Pediatrics · Year 3 · from Pediatrics
Case 3: Physical Abuse with Sentinel Injuries
Patient Demographics
- Age: 5-month-old male
- Sex: Male
Chief Complaint
"His leg seems swollen."
History of Present Illness
A 5-month-old infant is brought to the pediatric clinic by his mother who noticed swelling of his right thigh this morning. She reports he has been fussier than usual for the past 2 days but has no fever, vomiting, or change in appetite. When asked about possible injury, she says she "doesn't know" what happened but wonders if his 3-year-old sister may have stepped on him. The infant was seen in this clinic 3 weeks ago for a "bruise on his ear" that the parents attributed to the baby hitting himself with a toy. He is not yet rolling over independently.
Physical Examination
- Vital Signs: Temperature 37.0C, HR 128 bpm, RR 28/min
- General: Fussy infant, cries with movement of right leg
- HEENT: Small fading bruise (0.5 cm) on right ear pinna
- Right thigh: Swelling of mid-thigh, tender to palpation, decreased spontaneous movement
- Left leg: Normal
- Skin:
- Fading yellow-green bruise on right ear pinna
- Two small (0.5 cm) round bruises on left upper arm
- Small bruise on right cheek
- Abdomen: Soft, non-tender
- Neurologic: Moves left arm and leg normally; guards right leg
Imaging Findings
- Right femur radiograph: Acute spiral fracture of the mid-diaphysis
- Skeletal survey: In addition to right femur fracture: healing left clavicle fracture (approximately 3-4 weeks old); healing right 7th rib fracture posteriorly (approximately 2-3 weeks old)
Diagnosis
Non-accidental trauma (physical child abuse) with multiple fractures and sentinel injuries
Clinical Reasoning
This case demonstrates several critical findings of physical abuse:
Sentinel injuries (minor injuries that precede more serious abuse):
- Ear bruise at prior visit - bruising to the ear in a non-mobile infant is highly concerning; the ear is a protected location (TEN-4: Torso, Ear, Neck in children under 4)
- Multiple bruises in a 5-month-old who is not yet rolling: "Those who don't cruise rarely bruise"
Current findings:
- Spiral femur fracture in a non-ambulatory infant - requires significant rotational force inconsistent with a sibling stepping on the leg
- Unexplained mechanism with changing story
- Multiple fractures at different stages of healing indicating repeated trauma over weeks
The prior "ear bruise" was a sentinel injury that, had it been recognized as concerning at the time, might have prompted earlier intervention and prevented subsequent injuries.
Management
- Report to Child Protective Services: Mandatory; immediate report required
- Full skeletal survey: Completed; demonstrates pattern of repeated abuse
- Follow-up skeletal survey: Schedule for 2 weeks to identify additional healing fractures
- Orthopedic consultation: For femur fracture management
- Complete laboratory evaluation: Coagulation studies, calcium, phosphorus, alkaline phosphatase to exclude metabolic bone disease
- Head CT and ophthalmologic examination: Even without neurologic symptoms given pattern of abuse
- Detailed documentation: Complete, objective record with photographs
- Safety planning: Child requires protective custody; cannot be discharged to home
- Sibling evaluation: 3-year-old sister requires medical and safety evaluation
Clinical Image
Image Description: Radiograph demonstrating a classic metaphyseal lesion (corner fracture), a fracture pattern highly specific for non-accidental trauma resulting from shearing forces across the growth plate.
Source: Radiopaedia URL: https://radiopaedia.org/cases/classic-metaphyseal-lesion License: CC BY-NC-SA 3.0