Ossification of the Proximal and Middle Phalangeal Condyles: Radiographic Aid in Phalangeal Neck Fracture Reduction.

Abstract

Phalangeal neck fractures are commonly dorsally displaced and angulated. Surgical treatment is often necessary to restore the retrocondylar recess. The purpose of this study was to determine whether radiographic landmarks can serve as a reference tool for assessing phalangeal neck fracture alignment based on age and sex. In total, 1061 lateral finger radiographs that were interpreted as "normal" by pediatric radiologists in children aged 1 to 18 years were retrospectively reviewed. The proximal and middle phalanges of each digit had a line drawn along the volar cortex [termed the volar phalangeal line (VPL)] and a second perpendicular line was drawn at the level of the phalangeal condyle. A ratio of the anterior to posterior aspects of the phalangeal condyle was determined at the intersection of these lines. Sex of the patients was noted to determine whether it influenced the temporal course of ossification. A linear regression model was utilized to determine the annual coefficient of growth for the phalangeal condyles. There is a temporal course of ossification of the proximal and middle phalangeal condyles. As children increase in age, the VPL will intersect the phalangeal condyle more dorsally due to the eccentric ossification. In children above 9 years of age, the VPL will reliably intersect the middle one third of the phalangeal condyle. No clinically significant difference exists between the ratios of the proximal and middle phalanges. Sex was not associated with a difference in growth. The greatest growth increase was observed in the 8 to 9-year-old interval. The phalangeal condyles ossify in an eccentric manner and the VPL will intersect the phalangeal condyle more dorsally with increasing age. The VPL and knowledge of where it should intersect the phalangeal condyle can be used as a reference guide for evaluating the reduction of proximal and middle phalangeal neck fractures in children. Level III.