Session VI - Pediatrics

Flexible Intramedullary Nailing of Femoral Shaft Fractures in the Skeletally Immature Patient: Flexible Titanium Nails versus Enders Nails

Brian A. Klatt, MD; Patrick Bosch, MD; Jan S. Grudziak, MD; Bruce H. Ziran, MD; Stephen Mendelson, MD, Children's Hospital of Pittsburgh, Dept. of Ortho Surgery; University of Pittsburgh, Pittsburgh, PA

Introduction: Flexible intramedullary nail (FIN) fixation for the treatment of femoral fractures in older skeletally immature patients (5 to 15 years of age) is minimally invasive, facilitates early mobilization, and decreases hospital stay. Previous studies have demonstrated low rates of complications, good outcomes, and cost savings with use of the FIN. Two predominant FIN systems are in use. The stainless steel Enders Nail (EN) is more rigid than the Flexible Titanium Nail (FTN), and the purpose of this study was to determine whether this difference in rigidity affects outcomes.

Methods: Records were reviewed of all patients treated with the two types of FIN at our institution since 1996, and 78 fractures were identified. Angular deformity, Winquist classification, fracture location, fracture type, time to union, angular deformity (AP and lateral), femoral rotational deformity (prone rotation test), knee range of motion, and leg-length discrepancy were recorded. In 38 patients (31 boys and 6 girls) with a mean age of 10.26 years, Enders Nails were used in 39 fractures: transverse 19, oblique 7, spiral 11, and segmental 1. Locations of the fractures were subtrochanteric 1, proximal third 12, mid-shaft 18, distal third 5, supracondylar 3; 23 fractures were classified as Winquist I, 7 as II, 1 as III, and 2 as IV. Flexible Titanium Nails were used in 39 fractures in 39 patients (30 boys and 9 girls) with a mean age of 10.26 years. There were 25 transverse, 2 oblique, 10 spiral, and no segmental fractures. The locations were subtrochanteric 2, proximal third 11, mid-shaft 14, distal third 10, and supracondylar 0. Fractures were classified as 30 Winquist I, 3 as II, 4 as III, and none as IV.

Results: There were no significant rotational deformities, knee motion limitations, or leg-length discrepancies, and few complications were seen in the series. Angulation on AP radiograph averaged 1.19 varus for the EN group and 3.22 varus for the FTN group (P = 0.09). Angulation on lateral radiographs averaged 3.22 apex anterior for the EN group and 9.75 apex anterior for the FTN group (P = 0.0001). No correlation was found with Winquist grade and angulation, with fracture type, or with fracture location and angulation because of a lack of sufficient numbers of fractures.

Conclusions: We found a significant difference in angular deformity with the different nailing systems. On the lateral radiographs, FTN had a significantly higher angulation. There was also a statistical trend to suggest that the AP deformity might be larger in the FTN group. With the more flexible FTN fixation, angular control is decreased. It is uncertain whether this deformity will ultimately remodel or presents a long-term deformity. Reevaluation of all the patients in several years will provide the answer.