Supracondylar fractures are common in children. Fractures of the distal humeral metaphyseal- diaphyseal junction in children are far less common. The goal of this study was to report experience with these uncommon fractures over a six year period.
Between 1998 and 2004, 422 displaced supracondylar humeral fractures underwent operative reduction fixation. Of this group, 14 fractures occurred at the metaphyseal-diaphyseal junction. There were two subtypes; an oblique fracture with a lateral spike had occurred in 8 patients, and a transverse fracture that occurred in 6 patients. All fractures were displaced into extension. Medical records were reviewed as well as patient demographics, operative findings, and radiographic outcome.
The average age of these patients was 5 years. The majority involved a fall primary on the playground. All patients were treated by closed reduction with Kirschner wire fixation within 24 hours of injury. A variety of pin fixations were utilized including cross pins, lateral entry pins, medial pins, etc. There were a variety of reduction and postoperative problems. In the oblique pattern, the lateral humeral capitellar angle averaged 28 degrees after surgery. In transverse group, the lateral humeral capitellar angle averaged 39 degrees and subsequent lost of fixation occurred in 5 of 6 patients. Average operative time was fairly long, averaging 53 minutes. Fortunately, remodeling gradual improved the malunited fractures.
The authors indicate that this metaphyseal-diaphyseal fracture pattern is more difficult to treat than your standard supracondylar fracture. There are two subsets of this variant; an oblique fracture pattern and transverse fracture pattern. Transverse fractures are particularly difficult in which to obtain reduction. Subsequent loss of reduction is common and needs to be motored closely. Pin fixation is always difficult in transverse fractures, and this may explain the author’s difficulty in maintaining fixation. If this fracture pattern is encountered, the physician should expect difficulty with reduction and fixation. Furthermore, meticulous postoperative motoring is necessary to detect any loss of position.