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.     

Transarticular bony defects after trauma and sepsis: arthrodesis using vascularized fibular transfer

Ten male patients with previously infected bony defects involving both sides of an articulation underwent arthrodesis using a vascularized fibular transfer. The average age of these patients was 38 years (range, 20 to 60 years). The size of the bony defect averaged 9 cm (range, 3 to 21 cm). The ankle was involved in five patients, the knee in two patients, the wrist in two patients, and the elbow in one patient. Nine cases represented septic pseudarthroses (eight after trauma and one after attempted ankle arthrodesis). One patient had a defect across the wrist after debridement of a chronic infection. The patients were followed for an average of 71 months (range, 26 to 144 months). Nine patients healed after the index vascularized fibular transfer, and one patient (ankle arthrodesis) required a second cancellous bone-grafting procedure for delayed union at the junction of the fibula with the talus. Four of seven patients with lower limb involvement had residual leg length discrepancies averaging 5 cm (range, 3 to 8 cm), and one had a persistent 20-degree internal rotation deformity. Two of the patients with upper limb involvement had stiff digits. Five of the nine previously employed patients returned to their former occupation (including heavy labor in four cases). Complications included two wound separations, one case of instability of the donor ankle after removal of a large fibular graft (related in part to a prior injury), and one fracture at the junction of the fibular graft with the local bone 10 months after the index procedure, which united after plate fixation and application of autogenous cancellous bone graft. Arthrodesis using a transfer of vascularized fibular bone represents a viable option for limb salvage in the face of an infected transarticular bony defect.     

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.     

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.     

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.     

Decreasing of residual alveolar ridge height in complete denture wearers. A five year follow up study

The resorption of the residual alveolar ridges is a chronic and continuous process of bone remodeling. The aim of this study was to analyse the rate of residual ridge resorption at different sites in the both jaws in complete denture wearers, through a five-year period of denture wearing. Residual ridge changes were measured on successive lateral cephalograms at 5 measurement points of the maxilla and the mandible. The first lateral radiograph was obtained at the delivery of complete dentures. The second lateral cephalogram was obtained after five years of denture wearing. Measurements were performed using a calibrated grid. The results of this study showed the existence of a significant alveolar ridge resorption at all five measurement points of the maxilla and the mandible. The observed variables, such as body mass index and the night time denture wearing had no significant influence on the rate of residual alveolar ridge resorption (p > 0.05). The duration of edentulousness had a significant influence on the rate of residual ridge resorption with significantly higher amounts of alveolar bone height decrease in those patients who had lost the last remaining teeth more recently.     

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.     

Evaluation of bone height in osseous free flap mandible reconstruction: an indirect measure of bone mass

Osseous free flaps have become the preferred method of mandibular reconstruction after oncologic surgical ablation. To elucidate the long-term effects of free flap mandibular reconstruction on bone mass, maintenance or reduction in bone height over time was used as an indirect measure of preservation or loss in bone mass. Factors potentially influencing bone mass preservation were evaluated; these included site of reconstruction (central, body, ramus), patient age, length of follow-up, adjuvant radiotherapy, and the delayed placement of osseointegrated dental implants. A retrospective analysis of patients undergoing osseous free flap mandible reconstruction for oncologic surgical defects between 1987 and 1995 was performed. Postoperative Panorex examinations were used to evaluate bone height and bony union after osteotomy. Fixation hardware was used as a reference to eliminate magnification as a possible source of error in measurement. There were 48 patients who qualified for this study by having at least 24 months of follow-up. There were 27 male and 21 female patients, with a mean age of 45 years (range, 5 to 75 years). Mandibular defects were anterior (24) and lateral (24). Osseous donor sites included the fibula (35), radius (6), scapula (4), and ilium (3). There were between zero and four segmental osteotomies per patient (excluding the ends of the graft). Nineteen percent of all patients had delayed placement of osseointegrated dental implants. Initial Panorex examinations were taken between 1 and 9 months postoperatively (mean, 2 months). Follow-up Panorex examinations were taken 24 to 104 months postoperatively (mean, 47 months). The bony union rate after osteotomy was 97 percent. Bone height measurements were compared by site and type of reconstruction. The mean loss in fibula height by site of reconstruction was 2 percent in central segments, 7 percent in body segments, and 5 percent in ramus segments. The mean loss in bone height after radial free flap mandible reconstruction was 33 percent in central segments and 37 percent in body segments; ramus segments did not lose height. The central and body segments reconstructed with scapular free flaps did not lose height, but one ramus segment lost 20 percent of height. There was no loss in bone height in mandibular body reconstruction with the ilium free flap. Fibula free flaps did not significantly lose bone height when evaluated with respect to age, follow-up, radiation therapy, or dental implant placement. The retention in bone height demonstrated in this study suggests that bone mass is preserved after osseous free flap mandible reconstruction. The greatest amount of bone loss was seen after multiply osteotomized radial free flaps were used for central mandibular reconstruction. The ability of the fibula free flap to maintain mass over time, coupled with its known advantages, further supports its use as the "work horse" donor site for mandible reconstruction.     

Growth and survival of vascularized and nonvascularized membranous bone: an experimental study

Although nonvascularized membranous bone grafts to the craniofacial skeleton demonstrate improved survival over similar grafts of endochondral origin, the comparative fate of vascularized membranous grafts is unknown. It is also unknown whether onlay membranous bone grafts in immature animals have the ability to grow. To examine these questions, a model was developed in New Zealand white rabbits in which a segment of the zygomatic arch was transferred to the subjacent mandible as either a vascularized or nonvascularized transfer. At harvest 16 weeks later, residual graft volume and bone architecture were analyzed. Results demonstrate no improved survival for vascularized membranous grafts in adult animals (n = 7), while in the immature animals (n = 6), growth of the vascularized bone transfers was documented. We conclude that in the majority of instances in craniofacial reconstruction, nonvascularized onlay membranous grafts are to be preferred. Specific instances for the use of vascularized transfers will be discussed.     

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.     

Vascularized fibular graft after excision of giant-cell tumor of the distal radius: wrist arthroplasty versus partial wrist arthrodesis

Several reconstructive procedures have been described for the complete defect of the distal radius that is created after a wide excision of a giant-cell tumor of bone, including hemiarthroplasty using the vascularized fibular head and partial wrist arthrodesis between a vascularized fibula and the scapholunate portion of the proximal carpal row. The objectives of this study are to compare clinical and radiographic results between the partial wrist arthrodesis and the wrist arthroplasty, and to discuss which procedure is superior. Four patients with giant-cell tumors involving the distal end of the radius were treated with en bloc resection and reconstruction with a free vascularized fibular graft. The wrists in two patients were reconstructed with an articular fibular head graft and the remaining two patients underwent partial wrist arthrodesis using a fibular shaft transfer. There was radiographic evidence of bone union at the host-graft junctions in all cases. In the newly reconstructed wrist joint, there was palmar subluxation of the carpal bones and degenerative changes in both patients. Local recurrence was seen in one patient. According to the functional results described by Enneking et al., the mean functional score was 67 percent. The functional scores including wrist/forearm range of motion in the cases with partial wrist arthrodesis were superior to those with wrist arthroplasty. A partial wrist arthrodesis using a vascularized fibular shaft graft appears a more useful and reliable procedure for reconstruction of the wrist after excision of the giant-cell tumor of the distal end of the radius than a wrist arthroplasty using the vascularized fibular head, although our study includes only a small number of patients.     

A torsional strength comparison of vascularized and nonvascularized bone grafts

Comparisons of torsional strength are made on the ulnae from the forelegs of short haired hounds where a nonvascularized graft was performed on one leg and a vascularized graft performed on the other. By using the forelegs of a dog as the experimental model and microsurgical techniques, a vascularized bone segment was used to graft a five centimeter nonunion in one leg and at the same time a conventional bone graft was performed on a similar nonunion in the other leg. Similar segments of rib bone were used for each graft. Torsional strength data are shown for nine experimental animals. A successful method for mounting the bones for testing of torsional strength in a torsion machine is given. In each case for which the bones healed properly, the vascularized bone graft proved to be significantly stronger in torsion.     

Treatment of craniomaxillofacial fibrous dysplasia: how early and how extensive?

Twenty-eight craniomaxillofacial fibrous dysplasia patients were treated as early as the symptoms occurred. The principles of surgical treatment were based on the zones of involvement: total excision of dysplastic bone of fronto-orbital, zygoma, and upper maxillary origin (zone 1) and bone reconstruction primarily; conservative excision on hair-bearing skull (zone 2), central cranial base (zone 3), and tooth-bearing bones (zone 4); and optic canal decompression on patients with orbital dysplasia and decreasing visual acuity. Patients were followed for 1 to 11 years (average 5.3 years). No recurrence or invasion of the fibrous dysplasia into the grafted bone was seen. One patient had orthognathic maxillary osteotomy on the reconstructed maxilla 6 years after initial reconstruction. Five of 19 patients with alveolar dysplasia had a recurrence and were reshaped. One patient had mandibular sagittal osteotomies to set back the prognathic, fibrous dysplasic mandible after three attempts at conservative shaving. Another patient with mandibular fibrous dysplasia had recurrence with pain and a hemimandibulectomy with successful immediate free vascularized iliac bone graft reconstruction.     

The role of cyclosporin in prolonging survival in vascularized bone allografts

It is known that experimental vascularized bone allografts are subject to host rejection. To be useful clinically, this rejection response would need to be controlled. Cyclosporin is a potent immunosuppressant whose precise role in vascularized bone allograft transplantation has not been established. Using a proven reliable vascularized knee allograft model in inbred rats, cyclosporin was used postoperatively both continuously and short term (14 days after transplant) at 10 mg/kg per day as recipient treatment. Across a strong histocompatibility barrier, continuous cyclosporin was required for long-term graft survival. Short-term therapy delayed rejection for 4 to 6 weeks. However, across a weak histocompatibility barrier, short-term therapy was as effective as continuous therapy in achieving long-term graft survival. The implication is that a limited course of cyclosporin may be clinically successful in sustaining vascularized bone allograft survival, provided the genetic disparity between graft and host has been minimized by genetic matching techniques.     

Functional reconstruction of maxilla with free latissimus dorsi-scapular osteomusculocutaneous flap

Restoration of oral and nasal function together with facial appearance is still challenging in maxillary reconstruction. Use of a composite flap transfer merely to fill the defect results in unsatisfactory functional and aesthetic outcomes. The authors present a reconstructive procedure for complex maxillary defects using the latissimus dorsi-scapular rib osteomusculocutaneous flap. Some modifications for the reconstruction of the nasal cavity and the hard palate contributed to excellent postoperative functions. Five cases of extended maxillary defect were reconstructed using a novel procedure between February of 1997 and October of 2000. The hard palate was reconstructed with a vascularized scapular angle. The infraorbital rim was reconstructed with a vascularized rib if it was required. A prop bone graft, replacing the zygomatic buttress, was added between the infraorbital rim and the hard palate. The latissimus dorsi muscle flap, which was supported by a skeletal framework and obliterated the remaining cavities around the bone grafts, was left exposed into the nasal cavity, and an 8-French (no. 10) nasal airway tube was placed as a stent in the nasal meatus for 3 weeks after surgery. A skin graft was applied on the scapular angle to reconstruct the oral side of the hard palate. If required, facial skin defect was repaired with a latissimus dorsi musculocutaneous flap or scapular flap. No major complications at the recipient or the donor sites occurred postoperatively in any of the five cases. In cases in which the eyeballs were preserved, almost normal facial appearance was obtained and an orbital extirpation case showed an acceptable postoperative appearance. All five patients returned to an unrestricted diet and their speech was assessed as normal by a speech test. Nasal breathing through the re-epithelialized meatus was possible in all cases. The reconstructed nasal cavity was maintained for more than 6 months in all cases and for more than 2 years in one early case. Rhinometry demonstrated normal function, and histologic findings of the re-epithelialized mucosa over the muscle flap in the nasal cavity revealed a nearly normal architecture. This technique simplifies the reconstructive procedure of massive maxillary defects, including those in the lateral wall of the nasal cavity. It also improves the postoperative oral and nasal functions of the patients.     

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.     

Bone reconstruction of the lower extremity: complications and outcomes

A study was performed to analyze the results and final outcomes of bone reconstruction of the lower extremity. Twenty-six patients presented with type IIIB open fractures, nine with type IIIC open fractures, and 15 with chronic osteomyelitis. Seven patients underwent primary amputation, and reconstruction was attempted for 43 patients. The mean bone defect size was 7.7 cm (range, 3 to 20 cm). Bone reconstruction was achieved with conventional bone grafts in 16 cases, in association with either local (13 cases) or free (three cases) flaps. Vascularized bone transfer was performed in 24 cases, with either osteocutaneous groin flaps (10 cases), soleus-fibula flaps (12 cases), or osteocutaneous lateral arm flaps (two cases). For three patients, bone reconstruction was performed with a technique that combines the induction of a membrane around a cement spacer with the use of an autologous cancellous bone graft. Infections were observed to be responsible for prolonged hospital stays and treatment failures. The cumulative rates of sepsis were 4.6 percent at 1 week after injury and 62.8 percent at 2 months. Vascular complications were also related to infections and were responsible for four secondary amputations. One patient asked for secondary amputation because of a painful nonfunctional lower limb. Bone healing occurred in 37 of 43 cases, and the average time to union was 9.5 months, with an average of 8.7 procedures. The mean lengths of stay were 49 days for conventional bone grafts and 62 days for vascularized bone grafts. All of the 50 patients were able to walk, with an average time of 14 months. All of the patients with amputations underwent prosthetic rehabilitation. Patients mostly complained about the reconstructed limb (62.8 percent). Joint stiffness was present in 40 percent of the cases. Other long-term complications were pain (nine cases), lack of sensation (five cases), infection (five cases), and pseudarthrosis (one case). However, all of the patients with successful reconstructions preferred their salvaged leg to an amputation. Of 41 patients who were working before the injury, 26 returned to work.     

Cystic echinococcosis of the pelvic bone with recurrences: a case report

Hydatid cysts commonly affect the liver and the lung. However, they rarely involve bones with vertebral column. We hereby report a case of a female patient with cystic echinococcosis of the hip bone and ilium. She presented with a long history of frequent recurrences highlighting the dismal prognosis at this rare site. Resection of the hydatid cyst from the sacroiliac region was done with allograft and autograft (rib graft) with lumbosacroiliac fixation. Follow-up of the patient at 6 months showed no detectable abnormality on radiology and the patient was doing well.     

Bone regeneration within a coralline hydroxyapatite implant.

The hypothesis that incomplete resorption of osteons in an autogenous cortical bone graft may limit its replacement by new bone regeneration was explored by implanting a hydroxyapatite replica of a coral skeletal structure into bone gaps. This implant contained channels and interconnections similar to those in osteon-evacuated bone grafts. In 6 implanted mandibular defects in dogs, two of which were examined at two, 4, and 6 months, 11 percent, 46 percent, and 88 percent of the implant areas were filled with regenerated bone. The regenerated bone was a woven type at two months, but changed to a lamellar type by 6 months. In two implanted defects examined at 12 months, biodegradation of 29 percent of the implant had occurred. The bone regeneration was physiological, the implant was biocompatible, and the biodegradation began after the bone had regenerated.     

Folded free vascularized fibula transfer

A technique of improved free vascularized fibula grafting for bone defects up to 15 cm in length is presented with three illustrative cases. By dividing a harvested free fibula graft at its midpoint without dividing its vascular pedicle, two vascularized bone lengths are produced that require only one set of anastomoses. This folded fibula provides twice the cross-sectional area of a single fibula transfer and allows biomechanically improved graft placement. This technique has been successfully used in long bone defects of the upper and lower limbs.