Chapter 39

Assessment

Health History The nursing assessment of the patient with musculoskeletal dysfunction includes a health history and physical examination that evaluate the effects of the musculoskeletal disorder on the patient. The nurse is concerned with assisting patients who have musculoskeletal problems to maintain their general health and functional status, accomplish their ADLs, and manage their treatment programs. The nurse must promote a healthy lifestyle by discussing the importance of nutrition and nutritional supplements, regular exercise, and maintaining an appropriate weight. The nurse should also address problems associated with immobility and advocate for evidence-based periodic musculoskeletal health screenings. Through an individualized plan of nursing care, the nurse helps the patient achieve optimal health. Common Symptoms During the interview and physical assessment, the patient with a musculoskeletal disorder may report pain, tenderness, and altered sensations (Weber & Kelley, 2014). The nurse is responsible to assess and document this information. Figure 39-3 • Body movements produced by muscle contraction. Pain Most patients with diseases and traumatic conditions or disorders of the muscles, bones, and joints experience pain. Bone pain is typically described as a dull, deep ache that is "boring" in nature. This pain is not typically related to movement and may interfere with sleep. Muscular pain is described as soreness or aching and is referred to as "muscle cramps." Fracture pain is sharp and piercing and is relieved by immobilization. Sharp pain may also result from bone infection with muscle spasm or pressure on a sensory nerve. Joint pain is felt around or in the joint and typically worsens with movement (Swartz, 2014). TABLE 39-1 Age-Related Changes of the Musculoskeletal System Musculoskeletal System Structural Changes Functional Changes History and Physical Findings Bones Gradual, progressive loss of bone mass after 30 years of age Vertebral collapse Bones fragile and prone to fracture—vertebrae, hip, wrist Loss of height Postural changes Kyphosis Loss of flexibility Flexion of hips and knees Back pain Osteoporosis Fracture Muscles Increase in collagen and resultant fibrosis Muscles diminish in size (atrophy); wasting Tendons less elastic Loss of strength and flexibility Weakness Fatigue Stumbling Falls Loss of strength Diminished agility Decreased endurance Prolonged response time (diminished reaction time) Diminished tone Broad base of support History of falls Joints Cartilage—progressive deterioration Thinning of intervertebral discs Stiffness, reduced flexibility, and pain interfere with activities of daily living Diminished range of motion Stiffness Loss of height Ligaments Lax ligaments (less-than-normal strength; weakness) Postural joint abnormality Weakness Joint pain on motion; resolves with rest Crepitus Joint swelling/enlargement Osteoarthritis (degenerative joint disease) Rest relieves most musculoskeletal pain. Pain that increases with activity may indicate joint sprain, muscle strain, or compartment syndrome, whereas steadily increasing pain points to the progression of an infectious process (osteomyelitis), a malignant tumor, or neurovascular complications. Radiating pain occurs in conditions in which pressure is exerted on a nerve root. The time of day that the pain occurs may be important to evaluate. Those experiencing pain with a rheumatic disorder experience pain that is worse in the morning, especially upon waking. Tendonitis worsens during the early morning and eases by midday, whereas osteoarthritis worsens as the day progresses (Swartz, 2014). Pain is variable, and its assessment and nursing management must be individualized. The nurse assesses the patient's pain as described in Chapter 12. Specific assessments that the nurse should make regarding the pain include the following: Is the body in proper alignment? Are the joints symmetrical or are bony deformities present? Is there any inflammation or arthritis, swelling, warmth, tenderness, or redness? Is there pressure from traction, bed linens, a cast, or other appliances? Is there tension on the skin at a pin site? The patient's pain and discomfort must be managed successfully. Not only is pain exhausting, but also, if prolonged, it can force the patient to become increasingly withdrawn and dependent on others as the musculoskeletal disorder continues. Altered Sensations Sensory disturbances are frequently associated with musculoskeletal problems. The patient may describe paresthesias, which are sensations of burning, tingling, or numbness. These sensations may be caused by pressure on nerves or by circulatory impairment. Soft tissue swelling or direct trauma to these structures can impair their function. The nurse assesses the neurovascular status of the involved musculoskeletal area. Questions that the nurse should ask regarding altered sensations include the following: Is the patient experiencing abnormal sensations, such as burning, tingling, or numbness? If the abnormal sensation involves an extremity, how does this feeling compare to sensation in the unaffected extremity? When did the condition begin? Is it getting worse? Does the patient also have pain? (If the patient has pain, then the questions and assessments for pain discussed previously should be followed.) Past Health, Social, and Family History When assessing the musculoskeletal system, the nurse should gather pertinent data to include in the patient's health history, such as occupation (e.g., does the patient's work require physical activity or heavy lifting?), exercise patterns, alcohol consumption, tobacco use, and dietary intake (e.g., calcium and vitamin D). Concurrent health conditions (e.g., diabetes, heart disease, chronic obstructive pulmonary disease, infection, and preexisting disability) and related problems (e.g., familial or genetic abnormalities [see Chart 39-1]) need to be considered when developing and implementing the plan of care. Any previous history of trauma or injury to the musculoskeletal system or a history of falls should be included as well (Weber & Kelley, 2014). p. 1121 p. 1122 Chart 39-1 GENETICS IN NURSING PRACTICE Musculoskeletal Disorders Genetic musculoskeletal disorders vary in presentation and can tend to present at different points in time across the life span. Consideration must be given to other genetic disorders that will impact the musculoskeletal system. Some examples of inherited genetic musculoskeletal disorders include: Autosomal Dominant: Achrondroplasia Nail-Patella syndrome Osteogenesisimperfecta Polydactyl Van der Woude syndrome Autosomal Recessive: Tay Sachs Forms of Muscular Dystrophy: Becker muscular dystrophy Congenital muscular dystrophy Distal muscular dystrophy Duchene muscular dystrophy (X-linked) Emery-Dreyfuss muscular dystrophy (X-linked) Facioscapulohumeral muscular dystrophy (autosomal dominant) Limb-girdle muscular dystrophy (autosomal dominant and autosomal recessive forms) Other genetic disorders that impact the musculoskeletal system: Amyotrophic lateral sclerosis (neurologic disorder) Ehlers-Danlos syndrome (connective tissue disorder) Marfan syndrome (connective tissue disorder) Spina bifida (neurologic disorder) Stickler syndrome (connective tissue disorder) Nursing Assessments Refer to Chart 5-2: Genetics in Nursing Practice: Genetic Aspects of Health Assessment, in Chapter 5 Family History Assessment Related to Genetic Musculoskeletal Disorders Assess for other similarly affected family members in the past three generations. Assess for the presence of other related genetic conditions (e.g., hematologic, cardiac, integumentary conditions). Determine the age at onset (e.g., fractures present at birth such as osteogenesis imperfecta, hip dislocation present at birth in DDH, or early-onset osteoporosis). Patient Assessment Specific to Genetic Musculoskeletal Disorders Assess stature for general screening purposes (unusually short stature may be related to achondroplasia; unusually tall stature may be related to Marfan syndrome). Assess for disease-specific skeletal findings (e.g., pectusexcavatum, scoliosis, long fingers [Marfan syndrome], osteoarthritis of the hip or waddling gait). Assessment findings that could indicate a genetic musculoskeletal disorder include: Bone pain Enlarged hands or feet Excessive height, short stature, or decrease in height Flat feet or highly arched feet Frequency of bone-related injuries or unexplained fractures Hypermobility of joints Large or small head circumference Protruding jaw or forehead Unexplained changes in muscle tone (hypotonia) Genetics Resources The National Osteoporosis Foundation, www.nof.org NIH Osteoporosis and Related Bone Diseases National Resource Center, www.niams.nih.gov/Health_Info/Bone See Chapter 8, Chart 8-7 for components of genetic counseling. DDH, developmental dysplasia of the hip(s) The Fracture Risk Assessment Tool (FRAX®) The Fracture Risk Assessment Tool (FRAX®) was developed in 2008 by a task force convened by the World Health Organization (WHO). It is a tool that predicts a patient's 10-year risk of fracturing a hip or other major bone, which includes the spine, forearm, or shoulder (NOF, 2016b). The tool may be accessed online, where it automatically calculates a patient's odds of fracture. Data entered are validated risks for fracture, and include: age (risk increases with increasing age) gender (risk is higher in females) body mass index (risk is higher with lower body mass indices) history of a previous fracture parental history of hip fracture current cigarette smoker current use of a corticosteroid (e.g., prednisone) history of rheumatoid arthritis alcohol intake of 3 or more drinks per day history of secondary causes/risks for osteoporosis, which include any of the following: type I diabetes osteogenesis imperfecta untreated long-standing hyperthyroidism hypogonadism or premature menopause chronic malnutrition or malabsorption syndromes chronic liver disease An additional validated risk factor that may be entered into the FRAX® is the patient's bone mineral density (BMD), based upon bone densitometry results, if those results are hip-based (see later discussion). However, while entering BMD results in the FRAX® provides a more accurate fracture risk calculation, it is not necessary (American College of Rheumatology, 2016). Thus, the FRAX® provides a good estimate of fracture risk in patients who may not have submitted to BMD testing. Patients who should be assessed for hip or major bone fracture risk include men and postmenopausal women over the age of 50, patients with known low BMD, and patients with known secondary causes/risks for osteoporosis See Chapter 41 for further discussion of osteoporosis. Assessing the Arms, Hands, and Fingers video Click to Show Assessing the Legs, Feet, and Toes video Click to Show Assessing the Musculoskeletal and Neurological Systems video Click to Show Physical Assessment An examination of the musculoskeletal system ranges from a basic assessment of functional capabilities to sophisticated physical examination maneuvers that facilitate diagnosis of specific bone, muscle, and joint disorders. The extent of assessment depends on the patient's physical complaints, health history, and physical clues that warrant further exploration. The nursing assessment is primarily a functional evaluation, focusing on the patient's ability to perform ADLs. Techniques of inspection and palpation are used to evaluate the patient's posture, gait, bone integrity, joint function, and muscle strength and size. In addition, assessing the skin and neurovascular status is an important part of a complete musculoskeletal assessment. The nurse should also understand and be able to perform correct assessment techniques on patients with musculoskeletal trauma. When specific symptoms or physical findings of musculoskeletal dysfunction are apparent, the nurse carefully documents the examination findings and shares the information with the primary provider, who may decide that a more extensive examination and a diagnostic evaluation are necessary. Posture The normal curvature of the spine is convex through the thoracic portion and concave through the cervical and lumbar portions. Common deformities of the spine include kyphosis, which is an increased forward curvature of the thoracic spine that causes a bowing or rounding of the back, leading to a hunchback or slouching posture. The second deformity of the spine is referred to as lordosis, or swayback, an exaggerated curvature of the lumbar spine. A third deformity is scoliosis, which is a lateral curving deviation of the spine (see Fig. 39-4). Kyphosis can occur at any age and may be caused by degenerative diseases of the spine (e.g., arthritis or disc degeneration), fractures related to osteoporosis, and injury or trauma (Swartz, 2014). It may also be seen in patients with other neuromuscular disease. Lordosis can affect persons of any age. Common causes of lordosis include tight low back muscles, excessive visceral fat, and pregnancy as the woman adjusts her posture in response to changes in her center of gravity. Scoliosis may be congenital, idiopathic (without an identifiable cause), or the result of damage to the paraspinal muscles (e.g., muscular dystrophy). During inspection of the spine, the entire back, buttocks, and legs are exposed. The examiner inspects the spinal curves and trunk symmetry from posterior and lateral views. Standing behind the patient, the examiner notes any differences in the height of the shoulders or iliac crests. Shoulder and hip symmetry, as well as the line of the vertebral column, is inspected with the patient erect and with the patient bending forward (flexion). Scoliosis is evidenced by an abnormal lateral curve in the spine; shoulders that are not level; an asymmetric waistline; and a prominent scapula, which is accentuated by bending forward. The examiner should then instruct the patient to bend backward (extension) with the examiner supporting the patient by placing hands on the posterior iliac spine (Swartz, 2014). Older adults experience a loss in height due to the loss of vertebral cartilage and osteoporosis-related vertebral compression fractures. Therefore, an adult's height should be measured during each health screening. Gait Gait is assessed by having the patient walk away from the examiner for a short distance. The examiner observes the patient's gait for smoothness and rhythm. Any unsteadiness or irregular movements (frequently noted in older adult patients) are considered abnormal. A limping motion is most frequently caused by painful weight bearing. In such instances, the patient can usually pinpoint the area of discomfort, thus guiding further examination. If one extremity is shorter than another, a limp may also be observed as the patient's pelvis drops downward on the affected side with each step. The knee should be flexed during normal gait; therefore, limited joint motion may interrupt the smooth pattern of gait. Evaluation of the knee involves the joints, bones, ligaments, tendons, and cartilage, and may include tests for the anterior and collateral ligaments, medial and lateral ligaments, and medial meniscus (Swartz, 2014). In addition, a variety of neurologic conditions are associated with abnormal gait, such as a spastic hemiparesis gait (stroke), steppage gait (lower motor neuron disease), and shuffling gait (Parkinson's disease). Figure 39-4 • A normal spine and three abnormalities. A. Kyphosis: an increased convexity or roundness of the spine's thoracic curve. B. Lordosis: swayback; exaggeration of the lumbar spine curve. C. Scoliosis: a lateral curvature of the spine. Bone Integrity The bony skeleton is assessed for deformities and alignment. Symmetric parts of the body, such as extremities, are compared. Abnormal bony growths due to bone tumors may be observed. Shortened extremities, amputations, and body parts that are not in anatomic alignment are noted. Fracture findings may include abnormal angulation of long bones, motion at points other than joints, and crepitus (a grating or crackling sound or sensation) at the point of abnormal motion. Movement of fracture fragments must be minimized to avoid additional injury. The nurse should include the following observations (Weber & Kelley, 2014): If the affected part is an extremity, how does its overall appearance compare to the unaffected extremity? Can the patient move the affected part? If an extremity is involved, does each toe or finger have normal sensation and motion (flexion and extension), and is the skin warm or cool? What is the color of the part distal to the affected area? Is it pale? Dusky? Mottled? Cyanotic? Does rapid capillary refill occur? (The nurse can gently squeeze a nail until it blanches, then release the pressure. The amount of time for the color under the nail to return to normal is noted. Color normally returns within 3 seconds. The return of color is evidence of capillary refill.) Is a pulse distal to the affected area palpable? If the affected area is an extremity, how does the pulse compare to the pulse of the unaffected extremity? Is edema present? Is any constrictive device or clothing causing nerve or vascular compression? Does elevating the affected part or modifying its position affect the symptoms? Joint Function The articular system is evaluated by noting range of motion, deformity, stability, tenderness, and nodular formation. Range of motion is evaluated both actively (the joint is moved by the muscles surrounding the joint) and passively (the joint is moved by the examiner). The examiner is familiar with the normal range of motion of major joints. Precise measurement of range of motion can be made by a goniometer (a protractor designed for evaluating joint motion). Limited range of motion may be the result of skeletal deformity, joint pathology, or contracture (shortening of surrounding joint structures) of the surrounding muscles, tendons, and joint capsule. In older adult patients, limitations of range of motion associated with osteoarthritis may reduce their ability to perform ADLs. If joint motion is compromised or the joint is painful, the joint is examined for effusion (excessive fluid within the capsule), swelling, and increased temperature that may reflect active inflammation. An effusion is suspected if the joint is swollen and the normal bony landmarks are obscured. The most common site for joint effusion is the knee. If large amounts of fluid are present in the joint spaces beneath the patella, it may be identified by assessing for the balloon sign and for ballottement of the knee (see Fig. 39-5). If inflammation or fluid is suspected in a joint, consultation with a specialist (e.g., orthopedic surgeon or rheumatologist) is indicated. Joint deformity may be caused by contracture, dislocation (complete separation of joint surfaces), subluxation (partial separation of articular surfaces), or disruption of structures surrounding the joint. Weakness or disruption of joint-supporting structures may result in a weak joint that requires an external supporting appliance (e.g., brace). Palpation of the joint while it is moved passively provides information about the integrity of the joint. Normally, the joint moves smoothly. A snap or crack may indicate that a ligament is slipping over a bony prominence. Slightly roughened surfaces, as in arthritic conditions, result in crepitus as the irregular joint surfaces move across one another. The tissues surrounding joints are examined for nodule formation. Rheumatoid arthritis, gout, and osteoarthritis may produce characteristic nodules. The subcutaneous nodules of rheumatoid arthritis are soft and occur within and along tendons that provide extensor function to the joints. The nodules of gout are hard and lie within and immediately adjacent to the joint capsule itself. They may rupture, exuding white uric acid crystals onto the skin surface. Osteoarthritic nodules are hard and painless and represent bony overgrowth that has resulted from the destruction of the cartilaginous surface of bone within the joint capsule. They are frequently seen in older adults (Swartz, 2014). Often, the size of the joint is exaggerated by atrophy of the muscles proximal and distal to that joint. This is seen in rheumatoid arthritis of the knees, in which the quadriceps muscle may atrophy dramatically. In rheumatoid arthritis, joint involvement assumes a symmetric pattern (see Fig. 39-6). See Chapter 38 for further information about rheumatoid arthritis. Muscle Strength and Size The muscular system is assessed by noting muscular strength and coordination, the size of individual muscles, and the patient's ability to change position. Weakness of a group of muscles may indicate a variety of conditions, such as polyneuropathy, electrolyte disturbances (particularly potassium and calcium), myasthenia gravis, poliomyelitis, and muscular dystrophy. By palpating the muscle while passively moving the relaxed extremity, the nurse can determine the muscle tone. The nurse assesses muscle strength by having the patient perform certain maneuvers with and without added resistance. For example, when the biceps are tested, the patient is asked to extend the arm fully and then to flex it against resistance applied by the nurse. A simple handshake may provide an indication of grasp strength. The nurse may elicit muscle clonus (rhythmic contractions of a muscle) in the ankle or wrist by sudden, forceful, sustained dorsiflexion of the foot or extension of the wrist. Fasciculation (involuntary twitching of muscle fiber groups) may be observed. Figure 39-5 • Tests for detecting fluid in the knee. A. Technique for balloon sign. The medial and lateral aspects of the extended knee are milked firmly in a downward motion, which displaces any fluid downward. The examiner feels for any fluid entering the space directly inferior to the patella. When larger amounts of fluid are present, the subpatellar region feels as if it is "ballooning," and the balloon sign test is positive. B. Technique for ballottement sign. The medial and lateral aspects of the extended knee are milked firmly in a downward motion. The examiner pushes the patella toward the femur and observes for fluid return to the region superior to the patella. When larger amounts of fluid are present, the patella elevates, there is visible return of fluid to the region directly superior to the patella, and the ballottement test is positive. Photograph used with permission from Bickley, L. S. (2017). Bates' guide to physical examination and history taking (12th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. Figure 39-6 • Rheumatoid arthritis joint deformity with ulnar deviation of fingers and "swan neck" deformity of fingers (i.e., hyperextension of proximal interphalangeal joints with flexion of distal interphalangeal joints). The nurse measures the girth of an extremity to monitor increased size due to exercise, edema, or bleeding into the muscle. Girth may decrease due to muscle atrophy. The unaffected extremity is measured and used as the reference standard for the affected extremity. Measurements are taken at the maximum circumference of the extremity. It is important that the measurements be taken at the same location on the extremity, and with the extremity in the same position, with the muscle at rest. Distance from a specific anatomic landmark (e.g., 10 cm below the medial aspect of the knee for measurement of the calf muscle) should be indicated in the patient's record so that subsequent measurements can be made at the same point. For ease of serial assessment, the nurse may indicate the point of measurement by marking the skin. Variations in size greater than 1 cm are considered significant. p. 1125 p. 1126 Chart 39-2 ASSESSMENT Assessing for Peripheral Nerve Function Assessment of peripheral nerve function has two key elements: evaluation of sensation and evaluation of motion. The nurse may perform one or all of the following during a musculoskeletal assessment. Nerve Test of Sensation Test of Movement Peroneal Prick the skin midway between the great and second toe. Ask the patient to dorsiflex the foot and extend the toes. Tibial Prick the medial and lateral surface of the sole. Ask the patient to plantar flex toes and foot. Radial Prick the skin midway between the thumb and second finger. Ask the patient to stretch out the thumb, then the wrist, and then the fingers at the metacarpal joints. Ulnar Prick the distal fat pad of the small finger. Ask the patient to abduct all fingers. Median Prick the top or distal surface of the index finger. Ask the patient to touch the thumb to the little finger. In addition, observe whether the patient can flex the wrist. Skin In addition to assessing the musculoskeletal system, the nurse inspects the skin for edema, temperature, and color. Palpation of the skin may reveal whether any areas are warmer, suggesting increased perfusion or inflammation, or cooler, suggesting decreased perfusion, and whether edema is present. Cuts, bruises, skin color, and evidence of decreased circulation or inflammation can influence nursing management of musculoskeletal conditions. Neurovascular Status The nurse must perform frequent neurovascular assessments of patients with musculoskeletal disorders (especially of those with fractures) because of the risk of tissue and nerve damage. Chart 39-2 describes methods the nurse may use to evaluate peripheral nerve function. The nurse needs to be particularly aware of signs and symptoms of compartment syndrome (which is described in detail later in this unit) when assessing the patient with a musculoskeletal injury. This neurovascular problem is caused by pressure within a muscle compartment that increases to such an extent that microcirculation diminishes, leading to nerve and muscle anoxia and necrosis. Function can be permanently lost if the anoxic situation continues for longer than 6 hours. Assessment of neurovascular status (see Chart 39-3) is frequently referred to as assessment of CMS (circulation, motion, and sensation). (Hinkle 1119-1126) Hinkle, Janice L., Kerry Cheever. Lippincott's CoursePoint for Hinkle & Cheever: Brunner & Suddarth's Textbook of Medical-Surgical Nursing, 14th Edition. CoursePoint, 10/2017. VitalBook file.

Structure and function of muscular system

Muscles are attached by tendons to bones, connective tissue, other muscles, soft tissue, or skin. The muscles of the body are composed of parallel groups of muscle cells (fasciculi) encased in fibrous tissue called fascia (epimysium). The more fasciculi contained in a muscle, the more precise the movements. Muscles vary in shape and size according to the activities for which they are responsible. Skeletal (striated) muscles are involved in body movement, posture, and heat-production functions. Muscles contract to bring the two points of attachment closer together, resulting in movement. Skeletal Muscle Contraction Muscle Contraction animation Click to Show Each muscle cell (also referred to as a muscle fiber) contains myofibrils, which in turn are composed of a series of sarcomeres—the actual contractile units of skeletal muscle. Sarcomeres contain thick myosin and thin actin filaments. Muscle cells contract in response to electrical stimulation delivered by an effector nerve cell at the motor end plate. When stimulated, the muscle cell depolarizes and generates an action potential in a manner similar to that described for nerve cells. These action potentials propagate along the muscle cell membrane and lead to the release of calcium ions that are stored in a specialized organelle called sarcoplasmic reticulum. When there is a local increase in calcium ion concentration, the myosin and actin filaments slide across one another. Shortly after the muscle cell membrane is depolarized, it recovers its resting membrane voltage. Calcium is rapidly removed from the sarcomeres by active reaccumulation in the sarcoplasmic reticulum. When the calcium concentration in the sarcomere decreases, the myosin and actin filaments cease to interact, and the sarcomere returns to its original resting length (relaxation). Actin and myosin do not interact in the absence of calcium (Grossman & Porth, 2014). The contraction of muscle fibers can result in either isotonic or isometric contraction of the muscle. In isometric contraction, the length of the muscles remains constant but the force generated by the muscles is increased; an example of this is pushing against an immovable wall. Isotonic contraction is characterized by the shortening of the muscle without an increase in tension within the muscle; an example of this is flexing the forearm. In normal activities, many muscle movements are a combination of isometric and isotonic contraction. For example, during walking, isotonic contraction results in shortening of the leg, and isometric contraction causes the stiff leg to push against the floor. Energy is consumed during muscle contraction and relaxation. The main source of energy for the muscle cells is adenosine triphosphate (ATP), which is generated through cellular oxidative metabolism. At low levels of activity (i.e., sedentary activity), the skeletal muscle synthesizes ATP from the oxidation of glucose to water and carbon dioxide. During periods of strenuous activity, when sufficient oxygen may not be available, glucose is metabolized primarily to lactic acid, an inefficient process compared with that of oxidative pathways. Stored muscle glycogen is used to supply glucose during periods of activity. Muscle fatigue is thought to be caused by depletion of glycogen and accumulation of lactic acid. As a result, the cycle of muscle contraction and relaxation cannot continue (Grossman & Porth, 2014). During muscle contraction, the energy released from ATP is not completely used. The excess energy is dissipated in the form of heat. During isometric contraction, almost all of the energy is released in the form of heat; during isotonic contraction, some of the energy is expended in mechanical work. In some situations (i.e., shivering), the need to generate heat is the main stimulus for muscle contraction. p. 1118 p. 1119 The speed of the muscle contraction is variable. Myoglobulin is a hemoglobin-like protein pigment present in striated muscle cells that transports oxygen. Muscles containing large quantities of myoglobulin (red muscles) have been observed to contract slowly and powerfully (e.g., respiratory and postural muscles). Muscles containing little myoglobulin (white muscles) contract quickly (e.g., extraocular eye muscles). Most muscles contain both red and white muscle fibers (Grossman & Porth, 2014). Muscle Tone Muscle tone (tonus) is produced by the maintenance of some of the muscle fibers in a contracted state. Muscle spindles, which are sense organs in the muscles, monitor muscle tone. Muscle tone is minimal during sleep and is increased when the person is anxious. A muscle that is limp and without tone is described as flaccid; a muscle with greater-than-normal tone is described as spastic. Typically, upper motor neuron lesions produce increased tone, whereas lower motor neuron lesions produce decreased tone. For example, in conditions characterized by upper motor neuron destruction (e.g., cerebral palsy), muscle becomes hypertonic and reflexes become hyperactive. In contrast, conditions characterized by lower motor neuron destruction (e.g., muscular dystrophy), denervated muscle becomes atonic (soft and flabby) and atrophies (Grossman & Porth, 2014). See Chapter 65 for assessment of upper and lower motor function. Muscle Actions Muscle contraction produces movement. The body is able to perform a wide variety of movements as a result of the coordination of muscle groups (see Fig. 39-3). The prime mover is the muscle that causes a particular motion. The muscles assisting the prime mover are known as synergists. The muscles causing movement opposite to that of the prime mover are known as antagonists. An antagonist must relax to allow the prime mover to contract, producing motion. For example, when contraction of the biceps causes flexion of the elbow joint, the biceps are the prime movers and the triceps are the antagonists. A person with muscle paralysis (a loss of movement, possibly from nerve damage) may be able to retrain functioning muscles within the synergistic group to produce the needed movement. Muscles of the synergistic group then become the prime movers. Exercise, Disuse, and Repair Muscles need exercise to maintain function and strength. When a muscle repeatedly develops maximum or close to maximum tension over a long time, as in regular exercise with weights, the cross-sectional area of the muscle increases. This enlargement, known as hypertrophy, results from an increase in the size of individual muscle fibers without an increase in their number. Hypertrophy persists only if the exercise is continued. The opposite phenomenon occurs with disuse of muscle over a long period of time. Age and disuse cause loss of muscular function as fibrotic tissue replaces the contractile muscle tissue. The decrease in the size of a muscle is called atrophy. Bed rest and immobility cause loss of muscle mass and strength. When immobility is the result of a treatment modality (e.g., casting, traction, or bed rest), the patient can decrease the effects of immobility by isometric exercise of the muscles of the immobilized part. Quadriceps contraction exercises (tightening the muscles of the thigh) and gluteal setting exercises (tightening of the muscles of the buttocks) help maintain the larger muscle groups that are important in ambulation. Active and weight-resistance exercises of uninjured parts of the body maintain muscle strength. When muscles are injured, they need rest and immobilization until tissue repair occurs. The healed muscle then needs progressive exercise to resume its preinjury strength and functional ability. Gerontologic Considerations Multiple changes in the musculoskeletal system occur with aging (see Table 39-1) and bring complaints of pain and joint limitations. There is a loss of height due to osteoporosis (abnormal excessive bone loss), kyphosis (forward curvature of the thoracic spine), thinned intervertebral discs, compressed vertebral bodies, and flexion of the knees and hips. Numerous metabolic changes, including menopausal withdrawal of estrogen and decreased activity, contribute to osteoporosis (NOF, 2016a). Women lose more bone mass than men. In addition, bones change in shape and have reduced strength. Fractures are common. Collagen structures are less able to absorb energy. Increased inactivity, diminished neuron stimulation, and nutritional deficiencies contribute to the loss of muscle strength. In addition, remote musculoskeletal problems for which the patient has compensated may become new problems with age-related changes. For example, people who have had polio and who have been able to function normally by using synergistic muscle groups may discover increasing incapacity because of a reduced compensatory ability. Older adults may suffer from chronic musculoskeletal disorders that limit mobility and interfere with their ability to perform self-care. This may lead individuals to depend on others for completion of their activities of daily living (ADLs); in turn, they may grieve over the loss of independence. Despite these changes, the many effects of aging can be slowed if the body is kept healthy and active through positive lifestyle behaviors (Swartz, 2014). (Hinkle 1118-1119) Hinkle, Janice L., Kerry Cheever. Lippincott's CoursePoint for Hinkle & Cheever: Brunner & Suddarth's Textbook of Medical-Surgical Nursing, 14th Edition. CoursePoint, 10/2017. VitalBook file.

Structure and function of the skeletal system

There are 206 bones in the human body, divided into four categories classified by their shape: long, short, flat, and irregular. The long bones are found in the upper and lower extremities (e.g., the femur). Long bones are shaped like rods or shafts with rounded ends (see Fig. 39-1). The shaft, known as the diaphysis, is primarily cortical bone (compact bone). The ends of the long bones, called epiphyses, are primarily cancellous bone (trabecular bone). During childhood and adolescence, there is a layer of cartilage known as the epiphyseal plate, or growth plate, that separates the epiphysis from the diaphysis. The epiphyseal plate nurtures and facilitates longitudinal growth. The epiphyseal plate is calcified in adults. The ends of long bones are covered at the joints by articular cartilage, which is tough, elastic, and avascular tissue (Grossman & Porth, 2014). The short bones are the irregularly shaped bones located in the ankle and hand (e.g., metacarpals). The flat bones are located where extensive protection of underlying structures is needed (e.g., the sternum or skull). Finally, because of their shape, the irregular bones cannot be categorized in any other group and include bones such as the vertebrae and bones of the jaw. The shape and construction of a specific bone are determined by its function and the forces exerted on it. Bones are constructed of cortical or cancellous bone tissue. Cortical bone exists in areas where support is needed, and cancellous bone is found where hematopoiesis and bone formation occur. For example, long bones are designed for weight bearing and movement and tend to be composed primarily of cortical bone, whereas flat bones, which are important sites of hematopoiesis and frequently protect vital organs, are made of cancellous bone layered between compact bone. Short bones consist of cancellous bone covered by a layer of cortical bone. Irregular bones have unique shapes related to their function. Generally, irregular bone structure is similar to that of flat bones (Grossman & Porth, 2014). Figure 39-1 • Structure of a long bone; composition of compact bone. Bone is composed of cells, protein matrix, and mineral deposits. The cells are of three basic types—osteoblasts, osteocytes, and osteoclasts. Osteoblasts function in bone formation by secreting bone matrix. The matrix consists of collagen and ground substances (glycoproteins and proteoglycans) that provide a framework in which inorganic mineral salts are deposited. These minerals are primarily composed of calcium and phosphorus. Osteocytes are mature bone cells involved in bone maintenance; they are located in lacunae (bone matrix units). Osteoclasts, located in shallow Howship's lacunae (small pits in bones), are multinuclear cells involved in dissolving and resorbing bone. The microscopic functioning unit of mature cortical bone is the osteon, or Haversian system. The center of the osteon—the Haversian canal—contains a capillary. Around the capillary are circles of mineralized bone matrix called lamellae. Within the lamellae are lacunae that contain osteocytes. These are nourished through tiny structures called canaliculi (canals), which communicate with adjacent blood vessels within the Haversian system. Lacunae in cancellous bone are layered in an irregular lattice network known as trabeculae. Red bone marrow fills the lattice network. Capillaries nourish the osteocytes located in the lacunae (Grossman & Porth, 2014). Covering the bone is a dense, fibrous membrane known as the periosteum. This membranous structure nourishes bone and facilitates its growth. The periosteum contains nerves, blood vessels, and lymphatics. It also provides for the attachment of tendons and ligaments (Grossman & Porth, 2014). The endosteum is a thin, vascular membrane that covers the marrow cavity of long bones and the spaces in cancellous bone. Osteoclasts, which dissolve bone matrix to maintain the marrow cavity, are located near the endosteum in Howship's lacunae (Grossman & Porth, 2014). Bone marrow is a vascular tissue located in the medullary cavity (shaft) of long bones and in flat bones. Red bone marrow, located mainly in the sternum, ilium, vertebrae, and ribs in adults, is responsible for producing red blood cells, white blood cells, and platelets through a process called hematopoiesis. In adults, the long bone is filled with fatty, yellow marrow (Grossman & Porth, 2014). Bone tissue is well vascularized. Cancellous bone receives a rich blood supply through metaphyseal and epiphyseal vessels. Periosteal vessels carry blood to compact bone through minute Volkmann canals. In addition, nutrient arteries penetrate the periosteum and enter the medullary cavity through foramina (small openings). Arteries supply blood to the marrow and bone. The venous system may accompany arteries or may exit independently (Grossman & Porth, 2014). Bone Formation Osteogenesis (bone formation) begins before birth. Ossification is the process by which the bone matrix is formed and hard mineral crystals composed of calcium and phosphorus (e.g., hydroxyapatite) are bound to the collagen fibers. These mineral components give bone its characteristic strength, whereas the proteinaceous collagen gives bone its resilience (Grossman & Porth, 2014). Bone Maintenance Bone is a dynamic tissue in a constant state of turnover. Throughout the lifespan, a process known as bone remodeling occurs, in which old bone is removed and new bone is added to the skeleton (formation). During childhood and the teenage years, new bone is added faster than old bone is removed; therefore, bones become larger, heavier, and denser. This continues until peak bone mass is reached, typically by age 20 years. Remodeling maintains bone structure and function through simultaneous resorption and osteogenesis, and as a result, complete skeletal turnover occurs every 10 years (Grossman & Porth, 2014). The balance between bone resorption (removal or destruction) and formation is influenced by the following factors: physical activity; dietary intake of certain nutrients, especially calcium; and several hormones, including calcitriol (i.e., activated vitamin D), parathyroid hormone (PTH), calcitonin, thyroid hormone, cortisol, growth hormone, and the sex hormones estrogen and testosterone (Florence, Allen, Benedict, et al., 2013). Physical activity, particularly weight-bearing activity, acts to stimulate bone formation and remodeling. Bones subjected to continued weight bearing tend to be thick and strong. Conversely, people who are unable to engage in regular weight-bearing activities, such as those on prolonged bed rest or those with some physical disabilities, have increased bone resorption from calcium loss, and their bones become osteopenic (reduced in terms of mass) and weak. These weakened bones may fracture easily. Concept Mastery Alert Weight-bearing activity or exercise should not be confused with weight-resistance exercise. Weight-bearing activity, which supports bone maintenance, is any activity done while a person is on their feet that works a person's bones and muscles against gravity (e.g., walking, tennis). Weight-resistance exercise, on the other hand, uses weights or resistance to strengthen muscles. Good dietary habits are integral to bone health. Daily intake of approximately 1000 to 1200 mg of calcium is essential to maintaining adult bone mass. Good sources of calcium include low-fat milk, yogurt, and cheese. Foods with added calcium such as orange juice, cereals, and bread are also beneficial (IOF, 2015). Vitamin D also plays a major role in calcium absorption and bone health. Young adults need a daily vitamin D intake of 600 IU, whereas adults 50 years and older require a daily intake of 800 to 1000 IU to ensure good bone health (Institute of Medicine [IOM], 2010). Dietary sources of vitamin D include vitamin D-fortified milk and cereals, egg yolks, saltwater fish, and liver. Several hormones are vital in ensuring that calcium is properly absorbed and available for bone mineralization and matrix formation. Calcitriol functions to increase the amount of calcium in the blood by promoting absorption of calcium from the gastrointestinal tract. It also facilitates mineralization of osteoid tissue. A deficiency of vitamin D results in bone mineralization deficit, deformity, and fracture (IOF, 2015). PTH and calcitonin are the major hormonal regulators of calcium homeostasis. PTH regulates the concentration of calcium in the blood, in part by promoting movement of calcium from the bone. In response to low calcium levels in the blood, increased levels of PTH prompt the mobilization of calcium, the demineralization of bone, and the formation of bone cysts. Calcitonin, secreted by the thyroid gland in response to elevated blood calcium levels, inhibits bone resorption and increases the deposit of calcium in bone (Grossman & Porth, 2014). Both thyroid hormone and cortisol have multiple systemic effects with specific effects on bones. Excessive thyroid hormone production in adults (e.g., Graves' disease) can result in increased bone resorption and decreased bone formation. Increased levels of cortisol have these same effects. Patients receiving long-term synthetic cortisol or corticosteroids (e.g., prednisone) are at increased risk for steroid-induced osteopenia and fractures. Growth hormone has direct and indirect effects on skeletal growth and remodeling. It stimulates the liver and, to a lesser degree, the bones to produce insulin-like growth factor 1 (IGF-I), which accelerates bone modeling in children and adolescents. Growth hormone also directly stimulates skeletal growth in children and adolescents. It is believed that the low levels of both growth hormone and IGF-I that occur with aging may be partly responsible for decreased bone formation and resultant osteopenia (Grossman & Porth, 2014). The sex hormones testosterone and estrogen have important effects on bone remodeling. Estrogen stimulates osteoblasts and inhibits osteoclasts; therefore, bone formation is enhanced and resorption is inhibited. Testosterone has both direct and indirect effects on bone growth and formation. It directly causes skeletal growth in adolescence and has continued effects on skeletal muscle growth throughout the lifespan. Increased muscle mass results in greater weight-bearing stress on bones, resulting in increased bone formation. In addition, testosterone converts to estrogen in adipose tissue, providing an additional source of bone-preserving estrogen for aging men (U.S. Department of Health and Human Services [HHS], 2012). During the process of bone remodeling, osteoblasts produce a receptor for activated nuclear factor-kappa B ligand (RANKL) that binds to the receptor for activated nuclear factor-kappa B (RANK) present on the cell membranes of osteoclast precursors, causing them to differentiate and mature into osteoclasts, which causes bone resorption. Conversely, osteoblasts may produce osteoprotegerin (OPG), which blocks the effects of RANKL, thereby turning off the process of bone resorption. T cells that may become activated as a result of the inflammatory process may also produce RANKL, overriding the effects of OPG and causing continued bone resorption during times of stress and injury, which can lead to loss of bone matrix and fractures (Khosla, 2013). Research focused on developing medications that block the effects of RANKL has resulted in U.S. Food and Drug Administration (FDA) approval of denosumab (Prolia) in treating postmenopausal women with osteoporosis (National Osteoporosis Foundation [NOF], 2014) (see Chapter 41). Blood supply to the bone also affects bone formation. With diminished blood supply or hyperemia (congestion), osteogenesis and bone density decrease. Bone necrosis occurs when the bone is deprived of blood (Grossman & Porth, 2014). Bone Healing Most fractures heal through a combination of intramembranous and endochondral ossification processes. When a bone is fractured, the bone begins a healing process to reestablish continuity and strength. The bone fragments are not patched together with scar tissue; instead, the bone regenerates itself. Fracture healing occurs in the bone marrow, where endothelial cells rapidly differentiate into osteoblasts; in the bone cortex, where new osteons are formed; in the periosteum, where a hard callus (fibrous tissue) is formed through intramembranous ossification peripheral to the fracture, and where cartilage is formed through endochondral ossification adjacent to the fracture site; and in adjacent soft tissue, where a bridging callus forms that provides stability to the fractured bones. When a fracture occurs, the body's response is similar to that after injury elsewhere in the body. The repair of a simple fracture occurs in essentially four stages. These include the following (Grossman & Porth, 2014): Stage I: Hematoma formation occurs during the first 1 to 2 days of the fracture. Bleeding into the injured tissue and local vasoconstriction occur, and a hematoma forms at the site of the fracture. Cytokines are released, initiating the fracture healing processes by causing replicating cells known as fibroblasts to proliferate, which in turn causes angiogenesis to occur (i.e., the growth of new blood vessels). Granulation tissue begins to form within the clot and becomes dense. At the same time, degranulated platelets and inflammatory cells release growth factor, which stimulates the generation of osteoclasts and osteoblasts. Stage II: Fibrocartilaginous callus formation occurs with the formation of granulation tissue. Fibroblasts and osteoblasts migrate into the fractured site and begin the reconstruction of bone. The fibroblasts produce a fibrocartilaginous soft callus bridge that connects the bone fragments. Although tissue repair may reach maximum girth by the end of the second or third week, it is still not strong enough for weight bearing. Stage III: Bony callus formation (ossification) usually begins during the third or fourth week of fracture healing and continues until a firm bony union is formed. During this stage, mature bone gradually replaces the fibrocartilaginous callus and the excess callus is gradually reabsorbed by the osteoclasts. During this stage, the fracture site feels immovable and appears aligned on x-ray. At this time, it is usually safe to remove a cast, if one is present. Stage IV: Remodeling occurs as necrotic bone is removed by the osteoclasts. Compact bone replaces spongy bone around the periphery of the fracture. Although the final structure of the remodeled bone resembles the original unbroken bone, a thickened area on the surface of the bone may remain after healing. Remodeling may take months to years, depending on the extent of bone modification needed, the function of the bone, and the functional stresses on the bone. Serial x-rays are used to monitor the progress of bone healing. The type of bone fractured, the adequacy of blood supply, the condition of the fracture fragments, the immobility of the fracture site, and the age and general health of the person influence the rate of fracture healing. Adequate immobilization is essential until there is x-ray evidence of bone formation with ossification. When fractures are treated with internal or external fixation techniques, the bony fragments can be placed in direct contact. Primary bone healing occurs through cortical bone (Haversian) remodeling. Little or no cartilaginous callus develops. Immature bone develops from the endosteum. There is an intensive regeneration of new osteons, which develop in the fracture line by a process similar to normal bone maintenance. Fracture strength is obtained when the new osteons have become established. (Hinkle 1115-1117) Hinkle, Janice L., Kerry Cheever. Lippincott's CoursePoint for Hinkle & Cheever: Brunner & Suddarth's Textbook of Medical-Surgical Nursing, 14th Edition. CoursePoint, 10/2017. VitalBook file.

Diagnostic evaluation

X-Ray Studies Bone x-rays determine bone density, texture, erosion, and changes in bone relationships. X-ray study of the cortex of the bone reveals any widening, narrowing, or signs of irregularity. Joint x-rays reveal fluid, irregularity, spur formation, narrowing, and changes in the joint structure. Multiple x-rays, with multiple views (e.g., anterior, posterior, lateral), are needed for full assessment of the structure being examined. Serial x-rays may be indicated to determine the status of the healing process. Chart 39-3 Indicators of Peripheral Neurovascular Dysfunction Circulation Color: Pale, cyanotic, or mottled Temperature: Cool Capillary refill: More than 3 seconds Motion Weakness Paralysis Sensation Paresthesia Unrelenting pain Pain on passive stretch Absence of feeling p. 1126 p. 1127 Computed Tomography A computed tomography (CT) scan, which may be performed with or without the use of oral or intravenous (IV) contrast agents, shows a more detailed cross-sectional image of the body. It may be used to visualize and assess tumors; injury to the soft tissue, ligaments, or tendons; and severe trauma to the chest, abdomen, pelvis, head, or spinal cord. It is also used to identify the location and extent of fractures in areas that are difficult to evaluate (e.g., acetabulum) and not visible on x-ray (Van Leeuwen & Bladh, 2016). Magnetic Resonance Imaging Magnetic resonance imaging (MRI) is a noninvasive imaging technique that uses magnetic fields and radio waves to create high-resolution pictures of bones and soft tissues. It can be used to visualize and assess torn muscles, ligaments, and cartilage; herniated discs; and a variety of hip or pelvic conditions. The patient does not experience any pain during the procedure. The MRI scanner is noisy, and it may take 30 to 90 minutes to complete the test. Because an electromagnet is used, patients with any metal implants (i.e., cochlear implants), clips, or pacemakers are not candidates for MRI (Van Leeuwen & Bladh, 2016). Quality and Safety Nursing Alert Jewelry, hair clips, hearing aids, credit cards with magnetic strips, and other metal-containing objects must be removed before the MRI is performed; otherwise, they can become dangerous projectile objects or cause burns. Credit cards with magnetic strips may be erased, and nonremovable cochlear devices can become inoperable; therefore, their presence is a contraindication for MRI. In addition, transdermal patches (e.g., nicotine patch [NicoDerm], nitroglycerin transdermal [Transderm-Nitro], scopolamine transdermal [TransdermScop], clonidine transdermal [Catapres-TTS]) that have a thin layer of aluminized backing must be removed before MRI because they can cause burns. The primary provider should be notified before the patches are removed. To enhance visualization of anatomic structures, an IV contrast agent may be used. Patients who experience claustrophobia may be unable to tolerate the confinement of closed MRI equipment without sedation. Open MRI systems are available, but they use lower-intensity magnetic fields, which produce lower-quality images. Advantages of open MRI include increased patient comfort, reduced problems with claustrophobic reactions, and reduced noise. Arthrography Arthrography is used to identify the cause of any unexplained joint pain and progression of joint disease. A radiopaque contrast agent or air is injected into the joint cavity to visualize the joint structures, such as the ligaments, cartilage, tendons, and joint capsule. The joint is put through its range of motion to distribute the contrast agent while a series of x-rays are obtained. If a tear is present, the contrast agent leaks out of the joint and is evident on the x-ray image (Van Leeuwen & Bladh, 2016). Bone Densitometry Bone densitometry is used to evaluate BMD. This can be performed through the use of x-rays or ultrasound. The most common modalities used include dual-energy x-ray absorptiometry (DXA or DEXA), quantitative computed tomography (QCT), and quantitative ultrasound (QUS). DXA measures BMD and predicts fracture risk through accurate monitoring of bone density changes in patients with osteoporosis who are undergoing treatment. The density of bones in the spine, hip, and wrist may be calculated, as well as the total body. Peripheral dual-energy x-ray absorptiometry (pDXA) may be an alternative test that measures BMD of the forearm, finger, or heel, although its ability to project hip or spine fracture risk is less accurate than DXA. Bone density may vary among different skeletal areas; therefore, BMD results may be normal at one site but low at another. Because these tests only measure density at specific sites, they may miss abnormal findings in other skeletal areas. Thus, although the BMD of the heel can be used to diagnose and monitor osteoporosis, predicting bone fracture risk related to osteoporosis is best achieved through DXA of the hip and spine. Hence, DXA is the most commonly prescribed diagnostic test for determining BMD (NOF, 2014; Van Leeuwen & Bladh, 2016). See Chapter 42 for a further discussion of osteoporosis risks. Nursing Interventions Before the patient undergoes any of the imaging studies described previously (i.e., x-rays, CT scans, MRIs, arthrography, bone densitometry), the nurse prepares the patient. For these studies, the patient must lie still. During an MRI study, the patient may hear a knocking sound. In addition, the nurse assesses for conditions that may require special consideration during the study or that may be contraindications to the study (e.g., pregnancy; claustrophobia; inability to tolerate required positioning due to age, debility, or disability; metal implants). If contrast agents will be used for the CT scan, MRI, or arthrography, the patient is assessed for possible allergies (Van Leeuwen & Bladh, 2016). The patient having an arthrogram may feel some discomfort or tingling during the procedure. After the arthrogram, a compression elastic bandage may be applied if prescribed, and the joint is usually rested for 12 hours. Strenuous activity should be avoided until approved by the primary provider. The nurse provides additional comfort measures (e.g., mild analgesia, ice) as appropriate and explains to the patient that it is normal to experience clicking or crackling in the joint for 24 to 48 hours after the procedure until the contrast agent or air is absorbed. Bone Scan A bone scan is performed to detect metastatic and primary bone tumors, osteomyelitis, some fractures, and aseptic necrosis, and to monitor the progression of degenerative bone diseases. A bone scan may accurately identify bone disease before it can be detected on x-ray; as such, it may diagnose a stress fracture in a patient who continues to experience pain after x-ray findings are negative (Van Leeuwen & Bladh, 2016). A bone scan requires the injection of a radioisotope through an IV line; the scan is performed 2 to 3 hours afterward. At this point, distribution and concentration of the isotope in the bone are measured. The degree of nuclide uptake is related to the metabolism of the bone; areas of abnormal bone formation will appear brighter. An increased uptake of the isotope is seen in primary skeletal disease (osteosarcoma), metastatic bone disease, inflammatory skeletal disease (osteomyelitis), and fractures that do not heal as expected. Nursing Interventions Prior to the bone scan, the nurse inquires about possible allergies to the radioisotope and assesses for any condition that would contraindicate performing the procedure (e.g., pregnancy, breast-feeding). The nurse should educate the patient about why the bone scan may be indicated and explain that it can assist in the identification of bone disease before it can be detected on an x-ray. The nurse should explain that the patient may experience moments of discomfort from the isotope (e.g., flushing, warmth) but provide reassurance that the radionuclide poses no radioactive hazard (Van Leeuwen & Bladh, 2016). In addition, the patient is encouraged to drink plenty of fluids to help distribute and eliminate the isotope. Before the scan, the nurse asks the patient to empty the bladder, because a full bladder interferes with accurate scanning of the pelvic bones. Arthroscopy Arthroscopy allows direct visualization of a joint through the use of a fiberoptic endoscope. Thus, it is a useful adjunct to diagnosing joint disorders. Biopsy and treatment of tears, defects, and disease processes may be performed through the arthroscope. The procedure takes place in the operating room under sterile conditions with either injection of a local anesthetic agent into the joint or general anesthesia. A large-bore needle is inserted, and the joint is distended with saline. The arthroscope is introduced, and joint structures, synovium, and articular surfaces are visualized. After the procedure, the puncture wound is closed with adhesive strips or sutures and covered with a sterile dressing. Complications are rare but may include infection, hemarthrosis, neurovascular compromise, thrombophlebitis, stiffness, effusion, adhesions, and delayed wound healing (Van Leeuwen & Bladh, 2016). Nursing Interventions After the arthroscopic procedure, the joint is wrapped with a compression dressing to control swelling. In addition, ice may be applied to control edema and enhance comfort. Frequently, the joint is kept extended and elevated to reduce swelling. The nurse monitors and documents the neurovascular status (see Chart 39-3). Analgesic agents are given as needed. The patient is instructed to avoid strenuous activity of the joint, and exercises must be approved by the primary provider. The patient and family are instructed to monitor for signs and symptoms of complications (e.g., fever, excessive bleeding, swelling, numbness, cool skin) and the importance of notifying the primary provider should any of these occur (Van Leeuwen & Bladh, 2016). Arthrocentesis Arthrocentesis (joint aspiration) is carried out to obtain synovial fluid for purposes of examination or to relieve pain due to effusion. Examination of synovial fluid is helpful in the diagnosis of septic arthritis and other inflammatory arthropathies and reveals the presence of hemarthrosis (bleeding into the joint cavity), which suggests trauma or a bleeding disorder. Normally, synovial fluid is clear, pale, straw colored, and scanty in volume. Using aseptic technique, the physician inserts a needle into the joint and aspirates fluid. Anti-inflammatory medications may be injected into the joint. A sterile dressing is applied after aspiration. There is a risk of infection after this procedure. Nursing Interventions The nurse should review the procedure with the patient and its indications. Hair may need to be removed from the site before the procedure. Pain may be a concern; telling the patient that analgesics may be given to alleviate discomfort during the procedure may help decrease anxiety. Ice may be prescribed for the first 24 to 48 hours postprocedure; the patient should be educated about why ice may be indicated (i.e., to diminish edema formation and pain). If antibiotics are prescribed postprocedure, the patient must be educated about their use and reminded to take medications as prescribed. The patient and family are educated about the possible signs and symptoms of complications, particularly infection and bleeding (e.g., fever, excessive bleeding, swelling, numbness, cool skin) and the importance of promptly notifying the health care provider if any of these occur (Van Leeuwen & Bladh, 2016). Electromyography Electromyography (EMG) provides information about the electrical potential of the muscles and the nerves leading to them. The test is performed to evaluate muscle weakness, pain, and disability. The purpose of the procedure is to determine any abnormality of function and to differentiate muscle and nerve problems. An EMG can be used to identify the extent of damage if nerve function does not return within 4 months of an injury. Needle electrodes are inserted into selected muscles, and responses to electrical stimuli are recorded on an oscilloscope. Warm compresses may relieve residual discomfort after the study. Nursing Interventions Before the patient undergoes an EMG, the nurse inquires if the patient is taking any anticoagulant medications and assesses for any active skin infection. An EMG is usually contraindicated in patients receiving anticoagulant therapy (e.g., warfarin) because the needle electrodes may cause bleeding within the muscle. EMG also may be contraindicated in patients with extensive skin infections due to the risk of spreading infection from the skin to the muscle. The nurse instructs the patient to avoid using any lotions or creams on the day of the test (Van Leeuwen & Bladh, 2016). If the nurse finds that the patient is taking an anticoagulant or has a skin infection, the primary provider is notified. Biopsy Biopsy may be performed to determine the structure and composition of bone marrow, bone, muscle, or synovium to help diagnose specific diseases. It involves excising a sample of tissue that can be analyzed microscopically to determine cell morphology and tissue abnormalities. Nursing Interventions The nurse educates the patient about the procedure and assures the patient that analgesic agents will be provided. The nurse monitors the biopsy site for edema, bleeding, pain, hematoma formation, and infection. Ice is applied as prescribed to control bleeding and edema. In addition, antibiotics and analgesic agents are given as prescribed. The patient is instructed to report signs of redness, bleeding, or pain at the biopsy site as well as fever or chills to the primary provider (Van Leeuwen & Bladh, 2016). Laboratory Studies Examination of the patient's blood and urine is used to identify the presence and amount of chemicals and other substances. The results may indicate a primary musculoskeletal problem (e.g., Paget's disease of the bone), a developing complication (e.g., infection), the baseline for instituting therapy (e.g., anticoagulant therapy), or the response to therapy, as well as possible causes of bone loss. Before surgery, coagulation studies are performed to detect bleeding tendencies (because bone is vascular tissue). Serum calcium levels are altered in patients with osteomalacia, parathyroid dysfunction, Paget's disease, metastatic bone tumors, or prolonged immobilization. Serum phosphorus levels are inversely related to calcium levels and are diminished in osteomalacia associated with malabsorption syndrome. Acid phosphatase is elevated in Paget's disease and metastatic cancer. Alkaline phosphatase is elevated during early fracture healing and in diseases with increased osteoblastic activity (e.g., metastatic bone tumors). Bone metabolism may be evaluated through thyroid studies and determination of calcitonin, PTH, and vitamin D levels. Serum enzyme levels of creatine kinase and aspartate aminotransferase become elevated with muscle damage. Serum osteocalcin indicates the rate of bone turnover. Urine calcium levels increase with bone destruction (e.g., parathyroid dysfunction, metastatic bone tumors, multiple myeloma) (Florence et al., 2013). Specific urine and serum biochemical markers can be used to provide information about the speed of bone resorption or bone formation, as well as to document the effects of therapeutic interventions prescribed for patients diagnosed with musculoskeletal disorders. These include urinary N-telopeptide of type 1 collagen (N-Tx) and deoxypyridinoline (Dpd), both of which reflect increased osteoclast activity and increased bone resorption. Conversely, elevated serum levels of bone-specific alkaline phosphatase (ALP), osteocalcin, and intact N-terminal propeptide of type 1 collagen (P1NP) reflect increased activity of osteoblasts and enhanced bone remodeling activity (NOF, 2016a). (Hinkle 1126-1129) Hinkle, Janice L., Kerry Cheever. Lippincott's CoursePoint for Hinkle & Cheever: Brunner & Suddarth's Textbook of Medical-Surgical Nursing, 14th Edition. CoursePoint, 10/2017. VitalBook file.

Structure and function of the articulate system

The junction of two or more bones is called a joint, or articulation. There are three basic kinds of joints: synarthrosis, amphiarthrosis, and diarthrosis joints. Synarthrosis joints, also referred to as fibrous joints, are immovable because of fibrous tissue banding (e.g., the skull sutures). Amphiarthrosis joints, also referred to as cartilaginous joints, allow limited motion (e.g., the vertebral joints and the symphysis pubis). Diarthrosis joints, also referred to as synovial joints, are freely movable joints (see Fig. 39-2). There are several types of diarthrosis joints: Ball-and-socket joints (e.g., the hip and the shoulder) permit full freedom of movement. Hinge joints permit bending in only one direction, either flexion or extension (e.g., the elbow and the knee). Saddle joints allow movement in two planes at right angles to each other. The joint at the base of the thumb is a saddle, biaxial joint. Pivot joints allow one bone to move around a central axis without displacement. An example of a pivot joint is the articulation between the radius and the ulna. They permit rotation for such activities as turning a doorknob. Gliding joints allow for limited movement in all directions and are represented by the joints of the carpal bones in the wrist. Figure 39-2 • Hinge joint of the knee. The ends of the articulating bones of a typical movable joint are covered with smooth hyaline cartilage. A tough, fibrous sheath called the joint capsule surrounds the articulating bones. The capsule is lined with a membrane, the synovium, which secretes the lubricating and shock-absorbing synovial fluid into the joint capsule. Therefore, the bone surfaces are not in direct contact. In some synovial joints (e.g., the knee), fibrocartilage discs (e.g., medial meniscus) are located between the articular cartilage surfaces. These discs provide shock absorption (Grossman & Porth, 2014). Ligaments (ropelike bundles of collagen fibrils) bind the articulating bones together. Tendons are cords of fibrous tissue that connect muscle to bone. Ligaments and tendons, which pass over the joint, provide joint stability. In some joints, interosseous ligaments (e.g., the cruciate ligaments of the knee) are found within the capsule and add anterior and posterior stability to the joint. Ligaments are pliable enough to allow movement of the joints; however, they can tear rather than stretch if they are subjected to excess stress. A bursa is a sac filled with synovial fluid that cushions the movement of tendons, ligaments, and bones over bones or other joint structures. Bursae can be found in the joints of the elbow, shoulder, hip, and knee. They may become inflamed, causing discomfort, swelling, and limited movement in that area. (Hinkle 1117-1118) Hinkle, Janice L., Kerry Cheever. Lippincott's CoursePoint for Hinkle & Cheever: Brunner & Suddarth's Textbook of Medical-Surgical Nursing, 14th Edition. CoursePoint, 10/2017. VitalBook file.