Outcome of Distal Femoral Nonunions

Background: Distal femoral fractures account for about 5% of all femoral fractures, historically considered to have 95% healing rates after operative treatment. Despite the advent of distal femoral locking plates (DFLP) , higher than expected nonunion rates were recently reported. The aim of this study was to investigate the distal femoral nonunion (DFNU) rates and their outcome.

Patients and Methods: Design: retrospective cohort study in an Academic, level I trauma center. ICD9-CM codes were used for patient retrieval from the hosptial`s medical records. Demographic details including age, sex, mechanism of injury, and comorbidities. Operative data (including implant type and surgical technique) was documented. Latest follow up outpatient clinic and radiographs were used to assess outcome and complications.

Results: 13/72 (18.3%) patients DFNU were identified. Seven were male patients. Mean age was 48.8 (25-83). Mechanism of injury was fall, and motor vehicle accidents. Initial treatment was staged protocol (External fixation converted to DFLP) in 5 patients, primary DFLP in seven patients, and retrograde nailing in one patient. Average time from initial surgery to first intervention was 6.86 month. Revision surgery included re-plating with DFLP in most patients but one. Bone grafting (Autologous iliac crest or DBM) was applied 5 cases. Double plating was performed in 2 patients. Three patients were infected proven by intraoperative biopsies form the revision surgery. 6/13 patients did not heal after the secondary procedures and required further intervention. One went segmental resection and bone transport over plate, One case was converted to a retrograde nail, two went repeat plating and one patient required ICBG. Two patients failed to heal. Mean time to union after final procedure was 10.5 months

Conclusions: DFNU is more common than previously described. It is a challenge for the trauma surgeon and requires repeat procedures with a significant failure rate.