF material properties and have low risk of extrusion during loading. Part 1 determined feasibility of bovine AF cells encapsulated in high concentration FibGen (F140G6: 140mg/ml fibrinogen; 6mg/ml genipin) for 7 weeks could maintain high viability, but had little proliferation or matrix deposition. Part 2 screened tissue mechanics and in situ failure testing of nine FibGen formulations (fibrin: 35-140mg/ml; genipin: 1-6 mg/ml). F140G6 formulation matched AF shear and compressive properties and significantly improved failure strength in situ. Formulations with reduced genipin also exhibited satisfactory material properties and failure behaviors warranting further biological screening. Part 3 screened AF cells encapsulated in four FibGen formulations for one-week and found reduced genipin concentrations increased cell viability and glycosaminoglycan production. F70G1 (70mg/ml fibrinogen; 1mg/ml genipin) demonstrated balanced biological and biomechanical performance warranting further testing. We conclude that FibGen has potential to serve as an adhesive cell carrier to repair AF defects with formulations that can be tuned to enhance biomechanical and biological performance; future studies are required to develop strategies to enhance matrix production.
Intervertebral disc (IVD) degeneration is related to both structural damage and aging. Annulus fibrosus (AF) defects such as annular tears, herniation and discectomy require novel strategies to functionally repair AF tissue. An ideal construct will repair the AF by providing physical and biological support and by facilitating regeneration. The present strategy proposes a gellan gum-based construct reinforced with cellulose nanocrystals (nCell) as a biological self-gelling AF substitute. Nanocomposite hydrogels were fabricated and characterized for their swelling capacity and stability and physico-chemical properties. Rheological evaluation on the nanocomposites demonstrated the GGMA reinforcement with nCell and thus matrix entanglements with higher stiffness upon ionic crosslinking. Compressive mechanical tests demonstrate values close to those of the human AF tissue. Furthermore, cell culture studies by means of gel loading with bovine AF cells indicated that the construct promoted cell viability and a physiologically relevant morphology for up to fourteen days in vitro.
Intervertebral disc degeneration is recognized to be the leading cause for chronic low-back pain. Injectable hydrogel is one of the great interests for tissue engineering and cell encapsulation specially for intervertebral (IVD) affecting rate of regeneration success, in this study we assessed viscoelastic properties of a Chitosan-β glycerophosphate-hyaluronic acid, Chondroitin-6-sulfate, type 2 of Collagen, gelatin, fibroin silk (Ch-β-GP-HA-CS-Col-Ge-FS) hydrogel which was named as NP hydrogel that is natural extracellular matrix of IVD.
Chitosan-based hydrogel was made in the ratio of 1.5%: 7%: 1%:1%:1%–1.5%–1% (Ch: β-GP: HA-CS-Col-Ge-FS). Gelation time and other rheological properties were studied using amplitude sweep and frequency sweep tests. Also, the cytotoxicity of the hydrogel invitro assessed by MTT and trypan blue tests. Morphology of the hydrogel and attachment of NP cells were evaluated by SEM.
Our result showed that NP hydrogel in 4 °C is an injectable transparent solution. It started gelation in 37 °C after about 30 min. Gelation temperature of NP hydrogel was 37 °C. Storage modulus (G′) of this hydrogel at 37 °C was almost constant over a wide range of strain. MTT and trypan blue tests showed hydrogel was cytocompatible. The obtained results suggest that this hydrogel would be a natural and cytocompatible choice as an injectable scaffold for using in vivo study of IVD regeneration.
Hydrogel is a suitable scaffold for the nucleus pulposus (NP) regeneration. However, its unmatched mechanical properties lead to implant failure in late-stage disc degeneration because of structural failure and implant extrusion after long-term compression. In this study, we evaluated an interpenetrating network (IPN)-strengthened and toughened hydrogel for NP regeneration, using dextran and gelatin as the primary network while poly (ethylene glycol) as the secondary network. The aim of this study was to realize the NP regeneration using the hydrogel. To achieve this, we optimized its properties by adjusting the mass ratios of the secondary/primary networks and determining the best preparation conditions for NP regeneration in a series of biomechanical, cytocompatibility, tissue engineering, and in vivo study. We found the optimal formulation of the IPN hydrogel, at a secondary/primary network ratio of 1:4, exhibited high toughness (the compressive strain reached 86%). The encapsulated NP cells showed increasing proliferation, cell clustering and matrix deposition. Furthermore, the hydrogel could support long-term cell retention and survival in the rat IVDs. It facilitated rehydration and regeneration of porcine degenerative NPs. In conclusion, this study demonstrates the tough IPN hydrogel could be a promising candidate for functional disc regeneration in future.
The intervertebral disc (IVD) is composed of nucleus pulposus (NP) surrounded by multilamellated annulus fibrosus (AF), and is located between the vertebral bodies. Current treatments for chronic neck or low back pain do not completely restore the functionality of degenerated IVDs. Thus developing biological disc replacements is an approach of great interest. Given the complex structure of the IVD, tissue engine