Fibrocartilage
Triangular Fibrocartilage
Tendons
Wrist Joint
Ligaments, Articular
Cartilage
Cartilage, Articular
Ligaments
Aggrecans
Hyaline Cartilage
Patellar Ligament
Keratan Sulfate
Tissue Engineering
Temporomandibular Joint
Calcification, Physiologic
Periosteum
Temporomandibular Joint Disc
Compressive Strength
Collagen Type II
Glycosaminoglycans
Chondrocalcinosis
Epiphyses
Collagen
Mandibular Condyle
Biomechanical Phenomena
Versicans
Tissue Scaffolds
Arthrography
Anterior Cruciate Ligament
Joint Diseases
Chondrogenesis
Dermatan Sulfate
Chondroitin Sulfates
Extracellular Matrix Proteins
Stress, Mechanical
Immunohistochemistry
Bone and Bones
Lectins, C-Type
Mesenchymal Stromal Cells
Osteoarthritis
Extracellular Matrix
Rabbits
Sheep
Cattle
Microscopy, Electron, Scanning
Relaxin's induction of metalloproteinases is associated with the loss of collagen and glycosaminoglycans in synovial joint fibrocartilaginous explants. (1/83)
Diseases of specific fibrocartilaginous joints are especially common in women of reproductive age, suggesting that female hormones contribute to their etiopathogenesis. Previously, we showed that relaxin dose-dependently induces matrix metalloproteinase (MMP) expression in isolated joint fibrocartilaginous cells. Here we determined the effects of relaxin with or without beta-estradiol on the modulation of MMPs in joint fibrocartilaginous explants, and assessed the contribution of these proteinases to the loss of collagen and glycosaminoglycan (GAG) in this tissue. Fibrocartilaginous discs from temporomandibular joints of female rabbits were cultured in medium alone or in medium containing relaxin (0.1 ng/ml) or beta-estradiol (20 ng/ml) or relaxin plus beta-estradiol. Additional experiments were done in the presence of the MMP inhibitor GM6001 or its control analog. After 48 hours of culture, the medium was assayed for MMPs and the discs were analyzed for collagen and GAG concentrations. Relaxin and beta-estradiol plus relaxin induced the MMPs collagenase-1 and stromelysin-1 in fibrocartilaginous explants--a finding similar to that which we observed in pubic symphysis fibrocartilage, but not in articular cartilage explants. The induction of these proteinases by relaxin or beta-estradiol plus relaxin was accompanied by a loss of GAGs and collagen in joint fibrocartilage. None of the hormone treatments altered the synthesis of GAGs, suggesting that the loss of this matrix molecule probably resulted from increased matrix degradation. Indeed, fibrocartilaginous explants cultured in the presence of GM6001 showed an inhibition of relaxin-induced and beta-estradiol plus relaxin-induced collagenase and stromelysin activities to control baseline levels that were accompanied by the maintenance of collagen or GAG content at control levels. These findings show for the first time that relaxin has degradative effects on non-reproductive synovial joint fibrocartilaginous tissue and provide evidence for a link between relaxin, MMPs, and matrix degradation. (+info)Jacob's disease associated with temporomandibular joint dysfunction: a case report. (2/83)
Jacob's disease is regarded a rare condition in which a joint formation is established between an enlarged mandibular coronoid process and the inner aspect of the zygomatic body. Chronic temporomandibular joint (TMJ) disk displacement has been proposed as etiological factor of coronoid process enlargement. We present a 23-year-old woman with long-standing TMJ dysfunction and restricted interincisal opening, who developed a progressive zygomatic asymmetry. The patient underwent treatment by intraoral coronoidectomy and homolateral TMJ arthroscopy in the same surgery. The histopathological diagnosis of the coronoid sample was cartilage-capped exostoses with presence of articular fibrous cartilage. Although the low prevalence of this entity, it should be considered as a possible diagnosis in patients with progressive limitation of mouth opening, although a TMJ syndrome may be present as a cause of this entity. (+info)Growth factor expression in degenerated intervertebral disc tissue. An immunohistochemical analysis of transforming growth factor beta, fibroblast growth factor and platelet-derived growth factor. (3/83)
Degenerated intervertebral disc has lost its normal architecture, and there are changes both in the nuclear and annular parts of the disc. Changes in cell shape, especially in the annulus fibrosus, have been reported. During degeneration the cells become more rounded, chondrocyte-like, whereas in the normal condition annular cells are more spindle shaped. These chondrocyte-like cells, often forming clusters, affect extracellular matrix turnover. In previous studies transforming growth factor beta (TGFbeta) -1 and -2, basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) have been highlighted in herniated intervertebral disc tissue. In the present study the same growth factors are analysed immunohistochemically in degenerated intervertebral disc tissue. Disc material was obtained from 16 discs operated for painful degenerative disc disease. Discs were classified according to the Dallas Discogram Description. Different disc regions were analysed in parallel. As normal control disc tissue material from eight organ donors was used. Polyclonal antibodies against different growth factors and TGFbeta receptor type II were used, and the immunoreaction was detected by the avidin biotin complex method. All studied degenerated discs showed immunoreactivity for TGFbeta receptor type II and bFGF. Fifteen of 16 discs were immunopositive for TGFbeta-1 and -2, respectively, and none showed immunoreaction for PDGF. Immunopositivity was located in blood vessels and in disc cells. In the nucleus pulposus the immunoreaction was located almost exclusively in chondrocyte-like disc cells, whereas in the annular region this reaction was either in chondrocyte-like disc cells, often forming clusters, or in fibroblast-like disc cells. Chondrocyte-like disc cells were especially prevalent in the posterior disrupted area. In the anterior area of the annulus fibrosus the distribution was more even between these two cell types. bFGF was expressed in the anterior annulus fibrosus more often in chondrocyte-like disc cells than in fibroblast-like disc cells. Control discs showed cellular immunopositivity for only TGFbeta-1 and -2 and TGFbeta receptor type II . We suggest that growth factors create a cascade in intervertebral disc tissue, where they act and participate in cellular remodelling from the normal resting stage via disc degeneration to disc herniation. (+info)The potential value of blood biomarkers of intervertebral disk metabolism in the follow-up of patients with sciatica. (4/83)
STUDY DESIGN: This is a prospective study with a follow-up period of 4 years. OBJECTIVES: The study aimed to evaluate the possible clinical utility of three biomarkers [i.e., keratan sulfate (KS), hyaluronan, and cartilage oligomeric matrix protein] measured in peripheral blood in severe acute sciatica at intake and follow-up. SUMMARY OF BACKGROUND: Our previous study and others have pointed out the interest of different laboratory tests in the acute phase of sciatica. Several blood biomarkers have been reported useful in the long-term follow-up of patients with osteoarthritis. We have found no information about the potential interest of these tests in spinal disorders. METHODS: Patients were admitted to the hospital for intensive conservative management of acute sciatica (n=82). A subgroup of patients (n=33) was selected based on the duration of symptoms at visit 1, and included those with the shortest (n=24) as well as those with the longest (n=9) duration of sciatica. Blood samples were drawn, centrifuged, and the plasma frozen. Antigenic KS, hyaluronan, and cartilage oligomeric matrix protein were measured by ELISA. Patients were re-evaluated at an average of 4.3 years (range: 2.1-6.8 years). RESULTS: Thirty-three subjects with an average age of 49.2+/-10.2 years participated. At intake, levels of the three biomarkers evaluated were within the range of normal values. No significant differences were found between the results of patients with a short history of sciatica (< or =3 weeks) and those with a long duration of symptoms (>20 weeks). At follow-up, a significant increase (P<0.05) in all three biomarkers was found. CONCLUSIONS: A single measurement of these three biomarker molecules does not seem to have any diagnostic or therapeutic relevance in patients with acute radicular compression. The significance of the increase in all three biomarkers after a mean follow-up of 4.3 years is unclear; it might reflect metabolic processes involved in degenerative spinal disorders. Even though we found no correlation with clinical outcome, we believe that more research is needed. (+info)The pathogenesis and clinical significance of a high-intensity zone (HIZ) of lumbar intervertebral disc on MR imaging in the patient with discogenic low back pain. (5/83)
Recently, the presence of a high-intensity zone (HIZ) within the posterior annulus seen on T2-weighted MRI has aroused great interest and even controversy among many investigators, particularly on whether the HIZ was closely associated with a concordant pain response on awake discography. The study attempted to interpret the correlation between the presence of the HIZ on MRI and awake discography, as well as its characteristic pathology. Fifty two patients with low back pain without disc herniation underwent MRI and discography successively. Each disc with HIZ was correlated for an association between the presence of a HIZ and the grading of annular disruption and a concordant pain response. Eleven specimens of lumbar intervertebral discs which contain HIZ in the posterior annulus from 11 patients with discogenic low back pain were harvested for histologic examination to interpret the histologic basis of a nociceptive response during posterior lumbar interbody fusion (PLIF). The study found that in all of 142 discograms in 52 patients, 17 presented HIZ. All 17 discs with HIZ showed painful reproduction and abnormal morphology with annular tears extending either well into or through the outer third of the annulus fibrosus. The consecutive sagittal slices through the HIZ lesion showed that a notable histologic feature of the formation of vascularized granulation tissue in the outer region of the annulus fibrosus. The current study suggests that the HIZ of the lumbar disc on MRI in the patient with low back pain could be considered as a reliable marker of painful outer anular disruption. (+info)Intervertebral disc degeneration in relation to the COL9A3 and the IL-1ss gene polymorphisms. (6/83)
Disc degeneration is a complex condition in which environmental factors and multiple genes are expected to act together to determine the degenerative phenotype. Recently associations of COL9A2 (Trp2 allele) and COL9A3 (Trp3 allele) polymorphisms with lumbar disc disease characterized by sciatica have been reported. However, it is not known whether the Trp2 or Trp3 alleles contribute to disc degeneration (DD). In this study, the association between the collagen genes polymorphisms and lumbar DD was investigated. Furthermore, the influence of the IL-1beta(C(3954)-T) polymorphism on the association of collagen genes polymorphisms with DD was examined. Lumbar intervertebral discs of 135 middle-aged occupationally active men were evaluated with magnetic resonance imaging, using decreased signal intensity of the nucleus pulposus, disc bulges, and decreased disc height as signs of degeneration. Blood samples were analysed for the presence of COL9A3 and COL9A2 tryptophan alleles (Trp3 and Trp2 alleles). The COL11A2, COL2A1 and IL-1beta(C(3954)-T) polymorphisms were also analysed. Multivariate logistic regression analysis allowing for occupation and body mass index showed that the carriage of the Trp3 allele in the absence of the IL-1betaT(3954) allele increased the risk of dark nucleus pulposus (OR 7.0, 95% CI 1.3-38.8) and joint occurrence of degenerative changes (OR 8.0, 95% CI 1.4-44.7). There was no effect of the Trp3 allele on DD in the presence of the IL-1betaT(3954) allele. The carriers of the COL11A2 minor allele had an increased risk of disc bulges (OR 2.1, 95% CI 1.0-4.2) as compared with non-carriers. The results suggest that the effect of the COL9A3 gene polymorphism on DD might be modified by the IL-1beta gene polymorphism. (+info)Intradiscal pressure measurements in normal discs, compressed discs and compressed discs treated with axial posterior disc distraction: an experimental study on the rabbit lumbar spine model. (7/83)
Intervertebral disc (IVD) pressure measurement is an appropriate method for characterizing spinal loading conditions. However, there is no human or animal model that provides sufficient IVD pressure data. The aim of our study was to establish physiological pressure values in the rabbit lumbar spine and to determine whether temporary external disc compression and distraction were associated with pressure changes. Measurements were done using a microstructure-based fibreoptic sensor. Data were collected in five control rabbits (N, measurement lying prone at segment L3/4 at day 28), five rabbits with 28 days of axial compression (C, measurement at day 28) and three rabbits with 28 days of axial compression and following 28 days of axial distraction (D, measurement at day 56). Disc compression and distraction was verified by disc height in lateral radiographs. The controls (N) showed a level-related range between 0.25 MPa-0.45 MPa. The IVD pressure was highest at level L3/4 (0.42 MPa; range 0.38-0.45) with a decrease in both cranial and caudal adjacent segments. The result for C was a significant decrease in IVD pressure (0.31 MPa) when compared with controls (P=0.009). D showed slightly higher median IVD pressure (0.32 MPa) compared to C, but significantly lower levels when compared with N (P=0.037). Our results indicate a high range of physiological IVD pressure at different levels of the lumbar rabbit spine. Temporary disc compression reduces pressure when compared with controls. These data support the hypothesis that temporary external compression leads to moderate disc degeneration as a result of degradation of water-binding disc matrix or affected active pumping mechanisms of nutrients into the disc. A stabilization of IVD pressure in discs treated with temporary distraction was observed. (+info)Regulation of matrix metalloproteinase expression by dynamic tensile strain in rat fibrochondrocytes. (8/83)
OBJECTIVE: We sought to determine the molecular basis for the anticatabolic effects of mechanical signals on fibrocartilage cells by studying the expression of a variety of matrix metalloproteinases (MMPs). Furthermore, we examined whether the effects of biomechanical strain on MMP gene expression are sustained. METHODS: Fibrochondrocytes from temporomandibular joint (TMJ) discs were exposed to dynamic tensile strain for various time intervals in the presence of interleukin (IL)-1beta. The regulation of the messenger RNA (mRNA) expression and synthesis of MMPs and tissue inhibitors of MMPs (TIMPs) were examined by end-point and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) as well as Western blot analysis. RESULTS: Fibrochondrocytes expressed mRNA for MMP-2, -3, -7, -8, -9, -11, -13, -14, -16, -17, and -19 as well as TIMP-1, -2, and -3, IL-1beta induced a significant (P<0.05) upregulation of mRNA for MMP-3, -7, -8, -9, -13, -16, -17, and -19. The IL-1beta-stimulated upregulation of these MMPs was significantly (P<0.05) abrogated by dynamic tensile strain. However, MMP-2, -11, -14, and TIMPs were not affected by either IL-1beta or tensile strain. Biomechanical strain also inhibited the IL-1beta-stimulated protein synthesis of MMP-3, -7, -8, -9, -13, -16, and -17. Application of mechanical strain for various time intervals during a 24-h incubation with IL-1beta showed that the suppressive effects of mechanical signals are sustained. CONCLUSIONS: The data provide evidence that biomechanical signals can downregulate the catabolic activity of fibrocartilage cells in an inflammatory environment by inhibiting the expression of a variety of MMPs. Furthermore, the matrix-protective effects of biomechanical signals are sustained even in an inflammatory environment. (+info)Fibrocartilage is a type of tough, dense connective tissue that contains both collagen fibers and cartilaginous matrix. It is composed of fibroblasts embedded in a extracellular matrix rich in collagen types I and II, proteoglycans and elastin. Fibrocartilage is found in areas of the body where strong, flexible support is required, such as intervertebral discs, menisci (knee cartilage), labrum (shoulder and hip cartilage) and pubic symphysis. It has both the elasticity and flexibility of cartilage and the strength and durability of fibrous tissue. Fibrocartilage can withstand high compressive loads and provides cushioning, shock absorption and stability to the joints and spine.
The triangular fibrocartilage complex (TFCC) is a structure located in the wrist, more specifically at the junction between the ulna bone of the forearm and the wrist bones (carpals). It consists of several components including:
* The triangular fibrocartilage disc: A piece of cartilage that provides shock absorption and helps to distribute forces across the wrist.
* The meniscal homologue: A small structure similar to a meniscus found in some other joints, which also helps with force distribution.
* The ulnar collateral ligament: A ligament that supports the medial (ulnar) side of the wrist.
* The extensor carpi ulnaris tendon sheath and subsynovial connective tissue: These structures provide stability to the TFCC and allow for smooth movement of the tendons in this area.
The primary function of the TFCC is to maintain the stability of the distal radioulnar joint (the joint between the ulna bone and one of the wrist bones) and to distribute loads transmitted across the wrist, particularly during rotational movements of the forearm. Injuries or degeneration of the TFCC can lead to pain, stiffness, and decreased grip strength in the affected wrist.
A tendon is the strong, flexible band of tissue that connects muscle to bone. It helps transfer the force produced by the muscle to allow various movements of our body parts. Tendons are made up of collagen fibers arranged in parallel bundles and have a poor blood supply, making them prone to injuries and slow to heal. Examples include the Achilles tendon, which connects the calf muscle to the heel bone, and the patellar tendon, which connects the kneecap to the shinbone.
The wrist joint, also known as the radiocarpal joint, is a condyloid joint that connects the distal end of the radius bone in the forearm to the proximal row of carpal bones in the hand (scaphoid, lunate, and triquetral bones). It allows for flexion, extension, radial deviation, and ulnar deviation movements of the hand. The wrist joint is surrounded by a capsule and reinforced by several ligaments that provide stability and strength to the joint.
Articular ligaments, also known as fibrous ligaments, are bands of dense, fibrous connective tissue that connect and stabilize bones to each other at joints. They help to limit the range of motion of a joint and provide support, preventing excessive movement that could cause injury. Articular ligaments are composed mainly of collagen fibers arranged in a parallel pattern, making them strong and flexible. They have limited blood supply and few nerve endings, which makes them less prone to injury but also slower to heal if damaged. Examples of articular ligaments include the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) in the knee joint, and the medial collateral ligament (MCL) and lateral collateral ligament (LCL) in the elbow joint.
Wrist injuries refer to damages or traumas affecting the structures of the wrist, including bones, ligaments, tendons, muscles, and cartilage. These injuries can occur due to various reasons such as falls, accidents, sports-related impacts, or repetitive stress. Common types of wrist injuries include fractures (such as scaphoid fracture), sprains (like ligament tears), strains (involving muscles or tendons), dislocations, and carpal tunnel syndrome. Symptoms may include pain, swelling, tenderness, bruising, limited mobility, and in severe cases, deformity or numbness. Immediate medical attention is necessary for proper diagnosis and treatment to ensure optimal recovery and prevent long-term complications.
The ulna is one of the two long bones in the forearm, the other being the radius. It runs from the elbow to the wrist and is located on the medial side of the forearm, next to the bone called the humerus in the upper arm. The ulna plays a crucial role in the movement of the forearm and also serves as an attachment site for various muscles.
Cartilage is a type of connective tissue that is found throughout the body in various forms. It is made up of specialized cells called chondrocytes, which are embedded in a firm, flexible matrix composed of collagen fibers and proteoglycans. This unique structure gives cartilage its characteristic properties of being both strong and flexible.
There are three main types of cartilage in the human body: hyaline cartilage, elastic cartilage, and fibrocartilage.
1. Hyaline cartilage is the most common type and is found in areas such as the articular surfaces of bones (where they meet to form joints), the nose, trachea, and larynx. It has a smooth, glassy appearance and provides a smooth, lubricated surface for joint movement.
2. Elastic cartilage contains more elastin fibers than hyaline cartilage, which gives it greater flexibility and resilience. It is found in structures such as the external ear and parts of the larynx and epiglottis.
3. Fibrocartilage has a higher proportion of collagen fibers and fewer chondrocytes than hyaline or elastic cartilage. It is found in areas that require high tensile strength, such as the intervertebral discs, menisci (found in joints like the knee), and the pubic symphysis.
Cartilage plays a crucial role in supporting and protecting various structures within the body, allowing for smooth movement and providing a cushion between bones to absorb shock and prevent wear and tear. However, cartilage has limited capacity for self-repair and regeneration, making damage or degeneration of cartilage tissue a significant concern in conditions such as osteoarthritis.
Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints. It provides a cushion between bones and allows for smooth movement by reducing friction. Articular cartilage also absorbs shock and distributes loads evenly across the joint, protecting the bones from damage. It is avascular, meaning it does not have its own blood supply, and relies on the surrounding synovial fluid for nutrients. Over time, articular cartilage can wear down or become damaged due to injury or disease, leading to conditions such as osteoarthritis.
Ligaments are bands of dense, fibrous connective tissue that surround joints and provide support, stability, and limits the range of motion. They are made up primarily of collagen fibers arranged in a parallel pattern to withstand tension and stress. Ligaments attach bone to bone, and their function is to prevent excessive movement that could cause injury or dislocation.
There are two main types of ligaments: extracapsular and intracapsular. Extracapsular ligaments are located outside the joint capsule and provide stability to the joint by limiting its range of motion. Intracapsular ligaments, on the other hand, are found inside the joint capsule and help maintain the alignment of the joint surfaces.
Examples of common ligaments in the body include the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) in the knee, the medial collateral ligament (MCL) and lateral collateral ligament (LCL) in the elbow, and the coracoacromial ligament in the shoulder.
Injuries to ligaments can occur due to sudden trauma or overuse, leading to sprains, strains, or tears. These injuries can cause pain, swelling, bruising, and limited mobility, and may require medical treatment such as immobilization, physical therapy, or surgery.
Aggrecan is a large, complex proteoglycan molecule found in the extracellular matrix of articular cartilage and other connective tissues. It is a key component of the structural framework of these tissues, helping to provide resiliency, cushioning, and protection to the cells within. Aggrecan contains numerous glycosaminoglycan (GAG) chains, which are negatively charged molecules that attract water and ions, creating a swelling pressure that contributes to the tissue's load-bearing capacity.
The medical definition of 'Aggrecans' can be described as:
1. A large proteoglycan molecule found in articular cartilage and other connective tissues.
2. Composed of a core protein with attached glycosaminoglycan (GAG) chains, primarily chondroitin sulfate and keratan sulfate.
3. Plays a crucial role in the biomechanical properties of articular cartilage by attracting water and ions, creating a swelling pressure that contributes to the tissue's load-bearing capacity.
4. Aggrecan degradation or loss is associated with various joint diseases, such as osteoarthritis, due to reduced structural integrity and shock-absorbing capabilities of articular cartilage.
Hyaline cartilage is a type of cartilaginous tissue that is primarily found in the articulating surfaces of bones, ribcage, nose, ears, and trachea. It has a smooth, glassy appearance (hence the name "hyaline," derived from the Greek word "hyalos" meaning glass) due to the presence of type II collagen fibers that are arranged in a precise pattern and embedded in a proteoglycan-rich matrix.
The high concentration of proteoglycans, which are complex molecules made up of a protein core and glycosaminoglycan side chains, gives hyaline cartilage its firm yet flexible properties. This type of cartilage is avascular, meaning it does not contain blood vessels, and receives nutrients through diffusion from the surrounding synovial fluid in joints or adjacent tissues.
Hyaline cartilage plays a crucial role in providing structural support, reducing friction between articulating bones, and facilitating smooth movement in joints. It also serves as a template for endochondral ossification, a process by which long bones grow in length during development.
A rupture, in medical terms, refers to the breaking or tearing of an organ, tissue, or structure in the body. This can occur due to various reasons such as trauma, injury, increased pressure, or degeneration. A ruptured organ or structure can lead to serious complications, including internal bleeding, infection, and even death, if not treated promptly and appropriately. Examples of ruptures include a ruptured appendix, ruptured eardrum, or a ruptured disc in the spine.
The patellar ligament, also known as the patellar tendon, is a strong band of tissue that connects the bottom part of the kneecap (patella) to the top part of the shinbone (tibia). This ligament plays a crucial role in enabling the extension and straightening of the leg during activities such as walking, running, and jumping. Injuries to the patellar ligament, such as tendonitis or tears, can cause pain and difficulty with mobility.
The patella, also known as the kneecap, is a sesamoid bone located at the front of the knee joint. It is embedded in the tendon of the quadriceps muscle and serves to protect the knee joint and increase the leverage of the extensor mechanism, allowing for greater extension force of the lower leg. The patella moves within a groove on the femur called the trochlea during flexion and extension of the knee.
Keratan sulfate is a type of glycosaminoglycan (GAG), which is a complex carbohydrate found in connective tissues, including the cornea and cartilage. It is composed of repeating disaccharide units of galactose and N-acetylglucosamine, with sulfate groups attached to some of the sugar molecules.
Keratan sulfate is unique among GAGs because it contains a high proportion of non-sulfated sugars and is often found covalently linked to proteins in structures called proteoglycans. In the cornea, keratan sulfate plays important roles in maintaining transparency and regulating hydration. In cartilage, it contributes to the elasticity and resilience of the tissue.
Abnormalities in keratan sulfate metabolism have been associated with several genetic disorders, including corneal dystrophies and skeletal dysplasias.
The menisci are crescent-shaped fibrocartilaginous structures located in the knee joint. There are two menisci in each knee: the medial meniscus and the lateral meniscus. The tibial menisci, also known as the medial and lateral menisci, are named according to their location in the knee joint. They lie on the top surface of the tibia (shin bone) and provide shock absorption, stability, and lubrication to the knee joint.
The tibial menisci have a complex shape, with a wider outer portion called the peripheral rim and a narrower inner portion called the central portion or root attachment. The menisci are attached to the bones of the knee joint by ligaments and have a rich blood supply in their outer portions, which helps in healing after injury. However, the inner two-thirds of the menisci have a poor blood supply, making them more prone to degeneration and less likely to heal after injury.
Damage to the tibial menisci can occur due to trauma or degenerative changes, leading to symptoms such as pain, swelling, stiffness, and limited mobility of the knee joint. Treatment for meniscal injuries may include physical therapy, bracing, or surgery, depending on the severity and location of the injury.
Tissue engineering is a branch of biomedical engineering that combines the principles of engineering, materials science, and biological sciences to develop functional substitutes for damaged or diseased tissues and organs. It involves the creation of living, three-dimensional structures that can restore, maintain, or improve tissue function. This is typically accomplished through the use of cells, scaffolds (biodegradable matrices), and biologically active molecules. The goal of tissue engineering is to develop biological substitutes that can ultimately restore normal function and structure in damaged tissues or organs.
The pubic symphysis is the joint in the front of the pelvis that connects the two halves of the pelvic girdle, specifically the pubic bones. It's located at the lower part of the anterior (front) pelvic region. Unlike most joints, which are movable and contain synovial fluid, the pubic symphysis is a cartilaginous joint, also known as an amphiarthrosis.
The joint consists of fibrocartilaginous discs, ligaments, and the articular surfaces of the adjacent pubic bones. The fibrocartilaginous disc helps to absorb shock and reduce friction between the two bones. The main function of the pubic symphysis is to provide stability for the pelvis and transfer weight and forces from the upper body to the lower limbs during activities like walking, running, or jumping.
The pubic symphysis has a limited range of motion, allowing only slight movement in response to pressure or tension. During pregnancy and childbirth, the hormone relaxin is released, which increases the laxity of the pelvic joints, including the pubic symphysis, to accommodate the growing fetus and facilitate delivery. This increased mobility can sometimes lead to discomfort or pain in the area, known as symphysis pubis dysfunction (SPD) or pelvic girdle pain.
The temporomandibular joint (TMJ) is the articulation between the mandible (lower jaw) and the temporal bone of the skull. It's a complex joint that involves the movement of two bones, several muscles, and various ligaments. The TMJ allows for movements like rotation and translation, enabling us to open and close our mouth, chew, speak, and yawn. Dysfunction in this joint can lead to temporomandibular joint disorders (TMD), which can cause pain, discomfort, and limited jaw movement.
Physiologic calcification is the normal deposit of calcium salts in body tissues and organs. It is a natural process that occurs as part of the growth and development of the human body, as well as during the repair and remodeling of tissues.
Calcium is an essential mineral that plays a critical role in many bodily functions, including bone formation, muscle contraction, nerve impulse transmission, and blood clotting. In order to maintain proper levels of calcium in the body, excess calcium that is not needed for these functions may be deposited in various tissues as a normal part of the aging process.
Physiologic calcification typically occurs in areas such as the walls of blood vessels, the lungs, and the heart valves. While these calcifications are generally harmless, they can sometimes lead to complications, particularly if they occur in large amounts or in sensitive areas. For example, calcification of the coronary arteries can increase the risk of heart disease, while calcification of the lung tissue can cause respiratory symptoms.
It is important to note that pathologic calcification, on the other hand, refers to the abnormal deposit of calcium salts in tissues and organs, which can be caused by various medical conditions such as chronic kidney disease, hyperparathyroidism, and certain infections. Pathologic calcification is not a normal process and can lead to serious health complications if left untreated.
The periosteum is a highly vascularized and innervated tissue that surrounds the outer surface of bones, except at the articular surfaces. It consists of two layers: an outer fibrous layer containing blood vessels, nerves, and fibroblasts; and an inner cellular layer called the cambium or osteogenic layer, which contains progenitor cells capable of bone formation and repair.
The periosteum plays a crucial role in bone growth, remodeling, and healing by providing a source of osteoprogenitor cells and blood supply. It also contributes to the sensation of pain in response to injury or inflammation of the bone. Additionally, the periosteum can respond to mechanical stress by activating bone formation, making it an essential component in orthopedic treatments such as distraction osteogenesis.
The temporomandibular joint (TMJ) disc is a small, thin piece of fibrocartilaginous tissue located within the TMJ, which is the joint that connects the mandible (jawbone) to the temporal bone of the skull. The disc acts as a cushion and allows for smooth movement of the jaw during activities such as eating, speaking, and yawning. It divides the joint into two compartments: the upper and lower compartments.
The TMJ disc is composed of several types of tissue, including collagen fibers, elastin fibers, and a small number of cells called fibroblasts. The disc's unique structure allows it to withstand the forces generated during jaw movement and helps to distribute these forces evenly across the joint.
The TMJ disc can become damaged or displaced due to various factors such as trauma, teeth grinding (bruxism), or degenerative joint diseases like osteoarthritis. This can lead to temporomandibular disorders (TMDs) characterized by pain, stiffness, and limited jaw movement.
Arthroscopy is a minimally invasive surgical procedure where an orthopedic surgeon uses an arthroscope (a thin tube with a light and camera on the end) to diagnose and treat problems inside a joint. The surgeon makes a small incision, inserts the arthroscope into the joint, and then uses the attached camera to view the inside of the joint on a monitor. They can then insert other small instruments through additional incisions to repair or remove damaged tissue.
Arthroscopy is most commonly used for joints such as the knee, shoulder, hip, ankle, and wrist. It offers several advantages over traditional open surgery, including smaller incisions, less pain and bleeding, faster recovery time, and reduced risk of infection. The procedure can be used to diagnose and treat a wide range of conditions, including torn ligaments or cartilage, inflamed synovial tissue, loose bone or cartilage fragments, and joint damage caused by arthritis.
Compressive strength is a measure of the maximum compressive load that a material or structure can withstand before failure or deformation. It is typically expressed in units of pressure, such as pounds per square inch (psi) or megapascals (MPa). Compressive strength is an important property in the design and analysis of structures and materials, as it helps to ensure their safety and durability under compressive loads.
In medical terminology, compressive strength may refer to the ability of biological tissues, such as bone or cartilage, to withstand compressive forces without deforming or failing. For example, osteoporosis is a condition characterized by reduced bone density and compressive strength, which can increase the risk of fractures in affected individuals. Similarly, degenerative changes in articular cartilage can lead to decreased compressive strength and joint pain or stiffness.
Collagen Type II is a specific type of collagen that is a major component of the extracellular matrix in articular cartilage, which is the connective tissue that covers and protects the ends of bones in joints. It is also found in other tissues such as the vitreous humor of the eye and the inner ear.
Collagen Type II is a triple helix molecule composed of three polypeptide chains that contain a high proportion of the amino acids proline and hydroxyproline. This type of collagen provides structural support and elasticity to tissues, and it also plays a role in the regulation of cell behavior and signaling.
Collagen Type II is a target for autoimmune responses in conditions such as rheumatoid arthritis, where the immune system mistakenly attacks the body's own collagen, leading to joint inflammation and damage. It is also a common component of various dietary supplements and therapies used to support joint health and treat osteoarthritis.
The Achilles tendon, also known as the calcaneal tendon, is a strong band of tissue that connects the calf muscles to the heel bone (calcaneus). It plays a crucial role in enabling activities such as walking, running, and jumping by facilitating the movement of the foot downward, which is called plantar flexion. Injuries to the Achilles tendon, such as tendinitis or ruptures, can be quite painful and impact mobility.
Glycosaminoglycans (GAGs) are long, unbranched polysaccharides composed of repeating disaccharide units. They are a major component of the extracellular matrix and connective tissues in the body. GAGs are negatively charged due to the presence of sulfate and carboxyl groups, which allows them to attract positively charged ions and water molecules, contributing to their ability to retain moisture and maintain tissue hydration and elasticity.
GAGs can be categorized into four main groups: heparin/heparan sulfate, chondroitin sulfate/dermatan sulfate, keratan sulfate, and hyaluronic acid. These different types of GAGs have varying structures and functions in the body, including roles in cell signaling, inflammation, and protection against enzymatic degradation.
Heparin is a highly sulfated form of heparan sulfate that is found in mast cells and has anticoagulant properties. Chondroitin sulfate and dermatan sulfate are commonly found in cartilage and contribute to its resiliency and ability to withstand compressive forces. Keratan sulfate is found in corneas, cartilage, and bone, where it plays a role in maintaining the structure and function of these tissues. Hyaluronic acid is a large, nonsulfated GAG that is widely distributed throughout the body, including in synovial fluid, where it provides lubrication and shock absorption for joints.
Chondrocalcinosis is a medical condition characterized by the deposition of calcium pyrophosphate dihydrate crystals in the fibrous cartilage (also known as chondral or articular cartilage) and/or the joint cavity (synovial fluid). This cartilage is present in various parts of the body, including the ears, nose, respiratory tract, and connective tissues such as those found in joints.
Calcium pyrophosphate dihydrate crystals are normally present in small amounts within the body; however, an overabundance of these crystals can lead to chondrocalcinosis. The condition is often associated with osteoarthritis and can affect people of all ages but is more common in older adults.
Chondrocalcinosis may not always cause symptoms, but when it does, they can include joint pain, stiffness, swelling, and warmth. These symptoms are similar to those seen in other forms of arthritis, making chondrocalcinosis difficult to diagnose based on symptoms alone. Diagnosis typically involves imaging techniques such as X-rays or ultrasounds, as well as joint fluid analysis to identify the presence of calcium pyrophosphate dihydrate crystals.
Treatment for chondrocalcinosis is generally focused on managing symptoms and addressing any underlying conditions that may contribute to the development or progression of the disease. This can include medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation, joint aspiration to remove excess fluid and crystals from the affected area, and physical therapy to maintain joint mobility and strength. In some cases, surgery may be necessary to repair or replace damaged joints.
The epiphyses are the rounded ends of long bones in the body, which articulate with other bones to form joints. They are separated from the main shaft of the bone (diaphysis) by a growth plate called the physis or epiphyseal plate. The epiphyses are made up of spongy bone and covered with articular cartilage, which allows for smooth movement between bones. During growth, the epiphyseal plates produce new bone cells that cause the bone to lengthen until they eventually fuse during adulthood, at which point growth stops.
Collagen is the most abundant protein in the human body, and it is a major component of connective tissues such as tendons, ligaments, skin, and bones. Collagen provides structure and strength to these tissues and helps them to withstand stretching and tension. It is made up of long chains of amino acids, primarily glycine, proline, and hydroxyproline, which are arranged in a triple helix structure. There are at least 16 different types of collagen found in the body, each with slightly different structures and functions. Collagen is important for maintaining the integrity and health of tissues throughout the body, and it has been studied for its potential therapeutic uses in various medical conditions.
The mandibular condyle is a part of the temporomandibular joint (TMJ) in the human body. It is a rounded eminence at the end of the mandible (lower jawbone) that articulates with the glenoid fossa of the temporal bone in the skull, allowing for movements such as opening and closing the mouth, chewing, speaking, and swallowing. The mandibular condyle has both a fibrocartilaginous articular surface and a synovial joint capsule surrounding it, which provides protection and lubrication during these movements.
Biomechanics is the application of mechanical laws to living structures and systems, particularly in the field of medicine and healthcare. A biomechanical phenomenon refers to a observable event or occurrence that involves the interaction of biological tissues or systems with mechanical forces. These phenomena can be studied at various levels, from the molecular and cellular level to the tissue, organ, and whole-body level.
Examples of biomechanical phenomena include:
1. The way that bones and muscles work together to produce movement (known as joint kinematics).
2. The mechanical behavior of biological tissues such as bone, cartilage, tendons, and ligaments under various loads and stresses.
3. The response of cells and tissues to mechanical stimuli, such as the way that bone tissue adapts to changes in loading conditions (known as Wolff's law).
4. The biomechanics of injury and disease processes, such as the mechanisms of joint injury or the development of osteoarthritis.
5. The use of mechanical devices and interventions to treat medical conditions, such as orthopedic implants or assistive devices for mobility impairments.
Understanding biomechanical phenomena is essential for developing effective treatments and prevention strategies for a wide range of medical conditions, from musculoskeletal injuries to neurological disorders.
The metacarpophalangeal (MCP) joint is the joint that connects the bones of the hand (metacarpals) to the bones of the fingers and thumb (phalanges). It's also commonly referred to as the "knuckle" joint. The MCP joint allows for flexion, extension, abduction, and adduction movements of the fingers and thumb. It is a synovial joint, which means it contains a lubricating fluid called synovial fluid that helps reduce friction during movement.
Versican is a type of proteoglycan, which is a complex protein molecule that contains one or more long sugar chains (glycosaminoglycans) attached to it. Proteoglycans are important components of the extracellular matrix (the material that provides structural support and regulates cell behavior in tissues and organs).
Versican is primarily found in the extracellular matrix of connective tissues, including skin, tendons, ligaments, and blood vessels. It plays a role in regulating cell adhesion, migration, and proliferation, as well as in maintaining the structural integrity of tissues. Versican has been implicated in various physiological and pathological processes, such as embryonic development, wound healing, inflammation, and cancer progression.
There are several isoforms of versican (V0, V1, V2, and V3) that differ in their structure and function, depending on the specific glycosaminoglycan chains attached to them. Abnormal expression or regulation of versican has been associated with various diseases, including cancer, fibrosis, and inflammatory disorders.
Tissue scaffolds, also known as bioactive scaffolds or synthetic extracellular matrices, refer to three-dimensional structures that serve as templates for the growth and organization of cells in tissue engineering and regenerative medicine. These scaffolds are designed to mimic the natural extracellular matrix (ECM) found in biological tissues, providing a supportive environment for cell attachment, proliferation, differentiation, and migration.
Tissue scaffolds can be made from various materials, including naturally derived biopolymers (e.g., collagen, alginate, chitosan, hyaluronic acid), synthetic polymers (e.g., polycaprolactone, polylactic acid, poly(lactic-co-glycolic acid)), or a combination of both. The choice of material depends on the specific application and desired properties, such as biocompatibility, biodegradability, mechanical strength, and porosity.
The primary functions of tissue scaffolds include:
1. Cell attachment: Providing surfaces for cells to adhere, spread, and form stable focal adhesions.
2. Mechanical support: Offering a structural framework that maintains the desired shape and mechanical properties of the engineered tissue.
3. Nutrient diffusion: Ensuring adequate transport of nutrients, oxygen, and waste products throughout the scaffold to support cell survival and function.
4. Guided tissue growth: Directing the organization and differentiation of cells through spatial cues and biochemical signals.
5. Biodegradation: Gradually degrading at a rate that matches tissue regeneration, allowing for the replacement of the scaffold with native ECM produced by the cells.
Tissue scaffolds have been used in various applications, such as wound healing, bone and cartilage repair, cardiovascular tissue engineering, and neural tissue regeneration. The design and fabrication of tissue scaffolds are critical aspects of tissue engineering, aiming to create functional substitutes for damaged or diseased tissues and organs.
Cartilage diseases refer to conditions that affect the cartilaginous tissues in the body. Cartilage is a firm, flexible connective tissue found in many areas of the body, including the joints, ribcage, ears, and nose. It provides structure and support, allows for smooth movement between bones, and protects the ends of bones from friction.
There are several types of cartilage diseases, including:
1. Osteoarthritis (OA): This is a degenerative joint disease that occurs when the protective cartilage that cushions the ends of your bones wears down over time. It can cause pain, stiffness, and loss of mobility in the affected joints.
2. Rheumatoid arthritis (RA): This is an autoimmune disorder that causes inflammation in the lining of the joints, leading to cartilage damage and bone erosion.
3. Traumatic arthritis: This occurs when a joint is injured, causing damage to the cartilage and resulting in pain, stiffness, and loss of mobility.
4. Infectious arthritis: This occurs when a joint becomes infected, leading to inflammation and potential damage to the cartilage.
5. Chondromalacia patellae: This is a condition that affects the cartilage on the back of the kneecap, causing pain and stiffness in the knee.
6. Costochondritis: This is an inflammation of the cartilage in the ribcage, causing chest pain and discomfort.
7. Nasal septal deviation: This is a condition where the cartilage that separates the nostrils is crooked or off-center, causing difficulty breathing through the nose.
8. Osteochondritis dissecans (OCD): This is a joint condition that occurs when a piece of cartilage and bone in a joint becomes detached, causing pain and stiffness.
9. Synovial chondromatosis: This is a rare condition where nodules made up of cartilage form in the lining of a joint, causing pain, swelling, and limited mobility.
Treatment for cartilage diseases varies depending on the specific condition and severity, but may include medication, physical therapy, surgery, or a combination of these.
Arthrography is a medical imaging technique used to diagnose problems within joints. It involves the injection of a contrast agent, such as a radiopaque dye or air, into the joint space, followed by the use of fluoroscopy or X-ray imaging to visualize the internal structures of the joint. This can help to identify injuries, tears, or other abnormalities in the cartilage, ligaments, tendons, or bones within the joint.
The procedure is typically performed on an outpatient basis and may be used to diagnose conditions such as shoulder dislocations, rotator cuff tears, meniscal tears in the knee, or hip labral injuries. It is a relatively safe and minimally invasive procedure, although there may be some temporary discomfort or swelling at the injection site. Patients are usually advised to avoid strenuous activity for a day or two following the procedure to allow the contrast agent to fully dissipate from the joint.
The Anterior Cruciate Ligament (ACL) is a major stabilizing ligament in the knee. It is one of the four strong bands of tissue that connect the bones of the knee joint together. The ACL runs diagonally through the middle of the knee and helps to control the back and forth motion of the knee, as well as provide stability to the knee joint. Injuries to the ACL often occur during sports or physical activities that involve sudden stops, changes in direction, or awkward landings.
Joint diseases is a broad term that refers to various conditions affecting the joints, including but not limited to:
1. Osteoarthritis (OA): A degenerative joint disease characterized by the breakdown of cartilage and underlying bone, leading to pain, stiffness, and potential loss of function.
2. Rheumatoid Arthritis (RA): An autoimmune disorder causing inflammation in the synovial membrane lining the joints, resulting in swelling, pain, and joint damage if left untreated.
3. Infectious Arthritis: Joint inflammation caused by bacterial, viral, or fungal infections that spread through the bloodstream or directly enter the joint space.
4. Gout: A type of arthritis resulting from the buildup of uric acid crystals in the joints, typically affecting the big toe and characterized by sudden attacks of severe pain, redness, and swelling.
5. Psoriatic Arthritis (PsA): An inflammatory joint disease associated with psoriasis, causing symptoms such as pain, stiffness, and swelling in the joints and surrounding tissues.
6. Juvenile Idiopathic Arthritis (JIA): A group of chronic arthritis conditions affecting children, characterized by joint inflammation, pain, and stiffness.
7. Ankylosing Spondylitis: A form of arthritis primarily affecting the spine, causing inflammation, pain, and potential fusion of spinal vertebrae.
8. Bursitis: Inflammation of the fluid-filled sacs (bursae) that cushion joints, leading to pain and swelling.
9. Tendinitis: Inflammation or degeneration of tendons, which connect muscles to bones, often resulting in pain and stiffness near joints.
These conditions can impact the function and mobility of affected joints, causing discomfort and limiting daily activities. Proper diagnosis and treatment are essential for managing joint diseases and preserving joint health.
Chondrogenesis is the process of cartilage formation during embryonic development and in the healing of certain types of injuries. It involves the differentiation of mesenchymal stem cells into chondrocytes, which are the specialized cells that produce and maintain the extracellular matrix of cartilage.
During chondrogenesis, the mesenchymal stem cells condense and form a template for the future cartilaginous tissue. These cells then differentiate into chondrocytes, which begin to produce and deposit collagen type II, proteoglycans, and other extracellular matrix components that give cartilage its unique biochemical and mechanical properties.
Chondrogenesis is a critical process for the development of various structures in the body, including the skeletal system, where it plays a role in the formation of articular cartilage, growth plates, and other types of cartilage. Understanding the molecular mechanisms that regulate chondrogenesis is important for developing therapies to treat cartilage injuries and degenerative diseases such as osteoarthritis.
Dermatan sulfate is a type of glycosaminoglycan, which is a long, unbranched sugar chain found on the proteoglycan core protein in the extracellular matrix of animal tissues. It is composed of repeating disaccharide units of iduronic acid and N-acetylgalactosamine, with alternating sulfation at the 4-position of the iduronic acid and the 6-position of the galactosamine.
Dermatan sulfate is found in various tissues, including skin, heart valves, and blood vessels, where it plays important roles in regulating cell behavior, tissue development, and homeostasis. It also binds to a variety of growth factors, cytokines, and enzymes, modulating their activities and contributing to the regulation of various biological processes.
Abnormalities in dermatan sulfate metabolism can lead to several genetic disorders, such as Hunter syndrome and Hurler-Scheie syndrome, which are characterized by skeletal abnormalities, cardiac defects, and neurological impairment.
Chondroitin sulfates are a type of complex carbohydrate molecules known as glycosaminoglycans (GAGs). They are a major component of cartilage, the tissue that cushions and protects the ends of bones in joints. Chondroitin sulfates are composed of repeating disaccharide units made up of glucuronic acid and N-acetylgalactosamine, which can be sulfated at various positions.
Chondroitin sulfates play a crucial role in the biomechanical properties of cartilage by attracting water and maintaining the resiliency and elasticity of the tissue. They also interact with other molecules in the extracellular matrix, such as collagen and proteoglycans, to form a complex network that provides structural support and regulates cell behavior.
Chondroitin sulfates have been studied for their potential therapeutic benefits in osteoarthritis, a degenerative joint disease characterized by the breakdown of cartilage. Supplementation with chondroitin sulfate has been shown to reduce pain and improve joint function in some studies, although the evidence is not consistent across all trials. The mechanism of action is thought to involve inhibition of enzymes that break down cartilage, as well as stimulation of cartilage repair and synthesis.
Proteoglycans are complex, highly negatively charged macromolecules that are composed of a core protein covalently linked to one or more glycosaminoglycan (GAG) chains. They are a major component of the extracellular matrix (ECM) and play crucial roles in various biological processes, including cell signaling, regulation of growth factor activity, and maintenance of tissue structure and function.
The GAG chains, which can vary in length and composition, are long, unbranched polysaccharides that are composed of repeating disaccharide units containing a hexuronic acid (either glucuronic or iduronic acid) and a hexosamine (either N-acetylglucosamine or N-acetylgalactosamine). These GAG chains can be sulfated to varying degrees, which contributes to the negative charge of proteoglycans.
Proteoglycans are classified into four major groups based on their core protein structure and GAG composition: heparan sulfate/heparin proteoglycans, chondroitin/dermatan sulfate proteoglycans, keratan sulfate proteoglycans, and hyaluronan-binding proteoglycans. Each group has distinct functions and is found in specific tissues and cell types.
In summary, proteoglycans are complex macromolecules composed of a core protein and one or more GAG chains that play important roles in the ECM and various biological processes, including cell signaling, growth factor regulation, and tissue structure maintenance.
Chondrocytes are the specialized cells that produce and maintain the extracellular matrix of cartilage tissue. They are responsible for synthesizing and secreting the collagen fibers, proteoglycans, and other components that give cartilage its unique properties, such as elasticity, resiliency, and resistance to compression. Chondrocytes are located within lacunae, or small cavities, in the cartilage matrix, and they receive nutrients and oxygen through diffusion from the surrounding tissue fluid. They are capable of adapting to changes in mechanical stress by modulating the production and organization of the extracellular matrix, which allows cartilage to withstand various loads and maintain its structural integrity. Chondrocytes play a crucial role in the development, maintenance, and repair of cartilaginous tissues throughout the body, including articular cartilage, costal cartilage, and growth plate cartilage.
Extracellular matrix (ECM) proteins are a group of structural and functional molecules that provide support, organization, and regulation to the cells in tissues and organs. The ECM is composed of a complex network of proteins, glycoproteins, and carbohydrates that are secreted by the cells and deposited outside of them.
ECM proteins can be classified into several categories based on their structure and function, including:
1. Collagens: These are the most abundant ECM proteins and provide strength and stability to tissues. They form fibrils that can withstand high tensile forces.
2. Proteoglycans: These are complex molecules made up of a core protein and one or more glycosaminoglycan (GAG) chains. The GAG chains attract water, making proteoglycans important for maintaining tissue hydration and resilience.
3. Elastin: This is an elastic protein that allows tissues to stretch and recoil, such as in the lungs and blood vessels.
4. Fibronectins: These are large glycoproteins that bind to cells and ECM components, providing adhesion, migration, and signaling functions.
5. Laminins: These are large proteins found in basement membranes, which provide structural support for epithelial and endothelial cells.
6. Tenascins: These are large glycoproteins that modulate cell adhesion and migration, and regulate ECM assembly and remodeling.
Together, these ECM proteins create a microenvironment that influences cell behavior, differentiation, and function. Dysregulation of ECM proteins has been implicated in various diseases, including fibrosis, cancer, and degenerative disorders.
Mechanical stress, in the context of physiology and medicine, refers to any type of force that is applied to body tissues or organs, which can cause deformation or displacement of those structures. Mechanical stress can be either external, such as forces exerted on the body during physical activity or trauma, or internal, such as the pressure changes that occur within blood vessels or other hollow organs.
Mechanical stress can have a variety of effects on the body, depending on the type, duration, and magnitude of the force applied. For example, prolonged exposure to mechanical stress can lead to tissue damage, inflammation, and chronic pain. Additionally, abnormal or excessive mechanical stress can contribute to the development of various musculoskeletal disorders, such as tendinitis, osteoarthritis, and herniated discs.
In order to mitigate the negative effects of mechanical stress, the body has a number of adaptive responses that help to distribute forces more evenly across tissues and maintain structural integrity. These responses include changes in muscle tone, joint positioning, and connective tissue stiffness, as well as the remodeling of bone and other tissues over time. However, when these adaptive mechanisms are overwhelmed or impaired, mechanical stress can become a significant factor in the development of various pathological conditions.
A cadaver is a deceased body that is used for medical research or education. In the field of medicine, cadavers are often used in anatomy lessons, surgical training, and other forms of medical research. The use of cadavers allows medical professionals to gain a deeper understanding of the human body and its various systems without causing harm to living subjects. Cadavers may be donated to medical schools or obtained through other means, such as through consent of the deceased or their next of kin. It is important to handle and treat cadavers with respect and dignity, as they were once living individuals who deserve to be treated with care even in death.
The knee joint, also known as the tibiofemoral joint, is the largest and one of the most complex joints in the human body. It is a synovial joint that connects the thighbone (femur) to the shinbone (tibia). The patella (kneecap), which is a sesamoid bone, is located in front of the knee joint and helps in the extension of the leg.
The knee joint is made up of three articulations: the femorotibial joint between the femur and tibia, the femoropatellar joint between the femur and patella, and the tibiofibular joint between the tibia and fibula. These articulations are surrounded by a fibrous capsule that encloses the synovial membrane, which secretes synovial fluid to lubricate the joint.
The knee joint is stabilized by several ligaments, including the medial and lateral collateral ligaments, which provide stability to the sides of the joint, and the anterior and posterior cruciate ligaments, which prevent excessive forward and backward movement of the tibia relative to the femur. The menisci, which are C-shaped fibrocartilaginous structures located between the femoral condyles and tibial plateaus, also help to stabilize the joint by absorbing shock and distributing weight evenly across the articular surfaces.
The knee joint allows for flexion, extension, and a small amount of rotation, making it essential for activities such as walking, running, jumping, and sitting.
The femur is the medical term for the thigh bone, which is the longest and strongest bone in the human body. It connects the hip bone to the knee joint and plays a crucial role in supporting the weight of the body and allowing movement during activities such as walking, running, and jumping. The femur is composed of a rounded head, a long shaft, and two condyles at the lower end that articulate with the tibia and patella to form the knee joint.
The "femur neck" is the narrow, upper part of the femur (thigh bone) where it connects to the pelvis. It is the region through which the femoral head articulates with the acetabulum to form the hip joint. The femur neck is a common site for fractures, especially in older adults with osteoporosis.
Wound healing is a complex and dynamic process that occurs after tissue injury, aiming to restore the integrity and functionality of the damaged tissue. It involves a series of overlapping phases: hemostasis, inflammation, proliferation, and remodeling.
1. Hemostasis: This initial phase begins immediately after injury and involves the activation of the coagulation cascade to form a clot, which stabilizes the wound and prevents excessive blood loss.
2. Inflammation: Activated inflammatory cells, such as neutrophils and monocytes/macrophages, infiltrate the wound site to eliminate pathogens, remove debris, and release growth factors that promote healing. This phase typically lasts for 2-5 days post-injury.
3. Proliferation: In this phase, various cell types, including fibroblasts, endothelial cells, and keratinocytes, proliferate and migrate to the wound site to synthesize extracellular matrix (ECM) components, form new blood vessels (angiogenesis), and re-epithelialize the wounded area. This phase can last up to several weeks depending on the size and severity of the wound.
4. Remodeling: The final phase of wound healing involves the maturation and realignment of collagen fibers, leading to the restoration of tensile strength in the healed tissue. This process can continue for months to years after injury, although the tissue may never fully regain its original structure and function.
It is important to note that wound healing can be compromised by several factors, including age, nutrition, comorbidities (e.g., diabetes, vascular disease), and infection, which can result in delayed healing or non-healing chronic wounds.
Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.
"Bone" is the hard, dense connective tissue that makes up the skeleton of vertebrate animals. It provides support and protection for the body's internal organs, and serves as a attachment site for muscles, tendons, and ligaments. Bone is composed of cells called osteoblasts and osteoclasts, which are responsible for bone formation and resorption, respectively, and an extracellular matrix made up of collagen fibers and mineral crystals.
Bones can be classified into two main types: compact bone and spongy bone. Compact bone is dense and hard, and makes up the outer layer of all bones and the shafts of long bones. Spongy bone is less dense and contains large spaces, and makes up the ends of long bones and the interior of flat and irregular bones.
The human body has 206 bones in total. They can be further classified into five categories based on their shape: long bones, short bones, flat bones, irregular bones, and sesamoid bones.
C-type lectins are a family of proteins that contain one or more carbohydrate recognition domains (CRDs) with a characteristic pattern of conserved sequence motifs. These proteins are capable of binding to specific carbohydrate structures in a calcium-dependent manner, making them important in various biological processes such as cell adhesion, immune recognition, and initiation of inflammatory responses.
C-type lectins can be further classified into several subfamilies based on their structure and function, including selectins, collectins, and immunoglobulin-like receptors. They play a crucial role in the immune system by recognizing and binding to carbohydrate structures on the surface of pathogens, facilitating their clearance by phagocytic cells. Additionally, C-type lectins are involved in various physiological processes such as cell development, tissue repair, and cancer progression.
It is important to note that some C-type lectins can also bind to self-antigens and contribute to autoimmune diseases. Therefore, understanding the structure and function of these proteins has important implications for developing new therapeutic strategies for various diseases.
Mesenchymal Stromal Cells (MSCs) are a type of adult stem cells found in various tissues, including bone marrow, adipose tissue, and umbilical cord blood. They have the ability to differentiate into multiple cell types, such as osteoblasts, chondrocytes, and adipocytes, under specific conditions. MSCs also possess immunomodulatory properties, making them a promising tool in regenerative medicine and therapeutic strategies for various diseases, including autoimmune disorders and tissue injuries. It is important to note that the term "Mesenchymal Stem Cells" has been replaced by "Mesenchymal Stromal Cells" in the scientific community to better reflect their biological characteristics and potential functions.
Osteoarthritis (OA) is a type of joint disease that is characterized by the breakdown and eventual loss of cartilage - the tissue that cushions the ends of bones where they meet in the joints. This breakdown can cause the bones to rub against each other, causing pain, stiffness, and loss of mobility. OA can occur in any joint, but it most commonly affects the hands, knees, hips, and spine. It is often associated with aging and can be caused or worsened by obesity, injury, or overuse.
The medical definition of osteoarthritis is: "a degenerative, non-inflammatory joint disease characterized by the loss of articular cartilage, bone remodeling, and the formation of osteophytes (bone spurs). It is often associated with pain, stiffness, and decreased range of motion in the affected joint."
The extracellular matrix (ECM) is a complex network of biomolecules that provides structural and biochemical support to cells in tissues and organs. It is composed of various proteins, glycoproteins, and polysaccharides, such as collagens, elastin, fibronectin, laminin, and proteoglycans. The ECM plays crucial roles in maintaining tissue architecture, regulating cell behavior, and facilitating communication between cells. It provides a scaffold for cell attachment, migration, and differentiation, and helps to maintain the structural integrity of tissues by resisting mechanical stresses. Additionally, the ECM contains various growth factors, cytokines, and chemokines that can influence cellular processes such as proliferation, survival, and differentiation. Overall, the extracellular matrix is essential for the normal functioning of tissues and organs, and its dysregulation can contribute to various pathological conditions, including fibrosis, cancer, and degenerative diseases.
I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.
However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.
I apologize, but "sheep" is not a term that has a medical definition. It is a common animal with the scientific name Ovis aries. If you have any medical or health-related questions, I would be happy to try and help answer those for you.
"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.
Scanning electron microscopy (SEM) is a type of electron microscopy that uses a focused beam of electrons to scan the surface of a sample and produce a high-resolution image. In SEM, a beam of electrons is scanned across the surface of a specimen, and secondary electrons are emitted from the sample due to interactions between the electrons and the atoms in the sample. These secondary electrons are then detected by a detector and used to create an image of the sample's surface topography. SEM can provide detailed images of the surface of a wide range of materials, including metals, polymers, ceramics, and biological samples. It is commonly used in materials science, biology, and electronics for the examination and analysis of surfaces at the micro- and nanoscale.
Fibrocartilage
Fibrocartilage callus
Triangular fibrocartilage
Wrist arthroscopy
Coccyx
Pubic symphysis
Second-harmonic imaging microscopy
HAPLN1
Microfracture surgery
Chondrogenesis
Cartilaginous joint
Medial meniscus
Internal carotid artery
Osteochondritis dissecans
Unhappy triad
Sacroiliac joint
SLAP tear
Glossary of medicine
Distal radius fracture
Temporomandibular joint
Synchondrosis
Degenerative disc disease
Brasilodon
Sternoclavicular joint
Intervertebral disc
Articular cartilage damage
Pelvic girdle pain
James H-C. Wang
Fibroblast
Skeleton
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TFCC13
- In 1981, Palmer and Werner introduced the term triangular fibrocartilage complex (TFCC) to describe the ligamentous and cartilaginous structures that suspend the distal radius and ulnar carpus from the distal ulna (see the image below). (medscape.com)
- Ulnocarpal portion of triangular fibrocartilage complex (TFCC) is composed of discus articularis, ulnolunate ligament (ULL), and ulnotriquetral ligament (UTL). (medscape.com)
- The triangular fibrocartilage complex ( TFCC ) serves as a cushion between the ulnar head and the ulnar carpal bones and also as a major stabilizer of the DRUJ and distal ulna. (medscape.com)
- This entry was posted in Back and Joint Pain and tagged TFCC) , Triangular Fibrocartilage Complex Tears , wrist pain . (sydneyphysioclinic.com.au)
- The New York State workers compensation board has developed these guidelines to help physicians, podiatrists, and other healthcare professionals provide appropriate treatment for Triangular Fibrocartilage Complex (TFCC) Tears. (cortho.org)
- Triangular fibrocartilage complex (TFCC) rips are common wrist injuries affecting the cartilaginous meniscus between the radius and ulna. (cortho.org)
- Diagnostic Studies of Triangular Fibrocartilage Complex (TFCC) Tears X-rays Diagnostic Studies of Triangular Fibrocartilage Complex (TFCC) Tears X-rays are recommended to determine if there are TFCC (triangular fibrocartilage complex) tears. (cortho.org)
- Triangular fibrocartilage complex (TFCC) injuries of the wrist affect the ulnar (little finger) side of the wrist. (jamesseedsmd.com)
- The triangular fibrocartilage complex (TFCC) suspends the ends of the radius and ulna bones over the wrist. (jamesseedsmd.com)
- The entire triangular fibrocartilage complex (TFCC) sits between the ulna and two carpal bones (the lunate and the triquetrum). (jamesseedsmd.com)
- Triangular fibrocartilage complex (TFCC) tears can also occur with degenerative changes. (jamesseedsmd.com)
- A TFCC injury refers to damage sustained by the triangular fibrocartilage complex in the wrist. (mmarmedical.com)
- A TFCC tear is an injury to the triangular fibrocartilage complex found in the wrist. (sportsinjuryclinic.net)
Hyaline4
- In this article, we will take a closer look at the different types of cartilage in anatomy: hyaline, elastic, and fibrocartilage. (medicalcafe.org)
- The pubic symphysis is a secondary cartilaginous joint (a joint made of hyaline cartilage and fibrocartilage) located between the left and right pubic bones near the midline of the body. (healthline.com)
- The pubic symphysis is covered by hyaline cartilage and united by a disc of fibrocartilage . (healthline.com)
- There are three types of cartilage in the body: hyaline, elastic, and fibrocartilage. (lu.se)
Complex18
- Triangular fibrocartilage complex suspends distal radius and ulnar carpus from distal ulna. (medscape.com)
- Reprinted with permission from Palmer AK and Werner FW: The Triangular Fibrocartilage Complex of the Wrist - Anatomy and Function. (medscape.com)
- Triangular fibrocartilage complex provides continuous gliding surface across entire distal face of radius and ulna to allow for flexion-extension and translational movements. (medscape.com)
- Relation of triangular fibrocartilage complex to distal radius and ulnar styloid. (medscape.com)
- Distally, triangular fibrocartilage complex inserts into lunate triquetrum via ulnolunate and ulnotriquetral ligaments. (medscape.com)
- Athletes who put a lot of pressure on the wrist, such as gymnasts, or those playing racquet or stick sports like tennis, baseball, hockey… are also at risk of developing a triangular fibrocartilage complex tear. (sydneyphysioclinic.com.au)
- Degenerative tears of the triangular fibrocartilage complex, are more common in people over 50 years old more likely to suffer with these degenerative complaints if the individual was involved heavily in the above mentioned sports or had a number of previous episodes of falls in their younger years. (sydneyphysioclinic.com.au)
- And as discussed above any history of ongoing symptoms such as 'pain lifting yourself out of a chair, with wrists in extension' often indicates a suspicion of a triangular fibrocartilage complex tear. (sydneyphysioclinic.com.au)
- Anyone seeking specific orthopaedic advice or assistance on Triangular Fibrocartilage Complex Tears should consult his or her general practitioner, sports medicine specialist, orthopaedic surgeon or physiotherapist. (sydneyphysioclinic.com.au)
- The triangular fibrocartilage complex solidly connects the ulnar axis to the volar carpus. (medscape.com)
- Injury to the triangular fibrocartilage complex involves tears of the fibrocartilage articular disc and meniscal homologue. (jamesseedsmd.com)
- The triangular fibrocartilage complex stabilizes the wrist at the distal radioulnar joint. (jamesseedsmd.com)
- Power drill injuries can also cause triangular fibrocartilage complex rupture when the drill binds and the wrist rotates instead of the drill bit. (jamesseedsmd.com)
- Open repair of the ulnar disruption of the triangular fibrocartilage complex with double three-dimensional mattress suturing technique. (qxmd.com)
- Open repair technique of the ulnar disruption of the triangular fibrocartilage complex is described. (qxmd.com)
- This technique is indicated for a fresh or a relatively fresh (less than 1 year after the initial injury) ulnar foveal detachment tear, horizontal tear, and proximal slit tear of the triangular fibrocartilage complex, all of which are accompanied by severe dorsal, palmar, or multidirectional instability of the distal radioulnar joint. (qxmd.com)
- A chronic tear greater than 1 year from initial injury and a fresh triangular fibrocartilage complex tear without distal radioulnar joint instability, such as central slit tear, are excluded from our indications. (qxmd.com)
- A small, 5-mm longitudinal incision at the origin of the radioulnar ligament exposes its fovea detachment and/or the proximal slit tear of the triangular fibrocartilage complex. (qxmd.com)
Cartilage1
- In cases like this, the body will form a scar in the area using a special type of cartilage called fibrocartilage. (wikipedia.org)
Intervertebral fibrocartilage1
- Intervertebral discs, also known as intervertebral fibrocartilage or spinal discs, provide the padding between the vertebrae of the spine. (medicalnewstoday.com)
Elastic2
- C. Elastic fibrocartilage. (medicalcafe.org)
- They have an elastic structure, made of fibrocartilage tissue. (medicalnewstoday.com)
Distally1
- From the ulnar styloid, the triangular fibrocartilage extends distally, receiving contributions from the ulnar collateral ligament, which thickens as the meniscus homologue, inserting onto the lunate, the triquetrum, and the fifth metacarpal. (medscape.com)
Wrist1
- In the 1980s when we were investigating wrist pain in competitive gymnasts, we noticed something strange: In many of these adolescent athletes, the distal radius was short in proportion to the ulna, creating an impingement of the triangular fibrocartilage. (medscape.com)
Ligaments2
- The triangular fibrocartilage and the dorsal and volar ligaments arise from the ulnar aspect of the lunate facet of the radius. (medscape.com)
- The fibrocartilage disc is then reinforced by ligaments, which are bound to the disc itself, and tendons from the obliquus externus, rectus abdominis, and gracilis. (healthline.com)
Degenerative1
- citation needed] Degeneration of fibrocartilage is seen in degenerative disc disease. (wikipedia.org)
20221
- Such development pattern shares an overlapping biological behavior with the growth plate, which is a process of mesenchymal stem cells differentiating into chondrogenic cells and then sequentially into fibrocartilage cells ( Killian, 2022 ). (elifesciences.org)
Bone marrow1
- Defects without repair and defects treated with bone marrow stimulation appeared slightly irregular with fibrocartilage filling. (unboundmedicine.com)
Enthesis5
- Fibrocartilage is the shocking absorbing tissue at the enthesis insertion site and within the adjacent synovio-entheseal complexes. (enthesis.info)
- The extent of the fibrocartilage distribution at the Achilles tendon enthesis organ is shown in the figure below. (enthesis.info)
- Excessive fibrocartilage microdamage in athletes may contribute to enthesis inflammation and pain. (enthesis.info)
- The attachment site of the rotator cuff (RC) is a classic fibrocartilaginous enthesis, which is the junction between bone and tendon with typical characteristics of a fibrocartilage transition zone. (elifesciences.org)
- Currently, the mechanism underlying the growthof the enthesis fibrocartilage is less understood. (elifesciences.org)
Labrum2
- This rim of fibrocartilage is the glenoid labrum. (medscape.com)
- To compensate for this loss of coverage, the labrum (a type of fibrocartilage) becomes hypertrophied and is at risk for tearing. (sciencedaily.com)
Tissue2
- Fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. (wikipedia.org)
- Use of autologous synoviocytes from the affected stifle is an attractive cell source for tissue engineering replacement fibrocartilage. (oregonstate.edu)
Nucleus1
- The disks have a tough, outer layer of fibrocartilage and a soft, jelly-like interior called the nucleus. (msdmanuals.com)
Mixture1
- The fibrocartilage and mixture of connective tissues in group III animals. (vin.com)
Type2
- The extracellular matrix of fibrocartilage is mainly made from type I collagen secreted by chondroblasts. (wikipedia.org)
- The arrowheads show fragmentation and breakage of the fibrocartilage lining F= fissures of deep cracks in fibrocartilage PF= periosteal fibrocartilage which means the type that lines the bone. (enthesis.info)
Inflammation1
- Damage to the fibrocartilage may trigger inflammation and pain in this region. (enthesis.info)
Repair1
- Fibrocartilage repair is generally seen. (vin.com)
Disks1
- Lying between the bones are pads of fibrocartilage called disks, which provide support and flexibility. (medicalnewstoday.com)
Cells1
- However, the diseased state of these cells may impede in vitro fibrocartilage formation. (oregonstate.edu)
Damage3
- The high forces being exerted at the fibrocartilage makes it prone to microscopic damage termed microdamage. (enthesis.info)
- At what age this fibrocartilage damage starts is not clear. (enthesis.info)
- There is very little information on fibrocartilage damage. (enthesis.info)
Normal1
- Fibrocartilage microdamage is very common with normal ageing [1] . (enthesis.info)
Shows2
- The green area shows the extent of shock absorbing fibrocartilage. (enthesis.info)
- This image shows extensive fibrocartilage microdamage. (enthesis.info)