Orthopaedics basics (Bones and Joints Basics).pptx

Learn about the basics of bones and joints. Entire types and classifications of the same. Easy-to-understand language with relevant images.

1. ORTHOPAEDICS BASICS BONES AND JOINTS Dr. Saumya Kine MPT, COMT

2. SKELETAL SYSTEM Skeletal system forms the internal framework of the body.  Parts:  - Bones (Skeleton) - Joints - Cartilages - Ligaments

3. FUNCTIONS OF THE SKELETON (BONES) Provide shape and bony framework for support to the body Protection of vital organs Provide surface for muscles, tendon and ligament attachment thereby helping in producing movement Production of blood and blood cells Storage of calcium, minerals and fat

4. CLASSIFICATION OF BONES Based on shape Long Short Flat Irregular Sesamoid Pneumatic Developmental classification Membrane bones Cartilagenous bone Membrano-cartilagenous bones Regional classification Axial Appendicular

5. LONG BONES Each long bone has an elongated shaft (diaphysis) and two expanded ends (epiphyses) which are smooth and articular. Examples :  humerus, radius, ulna, femur, tibia and fibula

6. SHORT BONES Their shape is usually cuboid, cuneiform, trapezoid, or scaphoid. Examples: tarsal and carpal bones

7. FLAT BONES Flat bones resemble shallow plates and form boundaries of certain body cavities. Examples: bones in the vault of the skull, ribs, sternum and scapula

8. IRREGULAR BONES Bones that are irregular in shape and structure. Examples: vertebra, hip bone, and bones in the base of the skull 

9. PNEUMATIC BONES Certain irregular bones contain large air spaces lined by epithelium. T hey make the skull light in weight, help in resonance of voice, and act as air conditioning chambers for the inspired air. Examples: maxilla, sphenoid, ethmoid, etc. Commonly seen in birds

10. SESAMOID BONES These are bony nodules found embedded in the tendons or joint capsules. They have no periosteum and ossify after birth. They are related to an articular or nonarticular bony surface, and the surfaces of contact are covered with hyaline cartilage and lubricated by a bursa or synovial membrane.  Examples: patella, pisiform, fabella, etc. Functions of the sesamoid bones are: (a) to resist pressure; (b) to minimise friction; (c) to alter the direction of pull of the muscle; and (d) to maintain the local circulation.

11. STRUCTURE OF A LONG BONE A typical long bone has two ends or epiphyses (singular epiphysis), and an intermediate portion called the shaft or diaphysis. The part of the shaft which adjoins the epiphysis is called the metaphysis – one next to each epiphysis There is a thin plate of growth cartilage, one at each end, separating the epiphysis from the metaphysis. This is called the epiphyseal plate. At maturity, the epiphysis fuses with the metaphysis and the epiphyseal plate is replaced by bone. The articular ends of the epiphyses are covered with articular cartilage. The rest of the bone is covered with periosteum which provides attachment to tendons, muscles, ligaments, etc. 

12. BASED ON DEVELOPMENTAL ORIGIN Membrane (dermal) bones ossify in membrane (intramembranous or mesenchymal ossification), and are thus derived from mesenchymal condensations. Examples: bones of the vault of skull and facial bones. Cartilaginous bones ossify in cartilage ( intracartilaginous or endochondral ossification), and are thus derived from preformed cartilaginous models. Examples: bones of limbs, vertebral column and thoracic cage. Membrano -cartilaginous bones ossify partly in membrane and partly in cartilage.  Examples: clavicle, mandible, occipital, temporal, sphenoid. 

13. REGIONAL CLASSIFICATION AXIAL SKELETON skull, vertebral column, and thoracic cage APPENDICULAR SKELETON bones of the limbs, pelvic and pectoral girdle

14. STRUCTURE OF BONES 4 LAYERS Periosteum Compact bone Cancellous (spongy) bone Bone marrow

15. COMPACT BONE Compact bone is dense in texture like ivory, but is extremely porous. It is best developed in the cortex of the long bones. This is an adaptation to bending and twisting forces (a combination of compression, tension and shear) CANCELLOUS BONE Cancellous or spongy, or trabecular bone is open in texture, and is made up of a meshwork of trabeculae (rods and plates) between which are marrow containing spaces. The trabecular meshworks are of three primary types, namely: (a) meshwork of rods, (b) meshwork of rods and plates, and (c) meshwork of plates. Cancellous bone is an adaptation to compressive forces. 

16. BONE CELLS Osteoblasts: Concerned with ossification, these cells are rich in alkaline phosphatase, glycolytic enzymes and phosphorylases. ( Cells that form new bone) Osteocytes: These are mature bone cells which vary in activity, and may assume the form of an osteoclast or reticulocyte. These cells are rich in glycogen and PAS positive granules. ( cells inside the bone) Osteoclasts: These are multi-nucleate mesenchymal cells concerned with bone resorption. These have glycolytic acid hydrolases, collagenases and acid phosphatase enzymes. ( Large cells that dissolve the bone)

17. BLOOD SUPPLY OF THE BONES Nutrient artery: This vessel enters the bone around its middle and divides into two branches, one running towards either end of the bone. Each of these further divide into a leash of parallel vessels which run towards the respective metaphysis. Metaphyseal vessels: These are numerous small vessels derived from the anastomosis around the joint. They pierce the metaphysis along the line of attachment of the joint capsule. Epiphyseal vessels: These are vessels which enter directly into the epiphysis. Periosteal vessels: The periosteum has a rich blood supply, from which many little vessels enter the bone to supply roughly the outer-third of the cortex of the adult bone. Blood supply to the inner 2/3rds of the bone comes from the nutrient artery and the outer 1/3rd from the periosteal vessels.

18. JOINTS Joint is a junction between two or more bones Articular surfaces covered with hyaline (articular) cartilage. Between the articular surfaces there is a joint cavity filled with synovial fluid. Joint is surrounded by fibrous joint capsule lined by synovial membrane.

19. CLASSIFICATION STRUCTURAL CLASSIFICATION FUNCTIONAL CLASSIFICATION REGIONAL CLASSIFICATION ACC. TO NO. OF ARTICULATING BONES Fibrous Joints Cartilaginous joints Synovial Joints Synarthrosis Amphiarthrosis Diarthrosis 1) Skull type 2) Vertebral type 3) Limb type Simple joint Compound joint Complex joint

20. FIBROUS JOINTS (IMMOVABLE OR FIXED) CARTILAGINOUS JOINTS (SLIGHTLY MOVABLE) SYNOVIAL JOINTS (FREELY MOVABLE) Sutures Syndesmosis Gomphosis Primary or  Synchondrosis Secondary or Symphysis Ball-and-socket or spheroidal joints  Sellar or saddle joints  Condylar or bicondylar joints  Ellipsoid joints Hinge joints  Pivot or trochoid joints  Plane joints

21. FIBROUS JOINTS Bones are joint by fibrous tissue hence completely immovable or fixed. Sutures immovable, found in skull Syndesmosis bones connected by interosseus ligament. Eg inferior tibiofibular joints Gomphosis peg and socket like root of tooth in its bony socket.

22. CARTILAGINOUS JOINTS Bones joined by cartilage. Minimal movement permissible, eg : vertebral joints Primary (Synchondrosis): Bones united by a plate of hyaline cartilage.  These joints are temporary in nature because after a certain age the cartilaginous plate is replaced by bone. Eg : Joint b/w epiphysis and diaphysis of a growing long bone Secondary (Symphysis): Articular surfaces covered by thin layer of hyaline cartilage and united by a disc of fibrocartilage.  These joints are permanent and persist throughout life. Eg : pubic symphysis

23. BALL AND SOCKET JOINT One end of the bone is shaped like a ball, and it fits into a hollow socket at the end of another joint.  Allows for radial movement in almost any direction (flexion extension, abduction adduction, MR LR, circumduction). Eg : Hip and shoulder joints

24. ELLIPSOID JOINT Articular surfaces include an oval, convex male surface fitting into an elliptical, concave female surface. Aka condyloid or bicondylar joint. Movements permitted around both the axes, flexion-extension around transverse axis abduction-adduction around AP axis. Combination of movements leads to circumduction, but no rotation around vertical axis Eg : wrist, MCP, MTP,  interphallangeal joints

25. SADDLE JOINT Articular surfaces are reciprocally concave and convex Movements similar to ellipsoid with some additional degree of rotation Eg : 1st CMC of thumb, calcaneocuboid joint

26. HINGE JOINT Pulley shaped articular surfaces. Movements permitted in one plane around transverse axis (flexion, extension) Eg : elbow, ankle joint

27. PIVOT JOINT Articular surfaces consist of central boney pivot (peg) surrounded by an ossteoligamentous ring. Movements permistted in one plane around vertical axis (pronation, supination) i.e. only allow rotation Eg : superior and inferior radioulnar joints, atlanto -axial joint

28. PLANE JOINT Articular surfaces are almost flat / plane. Permit gliding movements (translations) in any direction Eg : intercarpal, intertarsal joints, AC joint

29. ACC. TO NO OF ARTICULATING BONES Simple joints: Only two bones take part in the formation of the joint. Eg : Interphallangeal joints Compound: More than two bones articulate within one capsule. Eg : wrist, elbow Complex: When joint cavity is divided into two by an intra-articular disc. Eg : TMJ,  sternoclavicular joint

30. TYPES OF MOVEMENT Flexion:  Bending or flexing a limb. (Closing a joint). Reducing the angle of the joint Extension:  straightening or extending a limb. (Opening a Joint)  Abduction:  Moving a limb away from midline of the body.  Adduction:  moving a limb towards or across the midline of the body Elevation: Upward movement Depression: Downward movement Protraction: Forward movement of the shoulder girdle Retraction: Backward movement of the shoulder girdle Pronation: Palm of hand facing downward Supination: Palm of hand facing upward Dorsiflexion: Toes pointing up Plantarflexion: Toes pointing down Inversion: Sole facing towards midline Eversion: Sole facing away from the midline