Growth recovery lines are more common in infants at high vs. low risk for abuse.

ABSTRACT

BACKGROUND: Growth recovery lines, also known as growth arrest lines, are transverse radiodense metaphyseal bands that develop due to a temporary arrest of endochondral ossification caused by local or systemic insults. OBJECTIVE: To determine if growth recovery lines are more common in infants at high risk versus low risk for abuse. MATERIALS AND METHODS: Reports of American College of Radiology compliant skeletal surveys (1999-2013) were reviewed with clinical records. Infants at low risk for abuse had a skull fracture without significant intracranial injury, history of a fall and clinical determination of low risk (child protection team/social work assessment). Infants at high risk had significant intracranial injury, retinal hemorrhages, other skeletal injuries and clinical determination of high risk. There were 52 low-risk infants (mean 4.7 months, range 0.4-12 months) and 21 high-risk infants (mean 4.2 months, range 0.8-9.1 months). Two blinded radiologists independently evaluated the skeletal survey radiographs of the knees/lower legs for the presence of at least one growth recovery line. RESULTS: When growth recovery lines are scored as probably present or definitely present, their prevalence in the low-risk group was 38% (standard deviation [SD] = 8%; reader 1 = 17/52, reader 2 = 23/52) vs. 71% (SD = 7%; reader 1 = 16/21, reader 2 = 14/21) in the high-risk group (P < 0.001; odds ratio 4.0, 95% CI 1.7-9.5). CONCLUSION: Growth recovery lines are encountered at a significantly higher rate in infants at high risk vs. low risk for abuse. This suggests that abused infants are prone to a temporary disturbance in endochondral ossification as a result of episodic physiological stresses.