Fractures of the distal humeral metaphyseal-diaphyseal junction in children.

BACKGROUND

To our knowledge, there is no report in the English-language literature of metaphyseal-diaphyseal junction fractures of the distal humerus in children. The purpose of this study was to review our experience with this uncommon fracture.

METHODS

Between 1998 and 2004, 422 displaced supracondylar humerus fractures underwent operative reduction and fixation at our institution. A retrospective review of medical records and radiographs revealed that 14 (3.3%) of these fractures occurred at the metaphyseal-diaphyseal junction just proximal to the olecranon fossa. In 8 patients, the fracture line was oblique (group A), and in 6 patients, the fracture line was transverse (group B).

RESULTS

Average age at the time of fracture was 4.9 years (range, 1.5-10 years). All patients were treated by closed reduction and Kirschner wire fixation and had at least 1-year follow-up. In group A, operative time for reduction and fixation was significantly increased in comparison to the 408 remaining supracondylar humerus fractures. However, the clinical course in group A was uncomplicated, and no loss of fixation at follow-up was noted. The operative time in group B was even longer. These fractures were more problematic as loss of fixation occurred in 5 of the 6 patients, 4 occurring in the sagittal plane. In addition, multiple complications arose in group B including reoperation, cubitus varus, pin migration, and prolonged loss of motion.

CONCLUSION

Metaphyseal-diaphyseal junction fractures of the distal humerus in children are rare but can be problematic. The transverse fracture pattern requires additional attention in the operating room with optimal pin fixation. Close postoperative follow-up is necessary. The oblique fracture pattern, while requiring increased time in the operating room for reduction and fixation, is typically stable with the usual fixation used for supracondylar humerus fractures. In summary, metaphyseal-diaphyseal junction fractures of the distal humerus are uncommon elbow fractures in children that should be differentiated from the more common supracondylar humerus fracture for optimal outcomes.

LEVEL OF EVIDENCE

Therapeutic level 4 (case series).