Abstract

The authors have retrospectively studied the results achieved with the AO/ASIF PFN system in the treatment of unstable intertrochanteric fractures of the proximal femur. Between June 1999 and February 2003, 51 patients with unstable intertrochanteric fractures of the proximal femur underwent intramedullary nailing with the PFN system. A total of 45 patients (28 women, 17 men, average age 72 years) with 46 unstable pertrochanteric fractures (21 31-A2, 25 31-A3,) were available for outcome analysis. Mean follow-up period was 20 months (range, 12 to 30). The Salvati and Wilson scale of hip function was used at the last follow-up clinical assessment. Intraoperative difficulties in the insertion of the nail or screws, fracture consolidation, technical or mechanical complications and delayed union, nonunion and avascular necrosis were registered as well. Solid union of the fracture was achieved in all patients except one who was revised to total hip arthroplasty because of avascular necrosis of the femoral head. Technical and mechanical complications were noted in 41.3% of the patients during the operation and in 30.4% at the follow-up period (2 cut-outs of the neck screw, 5 "Z effects" of the antirotational hip pin leading to femoral head protrusion in four of these cases, 1 case with reverse "Z-effect" and 2 implant failures, both revised to a long PFN implant). The overall rate of re-operation was 28.8%. The Salvati and Wilson score was > 25 in 27 (60%) of the patients. The PFN modifications might be responsible for the positive results in this study. Technical or mechanical complications seem to be related with the type of fracture, the operative technique and the time of weight bearing rather than the PFN system itself.