Author
Norberto Alvarez, MD
Assistant Professor; Department of Neurology
Harvard Medical School
Consulting Staff; Department of Neurology
Boston Children's Hospital
Boston, Massachusetts
Disclosure: Norberto Alvarez, MD, has disclosed no relevant financial relationships.
Editor
Lars Grimm, MD, MHS
House Staff
Department of Internal Medicine
Duke University Medical Center
Durham, North Carolina
Disclosure: Lars Grimm, MD, MHS, has disclosed no relevant financial relationships.
Reviewer
Jose Varghese, MD
Associate Professor of Radiology
Boston University School of Medicine
Boston, Massachusetts
Disclosure: Jose Varghese, MD, has disclosed no relevant financial relationships.
Simply defined, limping is any deviation from a normal gait pattern. A child with a limp is a common presentation to clinicians. Although many etiologies are benign, clinicians must remain suspicious for more serious causes, such as inflammatory, structural, infectious, malignant, neurologic, and rheumatologic conditions. This "frog-leg" plain x-ray of the pelvis demonstrates a slipped capital femoral epiphysis (SCFE) of the left femoral head (arrow) in an adolescent with complaints of thigh and knee pain.
A septic joint is the result of hematogenous spread of infection to the joint, resulting in pus formation and fluid distension. This is a pediatric emergency because significant joint damage can occur within hours of infection. The most common organism causing septic joint is Staphylococcus aureus, followed by meningococci, Escherichia coli, Klebsiella species, and Enterobacter species. Gonococcal arthritis can be acquired in newborns at the time of delivery, in teenagers who are sexually active, and in children who have been sexually abused. This image is an emergency room photograph of an infant with septic arthritis of the left hip who is holding his hip rigidly in the classic position of flexion, abduction, and external rotation. This position maximizes capsular volume; the patient is relatively comfortable as long as the hip joint remains immobile.
The natural history of inadequately treated septic arthritis can be devastating. The x-ray on the left is from a 22-month-old child with left hip pain for 1 week, showing no gross abnormality. The x-ray on the right was taken 3 weeks after and shows soft-tissue swelling, lateral hip dislocation, indistinctness of the growth plate, and considerable periosteal reaction of the proximal femoral shaft, characteristic of an associated osteomyelitis.
Follow-up films from the same patient are shown, demonstrating the natural history of septic arthritis. The film on the left, from 5 months after onset of infection, shows complete resorption of the femoral head and regeneration of the femoral shaft. The film on the right, from 9 years after onset of infection, shows destruction and deformity of the left hip. There is also superior subluxation of the femoral shaft with pseudoarticulation, resulting in profound limb-length discrepancy.
Transient synovitis is the most common cause of acute hip pain in children aged 3-10 years. This is a self-limited nonspecific inflammation of the synovium of the hip. The cause is unknown, and many children have a history of acute infection (eg, upper respiratory tract, otitis media) preceding the synovitis. The child may present with tenderness and/or pain in the hip and decreased motion with antalgic positioning of the hip. Without treatment, the symptoms subside in approximately 1 week. Nonsteroidal anti-inflammatory drugs can shorten the process to 2-3 days. The x-ray shown here demonstrates widening of the joint spaces (arrows), more prominent on the left, consistent with transient synovitis. A discrepancy of > 1 mm in width indicates the presence of fluid.
SCFE is the most common hip abnormality presenting in adolescents and has a male preponderance. Obesity is a major risk factor due to the increased shear forces placed on the proximal growth plate. The hips are often affected bilaterally. Patients may present with hip, thigh, or knee pain; acute or insidious limp; or decreased range of motion in the hip. Plain x-rays are usually adequate to make the diagnosis, demonstrating slippage of the femoral head off of the femoral neck (shown). Some of the common radiologic signs of SCFE include widening of the growth plate, loss of height of the epiphysis (the "setting sun" sign), and prolongation of the femoral neck (abnormal Klein's line). Early intervention is important to prevent avascular necrosis and is primarily operative internal fixation.
Osgood-Schlatter disease is one of the most frequent causes of knee pain in adolescents. The condition is probably related to repetitive trauma (as from chronic jumping or similar strenuous exercise) on a developing tibial tuberosity. This can lead to avulsion or fragmentation of the tibial tuberosity, heterotopic bone formation, thickening of the distal patellar tendon, and considerable soft-tissue swelling. Osgood-Schlatter disease presents with considerable focal pain and a palpable subcutaneous lump in the region of the tibial tuberosity. The condition is often seen in association with a rapid growth spurt. The x-ray on the left demonstrates fragmentation of the tibial tubercle (arrow) with overlying soft-tissue swelling, consistent with Osgood-Schlatter disease. The x-ray on the right demonstrates an enlarged tibial tubercle with an ossicle in a skeletally immature patient.
Developmental dysplasia of the hip is characterized by abnormal development of the acetabulum, femur, labrum, or capsule. The etiology is not clear, but factors like intrauterine position, ethnicity, genetics, musculoskeletal disorders, oligohydramnios, cerebral palsy, Ehlers-Danlos, and Marfan syndrome have all been associated with this condition. The classic diagnostic test is the Ortolani maneuver, in which the hip relocates after abducting pressure is applied to the legs with the hips flexed. This x-ray in a 1-year-old child demonstrates dislocation of the right hip, associated with a hypoplastic femoral capital epiphysis and malformed acetabulum.
Legg-Calvé-Perthes disease is osteonecrosis of the capital femoral epiphysis. It is a self-limited disease that affects 1 in 1200 children in the 5- to 10-year age range, with a median age of 7 years. It is 4-5 times more frequent in males and is usually unilateral. The cause is unclear but is probably related to the interruption of the blood supply to the femoral epiphysis. The x-ray shown here demonstrates flattening and early fragmentation of the left femoral head and presence of femoral neck cysts (arrow). The femoral head is also smaller on the left than on the right.
Childhood fractures are commonly seen as a consequence of accidents. The history of trauma may not be clear and the child may present with pain and gait disturbances. Initial x-rays may be normal, and only on follow-up x-rays may indirect signs of a fracture (eg, new bone formation) be evident. The x-ray shown here demonstrates a spiral fracture of the distal tibia with no involvement of the fibula. Two fracture lines are evident (black and white arrows). This type of fracture is seen in toddlers as a result of torsion of the foot.
Stress fractures and overuse syndrome are more common in adolescents and are related to intense physical activity. Repetitive loading of the lower extremities is an important factor in stress fractures. The tibia and the fibula are most commonly involved. The adolescent may complain of pain and have gait problems. In stress fractures, x-rays may be normal or show subtle changes. The x-ray shown here demonstrates a sesamoid fracture (arrow) in a 16-year-old female basketball player with pain and reduced weight bearing.
Tarsal coalition is a condition in which 2 or more bones in the midfoot or hindfoot are joined. The most common types of coalitions are those between the calcaneus and either the talus or the navicular bones. Patients with this congenital condition usually present during late childhood or adolescence, but presentations in adulthood have been reported. The condition usually presents as recurrent sprains and pain in the midfoot and has been associated with peroneal spastic flatfoot and fixed flatfoot. Early treatment usually involves conservative immobilization, while surgical intervention includes resection of the coalition or arthrodesis of degenerated painful joints. The plain x-ray on the left shows a calcaneonavicular coalition (arrow). The CT scan on the right demonstrates a talocalcaneal coalition (arrow).
Neuroblastoma is a solid tumor arising from embryonal cells. In most instances the primary is in the abdomen, but metastases are very frequent. Due to dissemination to the bones, one of the most common presentations is pain in the bones and a limping gait. The urine catecholamines, vanillylmandelic acid and homovanillic acid, are elevated in 90% of patients and are highly accurate for diagnostic purposes. The prognosis depends on the severity of dissemination. Localized neuroblastoma might have excellent prognosis with excision of the tumor. The outcome of patients with disseminated disease is poor. The x-ray shown demonstrates a permeative destructive lesion involving the proximal fibula (arrow), associated with periosteal reaction and soft-tissue mass due to metastatic neuroblastoma.
Osteosarcoma is a malignant tumor of the bones with a very poor prognosis. It is most common in adolescence and is the third most frequent cancer in this age group. Symptoms are related to the growth of the tumor and may be subtle in the beginning, often confused with growing pains or arthritis. Pathologic fractures are frequent complications. Systemic symptoms are uncommon. Osteosarcoma can occur in any bone, but there is preference for the femur, tibia, and humerus. When the tumor is in the lower extremities, the patient may present with a limping gait. The MRI shown demonstrates a well-defined, intermediate, high-signal intramedullary mass (arrow) compatible with osteosarcoma of the distal femur. There is high-signal edema surrounding the cortex of the distal femur. Surgery with removal of the lesion is the preferred treatment, and chemotherapy is indicated for metastatic disease.
Leukemias are neoplastic proliferations of white blood cells. The acute forms, especially the acute lymphoblastic leukemias, which are the most common in children, may present with bleeding, anemia, or infiltration of different organs. Infiltration of the bone marrow may present with bone pain or pathologic fracture. These frontal and oblique knee x-rays in a child with leukemia demonstrate lucent metaphyseal bands (arrows), a finding present in 90% of patients with leukemia.
Ewing sarcoma is a tumor thought to derive from cells of the neural crest. Translocation t (11;22) or one of a series of related translocations is present in more than 95% of these sarcomas. Ninety percent of the tumors are first diagnosed in early age, usually in the second decade. Ewing sarcoma frequently presents as localized painful mass. Tumors of the long bones may present with pathologic fractures. The x-ray on the left demonstrates an ill-defined permeative lytic lesion of the proximal femur with a lamellated periosteal reaction (arrows) in a 14-year-old boy with biopsy-proven Ewing sarcoma. The MRI on the right in the same patient demonstrates reactive bone marrow edema with a periosteal reaction and soft-tissue edema. Tumors that are localized have a survival rate of 70%; in those with metastatic disease, the survival rate is less than 25%.
Author
Norberto Alvarez, MD
Assistant Professor; Department of Neurology
Harvard Medical School
Consulting Staff; Department of Neurology
Boston Children's Hospital
Boston, Massachusetts
Disclosure: Norberto Alvarez, MD, has disclosed no relevant financial relationships.
Editor
Lars Grimm, MD, MHS
House Staff
Department of Internal Medicine
Duke University Medical Center
Durham, North Carolina
Disclosure: Lars Grimm, MD, MHS, has disclosed no relevant financial relationships.
Reviewer
Jose Varghese, MD
Associate Professor of Radiology
Boston University School of Medicine
Boston, Massachusetts
Disclosure: Jose Varghese, MD, has disclosed no relevant financial relationships.
Critical Findings on Plain Abdominal Radiographs
Foreign Body Sensation
Not-to-Miss Diseases Presenting as Hair Loss
Pediatric Rashes to Worry About
Sexually Transmitted Diseases (STDs), Definitive Diagnosis and Management
