In situ splitting of a rib graft for reconstruction of the orbital floor.

A technique of in situ split rib graft harvest is described. It has been used in bone graft reconstructions of the orbital floor when small, thin, malleable grafts are desired. The advantages of in situ rib harvest are technical simplicity, diminished risks of known rib harvest-associated complications, and avoidance of the risks involved with in situ split cranial bone harvesting.     

Fixation effects on membranous and endochondral onlay bone graft revascularization and bone deposition.

This paper investigates the relationship between bone resorption, the process of bone revascularization, and graft fixation. Vital staining techniques and microangiography were used to study the extent of graft revascularization of fixed and nonfixed endochondral (rib) and membranous (skull) onlay bone grafts in 20 adult sheep mandibles bilaterally. This assessment was carried out at 2 and 20 weeks postoperatively. Sequential fluorochrome staining was performed to examine the pattern of new bone deposition. Fixation was achieved using the lagscrew technique. At 2 weeks, membranous bone demonstrated a greater area of graft revascularization if fixed than if the graft was not fixed. The opposite result was seen for endochondral grafts, where nonfixed grafts showed a greater area of revascularization than fixed grafts. At 20 weeks, all bone that was present was fully vascularized. The inconsistencies in the results on the relationship between fixation and revascularization for membranous and endochondral grafts in the early stages of healing (2 weeks) suggest that although revascularization is a necessary precondition for bone resorption and deposition, biomechanical and structural factors may be a more satisfactory explanation for the differences observed in the maintenance of bony volume.     

Fixation effects on membranous and endochondral onlay bone-graft resorption

Difficulties arise in the prediction of maintenance of graft volume over time when bone grafts are used for facial contour reconstruction. We hypothesize that graft fixation will decrease movement and lead to decreased resorption. Fixed and nonfixed endochondral (rib) and membranous (skull) onlay bone grafts measuring 30 X 10 X 4 mm were grafted to the mandible bilaterally in 10 adult sheep. Fixation was achieved using the lag-screw technique. Volume measurements using caliper technique were made 20 weeks postoperatively. The volume of graft present at 20 weeks was significantly greater for the fixed bone grafts (p less than 0.001): fixed membranous, 85.9 percent; fixed endochondral, 76.2 percent; nonfixed membranous, 55 percent; and nonfixed endochondral, 16.6 percent. The results are explained using biomechanical theories related to the effects of strain. At present, it is suggested by this study that when onlay bone grafts are stabilized, improved results with respect to graft resorption can be expected.     

Nasal reconstruction with full-thickness cranial bone grafts and rigid internal skeleton fixation through a coronal incision

The use of iliac and rib bone as onlay grafts to the nasal dorsum often fails because endochondral grafts resorb unpredictably. Membranous cranial bone grafts are less likely to resorb, especially when used with rigid internal fixation techniques. However, when split, they are often too thin and can be difficult to contour. Full-thickness cranial bone grafts were used to achieve nasal augmentation in 26 patients with end-stage nasal skeleton deficiency. All procedures were carried out using only a coronal incision. Grafts were harvested through a craniotomy, carved meticulously, and secured rigidly with miniplates or bicortical screws. Donor sites were reconstructed with split cranial grafts, leaving an intact cranial vault. No graft was lost to infection, and there was no significant donor-site morbidity. In carefully selected patients this method of full-thickness cranial bone graft reconstruction yields good results.     

Distraction osteogenesis of costochondral bone grafts in the mandible

Costochondral grafting for reconstruction of the Pruzansky type III mandible has given variable results. Lengthening of the rib graft by means of distraction had been advocated when subsequent growth of the grafted mandible is inadequate. This retrospective study reviews a series of patients with mandibular costochondral grafts who underwent subsequent distraction osteogenesis of the graft. A retrospective review identified two patient groups: group 1 consisted of individuals (n = 9) who underwent costochondral rib grafting of the mandible followed by distraction osteogenesis several months later at a rate of 1 mm/day. Group 2 consisted of patients with Pruzansky type II mandibles who had distraction osteogenesis without prior rib grafting (n = 9). The biomechanical parameters, orthodontic treatment regimens, and complications were examined versus patient age and quality of the rib graft. Distraction osteogenesis was successfully performed in six of the rib graft patients (group 1) and in all of the group 2 individuals. On the basis of the Haminishi scale, the computed tomographic scan appearance of the regenerate was classified as "standard or external" in six of the group 1 patients and as either "agenetic" or "pillar" (fibrous union) in the remaining three patients. In group 1, the average device was expanded 23 mm (range, 20 to 30 mm). Group 2 mandibular distraction results were all classified as either standard or external, and there was an average device expansion of 22.4 mm (range, 16 to 30 mm). The length of consolidation averaged 12.6 weeks in group 1, compared with 8.5 weeks in the traditional mandibular distraction patients (group 2). The mean shift of the dental midline to the contralateral side was 2.5 mm in group 1 versus 4.0 mm in group 2. Complex multiplanar and transport distractions were successfully performed on grafts of adequate bony volume. All four patients in group 1 with tracheostomies were successfully decannulated after consolidation. Rib graft distraction complications included pin tract infections in two patients, hardware failure with premature pin pullout in one patient, and evidence of fibrous nonunions in three young patients with single, diminutive rib grafts. In group 2, there were no distraction failures. Distraction osteogenesis can be successfully performed on costochondral rib grafts of the mandible; however, the complication rate is higher than in non-rib-graft patients. Performing the technique on older, more cooperative individuals seems to reduce this risk. In addition, placement of a double rib graft or an iliac bone graft of sufficient volume to create a neomandible with greater bone stock is an absolute requirement to decrease the risk of fibrous nonunion and provide a bone base of sufficient size for retention of the distraction device and manipulation of the regenerate.     

Augmentation of the atrophic mandible with a vascularized rib graft

A patient with a 29-year history of denture wearing had her mandible augmented with a vascularized rib graft. The rib was contoured to fit the arch of the mandible and vascularized by means of the facial arteries to the intercostal vessels. The nutrient artery was not included in the vascularized bone graft. Cortical cancellous bone chips were packed around the rib to augment the buccal surface of the rib graft. Periosteal perfusion and vascularity of the transferred rib were well documented at 1 week, 1 month, and 6 months postoperatively by radionuclide scintigraphy. It is now 24 months after surgery and the patient began wearing a denture 2 months after the rib transfer. She underwent a split-thickness skin graft vestibuloplasty and floor-of-the-mouth lowering 12 months following the rib transfer with improvement in her denture-wearing capabilities, which has remained constant for 10 months. Vertical resorption of the graft at 3 months was 10 percent, at 6 months 15 percent, and it has stabilized at 25 percent.     

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.     

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

The present study investigates transsutural growth in vascularized and free calvarial bone grafts and notes the effects of such growth on craniofacial development. The temporalis myoosseous flap served as a model of vascularized graft. In ten 8-week-old dogs, a standardized skeletal defect, including a segment of the zygomatico-maxillary suture, was created. The defect was reconstructed with a vascularized graft in half the animals and a corresponding free graft in the remaining animals. Growth was assessed by means of serial cephalometric radiography and direct osteometry. Vascularized bone grafts demonstrated persistent transsutural growth following transplantation. Growth at the recipient site was preserved, resulting in less restriction of vertical maxillary development.     

Use of Banked Tissue in Plastic Surgery

The availability of safe and reliable, banked tissues in India has enabled the use of human bone allografts as a viable alternative to autografts in reconstructive surgery. Lyophilised, irradiated bone grafts were used in 2 cases of rhinoplasty, a case of hemifacial atrophy, and as a chin implant.In the patient with revision rhinoplasty the rib graft was resorbed. The patient with hemifacial atrophy developed seroma and infection in the zygomatic and infraorbital area and the rib graft had to be removed. The graft from the same rib that was placed over the mandible was retained well and incorporated completely. The iliac crest cortico-cancellous grafts did well in the second case of augmentation rhinoplasty and in the augmentation of chin.The primary objective of reconstructive surgery in the treatment of burns, non-healing wounds and pressure sores is to remove the dead tissue and restore the continuity of the skin without delay. Lyophilised, irradiated, human amnion is a temporary biological dressing conveniently available off-the-shelf. It was used in twenty four patients with burns, eight patients with bedsores and six patients with non-healing ulcers mainly on the foot. The total surface areas of burns sustained were from 2% to 40%. The burns ranged from second degree to deep third degree burns. Amnion was not used in patients with infected third degree burns.The amnion provided good biological cover in all the patients. It was easy to handle and apply, and provided pain relief. The duration of healing varied depending on the extent and depth of the wound and the amount of exudate. The superficial bedsores healed with a single application of amnion. Reduced exudate, healthy granulation tissue and enhanced epithelisation were observed following application of amnion.     

Free bone graft reconstruction of irradiated facial tissue: experimental effects of basic fibroblast growth factor stimulation

A study was undertaken to evaluate the potential utility of basic fibroblast growth factor in the induction of angiogenesis and osseous healing in bone previously exposed to high doses of irradiation. Thirty New Zealand rabbits were evaluated by introducing basic fibroblast growth factor into irradiated mandibular resection sites either prior to or simultaneous with reconstruction by corticocancellous autografts harvested from the ilium. The fate of the free bone grafts was then evaluated at 90 days postoperatively by microangiographic, histologic, and fluorochrome bone-labeling techniques. Sequestration, necrosis, and failure to heal to recipient osseous margins was observed both clinically and histologically in all nontreated irradiated graft sites as well as those receiving simultaneous angiogenic stimulation at the time of graft placement. No fluorescent activity was seen in these graft groups. In the recipient sites pretreated with basic fibroblast growth factor prior to placement of the graft, healing and reestablishment of mandibular contour occurred in nearly 50 percent of the animals. Active bone formation was evident at cortical margins adjacent to the recipient sites but was absent in the more central cancellous regions of the grafts.     

Long-term remodeling of vascularized and nonvascularized onlay bone grafts: a macroscopic and microscopic analysis

The present study was performed to compare vascularized and nonvascularized onlay bone grafts to investigate the potential effect of graft-to-recipient bed orientation on long-term bone remodeling and changes in thickness and microarchitectural patterns of remodeling within the bone grafts. In two groups of 10 rabbits each, bone grafts were raised bilaterally from the supraorbital processes and placed subperiosteally on the zygomatic arch. The bone grafts were oriented parallel to the zygomatic arch on one side and perpendicular to the arch on the contralateral side. In the first group, vascularized bone grafts were transferred based on the auricularis anterior muscle, and in the second group nonvascularized bone grafts were transferred. Fluorochrome markers were injected during the last 3 months of animal survival, and animals were killed either 6 or 12 months postoperatively. The nonvascularized augmented zygoma showed no significant change in thickness 6 months after bone graft placement and a significant decrease in thickness 1 year after graft placement (p < 0.01). The vascularized augmented zygoma showed a slight but statistically significant decrease in thickness 6 months after graft placement (p < 0.003), with no significant difference relative to its initial thickness 1 year after graft placement. In animals killed 6 months after bone graft placement, both the rate of remodeling and the bone deposition rate measured during the last 3 months of survival were significantly higher in the vascularized bone grafts compared with their nonvascularized counterparts (p < 0.02). By 1 year postoperatively, there were no significant differences in thickness, mineral apposition rate, or osteon density between bone grafts oriented perpendicular and parallel to the zygomatic arch. These findings indicate that the vascularity of a bone graft has a significant effect on long-term thickness and histomorphometric parameters of bone remodeling, whereas the direction of placement of a subperiosteal graft relative to the recipient bed has minimal effect on these parameters. In vascularized bone grafts, both bone remodeling and deposition are accelerated during the initial period following graft placement. Continued bone deposition renders vascularized grafts better suited for the long-term maintenance of thickness and contour relative to nonvascularized grafts.     

Bone formation by revascularized periosteal and bone grafts, compared with traditional bone grafts.

Three groups of dogs were studied to compare the bone formation obtained with traditional bone grafting techniques, and that obtained with revascularized periosteum or revascularized bone grafts--all in unstressed bone. Revascularized periosteum did not produce a significant amount of bone in this unstressed model. At 4 months the revascularized rib grafts had a slightly greater tolerance to stress at the callus site than traditional bone grafts, but the incidence of non-union was the same. We conclude that the use of revascularized bone grafts should be reserved for situations in which traditional bone grafting techniques are unlikely to be successful.     

Combined conchal cartilage-ethmoid bone grafts in nasal surgery

Septal cartilage grafts are frequently required in rhinoplasties and nasal reconstructions. Unfortunately, sufficient septum is not always available for graft purposes. Conchal cartilage can serve as a substitute, but its usefulness is limited because of its soft, elastic nature. Applying thin sheets of pliable ethmoid bone to conchal cartilage gives the cartilage greater strength and, at the same time, allows it to retain some flexibility. This article examines the role of combined conchal cartilage-ethmoid bone grafts in nasal surgery. These grafts are simple to construct and are versatile in their application. By maintaining a free cartilage edge, they are readily sutured into place. The results seem to last long term.     

Volume maintenance of inlay bone grafts in the craniofacial skeleton

Although the clinical use of inlay bone grafts is widespread in craniofacial surgery, the dynamics of inlay bone grafting to the craniofacial skeleton have never been well characterized. Previous work demonstrated that volume maintenance of bone grafts in the onlay position is a consequence of their microarchitectural features, rather than their embryological origins. The purpose of this study was to investigate whether the properties determining the volume maintenance of bone grafts in the onlay position in the craniofacial skeleton could be extended to bone grafts in the inlay position. It was hypothesized that volume maintenance of an inlay bone graft could be better explained on the basis of the microarchitectural features of the graft (cortical versus cancellous composition), rather than its embryological origin (membranous versus endochondral), and that the primary determinant of bone graft behavior is the interaction between the microarchitectural features of the bone graft and the local mechanical environment in which the bone graft is placed. Cortical and cancellous bone grafts were harvested from the iliac crest (endochondral origin) of 25 New Zealand white rabbits, and cortical bone was harvested from the mandible (membranous origin) of each rabbit. Four 7-mm trephine holes were made in the cranium of each rabbit, posterior to the coronal suture. Each defect was filled with endochondral cortical bone, endochondral cancellous bone, or membranous cortical bone or was left as an ungrafted control specimen. Animals were killed at 3, 8, or 16 weeks. Crania were subjected to micro-computed tomographic and histological assessments. Micro-computed tomographic analysis demonstrated significant increases in actual bone volume from time 0 to the time of death for all types of grafts. Cortical bone demonstrated significant increases in space-occupying volume at all time points. By 16 weeks, no statistically significant difference in either the actual bone volume or the space-occupying volume according to graft type could be detected. There was no resorption of the inlay bone grafts; in fact, all bone types exhibited increased volume. Cancellous bone demonstrated the greatest capacity to increase actual bone volume. All bone graft types seemed to reach a steady-state bone volume, as if controlled by a local regulator. The regulator is likely the local mechanical environment in which the grafts were placed, as corroborated by the findings that the bone grafts seemed to recapitulate the characteristics of the bone in which they were placed, rather than maintaining their native characteristics.     

Bioactivation of free-fat transfers: a potential new approach to improving graft survival.

A new approach to free-fat autotransplantation resorption was evaluated experimentally in a rat animal model. Bioactive fat grafts were created by the addition of basic fibroblast growth factor delivered by dextran beads to the grafts and compared with free fat alone, free fat plus beads, and free fat plus beads and a control solution in the same animal. The grafts were assessed by weight and histology at 1 and 12 months postoperatively in 40 animals. A graded response in weight retention was observed at 1 and 12 months, with the growth factor-treated grafts exhibiting near complete weight maintenance after 1 year. All other bead-containing grafts had an intermediate response, with free fat alone averaging more than one-half graft weight loss after 1 year. Histologically, the bead-containing grafts had good fibroblastic ingrowth, but extensive intercellular collagen formation and the occurrence of small-sized adipocytes among the larger adipocytes were seen only in the growth factor-treated grafts. These findings indicate that graft manipulations that affect the preadipocyte cells of the graft or fibroblastic components of the recipient site, either through polypeptide stimulation or surface charge attraction, may offer a viable approach to postoperative fat-graft volume maintenance.     

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.     

A biomechanical comparison of vascularized and conventional autogenous bone grafts

Vascularized and conventional autogenous rib grafts were used to reconstruct 6-cm ulnar defects in the forelegs of the nine dogs. Each dog served as its own control. Biomechanical torsional testing of the grafted ulnas showed that vascularized grafts were 234 percent stronger than the conventional grafts. Bone toughness (energy absorbed) was 483 percent greater in the vascularized grafts, and elastic modulus and proportional limits were 263 and 246 percent greater, respectively. We conclude that vascularized bone grafts are significantly stronger than conventional autogenous bone grafts after 3 months of healing in the dog ulna model.     

A cadaveric analysis of the ideal costal cartilage graft for Asian rhinoplasty

Augmentation rhinoplasty of the Asian nose may be effectively accomplished with alloplastic materials. However, certain circumstances mandate the use of autologous grafts (e.g., dorsal augmentation that exceeds 8 mm and patient intolerance of alloplastic implants). Septal and auricular cartilages are inadequate for dorsal augmentation of the Asian nose. The use of costal cartilage for autologous augmentation in select Asian patients has proven to be a reliable method in more than 500 operative cases during a 10-year period. This study was designed to evaluate the ideal costal cartilage graft for augmentation rhinoplasty. Forty-two preserved cadavers were studied for the relationship of the individual rib cartilages to the surrounding tissue and for the length and caliber of each costal cartilage. The seventh rib was found to be the ideal rib graft by virtue of its safe location and overall size for grafting. The seventh rib is situated over the abdominal cavity, so the risk of pneumothorax is insignificant. The internal thoracic artery and vein descend in close apposition behind the first to sixth ribs but begin a course medial to the ribs inferior to this point, and therefore vascular injury during seventh-rib harvesting is unknown. The seventh rib also provides the greatest overall available length (90.7 mm, right; 89.6 mm, left) and thickness (17.6 mm, right; 17.5 mm, left). Despite the more conspicuous location of the incision required to harvest the seventh rib, the limited 3-cm incision that is used has healed favorably in almost all cases. The other major drawback for seventh-rib harvesting is the dissection required through the overlying rectus abdominis muscle, but little technical difficulty or postoperative morbidity is added with muscle dissection. The seventh rib is advocated as the ideal choice for augmentation rhinoplasty and potentially other recipient sites.     

The use of alloderm for the correction of nasal contour deformities

What rhinoplasty surgeon has not been frustrated by unmet expectations from unreliable graft materials? The quest for an ideal graft continues. Septal cartilage is not always adequate in amount or substance. Ear cartilage may cause unsightly irregularities over time. Cranial bone or rib harvest sites add to the complexity of the procedure and can be intimidating for many operators. This article describes the authors' successful experience with AlloDerm onlay grafts for the correction of nasal contour deformities in 58 primary and secondary rhinoplasty cases by means of the open and endonasal approaches. Forty-two patients received an open-approach procedure; the remaining 16 received grafting through an endonasal or closed approach. Thirty-seven of the patients were secondary rhinoplasty patients, and some underwent multiple nasal corrections. The indications, intraoperative surgical technique of graft placement, and representative results will be discussed. Long-term follow-up showed good results, though partial graft resorption occurred in some patients. Overall, this experience with AlloDerm for nasal augmentation was encouraging.     

The free vascularized anterior rib graft

The free vascularized anterior rib graft, one of the earliest free osseous transfers to the head and neck, has not gained widespread acceptance, perhaps due to early reservations concerning the adequacy of the periosteal circulation. The authors present further laboratory evidence, with clinical cases, attesting to the adequacy of the periosteal circulation alone. Our surgical technique varies from other reports in that a substantially greater length of the internal mammary vessels is harvested and includes the dual periosteal supply by means of the supracostal and intercostal vessels, both branches of the internal mammary vessels. This modification is based on anatomic and angiographic findings. The incorporation of both branches enhances the margin of safety in raising this free bone graft.