Incomplete Bone Formation Research Articles

Effect of titanium plate fixation on bone healing

Bone formation which is a process before bone remodeling in fracture healing process, was investigated in this study by fixing metallic plate after an artificially created defect in a rabbit femur. Although a complete bone remodeling takes about 6 weeks, present study was conducted by observing the condition of the bone within 3 weeks of healing period. An artificial defect was made in a rabbit femur and Ti-6Al-4V ELI (Ti-64) fixation plate was fixed with two screws on both ends while a defect without fixation was set as the control. After 3 weeks, the femur bone was harvested and evaluated with scanning electron microscopy, Vickers hardness test, and X-ray diffraction analysis. Ti-64 fixation showed rapid bone formation but external callus remaining on the defect area and its surrounding bone area. This bone callus may be replaced with healed bone with the passage of time. On the other hand, control showed incomplete bone formation and bone callus formed in the area without the defect, including further regions from the defect area. This may be affected by irregular load transmission and instability around the bone defect area. We conclude that, Ti-64 fixation shows better bone formation and bone hardness than the control.

Articular cartilage regeneration using acellular bioactive affinity-binding alginate hydrogel: A 6-month study in a mini-pig model of osteochondral defects

BackgroundDespite intensive research, regeneration of articular cartilage largely remains an unresolved medical concern as the clinically available modalities still suffer from long-term inconsistent data, relatively high failure rates and high prices of more promising approaches, such as cell therapy. In the present study, we aimed to evaluate the feasibility and long-term efficacy of a bilayered injectable acellular affinity-binding alginate hydrogel in a large animal model of osteochondral defects. MethodsThe affinity-binding alginate hydrogel is designed for presentation and slow release of chondrogenic and osteogenic inducers (transforming growth factor-β1 and bone morphogenic protein 4, respectively) in two distinct and separate hydrogel layers. The hydrogel was injected into the osteochondral defects created in the femoral medial condyle in mini-pigs, and various outcomes were evaluated after 6 months. ResultsMacroscopical and histological assessment of the defects treated with growth factor affinity-bound hydrogel showed effective reconstruction of articular cartilage layer, with major features of hyaline tissue, such as a glossy surface and cellular organisation, associated with marked deposition of proteoglycans and type II collagen. Microcomputed tomography showed incomplete bone formation in both treatment groups, which was nevertheless augmented by the presence of affinity-bound growth factors. Importantly, the physical nature of the applied hydrogel ensured its shear resistance, seamless integration and topographical matching to the surroundings and opposing articulating surface. ConclusionsThe treatment with acellular injectable growth factor–loaded affinity-binding alginate hydrogel resulted in effective tissue restoration with major hallmarks of hyaline cartilage, shown in large animal model after 6-month follow-up. The translational potential of this articleThis proof-of-concept study in a clinically relevant large animal model showed promising potential of an injectable acellular growth factor–loaded affinity-binding alginate hydrogel for effective repair and regeneration of articular hyaline cartilage, representing a strong candidate for future clinical development.

ID: 1058 Effective bone formation through BMP-2-immobilized highly porous GBR membrane

Sound healing of large bone defects is critical challenges in most of clinical fields. In general healing process of bone regeneration, the rapid infiltration of connective tissue, whereas relatively slow bone regeneration in bone defect leads to the incomplete bone formation. To solve this drawback, guide bone regeneration (GBR) membrane which could prevent rapid infiltration of connective tissue into bone defect, thus GBR membrane is feasible for compact bone regeneration in clinical fields. In recent, the most researchers believed that bioactive molecules-grafted GBR membranes may enhance the bone regeneration. To allow graft of bioactive molecules from porous membrane, chemically modified scaffolds are commonly used. This modification leads to sufficient interaction with active sites of bioactive molecules to stable the immobilization of bioactive molecules in the body. However it is hard to apply to clinical applications because of the toxicity of chemical residue used for the modification. In this study, we developed a GBR membrane with leaf-stacked structure which can allow sustained release of bone morphogenetic protein-2 (BMP-2) without any additional modification. The morphology, mechanical property, BMP-2 release profile, osteogenic differentiation of human periosteum-derived cells, and new bone formation efficiency of the BMP-2-loaded GBR membrane compared with commercial product were investigated.

Case report on managing incomplete bone formation after bilateral sinus augmentation using a palatal approach and a dilating balloon technique

BackgroundPatients with resorbed edentulous alveolar ridges in the posterior maxilla often require lateral window sinus augmentation procedures prior to implant placement. Lateral window sinus augmentation procedures can produce incomplete bone augmentation as consequence of surgical and healing complications producing unusual and complex sinus anatomy. Although incomplete bone formation after sinus augmentation has been described in a previous case reports, this is the first case report that describes grafting these compromised sites prior to implant placement.Case presentationA 65-year-old male patient with no known medical conditions presented with severe chronic localized periodontitis and a combined periodontal-endodontic lesion affecting three first molars. Initial ridge preservation and lateral window sinus augmentation resulted in incomplete bone formation and complex sinus floor anatomy on both right and left sides. A dilating balloon technique on one side and a palatal approach on the other side were utilized for additional sinus augmentation using particulate allograft and resorbable collagen membranes. Healing was uneventful, and implants could be placed and restored at all sites. Periodontal maintenance was conducted every 3 months, and the implants have been in function and periodontally healthy for 2 years.ConclusionDespite initial failure of sinus augmentation to produce suitable implant sites, it is possible to rescue these sites with re-entry grafting procedures and allow successful implant placement and restoration.

Delayed bone healing following high tibial osteotomy related to increased implant stiffness in locked plating

IntroductionAsymmetrical callus formation and incomplete bone formation underneath stiff locking plates have been reported recently in clinical and experimental fracture healing studies. After similar effects were observed in the outcome of high tibial osteotomy (HTO) patients, a retrospective study was performed to quantify the frequency and level of such incomplete healing cases. Material and methodsTwenty-three patients treated with medial open wedge HTO and locking plate (Tomofix™) for posttraumatic or congenital genu varum were investigated. No bone grafts were applied to fill the osteotomy gap. The median correction angle was 8° (5–18°). Elective hardware removal was performed after a median of 19.5 months (12–58 months) following an uneventful clinical course. The most recent postoperative X-ray available (median 21 months; 13–56 months) was evaluated for consolidation of the osteotomy. We performed an in vitro biomechanical experiment using the same HTO on a loaded cadaver knee joint to compare interfragmentary movements (IFMs) when using regular locking screws with the Tomofix™ plate and screws that enabled dynamic stabilisation of this plate. ResultsFifteen patients (65%) displayed incomplete consolidation of the osteotomy underneath the locking plate (10.9% of the osteotomy length) and cortical deficiency. The time to implant removal for these patients of 27 months was longer than the 21 months for the patients with a complete osteotomy gap healing. The biomechanical experiment demonstrated that very low IFMs and corresponding interfragmentary strain occur underneath the plate when using regular locking screws. Replacement with dynamic screws resulted in an increased IFM. Discussion and conclusionsThese results support the hypothesis that low bone formation underneath locking plates is induced by increased stiffness. This high stiffness situation could be altered by replacing the standard screws with dynamic screws which allow for a movement of 0.35mm perpendicular to the screw axis. This resulted in an approximately threefold increase in the IFM and may be a potential concept to avoid incomplete bone healing under stiff plate fixations.

The influence of FDBA and autogenous bone particles on regeneration of calvaria defects in the rabbit: A pilot study

The histological behavior of bone formation using three biomaterials was examined including whether an 8 mm rabbit calvarial defect would behave as a critical size defect. Four trephine defects of 8 mm diameter in were created six rabbit parietal bones. A control defect was maintained only with coagulum and others were filled with autologous bone, FDBA (freeze dried bone allograft) and a mixture of autologous bone with FDBA, respectively. The animals were sacrificed after between 15 and 90 days at intervals of two weeks and the extracted samples were processed for histological evaluation. All control defects showed incomplete bone formation during 90 days of observation. The defects filled with FDBA and mixture of FDBA–autologous bone exhibited a higher regeneration degree than autologous bone after 60 days; however, the only biomaterial revealing complete mineralization of the original defect at 90 days was FDBA. In conclusion, 8 mm defects can be considered as critical size defects and only FDBA showed mature lamellar bone at 90 days.

Incomplete bone formation after sinus augmentation: A case report on radiological findings by computerized tomography at follow-up

PurposeThe aim of this case report is to present a case of incomplete bone formation after sinus augmentation.MethodsA patient having alveolar bone resorption of the maxillary posterior edentulous region and advanced pneumatization of the maxillary sinus was treated with sinus elevation using deproteinized bovine bone in the Department of Periodontology, Kyung Hee University School of Dentistry and re-evaluated with computed tomography (CT) follow-up.ResultsEven though there were no significant findings or abnormal radiolucency on the panoramic radiograph, incomplete bone formation in the central portion of the augmented sinus was found fortuitously in the CT scan. The CT scan revealed peri-implant radiolucency in the apical portion of the implant placed in the augmented maxillary sinus. Nevertheless, the dental implants placed in the grafted sinus still functioned well at over 15 months follow-up.ConclusionsThe result of this case suggests that patients who received maxillary sinus augmentation may experience incomplete bone formation. It is possible that 1) osteoconductive graft material with poor osteogenic potential, 2) overpacking of graft material that restricts the blood supply, and 3) bone microbial contamination may cause the appearance of incomplete bone formation after sinus augmentation. Further studies are needed to elucidate the mechanism of this unexpected result and care must be taken to prevent it.

Expansão Rápida da Maxila Cirurgicamente Assistida. Revisão da Literatura, Técnica Cirúrgica e Relato de Caso

The rapid expansion of the maxilla presents a high index of failure if carry out in patients with increased age, being indicated only to those with incomplete bone formation. The surgical-orthodontic technique makes the correction of maxillary transversal deformities in adult patients possible, with a sufficiently acceptable previsibility and few cases of complications, becoming an excellent choice of treatment for these patients. A literature review and the presentation of a surgical case treated at the Service of Oral and Maxillofacial Surgery at Base Hospital in Bauru, São Paulo, Brazil is demonstrated in this article, with the advantages, surgical indications and technique being argued.

Macroscopical, histological, and morphometric studies of porous bone-replacement materials in minipigs 8 months after implantation

The aim of this investigation was to test the induction of bone formation and biodegradation of different biomaterials based on calcium phosphate (CaP). Up to now, hydroxyapatite and beta-tricalcium phosphate ceramics have routinely been sintered at temperatures of 1300 degrees C. The new CaP biomaterials tested are fabricated by a sol-gel process at only 700 degrees C. Critical-size defects (>5 cm(3)) in the mandible of 15 adult Goettingen minipigs were filled with 1 of the 2 new types of CaP biomaterials, or with 1 of 2 well-known old-type ceramics, or with a gelatin sponge (in the control group). Macroscopical, histological, and morphometric examination of the former defect areas were made 8 months postoperatively. Eight months after implantation of the new CaP biomaterials, complete bone formation was observed in the defect area, and at the same time, the foreign material was resorbed almost completely. After implantation of the classical types of ceramics, only incomplete bone formation and a lesser resorption rate of the foreign bodies were noted. The difference in the bone formation rate was significant: more than 93% for the new CaP biomaterials versus less than 58% for the classical types of ceramics (P < 0.01). The biological behavior of the new CaP biomaterials was better than that of the old-type sintered ceramic bone-grafting materials. These new CaP matrices are suitable for filling bone defects and are of interest for dentists, including implantologists, craniomaxillofacial and orthopedic surgeons, as well as traumatologists.

Comparison of a New Kind of Calcium Phosphate Formula Versus Conventional Calciumphosphate Matrices in Treating Bone Defects – A Long-Term Investigation in Pigs

In clinical practice arises an increasing need for bone substitute materials. The main inorganic part of bone is the hydroxyapatite (HA). A new hydroxyapatite formula was created by a sol-gel-process at low temperature level [4]. The aim of this investigation was to test the biodegradation and the induction of bone formation by this new material and to compare these versus conventional fabricated HA and ß-TCP. 30 one-year-old Goettingen minipigs were divided into five groups. Critical size defect (&gt;5 m3) in the mandible was treated differently in all 5 groups:-group I- filling with pure HA, which was fabricated by sol-gel-technique, group II- control, only gelatinous material was given, group III- conventional ß-TCP [Cerasorb®], in group IV- conventional HA [Endobone®] and in group V [Targobone®], a non denatureted bovine collagen matrix was used. Macroscopical and microscopical investigations of the former defects were made eight months postoperatively. The bone formation was superior in the sol-gel-HA-group (group I) in comparison with the control groups (group II) and the conventional fabricated ceramics groups (III and IV). In the sol-gel-HA group, the biodegradation of this new biomaterial was considered to very good with a resorption rate of more than 98%; eight months postoperatively. In this group complete bone formation was seen in former defects. In the control group, only an incomplete bone formation with 48.4% of the defect area was noted. This difference was significant (p&lt;0,001). A less bone formation was also observed in group III and IV with 57.6% and 56.9%. The bovine non-denaturated collagen matrix (group V) leads to only 20% of new formed bone. The new calcium phosphate formula made by a sol-gel method seems to be superior and suitable for filling bone defects.

Novel calcium phosphate formula for filling bone defects. Initial in vivo long-term results

Up to now hydroxyapatite (HA) and beta-tricalciumphosphate (beta-TCP) ceramics have been routinely sintered at temperatures between 1100 degrees and 1500 degrees C. Our new calcium ceramic is fabricated by a sol-gel process at 200 degrees C. The aim of this investigation was to test the biodegradation of and the induction of bone formation by this material. Eighteen 1-year-old Goettingen minipigs were divided into three groups. Critical size defects (>5 cm(3)) in the mandible were treated differently in all three animals (group 1: filling with 40% beta-TCP plus 60% HA, group 2: pure HA was applied, group 3 served as controls: only gelatinous material was given). Macroscopic and microscopic investigations of the former defects were made 8 months postoperatively. RESULTS. In groups 1 and 2 biodegradation of more than 93% of the new calcium phosphate formula was found 8 months postoperatively and considered to be very good. No difference was observed between pure HA (group 2) and the combination of HA and beta-TCP (group 1). In both groups complete bone formation was seen macroscopically in the former defects. In the control group only incomplete bone formation with 48.4% of the defect area was noted. This difference was significant ( p<0.001). The new calcium phosphate formula made by a sol-gel method at 120 degrees C seems to be suitable for filling bone defects and is of interest for orthopedic surgery, traumatology, craniomaxillofacial surgery, and dentistry.

Maxillary bone growth and implant positioning in a young patient: A case report: Enzo Rossi, Jens O. Andreasen. Int J Periodontics Restorative Dent 2003;23:113-9

The literature supports the efficacy of osseointegrated implants for partially edentulous patients, but care must be exercised in adolescents with incomplete bone formation. Implants do not follow the normal growth of the jaws, and they behave like ankylosed teeth. They may also interfere with the normal growth of the alveolar process and jeopardize the germs of the adjacent permanent teeth or alter eruption. This case report analyzes the unfavorable clinical and radiographic findings of a single-tooth replacement in a young male over a 15-year period. Reprinted with permission of Quintessence Publishing

The lesions of congenital syphilis.

The clinical and radiological presentation of 108 cases of prenatal or congenital syphilis from a ten-year survey are reviewed. Part I deals with 102 cases of early syphilis aged from one day to six months. The bony presentations are reviewed and the relative incidence of the varying appearances stated. Histology was obtained on four cases. This did not show any specific inflammatory change. The changes are thought to be due to growth disturbance, incomplete bone formation and collapse at the growing ends of the bones. In view of the dystrophic origin rather than inflammatory origin, it is suggested that the nomenclature be reviewed. A prospective pathological study is in progress and two further autopsies have shown no inflammatory skeletal lesion. Part II deals with the late inflammatory changes which occurred. These were six cases which consisted of sabre tibiae, arthropathies and gumma. No explanation for the distribution of the lesions can be given.