DEVELOPMENTAL DYSPLASIA OF THE HIP
Developmental dysplasia of the hip (DDH) is an abnormal development or dislocation of the hip joint present from birth.
DDH can be unilateral or bilateral. It affects the left hip more often (67%) than the right. This abnormality occurs in three degrees of severity:
dislocatable — hip positioned normally but manipulation can cause dislocation
subluxatable — femoral head rides on edge of acetabulum
dislocated — femoral head totally outside the acetabulum.
Unknown, but genetic factors may play a role.
Breech delivery (malposition in utero; DDH is 10 times more common with breech delivery than after cephalic delivery)
Elevated maternal relaxin
Large neonates and twins (more common)
DDH may be related to trauma during birth, malposition in utero, or maternal hormonal factors. For example, the hormone relaxin, secreted by the corpus luteum during pregnancy, causes relaxation of pubic symphysis and cervical dilation; excessive levels may promote relaxation of the joint ligaments, predisposing the infant to DDH. Also, excessive or abnormal movement of the joint during a traumatic birth may cause dislocation. Displacement of the bones within the joint may damage joint structures, including articulating surfaces, blood vessels, tendons, ligaments, and nerves. This may lead to ischemic necrosis because of the disruption of blood flow to the joint.
DDH is the most common cause of secondary osteoarthritis (Uchida et al., 2016)
Degenerative hip changes
Soft tissue damage and labral tears
Signs and Symptoms
In neonates: no gross deformity or pain
Young patients typically complain of groin pain associated with intra-articular pathological abnormalities (Uchida et al., 2016).
Many young patients also have lateral hip pain due to fatigue of structures such as the iliotibial band (Poultsides et al., 2012).
Complete dysplasia: Hip rides above the acetabulum, causing the level of the knees to be uneven.
Limited abduction on the dislocated side as the growing child begins to walk
Swaying from side to side (“duck waddle”)
Asymmetry of the thigh fat folds
Positive Ortolani’s sign
Positive Trendelenburg’s sign
Eliciting Ortolani’s Sign
Place infant on his back, with hip flexed and in abduction. Adduct the hip while pressing the femur downward. This will dislocate the hip.
Then, abduct the hip while moving the femur upward. A click or a jerk (produced by the femoral head moving over the acetabular rim) indicates subluxation in a neonate younger than 1 month. In the older infant, the sign indicates subluxation or complete dislocation.
Eliciting Trendelenburg’s Sign
When the child stands on the involved limb and lifts his other knee, the pelvis drops on the uninvolved side because the abductor muscles in the affected hip are weak.
However, when the child stands with his weight on the uninvolved side and lifts the other knee, the pelvis remains horizontal.
Diagnostic Test Results
X-rays show the location of the femoral head and a shallow acetabulum (also used to monitor disease or treatment progress).
Sonography and magnetic resonance imaging (MRI) assess reduction.
Infants Younger Than Age 3 Months
Reduce dislocation — gentle manipulation
Maintain reduction — splint brace or harness worn for 2 to 3 months to hold the hips in flexed and abducted position
Tighten and stabilize joint capsule in correct alignment — night splint for another month
Beginning at Ages 3 Months to 2 Years
Try to reduce dislocation — gradual abduction of the hips with bilateral skin traction (in infant) or skeletal traction (in child who is walking)
Maintain immobilization — Bryant’s traction or divarication traction for 2 to 3 weeks (with both extremities in traction, even if only one is affected), for children weighing less than 35 lb (16 kg)
If traction fails — gentle closed reduction under general anesthesia to further abduct the hips, followed by spica cast for 4 to 6 months
If closed treatment fails or in hips showing poor acetabular remodeling after closed reduction, surgery is indicated including open reduction and immobilization in spica cast for an average of 6 months or surgical division and realignment of bone (osteotomy) (Shin et al., 2016).
Beginning at Ages 2 to 5
Skeletal traction and subcutaneous adductor tenotomy (surgical cutting of the tendon)
Muscular dystrophy is a group of congenital disorders characterized by progressive symmetric wasting of skeletal muscles without neural or sensory defects. Paradoxically, some wasted muscles tend to enlarge (pseudohypertrophy) because connective tissue and fat replace muscle tissue, giving a false impression of increased muscle mass. The prognosis varies with the form of disease. The four main types of muscular dystrophy include:
Duchenne’s or pseudohypertrophic (50% of all cases) — strikes during early childhood, is usually fatal during the second decade of life, and affects 13 to 33 per 100,000 persons, mostly males
Becker’s or benign pseudohypertrophic (milder form of Duchenne’s) — becomes apparent between ages 5 and 15, is usually fatal by age 50, and affects 1 to 3 per 100,000 persons, mostly males
Facioscapulohumeral (Landouzy-Dejerine) and limb-girdle — usually manifests in second to fourth decades of life, doesn’t shorten life expectancy, and affects both sexes equally.
Genetic Mechanisms, Typically Causing an Enzymatic or Metabolic Defect
Duchenne’s or Becker’s muscular dystrophy — X-linked recessive disorders; mapped to the Xp21 locus for the muscle protein dystrophin, which is essential for maintaining muscle cell membrane; muscle cells deteriorate or die without it
Limb-girdle muscular dystrophy — autosomal recessive disorder
Facioscapulohumeral muscular dystrophy — autosomal dominant disorder
Abnormally permeable cell membranes allow leakage of a variety of muscle enzymes, particularly creatine kinase. The metabolic defect that causes the muscle cells to die is present from fetal life onward. The absence of progressive muscle wasting at birth suggests that other factors compound the effect of dystrophin deficiency. The specific trigger is unknown, but phagocytosis of the muscle cells by inflammatory cells causes scarring and loss of muscle function.
As the disease progresses, skeletal muscle becomes almost totally replaced by fat and connective tissue. The skeleton eventually becomes deformed, causing progressive immobility. Cardiac muscle and smooth muscle of the GI tract typically become fibrotic. The brain exhibits no consistent structural abnormalities.
Signs and Symptoms
Insidious onset between ages 3 and 5
Initial effects on legs, pelvis, shoulders
Enlarged, firm calf muscles
Delay in motor development and skeletal muscle weakness
Waddling gait, toe walking, and lumbar lordosis
Difficulty climbing stairs
Positive Gower’s sign — patient stands from a sitting position by “walking” hands up legs to compensate for pelvic and trunk weakness
Becker’s (Benign Pseudohypertrophic)
Similar to those of Duchenne’s type but with slower progression
Weak face, shoulder, and upper arm muscles (initial sign)
Pendulous lip and absent nasolabial fold
Abnormal facial movements; absence of facial movements when laughing or crying
Inability to raise arms above head
Weakness in upper arms and pelvis (initial sign)
Lumbar lordosis, protruding abdomen
Winging of scapulae
Waddling gait, poor balance
Inability to raise arms
Diagnostic Test Results
Electromyography shows short, weak bursts of electrical activity in affected muscles.
Muscle biopsy shows a combination of muscle cell degeneration and regeneration (in later stages, showing fat and connective tissue deposits).
Immunologic and molecular biological techniques facilitate accurate prenatal and postnatal diagnosis of Duchenne’s and Becker’s muscular dystrophies.
Coughing and deep-breathing exercises
Teaching parents to recognize early signs of respiratory complications
Orthopedic appliances, physical therapy, possible wheelchair prescription
Surgery to correct contractures
Adequate fluid intake, increased dietary bulk, stool softener
Low-calorie, high-protein, high-fiber diet
Osteomyelitis is a bone infection characterized by progressive inflammatory destruction after the formation of new bone. It commonly results from a combination of local trauma — usually trivial but causing a hematoma — and an acute infection originating elsewhere in the body. Although osteomyelitis usually remains localized, it can spread through the bone to the marrow, cortex, and periosteum.
Osteomyelitis is usually classified as acute if symptoms have been present for less than 2 weeks, subacute between 2 weeks and 3 months, or chronic if greater than 3 months (Chiappini et al., 2016).
Acute osteomyelitis is usually a blood-borne disease and most commonly affects rapidly growing children, with an estimated incidence of 8 cases per 100,000 children/year and a male:female ratio of 2:1. The long bones, such as the femur, are the most frequently involved and the lower extremities are more affected than the upper extremities (Yeo & Ramachandran, 2014). Although rare, with chronic osteomyelitis, drainage of the sinus tracts may be necessary and widespread lesions may be present. Possible consequences may include amputation of an arm or leg when resistant chronic osteomyelitis causes severe, unrelenting pain and decreased function due to weakened bone cortex.
Osteomyelitis occurs more often in children (especially boys) than in adults — usually as a complication of an acute localized infection. The most common sites in children are the distal femur and the proximal tibia, humerus, and radius. The most common sites in adults are the pelvis and spinal vertebrae, usually after surgery or trauma.
The incidence of osteomyelitis is declining, except in drug abusers. With prompt treatment, prognosis is good for acute osteomyelitis but remains poor for chronic osteomyelitis.
Minor traumatic injury
Acute infection originating elsewhere in the body
Staphylococcus aureus (most common)
Pasteurella multocida (part of normal mouth flora in cats and dogs)
Typically, a pathogen finds a culture site in a hematoma after recent trauma or in a weakened area, such as the site of a local infection (for example, furunculosis). It then travels through the bloodstream to the metaphysis, the section of a long bone that is continuous with the epiphysis plates, where the blood flows into sinusoids. Pus is produced and pressure builds in the rigid medullary cavity. An abscess forms and the bone is deprived of its blood supply. Necrosis results and new bone formation is stimulated. The dead bone detaches and exits through an abscess of the sinuses resulting in chronic osteomyelitis.
Signs and Symptoms
Sudden pain and tenderness in the affected bone is present approximately 81% of the time (Dartnell et al., 2012).
Swelling and erythema are present approximately 70% of the time (Dartnell et al., 2012).
Decreased ability to bear weight through the affected bone
Restricted movement of the surrounding soft tissues
Chronic infection may present intermittently for years, flaring after minor traumas or persisting as drainage of pus from a pocket in a sinus tract.
Fever is present approximately 61% of the time in children (Dartnell et al., 2012).
Chills, nausea, and malaise
Drainage of pus
Diagnostic Test Results
White blood cell (WBC) count and erythrocyte sedimentation rate (ESR) are elevated.
Blood cultures show causative organism.
X-ray may not show bone involvement until disease has been active for 2 to 3 weeks.
MRI delineates bone marrow from soft tissue.
Bone scans detect early infection.
Immobilization of the affected body part by cast, traction, or bed rest
Supportive measures, such as analgesics for pain and I.V. fluids to maintain hydration
Incision, drainage, and culture of an abscess or sinus tract Acute Infection
Intracavitary instillation through closed system continuous irrigation with low intermittent suction
Limited irrigation; blood drainage system with suction (Hemovac)
Packed, wet, antibiotic-soaked dressings
Primary malignant bone tumors (also called sarcomas of the bone and bone cancer) are rare, and while constituting only 1% of new cancer diagnoses, it accounts for 2% of cancer deaths (Zhang et al., 2016). The incidence is approximately 8 cases per million/year (Aggerholm-Pedersen et al., 2014). Most bone tumors are secondary, caused by seeding from a primary site.
Rapid bone growth — Children and young adults with primary bone tumors are much taller than average.
Bone tumors are growths of abnormal cells in bones. These abnormal cells divide uncontrollably and healthy tissue is replaced with unhealthy tissue. Bone tumors may originate in osseous or nonosseous tissue. Osseous bone tumors arise from the bony structure itself and include osteogenic sarcoma (the most common), parosteal osteogenic sarcoma, chondrosarcoma, and malignant giant cell tumor. Nonosseous tumors arise from hematopoietic, vascular, or neural tissues and include Ewing’s sarcoma, fibrosarcoma, and chordoma.
Signs and Symptoms
Bone pain (most common indication of primary malignant bone tumors). Characteristics include the following:
greater intensity at night
usually associated with movement
dull and usually localized
may be referred from hip or spine and result in weakness or a limp.
Tender, swollen, possibly palpable mass
Cachexia, fever, and impaired mobility in later stages
Diagnostic Test Results
Incisional or aspiration biopsy confirms cell type.
Bone X-rays, radioisotope bone scan, and computed tomography (CT) scan reveal tumor size.
Flourine-18-fluorodeoxyglucose positron emission tomography (F-FDG PET) and PET/CT can be applied to differentiate primary bone sarcomas from benign lesions (Liu et al., 2015).
PET/CT is useful for the diagnosis, staging, restaging, and recurrence surveillance of bone sarcomas (Liu et al., 2015).
Blood studies reveal hypercalcemia and elevated alkaline phosphatase.
Independent adverse prognostic factors for survival include increasing age, tumor size, metastasis, soft tissue involvement, high grade, and intralesional/marginal excision or not having surgery (Aggerholm-Pedersen et al., 2014).
Scoliosis is a lateral curvature of the thoracic, lumbar, or thoracolumbar spine. The curve may be convex to the right (more common in thoracic curves) or to the left (more common in lumbar curves). Rotation of the vertebral column around its axis may cause rib cage deformity. Scoliosis may be associated with kyphosis (humpback) and lordosis (swayback).
About 2% to 3% of adolescents have scoliosis. In general, the greater the magnitude of the curve and the younger the child at the time of diagnosis, the greater the risk for progression of the spinal abnormality. Optimal treatment usually achieves favorable outcomes.
Scoliosis may be functional (a reversible deformity) or structural (fixed deformity of spinal column). The most common curve in functional or structural scoliosis arises in the thoracic segment, with convexity to the right. As the spine curves laterally, compensatory curves (S curves) with convexity to the left develop in the cervical and lumbar segments to maintain body balance. Idiopathic scoliosis, the most common type of structural scoliosis, varies according to age at onset, as follows:
infantile — affecting mostly male infants between birth and age 3, infantile scoliosis comprises less than 1% of all cases of idiopathic scoliosis in the Unites States. The majority of curves tend to be left sided and may be associated with other congenital anomalies (Riseborough & Wynne-Davies, 1973)
juvenile — affects both sexes between ages 4 and 10; no typical curvature
adolescent — generally affects girls between age 10 and skeletal maturity; no typical curvature.
Uneven leg length
Congenital — wedge vertebrae, fused ribs or vertebrae, and hemivertebrae
Paralytic or musculoskeletal — asymmetric paralysis of trunk muscles due to polio, cerebral palsy, or muscular dystrophy
Idiopathic — most common; appears in a previously straight spine during the growing years; may be transmitted as an autosomal dominant or multifactorial trait
Differential stress on vertebral bone causes an imbalance of osteoblastic activity. The vertebrae rotate, forming the convex part of the curve. The rotation causes rib prominence along the thoracic spine and waistline asymmetry in the lumbar spine.
Severe deformity (if untreated)
Major thoracic deformity before the age of 5 is associated with twice the mortality rate due to compromised cardiopulmonary system (Alsiddiky, 2015).
Cor pulmonale (curvature greater than 80 degrees)
Signs and Symptoms
Lower back pain
Uneven hemlines or pant legs that appear unequal in length
Apparent discrepancy in hip height
Unequal shoulder heights, elbow levels, and heights of iliac crests
Asymmetric thoracic cage and misalignment of the spinal vertebrae when patient bends forward — commonly known as a rib hump
Asymmetric paraspinal muscles, rounded on the convex side of the curve and flattened on the concave side
Diagnostic Test Results
Anterior, posterior, and lateral spinal X-rays, taken with the patient standing upright and bending, confirm scoliosis and determine the degree of curvature and flexibility of the spine.
CT provides three-dimensional information that can allow evaluation of the curvature, thoracic cage, and lung volumes (Gollogly et al., 2004).
An MRI may be performed to further investigate underlying spinal anomalies (Pahys 2009).
Scoliosiometry measures the angle of trunk rotation.
Mild Scoliosis (Less Than 25 Degrees)
Observation — X-rays to monitor curve and re-examination every 3 months
Physical therapy and exercise to strengthen torso muscles and prevent curve progression
Moderate Scoliosis (30 to 50 Degrees)
Spinal exercises and a brace (may halt progression but doesn’t correct established curvature); braces can be adjusted as the patient grows and worn until bone growth is complete
Alternative therapy using transcutaneous electrical nerve stimulation (TENS) for pain
Severe Scoliosis (50 Degrees or More)
Surgery — supportive instrumentation; spinal fusion in severe cases
Physical therapy is often indicated after surgery to regain motion and improve trunk strength