Comparision of the expandable nail with locked nail in the treatment of closed diaphyseal fractures of femur
Background: Expandable nails achieve stability only by hydraulic expansion; therefore suggest less radiation exposure and operation time. In this study, we aimed to compare the results of expandable femoral nails with locked intramedullary nails in the treatment of diaphyseal fractures of femur.
Materials and Methods: Isolated closed AO = Arbeitsgemeinschaft für Osteosynthesefragen type 32.A or 32.B unilateral femoral shaft fractures operated with expandable or locked nail were evaluated retrospectively. We match patients who undergone expandable nail fixation with patients of the same-sex, age, and fracture type who undergone locked nailing. A match was done for 31 expandable nail. At follow up, healing was assessed radiologically and clinically. Outcome measures included duration of hospital stay, time taken to achieve bony union, and participation in full activities.
Results: The average duration of surgery in the expandable group was 60.9 min and in the locked group was 82.4 min. In the expandable group, the average clinical healing time was 15.5 weeks and radiographic healing time was 21.7 weeks. In the locked IMN group, the average clinical healing time was 18.4 weeks and the average radiographic healing time was 24.1 weeks. We observed seven (22.6%) non-union in expandable group and four (12.9%) non-union in locked group. In the expandable group, type of the fracture was AO 32.B in all of the non-union patients. We achieved union in all of non-unions of the locked group only with dynamization. In the expandable IMN group, five (16.1%) patients required major surgery, in the locked group none of the patients required major surgery.
Conclusion: Non-union rate of the expandable nail is higher than that of the locked nail for femoral diaphyseal fractures. It may be a treatment option in simple fractures like AO 32.A and in patients where rapid fixation is demanded. It has advantages of reduced operative time and less radiation exposure in comparison with reported series of conventional nails.
Keywords: Expandable nail, femur fracture, intramedullary nailing, self-locking