Session IX - Femur

Sat, 10/9/04 Femur, Paper #50, 4:03 pm

Trochanteric vs Pirformis Entry Portal for the Treatment of Femoral Shaft Fractures

William M. Ricci, MD¹ (a,e-Smith+Nephew);

John Schwappach, MD² (e-Smith+Nephew);

Kevin Coupe, MD³ (a,e-Smith+Nephew);

Michael Tucker, MD⁴ (a-Smith+Nephew); Angel Blackwell, MA¹ (n);

Ross K. Leighton, MD⁵ (a-Smith+Nephew);

Roy Sanders, MD⁶ (c,e-Smith+Nephew);

¹Washington University School of Medicine at Barnes-Jewish Hospital,

St. Louis, Missouri, USA;

²Swedish Medical Center, Seattle, Washington, USA

³University of Texas-Houston, Houston, Texas, USA;

⁴Medical College of Georgia, Augusta, Georgia, USA;

⁵Dalhousie University, Halifax, Nova Scotia, Canada;

⁶Florida Orthopaedic Institute, Temple Terrace, Florida, USA

Purpose: Antegrade femoral nailing through the tip of the greater trochanter, when performed with use of nails designed for piriformis entry, is associated with varus and iatrogenic comminution. Newer nail designs that facilitate insertion through the greater trochanter theoretically reduce the complications seen with straight nails inserted through this site. Trochanteric nailing is thought to be advantageous due to improved ease of insertion. However, there is little data to support this theoretic advantage. Furthermore, clinical outcomes after use of femoral nails specifically designed for trochanteric insertion compared with outcomes after nailing through the piriformis fossa remain unknown. The purpose of this study was to compare results of femoral shaft fracture treatment with use of a nail designed specifically for trochanteric entry, Trigen TAN, to results with use of an identical nail without a trochanteric bend inserted through the piriformis fossa, Trigen FAN.

Methods: A total of 108 patients treated for a femoral shaft fracture (OTA 32) were included in this prospective, multicenter (five level I trauma centers), Institutional Review Board-approved study. Four patients who died early in the postoperative period and 13 with insufficient follow-up were excluded from analysis. The remaining 91 patients were treated with either a Trigen TAN nail (N = 38, average age 28 years; one grade I, one grade II and two grade IIIA open) or Trigen FAN nail (N = 53, average age 29; two grade I, two grade II, and one grade IIIA open).

Results: Thirty-seven of the 38 fractures from the TAN group and 52 of the 53 from the FAN group healed after the index procedure. In all cases from both groups, there was <10° malalignment and no iatrogenic fracture comminution. The average operative time was 21% greater for piriformis insertion with use of the FAN nail (75 minutes) than for trochanteric insertion with use of the TAN nail (62 minutes), (P= 0.08). The average fluoroscopy time was 61% greater for the FAN group (153 seconds) than for the TAN group (95 seconds), (P <0.05). These difference were magnified in obese patients (BMI >30), for whom the operative time was 30% greater and the fluoroscopy time was 73% higher in the FAN group. Patients from both groups had similar baseline function (average LEM score: TAN group = 92, FAN group = 99) and similar initial decline and subsequent improvement in function over time.

Conclusion: A femoral nail specially designed for trochanteric insertion resulted in equally high union rates, equally low complication rates, and functional results similar to those of conventional antegrade femoral nailing through the piriformis fossa. As a result of increased ease of insertion, decreased operative time and decreased fluoroscopy time, the greater trochanter entry portal, coupled with an appropriately designed nail, represents a rational alternative for antegrade femoral nailing.