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.     

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.     

Free vascularized thin corticoperiosteal graft

This paper describes a new thin corticoperiosteal graft harvested from the medial condylar and supracondylar areas of the femur. It is based on the articular branch of the descending genicular artery and vein and consists of periosteum with a thin (0.5 to 1.0 mm) layer of outer cortical bone. By retaining the cortex, the cambium layer is preserved, and this is thought to have a better osteogenic capacity than vascularized periosteal grafts. This graft was used to treat six patients with fracture nonunion of the upper extremity in which conventional treatment had failed. Uneventful bony union was achieved in all patients within 10 weeks.     

Obliteration of decompressed frontal sinus by means of a deepithelialized island forehead flap

A new surgical procedure for the treatment of chronic unilateral suppurative frontal sinusitis was described. A vascularized composite tissue--forehead island flap--was used for obliteration of the decompressed left frontal sinus. In the author's opinion (in selected cases) it is more physiologically sound than the use of abdominal fat or bone graft as an alternative for obliteration. It will withstand the test of time, since myocutaneous flaps have been used reliably as vascularized tissues for anatomic regions troubled by infection and radiation.     

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.     

Fingertip reconstructions using partial-toe transfers

Fifty-six partial toes were transferred to reconstruct fingertip deficits. The transfers from the big toe mainly consisted of 3 trimmed big toetips, 3 vascularized nail grafts, 3 onychocutaneous flaps, 19 thin osteo-onychocutaneous flaps, and 2 hemipulp flaps. The transfers from the second toe mainly consisted of 8 trimmed second toetips, 5 reduced second toes, and 9 whole distal phalanges. The average values of postoperative sensory recovery of the osteo-onychocutaneous flaps including the vascularized nail grafts were 3.1 (Semmes-Weinstein test) and 6.3 mm (moving two-point discrimination) at 2.6 years after the transfer; those of the thin osteo-onychocutaneous flaps were 3.1 and 7.2 mm at 2.0 years after surgery; those of the trimmed big toe tip transfers were 3.61 and 6.5 mm at 1.8 years after surgery; and those of the trimmed second toetip transfers were 3.37 and 6.3 mm at 2.6 years after transfer. Those of the distal phalanx of the second toe were 3.41 and 7.9 mm at 1.2 years after surgery, and those of the reduced second toe were 3.2 and 6.7 mm at 10.6 months after surgery.     

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.     

The addition of muscle to the lateral arm and radial forearm flaps for wound coverage.

There is good evidence of the benefit of transferring vascularized muscle into wounds that are contaminated or have been infected previously. This benefit particularly applies in cavities around bones and joints. We present two patients in whom the inclusion of a portion of muscle in the lateral arm and radial forearm flaps allowed the effective combination of good-quality skin cover with the properties of vascularized muscle.     

The role of local fasciocutaneous flaps in total burn wound management.

The majority of acute burn wounds or delayed reconstructions are best managed simply with a skin graft. However, if vascularized tissue is mandatory, the local fasciocutaneous flap may have an important role in providing a single-stage technique for obtaining tissue nearly identical in color, texture, and consistency to that of the defect being restored. This review of 182 consecutive burn patients needing surgery found that they underwent 233 separate episodes for skin grafting. Appropriately, only a fraction of this number required some form of vascularized flap, with 14 patients having 21 local fasciocutaneous flaps. Six were elevated in previously skin-grafted regions, which is an advantage peculiar to this flap type. Three flaps (14 percent) suffered major complications requiring a second surgical intervention. Only six of all flaps were used for acute burn wounds, but two of the three complications accrued in this subset, with one directly attributable to wound infection. Since most flaps were required for either coverage or release of contractures about joints, it has been recommended that the initial surgical approach for treatment of the acute wound in these regions be altered to preserve the fascial plexus whenever possible to permit the use of this simple and expedient alternative if it is needed later.     

Combined anterolateral thigh flap and vascularized fibula osteoseptocutaneous flap in reconstruction of extensive composite mandibular defects.

Extensive composite defects of the oromandibular area are usually created after the surgical treatment of T3 and T4 cancers, requiring complex reconstructive plastic surgical procedures. The preferred treatment method for this type of defect is reconstruction with two free flaps. The use of the vascularized fibula osteoseptocutaneous flap for the bone and inner lining defect is well known and accepted. Among the flaps that can be used for the outer lining and soft-tissue reconstruction, the two most commonly used have been the forearm flap and the rectus abdominis myocutaneous flap. However, these flaps have some disadvantages that restrict their use for this purpose. The forearm flap is usually too thin to cover the fibular bone and reconstruction plate, and the rectus abdominis myocutaneous flap can cause a subclinical reduction in abdominal strength. Both radial forearm and rectus abdominis myocutaneous flaps are difficult to harvest during tumor excision. Because of these drawbacks, over the past several years the authors have preferred to use the anterolateral thigh flap for outer face, neck, and submandibular region reconstructions. From October of 1998 to June of 2000, 22 extensive composite mandibular defect reconstructions using the free anterolateral thigh flap, combined with the vascularized free fibula osteoseptocutaneous flap, were performed at the Chang Gung Memorial Hospital. Complete flap survival was 90.9 percent (40 of 44 flaps). Complete loss was seen in an anterolateral thigh flap, which was then reconstructed with a pectoralis major myocutaneous pedicled flap (2.3 percent). There were five venous problems: three in osteoseptocutaneous free fibula flaps, the other two in anterolateral thigh flaps; all were revised immediately. However, the skin islands of two osteoseptocutaneous free fibula flaps and one anterolateral thigh flap developed partial necrosis (6.8 percent). The other complications were compartment syndrome in the leg in one patient, external carotid artery rupture in one patient, three donor-site infections in two patients, three neck wound infections, and one myocardial insufficiency; all were treated properly. Thirteen patients underwent revision procedures 6 months after the first operation. These procedures included debulking of the flap or revision of the mouth angle or both. Trismus or intraoral contraction was noted in none of these patients. In conclusion, the free anterolateral thigh flap combined with the vascularized fibula osteoseptocutaneous flap seems to be a good choice in the reconstruction of the extensive composite defects of the oromandibular region aesthetically and functionally.     

Anatomic basis for vascularized outer-table calvarial bone flaps

The vascularization of the scalp and calvarium was studied in cadavers to better define the design of vascularized split- or full-thickness calvarial bone flaps. Selective dye injections of the superficial temporal and internal maxillary arteries established a horizontal and vertical network of vessels within and between each layer of the scalp. The periosteum of the frontoparietal region continues over the temporal aponeurosis as a separate, distinct layer, the innominate fascia, which is irrigated by numerous proximal branches of the superficial and deep temporal arteries. The periosteum can sustain the outer table of the calvarium by means of multiple small, vertical perforators. Between the periosteum and the outer table is a thin areolar layer of subperiosteum which continues beneath the temporal muscle. We feel that vascularized outer-table calvarial flaps can safely be pedicled using only the temporal aponeurosis, innominate fascia, and periosteum without including the galea or temporal muscle.     

Prefabrication of bone by use of a vascularized periosteal flap and bone morphogenetic protein.

The purpose of this pilot study was to prefabricate a vascularized bone graft by using a vascularized periosteal flap containing osteoprogenitor cells, a structural matrix, and recombinant human bone morphogenetic protein-2 (rhBMP-2). In a rat model, a periosteal flap vascularized by the saphenous artery and vein was dissected off the medial surface of the tibia. This flap consisted of three layers-periosteum, muscle, and fascia-and was tubed on itself to form a watertight chamber that was then transferred on its vascular pedicle to the groin. A total of 78 vascularized periosteal chambers were constructed in 39 animals and divided into 10 groups. In group 1, the periosteal chamber was left empty. Groups 2, 3, and 4 consisted of the periosteal flap and rhBMP-2, but in group 3, the proximal vascular pedicle was ligated, and in group 4, the flap was harvested without the periosteal layer and turned inside out. Groups 5 through 10 consisted of the vascularized periosteal flap containing several different structural matrices (calcium alginate spheres, polylactic acid, or demineralized bone matrix) with or without rhBMP-2. Animals were killed at 2, 4, or 8 weeks in each group. The presence and density of any new bone formation was evaluated both radiologically and histologically. Significant bone formation was seen only in those periosteal flaps containing rhBMP-2 and either the calcium alginate or polylactic acid matrix. New bone formation increased both radiologically and histologically from 2 weeks to 8 weeks only in the periosteal flaps containing the polylactic acid matrix and rhBMP-2. This preliminary study therefore suggests that four factors-blood supply, osteoprogenitor cells in the periosteal layer, a biodegradable matrix, and rhBMP-2-are required for optimal prefabrication of a vascularized bone graft.     

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.     

Peripheral neovascularization of muscle and musculocutaneous flaps in the pig.

Late loss of free muscle flaps following surgical or accidental trauma to the dominant vascular pedicle has been reported. In this study, time-dependent ligation of the dominant vascular pedicle was undertaken in denervated latissimus dorsi musculocutaneous or muscle-only island flaps in the pig. Muscle flaps were covered with a skin graft, and silicon rubber sheets were inserted between the flaps and their bases to simulate a poorly vascularized bed. Hemodynamic and viability studies were then performed using intravenous fluorescein (skin viability), tetrazolium blue (muscle viability), and radiolabeled 15-micron microspheres (capillary blood flow). Blood flow did not change in acutely raised musculocutaneous flaps (n = 10) but was significantly elevated in acutely raised muscle-only flaps (n = 10), suggesting that the skin paddle may steal blood flow from the underlying muscle in musculocutaneous flaps. Peripheral neovascularization at 1 day to 8 weeks was assessed (n = 30). Viability increased during the first week of revascularization and was not different in musculocutaneous and muscle-only flaps. Revascularization of muscle-only flaps was enhanced compared with musculocutaneous flaps in the 2- to 8-week period.     

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.     

Further experience with the lateral arm free flap

Our experience with the lateral arm free flap over the last 7 years was reviewed in detail, placing emphasis on the clinical aspects and modifications of the flap. A total of 150 patients have undergone reconstructive procedures with the flap for small to medium-sized defects. This included 18 split flaps, 11 osteocutaneous flaps, 6 with vascularized triceps tendon, 5 neurosensory flaps, and 5 fascia-fat flaps. The donor-site scar was generally acceptable; only 3 patients required scar revision and 15 patients required debulking of the flaps. With use of the split flap for wide defects, tension-free primary closure of the donor site can be achieved. In most cases, a two-team approach may be adopted, thereby increasing the efficiency of this microvascular transfer.     

Reconstruction of the eyebrow in the pediatric burn patient

We have reviewed our experience with reconstruction of eyebrow alopecia secondary to thermal injury in the pediatric patient. Reconstruction was performed with free composite strip grafts or vascularized island pedicle flaps. The complication rates for eyebrows reconstructed with vascularized island pedicles with respect to loss of a significant portion of the flaps (30.8 percent) and malalignment of the grafts (23.1 percent) were significantly greater (p less than 0.001) than the significant tissue loss (10.6 percent) or graft malalignment (7.9 percent) observed for free composite grafts. Hair density was more predictably restored with the free composite graft technique (p = 0.0004). The patients reconstructed with composite grafts had 89.4 percent acceptable results in contrast to 38.5 percent acceptable results obtained with the island pedicle technique. Based on these findings, we reserve the use of the vascularized island pedicle technique for male patients with unilateral alopecia and heavy hair density in the remaining eyebrow and in cases where free composite grafts have failed. The remaining patients are initially treated with free composite grafts with acceptable results in the overwhelming majority of cases.     

Growth potential in onlay bone grafts: a comparison of vascularized and free calvarial bone and suture bone grafts

Vascularized bone grafts are characterized by a viable cell population with osteogenic potential. These features suggest that continued growth can be anticipated following vascularized membranous bone transfer in a growing craniofacial skeleton. The present paper compares the potential for appositional bone growth in vascularized and free calvarial onlay bone grafts. In seven 8-week-old beagles, growth was assessed by direct caliper measurements of graft dimensions intraoperatively and 16 weeks postoperatively. Vascularized grafts demonstrated a 50 to 60 percent increase in size in all dimensions compared to 10 to 20 percent growth in free grafts (p less than 0.01). Microradiography revealed preservation of calvarial bony architecture and minimal resorption in vascularized grafts, while triple-fluorochrome labeling confirmed subperiosteal appositional bone formation. Free grafts were characterized by significant resorption and a delay in subperiosteal bone formation.     

A systematic approach for improvement of the donor sites of fasciocutaneous flaps

Fasciocutaneous flaps as a group have been maligned more often for fear of potential donor-site morbidity than any concern for reliability. Typically, this is related to limitations imposed by the skin graft necessary to close most such donor sites, as admittedly has been required for the majority (52 percent) of our 313 flaps over the past 2 decades. Nevertheless, 48 percent did not require skin grafts, reflecting the adoption of strategies that evolved to minimize this shortcoming. These included use of fascia-only flaps, primary closure with small composite flaps, direct closure possible by use of rotation or advancement flaps or a second flap, or a delayed closure utilizing either pretransfer or posttransfer tissue expansion. Donor-site complications were actually fewest when a skin graft or primary closure was possible and occurred at the same rate regardless of body region. However, because the skin-grafted donor site was always a cosmetic compromise, a systematic approach to circumvent its use whenever possible is emphasized as a valuable tool to enhance the role of fasciocutaneous flaps as a vascularized flap alternative.     

Neuromucosal prelaminated flaps for reconstruction of intraoral lining defects after radical tumor resection

To reconstruct intraoral lining defects after radical tumor resection by reinnervated vascularized mucosa, eight distal radial forearm flaps and two fibula flaps were prelaminated. Prelamination was performed by exposing the vascularized fascia, onto which the split distal end of a sural graft was fixed. The fascia and the sural nerve graft were covered by device-meshed mucosa or small full-thickness mucosa pieces. These structures again were covered by a Silastic sheet as large as the future flap, and the wound was closed by the elevated skin and subcutaneous tissue. Coverage by a Silastic sheet enabled mucosal spreading on the fascia, and the final flaps were thin, mucus-producing, and larger than the originally inserted mucosa. The 10 neuromucosal prelaminated flaps were harvested together with the inserted sural nerve graft after 8 to 10 weeks. During this time, the patient underwent radiotherapy and chemotherapy. Donor sites were closed directly by the preserved skin and subcutaneous tissue. Intraoral defects were reconstructed successfully by eight neuromucosal prelaminated distal radial forearm flaps and two neuromucosal prelaminated fibula flaps. The sural nerve grafts, inserted between the fascia and the mucosa, were coaptated eight times with the lingual nerve and two times with the inferior alveolar nerve. Intended reinnervation of the mucosa could already be proved clinically and histologically in the first two patients after 11 and 9 months. Preservation of skin and subcutaneous tissue considerably lowered donor-site morbidity. Neuromucosal prelamination enables reconstruction of intraoral lining defects by reinnervated mucus-producing tissue. Reconstruction of other mucosa-lined structures by this method seems feasible. Avoidance of skin islands for reconstruction lowers donor-site morbidity.