Skeletal System

Question of the Day How long does the inflammatory phase of healing last and what are the six steps? Duration is 3-5 days directly following injury; 6 steps: vasoconstriction, release of chemical mediators, vasodilation, margination, phagocytosis, and clotting

Two Parts Axial Skeleton (80 total bones) Skull, sternum, ribs, vertebrae Appendicular skeleton (126 total bones) Upper extremities (shoulder girdles=64), lower extremities (pelvic girdles=62) How many bones total? How many in an infant?

Function Foundation/Framework Protection of vital organs Movement (can’t do without muscles) Blood cell production Avg of 2.6 million erythrocytes (RBCs) produced each second by marrow Storage of minerals

Types of Bones Long Short Flat Irregular Sesamoid http://www.human-anatomy.net/images/anatomy_for_exercise/Classification_of_bones.jpg

Long Bone Epiphysis Metaphysis Diaphysis Epiphyseal Plate (Physis) End of bone Metaphysis Trans from epiphys plate to diaphysis Diaphysis Shaft of bone (growing part) Epiphyseal Plate (Physis) Growth plate Starts as cartilage and is replaced by bone http://www.web-books.com/eLibrary/Medicine/Physiology/Skeletal/long_bone.jpg

Bone Image Diaphysis (shaft) Metaphysis (transition) Epiphyseal Plate (growth plate) Epiphysis (end of bone)

Bone and Articular Cartilage Articular=places where bones meet (articulate) Smooth surface at end of bones to help with gliding during mvmnt Deterioration can occur Arthritis Chondral defects http://www.eorthopod.com/sites/default/files/images/knee_cart_surg_intro01.jpg

Bony Injuries Contusions Infections (osteomyelitis) Apophysitis http://www.boostphysio.com/blog/wp-content/uploads/2010/06/osgood-schlatter.gif Bony Injuries Contusions Infections (osteomyelitis) Apophysitis Growth plates http://www.cjthakkar.com/old/photo/osgood.jpg

Bony Injuries Fractures Multiple Types Simple/Closed Compound/Open Displaced Non-Displaced Complete Incomplete Compound/Open Multiple Types http://www.waybuilder.net/sweethaven/MedTech/Surgery02/927fig0502.jpg

Fracture Video http://www.youtube.com/watch?v=03aWABddimA&feature=related (joe theisman)

Questions of the day What are the 5 types of bone (list an example of each)? What are the four parts of a long bone? Answer: Long (femur), Short (carpals or tarsals), Flat (bones of skull; ribs), Irregular (vertebrae, pelvic), sesamoid (patella); Epiphysis (end), physis (growth plate), metaphysis (transition), diaphysis (shaft)

Specific Fracture (Fx) Types Linear Along length MOI: landing from high jump (force through long axis) Comminuted More than 2 pieces MOI: hard blow, awkward fall Difficult to manage http://www.chezlark.com/pictures/Fracture.jpg

Specific Fx Types Transverse Directly across bone MOI: direct blow Oblique Angled across bone MOI: twisting/torsion Spiral S-shaped (usually oblique in nature) MOI: twisting with other end fixed http://ajs.sagepub.com/content/30/6/900/F3.large.jpg

Specific Fx Types Depression Abnormal concavity to bone MOI: direct blow Impacted One end wedged into other MOI: significant load Stress Very small, incomplete fractures (don’t usually show on x-ray) MOI: chronic stress on bone http://www.imagingpathways.health.wa.gov.au/includes/images/osteo/radial%20fracture.jpg

Specific Fx Types Greenstick Incomplete fx Adolescents Apophyseal Portion of bone starts to pull away MOI: strong msl contraction at growth plate http://www.mayoclinic.com/images/image_popup/ww5rl55.jpg

Specific Fx Types Avulsion Physeal (SALTER-HARRIS) http://www.consultantlive.com/image/image_gallery?img_id=1419701&t=1244224256843 Specific Fx Types Avulsion Portion of bone is actually pulled off MOI: progression of apophyseal fx; ligamentous stretch (ligament stronger than bone) Physeal (SALTER-HARRIS) Fx through growth plate MOI: any of aforementioned http://www.davidlnelson.md/images/Salter-Harris.jpg

Fracture Healing Types of bone cells Osteocytes= bone cells Osteoblasts= bone-forming cells Osteoclasts= cells that absorb and remove bone

Fracture Healing Video http://www.youtube.com/watch?v=qVougiCEgH8 (1:13)

Fx Healing cont. Fracture occurs Bony tissue is immobilized Disrupts periosteum and capillaries Bony tissue is immobilized May require realignment Osteoblasts form callus Bridge between fx areas Osteoclasts reshape bone Wolff’s law: bone adapts to the stresses that are placed upon it http://upload.wikimedia.org/wikipedia/commons/f/f5/ Communitive_midshaft_humeral_fracture_callus.jpg

Fx Healing (http://www. scribd DAY 1: Hematoma (collection of blood forms as capillaries are torn) DAY 1-5: Inflammatory Phase (WBC invade, clotting, healing starts) Day 7: Soft Callus forms (bony scar tissue forms matrix) Day 21-42: Hard Callus (soft callus replaced with stronger bony tissue) Day 42+: Remodels callus and continues to strengthen

Fx Healing cont. Cast usually removed at 4 weeks Start to stress bone at approx 4-6 weeks to help with remodeling Weight bearing bones, site of fracture, and bones that have more difficulty healing take longer

Surgical Fracture Videos http://www.youtube.com/watch?v=qKeJd0j2J4E&feature (Plated fibula) [2:27] http://img.medscape.com/pi/emed/ckb/orthopedic_surgery/1230552-1239870-1173.jpg

Surgical Fracture Videos http://www.youtube.com/watch?v=OuPecrbui3M&feature (IM rod of femur) [2:23] http://0.tqn.com/d/orthopedics/1/G/p/1/tibialrodap.jpg

Factors that Affect Bone/Healing Osteopenia; Osteoporosis Reduced bone mass without fx; end stage/progression with presence of deformity (pores in bone) Menstrual Irregularities Change in hormone production decreases bone strength Activity Level Wolff’s law

Factors that Affect Bone/Healing Smoking Nicotine cause vasoconstriction decreased blood flow to areas of bone that are growing/healing Age Older age slower healing time Kids tend to heal/remodel much better than adults

Bone Markings Processes of the bone are divided into two types. Those that form joints Those that connective tissue attach to (i.e. tendons, ligaments, etc.)

Processes to which connective tissue attach Tubercle – a small rounded process Tuberosity or styloid – a large rounded usually roughened process Trochanter – a large blunt projection

Processes to which connective tissue attach Crest – a prominent border or ridge on a bone Line – a ridge less prominent than a crest Spinous process – a sharp slender process Epicondyle – a prominence above a condyle

Processes that form joints Condyle – a large rounded articular prominence Head – a rounded articular projection Facet – a smooth flat surface