The viability of cryopreserved onlay cranial bone allografts: a comparative experimental study versus fresh autografts

It is well known that calvarial bone autografts are the bone grafts that are the least reabsorbent and have the best long-term evolution in craniofacial surgery. However, they do have certain limitations: (1) reabsorption results in repeated surgery and the need for new donor areas, (2) a limited amount of autogenous cranial bone is available (due to avoiding areas close to cranial sutures and venous sinuses, and because the temporal bone is very fragile and the cranium has not fully developed in children), and (3) graft extraction increases surgical time and morbidity. Because of this, we present an alternative to calvarial bone autografts: cryopreserved allografts. This paper is an experimental prospective study carried out on sheep with the following goals: (1) to assess the behavior of calvarial onlay bone grafts cryopreserved at -80 degrees C, using fresh autografts implanted under the same conditions as controls; (2) to compare reabsorption percentages statistically over time; and (3) to study qualitatively any histological variations. The results obtained are (1) more reabsorption of allografts when compared to autografts (at 90 days, 21.97% versus 20.21% of grafted volume), although this difference is not statistically significant; (2) a reduction in height in all onlay grafts as a consequence of the loss of the dipl?e; (3) the absence of any type of inflammation caused by a reaction to cryopreserved allografts; and (4) bone substitution performed using frozen allografts is histologically similar to that using fresh autografts.     

The fate of preserved autogenous bone graft

Certain clinical conditions exist in which a section of cranial bone is removed but not immediately replaced at the initial procedure. Preservation of this bone can provide a valuable autogenous donor source for a future reconstructive procedure. The purpose of our study was to compare the volume retention of fresh autogenous bone with that of preserved autogenous bone as inlay and onlay cranial grafts. Two bone grafts were harvested from the skull of 15 adult New Zealand White rabbits. The graft volumes were calculated, and the graft were preserved in a normal saline-antibiotic solution at -20 degrees C. Three months later, during the second procedure, a fresh graft was harvested and then placed in the preexisting occipital defect as an inlay graft. Also at this time, the preserved grafts were placed, one as an inlay graft in the fresh occipital defect and the other as an onlay graft in the frontal region. The animals were sacrificed 3 months later, and the percentage of graft volume retention was determined. The fresh inlay grafts had a mean volume retention of 85.1 percent, while the preserved inlay nad onlay grafts had 61.8 and 75.9 percent mean volume retention, respectively. It is concluded that while fresh cranial autograft remains the "gold standard" for craniofacial reconstruction, preserved autogenous cranial bone is a viable alternative for inlay and onlay grafting of the craniofacial region.     

Rehabilitation of patients with severely resorbed maxillae by means of implants with or without bone grafts. A 1-year follow-up study

Forty-three patients with severely resorbed maxillae who had been referred for implant treatment were assigned to one of three treatment groups: bone grafting and implant placement (graft group); modified implant placement but no bone grafting (trial group); or optimized complete dentures (no-implant group). Sixteen, 20, and 7 patients, respectively, were assigned to the three groups. At the 1-year follow-up, 10% of the implants had been lost. Only a few of the failures (3/22) occurred after prosthesis placement. The cumulative success rates were 83% in the graft group and 96% in the trial group. A substantial reduction of the grafted bone, especially of the onlay grafts, occurred in many patients. During the period from prosthesis connection to the 1-year follow-up, marginal peri-implant bone loss was on average 0.5 mm. Despite the often demanding procedures involved, all but one patient in each implant group said that they would undergo the treatment again. Most patients were very satisfied with the treatment outcome and their improved masticatory ability. Those who had renounced implant treatment appeared modestly adapted to their optimized dentures, but reported retention problems and less satisfaction with mastication.     

Changes in the aortic endothelium and plasma von Willebrand factor levels during the onset and progression of insulin-dependent diabetes in BB rats

The superior volume maintenance of membranous over endochondral bone has been shown in several studies and provides the basis for its preferred clinical use as an onlay grafting material in the craniofacial skeleton. The scientific rationale for this seeming embryologic advantage, however, has never been proven. Our hypothesis is that the pattern of onlay bone graft resorption is primarily determined by a graft's micro-architecture (relative cortical and cancellous composition) rather than its embryologic origin (membranous versus endochondral). Twenty-five adult New Zealand, White rabbits were used for this study. Eight animals were killed at 3 weeks, eight animals at 8 weeks, and nine animals at 16 weeks. Three graft types were placed onto each rabbit cranium: cortical bone graft of membranous origin and cortical and cancellous bone graft of endochondral origin. Fluorochrome markers were injected into all living rabbits at 1, 6, and 14 weeks. Microcomputed tomography scanning was performed on all of the bone grafts to determine postsacrifice volumes and to obtain detailed information regarding the bone graft's trabecular architecture. In addition, specimens were examined histologically. Volume analysis showed a statistically greater resorption rate in the cancellous endochondral bone graft than in either the endochondral or membranous cortical bone grafts (p < 0.05) for all time points. In addition there was no significant difference in the resorption rates between the endochondral and membranous cortical bone grafts. A post-test power analysis (alpha = 5 percent) of the volume data comparing the two types of cortical bone grafts showed that a difference in resorption of 8.9 percent would be detected with a 90-percent probability. Previous studies, which have shown a seeming superiority of membranous over endochondral bone grafts, used composite grafts composed of both cortical and cancellous portions. By separating these components, we have shown that cortical bone grafts maintain their volumes significantly better than cancellous bone grafts. In addition, we found no statistical difference in the resorption rates between the two cortical onlay bone grafts of different embryologic origins, a finding that has never been previously published. From our results, we believe cortical bone to be a superior onlay grafting material, independent of its embryologic origin. We believe these results challenge the currently accepted theories of bone graft dynamics and may lead to a change in the way clinicians approach bone graft selections for craniofacial surgery.     

Occipital calvarial bone graft in posterior occipitocervical fusion

STUDY DESIGN: Dorsal occipitocervical fusion is associated with a high rate of fusion failure and requires an additional surgical site for donor bone graft harvesting. In this series, an autologous occipital calvarial bone graft obtained from the same occipitocervical incision with contoured metal loops was used in 25 adults to achieve craniovertebral stabilization and fusion. OBJECTIVES: To study the use of autologous occipital calvarial bone grafts in occipitocervical fusion. SUMMARY OF BACKGROUND DATA: Cranial bone grafts have been used successfully in craniofacial reconstruction with good long-term results. In the plastic surgery literature, there are claims that membranous bone grafts are superior to endochondral bone grafts in fusions because of decreased resorption. In recent studies, results have shown successful use of calvarial bone in fusing the upper cervical spine in children. The use of autologous occipital bone in posterior occipitocervical fusions avoids many of the problems associated with traditional donor sites and provides a sufficient quantity of good quality bone for the fusion. This is especially true in the fragile rheumatoid arthritis patient with cranial cervical instability. METHOD: Split-thickness, autologous calvarial bone grafts with contoured loop and cable instrumentation were used for posterior occipitocervical stabilization and fusion in 25 patients, most of whom had rheumatoid arthritis. The calvarial bone graft was harvested from the occipital skull, using a microair impactor, and was secured next to the loop construct. After surgery, all patients were immobilized with external orthoses. RESULTS: None of the patients had hardware failure or complications from the occipital graft procurement. In 22 patients, good alignment, stability, and bony fusion were shown on radiographs. CONCLUSIONS: Occipital calvarial bone graft appears to work as well as other autologous corticocancellous bone grafts routinely used in posterior occipitocervical fusions.     

Biomechanical and histologic alteration of facial recipient bone after reconstruction with autogenous bone grafts and alloplastic implants: a 1-year study

Potential alteration of the underlying recipient bone resulting from a graft or implant has significant clinical relevance. The present study was designed to evaluate the biomechanical and histologic alteration of facial recipient bone with autogenous bone graft and alloplastic implants over a 1-year period. The bilateral arches of 15 rabbits were randomized between four groups: (1) control (n = 6), subperiosteal exposure of the zygomatic arch was made; (2) onlay (n = 12), bone graft was placed as an onlay to the zygomatic arch; (3) inlay (n = 6), bone graft was placed as an inlay within the zygomatic arch; (4) implant (n = 6), a stainless steel plate was placed as an onlay to the zygomatic arch. Animals were killed 1 year after grafting. In the onlay groups, all steel implants and half of the onlay bone grafts (n = 6) were separated from the zygomatic arch; the remaining onlay bone grafts (n = 6) were left on the zygomatic arch. Three-point breaking strength was measured through the center of the graft/implant site on the zygomatic arch, followed by histologic evaluation and histometric assessment of residual bone density. The findings demonstrated no difference in the breaking strength per unit bone area between the control zygomatic arch group and the onlay group in which the bone graft was left in place. Breaking strength of the zygomatic arch in the former two groups was significantly greater than that in either group in which the onlay bone graft or implant had been removed, and was also greater than the breaking strength in that group in which inlay bone had been placed (p < 0.05). Histologic assessment showed full-thickness conversion in architecture of the zygomatic arch from compact to woven bone beneath onlays of either autogenous bone graft or steel implant; histometric assessment demonstrated an accompanying decrease in bone density in the latter groups relative to the control zygoma (p < 0.05). We conclude that onlay autogenous bone graft and alloplastic implants to the facial skeleton induce transformation of both graft and recipient bone from compact to woven architecture, accompanied by a reduction in bone density. The biomechanical strength of recipient facial bone is significantly weakened if an onlay bone graft or implant is removed. Weakening occurs per unit area of remaining bone, and is therefore independent of any thinning that may occur within the recipient bone because of graft/implant placement. These findings may impact upon decisions to augment stress-bearing regions of the facial skeleton with bone graft or implants, particularly if the graft/implant may eventually require removal.     

Use of demineralized bone matrix in hindfoot arthrodesis

Fifty-five patients considering a hindfoot fusion performed by the senior author over a 5-year period were given the choice of having the fusion augmented by either iliac crest bone graft or demineralized bone graft in a study of the relative efficacy of these 2 methods of bone grafting. Eleven patients underwent subtalar fusion (average age, 40.1 +/- 14.0 years), and 44 had a triple arthrodesis (average age, 54.6 +/- 19.2 years). The most common indications for surgery were posterior tibial tendon insufficiency and traumatic arthritis. There were no significant differences between groups regarding underlying disease, medications, or associated medical conditions. In isolated subtalar fusions, all 3 patients who received an iliac crest bone graft experienced healing, as did 7 of 8 patients who received demineralized bone graft. The eighth patient had a radiographic non-union without clinical symptoms. Complete healing of triple arthrodeses was achieved in 13 of 15 patients who received an iliac crest bone graft and in 29 of 29 patients receiving a demineralized bone graft. There were no intergroup differences in the time to union, which generally was between 3 and 4 months. Intraoperative blood loss was significantly less with demineralized bone graft (33 +/- 25 ml) than with iliac crest bone graft (206 +/- 192 ml). This study demonstrated that demineralized bone graft aids arthrodesis at least as well as does iliac crest bone graft, without the increased blood loss, cost, and postoperative pain associated with iliac crest bone harvest.     

Experimental study on growth of epiphysial plate: free graft in rabbits

The growth potential of a free graft of an epiphysial plate was investigated in rabbits. Two epiphysial plate grafts were harvested from each iliac crest. One was grafted to the head (onto bone) and the other to the ear (onto cartilage). Both of the epiphysial plates enlarged to a maximum height of 1.4 cm and became similar to iliac crests. Enchondral ossification was observed up till approximately 28 weeks of age. We conclude that an epiphysial plate has growth potential after free heterotopic transplantation.     

Healing response to various forms of human demineralized bone matrix in athymic rat cranial defects

PURPOSE: This study compared the ability of a bone autograft and four distinct forms of human demineralized bone (DBM) to elicit bone repair in a critical size cranial defect in athymic rats. MATERIALS AND METHODS: Cranial defects were created in athymic rats and then grafted with either an autograft, rat DBM particles in glycerol (rGel), or one of four forms of human DBM: 1) hGel; 2) Putty (DBM fibers in glycerol); 3) Sheet (sheet of DBM fibers); or 4) Flex (DBM fiber sheet with glycerol). Histology, histomorphometry, and radiographic density of the graft sites were evaluated at 8 weeks. RESULTS: Of the grafted defects, 29% to 58% were found to be filled with new bone. The rGel and human forms of DBM stimulated similar amounts of new bone growth in comparison with the autograft-filled defects. The fiber-based grafts produced the largest amounts of new bone. CONCLUSIONS: Human DBM in gel, putty and sheet forms were found to perform as well as an autograft in a critical size cranial defect in the athymic rat.     

The Ranawat Award. Histology of nine structural bone grafts used in total knee arthroplasty

The cross section radiographs and histology of nine bone grafts were examined to determine whether grafts are durable enough to support a total knee implant when the load is shared by host bone, graft bone, and a stemmed component. All cases had cemented total knee arthroplasties with stemmed components adjacent to bulk grafts. The cases included autografts and allografts, which had been in situ for an average of 41 months (range, 20-62 months). Seven of the grafts were retrieved postmortem from three patients (four knees), and two were retrieved at revision surgery from one patient. The allografts all were intact, but had not revascularized. The autografts were viable bone. New bone was being laid down on the dead graft bone at the periphery of the allografts. No change in the bone to cement interface, no graft collapse, no development of radiolucent lines, and no component loosening occurred in these cases. The promising clinical results of bone grafts in total knee arthroplasties were confirmed by the examination of these grafts at the cellular level. Using stemmed components in bone grafted knee reconstructions may have increased graft durability and protected the grafts from fatigue failure.     

Cranioplasty with neovascularized autogenous calvarial bone

We have presented two cases of cranioplasty with neovascularized autogenous calvarial bone. A surgical procedure applying the principle of flap prefabrication has been applied to the preservation of autogenous calvarial bone obtained during external cranial decompression. The rectus abdominis muscle flap was elevated. A subcutaneous pocket was prepared for preservation of calvarial bone integrated with the rectus abdominis muscle. The outer cortex of calvarial bone was removed partially by bone chiseling. The muscle flap was attached to the bone graft by means of two holes on the bone by suture. The calvarial bone, grafted onto the rectus abdominis muscle flap, was inserted into the subcutaneous pocket. Several weeks later, the neovascularized calvarial bone flap was dissected along with inferior epigastric pedicle. Cranioplasty was performed using the bone element of the flap. Revascularization was achieved by anastomosing the inferior epigastric vessels to the temporal vessels. The postoperative films demonstrated marked radiolucency at the borders of the flap, although bone scan documented that the flap was vascularized. We speculate that the transferred bony segment was not completely vascularized.     

A comparison of vascularized and nonvascularized bone grafts for reconstruction of mandibular continuity defects

PURPOSE: This study compared vascularized and nonvascularized bone grafts for the reconstruction of segmental defects of the mandible. PATIENTS AND METHODS: The results in 39 patients having vascularized bone grafts (38 fibulas and one iliac crest) and 29 patients having nonvascularized bone grafts (26 iliac crest [22 corticocancellous block grafts, four cancellous bone grafts in a tray] and three rib grafts) for segmental mandibular reconstruction were evaluated in terms of overall success rate, total number of surgeries performed, total blood loss, total number of hospital days, and total number of hours in the operating room. RESULTS: Of 39 vascularized bone grafts, two failed (95% success rate), whereas of 29 nonvascularized bone grafts, seven failed (76% success rate). Failure for the nonvascularized bone grafts was closely correlated to the length of the defect. Nonvascularized bone graft patients underwent an average of one more surgical procedure for total reconstruction than vascularized bone graft patients, including osseointegrated implants. However, vascularized bone graft patients spent a mean of over 14 additional days in the hospital for all of their reconstructive procedures and an additional 3 hours in the operating room as compared with nonvascularized bone graft patients. Blood loss was similar in both groups (1,100 mL). Only 20% to 24% of patients in each treatment group have completed reconstruction to include osseointegrated implants. CONCLUSIONS: The success rate for vascularized bone grafting is high and is the treatment of choice when primary reconstruction is required, when the patient has been previously irradiated, or when simultaneous replacement of soft tissue is required. Vascularized bone grafts are also the treatment of choice for mandibular replacements over 9 cm in length. Nonvascularized bone grafts create a better contour and bone volume for facial esthetics and subsequent implant insertion, and may be the treatment of choice for secondary reconstruction of defects less than 9 cm in length.     

Prognostic factors and therapeutic options of radiotherapy in pediatric brain stem gliomas

BACKGROUND: Calvarial bone graft is often used in reconstructive cranio-facial surgery. As most common three different forms can be distinguished: outer-table bone, full thickness grafts and composite flaps (bone with a periostal or muscular pedicle). PATIENT AND METHOD: An extensive fibrous dysplasia of the frontal region was removed in a 26 years old patient. Reconstruction was carried out with alloplastic material achieving a good esthetic result. Recurrent seroma and occurrence of a fistula demanded removal of the alloplastic material and en-bloc reconstruction of the forehead region was accomplished with a parietal outer-table graft. Within a follow-up time of one year a good esthetic and stable reconstruction has been achieved. CONCLUSION: Split-thickness calvarial bone is still a versatile graft in reconstruction of the forehead region. Although a low rate of side effects in harvesting calvarial bone grafts are in general expected, one has to be aware of dural lesions occuring in the donor site during craniotomy.     

Split calvarial graft cranioplasty for the prevention of headache after retrosigmoid resection of acoustic neuromas

OBJECTIVE: This study describes the technique and efficacy of split calvarial graft cranioplasty for the reconstruction of retrosigmoid/suboccipital defects following surgery for acoustic neuromas. STUDY DESIGN: A prospective study of the technique of split calvarial graft cranioplasty, its postoperative healing, and incidence of postoperative headache. METHODS: The technique requires splitting of the craniotomy bone flap into outer and inner table bone grafts. The combination of both bony grafts allows the coverage of a wider area of posterior fossa dura. This technique was used in 18 patients. All patients were followed for a minimum of 6 months. Eleven of 18 patients were followed for 1 year or longer. Four patients had three-dimensional computed tomography of their skull and area of split calvarial bone graft. RESULTS: One of 18 patients had a persistent disabling headache at 1 year postoperatively. A natural contour of the retrosigmoid area was achieved in all patients. Three-dimensional computed tomography scan, obtained 6 months postoperatively, showed total coverage of the retrosigmoid area and fusion of the bone flap to the surrounding skull. CONCLUSION: The technique of split calvarial grafting of posterior fossa defects is a feasible, safe, and effective way of separating the nuchal musculature and posterior fossa dura. The technique also allows the restoration of the contour and bony covering of the retrosigmoid area. The technique is a simple alternative to other types of cranioplasties aimed at reducing the incidence of postoperative headache in patients with acoustic neuromas.     

Histologic analysis of clinically retrieved titanium microimplants placed in conjunction with maxillary sinus floor augmentation

In this study, a new approach involving placement and subsequent retrieval of titanium microimplants was employed for the histologic investigation of the implant-tissue interface in conjunction with maxillary sinus floor augmentation. Nine patients scheduled for sinus floor augmentation and simultaneous placement of Br?nemark implants were included in the study. After a sinus graft procedure and placement of implants, an additional microimplant was placed into the graft through the lateral wall of the sinus. At abutment connection, the microimplants were retrieved using a 3- or 5-mm-wide trephine drill. Six specimens were retrieved after 6 to 14 months from sites augmented with particulate radiated mineralized cancellous allograft. Another six implants were retrieved after 6 to 12 months from maxillary sinuses augmented with particulate autogenous bone grafts. The histologic analysis showed distinct differences between the two types of grafts. The sites with autogenous bones grafts displayed a normal morphology of bone and bone marrow, including formation of bone on the surfaces of the grafted particles and remodeling of newly formed as well as grafted bone. The bone was more mature after 11 to 14 months than at 6 months. The allografted sites had a mixed morphologic appearance of newly formed bone and nonviable allograft particles (about 75% of the total bone area) in loose connective tissue. Significantly more bone was found at the autografted than at the allografted implants. The use of autogenous bone for augmentation of the maxillary sinus floor resulted in a greater amount of viable bone surrounding the implant; however, simultaneous placement of implants apparently resulted in a low proportion of bone-implant contact after 6 to 14 months irrespective of graft type.     

A comparative study of osseointegration of titanium implants in autogenous and freeze-dried bone grafts

PURPOSE: This study was undertaken to compare the rate and degree of osseointegration of dental implants when placed into either autogenous corticocancellous chip or freeze-dried corticocancellous chip bone grafts. MATERIALS AND METHODS: The canine ilium was used as the model site. Thirty experimental and 15 control implants were placed in 15 dogs: autogenous versus freeze-dried corticocancellous chip bone grafts around the exposed implant surfaces. In addition to the placement of control implants, the apical portion of the grafted implants acted as their own control. The implants were harvested at 1, 2, and 3 months. The evaluation of the integration process was performed by means of light microscopy, microradiography, and histomorphometry. RESULTS: Using this model, the results indicate that at 1 month there was no statistical difference in the degree of osseointegration in the two bone grafts. At 2 months, there was a statistically greater degree of osseointegration noted in the autogenous corticocancellous chip sites than in the freeze-dried bone grafts. At 3 months, the degree of osseointegration in the two groups was 70% and 33%, respectively. At 3 months, there was virtually 100% integration with trabecular bone at the control implant sites. CONCLUSION: The results indicate that at 2 months postoperatively implants placed in an autogenous bone chip graft osseointegrate to a significantly greater degree than implants placed in a freeze-dried bone chip graft, and this difference remains at 3 months.     

Interrelations of soft and hard tissues for osseointegrated implants

Success in using osseointegrated dental implants-optimal function, esthetics, and phonetics-requires selection of the treatment modality that is optimal for the patient, protection of tissue blood supply, and adherence to a plan based on a thorough analysis of all deviations from the normal anatomy. The options for correction of hard-tissue deficiencies are mechanical modification of the implants and reconstructive surgery. Mechanical approaches reduce the time needed for reconstruction but direct the occlusal forces in unnatural directions. Surgical reconstruction is preferable. Any bone graft must be precisely fitted to the recipient site to facilitate revascularization. Restoration of hard-tissue dimensions usually requires soft-tissue coverage and augmentation. There are two basic options: (1) flaps with or without inlay or onlay grafts and (2) controlled tissue expansion. An onlay graft can help restore soft-tissue height and width. Inlay grafts have greater vascularity than onlay grafts, and the color matching is better. Controlled tissue expansion creates "like" tissue without a secondary defect, and fewer tissue transfers are needed. However, the technique is difficult, and the patient must make multiple visits to the office. For implant placement to be successful, the patient's expectations must be understood, and the benefit-to-risk ratio should be extremely high.     

Mandibular onlay grafting using prefabricated bone grafts with primary implant placement: an experimental study in minipigs

The aim of this experimental study was to evaluate the use of prefabricated autogenous bone grafts as onlay grafts to the mandible. Excess bone of 10 x 12 x 40 mm was produced inside blocks of pyrolyzed bovine bone under a polylactic membrane coverage on the outside of the mandible in 15 adult G?ttingen minipigs. After 5 months, this bone was harvested and transferred to the premolar region of the mandibular body in 10 animals. Onlay grafts of mandibular bone were used as controls for the transplanted prefabricated grafts. All grafts were fixed by primary placement of one titanium implant each. Five animals served as ungrafted controls. Evaluation was performed after 3 months and 5 months, respectively. Two animals were lost to evaluation, and one scaffold became infected. Eleven of the remaining 12 scaffolds showed sufficient bone ingrowth for grafting. Three months after transplantation, bone volume of the prefabricated grafts was almost completely preserved, with only minimal resorption in the superficial pores of the scaffolds, while the control grafts exhibited partial resorption. The titanium implants, which had been placed at the time of only grafting, exhibited direct bone-implant contact. Five months after grafting, all titanium implants showed complete osseointegration, with direct bone-implant contact. The grafted bone exhibited a significant increase in bone density by appositional bone formation. The control grafts were nearly completely resorbed at that time.     

Long-term effects of pentobarbital anesthesia on the atrial natriuretic peptide system in rats

The midline fascial splitting approach is a modified midline approach to the iliac crest for bone graft that takes advantage of the anatomic planes between layers of the dorsal lumbar fascia. Two hundred consecutive grafts were taken by this technique with one superficial infection, two cases of serous hematoma, and three patients with significant postoperative pain at the harvest site, for an overall complication rate of 3%. In comparison, bone grafts were harvested from 200 consecutive patients by the midline subcutaneous approach to the iliac crest with 2 deep infections, 1 cluneal nerve injury, 15 patients with severe and disabling pain at the harvest site, and 12 patients with a serous hematoma, for an overall complication rate of 15%. The midline fascial splitting approach significantly reduced the incidence of postoperative serous hematoma (P < 0.007) as well as the incidence of significant and disabling pain (P < 0.001). In addition, the approach is simple, straightforward, anatomic, and decreases trauma to soft tissues.     

Long-term follow-up of the vascularized iliac bone graft

We retrospectively studied four patients who were treated with vascularized iliac bone graft for reconstruction of the tibia. The average length of the graft was 9.8 cm. The follow-up period was 11-18 years (average, 14.8 years). Although two of them were osteomyelitis, no recurrence occurred. We also studied four patients who were treated with nonvascularized iliac bone graft for anterior spinal interbody fusion (average, 10.8 years). Cosmetic problem slightly exists because the vascularized iliac bone still showed the original shape, which was prominent from the tibial contour. The vascularized iliac bone marrow showed iso intensity in both T1 and T2 image of the MRI. However, nonvascularized iliac bone graft on the spine showed high intensity in both T1 and T2 imaging. Since the vascularized iliac bone graft does not present fatty degeneration, it shows strong resistance against infection.