Transverse Fracture of the Distal Femoral Metadiaphysis A Plausible Accidental Mechanism

Objectives: This study describes the mechanism of injury of an impacted transverse fracture of the distal femoral metadiaphysis. Individual experience by child abuse pediatricians with this fracture type has suggested that it is less associated with inflicted trauma than was described in a prior case series. Methods: Case contributions were solicited from an international group of child abuse clinicians. Eighteen cases were accepted for analysis. Cases were categorized as abuse or nonabuse by a predefined categorization scheme. Differences in the 2 groups were analyzed by Fischer exact test. Results: Thirteen cases (72%) were determined to be nonabusive, and 5 (28%) were determined to be from abuse. Additional skeletal injuries on skeletal radiograph survey, absence of any explanatory history, and significant changes in repeated histories identified cases of abuse. A short fall was accepted as the explanation for the nonabuse cases, with some indication that direct impact on the knee explained the injury. Conclusions: impacted transverse fracture of the distal femoral metadiaphysis may occur as a result of an accidental short fall of young children. A traditional abuse evaluation should be pursued in these cases, but with an absence of additional skeletal findings, and a history of a fall, it is likely that an accidental mechanism accounts for the injury.