Retrograde femoral nailing: a focus on the knee

A consecutive series of 23 patients with reamed retrograde femoral nails was reviewed. Nails were placed through the intercondylar notch with a minimal incision. Nineteen patients with retrograde femoral nails were available at an average follow-up of 19.3 months. The union rate was 100% with no infections or malunions. No second surgeries were required for union. Knee range of motion averaged 109 degrees and was greater in those patients with shaft fractures (117 degrees) than in those with supracondylar-intercondylar fractures (91.3 degrees) (P=.02). Pain (0-3 scale) averaged 0.36. Hospital for Special Surgery knee scores averaged 80.4 (90% good or excellent results). Minor knee pain (55%) and secondary surgeries (35%) were common. The only fair or poor results were in patients with preexisting osteoarthritis. A literature review of 14 papers and abstracts was conducted. Exposure, often extensive initially, is more recently percutaneous. The infection rate is acceptable (0-14%), with knee sepsis uncommon. Lower union rates were observed for supracondylar femur fractures (80%-84%) than for femoral shaft fractures (85%-100%) after a single surgery. Second surgeries are common (14%-60%). Varus/valgus malunion, common (12%-29%) with the initial extrarticular entry site, occurs less with the intercondylar entry site. The antegrade femoral nail allows for better control of proximal shaft fractures, while the retrograde femoral nail is more reliable in controlling distal shaft fractures. Rotational malunion still remains a problem. Mild knee pain is common (13%-60%). The treatment of supracondylar femur nonunions with retrograde femoral nailing is disappointing.