Showing papers on "Iliac crest published in 2003"

Is INFUSE Bone graft superior to autograft bone? An integrated analysis of clinical trials using the LT-CAGE Lumbar Tapered Fusion device

Abstract: Multicenter human clinical studies of patients undergoing anterior lumbar fusion have been conducted using recombinant bone morphogenetic protein or rhBMP-2 on an absorbable collagen sponge, marketed as INFUSE Bone Graft, or autograft implanted in the LT-CAGE Lumbar Tapered Fusion device. An integrated analysis of multiple clinical studies was performed using an analysis of covariance to adjust for preoperative variables in a total of 679 patients. Of these patients, 277 had their cages implanted with rhBMP-2 on an absorbable collagen sponge and 402 received autograft transferred from the iliac crest. The patients treated with rhBMP-2 had statistically superior outcomes with regard to length of surgery, blood loss, hospital stay, reoperation rate, median time to return to work, and fusion rates at 6, 12, and 24 months. Oswestry Disability Index scores and the Physical Component Scores and Pain Index of the SF-36 scale at 3, 6, 12, and 24 months showed statistically superior outcomes in the rhBMP-2 group.

A prospective, randomized, controlled cervical fusion study using recombinant human bone morphogenetic protein-2 with the CORNERSTONE-SR allograft ring and the ATLANTIS anterior cervical plate.

Abstract: Study Design. A prospective, randomized, pilot clinical trial compared recombinant human bone morphogenetic protein-2 (rhBMP-2) with iliac crest autograft bone for the treatment of human cervical disc disease. Objective. To examine the safety and effectiveness of using INFUSE™ Bone Graft (rhBMP-2 applied to an absorbable collagen sponge), as compared with an autogenous iliac crest bone graft placed inside the CORNERSTONE-SR™ fibular allograft, in anterior cervical discectomy and interbody fusion. Summary of Background Data. Recombinant human bone morphogenetic protein-2 is an osteoinductive protein that induces a reliable fusion in the lumbar spine, but it has not been studied in patients with degenerative cervical disc disease. Methods. For this study, 33 patients with degenerative cervical disc disease were randomly assigned to investigational or control groups. The investigational group received a fibular allograft (CORNERSTONE-SR™ Allograft Ring) with an rhBMP-2–laden collagen carrier inside the graft along with an ATLANTIS™ anterior cervical plate. The control group received a fibular allograft with cancellous iliac crest autograft placed inside it, along with an ATLANTIS anterior cervical plate. The patients underwent plain radiographs at 6 weeks, then at 3, 6, 12, and 24 months, and CT scans at 3 and 6 months after surgery. They also completed general health profiles and self-evaluation scales. Adverse events were evaluated for severity, duration, association with the implant, and the need for a second surgical procedure. Results. All the patients evaluated had solid fusions 6, 12, and 24 months after surgery. There were no device-related adverse events. At 24 months, the investigational group had mean improvement superior to that of the control group in neck disability and arm pain scores (P Conclusions. This pilot study demonstrates the feasibility of using rhBMP-2 safely and effectively in the cervical spine.

Effects of intermittent parathyroid hormone administration on bone mineralization density in iliac crest biopsies from patients with osteoporosis : a paired study before and after treatment

Abstract: Anabolic effects of PTH have been observed at several skeletal sites in humans by dual x-ray absorptiometry without differentiating between an actual increase in bone volume and an increase in mineral content within already established bone. The present study addressed this issue by evaluating the bone mineralization density distribution of iliac crest bone biopsies before and after PTH treatment for 18-36 months in men and women with osteoporosis using quantitative backscattered electron imaging. In cortical bone, pairwise comparison of the two biopsies before and after treatment revealed a reduction in the typical calcium concentration in men (-3.32%; P = 0.02, by paired t test), but no change in women, and the heterogeneity of mineralization increased in both males and females [+18.80% (P = 0.09) and +18.14% (P = 0.005), respectively]. In cancellous bone, there was no change in the typical calcium concentration, but there was a greater heterogeneity of mineralization in both men and women [+19.65% (P = 0.02) and +21.59% (P = 0.056), respectively] due to newly formed bone matrix. Small angle x-ray scattering performed on a subgroup of subjects revealed normal collagen/mineral structure. The findings confirm the observations that PTH stimulates skeletal remodeling, resulting in an increased percentage of newly formed bone matrix of lower mineral density.

Donor site morbidity in two different approaches to anterior iliac crest bone harvesting.

Abstract: BACKGROUND: Bone grafting is a surgical technique for the reconstruction of the atrophic edentulous maxilla prior to treatment with endosseous implants. The anterior iliac crest is a commonly used ...

Effect of regional gene therapy with bone morphogenetic protein-2-producing bone marrow cells on spinal fusion in rats.

Abstract: Background: Bone morphogenetic proteins (BMPs) are now being used as bone-graft substitutes to enhance spinal fusion. However, the large doses of BMP required to induce a spinal fusion in humans suggests that the delivery of these proteins should be improved. We used ex vivo adenoviral gene transfer to create BMP-2-producing bone marrow cells, and these autologous cells were found to induce a posterolateral fusion of the spine in syngeneic rats. Methods: Intertransverse spinal arthrodesis (L4 and L5) was attempted in ten groups of Lewis rats with 5 × 10 6 BMP-2-producing rat bone marrow cells (Ad-BMP-2 cells), created through adenoviral gene transfer with guanidine hydrochloride-extracted demineralized bone matrix as a carrier (Group I); 5 × 10 6 Ad-BMP-2 cells on a collagen sponge carrier (Group II); 10 μg of recombinant BMP-2 (rhBMP-2) in a guanidine hydrochloride-extracted demineralized bone matrix carrier (Group III); 10 μg of rhBMP-2 in a collagen sponge carrier (Group IV); autogenous iliac crest bone-grafting (Group V); 5 × 10 6 β-galactosidase-producing rat bone marrow cells, created through adenoviral gene transfer with guanidine hydrochloride-extracted demineralized bone matrix as a carrier (Group VI); decortication of the transverse processes alone (Group VII); 5 × 10 6 uninfected rat bone marrow cells with a guanidine hydrochloride-extracted demineralized bone matrix carrier (Group VIII); guanidine hydrochloride-extracted demineralized bone matrix only (Group IX); or a collagen sponge alone (Group X). Each specimen underwent plain radiography, manual palpation, and histological analysis. Results: All spines in Groups I and II (BMP-2-producing bone marrow cells) and all spines in Groups III and IV were fused at four weeks postoperatively. In contrast, none of the spines in the other groups had fused at a minimum of eight weeks after implantation. Histological analysis of the specimens revealed that the spines that had received BMP-2-producing bone marrow cells (Groups I and II) were filled with coarse trabecular bone postoperatively, whereas those that had received rhBMP-2 (Groups III and IV) were filled with thin, lace-like trabecular bone. All of the other spines, including those that had been treated with autogenous iliac crest bone-grafting (Group V), produced little or no new bone. Conclusion: BMP-2-producing bone marrow cells, created by adenoviral gene transfer, produce sufficient BMP to induce an intertransverse fusion in the rat spine model. Clinical Relevance: Regional gene therapy can be used to induce spinal fusion. This strategy with use of transduced bone marrow cells created through ex vivo gene transfer with a BMP-2-containing adenovirus could be adapted to enhance spinal fusion in humans.

Reduced iliac cancellous osteocyte density in patients with osteoporotic vertebral fracture.

Abstract: Iliac cancellous osteocyte density declines with age, but its relationship to vertebral fracture pathogenesis is unknown. We performed iliac bone biopsy in 44 women with clinical vertebral fracture and 56 healthy women. The fracture patients had 34% fewer osteocytes but no reduction in percent occupied lacunae. Some patients destined to sustain vertebral fracture make cancellous bone with fewer osteocytes. Introduction: Patient's with vertebral fracture have less bone than appropriate healthy controls, but other factors may contribute to bone fragility. Iliac cancellous osteocyte density declines with age in healthy women; we asked whether this variable differed between fracture patients and healthy controls. Methods: Two groups of women were assembled. Forty-four (mean age, 66.2 years) had unequivocal evidence of bone fragility manifested as painful nontraumatic vertebral fracture, and 56 (mean age, 62.2 years) were skeletally healthy. All subjects underwent iliac bone biopsy. From archival embedded biopsy cores, new sections were stained with Goldner's trichrome, in which we enumerated osteocyte-occupied lacunae (stained), empty lacunae (unstained), and total lacunae per bone area. Results: Cancellous osteocyte density was 34% lower in the fracture group than in the controls (p 90% for osteocyte density and 45 μm from the surface) were affected. In contrast, the age-related deficit is accompanied by an increase in empty lacunae and fall in percent osteocyte-occupied lacunae and occurs only in deep bone, but not in superficial bone. Conclusions: In some patients destined to sustain spontaneous vertebral compression fracture, iliac cancellous bone is made with fewer osteocytes than normal; the mechanism of osteocyte incorporation into bone needs more detailed study. Osteocyte deficiency could contribute to bone fragility, either by impairing the detection of fatigue microdamage or by reducing canalicular fluid flow. Current practices of defining vertebral fracture based on morphometry alone regardless of symptoms, and diagnosing osteoporosis based on bone densitometry alone regardless of fracture history, should be reexamined.

Treatment of nonunions and osseous defects with bone graft and calcium sulfate.

Abstract: The treatment of long bone nonunions and fractures with osseous defects is challenging. The results of 26 patients with either a persistent long bone nonunion or an osseous defect after an open fracture were reviewed. Each patient was treated with debridement of devitalized tissue, open reduction and internal fixation, and bone grafting using a mixture of autogenous iliac crest bone graft and medical grade calcium sulfate. The current study evaluated the union rate and associated complications for treatment of these injuries using this protocol. Each nonunion was confirmed intraoperatively, and healing was determined clinically by the patients' return to full activities without pain and radiographically by the presence of bridging trabeculae. Complications included persistent nonunion (four patients), wound drainage (five patients), wound drainage and cellulitis (one patient) and cellulitis alone (one patient). Using this treatment protocol, 22 patients (85%) achieved healing after one surgery and an additional two patients (92%) achieved healing after a second surgery. Medical grade calcium sulfate increases the volume of graft material, facilitates bone formation, and is safe in the treatment of nonunions and fractures with osseous defects.

Influence of PRP on autogenous sinus grafts. An experimental study on sheep.

Abstract: Since platelet -rich plasma (PRP) has been introduced to the field of oral surgery, it has become a widely accepted additive for bone regeneration treatment. The aim of this study was to evaluate the regenerative capacity of PRP in a sinus graft study on sheep. Twelve adult sheep underwent a bilateral sinus floor elevation procedure with cancellous bone from the iliac crest. Unilaterally, PRP was administrated to the bone graft. After 4 (six sheep) and 12 weeks (six sheep), bone biopsies were obtained from each site. With histomorphometric analysis we evaluated both the percentage of newly formed bone within the grafted site and the percentage of the contact area between the grafted bone and the newly formed bone. After 4 weeks the mean proportion of newly formed bone on the control side was 26.1%, whereas it was 29.2% on the test side. After 12 weeks it was 46.9% on the control side and 51.1% on the test side. The area of contact between the graft and the newly formed bone was 73.0% on the control side and 78.5% on the test side after 4 weeks, and 87.2% on the control side and 90.1% on the test side after 12 weeks. A statistical analysis did not reveal significant differences between the control and the test side. The results of the present experimental study show a regenerative capacity of PRP of quite low potency. Further basic research is needed to investigate more profoundly the possibilities of PRP in bone regeneration.

Simple carrier matrix modifications can enhance delivery of recombinant human bone morphogenetic protein-2 for posterolateral spine fusion.

Abstract: Study design A nonhuman primate lumbar intertransverse process arthrodesis model was used to evaluate modifications to a plain collagen sponge to deliver recombinant human bone morphogenetic protein-2 (rhBMP-2). Objectives To evaluate the feasibility of enhancing the delivery of rhBMP-2 with the established collagen sponge carrier by adding biphasic ceramic phosphate (BCP) granules (15% hydroxyapatite, 85% tricalcium phosphate) or allograft chips to provide compression resistance for posterolateral spine arthrodesis. Summary of background data Recombinant human bone morphogenetic protein-2 was successfully delivered with a resorbable collagen sponge in a rabbit intertransverse process fusion model. Success in nonhuman primates required a higher dose (6-9 mg) of rhBMP-2 and a more compression-resistant matrix (ceramic) than plain collagen. The limitation of the ceramic carrier was its radiopacity, which made radiographic detection of new bone formation difficult. Methods Nine adult rhesus monkeys underwent bilateral posterolateral intertransverse process arthrodesis at L4-L5. The animals were divided into three groups (n = 3 each) based on the graft material implanted: 1) autogenous iliac crest bone (5 cm3/side); 2) collagen sponge and 15:85 BCP granules loaded with rhBMP-2 (3 mg/side); and, 3) collagen sponge and allograft chips loaded with rhBMP-2 (3 mg/side). The monkeys were killed 24 weeks after surgery. Inspection, manual palpation, radiography, computed tomographic scans, and histology were used to assess fusion. Results All six monkeys with rhBMP-2 delivered in the collagen/15:85 BCP carrier and the collagen/allograft chips carrier achieved solid spine fusions, whereas only one of three animals fused with autogenous bone graft. Histologic analysis of the bone induced by rhBMP-2 showed normal trabecular bone and bone marrow elements. Conclusions The addition of either 15:85 BCP granules or allograft bone chips to the existing resorbable collagen sponge matrix enhanced delivery of rhBMP-2 in the posterolateral spine. The combination matrices were more compression resistant and had improved radiographic resorption properties that permitted easy radiographic visualization of new bone. In addition, a lower dose of rhBMP-2 (3 mg/side) was successful compared with the dose previously used with the plain collagen sponge (6 mg/side).

Management of alveolar clefts.

Abstract: The management of alveolar clefts has changed through the years as medical knowledge has improved. An alveolar cleft is the result of abnormal primary palate formation during weeks 4 to 12 of gestation. The rationale for its closure includes 1) stabilizing the maxillary arch, 2) permitting support for tooth eruption, 3) eliminating oronasal fistulae, and 4) providing improved esthetic results. Methods for closure of the alveolar cleft have been solidified during the last century with the use of bone grafting. Secondary bone grafting is now the preferred method of treatment, because early grafting has proven detrimental to midfacial growth. Various materials for bone grafting have been proposed, including iliac crest, cranium, tibia, rib, and mandibular symphysis. Regardless of the timing and materials used, the main principles in approaching alveolar clefts have been well described. They include 1) appropriate flap design, 2) wide exposure, 3) nasal floor reconstruction, 4) closure of oronasal fistula, 5) packing bony defect with cancellous bone, and 6) coverage of bone graft with gingival mucoperiosteal flaps. Certain alveolar clefts are difficult to manage by grafting alone, and orthodontic preparation may be required. Complications of alveolar bone grafts include donor site morbidity as well as graft exposure and loss.

Efficacy of autologous growth factors in lumbar intertransverse fusions.

Abstract: Study design and objectives A retrospective, consecutive series with "blinded" radiographic review was performed to evaluate two groups undergoing lumbar fusion: one with and one without autologous growth factors (AGF). Summary of background data AGF has been shown to promote bone formation in vitro and in vivo in animal studies. Accordingly, it has been promoted to augment lumbar intertransverse fusions. To date, however, no controlled studies have been performed to assess its ability to do so in humans. This article presents the first such study. Materials and methods Two groups were studied. The control group consisted of 27 consecutive patients who underwent a single-level intertransverse lumbar fusion using iliac crest bone graft for either degenerative disk disease (DDD) or degenerative spondylolisthesis from January 1999 to November 1999. The AGF group consisted of 32 consecutive patients undergoing an identical procedure for the same indications with iliac crest bone graft augmented with AGF from January 2000 to November 2000. Fusions were assessed radiographically at 1 and 2 years by two independent spine surgeons on AP and lateral flexion/extension radiographs. Results The fusion rate for the control group was 24 of 27, or 91%. The fusion rate for the AGF group was 18 of 32 or 62%. Conclusions In this study, the use of AGF resulted in inferior rates of arthrodesis compared with autogenous bone graft alone. Although it is important to note there are several techniques available to produce AGF and that the concentration of AGF may differ between individuals, based on the authors' findings, they cannot recommend the use of AGF for this indication until further clinical studies, perhaps altering these variables, prove otherwise.

Bone graft for revision hip arthroplasty: biology and future applications

Abstract: Revision total hip arthroplasty often presents surgeons with difficult bone loss problems. The selection of an appropriate bone graft is influenced by the size of the bone defect, the location, the biology of the bone graft site, and whether the graft is required for structural support. Autogenous bone graft remains the gold standard bone graft material but there only is a limited amount available and there is morbidity associated with the harvesting of these grafts. The most frequently used bone graft materials include autogenous iliac crest bone graft, cancellous allograft chips, demineralized bone matrix, and bulk structural allografts (femoral head, distal or proximal femoral allograft, whole acetabuli, and femoral strut grafts). It often is difficult to determine on plain radiographs whether nonstructural grafts actually incorporate into the host bone. Recently, attention has focused on the use of new materials for bone grafting including: new demineralized bone matrices, ceramics, autologous platelet concentrates, recombinant proteins, and stem cells. The purpose of this review was to assess the biologic potential of these nonstructural grafts in revision hip arthroplasty and their limitations. Are these agents actually incorporating into host bone? Future bone graft options, including tissue engineering and gene therapy will be discussed briefly.

A pilot safety and efficacy study of OP-1 putty (rhBMP-7) as an adjunct to iliac crest autograft in posterolateral lumbar fusions

Abstract: The ability of bone morphogenetic proteins (BMPs) to induce bone formation has led to an increasing interest in the potential for their use in fusion surgery. The purpose of this multi-center clinical pilot study was to evaluate the safety of one such BMP—osteogenic protein 1, in the form of OP-1 putty—combined with autograft for intertransverse process fusion of the lumbar spine in patients with symptomatic spinal stenosis and degenerative spondylolisthesis following spinal decompression. Twelve patients with spinal stenosis and degenerative lumbar spondylolisthesis underwent laminectomy and partial or complete medial facetectomy as required for decompression of the neural elements followed by intertransverse process fusion by placing iliac crest autograft and OP-1 putty between the decorticated transverse processes. No instrumentation was used. Patients were followed clinically using the Oswestry scale and radiographically using static and dynamic radiographs to assess their fusion status. Independent and blinded radiologists assessed the films for the presence of bridging bone between the transverse processes and measured translation and angulation on dynamic films using digital calipers. In addition to bridging bone, less than or equal to 5° of angular motion and less than or equal to 2 mm of translation were required to classify the patients as successfully fused, as per the definition of successful fusion provided by the FDA for use in clinical trials involving investigational devices to attain spinal fusion. Radiographic outcome was compared to a historical control (autograft alone fusion without instrumentation for the treatment of degenerative spondylolisthesis). All adverse events were recorded prospectively. The results showed 9 of the 12 patients (75%) obtained at least a 20% improvement in their preoperative Oswestry score, while 6 of 11 patients (55%) with radiographic follow-up achieved a solid fusion by the criteria used in this study. Bridging bone on the anteroposterior film was observed in 10 of the 11 patients (91%). No systemic toxicity, ectopic bone formation, recurrent stenosis or other adverse events related to the OP-1 putty implant were observed. A successful fusion was observed in slightly over half the patients in this study, using stringent criteria without adjunctive spinal instrumentation. This study did not demonstrate the superiority of OP-1 combined with autograft over an autograft alone historical control, in which the fusion rate was approximately 45%. The lack of adverse events related to the OP-1 putty implant in this study is in agreement with other studies supporting the safety of bone morphogenetic proteins in spinal surgery.

Comparison of bone grafts for posterior spinal fusion in adolescent idiopathic scoliosis

Abstract: Study design A retrospective comparison of three different types of bone grafts for posterior spinal fusion in adolescent idiopathic scoliosis. Objective To determine the efficacy of bone marrow and demineralized bone matrix as a bone graft substitute for spinal fusion. Summary of background data Several reports have documented a high morbidity associated with harvesting autologous iliac crest bone graft (ICBG) for spinal fusion. Composite bone graft consisting of demineralized bone matrix and aspirated bone marrow may reduce the morbidity and still retain the osteoinductive properties of iliac crest autograft. Methods Three different bone grafting techniques were used by a single surgeon in 88 consecutive patients who had posterior spinal fusion for adolescent idiopathic scoliosis. Segmental instrumentation with dual-rod fixation was used in all cases. Selection of type of graft was determined historically by the time when the operations were performed. Autologous ICBG was used in Group A, freeze-dried corticocancellous allograft in Group B, and composite graft of autologous bone marrow and demineralized bone matrix in Group C. Seventy-seven patients were reviewed, with a minimum of 2 years' follow-up (mean, 3 years 7 months; range, 2 years-9 years 5 months). Radiographs were assessed for pseudarthrosis and loss of correction of 10 degrees or more. Loss of 10 degrees of correction has been previously identified as an indicator of potential pseudarthrosis or fusion instability. Both of these criteria were used to compare success of fusion. Results Failure caused by pseudarthroses was seen in two patients (2.6%), one in Group A and one in Group B. Eleven patients lost greater than 10 degrees of correction, but only one demonstrated pseudarthroses. The 13 patients with pseudarthroses or loss of correction constitute the failure group for purposes of graft assessment. The failure rate was 12.5% in Group A (ICBG), 28% in Group B (freeze-dried corticocancellous allograft), and 11.1% in Group C (composite graft of autologous bone marrow and demineralized bone matrix). Eliminating patients with crankshaft phenomenon did not substantially change the results. There was no morbidity associated with bone marrow aspiration. Conclusions Fusion rates were comparable for GroupA (ICBG) and Group C (composite graft of autologous bone marrow and demineralized bone matrix). The composite graft is our preferred graft for fusions in adolescent idiopathic scoliosis.

Complications of iliac crest graft and bone grafting alternatives in foot and ankle surgery.

Abstract: The ability to harvest iliac crest bone is a well-established skill in the surgical armamentarium of the orthopedic surgeon. As with any surgical procedure, this operation has its own set of complications. The surgeon must be aware of these potential problems in an effort to avoid them when possible. Other autologous sites for bone harvest are available to the surgeon, and s/he should be aware of these in terms of location, limitations of use, harvest technique, and potential pitfalls. The foot and ankle surgeon almost always needs less bone graft than our colleagues in spine surgery or joint revision surgery, so these other sites may be more suitable than the iliac crest for obtaining bone graft. Nonautogenous alternatives are becoming increasingly available to the orthopedist as a way to decrease morbidity and operating times. Scranton recently published an article about his success with several different bone substitute products that are used in foot and ankle reconstructive cases. As these options become more varied, it becomes more difficult to know which product to select. Understanding the biology of bone grafting with respect to osteoconduction, osteoinduction, and osteogenesis provides the surgeon with the knowledge that is needed to make an informed choice when selecting a bone grafting option. Before choosing an alternative graft material, the surgeon should also investigate how the graft material has performed in cases similar to his or her patient's needs. In the future, with continued research, the fields of tissue engineering and gene therapy will provide even better options for nonautogenous bone graft material.

A cost analysis of bone morphogenetic protein versus autogenous iliac crest bone graft in single-level anterior lumbar fusion.

Abstract: An economic model was developed to compare costs of stand-alone anterior lumbar interbody fusion with recombinant human bone morphogenetic protein 2 on an absorbable collagen sponge versus autogenous iliac crest bone graft in a tapered cylindrical cage or a threaded cortical bone dowel. The economic model was developed from clinical trial data, peer-reviewed literature, and clinical expert opinion. The upfront price of bone morphogenetic protein (3380 dollars) is likely to be offset to a significant extent by reductions in the use of other medical resources, particularly if costs incurred during the 2 year period following the index hospitalization are taken into account.

A prospective randomized comparison of coralline hydroxyapatite with autograft in cervical interbody fusion.

Abstract: Study Design.A prospective randomized trial with independent clinical and radiographic outcome review of patients receiving either hydroxyapatite or tricortical iliac crest graft for cervical interbody fusion was conducted.Objective.To determine whether coralline-derived hydroxyapatite is a suitable

Titanium mesh cages for cervical spine stabilization after corpectomy: a clinical and radiological study

Abstract: Object. Reconstruction after anterior cervical decompression has involved the use of tricortical iliac crest bone or fibular strut grafts, but has been associated with significant morbidity. In this study the authors evaluated the efficacy of titanium mesh cages (TMCs) for stability and fusion following anterior cervical corpectomy. Methods. Thirty-seven patients were prospectively evaluated during a 4-year period. The majority presented with spinal cord compression (97%) often due to cervical spondylosis (87%). The TMC was filled with iliac crest bone chips or Surgibone and stabilized by anterior cervical plates (ACPs). The changes in settling ratio, coronal and sagittal angles, and sagittal displacement were determined at 3, 6, and 12 months; immediate postoperative radiographs were used as baseline. Flexion—extension radiographs and computerized tomography (CT) scans (obtained at 1 year) were examined to assess stability, fusion, and bone growth within the TMC. Complications such as settling, telescopi...

Stability of bone grafting and placement of implants in the severely atrophic maxilla

Abstract: A severely atrophic maxilla can be restored by bone grafts to allow the insertion of implants. We present 30 consecutive patients treated with autogenous inlay and onlay bone grafts from the iliac crest to the floor of the maxillary sinus and the alveolar crest. A total of 200 implants were inserted 4-6 months after bone grafting. A mean vertical increase in bone thickness of 14mm was achieved. After a mean bone loss of 1.3mm during the first year after bone grafting only minimal resorption was observed during the second and third year. Seven implants failed to integrate and a further four implants were lost during follow-up.

Dorsal plating for displaced intra-articular fractures of the distal radius

Abstract: Thirty patients with a mean age of 42 years and a dorsally displaced intra-articular fracture of the distal radius were treated by dorsal plating (Forte, PI and AO T plates). Twenty-eight required autogenous iliac crest bone graft. Mobilisation was started at 1–2 weeks and patients were left free by 6–8 weeks. At a minimum of 6 months (mean 11 months) functional outcomes were excellent or good in 93% according to the Gartland and Werley score and 60% according to Green and O’Briens modified score. The mean time taken to return to work was 10 weeks. At the final follow-up, three patients had intra-articular steps, two of In these high energy injuries in the younger age group there exists no ideal solution. Internal fixation allows more predictable restoration of anatomy and early return to function.

Ex vivo gene therapy in autologous critical-size craniofacial bone regeneration.

Abstract: In therapeutic bone repairs, autologous bone grafts, conventional or vascularized allografts, and biocompatible artificial bone substitutes all have their shortcomings. The bone formed from peptides [recombinant human bone morphogenetic proteins (BMPs)], demineralized bone powder, or a combination of both is small in size. Tissue engineering may be an alternative for cranial bone repair. In this study, the authors developed an animal model to test the hypothesis that replication-defective, adenovirus-mediated human BMP-2 gene transfer to bone marrow stromal cells enhances the autologous bone formation for repairing a critical-size craniofacial defect. The mesenchymal stromal cells of miniature swine were separated from the iliac crest aspirate and expanded in monolayer culture 1 month before implantation. The cultured mesenchymal stromal cells were infected with recombinant, replication-defective human adenovirus BMP-2, 7 days before implantation. Bilateral 2 x 5-cm2 cranial defects were created, leaving no osteogenic periosteum and dura behind. Mesenchymal stromal cells at 5 x 10(7)/ml were mixed with collagen type I to form mesenchymal stromal cell/polymer constructs. Mesenchymal stromal cells used for the control site were infected with adenovirus beta-Gal under the same conditions. After 6 weeks and 3 months, 10 miniature swine were euthanized and the cranium repair was examined. Near-complete repair of the critical-size cranial defect by tissue-engineered mesenchymal stromal cell/collagen type I construct was observed. The new bone formation area (in square centimeters) measured by three-dimensional computed tomography demonstrated that the improvement from 6 weeks to 3 months was significantly greater on the experimental side than on the control side (2.15 cm2 versus 0.54 cm2, p < 0.001) and significantly greater at 3 months than at 6 weeks (2.13 cm2 versus 0.52 cm2, p < 0.001). The difference between the experimental and control groups was significant at 3 months (mean difference, 2.13 cm2; p < 0.001). The maximal compressive strength of the new bone was similar to that of the normal cranial bone when evaluated by biomechanical testing (cranium bone versus tissue-engineered bone, 88.646 +/- 5.121 MPa versus 80.536 +/- 19.302 MPa; p = 0.227). Adenovirus was absent from all constructs by immunochemical staining at 6 weeks and 3 months after implantation. The successful repair of cranial defects in this experiment demonstrates the efficacy of the integration of the autologous stem cell concept, gene medicine, and polymers in producing tissue-engineered bone.

In vivo evaluation of bone marrow stromal-derived osteoblasts-porous calcium phosphate ceramic composites as bone graft substitute for lumbar intervertebral spinal fusion

Abstract: Study design Autogenous bone marrow stromal-derived osteoblasts-porous calcium phosphate ceramic composites were constructed in vitro under cell culture for 48 hours and implanted as a bone graft substitute for lumbar intervertebral spinal fusion in rabbits. Objectives To evaluate the efficacy of autogenous bone marrow stromal-derived osteoblasts-porous calcium phosphate ceramic composites as an alternative to autogenous graft materials in a lumbar interbody spinal fusion model. Summary of background data Bone marrow contains a population of rare progenitor cells capable of differentiating into bone, cartilage, muscle, tendon, and other connective tissues. These cells can be induced and differentiated into osteogenic osteoblasts with addition of osteogenic supplements. Combining bone marrow stromal-derived osteoblasts with porous ceramics gave rise to bone tissue in subcutaneous sites and repaired critical size segmental femoral defects. Little work has been done in the spine to assess fusion rates and associated biomechanical characteristics. Methods Five experimental groups were evaluated: sham operation (Group I); porous calcium phosphate ceramics alone (Group II); autogenous tricortical iliac crest (Group III); bone marrow stromal-derived osteoblasts-calcium phosphate ceramic composites (Group IV); bone marrow stromal-derived osteoblasts-calcium phosphate ceramic composites with rhBMP-2 (Group V). All rabbits were killed 12 weeks after surgery, and the spinal fusion segments underwent the evaluation of gross inspection, manual palpation, radiography, computed tomography, nondestructive biomechanical testing, and histologic analysis. Results Successful spinal fusion was achieved by manual palpation in 100% (6/6) of animals in Group IV and Group V, 66.7% (4/6) in Group III, 50% (3/6) in Group II, and 0% (0/6) in Group I. Radiographic studies showed that minimal disc height loss was observed with ceramic blocks than with autograft. Biomechanical testingconfirmed that spines from Group IV and Group V were statistically significantly stiffer in flexion, extension, left and right bending, and left and right torsion than Group III and Group II. Histologic analysis demonstrated a qualitative increase of bone formation in fusion mass in Group IV and Group V versus all other groups. The size of fusion mass and the stiffness of fusion segments were greatest in Group V. Conclusion The results indicate that bone marrow stromal-derived osteoblasts-calcium phosphate ceramic composites may provide an alternative to autogenous graft materials for lumbar interbody spinal fusion. Adding recombinant human bone morphogenetic protein-2 into the composites may reinforce the biomechanical stiffness for spinal fusion segments. Porous calcium phosphate ceramics alone were not suitable as a bone graft substitute for lumbar interbody spinal fusion.

Biomechanical comparison of expandable cages for vertebral body replacement in the cervical spine.

Abstract: Object Recently, expandable cages for vertebral body replacement in the cervical spine have been developed. The purpose of this study was to compare the biomechanical properties of expandable cages with those of a tricortical iliac crest graft and a nonexpandable cage. Methods Forty human cervical spines (C3–5) were tested in flexion, extension, axial rotation, and lateral bending. First all motion segments were evaluated intact. After corpectomy of C-4 the spines were divided into five groups of eight and the following stabilization techniques were used: 1) autologous iliac crest bone graft; 2) mesh titanium cage; 3) anterior distraction device; 4) Synex-C titanium; and 5) Synex-C PEEK. Additionally, anterior plating and anterior plating plus posterior screw/rod fixation were applied. Stiffness, range of motion, and neutral and elastic zones were determined. In comparison with the intact motion segment all implants significantly increased stiffness in flexion and bending, but decreased stiffness in exten...

Comparison of conventional surgery with motorized trephine in bone harvest from the anterior iliac crest

Abstract: Objective. A prospective study was performed to compare morbidity associated with the harvest of corticocancellous block grafts (CCBG) by conventional surgery and procurement of cancellous cores (CC) by means of a motorized trephine from the anterior ilium. Study Design. Seventy-six patients requiring 30 mL or less of cancellous bone for maxillofacial reconstruction were placed into 2 treatment groups. One group underwent harvest of CCBGs in the traditional open medial approach to the anterior ilium. The second group had CCs harvested through a 0.5- to 1.0-cm incision with a motor-driven trephine. The following parameters were used to evaluate patient morbidity: number of days to unassisted ambulation, length of hospital stay, and pain scores for both the recipient and the donor sites. Results. The mean time to patients' unassisted ambulation following a CCBG was significantly longer (2.8 days) than following CC (0.8 days). The mean length of hospital stay following a CCBG was significantly longer (4.1 days) than following a CC (2.2 days). The mean contemporaneous maxillofacial pain scores following procurement of CCs (day 1: 5.6; day 3: 4.2) and procurement of CCBGs (day 1: 5.8; day 3: 4.5) were not significantly different, whereas the mean hip pain was significantly greater (P

The proximal tibia metaphysis: a reliable donor site for bone grafting?

Abstract: Low complication rates have been reported when cancellous bone is taken from the proximal tibia. The current study was done to determine the volume of cancellous bone that can be harvested from the proximal tibia and to determine the risk for postoperative tibia plateau fracture. The average compressed volume that could be harvested from nine tibiae was 5.4 cc compared with a reported volume of 6.0 cc from the iliac crest. In eight cadavers, the proximal tibia was decancellated in eight tibias. The decancellated and the matching eight contralateral intact tibias were loaded to determine the force required to cause a tibial plateau fracture. The null hypothesis, that there is no difference between the decancellated and the intact tibias, could not be rejected. The current experimental study supports the clinical findings that a sufficient amount of cancellous bone can be harvested from the proximal tibial metaphysis and that the risk of postoperative fracture is not increased. Therefore, the proximal tibia is a reliable cancellous bone graft donor site for clinical practice.

[Complications after harvesting of autologous bone from the ventral and dorsal iliac crest - a prospective, controlled study].

Abstract: INTRODUCTION In a prospective, controlled study, donor site morbidity after bone graft harvesting from the anterior and posterior iliac crest was documented. METHODS In 113 patients, monocortical to tricortical bone grafts were taken from the anterior (n = 73) or dorsal (n = 40) iliac crest. Bone graft size (0.4 - 43 cm 3, median 9.7 cm 3), Operation time (12 - 65 minutes, median 28 minutes), and postoperative donor site were documented. RESULTS Donor site morbidity was higher after harvesting from the ventral than from the dorsal iliac crest: total morbidity 48 vs. 32.5 %, large haematomas 9.6 vs. 7.5 %, moderate haematomas 34.3 vs. 15 %, wound dehiscence 2.7 vs. 0 %. One revision operation was necessary because of a large haematoma at the ventral crest. After harvesting from the ventral iliac crest, there was one fracture ofthe iliac wing and one avulsion fracture of the iliac crest. There were no infections, no injuries of arteries or of the lateral femoral cutaneous nerve and no hemiation. After harvesting from the dorsal iliac crest, there were no major complications. CONCLUSION Bone graft harvesting from the posterior iliac crest should be preferred over harvesting from the anterior iliac crest beeause of the substantially reduced donor site morbidity. Harvesting from the ventral iliac crest should have a clear indication, synthetic bone substitutes should be taken into consideration.

Early loading of endosseous implants in the augmented maxilla: a 1-year prospective study.

Abstract: In 10 patients, 68 endosseous implants were inserted in the augmented edentulous maxilla using a one-stage implant placement technique. Three months before implant insertion, the width and height of the alveolar crest were augmented with autologous bone grafts from the iliac crest. In all cases, the resulting bone volume was sufficient for implant insertion. According to an early loading protocol, the implant-supported overdenture was fabricated 2 months after insertion of the implants. Evaluation was performed according to a standardised protocol immediately and 1 year after fabrication of the prosthetic construction. The protocol included assessment of both clinical (bleeding score, pocket depth, implant mobility) and radiographic (marginal bone level on standardised radiographs) parameters. Three implants in two patients in the upper jaw were lost (survival rate: 95.6%). The peri-implant tissues had a healthy appearance and bone loss was minimal. Overall, the patients were very satisfied with the prosthetic construction. From this preliminary study, it is concluded that in selected cases, early loading of implants may develop into a predictable treatment modality after augmentation of the maxilla.

The effects of BMP-7 in a rat posterolateral intertransverse process fusion model.

Abstract: Summary:The use of autologous bone grafting is an essential component in spine fusion because it is the key factor in achieving long-term stable arthrodesis between spinal motion segments. However, harvesting autologous iliac crest bone graft can be associated with significant morbidity and its supp

Reduction of disc space distraction after anterior lumbar interbody fusion with autologous iliac crest graft.

Abstract: STUDY DESIGN A retrospective review with long-term clinical and radiologic assessment was conducted. OBJECTIVE To assess the severity and reasons for the reduction of disc space distraction after successful autograft fusion of the lumbar spine and its clinical consequences. SUMMARY OF BACKGROUND DATA Anterior lumbar interbody fusion is an established treatment for lumbar disc degeneration. It is not firmly established whether the grafted level narrows after surgery, and if so, what the clinical consequences are. METHODS This study assessed 67 patients who underwent anterior lumbar interbody fusion at L4-L5 with autologous iliac crest graft. The disc space height and angle between L4 and L5 were serially measured. Times until fusion and the presence of symptoms before and after surgery and at the latest follow-up assessment were noted. RESULTS The mean follow-up period was 14 years (range, 2.5-32 years). The fusion rate was 96% (64 of 67 patients), and the mean time to fusion was 9 months. In the group that had successful fusion, there was an initial increase in disc space distraction followed by a reduction in 55 patients (86%). The mean preoperative disc space height was 12.1 mm, which increased immediately after surgery to 16.2 mm, but had been reduced to 12.6 mm at the latest follow-up assessment. The reduction in distraction occurred within the first 3 months after surgery and was correlated with age, but not with recurrence of symptoms, the amount of initial distraction, or the gender of the individual. A similar trend was seen with L4-L5 segmental angulation. CONCLUSIONS Reduction of disc space distraction after anterior lumbar interbody fusion using tricortical iliac crest bone graft is a common finding. Despite this, the fusion rate is high, and there is no association with symptom recurrence.

Sinus augmentation bone grafts for the provision of dental implants: report of clinical outcome.

Abstract: Purpose The aim of this study was to report the outcome of sinus augmentation surgery with autogenous bone grafting in routine dental implant practice. Materials and methods Twenty-seven sinus augmentation procedures were undertaken on 18 consecutive patients (mean age 43.7 years). The mandibular symphysis was used as the donor site for 11 patients. The iliac crest was used as a donor site for 7 bilateral cases. Results Six patients had implants placed at the time of grafting: the other 13 had a mean bone graft consolidation period of 24.7 weeks (range 9 to 39 weeks) before implants were placed. One patient who had a repeat procedure had both immediate and delayed techniques. A total of 79 Branemark System Mk II implants were placed in grafted bone (and 2 Mk IV implants were placed in a patient who had to have a repeat procedure) and proceeded to occlusal loading. After a mean follow-up period of 162 weeks (range 76 to 288 weeks), 16 implants failed to integrate in grafted bone, representing an 80.25% survival rate. Fourteen patients proceeded to the planned prosthesis, 3 patients had a compromised treatment plan, and 1 patient was restored conventionally. This represents 94% of patients who were rehabilitated. Discussion and conclusion The sinus augmentation procedure using autogenous bone grafting can Increase bone volume to allow implant placement where there is insufficient bone. The survival of implants in the grafted bone, as measured by integration and successful loading, was reduced compared to implants placed in normal maxillary bone. Infection during the healing of the grafted site reduces the success of subsequent implant osseointegration.