It has been suggested that Multiaxial joint be merged into this article. (Discuss) Proposed since December 2023.
A synovial joint, also known as diarthrosis, joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulating surfaces. This joint unites long bones and permits free bone movement and greater mobility.[1] The synovial cavity/joint is filled with synovial fluid. The joint capsule is made up of an outer layer of fibrous membrane, which keeps the bones together structurally, and an inner layer, the synovial membrane, which seals in the synovial fluid.
They are the most common and most movable type of joint in the body of a mammal. As with most other joints, synovial joints achieve movement at the point of contact of the articulating bones.
Synovial cavity: all diarthroses have the characteristic space between the bones that is filled with synovial fluid.
Joint capsule: the fibrous capsule, continuous with the periosteum of articulating bones, surrounds the diarthrosis and unites the articulating bones; the joint capsule consists of two layers - (1) the outer fibrous membrane that may contain ligaments and (2) the inner synovial membrane that secretes the lubricating, shock absorbing, and joint-nourishing synovial fluid; the joint capsule is highly innervated, but without blood and lymph vessels, and receives nutrition from the surrounding blood supply via either diffusion (a slow process) or by convection, a far more efficient process achieved through exercise.
Articular cartilage: the bones of a synovial joint are covered by this layer of hyaline cartilage that lines the epiphyses of joint end of bone with a smooth, slippery surface that does not bind them together; articular cartilage functions to absorb shock and reduce friction during movement.
Many, but not all, synovial joints also contain additional structures:[2]
Accessory ligaments (extracapsular and intracapsular) - the fibers of some fibrous membranes are arranged in parallel bundles of dense regular connective tissue that are highly adapted for resisting strains to prevent extreme movements that may damage the articulation[citation needed]
Bursae - saclike structures that are situated strategically to alleviate friction in some joints (shoulder and knee) that are filled with fluid that is similar to synovial fluid[3][page needed]
The bone surrounding the joint on the proximal side is sometimes called the plafond, especially in the talocrural joint. A damage to this occurs in a Gosselin fracture.
Blood supplyedit
The blood supply of a synovial joint is derived from the arteries sharing in the anastomosis around the joint.
Typesedit
There are seven types of synovial joints.[4] Some are relatively immobile, but are more stable. Others have multiple degrees of freedom, but at the expense of greater risk of injury.[4] In ascending order of mobility, they are:
A condyloid joint is a modified ball and socket joint that allows primary movement within two perpendicular axes, passive or secondary movement may occur on a third axes. Some classifications make a distinction between condyloid and ellipsoid joints;[5][6] these joints allow flexion, extension, abduction, and adduction movements (circumduction).
Saddle joints, where the two surfaces are reciprocally concave/convex in shape, which resemble a saddle, permit the same movements as the condyloid joints but allows greater movement.
rotation: a circular movement around a fixed point
Clinical significanceedit
The joint space equals the distance between the involved bones of the joint. A joint space narrowing is a sign of either (or both) osteoarthritis and inflammatory degeneration.[9] The normal joint space is at least 2 mm in the hip (at the superior acetabulum),[10] at least 3 mm in the knee,[11] and 4–5 mm in the shoulder joint.[12] For the temporomandibular joint, a joint space of between 1.5 and 4 mm is regarded as normal.[13] Joint space narrowing is therefore a component of several radiographic classifications of osteoarthritis.
In rheumatoid arthritis, the clinical manifestations are primarily synovial inflammation and joint damage. The fibroblast-like synoviocytes, highly specialized mesenchymal cells found in the synovial membrane, have an active and prominent role in the pathogenic processes in the rheumatic joints.[14] Therapies that target these cells are emerging as promising therapeutic tools, raising hope for future applications in rheumatoid arthritis.[14]
^Tortora & Derrickson () Principles of Anatomy & Physiology (12th ed.). Wiley & Sons
^ abUmich (2010). . Learning Modules - Medical Gross Anatomy. University of Michigan Medical School. Archived from the original on 2011-11-22.
^Rogers, Kara (2010) Bone and Muscle: Structure, Force, and Motion p.157
^Sharkey, John (2008) The Concise Book of Neuromuscular Therapy p.33
^Moini (2011) Introduction to Pathology for the Physical Therapist Assistant pp.231-2
^Bruce Abernethy (2005) The Biophysical Foundations Of Human Movement pp.23, 331
^Jacobson, Jon A.; Girish, Gandikota; Jiang, Yebin; Sabb, Brian J. (2008). "Radiographic Evaluation of Arthritis: Degenerative Joint Disease and Variations". Radiology. 248 (3): 737–747. doi:10.1148/radiol.2483062112. ISSN 0033-8419. PMID 18710973.
^Lequesne, M (2004). "The normal hip joint space: variations in width, shape, and architecture on 223 pelvic radiographs". Annals of the Rheumatic Diseases. 63 (9): 1145–1151. doi:10.1136/ard.2003.018424. ISSN 0003-4967. PMC1755132. PMID 15308525.
^Roland W. Moskowitz (2007). Osteoarthritis: Diagnosis and Medical/surgical Management, LWW Doody's all reviewed collection. Lippincott Williams & Wilkins. p. 6. ISBN9780781767071.
^"Glenohumeral joint space". radref.org., in turn citing: Petersson, Claes J.; Redlund-Johnell, Inga (2009). "Joint Space in Normal Gleno-Humeral Radiographs". Acta Orthopaedica Scandinavica. 54 (2): 274–276. doi:10.3109/17453678308996569. ISSN 0001-6470. PMID 6846006.
^Massilla Mani, F.; Sivasubramanian, S. Satha (2016). "A study of temporomandibular joint osteoarthritis using computed tomographic imaging". Biomedical Journal. 39 (3): 201–206. doi:10.1016/j.bj.2016.06.003. ISSN 2319-4170. PMC6138784. PMID 27621122.
^ abNygaard, Gyrid; Firestein, Gary S. (2020). "Restoring synovial homeostasis in rheumatoid arthritis by targeting fibroblast-like synoviocytes". Nature Reviews Rheumatology. 16 (6): 316–333. doi:10.1038/s41584-020-0413-5. PMC7987137. PMID 32393826.
Wikimedia Commons has media related to Synovial joints.
January 01, 1970
synovial, joint, been, suggested, that, multiaxial, joint, merged, into, this, article, discuss, proposed, since, december, 2023, synovial, joint, also, known, diarthrosis, joins, bones, cartilage, with, fibrous, joint, capsule, that, continuous, with, periost. It has been suggested that Multiaxial joint be merged into this article Discuss Proposed since December 2023 A synovial joint also known as diarthrosis joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones constitutes the outer boundary of a synovial cavity and surrounds the bones articulating surfaces This joint unites long bones and permits free bone movement and greater mobility 1 The synovial cavity joint is filled with synovial fluid The joint capsule is made up of an outer layer of fibrous membrane which keeps the bones together structurally and an inner layer the synovial membrane which seals in the synovial fluid Synovial jointStructure of synovial jointTypes of synovial joints Clockwise from top right ball and socket joint condyloid joint plane joint saddle joint hinge joint and pivot joint DetailsIdentifiersLatinjunctura synovialisTA98A03 0 00 020TA21533FMA7501Anatomical terminology edit on Wikidata They are the most common and most movable type of joint in the body of a mammal As with most other joints synovial joints achieve movement at the point of contact of the articulating bones Contents 1 Structure 1 1 Blood supply 1 2 Types 2 Function 3 Clinical significance 4 ReferencesStructure editSynovial joints contain the following structures Synovial cavity all diarthroses have the characteristic space between the bones that is filled with synovial fluid Joint capsule the fibrous capsule continuous with the periosteum of articulating bones surrounds the diarthrosis and unites the articulating bones the joint capsule consists of two layers 1 the outer fibrous membrane that may contain ligaments and 2 the inner synovial membrane that secretes the lubricating shock absorbing and joint nourishing synovial fluid the joint capsule is highly innervated but without blood and lymph vessels and receives nutrition from the surrounding blood supply via either diffusion a slow process or by convection a far more efficient process achieved through exercise Articular cartilage the bones of a synovial joint are covered by this layer of hyaline cartilage that lines the epiphyses of joint end of bone with a smooth slippery surface that does not bind them together articular cartilage functions to absorb shock and reduce friction during movement Many but not all synovial joints also contain additional structures 2 Articular discs or menisci the fibrocartilage pads between opposing surfaces in a joint Articular fat pads adipose tissue pads that protect the articular cartilage as seen in the infrapatellar fat pad in the knee Tendons 2 cords of dense regular connective tissue composed of parallel bundles of collagen fibers Accessory ligaments extracapsular and intracapsular the fibers of some fibrous membranes are arranged in parallel bundles of dense regular connective tissue that are highly adapted for resisting strains to prevent extreme movements that may damage the articulation citation needed Bursae saclike structures that are situated strategically to alleviate friction in some joints shoulder and knee that are filled with fluid that is similar to synovial fluid 3 page needed The bone surrounding the joint on the proximal side is sometimes called the plafond especially in the talocrural joint A damage to this occurs in a Gosselin fracture Blood supply edit The blood supply of a synovial joint is derived from the arteries sharing in the anastomosis around the joint Types edit There are seven types of synovial joints 4 Some are relatively immobile but are more stable Others have multiple degrees of freedom but at the expense of greater risk of injury 4 In ascending order of mobility they are Name Example Description Plane joints or gliding joint carpals of the wrist acromioclavicular joint These joints allow only gliding or sliding movements are multi axial such as the articulation between vertebrae Hinge joints elbow between the humerus and the ulna These joints act as a door hinge does allowing flexion and extension in just one plane i e uniaxial Pivot joints atlanto axial joint proximal radioulnar joint and distal radioulnar joint One bone rotates about another Condyloid joints or ellipsoidal joints wrist joint radiocarpal joint A condyloid joint is a modified ball and socket joint that allows primary movement within two perpendicular axes passive or secondary movement may occur on a third axes Some classifications make a distinction between condyloid and ellipsoid joints 5 6 these joints allow flexion extension abduction and adduction movements circumduction Saddle joints Carpometacarpal or trapeziometacarpal joint of thumb between the metacarpal and carpal trapezium sternoclavicular joint Saddle joints where the two surfaces are reciprocally concave convex in shape which resemble a saddle permit the same movements as the condyloid joints but allows greater movement Ball and socket joints universal Joint shoulder glenohumeral and hip joints These allow for all movements except gliding Compound joints 7 8 bicondyloid joints 2 knee joint condylar joint condyles of femur join with condyles of tibia and saddle joint lower end of femur joins with patella Function editMain article Anatomical terms of motion The movements possible with synovial joints are abduction movement away from the mid line of the body adduction movement toward the mid line of the body extension straightening limbs at a joint flexion bending the limbs at a joint rotation a circular movement around a fixed pointClinical significance editThe joint space equals the distance between the involved bones of the joint A joint space narrowing is a sign of either or both osteoarthritis and inflammatory degeneration 9 The normal joint space is at least 2 mm in the hip at the superior acetabulum 10 at least 3 mm in the knee 11 and 4 5 mm in the shoulder joint 12 For the temporomandibular joint a joint space of between 1 5 and 4 mm is regarded as normal 13 Joint space narrowing is therefore a component of several radiographic classifications of osteoarthritis In rheumatoid arthritis the clinical manifestations are primarily synovial inflammation and joint damage The fibroblast like synoviocytes highly specialized mesenchymal cells found in the synovial membrane have an active and prominent role in the pathogenic processes in the rheumatic joints 14 Therapies that target these cells are emerging as promising therapeutic tools raising hope for future applications in rheumatoid arthritis 14 References edit The Musculoskeletal System In Dutton M eds Dutton s Orthopaedic Examination Evaluation and Intervention 5e McGraw Hill Accessed January 25 2021 https accessphysiotherapy mhmedical com libaccess lib mcmaster ca content aspx bookid 2707 amp sectionid 224662311 a b c Drake Richard L Vogl Wayne Mitchell Adam W M Gray Henry 2015 Skeletal system Gray s Anatomy for Students 3rd ed p 20 ISBN 978 0 7020 5131 9 OCLC 881508489 Tortora amp Derrickson Principles of Anatomy amp Physiology 12th ed Wiley amp Sons a b Umich 2010 Introduction to Joints Learning Modules Medical Gross Anatomy University of Michigan Medical School Archived from the original on 2011 11 22 Rogers Kara 2010 Bone and Muscle Structure Force and Motion p 157 Sharkey John 2008 The Concise Book of Neuromuscular Therapy p 33 Moini 2011 Introduction to Pathology for the Physical Therapist Assistant pp 231 2 Bruce Abernethy 2005 The Biophysical Foundations Of Human Movement pp 23 331 Jacobson Jon A Girish Gandikota Jiang Yebin Sabb Brian J 2008 Radiographic Evaluation of Arthritis Degenerative Joint Disease and Variations Radiology 248 3 737 747 doi 10 1148 radiol 2483062112 ISSN 0033 8419 PMID 18710973 Lequesne M 2004 The normal hip joint space variations in width shape and architecture on 223 pelvic radiographs Annals of the Rheumatic Diseases 63 9 1145 1151 doi 10 1136 ard 2003 018424 ISSN 0003 4967 PMC 1755132 PMID 15308525 Roland W Moskowitz 2007 Osteoarthritis Diagnosis and Medical surgical Management LWW Doody s all reviewed collection Lippincott Williams amp Wilkins p 6 ISBN 9780781767071 Glenohumeral joint space radref org in turn citing Petersson Claes J Redlund Johnell Inga 2009 Joint Space in Normal Gleno Humeral Radiographs Acta Orthopaedica Scandinavica 54 2 274 276 doi 10 3109 17453678308996569 ISSN 0001 6470 PMID 6846006 Massilla Mani F Sivasubramanian S Satha 2016 A study of temporomandibular joint osteoarthritis using computed tomographic imaging Biomedical Journal 39 3 201 206 doi 10 1016 j bj 2016 06 003 ISSN 2319 4170 PMC 6138784 PMID 27621122 a b Nygaard Gyrid Firestein Gary S 2020 Restoring synovial homeostasis in rheumatoid arthritis by targeting fibroblast like synoviocytes Nature Reviews Rheumatology 16 6 316 333 doi 10 1038 s41584 020 0413 5 PMC 7987137 PMID 32393826 nbsp Wikimedia Commons has media related to Synovial joints Retrieved from https en wikipedia org w index php title Synovial joint amp oldid 1211315965, wikipedia, 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