Displaced distal femur metaphyseal fractures: clinical and radiographic outcome in children aged 6-16 years treated by elastic stable intramedullary nailing.

Fractures of the distal femur metaphysis (DFM) are rare. The main objective of this study was to retrospectively evaluate the clinical and radiographic outcomes of displaced DFM fractures in children treated by elastic stable intramedullary nailing (ESIN). We retrospectively reviewed 24 DFM fractures, including five pathological fractures secondary to non-ossifying fibroma (mean age, 10.9 years; range, 6-16) who underwent surgical treatment by ESIN. The patients were followed radiographically and clinically on a regular basis. Sixteen boys and eight girls were included in the study. Radiographically, all fractures healed, but five healed with complications. Most of the DFM fractures were transverse (n = 18, 75%), and all patients but two (91.7%) underwent closed reduction and stabilization of the fracture. All the patients were pain-free at their last follow-up. All regained full normal activities, although five patients developed a postoperative complication (20.8%). At the last follow-up visit, all fractures achieved union including the two cases of nonunion; moreover, none of the patients showed any signs of growth arrest or disturbances in radiological and clinical assessment. On the ESIN outcome measure scale, 12/24 patients (50%) had excellent results, 11/24 (45.8%) had good-satisfactory results and 1/24 (4.2%) had poor results. Fracture of the DFM can be challenging due to the relatively short length of the distal fragment, the proximity of the growth plate and the tendency of the distal fragment to displace. Following the surgical principles and understanding the anatomical constraints of the distal femur help to obtain satisfactory clinical and radiological results.