Reconstruction of Oncologic Tibial Defects in Children Using Vascularized Fibula Flaps

Background: Tibial resection in children presents a unique reconstructive challenge due to technical demands, future growth potential and repetitive loading of the lower extremity. Positioned in a tibial defect, the free fibula undergoes primary bone healing while maintaining intrinsic resistance to infection and the ability to hypertrophy. Our aim is to evaluate surgical and functional outcomes in this selected group of pediatric patients.

Methods: This is a retrospective review of 13 consecutive pediatric oncology patients who underwent reconstruction of segmental tibial defects with intercalated vascularized fibula flaps from 1992-2007. Demographics, medical history and procedural characteristics were extracted from a prospectively maintained database and patient records review. Perioperative and long term complications were noted. Functional outcomes were analyzed.

Results: Thirteen patients with a mean age of 12.6 yrs (6-17 yrs ) were included. Nine patients were treated for sarcomatous lesions, each of whom underwent pre and postoperative chemotherapy. Four patients were treated for other neoplasms. Median followup was 63 mo (8-168 mo). Overall survival was 77%.

Mean defect size was 15.3 ± 4.5cm and mean fibula harvest length was 19.2 ± 4.7cm. Internal fixation was performed in 62% of patients, most of whom had diaphyseal lesions; 38% were fixated externally. One patient required immediate additional soft tissue coverage with local flaps and a skin graft.

Perioperative local complication rate was 23% (2/13) secondary to infection. Nonunion or delayed union occurred in 5/13 patients. Twelve fractures occurred in 7 patients; 83% healed with nonoperative management. Perioperative infection and chemotherapy did not significantly impact union or fracture rates.

Flap survival was 100%. Hypertrophy of the fibula approached native tibial size in 90% of surviving patients. Median time to union was 10 mo, time to partial weight bearing was 5.1 mo (2-10 mo) and time to full weight bearing was 16.8 mo (9-34 mo). Mean MSTS score was 27.1 ± 4. Of surviving patients, 91% achieved full weightbearing by 2 years, all of whom were ultimately able to participate in athletics.

Conclusions: Functional reconstruction of segmental tibial defects in children can be achieved safely and reliably with the vascularized fibula. Infectious complications are low, but problems with union and fracture at this lower extremity site can be common until graft hypertrophy occurs. Those who achieve disease control may ultimately enjoy an active lifestyle.