Evaluation of a limping child is challenging for clinicians because of the multitude of potential diagnoses. Parents and caregivers often describe their child is ‘limping’ when they notice an abnormal gait.
Thus, it is important for clinicians to differentiate between normal gait and abnormal gait for age. For this it is important they understand normal gait patterns. Gait accompanied by history and physical examination, can guide clinicians in coming to a differential diagnosis to advice further investigations.
Normal gait is a smooth, rhythmic process that requires minimal expenditure of energy. When children begin ambulating, which occurs most typically between the ages of 12 and 16 months, they show what is commonly referred to as toddler pattern. This pattern is characterized by short stride lengths and wide base gait leading to frequent falls. The fluidity of gait improves between 3 and 5 years of age when the arm and leg reciprocity is attained, and the overall coordination is improved. By the age of 7 years, the child shows a mature adult gait.
A limp is a deviation from a normal age-appropriate gait pattern resulting in an uneven, jerky, or laborious gait, and can be caused by pain, weakness, or deformity as a result of a variety of conditions. The exact incidence of limping in children is unknown.
An antalgic or painful gait is one resulting from pain in the heel, knee, or hip. If it is painful enough, the child may refuse to weight bear altogether. Non-antalgic (or nonpainful gait) can also be sign of underlying bony or neurologic issues.
Equinus or toe-walking gait can be habitual or idiopathic or can be caused by tight heel cord in clubfoot or cerebral palsy. In Trendelenburg gait pattern, children have the appearance of shifting their weight over the affected side. This pattern can be seen in Perthes disease, developmental dysplasia of the hip (DDH), muscular dystrophy, and hemiplegic cerebral palsy.
History Depending on the age of the child, getting an accurate history can be difficult, and thus being able to interview the parents or primary caregiver is important. Ask about family history of autoimmune diseases, neuromuscular diseases infection exposure, and recent travel.
Examination In general, look at the appearance of the patient. Does the patient look lethargic, irritable, or ill? Is the child comfortable walking? Be sure to expose the child completely without shoes. First it is very important to observe the child’s gait from all sides. Then child is then examined from head to toe in standing and supine positions.
Local examination of the painful part is very important and can let us know whether we are dealing with an acute painful cause like trauma or an infection or a subtle relatively painless issue like Perthes disease of the hip. Associated features like limb length discrepancy, limb deformity and restricted movements should be checked for.
Diagnostic TestsLaboratory tests are most commonly indicated when the history and physical examination are consistent with possible infections or inflammatory causes. These tests include a complete blood count, erythrocyte sedimentation rate (ESR), CRP (C-reactive protein) and blood cultures.
Imaging The imaging of limping children is based on the patient’s age, location of pain, history and mode of trauma and concern for infection. Plain radiographs should be done first, before any advanced imaging. In most situations, anteroposterior (AP) and lateral radiographs of the segment are most helpful. Some fractures and early infections have negative radiographs initially. If infection is a possible diagnosis, then laboratory tests and imaging like ultrasonography or MRI have high sensitivity for detection of bone and joint infections.
Causes Consideration of some of the common and worrisome diagnoses can help clinicians become aware of the things they should be thinking about and should not miss.
Traumatic injuries - Emergent paediatric orthopedic consultation is required in significant trauma.
Toddler’s fracture – Undisplaced fracture of the distal tibia which usually has an excellent prognosis.
Nonaccidental trauma – It should be immediately suspected in a non-ambulatory child with lower-extremity fractures or a child with fractures at different stages of healing.
Septic arthritis , commonly of the hip and osteomyelitis of the proximal femur are common causes of severe limp and need to be investigated.
Transient synovitis of the hip: Another common cause, which is self-limiting.
Mono-articular Juvenile Rheumatoid arthritis affecting the hip or the knee.
Developmental Dysplasia of the Hip (DDH), Legg-Calve´ -Perthes Disease (LCPD), and Slipped Capital Femoral Epiphysis (SCFE) are the 3 most common hip conditions in children and adolescents that present with atraumatic limping.
Tumors and malignancies Benign neoplasms and malignancies are uncommon causes of limping but can be the most common reason for anxiety in parents. Any child with limping with vague limb pain which is not relieved by oral medications, needs to be evaluated for malignancies especially hematological malignancies like Leukemia and Lymphoma.
Spine Spinal disorders can manifest as lower-extremity issues and should be considered. Some examples are diskitis, epidural abscess, herniated discs, psoas abscess and spine tumors.
SUMMARY Limping presents a diagnostic challenge because of the number of possible causes. A careful and systematic evaluation can shorten the long list of potential diagnoses to direct appropriate diagnostic tests to determine the cause of the problem. Transient synovitis, trauma and infections are the most common causes of painful limp. Inflammatory conditions, developmental diagnoses, and overuse injuries are other causes. Although rare, malignancies, such as osteosarcoma and blood cell cancers, must also be considered as potential causes of limping in children and adolescents.