Augmentation Of Defects Research Articles

Comparison of Autogenous Bone Graft and Endothermic Calcium Phosphate Cement for Defect Augmentation in Tibial Plateau Fractures

Bone graft augmentation is often selected to treat defects associated with unstable tibial plateau fractures. This prospective, randomized, multicenter study was undertaken to determine the efficacy of bioresorbable calcium phosphate cement compared with standard autogenous iliac bone graft in the treatment of these osseous defects. One hundred and twenty acute, closed, unstable tibial plateau fractures (Schatzker types I through VI) in 119 adult patients were prospectively enrolled in twelve study sites in North America between 1999 and 2002. Randomization for the type of grafting of the subarticular defect was done at the time of surgery, with use of a 2:1 ratio, to treatment with calcium phosphate cement (eighty-two fractures) or autogenous iliac bone graft (thirty-eight fractures). After open reduction, standard plate-and-screw or screw-only fixation was used and then either the cement or the bone graft was placed in the defect cavity for subarticular support. Follow-up included standard radiographs, evaluated by multiple reviewers to avoid bias, and knee range-of-motion assessment at six months to one year or later. The age, weight, height, and sex of the patients and the fracture patterns were comparable in the two groups, as were union rates and time to union. There was a significantly (p = 0.009) higher rate of articular subsidence during the three to twelve-month follow-up period in the bone graft group. The bioresorbable calcium phosphate cement used in this study appears to be a better choice, at least in terms of the prevention of subsidence, than autogenous iliac bone graft for the treatment of subarticular defects associated with unstable tibial plateau fractures. Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Comparative in vitro study of the proliferation and growth of ovine osteoblast-like cells on various alloplastic biomaterials manufactured for augmentation and reconstruction of tissue or bone defects

In this in vitro study ovine osteoblast-like cells were cultured on seven different alloplastic biomaterials used for augmentation and for reconstruction of bone defects in dental and craniomaxillofacial surgery. The aim of this study was to examine the growth behaviour (viability, cell density and morphology) of ovine osteoblast-like cells on the investigated biomaterials to get knowledge which biomaterial is qualified to act as a cell carrier system in further in vivo experiments. The biomaterials were either synthetically manufactured or of natural origin. As synthetically manufactured biomaterials Ethisorb, MakroSorb, PalacosR, and PDS film were used. As biomaterials of natural origin BeriplastP, Bio-Oss and Titanmesh were investigated. The cell proliferation and cell colonization were analyzed by a proliferation assay and scanning electron microscopy. Osteoblast-like cells proliferated and attached on all biomaterials, except on Beriplast. On Ethisorb the highest cell proliferation rate was measured followed by PalacosR. Both biomaterials offer suitable growth and proliferation conditions for ovine osteoblast-like cells. The proliferation rates of Bio-Oss, MakroSorb, PDS-film and Titanmesh were low and SEM examinations of these materials showed less spread osteoblast-like cells. The results showed that ovine osteoblast-like cells appear to be sensitive to substrate composition and topography. This in vitro study provides the basis for further in vivo studies using the sheep model to examine the biocompatibility and the long-term interaction between the test material and tissue (bone regeneration).

Alveolar Zygomatic Buttress: A New Donor Site for Limited Preimplant Augmentation Procedures

Augmentation of anterior maxillary alveolar bone defects before placement of endosseous implants still poses a clinical challenge. Previous traumatic loss of upper anterior teeth is often concomitant with significant bone loss. The aim of augmentation is to reconstitute as far as possible the original hard tissue contour. This is a prerequisite for later optimal positioning of the dental implants in accordance with prosthodontic and functional principles. This article describes a new method for the reconstruction of small anterior maxillary alveolar bone defects using donor bone from the zygomatic buttress region. This region provides harvested bone with a natural convex shape, which is ideally suited for the anterior alveolar process region. Later fibrous tissue transplantation to provide more anterior projection to the anterior dental area is also avoided. Bone harvesting was done with the piezoelectric device, which avoids trauma to the mucosal membrane of the maxillary sinus.

Porous Tantalum Patellar Augmentation

Trabecular metal augmentation of bone defects has been associated with favorable bone ingrowth. Animal studies also suggest fibrous tissue attachment to trabecular metal can be achieved. We treated 16 patients with total knee arthroplasty (18 knees) with severe patellar bone loss using trabecular metal patellar reconstruction. The patients were divided into two groups based on the amount of residual patellar bone stock present at the time of surgery: Group 1 (six patients, seven knees) with no patellar bone stock and Group 2 (10 patients, 11 knees) in whom at least 50% of the patellar component surface was covered by host bone. All seven patellar components in Group 1 loosened within 1 year. Two of these developed necrosis of the extensor mechanism leading to extensor mechanism discontinuity. One component in Group 2 became infected and loosened, whereas the remaining 10 components remained stable at minimum 12-month followup. Our results suggest stable fixation of a trabecular metal patellar component can be achieved when residual bone is present for implant fixation, but early loosening is likely to occur when soft tissue is used for fixation to the implant.

Tissue Engineering Solutions for Traumatic Bone Loss

Tissue engineering strategies for the repair, replacement, or augmentation of bone defects involves the use of cells, matrices, and bioregulatory factors. The source (endogenous, exogenous) and character of these factors, however, may vary greatly among the many approaches taken by current investigators. Although the results of current tissue engineering methods for regenerating bone have shown great promise, the extent of damage to extremities associated with war injuries may require the development of techniques that differ substantially from current practice.

The Use of Injectable Collagens for Aesthetic Rejuvenation

Bovine collagen was approved by the Food and Drug Administration in 1982 and since that time has remained a primary filler of choice for soft-tissue augmentation of dermal defects. During the past decade, however, perhaps mirroring the growth and overwhelming acceptance of botulinum toxin for wrinkle reduction, there has been an increase in demand and availability of new injectable filler products. A partial list includes the ever-expanding class of hyaluronans (hyaluronic acids), calcium hydroxylapatite, polymethylmethacrylate, poly-L-lactic acid, and silicone oil. There are many more on the immediate horizon that are under investigation both abroad and in the United States. Nevertheless, the collagen family of agents, regardless of their source of derivation, remain a reliable and useful alternative. They have an unparalleled record of safety and efficacy; they have different formulations, which makes them amenable to many indications and user friendly for the physician. And, for patient, the admixture of local anesthesia reduces the discomfort of the injection procedure.

Reconstruction of femoral defects in revision hip surgery

The use of impaction bone grafting during revision arthroplasty of the hip in the presence of cortical defects has a high risk of post-operative fracture. Our laboratory study addressed the effect of extramedullary augmentation and length of femoral stem on the initial stability of the prosthesis and the risk of fracture. Cortical defects in plastic femora were repaired using either surgical mesh without extramedullary augmentation, mesh with a strut graft or mesh with a plate. After bone impaction, standard or long-stem Exeter prostheses were inserted, which were tested by cyclical loading while measuring defect strain and migration of the stem. Compared with standard stems without extramedullary augmentation, defect strains were 31% lower with longer stems, 43% lower with a plate and 50% lower with a strut graft. Combining extramedullary augmentation with a long stem showed little additional benefit (p = 0.67). The type of repair did not affect the initial stability. Our results support the use of impaction bone grafting and extramedullary augmentation of diaphyseal defects after mesh containment.

Augmentation of Peri-implant Bone Defects with Different Bone Grafts and Guided Bone Regeneration:

Objective; The present investigation was designed to evaluate the regenerating effects of chip bone grafts harvested from implant drilling and biomaterials with or without combined application of guided bone regeneration (GBR) for the augmentation of peri-implant bone defects. Materials and methods; Four mongrel dogs were used. After the mandibular premolars were extracted for 12 weeks, surgical implantation of 4 titanium implants was performed on each side of the mandible. Chip bone was collected during the drilling procedure. Three-wall bone defects, about 2 mm high, 2 mm wide, and 3 mm long, were created at the buccal side of each implant. The osteotomy sites were separately filled with autogenous chip bone, Bio-oss mineral bone or mixture of both except one defect was left empty. The operation areas of the left mandibula were covered with titanium membranes. The right mandibles without membrane were used as controls. The dogs were sacrificed at either 9 or 16 weeks after the second operation. After the specimens containing experimental implants were resected, the resorption amount of the bone graft was measured. Then the specimens were processed for ground sectioning. The sections were stained with methylene blue and alkalescence fuchsin. Histological examination was performed and photographs were taken under photomicroscope. Results; The mean vertical distances of each bone defects were 2.64±0.17 mm in the D1 (control) group, 1.81± 0.21 mm in D2 (autograft) group, 1.72±0.34 mm in D3 (Bio-oss) group, 1.51±0.22 mm in D4 (mixture) group. Statistical analysis demonstrated that there was significant difference between the results of D1 and the results of other three groups (p<0.01). No statistical differences were revealed between autograft group and Bio-oss group, as well as Bio-oss group and mixture group. It is confirmed there was significant difference between autograft group and mixture group (p<0.05). Histological observations revealed both quantity and quality of regenerated bone in the mixture grafted specimens were superior to that of single Bio-oss grafted or single autologous bone grafted specimens.Whether the membranes were utilized or not, vertical distances of the defects were larger at 16 weeks than those at 9 weeks in all the groups. Bone grafts with titanium membranes were subjected to greater resorption than those without membrane coverings at either 9 weeks or 16 weeks. Statistical analysis indicated there were significant differences in the results between the two groups (p<0.01). Conclusions: This investigation demonstrated the utilization of bone chip collected during implant drilling in combination with biomaterial was a feasible methods for repairing the limited bone defect around the implant. Using the mixture of autogenous bone and Bio-oss mineral as grafting material may significantly promote the bone regenerating effects. The functions of titanium membrane need to be further investigated.

Freeze the Fat

Numerous techniques have been described for prolonging the duration of correction in autologous fat transplantation, and both fresh and frozen fat have been used in the augmentation of dermatologic defects. In this side-by-side, blinded comparison study, investigators measured the effectiveness of frozen fat versus fresh fat in aesthetic improvement. Ten patients underwent autologous fat augmentation of the dorsal side of both hands. Fresh fat was implanted in one hand and frozen fat …

A modified method for preparing platelet-rich plasma: An experimental study

In this study, our aim was to prepare low-cost autogenous platelet-rich plasma (PRP) for use in minor bone grafting procedures. This was the preliminary study of an experimental study concerning augmentation of bony defects with a mixture of PRP and beta-tricalcium phosphate. Venous blood was collected from marginal ear veins of New Zealand White rabbits in EDTA (K3) vacutainer tubes. Blood samples were divided into 2 groups, and PRP was prepared through 2 methods, 1 of which is a variant of the other. The 2 PRP preparation methods described in this study were modified from Landesberg et al (J Oral Maxillofac Surg 58:297, 2000) after several trials, because the platelet enrichment percentages we obtained using their method were very low. Complete blood counts of venous blood samples, PRP, and platelet poor plasma (PPP) were made. Statistical analyses were performed using SPSS for Windows (SPSS, Chicago, IL). It took approximately 30 minutes to prepare PRP with both methods. Platelet counts in PRP were increased with respect to venous blood platelet counts. The differences between the experimental groups and genders were evaluated statistically with Mann-Whitney U tests (P < .05). Correlations between the groups and genders were also evaluated (P < .05). It was experimentally shown that PRP with high platelet counts can be prepared using this modified method without the need for costly autotransfusion systems.

Lipotransfer as an adjunct in head and neck reconstruction.

To present our technique of lipotransfer and to evaluate a single center's experience in the use of lipotransfer as an adjunct to head and neck reconstruction. A retrospective review of all patients undergoing lipotransfer over a 5-year period by the senior author was undertaken. A total of 23 patients with a minimum follow-up of 1 year were available for analysis. Patient records were retrospectively reviewed to assess functional (in the case of palate augmentation) and esthetic outcomes. Twenty-three patients undergoing lipotransfer as part of their reconstructive effort included (1) eight patients undergoing temporal fossa augmentation following temporalis muscle flap reconstruction for extirpative skull base surgery, (2) six patients undergoing facial defect augmentation following traumatic atrophy, (3) three patients undergoing palatal augmentation for correction of velopharyngeal insufficiency, and (4) six patients undergoing soft tissue augmentation following flap reconstruction of the face. Twenty of the 23 patients had excellent maintenance of graft volume. An adequately vascularized recipient bed appears to be an important factor in determining ultimate graft survival using our technique. Lipotransfer of the head and neck represents a simple, effective adjunctive technique providing for large amounts of readily available, well-tolerated soft tissue filler material. Patient selection is important, specifically in regard to determining that there is adequate vascularity of the recipient bed.

Transplants from the shoulder-back region

In spacious or multilayered tissue losses and cases of multiple locations of defects, a large amount of tissue with different components such as skin, fatty tissue, and muscle is required for proper reconstruction. A donor area which can meet these demands is the shoulder-back region with the subscapular vessel, which arises from the axillary artery. We report our clinical experience with 12 patients in whom we reconstructed defects with transplants from this region. Our anatomic investigation and measurements provided proof of a constant anatomy of the vessels with a length of the vascular pedicle and a vascular diameter suitable for microvascular anastomosis. Based on our clinical experience, the scapular, parascapular, and latissmus dorsi muscle transplants are very suitable for the reconstruction of very large superficial defects or for the augmentation of multilayered defects of the upper aerodigestive tract. A main advantage of the transplants from the shoulder and back region is the possibility of combining several transplants with a wide variety of tissue combinations with one vascular pedicle for a single-step reconstruction of multiple defects of the oral cavity and the pharynx.

Porous high-density polyethylene implants (Medpor) for nasal dorsum augmentation

Background: As rhinoplasty techniques are refined, the search for a permanent augmentation material continues. Use of autologous material creates a donor site deformity, and the material may be phagocytized over a period of time. Use of alloplastic materials often results in extrusion and infection. Objective: The purpose of this study was to examine the results of nasal augmentation using porous high-density polyethylene implants. Methods: A Medpor porous high-density polyethylene implant is carved to the approximate desired size and contour. A pocket is made in the dorsum, and sometimes over the caudal border of the septum, to accommodate the dimensions of the implant. The implant is fitted, removed, trimmed, and refitted until the precise desired contour and position are attained. The implant is rinsed in antibiotic solution and placed in position. The mucosal surfaces are closed with absorbable sutures. Results: Over the last 12 years, this technique has been used with satisfactory results in more than 30 patients. Two implants were subsequently removed because of partial implant exposure and possible infection. There were no other significant complications. Four typical cases are presented with up to 12 years of follow-up. Conclusions: When substantial strength is needed, porous high-density polyethylene implants may be used for dorsal augmentation or correction of dorsal defects with satisfactory long-term results and limited complications.

FAT TRANSPLANTATION

Fat transplantation has been used by physicians for over 100 years; however, this technique has been refined considerably since the development of liposuction in the late 1970s. Fat transplantation can be used for augmentation of subcutaneous defects throughout the body. It continues to be the safest and most versatile form of soft tissue augmentation.

Use of lyodura for bone augmentation of osseous defects around dental implants.

Lyodura has been used in periodontology and maxillofacial surgery to overcome different clinical conditions. The use of lyodura to induce new bone formation in humans has not been widely reported. The purpose of this article is to describe the use of lyodura as a resorbable barrier to promote bone formation in osseous defects around dental implants. The study group consisted of 22 healthy patients (12 women and 10 men), with a mean age of 32 (range 20 to 45). A total of 44 implants (9 titanium screw-type and 35 hydroxyapatite-coated cylinder implants) were placed. Of these, 27 implants were placed in the maxilla and 17 in the mandible. At 27 extraction sites bony vertical defects were measured on the buccal, lingual, mesial and distal sides of the implant. In the remaining 17 cases, where either immediate or staged implantation was performed, and a dehiscence was present, its vertical length was measured from the alveolar crest. All bony defects were grafted with autogenous bone harvested from the tuberosity. Each site was covered with lyodura. Healing was uneventful; no inflammation, infection, or soft tissue dehiscence was observed. At all extraction sites and in 76% of the dehiscence defects, hard tissue appearing clinically similar to bone completely filled the defect. Of those defects not completely filled, a mean vertical bone increase of 2.5 mm was recorded. A mean vertical bone increase of 2.6 mm was achieved at extraction sites and a mean increase of 2.79 mm was achieved at dehiscence sites. Lyodura can safely and effectively be used for guided bone regeneration at both extraction sites and for dehiscence defects.

Augmentation of facial soft-tissue defects with Alloderm dermal graft.

Numerous materials, both autologous and nonautologous, have been used for augmentation of soft-tissue defects in the facial region. Each has its limitations. There is no ideal material for soft-tissue augmentation. Alloderm dermal graft (LifeCell Corporation, Woodlands, TX) combines the benefits of autografts and allografts. The authors report its use in 11 patients who have soft-tissue defects or scarring on the face. No serious complications such as rejection, mobilization, absorption, dislocation, or extrusion were encountered. The use of Alloderm in these patients minimized two problems: donor site morbidity and lack of adequate tissue for reconstruction. Alloderm is shown to be an excellent augmentation material for soft-tissue defects. The absence of a donor site defect, and adequate tissue for reconstruction are particularly helpful in the pediatric population.

Augmentation of localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants

Purpose: This study evaluated the applicability of intraorally harvested autogenous bone grafts for the augmentation of the narrow maxillary alveolar ridge to enable insertion of implants for single tooth replacement. Materials and Methods: Local defects of the anterior maxilla were reconstructed in 27 patients with autogenous bone grafts from the mandibular symphysis (n = 12), maxillary tuberosity (n = 8), or mandibular retromolar area (n = 7). Three months after grafting, either Brånemark (n = 23) or ITI Bonefit implants (n = 8) were inserted. Results: At the time of implantation, all grafted sites showed sufficient bone volume for insertion of the implants. Twenty-four to 68 months after insertion, all implants were functioning well. Conclusion: Augmentation of local alveolar defects in the maxilla with intraorally harvested autogenous bone grafts appears to be a reliable method to enable implant placement.

Augmentation of localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants

Augmentation of localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants

Bone substitute with osteoinductive biomaterials — Current and future clinical applications

In craniomaxillofacial surgery, possible indications for the use of osteoinductive biomaterials are interposition in intraosseous defects, contour augmentation, and reconstruction of segmental defects. The experimental results in the field of bone morphogenetic protein (BMP) research within the last few years have shown that it is possible to combine osteoinductive proteins with suitable carrier materials to obtain new composite osteoinductive biomaterials. These carrier materials function as slow-delivery systems for BMP. By combination of BMP with different carrier materials such as various types of calcium phosphate ceramics, collagen or inactive collagenous bone matrix, and other organic and inorganic carriers, the biomaterial can be adapted to clinical demands in a wide range. In several experimental animal studies, we investigated nine different calcium phosphate ceramics and inactive rat bone matrix for their use as BMP carrier. All materials tested seem to be suitable carriers for BMP The first clinical applications are discussed.

The contribution of microsurgical reconstruction to craniofacial surgery.

Craniofacial surgery has revolutionized the surgical treatment of congenital anomalies affecting the facial and cranial skeleton. Similar techniques have since been used in the reconstruction of patients with extensive craniofacial injuries and following craniofacial resection of tumors involving the midface. The application of microsurgical free flaps to some of these craniofacial problems is another significant advance. Microsurgical transfer of deepithelialized skin flaps or omentum will allow the augmentation of soft tissue contour defects of the face in patients with hemifacial microsomia and Romberg's progressive facial hemiatrophy. Following craniofacial resection of extensive tumors of the midface, microsurgical free flaps and vascularized bone grafts will provide soft tissue coverage and, occasionally, both bone and soft tissue composite reconstruction of the resultant defect. Finally, intracranial infection, following craniofacial surgery and neurosurgical excision of tumors involving the skull base, may be effectively prevented by separation of the dura from the nasopharynx by microsurgical transfer of free muscle flaps and omentum.