The fibula free flap became popular in orthopedic oncology for limb-sparing long bone tumor resection. It is particularly suitable for intercalary or resection arthrodesis options. In the present series, a surgical reconstruction algorithm was used, enabling each patient to receive a personalized technique. During the years 1998 to 2002, 30 patients underwent limb-sparing surgery for long bone sarcoma. There were 18 males and 12 females. Their mean age was 23 years (range, 9 to 70 years). The diagnoses were Ewing's sarcoma (11 patients), osteogenic sarcoma (eight patients), chondrosarcoma (five patients), giant cell tumor of bone (three patients), high-grade soft-tissue sarcoma (two patients), and leiomyosarcoma of bone (one patient). The majority of tumors where located in the lower extremity (23 patients), mostly in the femur (15 patients with four tumors in the proximal femoral shaft, five tumors in the distal femoral shaft, five tumors in the whole femoral shaft, and one tumor in the proximal femoral head). In seven patients, the upper extremity was involved; in six patients, the radius was involved; and in one patient, the humerus was involved. The free fibula flap was used in three types of approaches: vascularized fibula as an osseous flap only (18 patients), a combination of a vascularized fibula flap in conjunction with an allograft (Capanna's technique; 10 patients), and a free double-barreled fibula (two patients). All flaps survived. Postoperatively, all patients were monitored clinically, radiologically, and by radioisotope bone scan studies. Callus formation and union were shown 2.6 to 8 months postoperatively. Patients who underwent lower extremity reconstruction were nonweightbearing for 3 to 9 months, with a transition period in which they used a brace and gradually increased weightbearing until full weightbearing was achieved. Eight patients had 11 recipient-site complications. Two patients (6.7 percent) had hematomas, and three patients (10 percent) had infection and dehiscence of the surgical wound with bone exposure in one patient; all complications resolved with conservative treatment only. Failure of the hardware fixation system occurred in two patients, mandating surgical correction. No fibula donor-site complications were recorded. In intercalary resections, the use of the vascularized fibula flap as an isolated osseous flap might be insufficient. Different body sites have different stress loads to carry, depending on the age of the patient and on his individual physical status. To achieve initial strength in the early period, the authors combined the free fibula flap with an allograft (Capanna's method) or augmented it as a double-barreled fibula. They propose a surgical algorithm to assist the surgeon with the preferred method for reconstruction of various long bone defects in different body locations at childhood or adulthood. Long bone reconstruction using a vascularized fibula flap, alone or in combination with an allograft, autogenous bone graft, or double-barreled fibula for limb-s...