Children often present to the ED with a limp. When there is a history of trauma, the management is often straight forward. Without a history of trauma, the differential can be overwhelming.
The causes of limping or leg pain in a child can be as benign as "growing pains" or as malignant as a tumor. To avoid a "shot gun" approach in the evaluation of a child with a non traumatic limp, the emergency physician should be knowledgeable in the history and physical examination findings of the common etiologies of the limping child to avoid unnecessary tests and radiographs. In this issue of Pediatric Emergency Medicine Practice, we will review the available evidence on the evaluation of a child with a non traumatic limp.
AP - Antero-posterior
CBC - Complete Blood Count
CRP - C Reactive Protein
CT - Computed Tomography
ED - Emergency Department
ESR - Erythrocyte Sedimentation Rate
HSP - Henoch Schonlein Purpura
JRA - Juvenile Rheumatoid Arthritis
LCPD - Legg-Calve-Perthes disease
MRI - Magnetic Resonance Imaging
NSAID - Nonsteroidal anti-inflammatory drug
ROC - Receiver Operator Characteristic
SCFE - Slipped Capital Femoral Epiphysis
WBC - White Blood Cell
While limping has been reported and studied for over 100 years,1 the past 10 years have yielded very little new literature in support of the ED approach to the diagnosis and treatment of limping. While there are several review articles discussing the evaluation and management of the child with a limp,2-12 there is a lack of methodologically sound studies examining this broad topic, specifically regarding the overall approach to the limping child. Most studies relate to the management of specific disorders once the diagnosis is already made. The key, of course, is getting to the correct diagnosis. In general, the history and physical examination will help narrow the focus in the extensive differential diagnosis and help guide the ED physician in the initial work-up and management.
Infections are common in this age group since the bony cortex is developing and there is little resistance to bacterial invasion. School-aged children are more ambulatory and rambunctious which increases their risk of injuries. Jumping off objects, such as bunk beds, trampolines, and trees can lead to injuries such as fractures, dislocations, and ligamentous injuries. In this age group, the bony architecture is more mature and resilient. Muscle strength has also increased dramatically. A SCFE is an example of how bone maturation, strength, and weight mismatches can result in problems.
Studies on septic arthritis and osteomyelitis have shown a tremendous decline in Haemophilus influenzab as a pathogen in pediatric septic arthritis in the late 1990's compared to the 1980's and earlier, largely due to widespread immunization programs.15,16 Most recent studies report Staphylococcus aureus as the predominant organism isolated in bacterial septic arthritis and osteomyelitis in all age groups, accounting for up to 53% of the cases.15-17 In Moumile's study, Kingella kingae was the second most common organism, occurring in 14% of the total isolates.17 This was followed by Streptococcus pyogenes and Streptococcus pneumoniae. In Luhmann's study, Staphylococcus aureus, Streptococcus pyogenes, and Enterobacter were the common organisms, followed by Kingella, Neisseria meningitides, Streptococcus pneumoniae, Neisseria gonnorhoeae, Candida, and Staphylococcus epidermidis.16 The pathogens involved may also exhibit some geographic variability. In a study conducted in Israel from 1988-1993, Kingella and Haemophilus influenza b were the two most common organisms isolated in patients less than 2 years of age with septic arthritis.18 Among neonates, Staphylococcus aureus remains the most common pathogen, followed by Escherichia coli and Group B Streptococcus.19 Salmonella was found to be the predominant organism causing osteomyelitis in patients with sickle cell disease, 20,21 though Staphylococcus aureus is also a common pathogen.
The type of limp can help determine the cause. Limps have been divided into three types: antalgic, trendelenburg, and short leg. The antalgic or "quick step" gait is a painful limp with a shorter stance on the affected or painful leg. It is commonly seen with traumatic injuries (fractures, sprains, or strains), tumors, or infectious etiologies. The Trendelenburg or "lurch gait" is a painless limp primarily due to musculoskeletal weakness. The affected hip drops down during the swing phase of the contralateral leg. The pelvis tilts into the affected side when standing. This may be seen with LCPD, SCFE, developmental dysplasia of the hip, and neuromuscular diseases (poliomyelitis). The developmental status of the child must be taken into consideration when assessing a gait disorder. Limping cannot be diagnosed until the infant can stand. Infants generally pull to a stand by nine months of age and start to "cruise" around while holding onto furniture or other items. Most children older than one year can walk unassisted. Toddlers initially have a wide-based gait. Intrinsic hip abductor weakness leads to a mild Trendelenburg gait and a noticeably shorter stance phase. By age three, children have assumed adult gait characteristics.
A more serious bone and joint infection can be easily missed and result in permanent sequelae if the diagnosis is delayed. Findings include swelling, erythema, and tenderness near the area of infection. Osteomyelitis in the pediatric population is commonly spread hematogenously. Staphylococcus aureus and Streptococcus pyogenes (group A beta-hemolytic streptococcus) constitute the major pathogens. In some circumstances, other pathogens need to be considered. Neonates are susceptible to group B Streptococcus and Escherichia coli, adolescents to Neisseria gonorrhea, and sickle cell patients to Salmonella.15-17,19-21 In addition to examining the involved extremity, a complete evaluation should include the spine and pelvis to rule out a diskitis or sacroiliac disease.
Transient synovitis may present in a similar manner to septic arthritis. It is a self-limited inflammation of the synovial lining, usually resolving within 3 to 10 days of the onset of symptoms. It is the most common cause of painful limp in childhood, accounting for up to 40% of non traumatic limps.14 Although the cause is unknown, it is hypothesized that transient synovitis is due to a post-infectious phenomenon. It often presents following a viral illness or upper respiratory infection.
Lyme disease, a tick-borne infection due to Borrelia burgdorferi, also includes arthritis as a characteristic feature. Lyme arthritis can be classified according to the number of joints involved and duration. Episodic arthritis involves 1 to 4 joints for a duration of <1 week with recurrence at least 2 weeks later. Acute and chronic pauciarticular arthritis involves 1 to 4 joints with chronic form lasting >4 weeks. The disease includes the typical expanding target lesion (erythema migrans), involvement of central and peripheral nervous systems, and migratory arthritis. Bilateral Bell's Palsy can be seen with Lyme disease.
The toddler's fracture is a spiral, oblique, non displaced fracture of the distal tibia, typically seen in children <3 years of age. Sometimes the fracture is only picked up on oblique views of the tibia, followup radiographs done weeks later, or by bone scan. Halsey et al found the most common symptoms of a toddler's fracture to be point tenderness and refusal to bear weight. The sensitivity and specificity of point tenderness (59% and 53%, respectively) and refusal to bear weight (82% and 30%, respectively) were found to be poor.25 In the same study, patients with a presumptive diagnosis of toddler's fracture were placed in a long leg cast or splint. However, 21 of the 59 patients did not have evidence of fracture even on follow-up x-rays. The final diagnosis in these patients is not known, and the inconvenience of taking care of a toddler in a long leg cast or splint is not discussed. Also, the question of what would have happened if these children were not splinted still remains unanswered.
Lower extremity fractures in non-ambulatory children should also raise suspicion for non-accidental trauma. Look for bucket handle fractures or corner fractures that are suggestive of child abuse. While spiral fractures are traditionally thought of as being suspicious for non-accidental trauma and are more likely to be investigated, they are not pathognomonic for abuse. Scherl et al found equal numbers of transverse and spiral femur fractures among cases with positive results of investigations for abuse.26 Mellick also found that isolated spiral tibial fractures are most commonly accidental.27 The history surrounding the event and other evidence of injury or neglect help determine whether child protective services investigation is warranted.
Primary malignant bony tumors such as osteosarcoma or Ewing's sarcoma commonly involve the long bones, and thus may be seen in the lower extremity. Growing children are affected most often, with the peak incidence occurring in the pre-teen and early teen years. Spinal tumors, such as sacrococcygeal teratoma or bony tumors of the axial skeleton may also cause lower extremity weakness, back pain, and limping.
Benign bone lesions such as osteochondromas and osteoid osteomas may be found in the limping child. Osteoid osteomas are a common benign bone tumor that may occur in the lower extremity or back, causing limping and pain. It is common in early adolescence, with pain characteristically worse at night, and relieved by NSAIDs. Radiographs usually confirm the diagnosis.
Osgood Schlatter's disease is characterized by pain over the tibial tuberosity. This disease is felt to be a result of repeated microtrauma to the insertion of the patellar tendon, similar to Sever's disease, which is pain in the area of the insertion of the Achilles tendon to the calcaneus. It is more common in adolescent boys, and may be bilateral 25-50% of the time.33 The diagnosis is made based on the presence of tenderness to palpation over the tibial tuberosity. In addition, pain is exacerbated with repeated activity, particularly jumping or knee extension against resistance. Resolution occurs when the secondary ossification center fuses to the proximal tibia, which occurs with maturation. Treatment consists primarily of limiting activity, immobilization, and NSAIDs.
SCFE is a medial or posterior slipping of the femoral capital epiphysis. The typical patient with SCFE is an overweight adolescent male. Manoff et al studied the association between body mass index and SCFE. They retrospectively reviewed 106 subjects with radiographically confirmed SCFE to 46 normal controls. In the SCFE group, 81.1% had a body mass index greater than the 95th percentile, compared to 41.3% in the control group (p< 0.0001).34 However, it is also seen in tall, thin adolescents who have undergone a recent growth spurt, resulting in shearing stress on the weakened epiphysis. SCFE will often present with a painful limp, hip or groin pain, or referred knee pain. Knee pain was found to be the primary presenting symptom in 15% of the patients with SCFE.35 Physical examination finds the hip externally rotated with painful range of motion, especially internal rotation, abduction, and flexion. Plain radiographs are generally the initial step in the diagnosis. Up to 60% of patients may develop bilateral SCFE, with about 23% having bilateral slips at the time of initial presentation. 36 There is also an association of SCFE with endocrine abnormalities such as hypothyroidism, panhypopituitarism, and hypogonadism. Such abnormalities should be suspected and evaluated in a younger child with SCFE, short stature, and hypogonadism. These children are also more likely to have bilateral SCFE.37 Adelay in diagnosis of SCFE results in increased slip severity and potentially higher risk of long-term complications.35 Treatment involves emergent orthopedic consultation for internal fixation.
Osteochondritis dissecans is a disease in which a small island of bone dies and is then sloughed. Typically, the child complains of poorly localized knee pain. Osteochondritis dessicans commonly presents in the preteen or early adolescent period. Pain with full flexion is usually found. If there is a piece of sloughed bone, one may find an effusion. Locking of the knee can occur while in flexion. Typically involving the distal femur, osteochondritis dessicans can be easily identified on plain AP radiographs of the femur. Treatment includes immobilization, isometric exercises to retain quadriceps tone, and pain control. Arthroscopic surgery is indicated for continued pain. (Please see the May 2006 issue of Pediatric Emergency Medicine Practice of pain management.)
Constitutional symptoms such as fever, pallor, easy bruising, chills, and weight loss with limping or bony pain should prompt an investigation for malignant causes of limping. Chronic limping or pain with a lack of other associated symptoms are more likely to occur with degenerative causes such as LCPD or SCFE. Also, a preceding illness such as an upper respiratory tract infection, pharyngitis, or scarlet fever is often noted with transient synovitis or post-infectious (post-strep) reactive arthritis. A history of abdominal pain, rash, travel history, or tick bite may also be useful in determining the etiology of the limp.
Evaluating lower extremity muscle bulk, strength, sensation, and deep tendon reflexes are also key aspects of the physical examination. Lack of deep tendon reflexes suggests Guillain-Barre syndrome, with limping due to weakness. Calf muscle hypertrophy may be seen with certain muscular dystrophies. The position that the legs are held in may also help localize the abnormality. For instance, patients with SCFE or LCPD often keep the affected hip externally rotated and slightly flexed. A positive Galleazzi test, with asymmetric knee heights with the patient supine, hips and knees flexed, is suggestive of developmental dysplasia of the hips. This test is more appropriate in an older child, as opposed to the Ortolani-Barlow maneuvers done on the neonate.
Local tenderness, masses, or swelling can be seen with osteomyelitis or bony tumors. Tenderness over the tibial tuberosity in an otherwise well child is diagnostic for Osgood Schlatter's disease. An evaluation of range of motion of the hips, knees, and back can also help localize the source of limping. Of course, observing the child's gait is a key part of the exam. The physician should determine if there is an antalgic gait, a Trendelenburg gait, or if it is actually ataxia, which would lead to an entirely different set of diagnostic considerations, such as cerebellar tumors. The child's shoes, socks, and, if possible, pants should be removed for the examination of gait.
The CBC may be useful when malignancy is high on the list of possible diagnoses for the patient. Thrombocytopenia, anemia, neutropenia, and/or evidence of blast cells on the peripheral smear certainly support the diagnosis of a malignancy. In addition, in a child in whom HSP is suspected, a CBC should be done to rule out thrombocytopenia as a cause of the purpura.
Several studies found a mean ESR among patients with septic arthritis to be approximately 50 mm/h.41, 43, 44 In a study of 26 patients, Klein reported a sensitivity of 91% for an ESR >30 mm/h, and 95% for an ESR >20 mm/h.44 However, specificities were not given. Del Beccaro et al showed an increased relative risk of 4.96 and 5.52 for having septic arthritis versus transient synovitis with an ESR of >20 mm/h and >30 mm/h, respectively. When calculating the relative risk of septic arthritis versus transient synovitis with an ESR of >20 mm/h and/or temperature >37.5 °C, the relative risk was found to be 22.48.39 However, in all these cases, the 95% confidence intervals were wide, likely due to the small sample sizes. In addition, Levine et al calculated an area under the ROC curve of 0.61 for ESR.45 Likelihood ratios for having septic arthritis did not have significant 95% confidence intervals with different ESR values, even with an ESR >75 mm/h. The ESR alone cannot make the diagnosis of septic arthritis, but may be useful in conjunction with other historical and examination findings that are suggestive of septic arthritis.
In a retrospective study on 278 children with multiple different etiologies of arthritis, Kunnamo found that a CRP of >2.0 mg/dL had a sensitivity of 94% and a specificity of 92% for the 18 patients with septic arthritis.47 Yet the positive predictive value was only 57%, with a negative predictive value of 99%. A higher CRP of >4.0 mg/dL had a lower sensitivity of 71%, but higher specificity of 98%. Levine et al found sensitivities of 41-90%, with specificities of 29-85%, depending on the cut-off value chosen.45 The area under the ROC curve for CRP was 0.72, compared with 0.61 for the ESR. This study also concluded that the CRP may be a better negative predictor than a positive predictor of septic arthritis, with a NPV of 87% if the CRP is <1.0 mg/dL.
LCPD is usually diagnosed by plain radiographs with AP and frog leg lateral views. Typically the radiograph shows sclerosis, flattening, or fragmentation of the femoral head. Early in the illness, a small femoral head with a possible widened medial joint space is seen, especially in comparison with the contralateral side. As the disease progresses, a crescentshaped radiolucent line, the crescent sign, appears along the proximal femoral head. Later in the diseases progression, the femoral head can become more radiopaque with subsequent fragmentation and collapse of the epiphysis. (See Figure 2). No recent studies have evaluated the diagnosis of LCPD. Instead, most studies have focused on outcome and management of LCPD by different radiographic methods including plain films, bone scan, ultrasound, CT, and MRI.54-60
The key to the diagnosis of SCFE is obtaining the appropriate radiographs and interpreting them correctly. Obtaining an AP view and a special frog leg lateral view is usually recommended because the AP view may fail to show the displacement in 14% of cases.61 (See Figure 3). Also, radiographs of bilateral hips can aid in the diagnosis with the unaffected hip serving as a comparison view. On an AP view, the "Klein line" is drawn along the lateral cortex of the femoral neck and should intersect a portion of the lateral femoral head. If it does not, then a medial slip of the femoral epiphysis is indicated. 62,63 (See Figure 4). Comparison to the contralateral hip may also reveal a smaller portion of the femoral head above the "Klein line" that can also suggest an early slip of the involved hip. On a frog leg lateral view, the slip may be more obvious. On a lateral view, if a line passing through the center of the femoral neck does not intersect the center of the femoral head, a posterior slip is suggested. A subtle finding of an early SCFE may be a physis that is widened or blurred (Bloomberg's sign) compared to the contralateral hip.64,65
Plain radiographs have a limited role in the emergent evaluation of septic arthritis. It has also been found to be unreliable for the diagnosis of a septic hip.66 In the presence of a widened joint space, the likelihood of septic arthritis is raised, but most plain radiographs are found to be normal even in the presence of a joint effusion. In a small retrospective study of children diagnosed with septic arthritis, Gandini showed that 12% of plain radiographs were found to be abnormal, in contrast to 83% of ultrasonographic studies showing an effusion. 67 Marchal also found that, of 21 children with transient synovitis, a joint effusion was detected on 20 patients with ultrasonography. But only 8 (42%) were found to have an increased joint space on plain radiographs.68
Most studies on ultrasonography have been focused on detecting an effusion in children with hip pain and septic arthritis. In a study conducted by Miralles, 500 children were prospectively evaluated by plain films and ultrasonography. Only 58 plain films were found to be abnormal when ultrasonography detected a hip effusion in 235 children.72 Gordon et al carried out ultrasonography in 132 children with hip pain. Follow up to determine the absence or presence of septic arthritis was conducted with 73 of the patients. Only four patients were found to have no effusion on initial ultrasonography but were later determined to have septic arthritis. Two had inadequate initial studies, and the other two had symptoms for <24 hours.73 Tien et al found 31 of 40 patients with suspected septic arthritis had an ultrasound confirmed joint effusion. Of these patients, 22 were found to have confirmed septic arthritis by needle aspiration of the joint.74
Another cause of hip effusions is transient synovitis. Marchal found that, of 21 children with transient synovitis, a joint effusion was detected on 20 patients with ultrasonography.68 Distinguishing between septic arthritis and transient synovitis is difficult as the two share many clinical and laboratory features. Several studies investigating the echogenicity of the effusion to differentiate septic arthritis from transient synovitis have had conflicting results. Dorr and colleagues found that 13 patients with confirmed septic arthritis had effusions on ultrasonography that were non-echofree. Of 58 patients with transient synovitis, 42 were echofree, 12 had a low level of echogenicity, and four had a very small amount of effusion that could not be classified confidently.75 In a prospective controlled study, Zieger also found that transient synovitis had effusions to be echofree, whereas septic arthritis showed non-echofree effusions. 76 In contrast, Marchal found increased echogenicity in the effusion of patients with transient synovitis, but no echogenicity in the one patient with a final diagnosis of septic arthritis.68 In 235 patients with a hip effusion, Miralles also found that no sonographic signs served to differentiate sterile, purulent, or hemorrhagic effusions.72 In an animal study of rabbits, Strouse et al demonstrated increased synovial vascularity in approximately 50% of septic arthritis cases by Doppler ultrasonography.77 In clinical practice, hypervascularity proved to be less useful showing only 1 of 11 patients with a positive finding on Doppler ultrasonography.78 Thus, while ultrasonography may be useful in detecting joint effusion, the specifics of the findings are conflicting and would be operator and viewer dependent.
Analgesic medication may include acetaminophen, NSAIDs, and narcotics, depending on the severity of the pain. In a randomized, blinded, placebo controlled study, Kermond et al found that NSAIDs shortened the duration of symptoms in children with a clinical diagnosis of transient synovitis of the hip.91
If a diagnosis of SCFE or LCPD is suspected, the patient should be non-weight bearing, and an urgent orthopedic referral should be made. Goals of therapy for LCPD include resolving the hip joint inflammation and positioning the femoral head in such a way as to promote healing. If 50% or more of the femoral head can be seen, therapy is aimed at maintaining the range of motion until healing occurs. When more than 50% of the head is involved, orthopedists will place the hip in an abduction brace or hip spica cast, or perform an osteotomy of the proximal femur to position the femoral head well into the acetabulum. Usually the brace is used for children under seven, and osteotomy reserved for the older patient. Ultimately, the outcome for those who present with less than 50% of their femoral head involved is good. Children under six do very well, but those over 10 or those with flattening of the femoral head do not. Treatment for SCFE involves in situ pinning to prevent further slippage.
The use of glucocorticoids has been studied for patients with HSP. In general, the routine use of prednisone in HSP is not recommended. Patientsmay be treated with steroids to relieve abdominal pain. However, Rosenblum and Winter showed that abdominal pain in patients with HSP is largely selflimited. 92 By 72 hours, there was no difference in the number of patients still complaining of abdominal pain between the group treated with prednisone and the group not treated with steroids. Huber et al conducted a randomized, placebo-controlled trial of prednisone in early HSP.93 They found no significant reduction in the risk of renal involvement or gastrointestinal complications with early prednisone therapy when compared to placebo. However, the total study population of 40 patients may be too small to detect relatively rare events such as intussusception. Mollica et al did find a significant difference in reduction of the development of nephropathy among patients with HSP.94 However, this study was not randomized or blinded. Most other studies are retrospective studies, with mixed results. Other studies have shown improvement in the progression of nephritis in more severe cases of HSP, where there is already evidence of significant nephropathy among patients treated with corticosteroids.95-97 The studies on the prevention of intussusception with the use of corticosteroids are generally limited by their retrospective nature and small number of patients.
Antibiotic therapy for suspected or proven infectious causes of limping such as osteomyelitis or septic arthritis should be guided by the age group, the common pathogens in the geographic area for that age group, and susceptibility patterns of the area. In general, therapy should include anti-staphylococcal coverage such as nafcillin, oxacillin, clindamycin, or vancomycin. Broader, gram-negative coverage with, for instance, a third-generation cephalosporin, may also be appropriate pending culture results.
In June 2003, an interdisciplinary expert committee in Boston set a clinical practice guideline for the treatment of septic arthritis of the hip in children to try to improve the process of care and the outcome of these children. They retrospectively reviewed the medical records of 30 children with septic arthritis as a control group and prospectively applied the clinical guideline in 30 consecutive patients seen at their hospital. The clinical guideline recommended that if a previously healthy patient between 6 months and 18 years of age is found to have a history and physical examination suggestive of a septic arthritis, the patient was to follow a set clinical guideline. Initial labs included CRP, ESR, CBC with differential, blood culture, throat culture and anti-streptolysin O antibody titers, along with radiographs of the hip. If the labs or radiographs suggested septic arthritis, then aspiration of the joint was done. However, the authors failed to define their laboratory or radiographic definitions for septic arthritis. If the joint aspirate showed WBC >50,000 /mm3 or a positive gram stain, then the patient was admitted for possible operative drainage or intravenous antibiotics. Once patients showed clinical improvement after 72 hours of treatment, they could be discharged home if able to tolerate oral antibiotics. Although this study showed a lower rate of bone scanning, lower rate of presumptive drainage, and a shorter hospital stay, there was no difference with outcome, readmission, or recurrent infection.98
Follow up studies of this clinical prediction rule have shown mixed results. In a follow up validation study by Kocher, applying the prediction rule prospectively to 51 patients with septic arthritis and 103 patients with transient synovitis revealed the same four predictors on multivariate analysis. Applying the algorithm with the same four predictors found the predicted probability of septic arthritis was 93.0% with four predictors, 72.85% with three predictors, 35% with two predictors, 9.5% with one predictor, and 2% with no predictor. The area under the receiver operating characteristic curve was 0.86. Although the clinical prediction rule did not perform as well as the initial study, they concluded that it maintained very good diagnostic performance in a new patient population.101
When applying the clinical algorithm to 163 patients, another validation study on a different study population found the four predictors proposed by Kocher had a predicted probability of a patient having septic arthritis of 59%, compared to the initial 99.6% published by Kocher.41,42
Some cases will require admission for further therapy and consultation. Among patients with suspected septic arthritis or osteomyelitis, the patient should be admitted for IV antibiotics, and, if needed, surgical drainage and debridement. In cases where pain is not adequately controlled with standard oral analgesics, admission for pain control and serial exams may be indicated. Suspected cases of neoplasm also warrant admission for further diagnostic evaluation, such as bone marrow biopsy or bony tumor biopsy. In addition, in traumatic cases where the history is not consistent with the injuries, and abuse is suspected, the child should be admitted for further investigation.
The differential diagnosis of patients who present to the ED with a complaint of a painful hip or a limp is extensive. Evaluating a child with a limp may be quite challenging if one does not use a systematic approach. The approach to narrowing the differental should begin with a thorough history and physical exam. When more serious conditions are suspected or cannot be ruled out, then further evaluation such as laboratory testing or further consultation is warranted. Selection of laboratory studies and imaging should be guided by the history and physical examination. Ultimately, the goal of the clinician is to exclude the more serious, life-threatening diseases and to prevent permanent impairment in function.
1. "I didn't think that a febrile child with a normal CBC could have a serious cause for his limp, so I discharged him home."
2. "Although the child with fever and pallor didn't have a source for his limp, an ESR was found to be elevated so I started him on steroids for a presumptive rheumatologic disease."
3. "The patient complained of knee pain and had a normal plain radiograph of the knee. Since he walked with a limp, I placed him in a knee immobilizer and discharged him home with instructions to follow up with his primary doctor within a week."
4. "The history was concerning for a hip disorder but the AP and lateral radiograph of the hips werefound to be normal."
5. "I did not want to get social work involved as the parents seemed genuinely concerned for their child. But in the presence of a spiral fracture to the tibia without a clear history, I called child protective services."
6. "I was uncertain whether this patient had transient synovitis or septic arthritis until an ESR wasfound to be 26 mm/h. Now I know he has septic arthritis."
7. "The child has sickle cell disease and fever with a limp. No obvious swelling was noted on examination, so I treated him with narcotics to manage his pain."
8. "I obtained a plain radiograph of the right hip due to pain and limping in an overweight male. I wassurprised to find it normal as I was highly suspicious of SCFE."
9. "The child had a limp with a normal examination. Since there was no focal area to radiograph, I discharged the patient home."
10. "I was considering a diagnosis of a septic hip in this patient, but since the plain radiographs showed no evidence of an effusion, I diagnosed her with transient synovitis."