Joints Lecture Notes PDF

Joints By Bhavesh K. Sharma  JOINTS  DEFINITION  INTRODUCTION  CLASSIFICATION- ◦ IMMOVABLE ◦ MOVABLE  BLOOD SUPPLY  NERVE SUPPLY  LYMPHATIC DRAINAGE  CLINICAL NOTES Definition Definition  Joint is a junction between two or more bones or c...

Joints By Bhavesh K. Sharma  JOINTS  DEFINITION  INTRODUCTION  CLASSIFICATION- ◦ IMMOVABLE ◦ MOVABLE  BLOOD SUPPLY  NERVE SUPPLY  LYMPHATIC DRAINAGE  CLINICAL NOTES Definition Definition  Joint is a junction between two or more bones or cartilages  Related term: arthron  Long bones articulate by their ends  Flat bones by their margins  Short and irregular bones by surfaces  SAGITTAL TEMPORO-MANDIBULAR JOINT SUTURE STERNO-CLAVICULAR JOINT SHOULDER JOINT 1ST CHONDRO-STERNAL JOINT ELBOW JOINT INTERVERTEBRAL JOINT INTERCARPAL JOINT WRIST JOINT METACARPAL- PHALANGEAL JOINT HIP JOINT PUBIC SYMPHYSIS KNEE JOINT INFERIOR TIBIO-FIBULAR JOIN ANKLE JOINT Classification joints immovable Movable cartilagi fibrous 1. synovial nous Primary 1.Sutur cartilag es- 1. Plane inous 5types 2.Uniaxial- 3 joint 2. types 2. Syndes 3. Biaxial- 2 Second moses types ary 3.gomp 4. multiaxial cartilag hosis inous joint  Immovable Immovable joints joints  A. Fibrous joints  In these joints bones are united by fibrous tissue.  3 types: A. SUTURE- 1.serrate suture 2.denticulate suture 3.squamous suture 4.plane suture 5.wedge in groove suture B.SYNDESMOSES C. GOMPHOSIS A.SUTURES  Most of the joints of the skull are suture joints.  Here, ligament or suture membrane connect the periosteum  Types: 5 1. SERRATE SUTURE : The edge of bones present saw tooth appearance. e.g.- sagittal suture of the skull 2. DENTICULATE SUTURE : The margins present teeth like appearance. Tips are broader than the roots. e.g. lambdoid suture  3. SQUAMOUS SUTURE: Here the edges of bone are united by overlapping. E.g.-between parietal bone and squamous part of temporal bone. BONE SUTURAL MEMBRANE PERIOSTEUM 4. PLANE SUTURE: The borders are plane and united by sutural ligament. E.g. articulation between palatine process of two maxillae. PERIOSTEUM BONE BONE SUTURAL MEMBRANE 5. WEDGE AND GROOVE SUTURE- The edge of one bone fits in the groove of the other bone. E.g. -between the rostrum of sphenoid and the upper margin of vomer. ROSTRUM OF SPHENOID VOMER B. SYNDESMOSES  Bones forming the joint lie some distance apart , surfaces are united by interosseus ligaments.  Slight movement is permissible ◦ E.g. inferior tibiofibular joint ◦ middle radio ulnar joint,  C. GOMPHOSES ◦ Peg in socket joint ◦ The root of teeth fit in the socket of the jaw & are united by fibrous tissue ◦ Only found in teeth.  CARTILAGINOUS JOINT  1. Primary cartilaginous joint( synchondroses) ◦ Bones are united by a plate of hyaline cartilage ◦ replaced completely by bone when growh of diaphysis is complete ◦ no movement is possible ◦ Primarily designed for bone growth e.g. joint between epiphysis and diaphysis of a growing bone  2. Secondary cartilagionus joint ( symphyses)  These joints are permanent and persist throughout the life.  Here, joint surface is covered by hyaline cartilage and united by fibro-cartilage.  Occupy median plane of body.  E.g. pubic symphysis  Intervertebral joint  Synovial joints-due to presence of synovial fluid (like egg albumin)  Diarthroses(Synovial Mobile Joints):- joints  Most common joints in body  movable joints Components of synovial joint:- 1. Articular capsule- Outer- fibrous capsule Inner- synovial membrane 2. Joint cavity 3. Cavity is filled with synovial fluid. 4. articular cartilage 5. Ligaments 6. Articular disc or meniscus- in some joints eamcetzoology.blogspot.com/ 2008/08/joints- images_6908.html  1. Articular capsule-  2 Layers- fibrous capsule Synovial membrane  Outer -Fibrous capsule is sensitive to stretches and change in position  Pierced by blood vessel and nerves.  Importance:  As the capsule is sensitive to stretch, it protects the joint from any sprain.  Binds the articulating bones together.  Supports the synovial membrane on the inner surface. eamcetzoology.blogspot.com/ Articular capsule 2. Inner layer – synovial membrane  Vascular membrane lining whole of the interior the joint except the articular surfaces.  Highly vascular and cellular  Connective tissue membrane Importance:  The membrane secretes a synovial fluid.  Liberates hyaluronic acid which maintains viscosity of fluid.  Removes particulate matters. Synovial fluid:  It nourishes the articular cartilage  Lubricates the joint surfaces  3. Articular cartilage  Characteristics:  Hyaline in structure  Avascular, non-nervous and elastic  It has no covering of perichondrium so, once damaged, can not replaced by hyaline tissue, it’s replaced by fibrous tissue.  It is lubricated with synovial fluid  Importance:  the cartilage provides slippery surfaces for free movements, like ‘ice on ice’.  4. Ligament  Ligaments are fibrous band made up of collagen fibers  connect the adjacent bones.  A. True ligaments : thickening of the fibrous capsule  B. Accessory ligaments which may be intracapsular or extracapsular.  Maintain the stability of the joint eamcetzoology.blogspot.com/ 2008/08/joints-images_6908.html  5. Articular disc or menisci-  Joint cavity is divided completely or incompletely into two compartments  Made up of fibro-cartilage  Articular disc is attached at the periphery to the fibrous capsule. Importance of articular disc: 1. Helps in lubrication of a joint 2. Prevents wear & tear of the articular cartilage 3. Modify the shape of articulating surfaces so, the two bones of different shapes can fit more tightly. 4. Provides different movement into upper and lower compartments. SYNOVIAL JOINT  Classification:  According to the number of bones uniting 1. SIMPLE- Joint is between 2 bones E.g. interphalangeal joints 2. COMPOUND- more than 2 bones uniting E.g. wrist joint, ankle joint 3. COMPLEX ( Atypical synovial joint ) – joint cavity is divided by an articular disc or menisci into two compartments E.g. knee joint, temporomandibular joint Classification according to axis /plane of movement 1. uniaxial synovial joint—one plane ◦ Hinge joint(elbow,ankle,interphalangeal) ◦ Pivot joint-vertical axis only rotation possible(superior radioulnar joint) ◦ Condylar joint ( modified hinge joint)-with flexion extension slight rotation is also possible(TMJ,knee) 2. Biaxial synovial joint- ◦ Ellipsoid –flexion extension along transverse axis and abduction adduction along A-P axis(radio carpal joint). ◦ Saddle –flexion extension abduction adduction with some rotation eg first carpometacarpal joint. 3. poly axial synovial joint-movements in three planes..here all movements are possible.(shoulder joint) 1. PLANE SYNOVIAL JOINT  Articular surfaces are flat  Provide gliding movements  E.g. intercarpal, intermetatarsal  Intercarpometacarpal  Chondrosternal except 1st  Interchondral  Costoverterbral  acromioclavicular 2. UNIAXIAL JOINT  2. a. Hinge variety  Moves around transverse axis  One articular surface is convex and other is curved  E.g. interphalangeal joints Elbow joint knee joint 2.B. PIVOT VARIETY  Articular surfaces comprise a central bony pivot (peg) surrounded by an osteoligamentous ring  Movements are permitted in one plane around vertical axis  E.g. superior and inferior radioulnar joint Median atlanto axial joint 2.C. Condylar variety (modified hinge joint)  Moves mainly around a transverse axis and partly around a vertical axis  Each bone consist of two distinct articular surfaces known as condyles.  E.g. knee joint  temporo mandibular joint 3. BIAXIAL SYNOVIAL JOINT  These joints have 2 degree freedom of movements.  3.a. ELLIPSOID VARIETY  3.B. SADDLE VARIETY  3.A. ELLIPSOID VARIETY:  one articular surface is convex and elliptical ( oval ) in outline. The other articular surface is concave and reciprocally curved.  Movement takes place around transverse and anterio-posterior axes.  Flexion, extension, adduction, abduction, circumduction  E.g. wrist joint, atlanto-occipital joint , metatarsophalangeal joints etc. 3. B. SADDLE VARIETY  Articular surfaces are saddle shaped and the other bone has the reciprocally concavo- convex surface.  E.g. sternoclavicular, calcaneo-cuboid, between femur and patella, 1st carpo-metacarpal 4. POLYAXIAL JOINT  Known as ball and socket joint  Possess 3 degree freedom of movements  Articular surfaces include a globular head fitting into cup shaped socket -movement take place around transverse, antero-posterior, vertical axis. e.g.- shoulder joint, & hip joint, talo-calcaneo-navicular joint. Factors maintaining stability of joint:- 1. Muscles: :- tone of different muscle groups maintain the joint stability, important factor e.g. shoulder joint 2. Shape of articulating surfaces of bones: e.g. hip joint, head of femur is completely received by acetabular socket 3. Ligaments: permits desirable movements and prevents undesirable movements. Blood supply ◦ Arterial branches from several different arteries merge around a joint, & form a rich plexus before penetrating the articular capsule ◦ Articular cartilage is avascular & gets nutrition by diffusion. Nerve supply  Capsule and ligaments possess a rich nerve supply.  3 different types-  1. sensory nerves- convey pain sensation  2. sensory nerve conveying proprioseptive sensations.  3. autonomic nerves- vasomotor, vasosensory ∗ therefore, the joint pain is associated with, nausea, vomiting, slowing of pulse and blood pressure  Hilton’s law  The law states that the nerves supplying a joint, also suppy muscles regulating the movements of the joint & the skin over the joint  This mechanism of innervation helps to protect the joint.  Lymphatic drainage:  Form a plexus in the synovial membrane  Clinical anatomy: Dislocation of the joint  This is a condition in which the articular surfaces of the joint are abnormally displaced, so one surface loses its contact completely from the other.  If partial contact is still retained, it is called subluxation. 2. Osteoarthritis Degenerative joint disease - aging, wear & tear - Affects large weight bearing joints - Patient feels lots of pain due to rubbing of bones during movements.  4. Arthroscopy- examination of joint - By an instrument size of a pencil - Requires small incisions only - Diagnostic and theraputic purpose - remove torn knee cartilage GOOD DAY