GAP - Topic 9 - Intro to Arthrology & Syndesmology PDF

Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology TOPIC #9 – INTRODUCTION TO ARTHROLOGY & SYNDESMOLOGY Clinical Orientated Anatomy ARTHROLOGY • • Arthrology: the study of joints. Articulation: joining of bones (= JOINT). o A joint is an articulation betwee...

Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology TOPIC #9 – INTRODUCTION TO ARTHROLOGY & SYNDESMOLOGY Clinical Orientated Anatomy ARTHROLOGY • • Arthrology: the study of joints. Articulation: joining of bones (= JOINT). o A joint is an articulation between 2 bones. Often there is movement produced at a joint o Movement produced at a joint is determined by the shape of the bony surfaces involved ▪ Concave versus convex JOINT CLASSIFICATION ➢ The articular system consists of joints (articulations) and their associated bones and ligaments. ➢ Joints are classified by FUNCTION and STRUCTURE FUNCTIONAL CLASSIFICATION • • Based on how much movement is produced at the joint There are 3 types: 1. Synarthrodial – no or very limited movement 2. Amphiarthrodial – slight movement 3. Diarthrodial – freely moveable STRUCTURAL CLASSIFICATION • • Based on the material holding the joint together There are 3 types with further subclassifications in each 1. Fibrous – Joint is held together by fibrous connective tissue 2. Cartilaginous – Joint held together by cartilage (hyaline or fibrocartilage) 3. Synovial – Many structures involved in holding the joint together 1. FIBROUS JOINTS ➢ The bones in these articulations are united by fibrous tissue. ➢ This joint is (most often) functionally classified as a synarthrosis joint. ➢ There are 3 types of fibrous joints: 1. Suture 2. Syndesmosis 3. Gomphosis Page 1 of 8 Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology SUTURE • • These bones are held together by several layers of strong fibrous connective tissue. The union of the articulating surfaces is extremely tight and there is NO movement between the bones therefore functionally classified as synarthrodial o Sutures occur only in the skull SYNDESMOSIS • • These bones are united by a sheet of fibrous tissue. At a syndesmostic joint, slight to considerable movement can be achieved therefore it is functionally classified as amphiarthrodial o Interosseous membranes between the radius/ulna and the tibia/fibula are examples of this joint GOMPHOSIS • The joint between a tooth and its socket (alveolus), very little movement, therefore it is functionally classified as a synarthrodial joint o The periodontal ligament firmly anchors the tooth and is an example of this joint. Page 2 of 8 Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology 2. CARTILAGINOUS JOINTS ➢ The bones in these articulations are united by cartilaginous tissue (hyaline or fibrocartilage). ➢ This joint is functionally classified as a synarthrodial/amphiarthrodial joints. ➢ There are 2 types of cartilaginous joints: 1. Synchondroses 2. Symphyses SYNCHONDROSIS • • • • • This is a Primary Cartilaginous Joint Bones are connected by hyaline cartilage (found in joints, and immature skeleton) They provide sites for bone growth and contribute to skeletal flexibility. After bone growth has stopped, these joints become ossified and immobile, therefore they are considered to be temporary joints. Functionally classified as synarthrodial o The epiphyseal plates of long bones and the manubriosternal joints are examples of this joint. SYMPHYSIS • • • This is a Secondary Cartilaginous Joint Bones are joined by fibrocartilage (rougher + thicker type cartilage that is compressible and resilient and thus acts as a shock absorber) Strong slightly movable joints, functionally classified as amphiarthrodial joints o Examples include: IVD between the vertebrae, pubic symphysis Page 3 of 8 Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology 3. SYNOVIAL JOINTS ➢ These bones are separated by a fluid-containing joint cavity which allows for substantial movement. ➢ They are therefore functionally classified as diarthrodial. ➢ Most joints of the body are of this structural class Basic Components/ Special features of a Synovial Joint • • • • • • Synovial Membrane – Composed of connective tissue, lines the capsule internally and covers all internal joint surfaces that are not covered by hyaline cartilage Synovial Cavity – Unique to synovial joints, the cavity is a space that is filled with synovial fluid Synovial Fluid – A small amount of slippery fluid that occupies the free space within the capsule. Very viscous texture (egg whites). Provides lubrication for the hyaline cartilage to move on each other Articular Cartilage (Hyaline) – Hyaline cartilage covers the opposing bone surfaces. Provides cushion for compression and smooth surfaces for gliding over one another Joint Capsule – The joint cavity is enclosed by a double layered capsule. The external layer is a tough, flexible fibrous capsule that is continuous with the periosteum of the bone Accessory Ligaments TYPES OF SYNOVIAL JOINTS: 1. 2. 3. 4. 5. 6. Ball and Socket Hinge Pivot Saddle Condyloid Gliding (Planar) Page 4 of 8 Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology BALL AND SOCKET JOINTS • • A spherical surface fitting into a bowl-shaped socket (i.e. Glenohumeral joint (shoulder joint)) Allows for 3 degrees of freedom: Tri-axial movement working in all three planes and axes. o Flexion/extension o Adduction/abduction o Rotation HINGE JOINTS • • • Similar to a door hinge Cylindrical surface fitting into a cylindrical groove (i.e. Elbow joint) Allows for 1 degree of freedom: Uni-axial movement working in only one plane and axis o Flexion/extension PIVOT JOINTS • • A projection fitting into a ring (the ring is usually formed by a ligament) (i.e. Articulation between proximal radius and ulna) Allows for 1 degree of freedom: Uni-axial movement working in only one plane and axis o Rotation Page 5 of 8 Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology SADDLE JOINTS • • The opposing surfaces are reciprocally concave-convex. o i.e. 1st carpometacarpal joint Allows for 2 degrees of freedom: Bi-axial movement working in two planes and axes o Flexion/extension o Adduction/abduction CONDYLOID JOINTS • • An oval shaped projection fitting into an elliptical hole o i.e. Wrist joint Allows for 2 degrees of freedom: Bi-axial movement working through two planes and axes o Flexion/extension o Adduction/abduction PLANAR JOINTS • • • 2 relatively flat surfaces articulating together (opposing surfaces are flat or slightly curved) o i.e. Tarsal bones Allows gliding and sliding motions Has 1 degree of freedom: (only moves in 1 plane therefore uniaxial movement) o Movement is in whichever plane the articular surfaces rest ADDITIONAL FEATURES FOUND AT SYNOVIAL JOINTS ➢ Intra-articular discs – These are fibrocartilaginous discs found at joints to increase the congruency of the joint (i.e. at the TMJ, distal radio-ulnar joint and sternoclavicular joint) ➢ Menisci – Fibrocartilaginous disc found between the femur and tibia to increase congruency of the joint ➢ Bursa – These are closed fluid filled sacs with serous membranes and function to decrease friction between the muscles, tendons and bones. o There are 2 types: 1. Communicating: extension of the joint capsule. 2. Non-communicating: completely separate from the joint capsule ➢ Tendon Sheath – This sheath surrounds and covers the tendon, it allows for movement to occur smoothly with the tendon ➢ Accessory/Articular Ligaments – ligaments that help support the joint Page 6 of 8 Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology SYNDESMOLOGY – LIGAMENTS • • • Syndesmology: the study of ligaments A ligament is a band of fibrosis connective tissue that connects bone to bone Ligaments play a large role in the articular system and serve to support and strengthen joints TYPES OF LIGAMENTS ➢ Joints are reinforced by articular/accessory ligaments. Synovial joints in particular are usually reinforced by these ligaments ➢ There are 3 types: 1. Intrinsic: Considered part of the joint capsule, blends in with the joint capsule and thickens the joint capsule ▪ i.e. Medial Collateral Ligament of the knee 2. Extrinsic (aka Extracapsular): Found outside of the joint capsule and completely separate from the joint capsule ▪ i.e. Lateral collateral ligament of the knee 3. Intra-articular (aka Intracapsular): Found within (inside) the joint cavity, in the cavity itself ▪ i.e. Anterior cruciate ligament of the knee Page 7 of 8 Canadian College of Massage & Hydrotherapy GAP – Topic #9 Intro to Arthrology & Syndesmology VASCULATURE AND INNERVATION OF JOINTS ➢ Joints receive their blood supply from articular arteries, located in the joint capsule ➢ Joints also have a rich nerve supply, the nerve endings are found in the joint capsule ➢ Joints provide sensory information to the brain about proprioception via proprioceptive receptors (awareness of the position of the joint in space) ➢ Joints also have pain receptors, however not all structures within a joint will be pain sensitive Page 8 of 8