Bone Chips Research Articles

An ultrasonic osteotomy device enhanced post-osteotomy bone healing beyond that with a conventional rotary device in a rat calvarial model

ObjectiveUltrasonic osteotomy devices (UODs) are reported to have many clinical benefits; for example, they cause little damage to adjacent tissues in oral surgery. However, the difference in the tissue repair process between rotary osteotomy devices (RODs) and UODs is still unclear. This study aimed to compare bone healing after osteotomy with UODs versus RODs in a rat calvarial defect model. MethodsCalvarial bone defects were made in male Wistar rats with a UOD on the right side and an ROD on the left side. Bone and morphological changes were quantitatively evaluated for 4 weeks by micro-CT, light microscopy and electron microscopy. Furthermore, after calvarial bone osteotomy, osteoblastic cells were collected from the bone chips and cultured for 2 weeks, and their proliferation and differentiation activities were analysed. ResultsScanning electron microscopy (SEM) showed that UOD cuts had smoother surfaces than ROD cuts. In HE-stained sections and micro-CT images, the bone wound gap was closed earlier on the UOD side than on the ROD side. Bone thickness, the quantity of newly formed bone, and the number of osteocytes were greater on the UOD side than on the ROD side. Cultured osteoblast-like cells harvested from bone chips cut by the UOD had greater proliferative activity than those harvested from ROD-cut bone chips. ConclusionsThe use of a UOD may assist bone regeneration, presumably because osteoblasts differentiated from mesenchymal cells are activated by ultrasonic microvibration and because UODs cause less damage to the bone than conventional RODs.

A novel drill bit design for reducing bone-chip morphology in orthopaedic bone drilling

Bone drilling is necessary during orthopaedic surgery for internal fixation. The drilling through the bones is the same as the mechanical drilling that uses a surgical twisted drill bit. The design and geometry of drill-bit play a paramount role in producing bone debris of various shapes and sizes. These different bone chips are responsible for chip clogging and chip accumulation at drill sites, leading to a higher temperature, torque, and thrust force. This study compared three hollow drill bits with different diamond grit sizes with a conventional surgical twisted drill bit to observe the chip morphology. It was witnessed that the influence of diamond grit size plays a significant role in producing bone debris. Different sizes of bone chips were stimulated with various drill bits. Similar chip characteristics were observed in all types of bone debris with varying drill bits. The twisted drill bit produces thick spiral-shaped bone debris compared to the hollow drill bit. The fine diamond grits in the drill bit reduce the chip morphology of bone debris during bone drilling. Thus, the diamond-impregnated surgical tool is preferable to drilling burr than a surgical twisted drill bit for surgeons during orthopaedic surgery.

Microdanos ósseos gerados na preparação do sítio de instalação de implantes: uma alternativa para análise ex vivo de diferentes protocolos de velocidade de perfuração

ABSTRACT Objective: The aim of this study was to evaluate bone microdamage in sites prepared for implant placement by using an ex vivo model with three drilling rotation speeds. Methods: Bovine bone ribs were used for the creation of 18 osteotomy sites at different rotation speeds: 1200 rpm, 800 rpm, and 400 rpm. Specimens were stained with xylenol orange and prepared for histological analysis by using fluorescence and polarized light microscopies. Bone microdamage was evaluated by number and based on total bone area, as follows: microfracture density (Fr.D = n/mm2), microcrack morphology (diffuse or linear), and density (Cr.D = n/mm2), and presence of bone chips. To complement the analysis, linear microcracks were assessed by using confocal microscopy for three-dimensional visualization. Results: Bone microdamage on the osteotomy sites included microcracks, diffuse damages, microfracture, and bone chip formation. There was an association between bone microdamage and cancellous bone (p 0.0016), as well as a positive correlation between Fr.D and Cr.D (p 0.05, r 0.54). BM occurrence was not different between the three rotation speeds. In 3D, the height of the microcrack depth was 60.81 µm. Conclusion: Bone microdamage occurs during osteotomy, and the ex vivo model used was effective for the assessment of these biomechanical parameters. In addition, microdamage was not influenced by the drilling rotation speed in this experimental condition.

Modified enzymatic collagen digestion-mediated isolation of osteocytes

This study established a method for isolating large numbers of high-purity osteocytes from high-density bone. Bone fragments derived from mice tibia and femurs were alternately digested with type I collagenase and EDTA nine times, and the digested cells and bone chips (BC) were cultured, digested, and passaged when cells were fully grown. The types of cells obtained were identified by morphology, viable cell counts, alkaline phosphatase staining, and biochemical activity analyses, and specific osteocyte and osteoblast markers were evaluated by quantitative real-time polymerase chain reaction. Our results showed that among the cells obtained from the third digestion (fractions 7–9) of wild mice tibias and femurs and the remaining BCs, 85%–90% of the cells were osteocytes. Moreover, their morphology was approximately one-tenth to one-fifth the size of osteoblasts, star-shaped or polygonal, with a dendritic structure, negative for alkaline phosphatase staining, and showed a high expression of dmp1 and sclerostin. Ninety percent of the cells in fractions 1–3 were osteoblasts, and were fusiform or polygonal shape. The activity of osteoblast-specific alkaline phosphatase and mRNA expression were high in this fraction, while the expression of osteocyte-specific dmp1 and sclerostin was not detected. In the second portion (fractions 4–6), a large number were osteoblasts, mixed with a small number of osteocytes, and had high alkaline phosphatase activity and osteocyte mRNA levels, a specific level of the osteocyte marker dmp1, and no sclerostin was detected. Osteocytes in daβcatot mice were also successfully isolated by this method, and we found that Wnt signaling increased the proliferation of these osteocytes. The proposed method can be used to culture osteocytes and osteoblasts of high purity and can be used for isolation and culture of these two kinds of cells from high-density bone, which provides an avenue for the study of osteocyte function in vitro.

Transfacetal Screw Fixation for Subaxial Cervical Spine.

In the modern era of spine surgery for subaxial cervical spine, transfacetal screw fixation has evolved enormously. Transfacetal screw fixation for subaxial cervical spine is a biomechanically effective technique. In this fixation, four cortical surfaces of the facets are purchased by the transfacetal screws. In this video, we demonstrated the surgical technique of posterior transfacetal screw fixation. Transfacetal screw fixation of subaxial cervical spine was done along with posterior decompression. The entry point of transfacetal screw was defined as 1 mm caudal to mid-point of lateral mass, and screws were directed perpendicular to facet joint in the sagittal plane and straight in the coronal plane. Bone chips were placed over decorticated lateral mass after decompression. Patient had uneventful recovery and maintained good status at follow up. In subaxial cervical spine, transfacetal screw fixation is a biomechanically effective, rigid, and an inexpensive technique to obtain immediate rigid fixation.

Bone chip versus myositis ossificans after supracondylar fracture of humerus.

A 44-year-old male presented to the department of physiotherapy with the primary concern of inability to fully straighten his right elbow. As per the history given by the patient, he had sustained a fall on an outstretched hand 10 months ago. He had sustained a fracture around the elbow, which was managed conservatively with plaster cast for six weeks by a local practitioner. He had pain and swelling around the elbow after the injury, but it had subsided two months ago. On examination, terminal 30 degrees of the range of motion (ROM) of right elbow was limited. Although, forearm supination-pronation was full. The X-ray revealed bone chip at the anterior aspect of the distal humerus, along with supracondylar fracture of the humerus that was not completely healed. Bone chip can be differentiated from myositis ossificans, which is a common complication of fractures around the elbow, by its well-defined margins. As a part of physiotherapy intervention, gentle active ROM of right elbow and functional use of right hand for light activities of daily living was emphasized. The patient was advised to avoid use of heat, massage and jerky movements of elbow as these can lead to myositis ossification. He was assured that he had functional ROM of 30 degrees to 130 degrees elbow flexion, so lack of terminal extension should not bother him in his lifestyle.

Posterior Cervical Decompression and Fusion With Exoscope: 2-Dimensional Operative Video.

Posterior cervical decompression and fusion is an effective strategy for correction of cervical spondylotic myelopathy. Here, we highlight the operative treatment of a 63-yr-old man entailing a 4-level posterior cervical laminectomy and fusion, with the use of an exoscope throughout. The patient initially presented with symptoms of gait dysfunction and loss of fine motor control in the upper extremities, without neck pain or radiculopathy. His imaging demonstrated a congenitally narrowed spinal canal with cervical stenosis at C3-C4, C5-C6, and C6-C7. The patient consented to the procedure and publication of his image, along with other participants and any identifiable individuals. The operation proceeded with the patient in a prone position with midline dissection to the posterior elements of C3-C6. Pilot holes were drilled in the lateral masses and C3-C4, C4-C5, C5-C6, and C6-C7 laminectomies performed using a high-speed drill, with removal of the laminae en bloc. Lateral mass screws were inserted and precontoured rods secured, with morselized autograft and allograft bone chips placed for arthrodesis. Postoperatively, the patient reported noted improvement in his symptoms.

The radiological outcomes of short-segment pedicle screw fixation combined with transforaminal interbody fusion for treatment of thoracolumbar burst fracture

Objective: This study aims to evaluate radiological outcomes of short-segment pedicle screw fixation with transforaminal interbody fusion (TIF) using bone chip graft for treatment of unstable thoracolumbar burst fracture, Denis type IIB. Subject and method: The data in this study were retrospectively collected from all patients with isolated unstable thoracolumbar burst fractures treated by posterior short segment pedicle screw fixation and TIF from January 2013 to January 2017. All patients were followed up for a minimum time interval of 1 year. For radiologic outcome evaluation, a loss percentage of anterior vertebral body heights (%ABC), vertebral kyphotic angle (VKA) and regional kyphotic angle (RKA) were collected preoperatively, postoperatively and at final follow-up. Result: There were 36 patients who met the inclusion criteria with a mean follow-up duration of 53 months (range, 17-73 months). The mean % ABC, VKA and, RKA at the time of admission were 49.9%, 24.6o and 19.7o, respectively. These values were 17.6%, 11.5o, 8.5o postoperatively, and 27.5%, 14.4° and 14.1° at final follow-up, respe­ctively. Fusion rate at final follow-up was 91.7% based on Bridwell’s criteria. There were 6 patients (16.7%) with hardware failure at final follow-up. Conclusion: Short-segment pedicle screw fixation with TIF using bone chip graft is an effective surgical management for unstable thoracolumbar burst fracture with the acceptable radiological outcomes in Vietnamese patients.

Augmentation of Pedicle Screws Using Bone Grafting in Patients with Spinal Osteoporosis.

The aim of the study was to develop a new method of vertebral augmentation based on autologous and allogeneic bone chips to be used in pedicle screw fixation and to compare this method with the technique based on polymethyl methacrylate (PMMA).Materials and MethodsThis prospective non-randomized study included 164 patients with degenerative pathologies or traumatic injuries of the lumbar spine and transitional thoracolumbar segments; 153 of the operated patients were followed up for 18 months. In these patients, radiodensity of the cancellous bone tissue was below 110 HU by the Hounsfield scale. Patients with degenerative spinal disorders underwent pedicle screw fixation using transforaminal interbody fusion; patients with traumatic spinal injuries underwent intermediate pedicle screw fixation, and those with a loss of vertebral body height by >50% underwent anterior fusion.The patients were divided into three groups: in group 1 (n=39), bone tissue augmentation was performed using PMMA; in group 2 (n=21), augmentation was done with bone chips; in group 3 (n=93), no augmentation was performed (control group). The follow-up period was 12 months; cases with fixator breakage or loosening were recorded.ResultsAfter augmentation with PMMA, 11 cases (28.2%) of fixator destabilization were detected. With bone chips, fixator instability developed in 2 patients (9.5%) only, whereas in patients operated without augmentation, the instability was observed in 43 cases (46.2%). With PMMA augmentation, the incidence rate of fixator destabilization did not significantly differ from that in the control group (p=0.0801), while the use of bone chips resulted in a statistically significant decrease of this index compared to the control group (p=0.0023). A logistic regression analysis confirmed the superiority of the developed method over the PMMA-based vertebral augmentation.ConclusionThe use of bone chips for vertebral augmentation provides a statistically significant decrease in the incidence of pedicle screw fixator destabilization in the post-operative period. By reducing the risk of proximal loosening and eliminating the risk of bone cement drainage into the spinal canal and vascular bed, the proposed method may become especially effective in patients with impaired bone density.

Hybrid Bone-Grafting Technique for Staged Revision Anterior Cruciate Ligament Reconstruction.

Hybrid Bone-Grafting Technique for Staged Revision Anterior Cruciate Ligament Reconstruction.

Thermal Effects during Bone Preparation and Insertion of Osseointegrated Transfemoral Implants.

Background: The preparation of bone for the insertion of an osseointegrated transfemoral implant and the insertion process are performed at very low speeds in order to avoid thermal damages to bone tissue which may potentially jeopardize implant stability. The aim of this study was to quantify the temperature increase in the femur at different sites and insertion depths, relative to the final implant position during the stepwise implantation procedure. Methods: The procedure for installation of the osseointegrated implant was performed on 24 femoral specimens. In one specimen of each pair, the surgery was performed at the clinically practiced speed, while the speed was doubled in the contralateral specimen. Six 0.075 mm K fine gauge thermocouples (RS Components, Sorby, UK) were inserted into the specimen at a distance of 0.5 mm from the final implant surface, and six were inserted at a distance of 1.0 mm. Results: Drilling caused a temperature increase of <2.5 °C and was not statistically significantly different for most drill sizes (0.002 < p < 0.845). The mean increase in temperature during thread tapping and implant insertion was <5.0 °C, whereas the speed had an effect on the temperature increase during thread tapping. Conclusions: Drilling is the most time-consuming part of the surgery. Doubling the clinically practiced speed did not generate more heat during this step, suggesting the speed and thus the time- and cost-effectiveness of the procedure could be increased. The frequent withdrawal of the instruments and removal of the bone chips is beneficial to prevent temperature peaks, especially during thread tapping.

Assessment of new method of posterior spinal fusion in the treatment of patients with posttraumatic kyphotic deformity of the thoracic and lumbar spine

Objective. To carry out a comparative analysis of two methods of the posterior bone block formation (with autograft bone chips or with a whole vertebral arch) and to assess the rate of bone block formation, the degree of surgery invasiveness and the patient-reported cosmetic satisfaction with the results.Material and Methods. The study involved 31 patients with kyphotic deformity of the thoracic spine, of which 15 patients underwent spinal fusion using autograft bone chips (control group), and 16 were operated on using a new technique with a whole vertebral arch. The results of treatment were assessed using a modified MacNab scale. During the follow-up period from 1.5 to 2 years, pain syndrome was assessed according to VAS, quality of life according the Oswestry Disability Index, and cosmetic satisfaction was assessed using the SRS-22 scale.Results. In the course of the work, it was revealed that in patients who were operated on using new method, the time of bone block formation according to CT data was shorter, the overall satisfaction with surgery result was higher (mainly due to the absence of a cosmetic defect), and the indicators of the operation duration and blood loss did not differ compared to those in the control group.Conclusion. Based on the results obtained, spinal fusion using a whole vertebral arch can be recommended in clinical practice for surgical interventions in patients with kyphotic deformities of the spine.

New Bone Formation in the Whole Decellularized Cortical Bone Scaffold Using the Model of Revitalizing a Haversian System.

Decellularized allogeneic bone chips act as scaffolds for bone tissue regeneration. Owing to their lack of osteogenic potentials compared to autologous bone graft, decellularized bone scaffolds (DBSs) have applied only to small partial bone defects in clinical settings. Furthermore, only decellularized cancellous bone chips have been limitedly used for the purpose of bone regeneration. The cortical bone has less porosity and less osteogenic materials such as bone morphogenetic proteins in comparison with cancellous bone. In this study, we tried to accelerate new bone formation within the decellularized cortical bone scaffold using a vascular pedicle as an in vivo bioreactor.Forty DBSs were divided into 4 groups with different conditionings (DBS+ demineralized bone matrix [DBM], DBS+DBM+me+mesenchymal stem cells, DBS+DBM+vascular pedicle, and DBS+DBM+vascular pedicle+mesenchymal stem cells) and implanted into the back of 5 rabbits. Half of the DBSs were examined at 8 weeks and the other half at 16 weeks to determine vascularization level and osteogenesis within each group. New bone formation and bone-forming cells related to osteogenesis were observed via histological staining. Inclusion of the vascular pedicle resulted in larger areas of bone regeneration. With time, osteon structures became more prominent in groups containing the vascular pedicle.In summary, vascularized DBSs combined with a vascular pedicle have shown promising results for bone regeneration, thereby representing potential therapeutic alternatives for autologous bone grafts or bone tissue free transfer in large or segmental bone defects. In addition, demineralized whole cortical bone matrix along with vascular pedicle and various bone inductive materials, such as DBM and recombinant human bone morphogenetic protein-2, may be an additional new option of an ideal osteoinductive system.

The first clinical experience of using bone chips to promote sternum reossification after median sternotomy

The OBJECTIVE was to evaluate the first experience of using bone chips in sternum metallic osteosynthesis in terms of safety and clinical efficacy. METHODS AND MATERIALS. 20 patients, 10 people in each group (11 men and 9 women; the average age in Group 1 was 74.2±5.3 years; in Group 2 – (72.4±6.7) years) were enrolled in the study. In accordance with the objective of the study, when suturing the sternum, bone-chip grafts were inserted into the spongy substance in Group 1 patients. Group 2 included patients who underwent surgical treatment according to the generally accepted standard protocol: bone wax was applied to the spongy bone tissue of the sternum. RESULTS. The evaluation of sternum reossification was performed with spiral computed tomography. The initial state of the bone tissue was examined before the operation, in the early postoperative period (12 days) and in the midterm period – 12 months after the operation. The results were evaluated on a point scale: 0 points – sternal diastasis more than 3 mm, 12 points – complete sternal consolidation. In the early postoperative period, the degree of sternum fusion did not differ in both groups. (Group 1 – (3.5±0.7); Group 2 – (3.5±0.8) points). In the mid-term follow-up (12 months after), the degree of sternum fusion in patients of Group 1 was (11±0.7) points, which was almost two times higher than in patients of Group 2 – (5.6±3) points. CONCLUSION. The use of Xeno-materials for bone grafting in patients at high risk of impaired reossification after median sternotomy is safe and effective.

Usage of meat and bone meal in animal, poultry and fish feeds: A survey and risk analysis for the occurrence of bovine spongiform encephalopathy in Bangladesh.

BackgroundBovine spongiform encephalopathy (BSE) is an emerging zoonotic disease of cattle associated with pathological prion protein (PrPsc) transmitted via meat and bone meal (MBM). Although Bangladesh did not experience a BSE outbreak but the country could not export animal products to developed countries as has not yet been declared BSE free country by OIE due to lack of scientific risk evaluation for BSE. The objectives were identification of hazard, release and exposure pathways of pathological prion protein through MBM and analysis of risk for the occurrence of BSE in Bangladesh.MethodsThe scientific data were reviewed, hazards were scheduled and surveys were conducted on livestock production system, import of MBM and its use to identify the hazards present in Bangladesh context. The analysis was done by the ‘OIE Risk Analysis Framework 2006 and European Union (EU) Scientific Steering Committee (SSC) 2003’. From the historical reviews, import of MBM and its use was identified, as external hazards.ResultsThe analysis revealed that these hazards had negligible or moderate risk for the introduction of infectious PrPsc as Bangladeshi cattle are vegetarian cattle. No milk replacer was used and use of slaughtered waste in the animal feed industry is absent. Unconsumable bones are processed to produce bone chips, fertilizers and bone meal for poultry feeds. Scrapie was never prevalent in Bangladesh. Therefore, risk from the internal challenge was negligible in Bangladesh for the occurrence of classical BSE. These prevented the propagation of BSE infectivity and eliminated BSE infectivity from the system very fast, if that was present.ConclusionsIt was concluded that introduction of PrPsc into cattle population of Bangladesh through MBM was very negligible. Therefore, Bangladesh can be considered as BSE negligible risk country.

Osseodensification Versus Subtractive Drilling Techniques in Bone Healing and Implant Osseointegration: Ex Vivo Histomorphologic/Histomorphometric Analysis in a Low-Density Bone Ovine Model.

The aim of this study was to qualitatively and quantitatively assess the effect of osteotomy preparation by conventional, subtractive, or osseodensification instrumentation on osteotomies, treated with or without endosteal implants, and healing capacity. Seven sheep were used, and 56 osteotomies were made in the left and right ilium of the sheep (n = 8/sheep [4 per side/time point (3 and 6 weeks)]). Two different instrumentation techniques were used: (1) conventional/regular drilling in a three-step series of a 2-mm pilot and 3.2-mm and 3.8-mm twist drills and (2) osseodensification drilling with a Densah Bur 2.0-mm pilot and 2.8-mm and 3.8-mm multi-fluted tapered burs. Drilling was performed at 1,100 rpm with saline irrigation. Qualitative histomorphometric evaluation of the osteotomies after 3 and 6 weeks did not indicate any healing impairment due to the instrumentation. In all samples, histologic examination suggested bone remodeling and growth (empty and treated with an implant), irrespective of preparation technique. Osteotomies prepared using the osseodensification instrumentation showed the existence of bone chips autografted into the trabecular spaces along the length of the osteotomy wall. The osseodensification group yielded higher osseointegration rates, as distinguished through qualitative assessment, bone-to-implant contact, and bone-area-fraction occupancy, indicating an increased osteogenic potential in osteotomies prepared using the osseodensification technique.

Customized-3D zirconia barriers for guided bone regeneration (GBR): clinical and histological findings from a proof-of-concept case series

Objectives. The aim of this case series was to evaluate, clinically and histologically, customized-3D zirconia barriers manufactured for guided bone regeneration (GBR) procedures. Methods. Seven healthy consecutive patients with severe bone atrophy (two of them with a bilateral atrophy) were selected for a GBR procedure with a zirconia barrier. In a 3D software (DentalCad, Exocad GmbH, Germany), a virtual bone graft was designed and a shell was designed covering the graft; a standard tessellation language (.STL) file was obtained and milled (M1, Zirkonzahn, Italy) using a 1200 MPa zirconia (Prettau, Zirkonzahn, Italy). Nine GBR surgeries (8 upper-posterior jaw, 1 lower-posterior jaw) were performed using autogenous bone chips mixed with xenograft (SmartBone, IBI-SA, Switzerland / BioOss, Geistlich, Switzerland) covered with a zirconia barrier, fixed by means of screws. After healing, implant sites were prepared with a trephine bur, collecting a bone biopsy, and dental implants were inserted (Neodent, Straumann Group, Switzerland). Specimens were histologically analyzed. Results. Eight successful surgeries were recorded; one zirconia barrier got exposed after one month of healing but no signs of infection were present till the barrier was removed. In all cases it was possible to insert implants with no additional bone augmentation procedures. Histological evaluations showed the presence of intense deposition of new bone. Conclusions. Within the limitations of the present case series, the tested customized-3D zirconia barriers confirmed good clinical and histological performances, and, even in case of premature exposure, did not show signs of infection. Preliminary results suggest they are effective for GBR procedures. Further research is necessary with a larger sample size. Clinical significance. The presented barriers could be a viable alternative to titanium-reinforced polytetrafluoroethylene membranes and customized meshes.

Bilateral Anterior Displaced Sigmoid Sinus in Cochlear Implantation: A Proposed Solution.

To assess the safety, time consumption and presumed postoperative complications of posterior repositioning in cases with bilateral anterior displaced sigmoid sinus (ADSS) having cochlear implant surgery. Cases with bilateral ADSS were included. A cortical bone chip was harvested. Sinus plate was drilled thin and removed, ADSS was repositioned posteriorly and secured by the bone chips. The procedure was completed using the standard posterior tympanotomy (PT) technique. Follow up was done both clinically and by computed tomography (CT). Out of 632 cases operated upon in more than 7years, only 7 cases had Bilateral ADSS (1.1%) of which 5 were females (71.45%). The average age was 8.2 ± 12 (6 children and an adult). No intraoperative bleeding was encountered in any of the 7 cases. The average operative time was 103.6 ± 9.7min. No minor nor major complications were detected in all 7 cases. To keep the advantages of PT, repositioning of ADSS in bilateral cases can be done safely with a reasonable increase in the average operative time.

Addition of autogenous bone chips to deproteinized bovine bone mineral does not have additional benefit in lateral ridge augmentation-A preclinical in vivo experimental study.

To compare the outcome after extensive lateral guided bone regeneration using deproteinized bovine bone mineral (DBBM) with or without autogenous bone chips in a canine model of chronic horizontal alveolar ridge defect. The second, third and fourth lower premolars of both sides were extracted, and the buccal bone walls were completely removed in five beagle dogs. After 4weeks, DBBM particles mixed with autogenous bone chips at a ratio of 1:1 were grafted at one side (DBBM/Auto group), while DBBM particles alone were grafted at the contralateral side (DBBM group). The graft materials on both sides were covered by a resorbable collagen membrane and fixation pins. Microcomputed tomographic volume and histomorphometric analyses were performed at 16weeks post-surgery. The ridges of both groups were recovered horizontally, but new bone formation beyond the original ridge contour at the defect site was not found. The DBBM group exhibited a larger total radiographic augmented volume and new bone volume compared with the DBBM/Auto group, but the differences were minimal (p>.05). Histologically, the regenerated area and new bone area were also slightly larger without any statistical significance in the DBBM group than in the DBBM/Auto group (p>.05). The addition of autogenous bone chips to DBBM for lateral ridge augmentation may confer no advantage over grafting DBBM alone with respect to both space maintenance and de novo bone formation in dogs.

Evaluation of bone grafting for treatment of low-grade chondrosarcoma of long bones

ObjectiveTo retrospectively analyze the biological compatibility and oncologic outcomes of autogenous, allogeneic, or combined bone grafting.MethodsFrom April 2000 to December 2016, 37 patients with histologically confirmed low-grade intramedullary chondrosarcoma of the long bones at Kyungpook National University Hospital were enrolled in this retrospective study. All 37 patients underwent intralesional curettage (with or without cryotherapy) followed by bone grafting. Among the 24 patients who underwent cryotherapy, 13 were treated by prophylactic internal fixation (10 in the femur, 1 in the tibia, and 2 in the humerus). Thirteen patients underwent the same treatment without cryotherapy, whereas 12 did not undergo preventive internal fixation.ResultsA single intraoperative fracture was managed by plate fixation. One patient who underwent cryotherapy and internal fixation developed a fracture distal to the operation site 25 days after surgery, and this fracture was repaired with a long plate. None of the 37 patients showed any recurrence or metastasis.ConclusionsAdequate intralesional curettage (with or without cryosurgery) combined with bone grafting using autogenous and allogeneic bone chips was effective for the treatment of low-grade intramedullary chondrosarcoma. Therefore, prophylactic internal fixation using a plate is recommended in the cryotherapy of definite cortical invasion in weight-bearing bones.