Growth recovery lines in infants, toddlers may indicate abuse

Radiologists should report the presence of 10 or more growth recovery lines seen on X-rays of  the arms and legs of children under 2 years of age, say pediatric radiologists from the Children’s Hospital of San Antonio, who suggest in the Sept. 14, 2019, online edition of Pediatric Radiology that such lines may be a sign of neglect, or worse.¹

Growth recovery lines are radiodense metaphyseal bands that develop from a temporary arrest of endochondral ossification. They occur in large bones traversing parallel to the physis involving at least 50% of the width of the physis. They may be indicators of stress and can occur following periods of normal temporary growth cessation. In addition to being associated with fractures involving the epiphysis, childhood illnesses, and birth via vaginal delivery, they are also associated with malnutrition and maltreatment.

Along with child abuse specialists at the UT Health Sciences Center at San Antonio, the radiologists retrospectively studied the significance of growth recovery lines identified in children 24 months and younger who were abused and/or neglected. The cohort consisted of 135 children who had a skeletal survey performed within an eight-month period, 51 of whom were considered at risk for physical abuse and 26 at risk for neglect. Fifty-eight children, representing a “low risk” group, sustained injuries or conditions that were accidental or explained by natural causes.

Two pediatric radiologists blinded to clinical records independently reviewed each skeletal survey. They recorded the number of growth recovery lines on distal and proximal sites of each long bone, fractures of any bone, and the absence or presence of osteopenia.

The mean number of growth recovery lines was 3.2 for the low-risk group, 7.3 for the neglected group, and 7.6 for the abused group, according to lead author Lora R. Spiller, MD, assistant professor of pediatrics in UT Health’s Division of Child Abuse Pediatrics. They reported that the three bone sites with the most growth recovery lines, in decreasing order, were the distal radius, the proximal tibia, and the distal tibia. More were identified in the proximal tibia than the distal tibia in the neglected and low-risk groups.

Four prior fractures were visible in children who were neglected and abused, compared to two in the low-risk group. Osteopenia seen in skeletal surveys was also significantly greater: 23% compared to 1% in the low-risk group.

The San Antonio study expands upon the findings of a 2016 Boston Children’s Hospital study that had also determined that growth recovery lines were nearly twice as prevalent in infants under 1 year of age at high risk (71%) compared to low risk (38%).²

But because the authors observed that children in the maltreated group were more likely to develop growth recovery lines at a younger age compared to the low-risk group, the authors suggest “that growth recovery lines might be better at distinguishing abused and neglected children from low risk-children younger than 15 months.” They noted that within this age group, specificity for maltreatment was more than 84% when at least 10 growth recovery lines in the long-bones of the extremities.

“The results of our study suggest that by considering maltreatment when several growth recovery lines are identified, we could decrease the frequency of missed cases of abuse and neglect,” the authors wrote.

REFERENCES

1. Spiller LR, Kellogg ND, Mercado-Dean M-G, et al. Growth recovery lines: a specific indicator of child abuse and neglect? Pediatr Radiol. Published online September 14, 2019. doi: 10.1007/s00247-019-04526-x.
2. Zapala MA, Tsai A, Kleinman PK. Growth recovery lines are more common in infants at high vs. low risk for abuse. Pediatr Radiol. 46:1275-1281.