Evaluation of Limp
Andrea Fang, MD
A 6-year-old boy with a 2-day history of right knee pain and limp is brought to the office. He has no history of knee trauma, swelling, redness, or associated fever. The medical history is unremarkable. The boy is afebrile, and his height and weight are at the 10th percentile for age. Examination of the right leg reveals decreased abduction and internal rotation of the hip; the knee is normal. The boy limps when he walks and favors his
1. What is the differential diagnosis of painful and painless limp in children?
2. What is the differential diagnosis of knee pain in children?
3. What laboratory tests and radiographic studies are indicated in the evaluation of children with limp?
4. What is the appropriate treatment of the child with a suspected infectious cause of limp?
A limp is a gait disturbance that occurs when an effort is made to minimize weight bearing on an affected leg to reduce pain and instability. The disturbance may be secondary to muscle weakness, deformity, pain, or a combination thereof. Muscle weakness may be caused by primary muscle disease, neurologic conditions, or disuse atrophy. Structural causes of limp include leg length discrepancy and joint stiffness, whereas painful causes of limp include trauma; synovitis; infection of bone, joint, or soft tissue; or neoplasm. A limp may be a sign of significant underlying disease, and accurate diagnosis and appropriate management are essential to prevent potentially serious morbidity.
A patient may limp because of pain originating in a leg or because of pain referred from the abdomen or spine. Age often defines the diagnostic possibilities; certain disorders are more common among particular age groups. Infectious causes of limp occur more frequently in infants and young children, and noninfectious causes are more common in school-age children and adolescents (Table 118.1).
Painful limp typically has an acute onset and may be associated with systemic signs, such as fever, especially when the etiology is infectious. The toddler may simply refuse to walk or walk with a slow, cautious gait when in pain rather than limp. Painless limp often has an insidious onset and is commonly caused by weakness (eg, muscular dystrophy) or deformity (eg, leg length discrepancy).
Normal gait has 2 phases: stance and swing. During the stance phase, both feet are on the ground as 1 heel strikes while the opposite foot moves to pre-swing; during the swing phase, 1 foot is not touching
the ground as the limb is moved forward. Stance phase is shortened in limp to decrease the amount of time spent bearing weight on the affected side or to minimize instability.
Normal adult gait is smooth and efficient, requiring the coordinated actions of the muscles of the legs and pelvis. Normal gait in children varies according to age and developmental maturity. The toddler typically walks with a broad-based, tiptoe, “bouncing” gait with the arms abducted for balance. A toddler may initiate the stance phase with either toe or heel strike. By 2 years of age, a child should initiate the stance phase consistently with heel strike. At 3 to 4 years of age, a child should exhibit normal adult gait with reciprocating arm swing most of the time.
Several types of abnormal gait are recognized. An antalgic gait has a characteristic shortened stance phase resulting from pain. Trendelenburg gait is caused by weakness of the hip abductors (eg, gluteus medius muscle) in which the pelvis dips down during stance phase, producing a swaying type gait. A tiptoe gait or toe-to-heel gait is normal in children for several months after they learn to walk. Persistence of such a gait beyond 2 years of age is abnormal, however, and may result from idiopathic heel cord contracture or contracture secondary to cerebral palsy.
Trauma is a frequent cause of limp in children and adolescents. In toddlers, a fall may not be witnessed, and they may present with limp or refusal to walk because of an occult fracture, such as toddler fracture (Figure 118.1). Toddler fracture is an oblique or spiral fracture of the middle or distal tibia that occurs after a fall or jump involving a twisting motion. Toddlers are at risk for such injuries because of their unsteady gait. Tpyically, standard anteroposterior (AP) and lateral radiographic views are obtained to determine if a fracture is present. The radiographic appearance may initially be normal, and oblique views may be helpful in visualizing the fracture. Follow-up radiographs or bone scanning may be necessary to make the diagnosis. The older child usually can recall a specific injury and localize pain to a specific area. In the patient with tenderness over an open growth plate, a splint should be applied and the patient should be closely followed even if radiographs appear normal because of the possibility for a Salter-Harris type I fracture, which occurs through the growth plate and may not be evident radiographically.
Abbreviations: DDH, developmental dysplasia of the hip; JIA, juvenile idiopathic arthritis; LCPD, Legg-Calvé-Perthes disease; SCFE, slipped capital femoral epiphysis.
Figure 118.1. Anteroposterior (left) and lateral (right) radiographs of toddler fracture evidenced by elevation of the periosteum.
Courtesy of Michael Diament, MD.
Painless limp in the toddler may be the result of developmental dysplasia of the hip, cerebral palsy, or leg length discrepancy (ie, anisomelia). As a result of developmental dysplasia of the hip, a child may have a Trendelenburg gait secondary to leg length discrepancy or to weakness of the hip abductors. Children with spastic cerebral palsy often walk on their toes because of increased tone or heel cord contracture. Functional or apparent leg length discrepancies may be the result of pelvic obliquity or spinal deformity. Children with true leg length inequality compensate by walking on tiptoe on the shorter side or bending the knee on the longer side. Limb discrepancies may be managed with orthoses (eg, heel lifts) for mild cases, whereas surgical lengthening or shortening procedures may be necessary for more severe cases.
Transient synovitis of the hip is a benign, self-limited inflammatory process involving the synovial lining and is among the most common causes of limp in the young child. The exact cause of the inflammation is not known. Although an association has been noted with certain upper respiratory infections, no infectious agent has been identified. Compared with the general population, children who were subsequently diagnosed with Legg-Calvé-Perthes disease (LCPD) have been noted to have a higher incidence of transient synovitis. This may be related to misdiagnosis or the historical use of traction to manage transient synovitis. Age of onset varies, but transient synovitis typically affects children 4 to 10 years of age, although it can present in younger or older persons. Males are affected at approximately twice the rate as females. Individuals usually present with acute onset of unilateral hip pain associated with a limp. A patient may experience referred pain to the anterior thigh or knee. Associated systemic symptoms, such as fever, are rare or absent and should prompt an investigation for another cause. A child may hold the leg in a position of abduction, flexion, and external rotation to reduce intracapsular pressure and associated pain. Symptoms are usually unilateral, but fewer than 10% of patients have bilateral involvement, often with 1 side more symptomatic than the other.
Transient synovitis is a diagnosis of exclusion and must be differentiated from more concerning diagnoses, such as septic arthritis. Consequently, laboratory evaluation typically consists of complete blood cell count (CBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Usually, the results are within normal limits or are slightly elevated. Radiographs are often obtained, which usually are normal or show signs suggestive of an effusion. Ultrasonography often is performed to evaluate for the presence of an effusion within the joint, which may occur with this condition. If arthrocentesis is performed, the fluid in transient synovitis usually has a white blood cell (WBC) count of less than 50,000/mm3 and a negative Gram stain. Individuals with normal laboratory values or with a fluid aspirate that is not suggestive of septic arthritis (when arthrocentesis has been performed) typically are managed with supportive care and close follow-up within 24 to 48 hours. Rest and nonsteroidal anti-inflammatory drugs (NSAIDs) are the mainstays of therapy. Nearly all children recover within 3 to 10 days with no significant sequelae. Recurrence rates can be as high as 69% within the first year of an episode of synovitis.
Septic arthritis occurs as the result of infection within the joint space. In children, this usually occurs in the setting of bacteremia, with hematogenous spread to the highly vascular synovial membrane. It can also occur from contiguous spread of an adjacent infection (eg, osteomyelitis) or by direct inoculation (eg, surgery, penetrating trauma). Staphylococcus aureus remains the most common pathogen identified across all age groups, with increasing incidences of community-acquired methicillin-resistant strains. Infants younger than 2 months also can be infected by neonatal pathogens, such as Streptococcus agalactiae (eg, group B streptococcus) and gram-negative enteric organisms (eg, Escherichia coli). Septic joints in children between 2 months and 5 years of age are usually caused by S aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Kingella kingae. Children older than 5 years usually have infections caused by S aureus or S pyogenes. Neisseria gonorrhoeae infections may be seen in sexually active adolescents. Historically, Haemophilus influenzae type b (Hib) was a common pathogen of osteoarticular infections in children; however, its incidence dropped dramatically after the introduction of the Hib vaccine.
Infants and children with septic arthritis often present with fever, decreased use of the affected extremity, limp, or refusal to walk. The most commonly affected joint is the hip, which is classically held in a position of abduction, flexion, and external rotation to reduce intracapsular pressure and associated pain. Passive range of motion typically elicits significant discomfort and resistance. Parents or caregivers of infants may notice increased crying with manipulation of the legs with activities such as diaper changing.
Subtle or early cases of septic arthritis often present a diagnostic challenge because of the potential for considerable clinical and laboratory overlap with transient synovitis. Unfortunately, no highly sensitive or specific laboratory test exists that can readily distinguish these 2 entities. Temperature higher than 38.5°C (101.3°F) was shown to be the single best predictor of septic arthritis in 1 study, with no children diagnosed with transient synovitis having a temperature above 38.5°C (101.3°F). Other predictors include refusal to bear weight, ESR greater than 40 mm/hour, a CRP greater than 2.0 mg/dL, and serum WBC count greater than 12,000/mm3. The presence of 1 of these 5 factors was associated with a probability of approximately 37% for having septic arthritis, whereas the presence of all 5 factors was associated with a probability of 98% for the condition. Imaging often consists of plain radiography and ultrasonography. Radiographs usually are nondiagnostic but may demonstrate joint space widening suggestive of an effusion. Ultrasonography usually demonstrates the presence of an effusion.
Analysis of synovial fluid remains the standard for the diagnosis of septic arthritis, and arthrocentesis of any effusion under sedation or anesthesia is indicated if a clinical suspicion of septic arthritis exists. A WBC count greater than 50,000/mm3 within the fluid aspirate generally is considered diagnostic for septic arthritis; however, elevated counts also occur with certain rheumatologic conditions. Regardless of WBC count, the presence of bacteria on Gram stain of joint aspirate is suggestive of infection. Routine cultures of joint aspirate as well as peripheral blood cultures should be obtained. Additionally, with the increasing recognition of K kingae as a causative agent in septic arthritis in young children, joint aspirations should be directly inoculated into blood culture bottles to enhance isolation because this organism is difficult to recover with standard culture techniques. In most studies, only approximately 50% of joint aspirate cultures grew out an identifiable pathogen. In 1 study, close to 50% of the aspirates that were sterile on standard culture media grew out K kingae from blood cultures. Other studies suggest sending a polymerase chain reaction assay, which is better for detecting K kingae, or a nasopharyngeal and throat culture, given this is often an area of colonization for patients with K kingae infection.
Joint damage from the purulent effusion can occur within 6 to 8 hours, which is why emergent evaluation and treatment is necessary. Complications occur in 10% to 25% of all cases of septic arthritis of the hip, and that rate increases in cases in which 5 days or more have passed before initiation of therapy. These complications include abnormal bone growth, permanent limp, unstable articulation of the affected joint, and decreased range of motion.
Osteomyelitis is an infection of the bone that typically is caused by a bacterial organism. Nearly 50% of pediatric cases of osteomyelitis occur in children younger than 5 years. Most cases of osteomyelitis in children occur from hematogenous deposition of bacteria into the bone marrow during a transient episode of bacteremia. Other cases may be the result of contiguous spread of an adjacent infection or direct inoculation. Osteomyelitis most commonly begins in the highly vascularized metaphysis of long bones of young children. The femur, tibia, and pelvis account for most cases. As with septic arthritis, S aureus remains the most common organism identified across all age groups, with an increasing incidence of methicillin-resistant S aureus (MRSA). Other organisms include S pyogenes, S pneumoniae, and K kingae. Young infants can also be infected by neonatal pathogens, such as group B streptococcus and enteric gram-negative organisms. Individuals with sickle cell disease (SCD) are at increased risk for infection with Salmonella. Haemophilus influenzae type b should also be considered in unvaccinated children.
Children often present with pain or localized symptoms at the affected site. More than one-half have a fever. Younger children may present with limp, reduced range of motion, or refusal to bear weight. In the setting of subperiosteal spread, erythema, warmth, and swelling may be evident at the affected site.
Laboratory tests can be supportive of a diagnosis of osteomyelitis but usually are not specific. Typically, a CBC, ESR, and CRP are obtained along with blood cultures. Leukocytosis may be present, but in more than one-half of cases, the WBC count is normal. Inflammatory markers are elevated in up to 90% of patients. A CRP greater than 10 mg/L (1.0 mg/dL) may also increase the suspicion for osteomyelitis complicated by septic arthritis. Blood cultures are positive in 40% to 55% of patients. Because of the importance of discerning the causative organism, the physician should consider ordering polymerase chain reaction assays for K kingae given its increasing incidence and difficulty to isolate. Radiographs are often normal or show only soft tissue changes early in the course of the disease. Periosteal reactions and lytic lesions rarely present before 10 to 21 days into the disease course. Bone scanning can be helpful in the preverbal child or in individuals who cannot localize their pain. Magnetic resonance (MR) imaging has become the study of choice, with a reported sensitivity of 97%. It is quite useful for distinguishing between bone and soft tissue infections.
Diskitis refers to an inflammatory process involving the intervertebral disks. This disease typically occurs in children younger than 5 years. It occurs almost exclusively in the lumbar region, causing progressive limp, back pain, and refusal to walk. Most children with the condition are afebrile. Diskitis is thought to occur in younger children because of the presence of vascular channels in the cartilaginous region of the disk space as well as abundant intraosseous arterial anastomoses. These vascular channels disappear with age. Laboratory studies are often nonspecific, with slight elevations in the peripheral WBC count and ESR. Radiographs are abnormal in 75% of patients, with decreased vertebral disk space and erosion of adjacent vertebral end plates being the most common abnormalities seen. Bone scanning demonstrates nonspecific increased marker uptake in the affected area. Computed tomography (CT) rarely provides a specific diagnosis and is not generally used. Magnetic resonance imaging demonstrates characteristic inflammatory changes and allows for differentiation from other conditions, such as vertebral osteomyelitis.
The exact etiology of diskitis is not known, and the treatment is somewhat controversial. Several authors propose that diskitis is the result of an infectious process and warrants antibiotic therapy. Others propose that it is simply a benign self-limited inflammatory disease because most cultures are sterile and patients can recover without any antimicrobial therapy. In most cases, broad-spectrum antibiotics and strategies to prevent kyphosis are initiated.
Legg-Calvé-Perthes disease is an idiopathic avascular necrosis of the femoral head. The exact etiology is unclear but involves some disruption in the vascular supply of the capital femoral epiphysis. The disease most commonly occurs in children 3 to 12 years of age (median age, 7 years), and it is 4 to 5 times as common in boys as in girls. The condition is bilateral in up to 15% of cases. Children typically present with a chronic intermittent limp that can be painful or painless. It is not uncommon for the child to be symptomatic for months before a diagnosis is made. Pain is usually worsened with internal rotation and abduction.
Laboratory tests are usually normal. Radiographs early in the course of the disease may be negative or show widening of the joint space. In later stages, radiographic findings include increased density and decreased size of the femoral head (ie, necrosis), patchy areas of radiolucency near the epiphysis (ie, fragmentation), and flattening of the femoral head (ie, reconstitution; Figure 118.2).
Slipped capital femoral epiphysis (SCFE) is a displacement or slipping of the femoral epiphysis from the neck of the femur through the open physis (ie, growth plate). This is the most common hip disorder affecting adolescents. It is more common in boys than girls and occurs more frequently among blacks and Hispanics than non-Hispanic whites. Typical age of onset is 9 to 16 years. Individuals often have overweight and frequently present with a chief symptom of knee pain. They often have an antalgic gait. The foot is externally rotated in severe slips but may be neutral or pigeon-toed in mild slips. Examination of the knee is normal without discomfort, despite the report of knee pain. Passive flexion of the hip often results in obligate external rotation. Typically, pain is elicited on internal rotation. With stable SCFE, the individual can walk with or without crutches; with unstable SCFE, walking is not possible. Laboratory testing is not indicated. Anteroposterior and batrachian (ie, frog-leg) radiographs of the hip are diagnostic in approximately 80% of patients. Early radiographic findings include widening of the physis, whereas slippage is noted radiographically later in the disease process (Figure 118.3). Imaging assessment of both hips is important because SCFE is bilateral in up to 20% of patients. When done by an experienced technician, ultrasonography has been shown to be an effective diagnostic tool, with a sensitivity of 95%. A slip can be visualized on CT or MR imaging; however, MR imaging is much more sensitive and can detect physeal widening in the pre-slip condition.
Osgood-Schlatter disease (OSD), or traction apophysitis of the tibial tubercle, is an overuse injury of the knee that occurs most commonly in adolescent athletes, particularly those who participate in running or jumping sports. Repetitive microtrauma causes partial avulsion of the patellar tendon at its insertion on the tibia. Individuals typically present with a localized bony prominence, swelling, and tenderness over the tibial tubercle at the insertion of the patellar tendon. Osgood-Schlatter disease can be diagnosed clinically, although radiographs are commonly obtained to rule out other pathology and typically demonstrate soft tissue swelling or edema of the skin and tissues, as well as ossific fragments within the tendon (Figure 118.4). Symptoms tend to resolve at approximately 14 to 15 years of age after the tibial tubercle closes.
Figure 118.2. Anteroposterior pelvic radiograph of a patient with Legg-Calvé-Perthes disease.
Courtesy of Michael Diament, MD.
Figure 118.3. Anteroposterior pelvic radiograph of a patient with slipped capital femoral epiphysis.
Courtesy of Michael Diament, MD.
Figure 118.4. Lateral radiograph of the knee in a patient with Osgood-Schlatter disease.
Courtesy of Michael Diament, MD.
A limp can also result from certain systemic disease processes, such as juvenile idiopathic arthritis, SCD, Lyme arthritis, and neoplastic disease. Juvenile idiopathic arthritis may involve multiple joints or have an associated rash. Evidence of inflammation (eg, warmth, swelling or effusion, redness) is typical (see Chapter 156). Usually, the pain is worst in the morning and improves throughout the day. Currently, SCD is detected on newborn screening, and most patients know of their diagnosis. Acute pain crises with SCD can affect multiple areas, resulting in significant discomfort, limp, and refusal to walk. Careful consideration for infectious etiologies (ie, osteomyelitis) is necessary in the highly febrile or ill child with SCD who presents with a limp or bone pain. Additionally, patients with SCD are at risk of avascular necrosis of the hip secondary to vasoocclusive episodes. Patients with Lyme arthritis typically are able to bear weight despite having a joint effusion, most commonly in the knee. A patient may have had earlier clinical symptoms of Lyme disease, such as the target-sign lesion, erythema chronicum migrans, or a viral prodrome. Other disseminated symptoms include meningitis, carditis, and cranial nerve palsy. Diagnosis can be made via enzyme-linked immunosorbent assay and Western blot. The arthritis usually is self-resolving but can be managed with antibiotics. Neoplastic disease processes, such as leukemia and primary bone tumors (eg, Ewing sarcoma, osteosarcoma) can present with bone pain and limp. The presence of pallor, petechiae, disseminated lymphadenopathy, or hepatosplenomegaly may be suggestive of leukemia. Peripheral CBC usually shows the presence of blasts and varying degrees of involvement of the various cell lines (ie, anemia, thrombocytopenia). Primary bone tumors may present with bony deformities or overlying soft tissue swelling. Characteristic bony lesions often are evident radiographically, although MR imaging may be necessary to ascertain the extent of involvement. Computed tomography may be necessary to assess for metastases. It may be necessary to refer a patient to an orthopedic surgeon for biopsy to ascertain a definitive diagnosis and for possible amputation. Referral to an oncologist is necessary to initiate appropriate therapy, including chemotherapy or radiation.
The history should focus on the time of onset of the limp, chronicity, and the resulting degree of disability. Often, a history of trauma is provided, even in the setting of a nontraumatic cause. Young toddlers often fall as they learn to walk, and parents and caregivers frequently relay some trivial or unrelated injury. Delayed motor development may be a sign of neuromuscular disease (eg, cerebral palsy), whereas a history of loss of motor milestones may be indicative of muscular dystrophy or spinal cord tumor. It is important to remember that pelvic pathology may be referred to the hip, and hip pathology is often referred to the knee or thigh.
Physical examination begins with observation for any overt deformity (eg, leg length discrepancy, joint swelling). All joints and the spine should be palpated, and the presence of swelling, tenderness, erythema, or warmth should be noted. A thorough evaluation of the hips is essential in the child with knee pain. The type of gait abnormality may be determined by observing the child walk or run.
The child should be examined supine and standing, if possible. The standing child can be assessed for pelvic obliquity and spinal deformities. Range of motion of the hips, knees, ankles, and feet can be assessed in the supine child, comparing the affected side with the nonaffected side. Muscle strength should be assessed, and leg length measurements should also be obtained as indicated. The child should be supine for a true measurement of leg length, which is the distance from the anterosuperior iliac spine to the medial malleolus. A discrepancy of more than 2 cm is considered significant in adults. The significance of discrepancies can be confirmed on imaging studies.
Laboratory studies are usually necessary in the child with an acute onset of limp with no clear trauma, especially in the child who refuses to bear weight or is febrile. Complete blood cell count, CRP, and ESR are useful markers of systemic disease and significant inflammation. Significant overlap may exist between the differing etiologies, and no single screening test can reliably distinguish between the various inflammatory and infectious causes of limp. Blood and local cultures (eg, joint fluid, bone) may be useful in the evaluation of suspected infectious entities. In addition to the culture, effusion studies should also include a cell count, Gram stain, glucose, and protein. Additional testing for rheumatologic causes may be clinically indicated, such as antinuclear antibody or rheumatoid factor (see Chapter 156).
Radiographs are the most commonly obtained images. At least 2 views should be obtained. For examination of the hip, both AP and batrachian views are necessary. It is important to include both hips in these images for comparison and to assess for the presence of bilateral disease. Ultrasonography is helpful if concern exists for an effusion within the joint space and can also be used to guide diagnostic and therapeutic interventions (eg, arthrocentesis) (Figure 118.5). Useful information is sometimes gleaned from CT, but MR imaging with gadolinium contrast is increasingly being used because of the superior resolution it affords and lack of radiation.
Figure 118.5. Ultrasound images of the hip. A, Anatomic landmarks in a hip ultrasound image illustrate normal joint space between the letters “A.” B, A normal hip joint space measuring 2.7 mm. Normal is less than 5 mm or a difference of less than 2 mm compared with the contralateral hip. C, A notable hip effusion with a joint space measuring 7.4 mm indicated by the dotted line and letter “A.”
Courtesy of Kathryn Pade, MD.
Management depends on the etiology. Management of septic arthritis consists of surgical drainage and intravenous (IV) antibiotics. Empiric therapy typically consists of an antistaphylococcal penicillin (eg, nafcillin sodium, oxacillin sodium). In a region with high rates of community-acquired MRSA, administration of clindamycin or vancomycin may be necessary until sensitivities can be performed. The addition of a third-generation cephalosporin is often indicated pending Gram stain and culture results to cover gram-negative pathogens, such as K kingae, or in cases in which N gonorrhoeae is suspected in an adolescent patient. Length of therapy typically consists of 2 to 4 weeks of IV antibiotics. Prognosis is generally good with prompt diagnosis and management within 4 days of symptom onset. Nonsteroidal anti-inflammatory drugs and low-dose steroids can also be considered to manage inflammatory pain.
Initial management of osteomyelitis also consists of IV antibiotics. Occasionally, surgery may be indicated, particularly in the setting of a subperiosteal or soft tissue abscess or sequestra. In communities in which methicillin-susceptible S aureus is more prevalent, empiric antibiotic therapy consists of an antistaphylococcal penicillin (eg, nafcillin sodium, oxacillin sodium) or a first-generation cephalosporin (eg, cefazolin). In areas in which community-acquired MRSA is of concern, clindamycin or vancomycin may be necessary. Neonates and individuals with SCD require the addition of a third-generation cephalosporin pending culture results. In individuals with a presumed pseudomonal infection, an extended spectrum β-lactam (eg, ceftazidime, cefepime, piperacillin/tazobactam) plus an aminoglycoside are indicated. Currently, 4 to 6 weeks of antibiotic therapy is recommended. Increasing data support switching to oral antibiotics after receiving as little as 2 to 4 days of parenteral therapy if compliance is likely, an organism has been identified, clinical improvement is noted, the patient is afebrile, and the inflammatory markers have begun to normalize. Oral dosages 2 to 3 times those normally recommended for nonosseous infections are often used for β-lactam antibiotics. Other oral antibiotics (eg, clindamycin, trimethoprim plus sulfamethoxazole, fluoroquinolone) have excellent bioavailability, and the usual oral dosages may be administered. Amoxicillin should be considered in children younger than 4 years who have not been vaccinated to cover H influenzae. Consultation with an infectious disease specialist is often indicated.
Supportive measures with NSAIDs are generally indicated for the management of diskitis. Broad-spectrum antibiotics are generally given, and the addition of anti-staphylococcal antibiotics should also be considered and have been shown to speed improvement of symptoms. A brace may be helpful for support and pain relief. Most patients recover without complications.
Prompt referral to an orthopedic surgeon is indicated in the patient with LCPD or SCFE. The goal of management of LCPD is to maintain full joint mobility and prevent femoral head deformity. Bed rest and immobilization decrease the pain and help restore range of motion. Traction and abduction casts or braces are used to contain the femoral head within the acetabulum in an effort to maintain its spherical shape. Surgical correction of gross deformities of the femoral head may be necessary in severe LCPD. Patients younger than 6 years are most likely to benefit from surgical treatment.
Management of SCFE consists of surgical reduction and stabilization with placement of screws through the epiphysis. The screws typically are left in place and do not need to be removed. Non-weight bearing is maintained until early callus is noted on the posteroinferior metaphysis and the pain has resolved. Gradual and progressive weight bearing is allowed, and progression to full weight bearing usually occurs 3 to 4 months after fixation. No running or jumping is allowed until the physis closes.
Treatment of OSD consists of rest, ice, NSAIDs, and strengthening exercises for the quadriceps and hamstring muscles. Surgical treatment is rarely indicated and is reserved for those patients who do not respond to nonsurgical therapy.
The prognosis depends on the etiology of the limp, time to diagnosis, and appropriate therapy.
In most cases of septic arthritis and osteomyelitis, the prognosis is good if the infection is diagnosed early and managed appropriately. The prognosis of osteomyelitis usually is good, with a less than 0.1% mortality rate and with less than 2% of patients who receive at least 3 weeks of antibiotic therapy developing chronic osteomyelitis. Management of chronic disease can be difficult, often necessitating prolonged courses of antibiotics (≤6–12 months) and multiple surgeries for débridement. Rare complications include disturbances in bone growth, leg length discrepancy, joint destruction, arthritis, abnormal gait, and pathologic fracture. Prognosis is also worse if treatment is delayed, the patient is younger, or the infection involves the hip, ankle, or knee. The main complication is degenerative arthritis of the hip. Regular follow-up with an orthopedic surgeon is necessary during the first year after diagnosis.
The prognosis of LCPD is related to the degree of femoral head involvement and age at onset of the disease. Children younger than 6 years have the best prognosis. The risk for developing degenerative arthritis in adulthood increases in children whose disease is more extensive and whose condition is diagnosed later (ie, after 8 years of age).
Untreated SCFE has the potential for further slippage of the femoral head until the growth plate closes. Potential treatment-related complications of SCFE include chondrolysis of the femoral head and acetabulum, avascular necrosis, and fracture at the site of pin placement. Generally, the prognosis is good and is based on the degree of slippage. The main complication is the development of avascular necrosis of the femoral head, which typically results in degenerative hip disease later in life. Degenerative hip disease later in life occurs in up to 15% of patients with SCFE and is more common in unstable SCFE. Only 7% of patients with a moderate slip have a poor outcome, compared with 24% of patients with a severe slip.
In approximately 5% to 10% of patients, OSD may become chronic, with persistent swelling and tenderness. In such cases, the formation of an ossicle over the tibial tubercle may be evident radiographically; because of the possibility that surgical resection of the ossicle may be required, the patient should be referred to an orthopedic surgeon.
The child’s history and physical examination seem to be consistent with LCPD. The child’s knee pain is found to be secondary to hip pathology. The diagnosis may have been missed had the physician not examined the hips and noted the abnormality in range of motion. Anteroposterior and batrachian radiographs of the hips were obtained, which showed joint space widening. Orthopedic consultation was obtained, and hospitalization for bed rest and ensured immobilization were recommended.