David R Godley

 A practical approach to the child who limps 

 Limping takes many forms, and the cause is not always obvious. The keys to diagnosis are careful observation of the gait disturbance and systematic evaluation, especially high-quality radiographs.

 Limpinga disturbance of normal locomotionappears in many variations

: A limp can be subtle or pronounced, chronic or acute, and is not always easy to describe or understand.

 Some causes of limping, such as a fractured foot, are obvious; other causescerebral palsy (CP) or other associated movement disorders, for exampleare less clear. Diagnosing a limp in a child can therefore be difficult, and misdiagnosis of a serious condition, such as developmental dysplasia of the hip, can cause trouble for everyone. In addition to difficult clinical challenges and liability issues, we all have to live with new paradigms of cost-containment and patient satisfaction. We are therefore uncomfortable at the thought of diagnosing a limp.

 After reviewing this article the physician should be able to: 

 This article outlines a practical approach to evaluating the limping child, including case histories with examples of gait analyses. Systematic assessment will help you to accurately analyze and describe causes and mechanical categories of limping and arrive at a proper diagnosis and suitable treatment recommendations, thereby satisfying patients, parents, and consultants, as well as yourself.

Five types of mechanical impairment of gait have been described by others: deformity-related gait, antalgic (painful) gait, stiff-joint gait, gait affected by neuromuscular weakness, and gait affected by unequal limb length.

Limb deformity (knock- knee, bowleg) is the most obvious cause of limping.

 Deformities extensive enough to affect postural alignment and locomotion are clear to every clinician and therefore are not discussed here.

 A child with antalgic limpas from a lacerated soleshortens the stance (with the foot on the ground) phase of the gait cycle on the affected side

 and hurries to unload his (or her) weight from the sore part. Joint stiffness also produces a readily apparent dysfunction,

 an example of which is the "peg leg" limp seen in a child with a fused knee. Leg-length inequality produces a teeter-tottering trunk sway as the child vaults on the long leg and steps down on the short one.

 A child with hemihypertrophy, which causes one leg to be noticeably longer than the other, is an example of this type of impairment.

Weakness from neuromuscular diseasesuch as polio, CP, spina bifida, or muscular dystrophy

 can produce complex mixtures of gait abnormalities such as toe walking, Trendelenberg lurch, hyperlordosis, and crouch.

 Describing them can challenge even the best experts in the gait laboratory.

 Fortunately, most weakness-related limping is both chronic and obvious; you may elect to refer a child with this type of gait impairment to a pediatric orthopedic surgeon.

 A common challenge for pediatricians is to evaluate a newly developed (or, at least, newly observed) limp in a previously healthy child. Describing the new-onset limp mechanically helps you deduce its cause.

 The technique I recommend for evaluating a limping child is to observe the undressed child walking in a long private hallway (Figure 1, available in the print edition, adapted from Staheli LT: Torsional deformity 

Encourage the child to walk as normally as possible back and forth several times while focusing your attention on one particular element of gait at a time.

 Unhurried observation is the key to successful gait analysis, but note: A child's inability or unwillingness to walk is also significant. I have seen several children who had septic joints and a history of limping but who completely refused to walk because of pain after they had been brought into the office. (For another case of a child who refuses to walk, see the 

 Beginning at the foot, watch for range of motion, postural alignment, weight acceptance, cadence, coordination, and general fluidity of movement.

 Note how each element differs from the normal pattern, which usually can be seen in the opposite limb, and describe it. (For example, you might record in your notes "toe walks," "walks only on lateral border of foot," or "drags toes.") Observe each part of the limb (foot, knee, hip, trunk-spine) in similar fashion. Remember to examine the spine; problems such as diskitis, tumors, and fractures can manifest themselves as a gait abnormality.

 When you have assembled a complete description of the child's gait disturbance, note the essential qualities of the gait and compare them with patterns that you recognize (Trendelenberg abductor lurch, antalgic limp, or short-leg limp, for example). Your gait analysis need not contain technical data or scientific jargon.

 Clarity is the goal: Simple, clear description of abnormalities in ordinary language (tiptoe, flatfoot, swayback, stiff knee) is preferable. Let the facts speak for themselves and do not worry too much about terminology. That being said, familiarity with common musculoskeletal terminology is still useful as a means to describe gait abnormalities, so a brief 

Identifying the cause of the limp (fractured tibia, septic hip, slipped capital femoral epiphysis) is the ultimate goal of your evaluation. Remember, limping is a sign of disease; it is not the diagnosis.

 By thoroughly describing a limp, we can identify a specific physiologic abnormalitysuch as stiff knee or short legbut not necessarily its causeinfection or fracture, for example. Diagnosis depends, therefore, on pulling together information from the history, gait analysis and other physical findings (limited range of movement, swelling), radiographs, and laboratory dataspecifically, a complete blood count (CBC) and erythrocyte sedimentation rate (ESR).

Although a thorough medical history and physical examination, including careful gait analysis, are your best diagnostic tools, you may occasionally need to confirm the diagnosis with more extensive testingsuch as magnetic resonance imaging (MRI) or joint aspiration. Usually, however, the medical history and physical examination, plain films, CBC, and ESR will get you most of the way toward a definitive differential diagnosis in one of the following categories of gait disturbance: infectious, developmental, inflammatory, neuromuscular, traumatic, or neoplastic.

 To help you establish the differential diagnosis, the table lists common causes of limping in children. This table is derived from an excellent review by Richards,

who reminds us that the causes vary for different age groups. Categorizing the patient as toddler (1 to 3 years of age), child (4 to 10 years), or adolescent (11 to 15 years) can help you to recall possible diagnoses characteristic for certain ages, even though considerable overlap exists in these age-based categories: 9-year-olds do occasionally have a slipped capital femoral epiphysis, for example, and a teenager can have a septic hip. In addition, keeping in mind broad diagnostic categories such as infectious and traumatic reminds you to order appropriate studiesESR for suspected pyoarthrosis and biplanar radiographs for suspected slipped capital femoral epiphysis.

Plain films remain the reference standard for orthopedic diagnosis.

 To avoid missing something, always insist on excellent orthogonal films of the entire bone of interest. It is easy to become too focused on an apparent source of trouble and accept what seem to be adequate filmsonly to discover later that the films (and you) missed the most diagnostically relevant part. Too often, for example, ankle films are read as normal when a tumor or fracture is actually located slightly more proximal than the films are capable of revealing.

To avoid such misses, always demand that films of a long bone clearly show anteroposterior and lateral views of the entire shaft and the joints at both ends. Films that fail to do this are analogous to a chest film that shows only one lung. Children's bones have many confusing growth plates and epiphyses, of course, so a tactic I often use to avoid error is to obtain comparison views of the opposite (healthy) extremity. Again, I emphasize: Even with the widespread availability of bone scans and magnetic resonance imaging, high-quality plain radiographs remain the essential imaging tool when evaluating a limping child.

The following five cases provide examples of the diagnostic evaluation of children with varying causes of limping.

Case 1: A 13-year-old boy limping for six months.

 The boy began to complain in June of pain in the knee after soccer practice; he did not arrive for treatment until November. There was no history of a specific injury. The pain was vague and dull and did not prevent the boy from playing. His parents brought him to the office for evaluation after a school holiday because he was limping.

Physical examination showed that the patient lay with the affected leg externally rotated and somewhat flexed at the hip. The flexion- extension arc appeared normal, but the boy could not flex the hip without externally rotating the limb. He could not rotate the limb internally at all. No bruising or tenderness was evident, and the leg appeared normal.

 Gait analysis showed an antalgic limp on the affected side with external rotation of the whole limb, shortening of the stance phase, and mild trunk sway (lurch due to abductor inhibition).

 Radiographs of the hip showed curvature of the femoral neck, widening and irregularity of the capital femoral physis, and 30% slippage of the epiphysis off the posterior femoral metaphysis (Figure 2). The final diagnosis was slipped capital femoral epiphysis of the stable (chronic) type.

Case 2: An 8-year-old girl limping for three days. 

The girl had been playing in a duck pond 10 days earlier when she hurt her foot. She thought she had stepped on something, but her mother saw no bleeding or wound. When the child was seen in the office, she had been limping for three days but was not complaining much and had not been ill.

The physical examination was normal except for a 1.5-mm puncture wound beneath the fifth metatarsal head and a trace of cellulitis surrounding the wound.

 Gait analysis showed antalgic gait on the affected side, shortening of the stance phase, and a marked tendency to bear weight only on the heel. Radiographs showed diffuse osteolysis of the fifth metatarsal head and a few tiny flecks of metallic foreign material overlying the bone (Figure 3). The diagnosis was 

Case 3: A 22-month-old boy limping for one week.

 The child had been playing with his cousins at a playground on Sunday afternoon, but none of them was aware of an injury having occurred. He fell asleep in the car on the way home, so his mother put him to bed. On Monday morning, the boy avoided standing on his right foot for the first few minutes after his mother got him up. Gradually, he began to walk on the foot, but not normally. His mother could see no bruise or swelling, and the child was not crying, so she decided to "wait and see." In a few hours, the child started walking better, so she continued to observe him.

Each day, the pattern was repeated: The boy would not walk at first, then gradually improved to almost normal by afternoon. Because he continued to walk tentatively, his mother brought him for a checkup a week after his afternoon on the playground.

Physical examination showed an apprehensive child who did not want to cooperate and preferred to stay in his mother's lap. He had no sign of injuryno bruise, swelling, or deformityand no restricted motion of hip, knee, or ankle of either leg. He did seem a bit more fussy when the distal part of his right leg was touched, however.

Gait analysis showed toddler's gait with a slightly shortened stance phase on the right foot. Examination was difficult because the child would take only a few steps while reaching up for his mother.

 Radiographs showed a faint, spiral, longitudinal, hairline, radiolucent crack in the distal part of the right tibial metaphysis, 3 cm proximal to the physis (Figure 4). The final diagnosis was toddler's fracture of the distal part of the tibial shaft. We find that children can tolerate some use of the affected limb despite this type of fracture because the fracture is so stable; symptoms are thus intermittent.

Case 4: A 7-year-old boy limping for four months.

 This boy had always been very active in sports, but his parents could not recall his having sustained any particular injury. They brought him to the office for a checkup because the soccer coach thought the child was limping. He had not been sick.

Physical examination showed a thin, wiry, energetic boy who appeared healthy and fit. He had no pain or deformity but showed somewhat restricted left hip motion. Rotation and abduction of the left hip were each 50% reduced. The left leg did not appear shorter than the right.

Gait analysis showed graceful swaying of the trunk on the affected side, slight shortening of the stance phase, and dipping or lurching of the trunk toward the left.

 Plain films showed gross flattening of the left capital femoral epiphysis, with sclerosis typical of avascular necrosis (Figure 5). The final diagnosis was whole-head type Legg-Calvé- Perthes disease.

Case 5: An 11-year-old boy walks "funny." 

The boy's father brought him in for examination because he had been "walking funny" for several years. He had no history of physical trauma or clinically significant illness. Gait analysis revealed a grossly obvious limp manifested by vaulting over the left leg and stepping down (as into a hole) on the right leg.

Physical examination showed an apparently healthy child who was limping. Scoliosis was apparent when the child was standing, and tape measurement showed his right leg to be 3 cm shorter than the left.

 Results of a neurologic examination were normal, and all joints showed full range of motion. The left leg felt slightly warmer to the touch than the right leg, but the skin appeared normal.

 Radiographs showed normal-appearing physes and bony architecture, but scanograms confirmed 3-cm shortening of the right leg: Half the shortening was in the femur; half, in the tibia (Figure 6). The final diagnosis was hemihypertrophy of the left leg as a result of deep-seated arteriovenous fistulae.

1.	Andriacchi TP, Hurwitz DE: Biomechanics of gait, in Beaty JH (ed): 

. Rosemont, Ill., American Academy of Orthopaedic Surgeons, 1999, pp 47-55 

 	2.	Phillips WA: The child with a limp. 

 	3.	Tylkowski CM: Assessment of gait in children and adolescents, in Morrissy RT (ed): 

Lovell and Winter's Pediatric Orthopaedics

, ed 3. Grand Rapids, Lippincott, 1990, pp 57­90 

, ed 14. Baltimore, Williams and Wilkins, 1958 

 	5.	Choban S, Killian JT: Evaluation of acute gait abnormalities in preschool children. 

Bedside Diagnostic Examination: A Comprehensive Pocket Textbook

 	7.	MacEwen GD, Dehne R: The limping child. 

 	8.	Prior JA, Silberstein JS: Nervous system, in Prior JA, Silberstein JS (eds): 

, ed 2. St. Louis, Mosby, 1963, pp 334­339 

 	9.	Richards BS: The limping child, in Richards BS (ed): 

. Rosemont, Ill., American Academy of Orthopaedic Surgeons, 1996, pp 3­9 

, ed 29. Philadelphia, WB Saunders, 2000 

THE AUTHOR is chief of orthopedics at Kaiser Permanente's San Jose Medical Center, where he practices pediatric orthopedic surgery. Presented in part at: Wibbelsman C, moderator: Pediatric grand rounds: Orthopedics, April 9, 1999 (videotape). Oakland, Calif., Kaiser Permanente, Multimedia Communications, 1999. 

 Joint immobility and consolidation caused by disease, injury, or surgical procedure 

 Painful; posture or gait adopted to avoid pain 

 Lacking impetus, without push-off, lacking spring or energy 

Articles

Limping takes many forms, and the cause is not always obvious. The keys to diagnosis are careful observation of the gait disturbance and systematic evaluation, especially high-quality radiographs.

David R Godley

Articles

CME: A practical approach to the child who limps