MED TERM Chapter 8 - Lecture notes orthopedics PDF

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full lecture notes on orthopedics (chapter 8)...

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MEDICAL TERMINOLOGY: Chapter 8 Orthopedics

Objectives of Chapter 8: 1. Identify structures of the skeletal system. 2. Describe the process of growth. 3. Describe common skeletal diseases, laboratory and diagnostic procedures, medical and surgical procedures, and drugs. 4. Form the plural and adjective forms of nouns related to orthopedics (skeletal). 5. Give the meanings of word parts and abbreviations related to orthopedics (skeletal). 6. Divide orthopedic (skeletal) words and build orthopedic (skeletal) words. 7. Spell and pronounce orthopedic (skeletal) words. 8. Research sound-alike and other orthopedic (skeletal) words. 9. Analyze the medical content and meaning of an orthopedic (skeletal) report

Anatomy and Physiology The skeletal system is the bony framework on which the body is built. The -skeleton is composed of 206 bones as well as cartilage and ligaments. The purpose of the skeletal system is to provide structural support for the body, work with the muscles to maintain body posture and produce movement and protect the body’s internal organs. The skeletal system is also known as the -skeletomuscular system or musculoskeletal system because of the close working -relationship between the bones and muscles

Anatomy of the Skeletal System Axial and Appendicular Skeleton The skeleton can be divided into two areas: the axial skeleton and the appendicular skeleton. The axial skeleton forms the central bony structure of the body around which other parts move. It consists of the bones of the head, chest, and back. The -appendicular skeleton consists of the bones of the shoulders, upper extremities, hips, and lower extremities

Bones of the Head The skull is the bony structure of the head. It includes both the cranium and facial bones. The cranium is the domelike bone at the top of the head. Within the -cranium is the cranial cavity, which contains the brain and other structures. There are eight bones in the cranium. A suture is the joint where two cranial bones meet. The frontal bone forms the forehead and top of the cranium and ends at the coronal suture. The two parietal bones form the upper sides and posterior parts of the cranium.

Between these bones is the sagittal suture, which runs from front to back. The occipital bone forms the posterior base of the cranium. It contains the foramen magnum, a large, round opening through which the spinal cord passes to join the brain. The two temporal bones form the lower sides of the cranium. Each temporal bone contains an opening for the external ear canal. The mastoid process is a projection from the temporal bone just behind the ear. The inferior temporal bone ends in the sharp styloid process, a point of attachment for ligaments to the hyoid bone in the anterior neck. The sphenoid bone, a large, irregularly shaped bone, forms part of the central base and sides of the cranium and the posterior walls of the eye sockets. A bony cup in the sphenoid bone holds the pituitary gland. The ethmoid bone forms the posterior nasal septum that divides the nasal cavity into right and left sides and forms the medial walls of the eye sockets. The frontal bone, sphenoid bones, and ethmoid bones all contain hollow sinuses. The facial bones support the nose, cheeks, and lips and protect the eyes and internal structures of the nose, mouth, and upper throat. There are 12 bones in the face. The two nasal bones form the bridge of the nose and the roof of the nasal cavity. The vomer is a narrow wall of bone that forms the inferior part of the nasal septum and continues posteriorly to join the sphenoid bone. The two lacrimal bones are small, flat bones within the eye sockets, near the lacrimal (tear) glands. Each zygoma or zygomatic bone is a cheek bone that goes to the edge of the eye socket. The maxilla is the upper jawbone. It contains the roots of the upper teeth and two hollow maxillary sinuses. The maxilla consists of two maxillary bones fused at the midline. The two palatine bones are small, flat bones that form the posterior hard palate. The mandible is the lower jawbone. It is the only movable bone in the skull. The roots of the lower teeth are in the mandible. Each side of the mandible ends in two bony tips; one tip is under the zygoma, while the other tip forms a movable joint (the temporomandibular joint) with the temporal bone just in front of the ear. There are also three tiny bones in each middle ear: the malleus, incus, and stapes. Collectively, these are known as the ossicles or the ossicular chain because they are arranged in a row. They are active in the process of hearing. The hyoid bone is a flat, U–shaped bone in the anterior neck. It does not connect directly to any other bones. It is attached by ligaments to the styloid process of each temporal bone.

Bones of the Chest The chest contains the thorax or rib cage. Within the thorax is the thoracic cavity, which contains the heart, lungs, and other structures. The sternum or breastbone is in the center of the anterior thorax. It consists of the triangular-shaped manubrium, the body of the sternum, and the inferior tip or xiphoid process . There are 12 pairs of ribs. Rib pairs 1–7 (true ribs) are attached to the vertebrae posteriorly and to the sternum anteriorly by costal cartilage. Cartilage is a smooth, firm, but flexible connective tissue. The costochondral joint is where the cartilage meets the rib. Rib pairs 8–10 (false ribs) are attached to the vertebrae posteriorly but are only indirectly attached to the sternum by long lengths of costal cartilage. Rib pairs 11 and 12 (floating ribs) are attached to the vertebrae posteriorly but are not attached to the sternum.

Bones of the Back The spine or backbone is a vertical column of bones. It is also known as the vertebral column or spinal column. The vertebral column supports the weight of the head, neck, and trunk of the body and protects the spinal cord. The vertebral column contains 24 individual vertebrae, plus the sacrum and coccyx. It is divided into five regions: the cervical vertebrae, the thoracic vertebrae, the lumbar vertebrae, the sacrum, and the coccyx. The cervical vertebrae (C1–C7) are in the neck. The first cervical vertebra (C1, the atlas) is directly below the occipital bone of the cranium. Its appearance is different from the other cervical vertebrae because it must form a joint that allows the head to move up and down. The second cervical vertebra (C2, the axis) fits into the atlas to form a joint that allows the head to move from side to side. The thoracic vertebrae (T1–T12) are in the chest. Each thoracic vertebra joins with one pair of 12 pairs of ribs. The lumbar vertebrae (L1–L5) are in the lower back. The lumbar vertebrae are larger than the cervical or thoracic vertebrae because they bear the weight of the head, neck, and trunk of the body. The sacrum is a group of five fused vertebrae that are not individually numbered, except for the first sacral vertebra (S1). The sacrum joins with the hip bones in the posterior pelvis. The coccyx or tail bone is a group of several small, fused vertebrae that are not individually numbered. Many of the vertebrae share common features: a vertebral body (circular, flat area), a spinous process (a long, bony projection that juts out in the midline along a person’s back), two transverse processes (bony projections to each side), and a vertebral foramen (The hole through which the spinal cord passes). Between most vertebrae are intervertebral disks. The outer wall of each disk is fibrocartilage, and the inside is filled with nucleus pulposus, a gelatinous substance. The disks act as cushions to absorb the impact during body movements. Bones of the Shoulders The shoulder bones include a clavicle and a scapula on the right and left sides. The clavicle or collar bone is a thin, rod-like bone on each side of the anterior neck. It connects to the manubrium of the sternum and laterally to the scapula. The scapula or shoulder blade is a triangular-shaped bone on either side of the vertebral column in the upper back. It has a long, bony blade across its upper half that ends in a flat projection (the acromion ) that connects to the clavicle. The glenoid fossa, a shallow depression, is where the head of the humerus (upper arm bone) joins the scapula to make the shoulder joint.

Bones of the Upper Extremities The upper extremity contains the upper arm and lower arm (forearm). The humerus is the long bone in the upper arm. The head of the humerus fits into the glenoid fossa of the scapula to form the shoulder joint. At its distal end, the humerus joins with both the radius and the ulna to form the elbow joint. The radius is one of the two bones in the forearm. It lies on the thumb side of the forearm. At its distal end, it connects to the bones of the wrist. The ulna lies on the little finger side of the forearm. At its

proximal end is the olecranon, a large, square projection that forms the point of the elbow. At its distal end, the ulna also connects to the bones of the wrist.

Wrist, Hand, and Fingers The wrist contains eight small carpal bones arranged in two rows. One row connects to the radius and ulna. The other row connects to the bones of the hand. Each hand contains five metacarpal bones , one for each finger. Each finger contains three phalangeal bones or phalanges (except the thumb, which contains two), arranged end to end. The distal phalanx is the final bone at the very tip of each finger. The fingers are also known as digits or rays . The metacarpophalangeal (MCP) joint is between a metacarpal bone of the hand and a phalanx. The distal interphalangeal (DIP) joint is between the last two phalanges.

Bones of the Hips The pelvis includes the hip bones as well as the sacrum and coccyx of the vertebral column. The hip bones include an ilium, ischium, and pubis on each side of the vertebral column. The ilium, the most superior of the hip bones, has a broad, flaring rim known as the iliac crest. Posteriorly, each ilium joins to the sacrum. The ilium contains the acetabulum (the cup-shaped, deep socket of the hip joint). The ischium is the most inferior of the hip bones. Each ischium is one of the “seat bones” that you sit on. The pubis or pubic bone, a small bridge like bone, is the most anterior of the hip bones. Its two halves meet in the midline, where they form the pubic symphysis, a nearly immobile joint that has a cartilage pad between the bone ends. The pubis also forms the inferior part of the acetabulum.

Bones of the Lower Extremities The lower extremity contains the upper leg (thigh) and the lower leg. The femur or thigh bone is the long, weight-bearing bone in the upper leg. The head of the femur fits into the acetabulum to form the hip joint. The tibia or shin bone is the large bone on the medial (great toe) side of the lower leg. At its distal end, it has a bony prominence known as the medial malleolus. The fibula is the very thin bone on the lateral (little toe) side of the lower leg. Its proximal end connects to the tibia, not to the femur, and it is not a weight-bearing bone in the leg. Its distal end has a bony prominence known as the lateral malleolus. The malleoli are often mistakenly called the ankle bones. The patella or kneecap is a thick, round bone anterior to the knee joint. It is most prominent in thin people and when the knee is partially bent.

Ankle, Foot, and Toes Each ankle contains seven tarsal bones. The talus is the first tarsal bone, and the calcaneus or heel bone is the largest tarsal bone. The midfoot contains five metatarsal bones, one for each toe. The instep or arch of the foot contains both tarsal bones and metatarsal bones. Each toe or digit contains three

phalangeal bones or phalanges (except the great toe, which contains two). The distal phalanx is at the very tip of the toe. The toes are also known as digits or rays. The great toe is known as the hallux.

Joints, Cartilage, and Ligaments A joint or articulation is where two bones come together. There are three types of joints: suture, symphysis, and synovial. 1. A suture joint between two cranial bones is immovable and contains no cartilage. 2. A symphysis joint, such as the pubic symphysis or the joints between the -vertebrae, is a slightly movable joint with a cartilage pad or disk between the bones. 3. A synovial joint is a fully movable joint. There are two kinds of synovial joints: hinge joints (elbow and knee) that allow motion in two directions and ball-and-socket joints (shoulder and hip) that allow motion in many directions. A synovial joint joins two bones whose ends are covered with articular cartilage. Ligaments are strong fibrous bands of connective tissue that hold the two bones together in a synovial joint. The entire joint is encased in a joint capsule that has a fibrous outer layer and an inner membrane. This inner synovial membrane produces synovial fluid, a clear, thick fluid that lubricates the joint. A meniscus is a crescent-shaped cartilage pad found in some synovial joints, such as the knee.

The Structure of Bone Bone or osseous tissue is a type of connective tissue. The surface of a bone is covered with periosteum , a thick, fibrous membrane. A long bone such as the humerus or femur has a straight shaft or diaphysis and two widened ends—the proximal epiphysis and the distal epiphysis. It is at the epiphyseal plates that bone growth takes place. Along the diaphysis is a layer of dense compact cortical bone for weight bearing. Inside this is the medullary cavity, which is filled with yellow bone marrow that contains fatty tissue. In each epiphysis is cancellous bone or spongy bone. It is less dense than compact bone, and the spaces in it are filled with red bone marrow. There are small foramina (openings) in the bones where the blood vessels go through to the bone marrow.

Types of Bone Fractures Fracture Name Closed Fracture Open Fracture Nondisplaced Fracture Displaced Fracture

Description Broken bone does not break through the overlying skin Broken bone breaks through the overlying skin. It is also known as a compound fracture. Broken bone remains in its normal anatomical alignment Broken bone is pulled out of its normal anatomical alignment

Colles’ Fracture Comminuted Fracture Compression Fracture

Depressed Fracture Greenstick Fracture

Hairline Fracture

Oblique Fracture Spiral Fracture Transverse Fracture

Distal radius is broken by -falling onto an outstretched hand Bone is crushed into several small pieces Vertebrae are compressed together when a person falls onto the buttocks or when a vertebra collapses in on itself because of disease Cranium is fractured inward toward the brain Bone is broken on only one side. This occurs in children because part of the bone is still flexible cartilage. Very thin fracture line with the bone pieces still together. It is difficult to detect except on an xray Bone is broken on an oblique angle Bone is broken in a spiral because of a twisting force Bone is broken in a transverse plane perpendicular to its long axis

Physiology of Bone Growth Ossification is the gradual replacing of cartilage with bone that takes place during childhood and adolescence. In addition, new bone is formed along the epiphyseal growth plates at the ends of long bones as the body grows taller. Although mature bone is a hard substance, it is also a living tissue that undergoes change. About 10% of the entire skeleton is broken down and rebuilt each year. This process occurs in areas that are damaged or subjected to mechanical stress. Osteoclasts break down areas of old or damaged bone. Osteoblasts deposit new bone tissue in those areas. Osteocytes maintain and monitor the mineral content (calcium, phosphorus) of the bone. Almost all of the body’s calcium is stored in the bones, but calcium is also needed to help the heart and skeletal muscles contract. Calcium comes from foods but is also released into the blood as osteoclasts break down old or damaged bone.

Diseases Diseases of Bone and Cartilage Word or Phrase Avascular Necrosis

Bone Tumor

Description Death of cells in the epiphysis of a long bone, often the femur. This is caused by an injury, fracture, or dislocation that damages nearby blood vessels or by a blood clot that interrupts the blood supply to the bone. Treatment: Surgery to remove the dead bone, then a bone graft. For large areas of avascular necrosis, joint replacement surgery is done. Osteoma is a benign tumor of the bone. Osteosarcoma is a cancerous bone tumor in

Chondroma Chondromalacia Patellae

Fracture

Osteomalacia

Osteomyelitis

Osteoporosis

which osteoblasts, the cells that form new bone, multiply uncontrollably. It is also known as osteogenic sarcoma. Ewing’s sarcoma is a cancerous bone tumor that occurs mainly in young men. Treatment: Surgical removal of a benign tumor. Amputation of the limb followed by radiation therapy or chemotherapy drugs for a cancerous tumor Benign tumor of the cartilage. Treatment: Surgical removal, if large Abnormal softening of the patella because of thinning and uneven wear. The thigh muscle pulls the patella in a crooked path that wears away the underside of the bone. Treatment: Strengthening of the thigh muscle to correct the direction of its contraction Broken bone due to an accident, injury, or disease process. Fractures are categorized according to how the bone breaks (see Figure 818 and Table 8-1). A fracture caused by force or torsion during an accident or sports activity is a stress fracture. A fracture caused by a disease process such as osteoporosis, bone cancer, or metastases to the bone is a pathologic fracture. Fractures that are allowed to heal without treatment often show malunion or malalignment of the fracture fragments. Treatment: Closed reduction and manipulation to align the fracture pieces, application of a cast. Surgery: Open reduction and internal fixation using wires, pins, screws, or plates. Abnormal softening of the bones due to a deficiency of vitamin D in the diet or inadequate exposure to the sun whose rays make vitamin D in the skin. In children, this causes rickets with bone pain and fractures. Treatment: Vitamin D supplement, sun exposure. Infection in the bone and the bone marrow. Bacteria enter the bone following an open fracture, crush injury, or surgical procedure. Treatment: Antibiotic drug. Abnormal thinning of the bone structure. When bone breakdown exceeds new bone formation, calcium and phosphorus are lost, and the bone becomes osteoporotic (porous) with many small areas of demineralization (see Figure 8-19). This

can cause a compression fracture as a vertebra collapses in on itself. The vertebral column decreases in height, the patient becomes shorter, and there is an abnormal curvature of the upper back and shoulders (dowager’s hump). Osteoporosis can also cause a spontaneous fracture (pathologic fracture) of the hip or femur. Sometimes it is unclear whether an older patient fell and fractured the bone or whether the osteoporotic bone itself spontaneously fractured and caused the patient to fall. Osteoporosis occurs in postmenopausal women and older men. Estradiol in women stimulates bone formation, and loss of estradiol at menopause leads to osteoporosis. A lack of dietary calcium and a lack of exercise contribute to the process. Treatment: Bone density test for diagnosis; drug to decrease the rate of bone resorption or drug to activate estradiol receptors, and calcium supplement.

Diseases of the Vertebrae Word or Phrase Ankylosing Spondylitis

Kyphosis

Lordosis

Scoliosis

Description Chronic inflammation of the vertebrae that leads to fibrosis, fusion, and restriction of movement of the spine. Treatment: Nonsteroidal anti-inflammatory drug. Abnormal, excessive, posterior curvature of the thoracic spine. It is also known as humpback or hunchback. The back is said to have a kyphotic curvature. Kyphoscoliosis is a complex curvature with components of both kyphosis and scoliosis...