Some movement may occur Ex radioulnar interosseus membrane Gomphosis gomphoses Peg in socket fibrous joint Tooth in its alveolar socket Short periodontal ligament Specialized joints Pegs that fit into sockets Periodontal ligaments hold teeth in place Gingivitis leads to periodontal disease Cartilaginous Joints Synchondroses Joined by hyaline cartilage Little or no movement Some are temporary and are replaced by synostoses Some are permanent Some like costochondral joints develop into synovial joints Ex Epiphyseal plates sternocostal sphenooccipital Symphyses Fibrocartilage uniting two bones Slightly movable Ex symphysis pubis between the manubrium sternum and the body of the sternum intervertebral disks Synovial Joints Articular cartilage hyaline provides smooth surface Joint cavity synovial encloses articular surfaces Capsule Fibrous capsule dense irregular connective tissue continuous with fibrous layer of the periosteum Portions may thicken to form ligaments Synovial membrane and fluid membrane lines inside of joint capsule except at actual articulation of articular cartilages Synovial fluid reduces friction by lubricating the joint and absorbing shocks It also supplies oxygen and nutrients to the cartilage while removing carbon dioxide and metabolic wastes Synovial fluid complex mixture of polysaccharides proteins fat and cells Hyaluronic acid slippery No blood vessels or nerves in articular cartilages nutrients from nearby blood vessels and synovial fluid Nerves in capsule help brain know position of joints proprioception Types Uniaxial occurring around one axis Biaxial occurring around two axes at right angles to each other Multiaxial occurring around several axes Plane or gliding joints Air hockey Uniaxial some rotation possible but limited by surrounding structures Ex intervertebral intercarpal acromioclavicular carpometacarpal costovertebral intertarsal sacroiliac tarsometatarsal Saddle joints Cowboy Biaxial Ex thumb carpometacarpal pollicis intercarpal sternoclavicular Hinge joints Door Frame Uniaxial Convex cylinder in one bone corresponding concavity in the other Ex elbow ankle interphalangeal Pivot joints Basketball pivot foot Uniaxial Rotation around a single axis Cylindrical bony process rotating within a circle of bone and ligament Ex articulation between dens of axis and atlas atlantoaxial proximal radioulnar distal radioulnar Ball and socket Tether ball Multiaxial Stability is reduced mobility is increased compared to hip Flexion extension abduction adduction rotation circumduction Ex shoulder and hip Bobsled Modified ball and socket articular surfaces are ellipsoid Biaxial Ex atlantooccipital joints Ellipsoid Condyloid Flexion and Extension Flexion movement of a body part anterior to the coronal plane Extension movement of a body part posterior to the coronal plane Exceptions to the definition Plantar flexion standing on the toes Dorsiflexion foot lifted toward the shin Abduction and Adduction Abduction movement away from the median plane Adduction movement toward the median plane Circular Movement Rotation turning of a structure on its long axis Ex rotation of the head humerus entire body Medial and lateral rotation Ex rotation of the arm Pronation Supination refer to unique rotation of the forearm Pronation palm faces posteriorly Supination palm faces anteriorly Circumduction Combination of flexion extension abduction adduction internal and external rotation Appendage describes a cone Protraction and Retraction Protraction gliding motion anteriorly Retraction moves structure back to anatomic position or even further posteriorly Ex scapulae and mandibles Excursion Lateral moving mandible to the right or left of midline Medial return the mandible to the midline Opposition and Reposition Opposition movement of thumb and little finger toward each other Reposition return to anatomical position Inversion and Eversion Inversion turning the ankle so the plantar surface of foot faces medially Eversion turning the ankle so the plantar surface of foot faces laterally Shoulder Glenohumeral Joint Ball and socket joint formed by the head of the humerus and the scapula Glenoid labrum rim of fibrocartilage built up around glenoid cavity joint capsule attachment Bursae subacromial and subscapular Rotator cuff four muscles that along with ligaments give stability to the joint Tendon of biceps brachii passes through the joint capsule Elbow Joint Compound hinge joint Humeroulnar joint Humeroradial joint Proximal radioulnar joint Shape of trochlear notch and trochlea limit movement to extension and flexion Rounded head of radius allows pronation and supination Hip Coxal Joint Ball and socket with acetabulum More stable but less mobile than shoulder joint Flexion extension abduction adduction rotation circumduction Extremely strong joint capsule reinforced by ligaments that bears much of the body weight while standing Ligament of head of femur round ligament of femur often bears nutrient artery Knee Tibiofermoral Joint Modified hinge joint Largest and most complex joint of the body Babies are born without knee caps patellas Anterior cruciate ligament ACL the ligament located in the center of the knee that controls rotation and forward movement of the tibia shin bone Posterior cruciate ligament PCL the ligament located in the center of the knee that controls backward movement of the tibia shin bone Cruciate cross shaped Medial collateral ligament MCL the ligament that gives stability to the inner knee protects knee against valgus force lateral to medial Lateral collateral ligament LCL protects knee against varus force medial to lateral the ligament that gives stability to the outer knee Menisci Medial meniscus MC C Shaped Lateral meniscus O shaped Highly modified hinge joint Dorsiflexion plantar flexion limited inversion and eversion Lateral and medial thickening of articular capsule to prevent side to side movement Ankle Talocrural Joint Articles Joint Replacement People who need their first knee replacement these days tend to be heavier than candidates for prosthetics in past decades Obese persons with a BMI of 35kg m2 and more are particular risk candidates for reoperations and infections 2x of revisions 2x deep infections 2x knee replacements Effect higher in men more than women Out of 1 000 persons needing total knee replacement more than 90 percent of them were overweight or obese Greater bleeding or longer surgery duration can occur within this patient group Patient