Solving the Mystery of the Limping Child
From injury to infection, there are a myriad of reasons why a child can present with an acute limp. Overuse is the most common cause; septic hip, septic knee and tumors are among the most concerning. The potential ramifications of a delayed or improper diagnosis underscore the importance of thorough investigation.
“If it’s something that could potentially cause harm like a septic joint or osteomyelitis, the sooner we can intervene, the more we decrease our chances of a bad outcome,” says Maegen Wallace, MD, ATC, with Children’s Hospital & Medical Center in Omaha. “In cases of septic hip, for example, negative outcomes can range from cartilage destruction to avascular necrosis,”
A limp is defined as a deviation in the walking pattern away from the expected normal pattern for the child’s age. The most prevalent causes of limping in children are wide-ranging, and include overuse, fracture, tarsal coalition and infection.
The journey toward an accurate diagnosis–and the most effective treatment–begins by obtaining a thorough patient history. Dr. Wallace also recommends incorporating a number of key components into the comprehensive physical exam, including observation, taking of temperature and vital signs, a gait exam, a table top exam to determine the affected joint, and a standing/floor exam.
Dr. Wallace says imaging–starting with two views of the affected joint–is warranted any time an acute limp is involved. X-rays are normally used to evaluate for septic joint, osteomyelitis or tumors. An MRI or bone scan can be helpful if the child is sick. In those cases, lab tests, including CBC, ESR and CRP, are also needed to evaluate for infectious processes. If the child is febrile, blood cultures at the time of fever are recommended as well.
Dr. Wallace recommends urgent referral for patients who have acute limps with fever and suspected septic joint or osteomyelitis. The pre-adolescent or adolescent with a slipped capital femoral epiphysis also needs to be made non-weight bearing and transferred urgently. Other types of limps can be referred on a less urgent basis.
The most effective treatment for the limping child is driven by the cause of the limp. For optimal outcomes, Dr. Wallace says limping children should be seen by an orthopaedic surgeon who specializes in pediatric patients.