Autologous Bone Group Research Articles

The Effect of Low-Intensity Pulsed Ultrasound on Bone Regeneration and the Expression of Osterix and Cyclooxygenase-2 during Critical-Size Bone Defect Repair.

Low-intensity pulsed ultrasound (LIPUS) is a form of ultrasound that utilizes low-intensity pulsed waves. Its effect on bones that heal by intramembranous ossification has not been sufficiently investigated. In this study, we examined LIPUS and the autologous bone, to determine their effect on the healing of the critical-size bone defect (CSBD) of the rat calvaria. The bone samples underwent histological, histomorphometric and immunohistochemical analyses. Both LIPUS and autologous bone promoted osteogenesis, leading to almost complete closure of the bone defect. On day 30, the bone volume was the highest in the autologous bone group (20.35%), followed by the LIPUS group (19.12%), and the lowest value was in the control group (5.11%). The autologous bone group exhibited the highest intensities of COX-2 (167.7 ± 1.1) and Osx (177.1 ± 0.9) expression on day 30. In the LIPUS group, the highest intensity of COX-2 expression was found on day 7 (169.7 ±1.6) and day 15 (92.7 ± 2.2), while the highest Osx expression was on day 7 (131.9 ± 0.9). In conclusion, this study suggests that LIPUS could represent a viable alternative to autologous bone grafts in repairing bone defects that are ossified by intramembranous ossification.

3D‐printed degradable hydroxyapatite bioactive ceramics for skull regeneration

AbstractHydroxyapatite (HA) bioceramics have been extensively employed as bone tissue scaffolds owing to their biodegradability and osteoinductivity. In our work, HA, a significant component of natural bone tissue used as the raw material to produce porous scaffolds employing three‐dimensional (3D)‐printing technology. Physical and chemical properties, porosity, and compression resistance of the scaffolds were investigated in vitro. The scaffold was confirmed to have a large number of interconnected pore structures on the surface and inside HA scaffolds showed good cell compatibility and cell adhesion in cell text. To analyze the effect of the scaffold on bone repair and regeneration in vivo, the large‐size defect of beagle skull was repaired with a 3D printing group and an autologous bone group (ABG) for 8 months. Images and histological analysis of the 3D printing group indicated better integration with adjacent tissues. However, there were obvious gaps in the ABG, which indicates weak bone regeneration ability of this group due to unmatched implant dimension. Immunohistochemistry and immunofluorescence results showed that 3D‐printed scaffolds had a highly vascularized structure. This study indicates that 3D‐printed bioceramics scaffolds that are osteoinductivity and biodegradable have great potential in maxillofacial bone regeneration.

Efficacy of Modified Lightbulb Technique by Percutaneous Femoral Neck-Head Fenestration Combined With Compacted Artificial Bone Graft for Treating Precollapse Osteonecrosis of the Femoral Head

BackgroundWhether artificial bone provides comparable outcomes to autogenous bone has not been determined for osteonecrosis of the femoral head (ONFH). This study was conducted to compare the clinical outcomes of autogenous and artificial bone grafting (demineralized bone matrix/calcium sulfate [DBM/CaS]) through a modified lightbulb technique by percutaneous femoral neck-head fenestration for treating precollapse ONFH. MethodsA total of 73 Association Research Circulation Osseous Stage Ⅱ ONFH patients (81 hips) who had a mean follow-up of 61 months (range, 52 to 74) were included in this retrospective study. Among them were 40 hips treated with autogenous bone and 41 hips treated with DBM/CaS grafting through the percutaneous femoral neck-head fenestration. The Harris scores, radiographic progressions, clinical success rates, and survival analyses were analyzed. ResultsAt final follow-up, the mean Harris score was 80 points (range, 63 to 92) in the DBM/CaS group and 76 points (range, 69 to 91) in the autogenous bone group (P = .751). The radiographic progression rate was 29.9% in the DBM/CaS group, without significant difference from the autogenous bone group, which was 37.5% (P = .43). About 73.2% of patients in the DBM/CaS group and 75% in the autologous bone group avoided a total hip arthroplasty (P = .85). Survival analysis for femoral head protection revealed similar outcomes between the 2 groups (P > .05). ConclusionPercutaneous femoral neck-head fenestration combined with artificial bone (DBM/CaS) grafting had comparable clinical outcomes to autologous bone grafting on preventing femoral head collapse and rescuing THA at a mean of 61-month follow-up for treating early ONFH.

Radiological and histochemical study of bone regeneration using the costal cartilage in rats.

The purpose of this study was to conduct basic research on the possibility of using cartilage tissue for hard-tissue reconstruction and to observe morphological changes in the transition of the cartilage to bone. A 4-mm diameter bone defect was created in the right mandibular angle of rats. Cartilage, autologous bone, and artificial bone were grafted into the defect. Computed tomography (CT) was performed to measure the increase in bone volume. Further histological evaluation of the grafted site was performed. At 12 weeks, CT show that bone formation in the costal cartilage group was comparable to that in the autogenous bone group. Histologically, in the artificial bone group, a clear boundary was observed between the existing bone and defect, whereas in the costal cartilage and autologous bone groups, laminar plate bone repair of the defect was observed. The findings in this study suggest that bone reconstruction achieved with cartilage grafting is almost equivalent to that with autogenous bone grafting and that bone reconstruction using cartilage is clinically feasible. In future, if regenerated cartilage is successfully applied clinically, bone reconstruction using regenerated cartilage may be feasible.

Clinical Application of Allograft Bone of Alveolar Cleft Repair.

To investigate the osteogenic effect of allograft bone (BIO-GENE) and autologous iliac crest bone graft in the alveolar cleft repair. A total of 131 patients with congenital unilateral alveolar cleft who consulted in our hospital from January 2016 to May 2021 were selected and divided into 3 groups according to the different bone restoration materials used. Group A totaling 43 cases was the autologous bone group; group B totaling 41 cases was the BIO-GENE group; and group C totaling 47 cases was the BMP-2+BIO-GENE group. The preoperative and postoperative cone beam CT data of the same patient were imported into MIMICS 21.0 in DICOM format. The preoperative cleft volume and newly formed bone volume were calculated by 3-dimensional reconstruction to measure their osteogenic rate. The differences in osteogenesis rates were not statistically significant in the group B compared with the group A, and in the group C compared with the group B ( P >0.05 for both). The differences in osteogenesis rates were statistically significant in the group C compared with the group A ( P =0.003). Comparative studies found the allograft bone with an ideal artificial material to repair alveolar clefts has become possible. Meanwhile, the addition of BMP-2 in the allograft bone significantly increased the osteogenic rate.

Comparison of the outcome of different bone grafts combined with modified core decompression for the treatment of ARCO II stage femoral head necrosis

Treatment of ONFH at an early stage is a challenging issue. The modified minimally invasive core decompression combined with bone graft implantation remains controversial. This study aimed to compare the early-middle outcomes of four groups with different bone grafts. A total of 182 patients (192 hips) with ONFH at the ARCO II stage were randomly divided into four groups. The free fibular graft group (FFG), free vascularized fibular graft group (FVFG), autologous iliac bone group (ABG), and β-tricalcium bioceramics phosphate graft (β-TCPG) group. Each group was treated with the modified minimally invasive core decompression and bone graft implantation. The operation time and blood loss were recorded by the same observer. The clinical outcome was evaluated by the Harris Hip Score and VAS score (before, 14days after surgery, and at the last follow-up). The radiographic progression of ONFH was evaluated at least 36months of follow-up. All cases were successful without any complications after the operation. The patients were followed up for 42 to 48 (44.62 ± 1.81) months. There were statistically significant differences among the four groups in operation time (F value = 1520.67; P < 0.01) and blood loss (F value = 5366.81; P < 0.01). The Harris Hip Score in each group was improved significantly from pre-operation to last follow-up (all P < 0.01). At the last follow-up, the difference in the Harris Hip Score in each group was not statistically significant (F value = 0.54; P = 0.984). The VAS scores in each group were decreased significantly from the pre-operation to14 days after surgery (all P < 0.01). At 14days after surgery, the difference in the VAS score in each group was not statistically significant (F value = 0.64; P = 0.59). At the last follow-up, three hips collapsed on the femoral head in the FFG group, two in the FVFG group, two in the ABG group, and three in the β-TCPG group. The four different bone graft implantation showed satisfactory early-middle outcomes. As compared to other bone grafts, the β-TCP bioceramics graft has the advantages of shorter operation time and lesser blood loss. It may be a choice as a bone graft for the treatment of ONFH at an early stage.

Comparison of nano-hydroxyapatite/polyamide 66 bioactive support and autologous iliac bone in bone grafting and fusion for elderly patients with lumbar tuberculosis

To investigate the safety of nano-hydroxyapatite/polyamide 66 (n-HA/PA66) bioactive support in bone grafting and fusion for elderly patients with lumbar tuberculosis, and to analyze its effectiveness and advantages by comparing with autologous iliac bone grafting. A retrospective analysis was performed on 48 elderly patients with lumbar tuberculosis who met the selection criteria between January 2017 and January 2020. The patients all underwent one-stage posterior pedicle screw internal fixation combined with anterior lesion removal and bone grafting and fusion, of which 23 cases applied n-HA/PA66 bioactive support+allogeneic bone graft (n-HA/PA66 group) and 25 cases applied autologous iliac bone graft (autologous iliac bone group). There was no significant difference between the two groups in gender, age, bone density, disease duration, lesion segment, and preoperative pain visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, and Cobb angle ( P>0.05). The operation time, intraoperative blood loss, and postoperative complications, as well as the VAS score, JOA score, American Spinal Injury Association (ASIA) spinal cord injury grading, Cobb angle, and bone fusion were recorded and compared between the two groups. The operations were completed successfully in both groups. n-HA/PA66 group had significantly less operation time and intraoperative blood loss than the autologous iliac bone group ( P<0.05). All patients were followed up 12-24 months, with an average of 15.7 months. And the difference in follow-up time between the two groups was not significant ( P>0.05). Postoperative complications occurred in 3 cases (13%) in the n-HA/PA66 group and 10 cases (40%) in the autologous iliac group, and the difference in the incidence of complications between the two groups was significant ( χ 2=4.408, P=0.036). The postoperative VAS scores and JOA scores significantly improved when compared with the preoperative scores in both groups ( P<0.05), and the difference was significant ( P<0.05) between 2 weeks after operation and the last follow-up. The difference in VAS score at 2 weeks after operation was significant between the two groups ( P<0.05), and there was no significant difference ( P>0.05) at the other time points. At last follow-up, according to the ASIA grading, the effective improvement rate was 86% (18/21) in the n-HA/PA66 group and 90% (18/20) in the autologous iliac group, with no significant difference ( χ 2=0.176, P=0.675). Imaging review showed that grade Ⅰ bony fusion was obtained in both groups, and the fusion time of bone graft in the n-HA/PA66 group was significantly longer than that in the autologous iliac bone group ( P<0.05). There was no significant difference in the Cobb angle at each time point between the two groups ( P>0.05). No recurrence of tuberculosis, loosening or fracture of the internal fixator, or displacement of the bone graft was observed during follow-up. In elderly patients with lumbar spine tuberculosis, the n-HA/PA66 bioactive support combined with allogeneic bone graft can effectively restore and maintain the fusion segment height and physiological curvature of the lumbar spine, and the fusion rate of bone graft is similar to that of autologous iliac bone, which can achieve better effectiveness.

Reparative effect of super active platelet combined with allogeneic bone for large bone defects.

In clinical practice, autologous bone transplantation is usually used to treat large-scale bone defects. However, autologous bone can cause complications such as secondary injury to patients, the scarcity of autografts. In this study, the study of using super active platelet lysate (sPL) and allogeneic bone to treat the 15mm long bone defect in right radius of rabbits, and provide an experimental basis for the next step of clinical bone defect treatment. The critical-size defect of New Zealand white rabbits was made and divided into three groups: autologous bone group, allogeneic bone group, and sPL group. They were euthanized 1, 2, and 3months after the operation, perform imaging and histological observation on the repair of bone defect area. The results showed that there were varying degrees of new bone in the bone defect. CT data showed that the bone defect repair rate and new bone mass in each group increased month by month (P<.05). Bone tissue (BV) and bone tissue to the total volume (BV/TV, %) in the sPL group > allogeneic bone group, autologous bone group > allogeneic bone group, with statistical significance (P<.05). Compared with the allogeneic bone group, the sPL group can significantly promote the healing of bone defects, enhance the bone density after fracture healing. The repair effect after 3months was similar to that of the autogenous bone group. The use of allogeneic bone and sPL therapy may become part of a comprehensive strategy for tissue engineering to treat bone defects.

Guided bone tissue regeneration using a hollow calcium phosphate based implant in a critical size rabbit radius defect

Long bone fractures are common and sometimes difficult to treat. Autologous bone (AB), bovine bone and calcium phosphates are used to stimulate bone growth with varying results. In the present study, a calcium phosphate cement (CPC) that previously showed promising grafting capabilities was evaluated for the first time in a long bone defect. A radius defect of 20 mm was created in 20 rabbits. The defect was filled by either a hollow CPC implant that had been manufactured as a replica of a rabbit radius through indirect 3D printing, or by particulate AB as control. Defect filling and bone formation was evaluated after 12 weeks by combining micro computed tomography (μCT) and scoring of 3D images, together with histomorphometry and histology. The μCT and histomorphometric evaluations showed a similar amount of filling of the defect (combining graft and bone) between the CPC and AB group, but the scoring of 3D images showed that the filling in the CPC group was significantly larger. Histologically the AB graft could not be distinguished from the new bone. The AB treated defects were found to be composed of more bone than the CPC group, including reorganised cancellous and cortical bone. Both the CPC and AB material was associated with new bone formation, also in the middle of the defect, which could result in closing of the otherwise critically sized gap. This study shows the potential for an indirectly 3D printed implant in guided bone regeneration in critically sized long bone defects.

Prevascularized hydrogels with mature vascular networks promote the regeneration of critical-size calvarial bone defects in vivo.

Adequate vascularization of scaffolds is a prerequisite for successful repair and regeneration of lost and damaged tissues. It has been suggested that the maturity of engineered vascular capillaries, which is largely determined by the presence of functional perivascular mural cells (or pericytes), plays a vital role in maintaining vessel integrity during tissue repair and regeneration. Here, we investigated the role of pericyte-supported-engineered capillaries in regenerating bone in a critical-size rat calvarial defect model. Prior to implantation, human umbilical vein endothelial cells and human bone marrow stromal cells (hBMSCs) were cocultured in a collagen hydrogel to induce endothelial cell morphogenesis into microcapillaries and hBMSC differentiation into pericytes. Upon implantation into the calvarial bone defects (8mm), the prevascularized hydrogels showed better bone formation than either untreated controls or defects treated with autologous bone grafts (positive control). Bone formation parameters such as bone volume, coverage area, and vascularity were significantly better in the prevascularized hydrogel group than in the autologous bone group. Our results demonstrate that tissue constructs engineered with pericyte-supported vascular capillaries may approximate the regenerative capacity of autologous bone, despite the absence of osteoinductive or vasculogenic growth factors.

Clinical study on minimally invasive treatment of femoral head necrosis with two different bone graft materials.

To investigate the clinical efficacy and safety of two different bone graft materials in the minimally invasive treatment of early and middle stage femoral head necrosis. A total of 36 patients (39 hips) with avascular necrosis of the femoral head were divided into autologous iliac bone group (ABG) and bioceramics bone group (BBG). Both groups were treated with minimally invasive thick channel decompression to remove dead bone of femoral head. The ABG was treated with autologous iliac bone graft, and BBG was treated with β-tricalcium phosphate bone graft. The operation time, intra-operative blood loss, haemoglobin, and haematocrit were recorded at three and seven days post-operatively. The clinical efficacy and safety were evaluated by Harris score and imaging examination before, and after treatment and at follow-up stages. The patients were followed up for 24 to 45 (average 29.27 ± 3.56) months. The BBG was significantly better than the ABG in terms of operation time, intra-operative blood loss, haemoglobin, and haematocrit value at three days. Compared with pre-operative, theHarris score of the two groups at 12months after operation was significantly improved. The Harris score and the imaging evaluation of the last follow-up exhibited significantly better outcome in BBG than those of ABG. Bioceramics and autologous iliac bone minimally invasive treatment of early and medium-term femoral head necrosis exhibited satisfactory clinical efficacy in the short and medium-term. The bioceramics graft materials have the advantages of reducing trauma, bleeding, operation time, and quick recovery of post-operative functions.

Subtalar distraction arthrodesis for calcaneal malunion - comparison of structural freeze-dried versus autologous iliac bone graft.

This study aims to analyze the outcomes of subtalar distraction arthrodesis (SDA) for calcaneal malunion using structural freeze-dried iliac allograft (FDIA) compared to using autologous iliac bone (AIB). We retrospectively evaluated 57 consecutive cases (51 patients) of calcaneal malunion between March 2006 and December 2017. All patients were followed for an average of 22.8 months. All cases were treated by SDA using structural FDIA (17 cases, group 1), or AIB (40 cases, group 2). The outcome measures included the American Orthopaedic Foot and Ankle Society ankle-hindfoot (AOFAS) scores, visual analog scale (VAS) pain scores, and radiographic measurements. The mean postoperative 3, 6, and 12 months of AOFAS scores and VAS pain score were significantly better in group 2 than those in group 1 (p < 0.05, for all). There were 3 cases (17.6%) of nonunion in the group 1, whereas the group 2 had 2 cases (5.0%), which did not shown significant difference between two groups (p=0.492). Although the mean pre-, postoperative, and final follow-up radiologic parameters in both groups were similar, (p > 0.05, for all) the difference of talocalcaneal height, talocalcaneal angle, and talar declination angle from postoperative to final follow-up were significantly bigger in the group 1. (p < 0.05, for all). Although union rate was not significantly different between the two groups, we obtained more favorable clinical and radiologic outcomes in the autologous iliac bone group. Using FDIA without any orthobiological agent for SDA, there were significant more loss of radiological parameters due to inferior incorporation and biomechanical properties. When considering the SDA for calcaneal malunion, routine use of FDIA without any orthobiological agents as an interpositional graft for SDA is not recommended.

Cranioplasty Using Polymethylmethacrylate Cement Following Retrosigmoid Craniectomy Decreases the Rate of Cerebrospinal Fluid Leak and Pseudomeningocele.

Cerebrospinal fluid (CSF) leak frequently occurs after retrosigmoid craniectomy. The present study investigated the effects of cranioplasty using polymethylmethacrylate (PMMA) cement to reduce the incidence of CSF leak following retrosigmoid craniectomy as compared with the autologous bone flap combined with titanium plates. Two hundred forty-three patients underwent surgeries via retrosigmoid approach for microvascular decompression or tumor resection. Of these, 107 patients underwent craniotomy, and incomplete cranioplasty was performed with autologous bone flap fixed with titanium plates, while 136 patients underwent craniectomy and complete cranioplasty was performed with PMMA cement. Variables including the incidence of CSF leak, pseudomeningocele formation, wound infection, rejection reaction were compared retrospectively based on the clinical data between the 2 groups. In the autologous bone group, 9 patients had postoperative CSF leaks, and 11 patients had pseudomeningoceles, while 3 CSF leaks and 2 pseudomeningoceles were found in the PMMA group. Statistical analysis showed that PMMA significantly decreased the incidence of postoperative CSF leaks (P = 0.03) and pseudomeningocele formation (P = 0.002). Wound infections were observed in 2 and 1 patients between the autologous bone and PMMA group, respectively, which did not differ significantly (P = 0.58). None of the patients in both groups developed a rejection reaction of artificial materials. Complete cranioplasty with PMMA cement following retrosigmoid craniectomy could decrease the incidence of CSF leak and pseudomeningocele formation as compared with the autologous bone flap combined with titanium plates. Thus, PMMA cement is preferable for bone reconstruction with excellent biocompatibility and without increasing the rate of wound infection.

Buccal fat pad-derived stem cells with anorganic bovine bone mineral scaffold for augmentation of atrophic posterior mandible: An exploratory prospective clinical study.

Application of adipose-derived stem cells originated from buccal fat pad (BFP) can simplify surgical procedures and diminish clinical risks compared to large autograft harvesting. This study sought to evaluate and compare the efficacy of buccal fat pad-derived stem cells (BFPSCs) in combination with anorganic bovine bone mineral (ABBM) for vertical and horizontal augmentation of atrophic posterior mandibles. Fourteen patients with atrophic posterior mandible were elected for this prospective exploratory study. BFP (3-5 mL) was harvested and BFPSCs were isolated and combined with ABBM at 50% ratio. The vertical and horizontal alveolar deficiencies were augmented by 50% mixture of ABBM with either BFPSCs (group 1) or particulated autologous bone (group 2). Titanium mesh was contoured to the desired 3D shape of the alveolar ridge and fixated to the host sites over the graft material of the two groups. At first, the amount of new bone areas was calculated by quantitative analysis of cone beam computed tomography (CBCT) images that were taken 6 months postoperatively according to regenerative techniques (group 1 vs group 2 without considering the type of bone defects). Second, these amounts were calculated in each group based on the type of defects. Quantitative analysis of CBCT images revealed the areas of new bone formation were 169.5 ± 5.90 mm2 and 166.75 ± 10.05 mm2 in groups 1 and 2, respectively. The area of new bone formation for vertical defects were 164.91 ± 3.74 mm2 and 169.36 ± 12.09 mm2 in groups 1 and 2, respectively. The area of new bone formation for horizontal deficiencies were 170.51 ± 4.54 mm2 and 166.98 ± 9.36 mm2 in groups 1 and 2, respectively. There were no statistically significant differences between the two groups in any of the pair-wise comparisons (P > 0.05). The findings of the present study demonstrated lack of difference in bone volume formation between BFPSCs and autologous particulate bone in combination with ABBM. If confirmed by future large-scale clinical trial, BFPSCs may provide an alternative to autogenous bone for reconstruction of alveolar ridge defects.

Restoration of the Fronto-Orbital Buttress with Primary Bone Fragments.

ObjectiveForehead deformities are often caused by lack of treatment or incorrect restoration of the frontal buttress, so the underlying frontal buttress should be restored to its previous position to ensure that the previous forehead contour is restored in cases of complex depressed skull fractures. However, since brain injuries from skull fractures could have fatal consequences, the clinical concern in primary surgery has been to save the patient's life, and cosmetic concerns have always been secondary. We retrospectively reviewed fronto-orbital fracture patients who underwent primary restoration with primary bone fragments or an alloplastic implant and compared the surgical outcomes of autologous bone (group 1) and artificial materials (group 2).MethodsA retrospective review was conducted of 47 patients with fronto-orbital fractures between March 2012 and January 2018. The patients underwent primary reconstruction with primary bone fragments or an alloplastic implant. The surgical results were evaluated by the incidence of infection and cosmetic satisfaction of patients.ResultsInfections occurred in one patient (5%) in group 1 and in two patients (15.3%) in group 2, which was not a statistically significant difference. In contrast, at 6 months after surgery, patient satisfaction showed a statistically significant between-group difference (group 1: 4.32 points, group 2: 3.54 points, p=0.001).ConclusionPrimary reconstruction using fractured bone fragments is an effective and preferable method that could result in better surgical outcomes than restoration using an alloplastic implant.

In vivo evaluation of porous lithium-doped hydroxyapatite scaffolds for the treatment of bone defect.

Hydroxyapatite (HA) possesses similar mineral components to bone and possesses good physicochemical properties. Even though pure HA scaffold is brittle, it is insufficient in promoting vascularization and osteoinductivity. This study was conducted to assess whether lithium (Li) incorporated into HA could improve the scaffolds' inherent shortcomings. In the experiments, Li-hydroxyapatite scaffolds' mechanical strength, biocompatibility, and biodegradability were researched primarily. In vivo studies, the Li hydroxyapatite scaffolds were implanted into an animal model to repair the bone defects. Meanwhile, we also evaluated the expression of angiogenic and osteogenic factors. For comparison, autologous bone, hydroxyapatite, and blank control groups were designed. According to the results, Li incorporated with hydroxyapatite did not significantly change the scaffold's degradation velocity, but it obtained higher compress mechanical strength. After Li was doped, bone regeneration was further enhanced but the angiogenic effect was not improved significantly. The in vivo study, Li-HA scaffolds improved new bone formation with GSK-3𝛽 decreased and 𝛽-catenin increased. In conclusion, doped Li into hydroxyapatite was an alternative strategy for improving hydroxyapatite's mechanical property and promoting the osteogenesis potential. This method is highly recommended for clinical application based on this study alone.

Comparison between autologous bone grafts and acrylic (PMMA) implants – A retrospective analysis of 286 cranioplasty procedures

Decompressive craniectomy (DC) is an accepted surgical technique for reducing life-threatening levels of intracranial pressure. Remodelling the cranial vault following DC can constitute a reconstructive challenge and is known to carry significant morbidity. The aim of our study was to evaluate acrylic versus autologous cranioplasty with regard to specific complication rates. A retrospective analysis was conducted of 286 consecutive adult patients who underwent cranioplasty following supratentorial decompressive craniectomy at our institution between January 2003 and June 2013. The patients were followed based on medical records, operative reports, imaging and outpatient contacts in the postoperative course. A total of 221/286 patients in our series received an autologous bone flap. 65/286 cranioplasty procedures were carried out using acrylic (PMMA) implants to cover uni- or bilateral defects. Within the follow-up period a total of 100 operative revisions were performed. 33.3% patients in the autologous bone group and 40.6% of patients in the acrylic group developed complications requiring surgical attention. The main reason for revision was infection with a total of 37 revisions necessary to treat disturbed wound healing. Postoperative sub- and epidural hematomas requiring revision were more frequent in the acrylic group. Resorption of the autologous bone flap requiring operative revision was seen in 8/222 (3.6%) cases. Other complications included loosening of the implant or dislocation. From our data it can be concluded that cranioplasty procedures using autologous bone-flaps and acrylic implants carry signifikant morbidity, but that both are justifiable techniques for cranioplasty in adult patients.

Therapeutic Efficacy of Cranioplasty After Decompressive Craniectomy for Traumatic Brain Injury: A Retrospective Study

Autologous bone removed at the time of decompressive craniectomy (DC) is always the first choice for cranioplasty. The aim of this study was to evaluate the therapeutic efficacy of cranioplasty after DC by measuring the changes in the Functional Independence Measure (FIM) score, as well as to draw a comparison with the pre-cranioplasty FIM score and to evaluate the differences in the outcomes of cases managed by 2 methods: autologous bone (group I) or titanium mesh (group II). We included 47 patients (36 male and 11 female patients) who underwent unilateral cranioplasty after DC for traumatic brain injury at our institute from 2008 to 2017 in this analytical single-institution retrospective study. The primary binary predictor variable was cranioplasty reconstructive material (autologous bone or mesh). The primary outcome variable of interest was increased, decreased, or unchanged FIM score. The secondary outcome variables included evaluation of immediate complications. The Mann-Whitney U test was used to evaluate differences between scores. Group I (n=26) underwent cranioplasty using autologous bone flap, whereas group II (n=21) underwent cranioplasty using dynamic titanium mesh. Increases in FIM scores on the motor function subscale for group I (P=.01278) and group II (P=.00112) were statistically significant. Increases in FIM scores on the cognition subscale for group I (P=.17384) and group II (P=.9492) were statistically insignificant. Evaluation of the primary outcome variable (ie, increased, decreased, or unchanged FIM scores) and secondary outcome variables (ie, immediate complications) showed a statistically insignificant difference between the 2 groups with respect to improvement (P=.51). This study showed that cranioplasty, irrespective of the reconstructive material, after DC in patients with traumatic brain injury results in a significant functional improvement apart from form and esthetics.

The Fate of Lateral Ridge Augmentation: A Systematic Review and Meta-Analysis.

Owing to volumetric changes after tooth extraction, lateral ridge augmentation has become a common procedure prior or simultaneous to implant placement. Nonetheless, little is known with regard to the dimensional remodeling after healing of these lateral ridge augmentation procedures. Hence, the purpose of this systematic review was to assess the stability of bone grafting material between augmentation procedures and final healing, in terms of resorption rate. An electronic and hand literature search was conducted in several databases, such as the Cochrane Oral Health Group Trials Register, Embase, and Cochrane Central Register of Controlled Trials, up until February 2017. Only randomized controlled trials (RCTs) with a mean follow-up of at least 6 months after implant placement aiming to evaluate the stability of grafting material for lateral ridge augmentation were included and quantitatively analyzed. A total of 35 articles were evaluated; however, only 17 RCTs met the inclusion criteria. A total of 15 studies reported information on bone resorption, leading to a total sample of 304 implants. The estimated overall mean horizontal bone gain at the time of regeneration was 3.71 ± 0.24 mm, with 4.18 ± 0.56 mm for the block graft technique and 3.61 ± 0.27 mm for guided bone regeneration (GBR). The estimated overall net bone gain at final re-evaluation (11.9 ± 7.8) was 2.86 ± 0.23 mm. The estimated mean (± SD) resorption after 6 months was 1.13 ± 0.25 mm, with 0.75 ± 0.59 mm for the block graft technique and 1.22 ± 0.28 mm for GBR. The implant survival rate was 97% to 100%. Regardless of the material used for regeneration, different degrees of graft resorption should be expected. Given the sample of investigations analyzed in this review, block grafts seemed to maintain the volume of the initial augmentation site more than GBR techniques. During the initial stages of healing, the GBR technique experienced more changes compared with block grafts. The resorption of the xenograft group was inferior compared with the combination of xenograft and autologous bone groups. Consequently, overcorrection of the horizontal defects should be performed to compensate for the resorption of the grafting materials.

Effects of a bone graft substitute consisting of porous gradient HA/ZrO2 and gelatin/chitosan slow-release hydrogel containing BMP-2 and BMSCs on lumbar vertebral defect repair in rhesus monkey.

Dense biomaterial plays an important role in bone replacement. However, it fails to induce bone cell migration into graft material. In the present study, a novel bone graft substitute (BGS) consisting of porous gradient hydroxyapatite/zirconia composite (PGHC) and gelatin/chitosan slow-release hydrogel containing bone morphogenetic protein 2 and bone mesenchymal stem cells was designed and prepared to repair lumbar vertebral defects. The morphological characteristics of the BGS evaluated by a scanning electron microscope showed that it had a three-dimensional network structure with uniformly distributed chitosan microspheres on the surfaces of the graft material and the interior of the pores. Then, BGS (Group A), PGHC (Group B), or autologous bone (Group C) was implanted into lumbar vertebral body defects in a total of 24 healthy rhesus monkeys. After 8 and 16weeks, anteroposterior and lateral radiographs of the lumbar spine, microcomputed tomography, histomorphometry, biomechanical testing, and biochemical testing for bone matrix markers, including Type I collagen, osteocalcin, osteopontin, basic fibroblast growth factor, alkaline phosphatase, and vascular endothelial growth factor, were performed to examine the reparative efficacy of the BGS and PGHC. The BGS displayed excellent ability to repair the lumbar vertebral defect in rhesus monkeys. Radiography, microcomputed tomography scanning, and histomorphological characterization showed that the newly formed bone volume in the interior of the pores in the BGS was significantly higher than in the PGHC. The results of biomechanical testing indicated that the vertebral body compression strength of the PGHC implant was lower than the other implants. Reverse-transcription polymerase chain reaction and western blot analyses showed that the expression of bone-related proteins in the BGS implant was significantly higher than in the PGHC implant. The BGS displayed reparative effects similar to autologous bone. Therefore, BGS use in vertebral bone defect repair appears promising.