Paediatrics: The limping child

The limping child

Exclude trauma and infection before considering other disorders.

Examination

Lower limbs, back, and abdomen need to be examined. Observe the fol-lowing:

•   Limb position of least pain (e.g. in hip septic arthritis, the hip is held in flexion and external rotation).

·  Gait

•   Movement and mobility:

•   ability to weight bear passively and actively;

•   ability to move the joints and limbs freely;

•   palpate for tenderness, heat, and swelling around the joint; palpate the entire length of the extremity, the abdomen, and spine;

•   leg length difference: anterior superior iliac spine (ASIS) to medial malleoli. to determine if discrepancy is in femur, or tibia perform galeazzi test (flex knees and hips and examine from the side);

•   range of movement (ROM): in individual joint and compare with other side;

•   neurological and vascular status: abdominal examination.

Beware of referred pain from joint above or from the abdomen (con-sider appendicitis, inguinal hernia, UTI with hip pain). Always assess the joint above and below. Hip pathology may present as knee pain.

Investigations

·  Temperature.

•   Bloods: FBC, ESR (may be normal), CRP, blood cultures, blood film, rheumatoid factor (RF), antinuclear antibody (ANA), anti-streptolysin (ASO) titre, Lyme titre, HLA-B27.

•   Urine: dipstick + MSU.

•   X-rays: antero-posterior (AP), lateral plain X-ray of entire bone involved including joint above and below (e.g. if hip: AP pelvis and frog leg lateral views).

•   US scan: of muscle and bone.

•   MRI: very sensitive and specific—good for soft tissues and bone pathology.

Three phase bone scan: when pain not easily localizable; sensitive, but not specific. Radiation exposure.