J Reconstr Microsurg 2010; 26(7): 481-486
DOI: 10.1055/s-0030-1261698
© Thieme Medical Publishers

Femur Flap for Tibial Reconstruction: Percent Circumference Required to Convey a Mechanical Advantage over the Fibula

Genevieve Broderick1 , Janice Lalikos1 , Matthew Chowaniec2 , Meghan Collins2 , Elias Wilson2 , Russell Babbitt1 , Julie O'Brien1 , Kristen Billiar2 , Raymond M. Dunn1
  • 1Department of Surgery, Division of Plastic and Reconstructive Surgery, University of Massachusetts Medical School, Worcester, Massachusetts
  • 2Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts
Further Information

Publication History

Publication Date:
30 June 2010 (online)

ABSTRACT

The fibula flap is commonly used to reconstruct the tibia. This has risk of postoperative fracture despite long-term non–weight bearing. A flap using noncircumferential distal femur is proposed. This study is to determine the circumference of femur required to produce greater strength than the fibular flap. Femurs and fibulas were harvested from eight cadavers. The structural strength of fibula and femur flaps was assessed using three-point bend. Compression testing was performed on osteotomized and whole femurs to assess donor site morbidity. The 35% flap (mean maximum force at fracture 869 N) was not significantly stronger than the fibula flap (626 N; p > 0.05). The 40% flap (1225 N) was significantly stronger than the fibula flap (p < 0.01). There was no significant difference between forces at fracture for whole femurs (3978 N), femurs with 35% osteotomies (3604 N), and femurs with 40% osteotomies (3493 N; p = 0.87). Change occurred in the fracture pattern of femurs following osteotomies. Whole femurs consistently fractured at the femoral neck, and osteotomized femurs consistently fractured obliquely from the osteotomy. A flap consisting of 40% of the circumference of the distal femur exceeds the structural strength of the fibular flap. Taking such a flap changes the femur's structural integrity; fixation may be prudent following harvest.

REFERENCES

Genevieve Broderick, M.D. 

Department of Surgery, Division of Plastic and Reconstructive Surgery, University of Massachusetts Medical School

55 Lake Avenue North, Worcester, MA 01655

Email: genevieve.broderick@umassmemorial.org