Bilateral Defects Research Articles

In vivo comparison of a granular and putty form of a sintered and a non-sintered silica-enhanced hydroxyapatite bone substitute material.

Improved handling characteristics of bone substitute materials may facilitate surgical handling. However, the respective modifications should not alter the biological activity. For comparison of a granular and a putty form of two silica-enhanced bone substitute materials, in 30 rabbits, bilateral bone defects were created in the femoral condyle and randomly filled with (1) sintered, silica-enhanced (0.8 wt%) hydroxyapatite (ACg, n = 15); (2) ACg plus resorbable polymer (ACp, n = 15); (3) non-sintered silica-enhanced hydroxyapatite (hydroxyapatite/SiO2 ratio:61:39 wt%; NBg, n = 15); and (4) NBg plus matrix of resorbable polymer (NBp, n = 15). After 4, 8, and 12 weeks, respectively, new-formed bone, remaining bone substitute materials, and amount of soft tissue were quantified histomorphometrically. After four weeks, new-formed bone was increased for NBg/NBp in which NBp showed significantly less remaining bone substitute materials when compared to ACg. After two months, the highest amount of new-formed bone and the least remaining bone substitute materials were seen for NBg and NBp. ACp had less remaining bone substitute material when compared to ACg. In addition, amount of soft tissue was significantly enhanced in NBp when compared to ACg and NBg. After 12 weeks, NBp had significantly lower remaining bone substitute material when compared to ACg. Amount of soft tissue was significantly increased in NBp when compared to ACg and NBg. In accordance, based on an early increase of new-formed bone, a lower amount of remaining bone substitute material, and as well as a distinct degradation, superiority of the non-sintered bone substitute material to the sintered bone substitute material was seen. The effect of the resorbable polymer to each bone substitute material can be supposed to be rather marginal.

OSTEOINDUCTIVE POTENTIAL AND BONE HEALING CAPACITY OF NANOCRYSTALLINE HYDROXYAPATITE (nHA)VERSUS BIODENTINE OF SURGICALLY CREATED DEFECTS IN RABBITS’ ALVEOLAR PROCESS (AN ANIMAL STUDY)

Background: Bone defects resulting from trauma, tumor resection, infection, and congenital or acquired deformities remains an important clinical problem. Synthetic nano-crystalline hydroxyapatite, Nano bone, was successfully used in healing of bone defects without revealing negative side effects. Biodentine; a calcium-silicate based material was reported to have osteogenic and angiogenic properties.Objectives: This study aims to investigate the initial osteoinductive potential of Nano Bone and Biodentine on surgically created defects in rabbit’s alveolar process.Methods: 30 adult male rabbits (1-1.5kg) were used in this study. Bilateral bone defects were created in the mandibles of all rabbits, one in each side; the right sides were experimental, and the lefts were kept empty as control. Animals were then divided into two groups (15 rabbits each); Group I (Biodentine): The right-side defects were loaded with Biodentine material. Group II (Nano Bone): Nano Bone was packed in the right-side defects. Five rabbits were euthanized from each group at; 3, 7 and 14 days postoperatively. Bone defects’ specimens were prepared for histological examination by light microscope as well as quantitative analysis of gene expression of collagen1 alpha and Runx-2 by real time PCR.Results: Biodentine had initiated osteogenesis; yet the newly formed bone was apparently of lesser quality than that formed with Nano Bone. Runx- 2 showed significant increase in Nano Bone compared to Biodentine at 1 week, while collagen1 alpha gene expression was significantly increased at all intervals.Conclusion: Both Nano Bone and Biodentine had initiated osteogenesis. Nano bone showed better healing results when compared to Biodentine.

Effect of icariin/attapulgite/collagen type Ⅰ/polycaprolactone composite scaffold in repair of rabbit tibia defect

To investigate the effect of icarin/attapulgite/collagen type Ⅰ/polycaprolactone (ICA/ATP/Col Ⅰ/PCL) composite scaffold in repair of rabbit tibia defect. The ICA/20%ATP/Col Ⅰ/PCL (scaffold 1), ICA/30%ATP/Col Ⅰ/PCL (scaffold 2), 20%ATP/Col Ⅰ/PCL (scaffold 3), and 30%ATP/Col Ⅰ/PCL (scaffold 4) composite scaffolds were constructed by solution casting-particle filtration method. The structure characteristics of the scaffold 2 before and after cross-linking were observed by scanning electron microscopy, and the surface contact angles of the scaffold 2 and the scaffold 4 were used to evaluate the water absorption performance of the material. The in vitro degradation test was used to evaluate the sustained-release effect of the scaffold 2. Thirty male Japanese white rabbits, weighing (2.0±0.1) kg, were randomly divided into groups A, B, C, D, and E, 6 in each group. After making a 1 cm- diameter bilateral tibial defects model, group A was the defect control group without any material implanted. Groups B, C, D, and E were implanted with scaffolds 3, 4, 1, and 2 at the defect sites, respectively. At 4, 8, and 12 weeks after operation, the repairing effects of 4 scaffolds were observed by gross observation, histological observation of HE and Masson staining, and immunohistochemical staining of osteogenic specific transcription factor (runt-related transcription factor 2, RUNX2), osteogenic related transcription factor [Osterix (OSX), Col Ⅰ, osteopontin (OPN)]. Scanning electron microscopy observation showed that the scaffolds were all porous. The structure of the material was loose before and after cross-linking. The surface contact angle showed that the scaffold was hydrophobic, and the scaffold 2 was more hydrophobic than scaffold 4. The sustained-release effect in vitro showed that the drug could be released in a micro and long-term manner. In the animal implantation experiment, the gross observation showed that the defects were significantly smaller in groups D and E than in groups A, B, and C at 4 and 12 weeks after operation. HE and Masson staining showed that the defect of group A was full of connective tissue at 4 weeks after operation, a large number of fibers were seen in groups B and C, and the new bone formation was observed in groups D and E. The increase of new bone was observed in each group at 8 weeks after operation. The defect of group A was still dominated by connective tissue at 12 weeks after operation, and a small amount of new bone tissue was observed in groups B and C, and a large number of new bone tissue was observed in groups D and E, especially in group E, and most of the materials degraded. Immunohistochemical staining showed that the expressions of RUNX2 and OSX in the new tissues of groups D and E were significantly higher than those of the other groups at 4 weeks after operation. The expression of RUNX2 decreased at 8 and 12 weeks after operation. After 8 weeks and 12 weeks, the expressions of Col Ⅰand OPN increased than in 4 weeks. And the expressions of Col Ⅰ and OPN in the new tissues of groups D and E were significantly more than those of the other groups. ICA/ATP/Col I/PCL composite scaffolds have good porosity and biocompatibility, can promote bone formation, and have good bone regeneration and repair effect.

Comparative Volume Analysis of Alveolar Defects by 3D Simulation.

A precise volumetric assessment of maxillary alveolar defects in patients with cleft lip and palate can reduce donor site morbidity or allow accurate preparation of bone substitutes in future applications. However, there is a lack of agreement regarding the optimal volumetric technique to adopt. This study measured the alveolar bone defects by using two cone-beam computed tomography (CBCT)-based surgical simulation methods. Presurgical CBCT scans from 32 patients with unilateral or bilateral clefts undergoing alveolar bone graft surgery were analyzed. Two hands-on CBCT-based volumetric measurement methods were compared: the 3D real-scale printed model-based surgical method and the virtual surgical method. Different densities of CBCT were compared. Intra- and inter-examiner reliability was assessed. For patients with unilateral clefts, the average alveolar defect volumes were 1.09 ± 0.24 and 1.09 ± 0.25 mL (p > 0.05) for 3D printing- and virtual-based models, respectively; for patients with bilateral clefts, they were 2.05 ± 0.22 and 2.02 ± 0.27 mL (p > 0.05), respectively. Bland–Altman analysis revealed that the methods were equivalent for unilateral and bilateral alveolar cleft defect assessment. No significant differences or linear relationships were observed between adjacent different densities of CBCT for model production to obtain the measured volumes. Intra- and inter-examiner reliability was moderate to good (intraclass correlation coefficient (ICC) > 0.6) for all measurements. This study revealed that the volume of unilateral and bilateral alveolar cleft defects can be equally quantified by 3D-printed and virtual surgical simulation methods and provides alveolar defect-specific volumes which can serve as a reference for planning and execution of alveolar bone graft surgery.

55: Bone Regeneration Assessment Through SPECT/CT Imaging in a Mouse Calvarial Defect Model

Introduction The evaluation of novel synthetic bone implants relies mostly on histological examination, but as bone repair takes several weeks, non-invasive imaging techniques have gained interest in the recent past. Ιn the frame of this study, we establish a SPECT/CT imaging protocol for the longitudinal assessment of bone healing of a calvarial mouse defect model using mineralized collagen-based scaffolds. Materials and Methods Two symmetrical calvarial bone defects, 1.5 mm in diameter each, were created in female Swiss mice. Gaps were monitored weekly through SPECT/CT imaging (γ-CUBE, X-CUBE, Molecubes, providing a resolution of 0.6 mm and 0.05 mm, respectively), using [99mTc]-MDP for 5 weeks. Defects created on the left part of the mouse skull were left unfilled (control group), whereas those on the right part were filled with mineralized horse collagen scaffold materials (HA/Coll). Results and Discussion: The monitoring of bone healing was successfully and accurately performed via SPECT/CT imaging. CT imaging showed the actual bone filling process and the formation of new bone tissue, whereas SPECT imaging provided the increased metabolic activity. For the HA/Coll treated defect, a peak in metabolic activity was noted at week 1 post-surgery and the defect was filled by newly developed bone tissue by week 3 post-surgery (Figure 1). In contrast, the metabolic activity at the control defect area was stable but significantly lower and a complete healing was not observed even up to week 5post-surgery. These results show that combined SPECT/CT imaging can provide an accurate tool for bone healing monitoring. CT is a high resolution tool for new bone formation control and SPECT is a high sensitivity tool for early metabolic activity confirmation, also having a high prognostic value for bone healing. Conclusions SPECT revealed the earliest signs of new bone tissue formation due to the increased metabolic activity and CT provided a clear visualization and quantification ability of the healing process over time. This study is part of the EU Horizon 2020 research and innovation VIVOIMAG project under the Marie Skłodowska-Curie grant agreement No 645757. This study was co-supported through the Programme of Industrial Scholarships of Stavros Niarchos Foundation. Figure 1. Indicative axial CT (a), sagittal SPECT/CT (b) and axial SPECT/CT (c) at 3 h [99m]Tc-MDP post-injection (~2 mCi) of a bilateral calvarial mouse defect treated (HA/Coll) and non-treated (control), at week 1 (first row) and at week 3 (second row) post-surgery.

Three-Dimensional Planning and Patient-Specific Drill Guides for Repair of Spondylolysis/L5 Pars Defect

Incomplete ossification of the pars interarticularis will result in a pars defect, a common cause of low back pain in youth and strongly associated with participation in high-impact sports. If left untreated, it can result in spondylolisthesis, causing dynamic canal stenosis, low back pain, and radiculopathy. The treatment of pars defect was first described by Bucks in 1970, who used screws in the lamina placed through an upward and outward direction. However, because of the multiple inclusion and exclusion criteria and narrow margin of error, the Bucks pars repair technique is not commonly performed. A 28-year-old woman had with low back pain that she had been experiencing since mid-adolescence. Computed tomography revealed a bilateral L5 pars defect without spondylolisthesis. Her L5 vertebra was reconstructed virtually. The screw trajectories, a 3-dimensional (3D) model of the vertebra, and a patient-specific drill guide (PSDG) were designed and printed using positioning guide software (MySpine MC Guides [Medacta International SA, Castel San Petro, Switzerland]). A modified Bucks procedure using cannulated compression screws and the PSDG was performed. Follow-up computed tomography revealed accurate placement of the compression screws, mirroring the planned trajectory. The patient was pain free at 3 months postoperatively, and early union across the defect was visualized on the 5-month radiographic imaging study. Using 3D planning software, complex surgical procedures can be planned using the patient's anatomy and computed tomography. With the aid of 3D-printed PSDGs, screw placement in narrow corridors, such as was shown in our case, is safe, efficient, and achievable.

Trypsin Pre-Treatment Combined With Growth Factor Functionalized Self-Assembling Peptide Hydrogel Improves Cartilage Repair in Rabbit Model.

The objective of this study was to improve cartilage repair and integration using self-assembling KLD hydrogel functionalized with platelet-derived growth factor-BB and heparin-binding insulin-like growth factor-1 with associated enzymatic trypsin pre-treatment of the native cartilage. Bilateral osteochondral defects were created at the central portion of the femoral trochlear groove of 48 skeletally mature, white New Zealand rabbits. One limb received a randomly assigned treatment and the contralateral limb served as the control. Treated defects were exposed to trypsin for 2 min and filled with self-assembling KLD hydrogel only, or associated to growth factors. All control limbs received KLD hydrogel alone or received only trypsin but not hydrogel. Ninety days post-defect creation, the rabbits were euthanized and magnetic resonance imaging, radiography, macroscopic evaluation, histology, and immunohistochemistry of the joint and repaired tissue were performed. Mixed model analyses of variance were utilized to assess the outcome parameters and individual comparisons were performed using Least Square Means procedure and differences with p-value < 0.05 were considered significant. Trypsin enzymatic pre-treatment improved cellular morphology, cluster formation and subchondral bone reconstitution. Platelet-derived growth factor-BB improved subchondral bone healing and basal integration. Heparin-binding insulin-like growth factor-1 associated with platelet-derived growth factor improved tissue and cell morphology. The authors conclude that self-assembling KLD hydrogel functionalized with platelet-derived growth factor and heparin-binding insulin-like growth factor-1 with associated enzymatic pre-treatment of the native cartilage with trypsin resulted in an improvement on the cartilage repair process. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2307-2315, 2019.

Repair of skin and soft tissue defects of vulva, vagina, and buttock with internal pudendal artery perforator " angel wing" island flaps in six cases

From November 2015 to July 2017, six patients with skin and soft tissue defects of vulva, vagina, and buttock after resection of vulvar tumors were hospitalized in our unit. All patients were female, aged 45-70 years. Among them, four patients had bilateral defects, and two patients had unilateral defect. The defect area on each side ranged from 6 cm×4 cm to 12 cm×6 cm. Internal pudendal artery perforator " angel wing" island flaps were used to repair and reconstruct the defects. The area of flaps ranged from 7 cm×5 cm to 14 cm×7 cm. The donor sites were sutured directly. All 10 flaps of 6 patients survived. Two patients had local incision infection 3 days after operation. One of the two patients was healed 2 weeks after dressing change, and the other one underwent debridement and suture 1 week after dressing change and was healed 1 week after surgery. Follow-up for 6-12 months after surgery showed no recurrence of tumors, no eversion of vagina, better shape of vulva in bilateral reconstruction cases, and slightly worse symmetry in unilateral reconstruction cases. The skin of the reconstructed area was soft, with sensations of pain, temperature, and touch recovered in varying degrees. The distance of a two-point discrimination was 20-30 mm. Linear scars were left in the flap donor sites, with no impact on squatting or striding. In vaginal examination, 1.5 to 2.0 fingers could be inserted in bilateral reconstruction cases, while 2.0 to 3.0 fingers could be inserted in unilateral reconstruction cases. The anus functioned well during defecation.

The Thin bilateral and bipedicled DIEAP flap for axillary reconstruction in hidradenitis suppurativa.

Reconstruction after resection of advanced stage hidradenitis suppurativa is currently performed with pedicled perforator flaps, that allow functional reconstruction and preservation of shoulder function. Skin availability is limited by the possibility of closing the donor site primarily. Bilateral cases need to be treated in two stages, since the operation is carried out in the lateral decubitus. In this manuscript the application of bilateral and bipedicled DIEAP flaps to bilateral and extensive cases is presented. Between October 2008 and October 2018, 39 patients were treated for axillary hidradenitis suppurativa. Of these, 11 patients had bilateral reconstruction with bilateral DIEAP flaps (22 flaps) and one patient had unilateral reconstruction with a bipedicled DIEAP flap. 23 flaps were used. Twelve flaps were raised above Scarpa's fascia, 6 flaps werethinned after dissection. Three flaps were not thinned in the first stage. Average flap size was 14 × 17cm for the bilateral flaps, while the bipedicled flap was 15 × 32cm. Average operative time was 324 minutes. No flap necrosis was observed. Two patients had wound dehiscences in the axilla and one in the abdomen, all treated conservatively. One patient had a pyoderma gangrenosum at both surgical sites that healed after cortisone therapy. No revisions were needed for the flaps that were thinned during the primary operation. The three patients whose flaps where not thinned needed liposuction after three months for thinning. There was one disease recurrence, unilateral and treated surgically. Mean follow up was 64 months. Axillary reconstruction with the DIEAP flap allows reconstruction of large and bilateral defect in a single operation closing the donor site primarily. If the flap is thinned during the operation, no thinning seems to be needed postoperatively. Otherwise the flap shall be thinned by liposuction three months after the initial procedure. We believe that the benefits of this technique outweigh the added complexity of a microsurgical procedure when bilateral resections are needed, the defects are too wide to close the donor site of a pedicled flap primarily and the lower abdomen is free of disease.

Hyper-Crosslinked Carbohydrate Polymer for Repair of Critical-Sized Bone Defects.

This study evaluated the safety and efficacy of a novel hyper-crosslinked carbohydrate polymer (HCCP) for the repair of critical-sized bone defects in comparison to two alternative treatments: autologous bone and poly(lactide-co-glycolide) with hyaluronic acid (PLGA/HA). Bilateral critical-sized defects were created in the lateral femoral condyles of skeletally mature New Zealand White rabbits, and they were subsequently implanted with HCCP, PLGA/HA, or autologous bone in a randomized manner. Clinical and behavioral observations were made daily, and radiological and histopathological evaluations were performed at 4, 10, and 16 weeks postimplantation. Defects implanted with HCCP showed progressive bone regeneration and bridging of the defect without adverse histological events. No signs of infection or inflammation associated with the implant material were observed in all animals that received HCCP implantation. A radiographic assessment performed at 16 weeks post-implantation showed significantly higher bone density and volume in defects implanted with HCCP compared to PLGA/HA. No statistically significant difference was observed in bone density and volume between HCCP and autologous bone. These findings demonstrate that HCCP is biocompatible, osteoconductive, and capable of promoting bone regeneration in vivo; therefore, it is suitable for both tissue engineering and the repair of critical-sized bone defects.

Design of a Custom-Made Cranial Implant in Patients Suffering from Apert Syndrome

AbstractThis study defines a methodological procedure for the design and manufacturing of a prosthetic implant for the reconstruction of a midsagittal bony-deficiency of the skull due to the Apert congenital disorder. Conventional techniques for craniofacial defects reconstruction rely on the mirrored-image technique. When the cranial lesion extends over the midline or in case of bilateral defects, other approaches based on thin plate spline interpolation or constrained anatomical deformation are applied.The proposed method uses the anthropometric theory of cranial landmarks identification for the retrieval of a template healthy skull, useful as a guide in the successive implant design. Then, anatomical deformation of the region of interest and free-form modelling allow to get the customized shape of the implant. A full bulk and a porous implant have been provided according to the surgeon advises.The models have been 3D printed for a pre-surgical analysis and further treatment plan. They fulfilled the expectancies of the surgeon thus positive results are predictable.This methodology results to be reproducible to any other craniofacial defect spanning over the entire skull.

Evaluation of osseointegration of staged or simultaneously placed dental implants with nanocomposite fibrous scaffolds in rabbit mandibular defect.

Implant-supported dental prosthesis in patients with edentulism or those with reconstructed bone have long survival rate, but the success depends largely on the quality and quantity of the available bone at the recipient site. The usage of autograft is the gold standard treatment for vertical bone augmentation, but it has many limitations. In this study, we have developed a nanocomposite fibrous scaffold [silica coated nanoHA-gelatin reinforced with electrospun poly(L-lactic acid) (PLLA) nanoyarns] and evaluated its efficacy to promote osseointegration in rabbit mandibular defect in comparison to the scaffold without fibers and commercial nanoHA-collagen graft. For this, critical sized bilateral defect (10 mm length, 3 mm depth and 3 mm width) was created in rabbit mandible and dental implantation was done in two manners. In strategy 1, Ti dental implant was placed along with the scaffold and in strategy 2, the scaffold was implanted for 3 months to facilitate new bone formation followed by Ti dental implantation. In strategy 2, the fibrous scaffold could promote new bone formation and osseointegration in rabbit mandibular defect when compared to the scaffolds without fibers and commercial graft, but strategy 1 was not successful. These findings demonstrated that nanocomposite fibrous scaffold is a promising biomaterial to promote new bone formation and osseointegration in mandibular defect.

A patient specific computational biomechanical model for the entire lumbosacral spinal unit with imposed spondylolysis

BackgroundA biomechanical model of the lumbosacral spinal unit between L1-S1 was developed to investigate the behavior of normal and select pathological states. Our aims were to generate predictive structural models for mechanical deformation including critical stresses in the spine components and to investigate the probability of subsequent lumbar spine fractures in the presence of unilateral spondylolysis. MethodsA non-linear three-dimensional finite element pathology-free model of the L1-S1 lumbosacral unit was generated using patient-specific computerized tomography scans and calibrated by comparing it to experimental data of a range of motion modes consisting of flexion, extension, left and right lateral bending, and left and right axial rotation. Unilateral and bilateral pars defects were created on the isthmus of L5 to simulate spondylolysis. FindingsResults showed that under flexion, left lateral bending and right axial rotation, stresses were higher on the contralateral L5 pars-interarticularis, whereas, no significant changes occurred on the left-right isthmus of the L2-L4 and S1. Significant changes in the range of motion compared to the pathology-free model were observed in bilateral spondylolysis not only adjacent to the pars defect area but also in other lumbar spine levels. InterpretationThe proposed pathology-free lumbosacral unit model showed good correlation with experimental tests for all loading cases. In unilateral spondylolysis, a subsequent pars defect was observed within the same vertebra. The overall modeling approach can be used to study different pathological states.

Reconstruction of Bilateral Post-Traumatic Midfacial Defects Assisted by Three-Dimensional Craniomaxillofacial Data in Normal Chinese people—A Preliminary Study

To provide reference data for reconstruction of bilateral midfacial defects for which "mirror technique" cannot be applied. The present study included 4 patients (3 males and 1 female) with post-traumatic bilateral midfacial fractures and defects. The most similar model was retrieved from a database of 552 normal Chinese people and used to guide preoperative virtual surgery planning. All patients underwent open reduction, internal fixation, and reconstruction surgery in 1 stage. A custom-made titanium prosthesis was used to repair the defects of frontal and naso-orbital-ethmoid (NOE) region in 1 patient. Two fibular flaps were used to repair the maxillary defects. A deep circumflex iliac artery flap was used to reconstruct large midfacial defects involving the right zygoma. A surgical navigation system was applied in 3 patients. The 4 patients were followed for 6 to 42months. Two patients had finished all therapies and had satisfactory functional and cosmetic results. The appearance of 1 patient was obviously improved; that patient was still receiving treatment for denture prostheses. One patient had undergone first-stage reconstructive surgery and had normal occlusion at 6months of follow-up. For 3 patients whose treatment had been assisted by navigation, the average surgical deviation was less than 3mm (range, 1.5 to 2.2). For the patient whose treatment had not been assisted with navigation, the deviations differed in different areas: 3.47mm in the right zygomaticomaxillary complex, 5.48mm in the NOE area, and 5.91mm in the maxillary area. For patients with bilateral post-traumatic midfacial defects across the midline, the use of a 3-dimensional craniomaxillofacial database can be considered a feasible method for providing reference data for preoperative planning.

Virtual reconstruction of bilateral midfacial defects by using statistical shape modeling

PurposeMirroring and manual adaptation as the main virtual reconstruction method of midfacial defects is time demanding and ignores asymmetrical skull shapes. By using a statistical shape model (SSM), the reconstruction can be automatized and specified. The current study aims to show the ability of the SSM in the virtual reconstruction of artificial bilateral defects. MethodsBased on 131 pathologically unaffected CT scans of the adult midface region, an SSM was created. DICOM data were generated, segmented and registered on one mesh, which serves as template for the SSM. The SSM consists of the registered surface meshes and includes the shape variability of the cranial vault. Fractured or missing parts were calculated by the known shape variability of healthy midface data. Using 25 CT scans not included in the SSM, the precision of the reconstruction of virtually placed bilateral defects of the orbital floor (Group 1) and bilateral naso-orbital-ethmoid (NOE) fractures (Group 2). Distances to the corresponding parts of the intact skull were calculated to show the accuracy of the virtual reconstruction method. ResultsAll defects could be reconstructed by using the SSM and GM technique. The analysis shows a high accuracy of the SSM-driven reconstruction, with a mean error of 0.75 ± 0.18 mm in group 1 and with a mean error of 0.81 ± 0.23 mm in group 2. ConclusionThe precision of the SSM-driven reconstruction is high and its application is easy for the clinician because of the automatization of the virtual reconstruction process in the field of computer-assisted surgery (CAS). Respecting of the natural asymmetry of the skull and the methods of GM are reasons for the high precision and the automatization of the new shown reconstruction workflow.

State of the Art Simultaneous Bilateral Segmental Mandibular Reconstruction using a Single Fibula Transplant: Discussion of the Surgical Steps

During last 22 years the different reports have shown successful using of vascularized single fibular transplant for a simultaneous bilateral segmental mandibular reconstruction. The surgeries were performed in cases of bilateral mandibular defects of different origin: 1) bilateral infected pseudoarthrosis, 2) bilateral squamous cell carcinoma of the mandible, 3) bilateral ossifying fibroma, 4) osteoradionecrosis that caused mandibular defects, and 5) traumatic mandibular defects. We present a case of a 60-year-old patient who was referred to our clinic with osteoradionecrosis of bilateral mandible, which was reconstructed using a single fibula flap. A 6-month follow-up images are presented.

EVALUATION OF THE RATIONALE OF NEFRECTOMY IN PREGNANT WOMEN WITH PURULENT GESTATIONAL PYELONEPHRITIS

During the last 2 years, an increase in cases of purulent gestational pyelonephritis with severe course and 20 such cases have been revealed and reported. The average age of the patients was 25 years. The first trimester of pregnancy accounted for 10% of cases, the second - 40%; on the third - 50%. In 30% of women there were bilateral defects of kidneys. All patients were operated on. On the first day 12 of them underwent nephrectomy for carbunculosis; 8 women underwent pre-drainage of the urinary tract, which did not improve their condition, and also resulted in nephrectomy. Two patients had to terminate the pregnancy by Caesarean section at a later date, the children were alive; one of these women performed extirpation of the uterus with appendages, the other was subject to supravaginal amputation of the uterus.

Injectable freeze-dried chitosan-platelet-rich-plasma implants improve marrow-stimulated cartilage repair in a chronic-defect rabbit model.

Bone-marrow stimulation (BMS) improves knee-joint function but elicits incomplete repair. Liquid chitosan (CS)-glycerol phosphate/blood clots have been shown to improve BMS-based cartilage repair. Platelet-rich-plasma (PRP)-a rich source of growth factors and cytokines-improves recruitment and chondrogenic potential of subchondral mesenchymal stem cells. We hypothesised that repair response in a rabbit chronic-defect model will improve when freeze-dried CS/PRP is used to augment BMS. Bilateral trochlear defects created in New Zealand white rabbits were allowed to progress to a chronic stage over 4weeks. Chronic defects were debrided and treated by BMS in second surgery, then augmented with PRP (BMS+PRP) or freeze-dried CS/PRP implants (BMS+CS/PRP). The quality of 8-week repair tissue was assessed by macroscopic, histological, and micro computed tomography (Micro-CT) analysis. ICRS macroscopic scores indicated fibrocartilaginous or fibrous repair in control defects that were improved in the BMS+CS/PRP group. An overall improvement in repair in BMS+CS/PRP group was further confirmed by higher O'Driscoll scores, %Saf-O and %Coll-II values. Micro-CT analysis of subchondral bone indicated ongoing remodelling with repair still underway. Quality and quantity of cartilage repair was improved when freeze-dried CS/PRP implants were used to augment BMS in a chronic defect model.

Assessment of Hedgehog Signaling Pathway Activation for Craniofacial Bone Regeneration in a Critical-Sized Rat Mandibular Defect.

Osseous craniofacial defects are currently reconstructed with bone grafting, rigid fixation, free tissue transfer, and/or recombinant human bone morphogenetic protein 2. Although these treatment options often have good outcomes, they are associated with substantial morbidity, and many patients are not candidates for free tissue transfer. To assess whether polysaccharide-based scaffold (PS) constructs that are cross-linked with smoothened agonist (SAG), vascular endothelial growth factor (VEGF), and bone morphogenetic protein 6 (BMP-6) would substantially increase bone regeneration. This animal model study was conducted at the University of Virginia School of Medicine Cui Laboratory from March 1, 2017, to June 30, 2017. Thirty-three 10-week-old female Lewis rats were acquired for the study. Bilateral nonsegmental critical-sized defects were created in the angle of rat mandibles. The defects were either left untreated or filled with 1 of the 9 PSs. The rats were killed after 8 weeks, and bone regeneration was evaluated using microcomputed tomographic imaging and mechanical testing. Analysis of variance testing was used to compare the treatment groups. Blinded analysis and computer analysis of the microcomputed tomographic images were used to assess bone regeneration. In the 33 female Lewis rats, minimal healing was observed in the untreated mandibles. Addition of SAG was associated with increases in bone regeneration and bone density in all treatment groups, and maximum bone healing was seen in the group with BMP-6, VEGF, and SAG cross-linked to PS. For each of the 5 no scaffold group vs BMP-6, VEGF, and SAG cross-linked to PS group comparisons, mean defect bone regeneration was 4.14% (95% CI, 0.94%-7.33%) vs 66.19% (95% CI, 54.47%-77.90%); mean bone volume, 14.52 mm3 (95% CI, 13.07-15.97 mm3) vs 20.87 mm3 (95% CI, 14.73- 27.01 mm3); mean bone surface, 68.97 mm2 (95% CI, 60.08-77.85 mm2) vs 96.77 mm2 (95% CI, 76.11-117.43 mm2); mean ratio of bone volume to total volume, 0.11 (95% CI, 0.10-0.11) vs 0.15 (95% CI, 0.10-0.19); and mean connectivity density 0.03 (95% CI, 0.02-0.05) vs 0.32 (95% CI, 0.25-0.38). On mechanical testing, mandibles with untreated defects broke with less force than control mandibles in which no defect was made, although this force did not reach statistical significance. No significant difference in force to fracture was observed among the treatment groups. In this rat model study, activation of the hedgehog signaling pathway using smoothened agonist was associated with increased craniofacial bone regeneration compared with growth factors alone, including US Food and Drug Administration-approved recombinant human bone morphogenetic protein 2. Pharmaceuticals that target this pathway may offer a new reconstructive option for bony craniofacial defects as well as nonunion and delayed healing fractures. NA.

SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY ASSESSMENT OF FELLOW EYES IN COATS DISEASE.

To assess foveal and parafoveal vasculature at superficial capillary plexus (SCP), deep capillary plexus, and choriocapillaris using optical coherence tomography angiography in the fellow eyes of patients with Coats disease. Observational and prospective case series. Thirteen patients with unilateral Coats and 14 healthy age- and sex-matched controls were consecutively recruited at Manchester Royal Eye Hospital and the Department of Ophthalmology of San Raffaele Hospital. Both groups underwent complete ophthalmologic examination, including optical coherence tomography angiography (Topcon Corp) 3 mm × 3 mm scans. Images were imported into ImageJ software and binarized; foveal avascular zone area was manually outlined and vessel density analyzed in inner (foveal) and outer (parafoveal) areas of SCP, deep capillary plexus, and choriocapillaris. Fellow eyes disclosed a significant increase in the foveal vessel density of SCP (P = 0.04); in particular, superior and temporal quadrants showed more marked alterations (P = 0.02 and 0.04, respectively). Analysis of foveal avascular zone area revealed a significant enlargement in the SCP (P = 0.04). No correlation was found between fellow eyes and the stage of affected eyes. Fellow eyes of Coats patients carry quantitative foveal vascular alterations at SCP. These may represent markers of altered inner blood-retinal barrier, due to a bilateral defect in midcapillary angiogenesis.