As with Perthes disease, SCFE may present as a chronic, subacute, or acute limp with referred pain to the groin, thigh, or knee. The patient with SCFE often has severe pain with internal rotation of the affected hip and will hold the hip in obligatory external rotation if it is flexed. Patients unable to bear weight on the affected side have unstable SCFE.
All patients with SCFE should be made nonweight bearing on the affected hip to prevent further slippage of the epiphysis. Definitive treatment involves in-situ fixation of the femoral neck with the proximal femoral epiphysis. Close orthopedic follow up is essential as roughly 50% of children with unilateral SCFE will go on to develop SCFE in the contralateral hip. Long-term complications of SCFE include osteonecrosis, joint space narrowing, and osteoarthritis.14,15
Osgood-Schlatter Disease
Osgood-Schlatter disease is a relatively benign cause of limp that is thought to occur due to repetitive trauma to the secondary ossification center tibial tubercle. Over time, the strong pull of the quadriceps muscle group on the patellar tendon causes a chronic avulsion at the site of the patellar tendon insertion on the tibial tuberosity. It most commonly develops in early puberty from ages 9 to 14 years. Affected children develop tenderness over the tibial tuberosity that is made worse with activity. On examination, pain can be elicited by having the child extend the knee against resistance or kneel. Lateral radiographs of the knee may be normal or demonstrate swelling, irregularity, or elevation of the tibial tubercle. Treatment consists of NSAIDs, ice, and physical therapy; activity restriction is generally unnecessary. Most cases resolve over 6 to 18 months as the growth plate at the secondary ossification center ossifies.16
Case Conclusion
Initial examination confirmed the presence of a limp; the differential in this age group includes toxic synovitis, septic arthritis, and osteomyelitis. Although Kailey appeared relatively well on examination, her history of recent fever and the worsening symptoms over the past week were concerning. The workup began with plain films of the pelvis and the right knee because of the possibility of referred pain and the lack of localizing signs on examination. In addition, laboratory evaluation was performed, including CBC, CRP, and ESR. Due to her young age, a rapid streptococcal assay, throat culture, or an ASO titer was not necessary.
Plain films of the pelvis and the right knee were normal. The patient’s WBC was unremarkable, but her ESR was 50 mm/hour and CRP was 25 mg/L. Given these elevated inflammatory markers, ultrasound of the right hip was ordered, which revealed a small effusion. An orthopedic specialist was consulted, who performed a sedated joint aspiration. Cell counts from the joint aspirate were sent for evaluation, as well as culture, gram stain, and a PCR for Kingella.
After joint aspiration, Kailey was admitted to the hospital overnight and was started on empiric treatment with IV clindamycin and ceftriaxone. The synovial fluid gram stain was negative, but the WBC was 65,000 cells/mm3. Over the next several days, her inflammatory markers trended downward, she remained afebrile, and her gait slowly improved. The synovial fluid culture remained negative, but the PCR was positive for Kingella. Kailey was discharged on hospital day 3 with a 21-day course of oral cephalexin.
Dr Kane is a fellow in the department of pediatrics, division of pediatric emergency medicine, Vanderbilt Children’s Hospital, Nashville, Tennessee. Dr McMorrow is an assistant professor of emergency medicine and assistant professor of pediatrics, department of pediatrics, division of pediatric emergency medicine, Vanderbilt Children’s Hospital, Nashville, Tennessee.