Pediatric Primary Care Case Studies (127 page)

   All upper extremity joints have full range of motion with no swelling, erythema, or pain with palpation.

   His right ankle, knee, and hip have unrestricted pain-free motion.

   His left hip is held flexed, abducted, and externally rotated.

   He has guarding and begins to cry and pushes your hand away when you attempt to move the left hip.

   His left knee and ankle are nontender and have no swelling or erythema.

   His leg and thigh measurements are circumferentially equal.

   His leg lengths are equal.

The examiner must also take into account the normal gait of young children. Characteristics of childhood gaits are found in
Table 32-1
. Because Tyler will not walk, you cannot assess his gait today.

Differential Diagnosis

A limp is defined as any deviation from a normal gait pattern for the child’s age. An antalgic limp is caused by pain and is remarkable because the amount of time the patient spends with his or her body supported by the involved extremity is reduced. In contrast, a short leg limp caused by a leg length difference results in a gait in which equal time is spent on both legs. A chronic limp of weeks to months is typically associated with atrophy of the thigh and calf as well. The inability of young children to clearly describe the location and nature of their pain contributes to the diagnostic challenge.

Common causes for antalgic limp are conditions that cause hip pain such as trauma or inflammation. Inflammation, in turn, can be caused by infection, arthritis, neoplasia, and vasculitis. The causes of limp in the pediatric population can be further sorted by age.

For a 4-year-old, the most relevant considerations are:

•   Trauma

•   Infection

   Bacterial infection of the hip joint

   Osteomyelitis of the femur or acetabulum

   Postviral synovitis (toxic synovitis)

•   Developmental

   Congenital hip dysplasia (CHD)