Symptom-Based Diagnosis in Pediatrics (CHOP Morning Report) 1st Ed.

CASE 16-3

Two-Year-Old Boy

JEANINE RONAN

HISTORY OF PRESENT ILLNESS

A 2-year-old boy presented with the chief complaint of refusing to walk. The child was in his usual state of health yesterday and was outside playing with his older brother. While looking outside the mother noted that her son had fallen while running on the grass, but he stood up immediately and continued trying to keep up with his older brothers. Over the remainder of the day he seemed to be acting normally. However, when he woke up this morning there was significant swelling over the right lower leg and he was walking with a limp. There has been no history of fever or viral infections.

MEDICAL HISTORY

The medical history was remarkable. He met all his developmental milestones appropriately.

PHYSICAL EXAMINATION

T 36.9°C; RR 28/min; HR 125 bpm; BP 96/70 mmHg; Height 75th percentile; Weight 50th percentile

In general, the child appeared as a happy, well-developed boy. His physical examination was normal with the exception of the right lower extremity. There was an area of focal swelling and discrete tenderness along the lower third of the tibial shaft. His hip, knee, and ankle examination revealed full range of motion. His neurologic examination was normal; however, he refused to bear weight on his right leg. His skin examination did not demonstrate any bruises or unusual marks.

DIAGNOSTIC STUDIES

Complete blood count revealed 8200 WBCs/mm3

with 54% segmented neutrophils, no band forms 38% lymphocytes, and 8% monocytes. The erythrocyte sedimentation rate and C-reactive protein were normal.

COURSE OF ILLNESS

A radiograph of the right leg revealed the diagnosis (Figure 16-2).

Image

FIGURE 16-2. Radiograph of the tibia.

DISCUSSION CASE 16-3

DIFFERENTIAL DIAGNOSIS

When a child presents with the abrupt onset of refusal to walk, acute injury is the most likely etiology. Determining whether the injury is due to an accident or the result of abuse is a challenging diagnostic issue for physicians. In the case of a toddler’s fracture, a significant traumatic event may not have occurred. It may result from a minor accident involving a fall while walking or running which may have either been dismissed or not witnessed by the parents. Toddler’s fractures typically involve the distal portion of the tibia, resulting in a spiral or oblique fracture. In contrast, when the fracture results from abuse, usually the midshaft of the tibia is involved because of the large amount of force inflicted while holding the foot and twisting the leg. In the case of child abuse, usually the history will not seem plausible with the injury or the developmental age of the child (Table 16-5). If abuse is considered, a skeletal survey should be carried out to evaluate for any other injuries. Fractures involving the metaphysis and epiphysis (bucket handle fractures), the thoracic cage, scapula and spine, as well as complex skull fractures, should raise the suspicion of child abuse (Table 16-6).

TABLE 16-5. Common explanations in the history that raise suspicion for child abuse.

No explanation for a significant injury

Dramatic changes in injury explanation

An explanation that is not plausible, given the injury

Different versions of the incident by caregivers

Mechanism of injury inconsistent with the child’s developmental or physical abilities

TABLE 16-6. Fractures that raise the suspicion for child abuse.

Multiple fractures and no history of major trauma

Fractures at different stages of healing

Rib fractures

Femur fractures in nonambulatory infants

Scapula and vertebral fractures without a history of major trauma

Midshaft humerus fractures

Epiphyseal fractures

Metaphyseal fractures and spiral/oblique fractures in nonambulatory infants

Multiple, complex, or occipital skull fractures

In rare cases, unexplained fractures may be a sign of bone disease. The fracture patterns may be similar in child abuse patients and patients with bone disease. Metabolic bone disease is exceedingly rare and should be considered a diagnosis of exclusion. Osteogenesis imperfecta (OI) is the condition most frequently confused with child abuse. OI is a genetic bone disorder due to a mutation in type I collagen. OI should be considered when these features are present: osteopenia, wormian bones on the skull, blue sclera, abnormal dentition, and a family history of “easy” fractures. However, in some milder forms (OI type IV) none of these features may be seen.

DIAGNOSIS

Radiograph of the right leg demonstrated a spiral fracture involving the tibia (Figure 16-2). The diagnosis is a toddler’s fracture.

INCIDENCE AND EPIDEMIOLOGY

Toddler’s fractures are common injuries seen in children between 9 months and 3 years of age. Developmentally, as children start to master walking, they are prone to fall. They can easily twist their lower leg as the foot is fixed on the ground. A toddler’s rapid increase in linear growth also contributes to the incidence of this problem. It is very unusual to see a toddler’s fracture in the nonambulatory child and this should raise the suspicion of a nonaccidental injury.

CLINICAL PRESENTATION

When a child presents with refusal to walk with isolated swelling of the tibial shaft, one must suspect a toddler’s fracture. In many cases, there may be no definitive history of trauma. In some cases, the incident may have seemed so minor that the parents are unable to recall a fall or injury. The physical examination may be completely normal or there may be minimal swelling, increase in warmth and tenderness. Pain may be elicited by gentle twisting of the extremity.

DIAGNOSTIC APPROACH

Radiographs. Initial evaluation of a toddler refusing to walk and concerns for toddler’s fractures begins with plain films. The antero-posterior and lateral projections will often show a spiral or oblique fraction extending downward and medially in the distal third of the tibia. These findings are often very subtle. In some cases, initial radiographs will be negative or only show minimal soft tissue swelling. If these projections are negative, an internal oblique view may be useful. If your index of suspicion remains high and plain films are normal, a triple phase bone scan can be performed. In other cases, one may immobilize the leg and repeat the radiograph 2-4 weeks later revealing subperiosteal reaction and new bone formation, confirming the diagnosis.

TREATMENT

Treatment primarily involves immobilization via casting if the fracture is discovered within 2 weeks after symptom onset. These patients should be managed in conjunction with orthopedic surgery colleagues.

SUGGESTED READINGS

1. Shravat B, Harrop S, Kane T. Toddler’s fracture. J Accid Emerg Med. 1996;13(1):59-61.

2. Kemp AM, Dunstan F, Harrison S, et al. Patterns of skeletal fractures in child abuse: systematic review. BMJ. 2008;337:859-862.

3. Cooperman DR, Merten DF. Skeletal manifestations of child abuse. In: Reece RM, Ludwig S, eds. Child Abuse Medical Diagnosis and Management. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2001:135-139.

4. Pandya N, Baldwin K, Kamath A, Wenger D, Hosalkar H. Unexplained fractures: child abuse or bone disease. Clini Orthop Relat R. 2011;469(3):805-812.

5. Kellogg N, the Committee on Child Abuse and Neglect. Evaluation of suspected child physical abuse. Pediatrics. 2007;119(6):1232-1241.