Special Populations










CHAPTER 30


Special Populations


OVERVIEW


There are a number of population subtypes that require special consideration in terms of the orthopaedic examination and intervention. These include pediatrics and geriatrics, and the whole spectrum of women’s health, in addition to the problems associated with a number of sports.


The Pediatric Athlete



The term pediatric refers to the 0- to 21-year age range, during which an individual undergoes many changes while aging, evolving, and maturing. During the preschool years, physical growth, neurologic growth, and maturation are quite rapid and apparent, with new skills being acquired at a quick pace.1 This process continues throughout the middle years (ages 6–11) at a somewhat slower pace. As a child enters puberty, the rapid development of physical and sexual characteristics become more apparent and is accompanied by important psychosocial development. It is important to remember that chronologic age does not necessarily correlate well with many physiologic and somatic changes.






The major characteristics of somatic and skeletal growth and maturation during adolescence are outlined in Table 30-1. In addition, the following differences exist between the adult and the pediatric patient2:










TABLE 30-1


Somatic and Skeletal Growth and Maturation During Adolescence































Characteristic


Description


Weight


In males, the average weight gain during its peak is approximately 9 kg per year with a range of 6–12.5 kg per year. The peaks of growth spurts in height, weight, and muscle occur at the same time


In females the average weight gain during its peak is approximately 8 kg per year with a range of 5.5–10.5 kg per year. The peaks of growth spurts in height, weight, and muscle occur in sequence in that order


Height


In general, linear growth first occurs in the lower extremities, followed by the torso and then the upper extremities


Males typically reach their peak height velocity (PHV) by 14 years. The growth of the shoulders in males is the most noticeable change


Females typically reach their PHV by 12 years. The growth of the hip and pelvis in females are the most notable changes


Body composition


In general, both males and females tend to increase both fat mass as well as fat-free mass from the early to middle adolescent years. However, while males may show a transient decrease in fat accumulation in the extremities during PHV, females continue to gain fat through late adolescence. The pattern of growth of fat-free mass is similar to that noted for growth in height and weight


Flexibility


As skeletal growth precedes that of musculotendinous growth during the early to middle adolescence, there is a relative decrease in musculotendinous flexibility in some adolescents, especially males. Decreased flexibility is particularly noticeable in the hamstrings and ankle dorsiflexors


Muscle growth and strength


Although muscle growth and strength is seen in both males and females, it is relatively more pronounced in males compared with females due to androgens


Bone mass


The female skeleton generally grows and fully matures (i.e., growth plate fusion) before the male skeleton. The largest percentage of lifetime acquisition of bone mineral density occurs during the second decade of life. Peak bone mass during adolescence is determined by genetic influences, exercise, calcium intake, and hormonal status


Data from Greydanus DE, Pratt HD. Adolescent growth and development, and sport participation. In: Patel DR, Greydanus DE, Baker RJ, eds. Pediatric Practice: Sports Medicine. New York, NY: McGraw-Hill; 2009:15–25.



img Cardiovascular system. The pediatric heart is smaller than that of the mature adult, resulting in a smaller capacity as a reservoir for blood, and thus a lower stroke volume at all levels of exercise, which is compensated for by an increased heart rate. As with the adult patient, systolic blood pressure (BP) rises during exercise in the pediatric patient, but the elevation is less. Finally, the thoracic cavity is obviously smaller in the younger child than that of the mature adult, resulting in the pediatric patient demonstrating a smaller vital capacity than the adult and an elevated resting respiration rate.3 The red blood cell count for young boys and girls are similar in comparable abilities to carry oxygen to exercising organs. After menarche, however, females demonstrate lower blood volume and fewer red blood cells with a resultant decreased oxygen carrying capacity and a lower mean BP.4 These differences result in the following responses to exercise in the pediatric patient:


img Until 12 years, absolute maximal oxygen uptake (VO2max) values increase at the same rate in both genders, although boys have higher values as early as 5 years. VO2max increases concomitantly with growth until 18 years in boys and 14 years in girls.


img The pattern of relative magnitudes of cardiovascular and ventilatory responses to progressive and sustained dynamic exercise appears to be qualitatively similar between adults and children.


img Children rely more on oxidative rather than anaerobic metabolism compared to adults.


img Children demonstrate greater energy expenditure during weight-bearing activities such as running and walking compared to adults.



img Musculoskeletal system. During infancy, early childhood, and preadolescents, muscle accounts for about 25% of body weight with the total number of muscle fibers established prior to birth or early in infancy. Postnatal changes in the distribution of type I and type II muscle fibers (see Chapter 1) are relatively complete by the end of the first year of life, with the muscle fiber size and mass increasing linearly from infancy to puberty. Throughout childhood until puberty, muscle strength and muscle endurance increase linearly with chronological age in boys and girls with muscle mass (absolute and relative) approximately 10% greater in boys than girls. Of interest is that training induced strength gains occur equally in both sexes during childhood without evidence of muscle hypertrophy until puberty. During this time, children possess muscle fiber numbers, types, and distribution similar to that of adults. During puberty, there is a rapid acceleration in muscle fiber size and muscle mass, especially in boys, with muscle mass increasing more than 30% per year. As would be expected, this increase in muscle mass results in a rapid increase in muscle strength in both sexes but there is a marked difference in strength levels between boys and girls. In boys, muscle mass and body weight and weight peak before muscle strength, whereas in girls, strength peaks before body weight. The increase in muscle hypertrophy is a result of increased androgens. In addition, agility, motor coordination, power, and speed also show improvement during puberty.


In addition, growth cartilage is present at the epiphyseal plate during puberty, the joint surface (articular cartilage), and the apophysis. The epiphyseal plate or growth plate is divided into zones differentiated from one another via structure and function (see Chapter 1). Growing bone is the weak musculoskeletal link in the young athlete. Similar physical demands that can result in muscle strain or ligament sprain in the skeletally mature patient may result in an epiphyseal plate injury in a young patient. Two factors that impact epiphyseal plate injury are (1) the ability of the growth plate to resist failure and (2) the forces applied to the bone or the stresses induced in the growth plate. The majority of epiphyseal fractures are due to high-velocity injuries.


A certain amount of load is necessary for normal bone growth and remodeling. In most long bones, epiphysis is at least partially ossified at an early age. However, in certain areas of the body (e.g., ischial tuberosity, iliac crest, the base of the fifth metatarsal), the epiphysis may not become ossified until the near end of the final growth spurt. Most of the bone mineral density (BMD) is acquired during the adolescent years, and bone mass may fail to accrue optimally because of dieting and weight loss. Because the strength development of bones lags behind that of ligaments and tendons, there is an increased risk of tendon or bone avulsion at the apophyseal insertion compared to a ligament injury.








Examination of the Pediatric Patient



In addition to the areas typically covered in the orthopaedic examination outlined in Chapter 4, a number of additional factors must be considered in the pediatric population. For example, when taking the history of a pediatric patient, the clinician should pay particular attention to the following2:



img Current life circumstances. The pediatric patient’s current health, attitudes and values of the child’s immediate family, and acculturation of the patient.


img Gender. Females and males develop differently, particularly during adolescence (Table 30-2).










TABLE 30-2


Differences in Adolescent Females Compared to Males
































Anatomic


Physiologic


Reduced muscle fiber size


Increased percentage of body fat (10–15 lb more)


Wide hips with narrower shoulders


Women have 40–45 less pounds of fat-free weight (bone, muscle, organs)


Shorter height (3–4 in on average)


Basal metabolic rate is relatively lower


Relatively smaller total articular surface area


Reduced testosterone levels


Relatively more fat around the thighs and hips


Skeletal maturation occurs earlier


Heart size and volume are smaller


Aerobic capacity is lower


Lung volume is smaller


Vital capacity is less


img Health history. Health and nutrition history, repeated hospitalizations, and so on.


img Developmental history. The pediatric patient’s past rate of achievement of developmental milestones, events that might have had profound effects on the patient either physically or psychologically.


img Extrapersonal interactions. The reaction of the pediatric patient to the treating clinician and the conditions under which the pediatric patient is observed.


img Age-related changes in muscle and muscle performance.


img The developing skeletal system. Examination of the pediatric patient requires an understanding of, and an awareness of, the timing of growth center appearance and epiphyseal closure. For example, the sequence and average timing of growth center appearance at the elbow are as follows5:


img Capitellum. Female, 4 months; male, 5 months.


img Medial epicondyle. Female, 5 years; male, 7 years.


img Trochlea. Female, 8 years; male, 9 years.


img Lateral epicondyle. Female, 11 years; male, 12 years.


Epiphyseal closure at the elbow occurs sequentially, first in the distal humerus, with the capitellum, lateral epicondyle, and trochlea fusing together at puberty (female, 14 years and male, 17 years), then fusing with the shaft.5 The medial epicondyle fuses later (female, 15 years and male, 18 years). The radial head and olecranon close at 14 years in females and 15 years in males.5


Growing musculoskeletal tissue is innately predisposed to specific injuries that vary greatly from injuries sustained by their skeletally mature counterparts. Most of this growth occurs in two phases from birth to adulthood. There is a rapid gain in growth in infancy and early childhood that slows down during middle childhood. The second rapid increase in growth occurs during adolescence. An injury that occurs during one of these phases, which is significant enough to interrupt the growth process, can present serious challenges.








ACQUIRED ORTHOPAEDIC CONDITIONS


Musculoskeletal injuries in individuals with an immature musculoskeletal system require a different set of considerations than injuries in adult individuals—children are not small adults.8 There is currently a concern that the increase in sports participation exposes children to a higher risk of musculoskeletal injuries that may negatively influence long-term health.8,9 In the developing skeleton, the epiphyseal growth plates are especially vulnerable, and injuries to these may result in significant limb-length discrepancies and angular deformities.8,10


Skeletal Fracture



The mechanical properties and healing qualities of skeletal bone are described in Chapters 1 and 2, respectively. In the pediatric population, the metaphysic–physis junction is an anatomic point of weakness. Fractures of bone in pediatric patients may be due to direct trauma, such as a blow, or indirect trauma, such as a fall on the outstretched hand (FOOSH injury), or a twisting injury. Three types of fractures occur more commonly in the pediatric population:



img Greenstick. A type of simple fracture in which only one side of the bone is fractured while the opposite side is bent. Because the bones in a pediatric patient have not fully developed, they are less rigid and brittle. This type of fracture tends to heal faster than other types.


img Avulsion. Avulsion occurs when a piece of bone attached to a tendon or ligament is torn away. In the younger population, ligaments and tendons are stronger than bone. When changes in muscle length do not match the changes in long-bone growth, tensile loads placed within the muscle predispose the pediatric patient to injury. Lower extremity avulsion fractures outnumber avulsion fractures of the upper extremity (UE). Common sites of avulsion fracture in the lower extremity include the anterior superior iliac spine (ASIS), anterior inferior iliac spine (AIIS), ischial tuberosity, and the base of the fifth metatarsal. Common sites of avulsion fracture in the UE include the medial humeral epicondyle and the proximal humerus. If a medial epicondyle avulsion fracture is suspected, it is important to assess the ulnar nerve, and for the presence of point tenderness over the medial epicondyle, swelling, ecchymosis, and valgus instability.


img Growth plate (physeal). This type of fracture involves an interference in the cartilaginous physis of long bones that may well or may not involve the metaphyseal or epiphyseal bone. The physis is the weakest link in the immature skeleton, and the open growth plates in long bones and at the apophysis make physeal injuries more likely to occur in the pediatric population, also in part due to the greater structural strength and integrity of the ligaments and joint capsules than of the growth plates and the fact that the physes of an adult have ossified. The morbidity and sequelae of a missed physeal injury are not easily remedied. Growth plate fractures can have severe consequences because of the potential for growth plate closure, which inhibits future longitudinal or angular growth resulting in limb-length discrepancies. Conversely, an injury near, but not at, the physis can stimulate increased bone growth.


With the increasing involvement of youth in organized sports, overuse injuries are becoming a frequent reality among children. The peak incidence of traumatic physeal injury is 11–12 years in girls, and 13–14 years in boys.11


The Salter and Harris classification is the preferred and accepted standard in North America for classifying physeal fracture patterns3:



img Type I. This type, which involves only the physis, occurs due to shearing forces in which there is complete separation of the epiphysis without fracture of the bone. These fractures are most commonly seen in the very young patient when the epiphyseal plate is relatively thick.


img Type II. This is the most common type of growth plate fracture resulting from shearing and bending forces. The line of separation traverses a variable distance along the epiphyseal plate and then makes its way through a segment of the bony metaphysis that results in a triangular-shaped metaphyseal fragment (also known as a Thurston Holland fragment).


img Type III. This typically results from shearing forces and results in intraarticular fractures from the joint surface to the deep zone of the growth plate and then along the growth plate to its periphery. These fractures are typically limited to the proximal tibial/distal femoral epiphysis and can result from valgus loading of the knee, which is frequently encountered in contact and collision sports.


img Type IV. These are intraarticular fractures that result from shearing forces. These fractures extend from the joint surface to the epiphysis across the entire thickness of the growth plate and then through a segment of the bony metaphysis. Management of these fractures is complex.


img Type V. These types of fractures, which are due to a crushing mechanism, are relatively uncommon.


The risk of growth disturbance is highest with types III, IV, and V fractures.







Clinical Findings

The most common clinical presentation with a pediatric fracture is pain, weakness, and functional loss of the involved area. The most common areas for epiphyseal fracture include the distal radius and the medial epicondyle, the proximal humerus, and the proximal tibia/distal femoral.


Intervention

In most cases, the medical management of a fracture involves immobilization through casting, splints, or surgical fixation to allow full healing to occur. Pediatric fractures tend to heal faster than an equivalent one in an adult. This can be advantageous: Children typically require shorter immobilization times. A disadvantage, however, is that any malpositioned fragments become immovable or fixed much earlier than in adults (3–5 days in a young child, 5–7 days in an older child, as opposed to 8–10 days in an adult). However, the normal process of bone remodeling in a child may correct malalignment, making near-anatomic reductions less important in children than in adults. Remodeling can be expected if the patient has two or more years of bone growth remaining. Rotational deformity remodels poorly, if at all, and is therefore corrected by surgical reduction. A further complication is that pediatric fractures may stimulate a longitudinal growth of the bone, making the bone longer than it would have been had it not been injured. This is particularly true for fractures of the femoral or tibial shaft.


Children tolerate prolonged immobilization much better than adults and disabling stiffness or loss of range of motion (ROM) is distinctly unusual after pediatric fractures. Physical therapy, if needed, typically begins after the immobilization period, and depending on the type and location of the fracture, it can involve any or all of the following:



img Pain management techniques including the use of noncontraindicated electrotherapeutic modalities (see Chapter 8) and manual techniques, including joint mobilizations.


img ROM exercises, following the hierarchy of progression outlined in Chapter 13.


img Strengthening exercises, beginning with isometrics and progressing using the hierarchy of progression outlined in Chapter 12.


img Gait and/or crutch training with an appropriate assistive device and following the prescribed prescription for weight bearing (see Chapter 6).


img Proprioception exercises for balance and coordination (see Chapter 14).


img Functional training including adaptive, supportive, or protective devices and activities of daily living (ADLs) and self-care.


img Patient and family education to decrease the risk of re-injury and to promote healing.


ACL Injury



ACL injuries are among the most severe and most frequent activity-related injuries sustained by active children.12 Lifelong knee function and quality of life (QoL) may also be affected due to a probable increase in the risk of developing early knee OA.8,13,14 There are two major challenges in the management of ACL injuries in the skeletally immature population8,15:



img to safely implement treatment interventions that provide the best possible long-term functional outcomes and,


img to reduce the risk of secondary meniscus injury or harm to the epiphyseal growth plates.






The distal femoral physis is the most active growth plate in the human body, contributed approximately 1 cm of growth per year, which in turn is responsible for 70% of the longitudinal growth of the femur and 37% of the growth of the lower limb.16 The proximal tibial physis contributes approximately 0.7 cm of growth per year, which equals 55% of tibial growth and 25% of lower limb growth.16


The mechanism of ACL injury is similar to that as in adults (see Chapter 20), with the most common being Alpine skiing and playing soccer. However, unlike with adults, the diagnostic accuracy of acute knee injuries in children is less certain, which may be explained by the fact that the knees of children have greater ligamentous laxity than those of adults.17,18 Thus, the combination of injury history, clinical examination (including the Lachman test and pivot shift test—see Chapter 20), and MRI is recommended to optimize the diagnostic accuracy of ACL injuries in the skeletally immature.8,19


The traditional approach to ACL injuries in the skeletally immature consisted of nonoperative management of active rehabilitation, activity limitations, and bracing until the child’s skeleton had neared the end of its growth.20,21 However, newer surgical techniques have allowed for early ACL reconstruction. The two most common surgical approaches for this population include8



img transphyseal ACL (adult) reconstruction, which requires the surgeon to drill a hole through both the proximal tibial physis and distal femoral physis to enable an anatomical reconstruction of the native ACL.


img physeal sparing ACL reconstruction, which occurs when the surgical procedure does not involve drilling graft holes through the epiphyseal growth plates.8


The postsurgical management program consists of exercises targeted toward regaining ROM, neuromuscular control, and muscle strength.


Juvenile Rheumatoid Arthritis



Juvenile rheumatoid arthritis (JRA) is a group of diseases that are manifested by chronic joint inflammation22,23 JRA is defined as persistent arthritis, lasting at least 6 weeks, in one or more joints in a child younger than 16 years of age, when all other causes of arthritis have been excluded.


The descriptive term juvenile idiopathic arthritis was adopted as an umbrella term to indicate a disease of childhood onset, characterized primarily by arthritis of no known etiology persisting for at least 6 weeks. JRA is the most prevalent pediatric rheumatic diagnosis among children in the United States. The exact etiology of JRA remains unclear, but the prevailing theory is that it is an inflammatory autoimmune disorder, activated by an external trigger, in a genetically predisposed host. JRA is classified as a systemic, pauciarticular, or polyarticular disease, according to onset within the first 6 months. The general history of JRA includes the following:



img Disease onset is either insidious or abrupt, with morning stiffness and arthralgia during the day.


img Individuals with JRA may have a school history of absences, and their abilities to participate in physical education classes may reflect the severity of the disease. Typically, patients with JRA and their parents and/or caregivers are concerned about missing school; in contrast, when psychogenic factors predominate (e.g., pain syndromes), patients and their parents and/or caregivers are more worried about returning to school than about missing school.


img Limping may be observed in individuals with more severe JRA; however, the presence of limping also raises the possibility of trauma or another orthopaedic problem.


img Injury suggests the possibility of trauma to a joint (e.g., meniscal tear).


img A preceding illness raises the possibility of the infectious trigger of JRA or postinfectious arthritis.


img Illness onsets with a history of enteritis raise the possibility of reactive arthritis.


img History of travel with exposure to ticks raises the possibility of arthritis caused by Lyme disease.


img Gastrointestinal symptoms raise the possibility of inflammatory bowel disease.


img Very severe joint pain raises the possibility of acute rheumatic fever (also suggested by migratory but not additive arthritis, with fevers), acute lymphocytic leukemia (with metaphyseal pain on examination and a decrease in two or more cell lines), septic arthritis, or osteomyelitis.


img Weight loss without diarrhea may be observed in individuals with active JRA and is sometimes associated with anorexia. This symptom is also observed in individuals with acute lymphocytic leukemia with other obvious findings (e.g., severe bone pain).


img Weight loss with diarrhea may be observed in persons with inflammatory bowel disease.


img Photophobia may be observed in persons with usually asymptomatic uveitis.


img Orthopnea suggests pericarditis in children with systemic JRA; the differential diagnosis includes systemic lupus erythematosus (SLE) and viral pericarditis.


img Systemic-onset JRA is characterized by spiking fevers, typically occurring several times each day, with temperature returning to the reference range or below the reference range.


img Systemic-onset JRA may be accompanied by an evanescent rash, which is typically linear, affecting the trunk and extremities.


img Arthralgia is often present. Frank joint swelling is atypical; arthritis may not occur for months following onset, making diagnosis difficult.


img The pauciarticular disease is characterized by arthritis affecting four or fewer joints.


img Typically, larger joints (e.g., knees, ankles, and wrists) are affected.


img Monoarticular arthritis in a hip is highly unusual.


img When the knee is affected, limping may be noted, particularly in the mornings.


img The polyarticular disease affects at least five joints.


img Both large and small joints can be involved, often in symmetric bilateral distribution.


img Severe limitations in motion are usually accompanied by weakness and decreased physical function.


img Some children may have a generalized myalgia.


img Localization to the proximal muscles raises the possibility of a myositis.


img Consider slipped capital femoral epiphysis (SCFE) or chondrolysis of the hip in an older child, or osteomyelitis, Legg–Calvé–Perthes disease, toxic synovitis of the hip, or septic arthritis in the younger child.


Chronic involvement can result in atrophy of extensor muscles in the thigh, tight hamstring muscles, and knee flexion contractures.


A detailed physical examination by a physician is a critical tool for diagnosing JRA to help rule out other causes.


Intervention

Physical therapists are essential members of the rheumatology team that includes the rheumatologist, nurse, occupational therapist, ophthalmologist, orthopaedist, and pediatrician.24 Other specialists, including cardiologists, dermatologists, orthotists, psychologists, and social workers, provide occasional consultation as needed. The physical therapy examination is performed to determine the relationship between the impairments and observed or reported activity restrictions. The plan of care (POC) is designed to reduce current impairments, maintain or improve function, prevent or minimize secondary problems, and provide education and support to the child and family. Specific interventions can include any or all of the following:



img ROM and stretching exercises.


img Acute stage: passive and active assisted exercises to avoid joint compression.


img Subacute/chronic stages: active exercises.



img Strengthening: avoid substitutions, minimize instability, atrophy, deformity, pain, and injury.


img Acute and subacute stages: isometric exercises are progressed cautiously to resistive.


img Chronic stage: concentric exercises.



img Endurance exercises: encouraging exercise by using fun and recreational activities, swimming.



img Joint protection strategies and body mechanics education.


img Mobility assistive devices.


img Rest, as needed—balance rest with activity by using splinting (articular resting).


img Posture and positioning to maintain joint ROM.


img Patients should spend 20 minutes/day in the prone position to stretch the hip and knee flexors


img Avoidance of high-impact activities.


img Assess leg-length discrepancy in standing and avoid scoliosis.



img Therapeutic modalities for pain control.


img Instructions on the wearing of warm pajamas, sleeping bag, electric blanket.


Idiopathic Scoliosis



The overall contour of the normal vertebral column in the coronal plane is straight. In contrast, the contour of the sagittal plane changes with development (see Chapter 22).25–30 Scoliosis represents a progressive disturbance of the intercalated series of spinal segments that produces a three-dimensional deformity (lateral curvature and vertebral rotation) of the spine. Despite an extensive amount of research devoted to discovering the cause of idiopathic scoliosis, the mechanics and specific etiology are not clearly understood, hence the name. It is known, however, that there is a familial prevalence of idiopathic scoliosis.


Clinical Findings

Using the James classification system, scoliosis has three age distinctions. These distinctions, though seemingly arbitrary, have prognostic significance.



img Infantile idiopathic. Children diagnosed when they were younger than 3 years, usually manifesting shortly after birth. Although 80–90% of these curves spontaneously resolve, many of the remainders of cases will progress throughout childhood, resulting in severe deformity. In the most common curve pattern (right thoracic), the right shoulder is rotated anteriorly, and the medial border of the right scapula protrudes posteriorly.


img Juvenile idiopathic. Children diagnosed when they are 3–9 years. This type is found more frequently in girls than boys, and individuals that develop this condition are generally at a high risk for progression to more severe curves.


img Adolescent idiopathic. Manifesting at or around the onset of puberty and accounting for approximately 80% of all cases of idiopathic scoliosis.


The following are the main factors that influence the probability of progression in the skeleton of the immature patient:



img The younger the patient at diagnosis, the greater the risk of progression.


img Double-curve patterns have a greater risk for progression than single-curve patterns.


img Curves with greater magnitude are at a greater risk to progress.


img The risk of progression in females is approximately 10 times than that of males with curves of comparable magnitude.


img Greater risk of progression is present when curves develop before menarche.

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Dec 27, 2016 | Posted by in ORTHOPEDIC | Comments Off on Special Populations
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