Prefabricated vascularized bone flap: a tissue transformation technique for bone reconstruction

In this study, an attempt was made to transform a muscle vascularized pedicle raised on host vessels into a vascularized bone flap, using recombinant human bone morphogenetic protein 2 (rhBMP-2). The purpose of this study was to produce new bone vascularized in nature to increase the survival rate of the subsequently grafted bone and to fabricate the newly formed bone into the desired shape. Silicone molds in the shape of a rat mandible were used to deliver rat bone matrix impregnated with or without rhBMP-2. A muscle pedicle the same size as the mold was raised on the saphenous vessels in the rat thigh and then sandwiched in the center of the silicone molds. The molds were sliced in half and each section was filled with rat bone matrix that was impregnated either with 25 microg of rhBMP-2 for the experimental group or with diluting material alone for the control group. The sandwiched flaps were then secured by tying them to the adjacent muscles and were harvested at 2 and 4 weeks after surgery. Three and six rats were used in the control and experimental groups at each time point, respectively. Bone formation was assessed in the ex vivo specimens by macroscopic, radiologic, and histologic evaluation. Macroscopically, the continuation of the vascular pedicle was clearly visible for both the control and experimental muscle flaps. However, no evidence of muscle-tissue transformation was observed in the control flaps, whereas all the flaps treated with rhBMP-2 produced new bone that replicated the shape of the mold exactly and had saphenous vessels supplying the newly formed bone. This study demonstrates that this experimental model has the potential to be therapeutically applied for effective bone reconstruction.     

Vascularized periosteum associated with cancellous bone graft: an experimental study

The association of a vascularized periosteal flap with a cancellous bone graft was studied on a group of 20 Wistar rats. Ten rats were sacrificed at 6 weeks and seven at 12 weeks (three died prematurely). The behavior of the cancellous bone graft buried in striated muscle and the osteogenic capacity of a simple vascularized periosteal flap also were observed on the same animals. Results of the study are as follows: In 14 of 17 animals, a vascularized periosteal flap wrapped around a cancellous bone graft resulted in new cortical bone formation with little resorption of the initial cancellous graft. A vascularized musculoperiosteal flap has produced a small amount of new compact bone only in 4 of 17 animals. A cancellous bone graft buried into well-vascularized muscle tissue was resorbed (15 cases) or necrotic (2 cases) at 12 weeks. In conclusion, the association of a vascularized periosteal flap and cancellous bone is a better means to produce compact bone than a vascularized periosteal flap alone or an isolated cancellous bone graft.     

Influences of vascularization and osteogenic cells on heterotopic bone formation within a madreporic ceramic in rats

Research in biomaterials for bone reconstruction has led to elaborate osteogenic composites that combine porous ceramics with bone marrow stromal cells. The aim of this study was to evaluate the influence of direct vascularization of such composites on osteogenesis and the ability to produce a vascularized bone substitute transplant in an ectopic muscular site. Sixty-four coralline biomaterials were implanted in 32 Fisher rats under four conditions: (1) alone (reference group M, n = 16), (2) coated with bone marrow stromal cells (group MC, n = 16), (3) combined with a vascular pedicle (group MV, n = 16), or (4) coated with bone marrow stromal cells and combined with a vascular pedicle (MCV group, n = 16). The number of vessels in the pores (vessel-pore ratio) of the implants and the proportion of pores showing bone ingrowth (bone-pore ratio) were measured at 2, 4, 6, and 8 weeks on four implants of each group. Compared with the reference group, angiogenesis was higher when the biomaterial was combined with a vascular pedicle or was coated with osteoprogenitor cells. The association of both vascular pedicle and osteoprogenitor cells increased vascularization by 60 percent (p = 0.003) and osteogenesis by 62 percent (p < 0.001). A combination of both vascular pedicle and bone marrow osteoprogenitor cells in coralline implants enhances neovascularization and osteogenesis after implantation in ectopic intramuscular sites to a greater extent than either does alone.     

The vascularized pig fibula bone flap model: effects of multiple segmental osteotomies on growth and viability

Previous work by this laboratory introduced the pig fibula bone flap as a model for the study of the pathophysiology of vascularized bone flaps. Anatomic and hemodynamic studies demonstrated a significant (p < 0.05) decrease in vascular perfusion after a series of segmental osteotomies and rigid fixation (lag screws and miniplates) in the distal end of the flap, suggesting that blood flow to the distal osteotomized segment of the flap may be impaired. Killing the animals after blood flow studies precluded assessment of the effect of these hemodynamic changes on bone healing. Therefore, the aim of this study was to assess the pig fibula bone flap model with respect to viability, healing, and subsequent growth after multiple segmental osteotomies and rigid fixation to contribute to the understanding of vascularized bone flap pathophysiology. Yorkshire pigs (20 to 25 kg) were used for all experiments. Eight pigs underwent unilateral elevation of a vascularized fibula bone flap, which was osteotomized into three segments and orthotopically rigidly fixed using a 2.4-mm mandibular reconstruction plate. The left fibula remained as the control. Fluorochrome labels were injected to assess bone viability and turnover, and both fibulae were assessed for growth radiologically. The fibulae were harvested 21 days postoperatively (when the animals were killed), and bone healing was assessed histologically and clinically. There were no significant differences in preoperative and postoperative lengths of the osteotomized fibulae compared with the controls, suggesting that there was no impairment of growth potential after multiple segmental osteotomies and rigid fixation. Significant (p < 0.05) bony hypertrophy of the osteotomized fibulae was noted when compared with controls. Mobility was observed in 3 of the 32 osteotomies (9 percent), occurring across one proximal and two distal osteotomies in association with failure of fixation. However, histologic and fluorochrome assessment confirmed the viability of all bone segments, as supported by the presence of tetracycline given 2 days postoperatively. The pig fibula bone flap model is well tolerated by the pig. Multiple segmental osteotomies and rigid fixation, previously associated with a significant decrease in blood flow in the distal segment, did not impair either growth potential, viability, or healing ability. It is suggested that the pig fibula is a suitable model for the study of bone flap pathophysiology.     

Outcome comparison in traumatic lower-extremity reconstruction by using various composite vascularized bone transplantation

Lower-extremity injury may present as a composite soft-tissue and bone defect, resulting directly from trauma or subsequent debridements. These composite defects often require vascularized osteocutaneous flaps for an effective, staged reconstruction. Among various donor sites, the vascularized fibular flap is generally considered the best option because of its inherent advantages. However, when the fibular flap is not available, iliac and rib flaps become the alternative choices. The purpose of this retrospective study was to compare the functional results of the alternatively chosen bone flaps (iliac and rib flaps) with those of the fibular flaps.     

One-stage reconstruction of composite bone and soft-tissue defects in traumatic lower extremities

Management of bone loss that occurs after severe trauma of open lower extremity fractures continues to challenge reconstructive surgeons. Sixty-one patients who had 62 traumatic open lower extremity fractures and combined bone and composite soft-tissue defects were treated with the following protocol: extensive debridement of necrotic tissues, eradication of infection, and vascularization of osteocutaneous tissue for one-stage bone and soft-tissue coverage reconstruction. The mechanism of injury included 49 motorcycle accidents (80.3 percent), five falls (8.2 percent), three crush injuries (4.9 percent), two pedestrian-automobile accidents (3.3 percent), and two motor vehicle accidents (3.3 percent). The bone defects were located in the tibia in 49 patients (79 percent; one patient had bilateral open tibial fractures), in the femur in seven patients (11.3 percent), in the calcaneus bone in four patients (6.5 percent), and in the metatarsal bones in two patients (3.2 percent). The size of soft-tissue defects ranged from 5 x 9 cm to 30 x 17 cm. The average length of the preoperative bony defect was 11.7 cm. The average duration from injury to one-stage reconstruction was 27.1 days, and the average number of previous extensive debridement procedures was 3.4. Fifty patients had vascularized fibula osteoseptocutaneous flaps, six had vascularized iliac osteocutaneous flaps, and five patients had seven combined vascularized rib transfers with serratus anterior muscle and/or latissimus dorsi muscle transfers. One patient received a second combined rib flap because the first combined rib flap failed. The rate of complete flap survival was 88.9 percent (56 of 63 flaps). Two combined vascularized rib transfers with serratus anterior muscle and latissimus dorsi muscle flaps were lost totally (3.2 percent) because of arterial thrombosis and deep infection, respectively. Partial skin flap losses were encountered in the five fibula osteoseptocutaneous flaps (7.9 percent). Postoperative infection for this one-stage reconstruction was 7.9 percent. Excluding the failed flap and the infected/amputated limb, the primary bony union rate after successful free vascularized bone grafting was 88.5 percent (54 of 61 transfers). The average primary union time was 6.9 months. The overall union rate was 96.7 percent (59 of 61 transfers). The average time to overall union was 8.5 months after surgery. Seven transferred vascularized bones had stress fractures, for a rate of 11.5 percent. Donor-site problems were noted in six fibular flaps, in two iliac flaps, and in one rib flap. The fibular donor-site problems were foot drop in one patient, superficial peroneal nerve palsy in one patient, contracture of the flexor hallucis longus muscle in two patients, and skin necrosis after split-thickness skin grafting in two patients. The iliac flap donor-site problems were temporary flank pain in one patient and lateral thigh numbness in the other. One rib flap transfer patient had pleural fibrosis. Transfer of the appropriate combination of vascularized bone and soft-tissue flap with a one-stage procedure provides complex lower extremity defects with successful functional results that are almost equal to the previously reported microsurgical staged procedures and conventional techniques.     

The role of the large superficial vein in survival of proximally based versus distally based sural veno-neuro-fasciocutaneous flaps in a rabbit model

A sural veno-neuro-fasciocutaneous flap in the New Zealand White rabbit was developed, and the role of the large subcutaneous lesser saphenous vein was investigated in proximally based versus distally based flaps. Retrograde dye injection showed that the lesser saphenous vein in rabbits has many valves with strong resistance against reflux. Twenty rabbits were randomly allocated into four groups of 10 flaps each. Group I consisted of proximally based flaps with the lesser saphenous vein intact (outflow) in the veno-neuro-adipofascial pedicle. Group II also consisted of proximally based flaps but the lesser saphenous vein was ligated at 1 cm proximal to the pedicle. Group III consisted of distally based flaps with the lesser saphenous vein intact (inflow) in the veno-neuro-adipofascial pedicle. Group IV also consisted of distally based flaps, but the lesser saphenous vein was ligated at 1 cm distal to the pedicle. The results showed that the mean flap survival area in group I (88.8 percent) was statistically higher than that in group II (62.6 percent, p < 0.001), and was higher in group IV (55.5 percent) than in group III (22.7 percent, p < 0.01). However, group II and group IV had no significant difference (p > 0.05). This experiment demonstrated that flap viability is determined by its intrinsic vascularization, both arterial and venous. The large superficial subcutaneous vein has a positive role (venous outflow) in proximally based flaps but a negative role (venous inflow) in distally based flaps. If the effect of the large subcutaneous vein is excluded, distally based flaps are not inherently inferior to proximally based flaps.     

Comparison of residual osseous mass between vascularized and nonvascularized onlay bone transfers

Composite flaps containing vascularized frontal bone were transferred on muscle pedicles in immature rabbits. Vascular continuity was maintained on one side and interrupted on the other. Bone weights at 16 weeks following transfer were compared with those of unoperated controls. The conventional bone graft demonstrated significant reduction in osseous mass. The vascularized bone maintained its mass compared with unoperated controls. Vascularized bone transfer appears to be the preferred surgical technique whenever possible.     

Osteocutaneous flap prefabrication in rats

Composite tissue defects may involve skin, mucosa, muscle, and bone together or in combinations of two or three of these tissues. Defects involving bone and skin are frequently encountered. Osteocutaneous flaps may be used to reconstruct these composite tissue defects. Sometimes, it is not possible to obtain a vascular osteocutaneous flap. Another way of producing an osteocutaneous flap that has the desired feature is prefabrication. Prefabrication of osteocutaneous flaps can be performed in two ways: (1) a vascularized osseous flap may be grafted with skin and (2) an osteocutaneous flap can be prefabricated by implanting an osseous graft into an axial island flap. There are many articles describing osteocutaneous flap prefabrication, but there is no comparison of both methods in the literature. As an experimental model for osteocutaneous flap prefabrication, rat tail bone was chosen. For the experiments, five groups were formed. Each group contained 10 rats. In the first experimental group, a vascularized osseous segment was skin grafted and an osteocutaneous flap was prefabricated. In the second experimental group, an osseous graft was implanted into an axial skin flap. To compare viability of skin and bone components of the two prefabrication groups, vascularized tail bone was elevated with overlying skin in the third group, a bone flap was elevated in the fourth group, and a skin flap that had been prefabricated by using vascular implantation was elevated in the fifth group. The authors examined five rats in each group by microangiography at the end of 4 weeks. On microangiographic analysis, all groups showed patency of vascular pedicles. There was no difference among the groups from the point of view of vascular patency and bone appearance. Bone scintigraphy was performed on the five rats in each group. On bone scintigraphic scans, the bone component of flaps was visualized in all groups except for group 5. The mean radioactivity value on the flap side was 10,362 +/- 541.1 in group 1, 10,241 +/- 1173 in group 2, 10,696 +/- 647.1 in group 3, and 10,696 +/- 647.1 in group 4. When the radioactivity values on the flap side were compared, no statistically significant difference among groups was seen, except for group 5 (p < 0.05). To evaluate bone metabolic activity, the bone component of flap and remaining last tail bone was harvested and the radioactivity of each specimen was measured with a well-type gamma counter. The parameter of percentage radioactivity in counts per minute per unit per gram of tissue was calculated. The value of the bone component of the flap side and the value of normal bone were estimated and results were compared. The mean result was 0.86 +/- 0.08 in group 1, 0.88 +/- 0.07 in group 2, 0.87 +/- 0.07 in group 3, and 0.81 +/- 0.04 in group 4. The difference among all groups was not statistically significant. Histologic examination was performed on all rats in each group and demonstrated that the bony component was viable, showing a cellular bone marrow, osteoblasts along bony trabeculae, and vascular channels in bone-containing groups. There were no significant microangiographic, histologic, or scintigraphic differences between the two experimental methods.     

Complications and vascular salvage of free-tissue transfers to the extremities

Complications were examined in 122 free flaps to lower and upper extremities in 104 patients, and vascular salvage was examined in 182 free flaps to lower and upper extremities in 158 patients. All patients were treated by the same surgeon. The overall survival rate of flaps was 96 percent. Complications occurred in 22 percent of the flaps. Complication rates were lower in patients with one free flap than in patients with two. Flaps had more vascular complications than nonvascular. Accompanying skin islands were found to be necessary to monitor vascularized bone transfers in order to avoid flap failure. Flow in the pedicle was reestablished in all flaps, but a higher percentage of flaps with longer ischemic times were lost. Although vascular compromise occurred frequently (15 percent), prompt surgical exploration and reexploration were thought to have greatly increased free-flap survival.     

Assessment of skin flaps using optically based methods for measuring blood flow and oxygenation

The objective of this study was to compare two noninvasive techniques, laser Doppler and optical spectroscopy, for monitoring hemodynamic changes in skin flaps. Animal models for assessing these changes in microvascular free flaps and pedicle flaps were investigated. A 2 x 3-cm free flap model based on the epigastric vein-artery pair and a reversed MacFarlane 3 x 10-cm pedicle flap model were used in this study. Animals were divided into four groups, with groups 1 (n = 6) and 2 (n = 4) undergoing epigastric free flap surgery and groups 3 (n = 3) and 4 (n = 10) undergoing pedicle flap surgery. Groups 1 and 4 served as controls for each of the flap models. Groups 2 and 3 served as ischemia-reperfusion models. Optical spectroscopy provides a measure of hemoglobin oxygen saturation and blood volume, and the laser Doppler method measures blood flow. Optical spectroscopy proved to be consistently more reliable in detecting problems with arterial in flow compared with laser Doppler assessments. When spectroscopy was used in an imaging configuration, oxygen saturation images of the entire flap were generated, thus creating a visual picture of global flap health. In both single-point and imaging modes the technique was sensitive to vessel manipulation, with the immediate post operative images providing an accurate prediction of eventual outcome. This series of skin flap studies suggests a potential role for optical spectroscopy and spectroscopic imaging in the clinical assessment of skin flaps.     

Effects of rhBMP-2 and osteopromotive membranes on experimental bone grafting.

A problem with using autogeneic bone for onlay grafting is its degree of incorporation and volumetric persistence. This study explored whether improved graft volumetric maintenance can be achieved by recombinant human bone morphogenetic protein-2 (rhBMP-2) and whether a combination of rhBMP-2 and osteopromotive membranes is advantageous in this respect. Unicortico-cancellous bone grafts were positioned below the temporal muscle bilaterally in 48 adult Lewis rats. The recipient bone was ground, and the grafted area was randomly treated according to one of eight different alternatives. Two doses of rhBMP-2 (4 microg/80 microl or 32 microg/80 microl buffer) in a collagenous carrier were tested, with or without coverage with expanded polytetrafluoroethylene membranes. As controls, membrane and carrier, alone or in combination, and onlay grafts only were used. The results were evaluated after 4 and 20 weeks by routine histologic examination and immunohistochemical labeling for various bone and cartilage matrix proteins. After 4 weeks, rhBMP-2-treated grafts showed complete integration, whereas for controls, only the membrane-alone group attained incorporation after 20 weeks. The combined treatment with high-dose rhBMP-2 and membrane demonstrated, as compared with the remaining rhBMP-2 groups, pronounced bone formation and less graft resorption, resulting in maintained or increased graft size. This was observed after 4 weeks, and the result remained at 20 weeks. Treatment with high-dose rhBMP-2 without membrane placement, in contrast, resulted in extensive resorption and graft size reduction at 20 weeks. Control groups showed less success in graft size persistence. It was concluded that a combination of high-dose rhBMP-2 and osteopromotive membranes had a synergistic effect, leading to rapid, complete graft integration and size maintenance. In the absence of a membrane, the protein seemed to accelerate the remodeling of the graft.     

Vascularized periosteal grafts: an experimental study using two different forms of tibial periosteum in rabbits

Three groups of rabbits were studied to investigate the osteogenic capacity of vascularized periosteum. It was found that such tissue, especially in the form of musculoperiosteal flaps, produced a significant amount of bone. It is concluded that vascularized periosteal flaps have an excellent osteogenic capacity even though they are not subjected to weight or stress.     

Effect of a freeze-dried CMC/PLGA microsphere matrix of rhBMP-2 on bone healing

The hypothesis of this research was that implants of poly(lactide-co-glycolide) (PLGA) microspheres loaded with bone morphogenetic protein-2 (rhBMP-2) and distributed in a freeze-dried carboxymethylcellulose (CMC) matrix would produce more new bone than would matrix implants of non-protein-loaded microspheres or matrix implants of only CMC. To test this hypothesis it was necessary to fashion microsphere-loaded CMC implants that were simple to insert, fit precisely into a defect, and would not elicit swelling. Microspheres were produced via a water-in-oil-in-water double-emulsion system and were loaded with rhBMP-2 by soaking them in a buffered solution of the protein at a concentration of 5.4 mg protein per gram of PLGA. Following recovery of the loaded microspheres by lyophilization matrices for implantation were prepared by lyophilizing a suspension of the microspheres in 2% CMC in flat-bottom tissue culture plates. Similar matrices were made with 2% CMC and with 2% CMC containing blank microspheres. A full-thickness calvarial defect model in New Zealand white rabbits was used to assess bone growth. Implants fit the defect well allowing for direct application. Six weeks postsurgery, defects were collected and processed for undecalcified histology. In vitro, 60% of the loaded rhBMP-2 released from devices or microspheres in 5 to 7 days. With the unembedded microspheres releasing faster than those embedded in CMC In vivo. the rhBMP-2 microspheres greatly enhanced bone healing, whereas nonloaded PLGA microspheres in the CMC implants had little effect. The results showed that a lyophilized device of rhBMP-2 PLGA microspheres in CMC was an effective implantable protein-delivery system for the use in bone repair. Published: October 7. 2001.     

A combined rectus abdominis musculocutaneous flap and vascularized iliac bone graft with double vascular pedicles

Although a free vascularized iliac bone graft has been successfully used for the reconstruction of large bone defects, there is a serious problem of how to repair in one stage patients having a large bone defect with a very wide skin defect. A free combined rectus abdominis musculocutaneous flap and vascularized iliac bone graft with double vascular pedicles seems to be one of the most suitable methods for patients having large defects of both bone and skin. Based on our patient, the main advantage of this flap is the extreme width of the skin territory. The pedicle vessels are large and long, and the donor scar can be made in an unexposed area. This flap should be considered for use in one-stage reconstructions of large defects of both bone and skin in the leg region.     

Evidence of in vivo osteoinduction in adult rat bone by adeno-Runx2 intra-femoral delivery

The bone marrow microenvironment provides a unique opportunity in vivo to assess the role of genes in bone remodeling. The objective of this study was to determine whether Runx2 expression is regulated by rhBMP-2 in vivo and to examine the effect of Runx2 overexpression on bone in vivo. In the in vivo calvaria model we used, rhBMP-2 induced Runx2 protein expression in periosteal cells while in vitro, adenovirus-mediated Runx2 overexpression induced mineralization in mesenchymal stem cells. A single injection of adeno-Runx2 directly into the bone marrow of the right femur in mature rats, and subsequent analysis after 3 weeks, showed a significant bone mineral density (BMD) increase ( approximately 15%) as compared to the controls. The whole-femur mean BMD of the active virus-injected group was 0.193 (g/cm(2)) while that of the control virus-injected group was 0.175 (g/cm(2)) (P < 0.05). In addition, a significant increase (36%) in trabecular BMD at the distal end of the femur was observed. These data demonstrate that directly delivering adeno-Runx2 into bone marrow of adult rats induces osteogenesis and illustrates potential advantages of such approaches over ex vivo gene therapy protocols involving marrow cell isolation, gene transduction, and subsequent in vivo transfer.     

Experimental comparison of bone revascularization by musculocutaneous and cutaneous flaps

Revascularization, one of the major components of bone healing, was examined in an experimental model. The radioactive microsphere technique demonstrated that after 4 weeks beneath a musculocutaneous flap, isolated bone segments had significant blood flow, whereas bone beneath a cutaneous flap did not. The muscle flap bone had a blood flow approximately half that of normal control bone. The muscle of the musculocutaneous flap had a blood flow three times that of the skin of the cutaneous flap. The bipedicle cutaneous flap used was designed to have a healthy blood supply, and at 4 weeks it had a blood flow twice that of control skin. Despite this, there was essentially no demonstrable blood flow in the cutaneous flap bone segments at 4 weeks. Only 3 of 17 bone segments underneath cutaneous flaps showed medullary vascularization, whereas 10 of 11 muscle flap bones did. All bone segments underneath muscle flaps showed osteoblasts and osteoclasts at 4 weeks; neither were seen in the cutaneous bone segments. The process of revascularization occurred through an intact cortex and penetrated into the cancellous bone. Because the bone segments were surrounded by an impervious barrier except for one cortical surface, the cellular activity seen is attributed to revascularization by the overlying flap. In this model, a muscle flap was superior to a cutaneous flap in revascularizing isolated bone segments at 4 weeks. This was documented by blood flow measured by the radioactive microsphere technique and by bone histology.     

Revascularized periosteal grafts--a new method to produce functional new bone without bone grafting

Rib periosteum was transplanted to the groins of 9 dogs. In half of the periosteal grafts, no microvascular anastomoses were done (free grafts); at 6 weeks after grafting they had become resorbed. The other periosteal grafts were revascularized by microvascular anastomoses of the intercostal vessels to local muscular vessels; at 6 weeks those with confirmed vascular patency had all formed substantial amounts of new bone. Five cm, full-thickness defects were created in the tibias of 10 dogs. The control animals (without grafting) did not heal in two months. However, the experimental dogs, with vascularized periosteal grafts in the defects regenerated their tibias with healthy new bone by 6 weeks--and were walking on them then.     

Free fibula long bone reconstruction in orthopedic oncology: a surgical algorithm for reconstructive options

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-sparing surgery, is a safe and reliable method with a predictable bony union, good functional outcome, and a low complication rate.