Adjacent Bone Research Articles

Humoral immunity at the brain borders in homeostasis.

The meninges encase the brain and spinal cord and house a variety of immune cells, including developing and mature B cells, and antibody-secreting plasma cells. In homeostasis, these cells localize around the dural venous sinuses, providing a defense 'zone' to protect the brain and spinal cord from blood-borne pathogens. Dural plasma cells predominantly secrete IgA antibodies, and some originate from the gastrointestinal tract, with the number and antibody isotype shaped by the gut microbiome. For developing B cells arriving from the adjacent bone marrow, the dura provides a site to tolerize against central nervous system antigens. In this review, we will discuss our current understanding of meningeal humoral immunity in homeostasis.

Neuronal Sprouting and Reorganization in Bone Tissue Infiltrated by Human Breast Cancer Cells.

BackgroundPain is a common complication for patients with metastatic bone disease. Animal models suggest that the pain, in part, is driven by pathological sprouting and reorganization of the nerve fibers innervating the bone. Here, we investigate how these findings translate to humans.MethodsBone biopsies were collected from healthy volunteers (n = 7) and patients with breast cancer and metastatic bone disease (permissions H-15000679, S-20180057 and S-20110112). Cancer-infiltrated biopsies were from patients without recent anticancer treatment (n = 10), patients with recent anticancer treatment (n = 10), and patients with joint replacement surgery (n = 9). Adjacent bone sections were stained for (1) protein gene product 9.5 and CD34, and (2) cytokeratin 7 and 19. Histomorphometry was used to estimate the area of bone marrow and tumor burden. Nerve profiles were counted, and the nerve profile density calculated. The location of each nerve profile within 25 μm of a vascular structure and/or cancer cells was determined.ResultsCancer-infiltrated bone tissue demonstrated a significantly higher nerve profile density compared to healthy bone tissue. The percentage of nerve profiles found close to vascular structures was significantly lower in cancer-infiltrated bone tissue. No difference was found in the percentage of nerve profiles located close to cancer between the subgroups of cancer-infiltrated bone tissue. Interestingly, no correlation was found between nerve profile density and tumor burden.ConclusionsTogether, the increased nerve profile density and the decreased association of nerve profiles to vasculature strongly suggests that neuronal sprouting and reorganization occurs in human cancer-infiltrated bone tissue.

Long term outcomes of en-block autotransplantation of a tooth.

Repositioning of impacted teeth in the dental arch through en-bloc autotransplantation showed short-term efficacy of 89%. The objective of this study was to evaluate the technique for long-term efficacy. The analysis involved 23 teeth transplanted to the alveolar ridge through harvesting the tooth with the adjacent bone tissue. Development of the root was completed and the apical foramen was closed in all the teeth. The teeth were examined clinically and radiologically (CBCT) and compared to contralateral ones. The obtained data were analysed statistically. The efficacy of the procedure amounted to 81% including two teeth lost at an early stage and another two lost during follow-up. The mean age of patients upon performing the procedure was 29.8. The long-term follow-up amounted to the mean of 34.3months. In the study group recession of 1-2mm as well as 3-5mm was found, which was not noted on the control group. In 11.1% of the study group teeth the external root resorption was observed. No transplanted tooth underwent root canal treatment, no periapical changes were observed at CBCT and 77.8% of those showed positive reaction to ethyl chloride. One case of ankylosis was observed in tooth 11 and in two cases increased mobility of the transplanted tooth was found. Regeneration of nerves as well as revascularization in the en-bloc autotransplantation proceeded with high predictability and the risk of ankylosis of the treated tooth seemed to be negligible. Gingival recession was observed more often in case of en-bloc transplantation compared to the control group. The long-term follow-up suggested that this the technique does not prevent external resorption in 100%.

A promising drug combination of mangiferin and glycyrrhizic acid ameliorates disease severity of rheumatoid arthritis by reversing the disturbance of thermogenesis and energy metabolism

BackgroundActivation of immune system in rheumatoid arthritis (RA) consumes amount of energy, and the energy metabolic signals may be a potential target for RA therapy. Baihu-Guizhi decoction (BHGZD) achieves satisfactory therapeutic effects in RA in clinics by recovering the adjacent articular cartilage and bone destruction, and abnormal articular temperature. However, its pharmacological material basis and molecular mechanisms have not been fully elucidated. PurposeThis study focused on exploring the potential acting mechanism of BHGZD against RA, and identifying its main bioactive compounds (BACs) of the combination of mangiferin and glycyrrhizic acid. MethodsKey putative targets of BHGZD acting on adjuvant-induced arthritis (AIA)-M rats were screened by the transcriptomic profiling of the whole blood cells and synovium tissues collected from rats in normal control, AIA-M model and AIA-M-BHGZD treatment groups. Then, BACs of BHGZD against RA were identified using Ultra Performance Liquid Chromatography-Mass spectrum/Mass spectrum, molecular docking, surface plasmon resonance and pharmacokinetic analysis. In vivo experiments based on AIA-M rats and in vitro experiments based on 3T3-L1 preadipocytes were performed to verify the pharmacological effects of BACs against RA and the corresponding mechanisms. ResultsPKA-ADCY5-PPARγ-PGC 1α-UCP1-PRDM16 signal axis was demonstrated to be the candidate targets of BHGZD against RA and was involved in maintaining the balance of thermogenesis and energy metabolism, according to the transcriptional regulatory network analysis based on “herbs-putative targets-disease interaction network”. Then, mangiferin from Rhizoma Anemarrhenae and glycyrrhizic acid from Radix Glycytthizae were identified as the main BACs of BHGZD against RA due to their highly accumulation in the blood in vivo, strong binding affinities with the two candidate targets of BHGZD against RA-ADCY5 and PPARγ, as well as the in vivo and in vitro strong regulation effects on energy metabolism disturbance. ConclusionsThese findings offer evidence that the combination of mangiferin and glycyrrhizic acid from BHGZD may be a promising candidate drug for RA therapy, and also provide an important reference for the development and modernization of traditional Chinese formulae.

Use of the Pixel Value Ratio Following Intramedullary Limb Lengthening: Uncomplicated Full Weight-bearing at Lower Threshold Values.

AimsThe pixel value ratio (PVR) can be used to assess regenerate consolidation after lengthening and guide advice for full weight-bearing (FWB). This study aimed to analyse the PVR in adults having femoral lengthening, the time to FWB and compare findings with the reported values in the literature.Materials and methodsA retrospective database review identified 100 eligible patients who underwent lengthening using the PRECICE nail (68 antegrade and 32 retrograde). The PVR was calculated in each cortex on plain radiographs at every visit. The ratio between the regenerate and an average from the adjacent normal bone was calculated and plotted against the clinical decision to allow FWB.ResultsEighty-seven patients (58 men and 29 women) were assessed; eleven had bilateral lengthening and two patients underwent lengthening twice. The median age was 30.5 years. The underlying cause of shortening was post-traumatic in 46%, with the remaining due to a wide variety of causes, including congenital 16%, syndromic 12% and other causes. The median lengthening achieved was 45 mm, at a median of 57.5 days. The PVR increased with each visit (p <0.0001). FWB was allowed at a median of 42 days after the last day of lengthening, with PVR values of 0.83, 0.84, 0.93 and 0.84 for the anterior, posterior, medial and lateral cortex noted, respectively (average 0.85). There were no implant failures, shortening or regenerate fractures. No differences were detected between antegrade and retrograde nails or with lengthening greater or less than 45 mm. One surgeon allowed earlier FWB at median 31 days with no nail failures.ConclusionPVR is a valuable tool that quantifies regenerate maturity and provides objectivity in deciding when to allow FWB after intramedullary lengthening with the PRECICE nail. FWB was permitted at an earlier time point, corresponding with lower PVR values than have been reported in the literature and with no mechanical failure or regenerate deformation.How to cite this articleElsheikh AA, Wright J, Stoddart MT, et al. Use of the Pixel Value Ratio Following Intramedullary Limb Lengthening: Uncomplicated Full Weight-bearing at Lower Threshold Values. Strategies Trauma Limb Reconstr 2022;17(1):14–18.

Comparing Outcomes of Oligometastases Treated with Hypofractionated Image-Guided Radiotherapy (HIGRT) with a Simultaneous Integrated Boost (SIB) Technique versus Metastasis Alone: A Multi-Institutional Analysis.

Simple SummaryHypofractionated image-guided radiotherapy (HIGRT) is a common method in which high doses of radiation are delivered to treat oligometastatic disease. We have previously reported on the clinical outcomes of treating oligometastases with radiation using an elective simultaneous integrated boost technique (SIB), delivering higher doses to known metastases and reduced doses to adjacent bone or nodal basins. Here we compare outcomes of oligometastases receiving radiation targeting metastases alone (MA) versus those treated via an SIB. Both SIB and MA irradiation of oligometastases achieved high rates of tumor metastases control and similar pain control. Further investigation of this technique with prospective trials is warranted.Purpose: We previously reported on the clinical outcomes of treating oligometastases with radiation using an elective simultaneous integrated boost technique (SIB), delivering higher doses to known metastases and reduced doses to adjacent bone or nodal basins. Here we compare outcomes of oligometastases receiving radiation targeting metastases alone (MA) versus those treated via an SIB. Methods: Oligometastatic patients with ≤5 active metastases treated with either SIB or MA radiation at two institutions from 2013 to 2019 were analyzed retrospectively for treatment-related toxicity, pain control, and recurrence patterns. Tumor metastasis control (TMC) was defined as an absence of progression in the high dose planning target volume (PTV). Marginal recurrence (MR) was defined as recurrence outside the elective PTV but within the adjacent bone or nodal basin. Distant recurrence (DR) was defined as any recurrence that is not within the PTV or surrounding bone or nodal basin. The outcome rates were estimated using the Kaplan–Meier method and compared between the two techniques using the log-rank test. Results: 101 patients were treated via an SIB to 90 sites (58% nodal and 42% osseous) and via MA radiation to 46 sites (22% nodal and 78% osseous). The median follow-up among surviving patients was 24.6 months (range 1.4–71.0). Of the patients treated to MA, the doses ranged from 18 Gy in one fraction (22%) to 50 Gy in 10 fractions (50%). Most patients treated with an SIB received 50 Gy to the treated metastases and 30 Gy to the elective PTV in 10 fractions (88%). No acute grade ≥3 toxicities occurred in either cohort. Late grade ≥3 toxicity occurred in 3 SIB patients (vocal cord paralysis and two vertebral body compression), all related to the high dose PTV and not the elective volume. There was similar crude pain relief between cohorts. The MR-free survival rate at 2 years was 87% (95% CI: 70%, 95%) in the MA group and 98% (95% CI: 87%, 99%) in the SIB group (p = 0.07). The crude TMC was 89% (41/46) in the MA group and 94% (85/90) in the SIB group. There were no significant differences in DR-free survival (65% (95% CI: 55–74%; p = 0.24)), disease-free survival (60% (95% CI: 40–75%; p = 0.40)), or overall survival (88% (95% CI: 73–95%; p = 0.26)), between the MA and SIB cohorts. Conclusion: Both SIB and MA irradiation of oligometastases achieved high rates of TMC and similar pain control, with a trend towards improved MR-free survival for oligometastases treated with an SIB. Further investigation of this technique with prospective trials is warranted.

Atypical multifocal spinal tuberculosis mimicking malignancy on MR imaging

Typical spinal tuberculosis affects the continuous vertebral levels and causes narrowing of the adjacent disc space and bone destruction. However, atypical form of spinal tuberculosis is difficult to distinguish from malignancy, leading to misdiagnosis and delay in treatment. Tuberculous spondylitis is a curable disease if permanent neurologic damage were avoided by early diagnosis and prompt treatment.

Digital Mapping of a Massive Skull-Base Ameloblastoma with Intracranial Extension, Resection, and Reconstruction Using 3D Templates and Molds: Descriptive Case Report and Review

Radical surgery is the mainstay for the treatment of recurrent ameloblastomas; however, it leads to large, complex defects. In this case report, we present an innovative technique of digitally aided resection and reconstruction. A massive histologically confirmed acanthomatous ameloblastoma of the skull-base was digitally mapped with the help of three-dimensional (3D) computed tomography and a custom resection template was fabricated. Digital resection of the skull-base tumor with intracranial extension was done virtually and the resultant defect was reconstructed to create an anatomical replica of the contralateral unaffected side. The tumor was successfully resected with adequate margins guided by the resection template to avoid injury to adjacent vital structures. Subsequent reconstruction was performed by first adapting polymethyl methacrylate bone cement into a series of custom-made 3D molds. Once set, this bone cement served as a reconstructive implant to bridge the ablative defect. The implant offered a precise fit and was secured to healthy adjacent bone using titanium microplates. We present a 6-month follow-up of the case with satisfactory aesthetic results. 3D printing technology has the potential to revolutionize the arena of craniofacial resection with excellent cosmesis and no donor site morbidity if applied appropriately as described here.

Optimizing Newborn Primate Endocast Reconstruction in 3DSlicer

Natural and artificial endocasts have been used for decades to enable researchers to visualize the endocranial space and approximate the morphology of internal soft tissue structures. Producing an endocast of the newborn primate skull is made difficult by the large fontanelle spaces between growing bones. As there is no definitive endocranial boundary, these spaces have the potential to introduce error into both manual and semi‐automatic methods of endocast reconstruction.This study examines three methods of capturing endocranial volume (EV) from the endocasts of multiple species of newborn primates. For each specimen an EV was produced using three methods: a) manual, b) semi‐automatic and c) “patched” semi‐automatic segmentation. Manual segmentation is considered the “gold standard” of endocast reconstruction, however it lacks the efficiency of semi‐automatic methods. The “patched” method proposed here is a novel approach to fontanelle closure that is accomplished using the “Baffle Planner” module in 3DSlicer, an open‐access post‐processing software that is freely accessible to all researchers. The interosseous patches constructed from user‐defined landmarks are placed around the ossifying edges of the fontanelle and reflect the curvature of adjacent bones.In this study we provide guidance for optimizing the parameters of newborn primate endocast reconstruction in open‐access software. Our study found both quantitative and qualitative differences between the models produced by these methods suggesting the chosen method of reconstruction affects the resulting EV measurement. We conclude that a patched semi‐automatic approach with minimal baffles appears to reflect the anatomy with sufficient accuracy, while increasing efficiency and repeatability.

Interspecific variation in avian postcranial pneumaticity: A pilot study

The avian respiratory system is composed of a unidirectionally ventilated, volume‐constant gas‐exchanging lung, and a series of compliant, flexible air sacs. Diverticula from the lungs and air sacs invade adjacent bone and create air‐filled cavities within the skeleton through the process of pneumatization. While previous studies have addressed the presence or absence of pneumatic bones in multiple species, the pattern of pneumatization has been vaguely generalized with respect to which lung elements are responsible for pneumatizing different skeleton regions. Here, we aim to address which components of the avian respiratory system are pneumatizing each component of the postcranial skeleton and how the patterns vary between different taxa. Computed tomography (CT) and microCT data are used to visualize the pneumatized bones and to segment 3D digital surface models of the skeletal and respiratory systems. Specimens used in this study include the African grey parrot (Psittacus erithacus), ostrich (Struthio camelus), red‐tailed hawk. (Buteo jamaicensis), and tundra swan (Cygnus columbianus). We found substantial differences in the pneumatization patterns between the birds. In all taxa examined, there is an extensive supramedullary diverticulum that travels through the vertebral canal which directly pneumatizes each vertebra in the parrots but does not contribute to any pneumatization in the swan or hawk. The sacral, pelvic, and femoral elements are pneumatized solely by pelvic diverticula in the ostrich, but predominantly by the abdominal sacs in parrots. These data indicate that the pneumatization patterns in birds are highly variable and warrant further study.

The Correction of Plagiocephaly

Real Plagiocephaly is a rare form of craniosynostosis, resulting from the premature fusion of the coronal suture on one side, leading to a deformed head and to an apparently exteriorized homolateral eye. We present a simple and straightforward technique, based on removal of the involved suture, with the surgical incision prolonged to the orbital roof till near the ethmoide. After having sectioned the lateral border of the orbit at the junction of the zygomatic and frontal bones, a paramedian incision is made on the frontal bone, from the anterior fontanel (always carefully preserved), till the glabella. Then follows simple osteoclasia of the frontal bone and placement of a bone graft obtained from the adjacent parietal bone and that will maintain the forward projection of the frontal bone (but in slight hypercorrection). The grafts are simply fixed with silk sutures, placed through perforating holes in the bones, no metal being used. The transverse surgical wound, going almost from ear to ear, is closed in the usual way.

Новые лабораторные тесты для оценки эффективности лечения больных с хроническим остеомиелитом костей стопы в условиях использования метода чрескостного остеосинтеза

Introduction The use of laboratory tests to monitor the treatment of patients with chronic osteomyelitis has a lot of clinical relevance. The purpose of the study was to identify laboratory tests for assessing metabolic processes in patients with purulent lesions of the foot bones for monitoring the dynamics of the recovery processes in the course of treatment. Methods The studies were carried out in 36 patients with chronic osteomyelitis of the calcaneus and adjacent bones of the foot of traumatic etiology. All patients were treated with the method of the Ilizarov transosseous osteosynthesis. Biochemical and coagulation parameters were studied. Results It was found that in patients with purulent lesions of the foot bones, the elevated levels of blood serum lactate were most frequently detected before surgery (52.8 %, 95 % CI: 36.6-68.6). The incidence of elevated CRP was 27.7 % (95 % CI: 14.6-43.3) on average, and one third of patients had elevated fibrinogen levels (33.3 %, 95-CI: 19.1-49, 3). During the treatment period, the incidence of elevated lactate levels in patients did not change but the incidence of elevated CRP levels increased significantly which was observed in 77.8 % of patients on the 3rd post-surgery day. By discharge from the hospital, elevated values of CRP and lactate occurred in 11.1 % of patients. It is assumed that the greatest diagnostic significance is the assessment of the level of lactate in the dynamics of the treatment in target patients. Discussion Based on the results of the studies, a laboratory sign was found that indicates the effectiveness of surgical treatment in patients with chronic osteomyelitis of the foot bones using the method of transosseous osteosynthesis. Such a sign is a decrease in the initially elevated concentration of lactate in the blood serum of patients in the postoperative period. The detected sign meets the requirements for its applicability in laboratory tests: 1) this sign is the most common in the target group of patients; 2) the dynamics of changes in the level of lactate correlates with the ongoing treatment; 3) this test is an indicator of a significant physiological process: oxidative metabolic processes in patients with the studied pathology.

Cranial and vertebral osteosarcoma commonly has T2 signal heterogeneity, contrast enhancement, and osteolysis on MRI: A case series of 35 dogs.

Magnetic resonance imaging (MRI) is commonly used to evaluate the central nervous system (CNS) in dogs; however, published studies describing the MRI appearance of cranial and vertebral osteosarcoma are scarce. In this multicenter, retrospective, case series study, MRI studies of 35 dogs with cranial or vertebral osteosarcoma were prospectively scored by consensus of two veterinary radiologists. Recorded characteristics were location, signal intensity (compared to gray matter), homogeneity, contrast enhancement, margin delineation, local invasion, osteolysis, osteosclerosis, zone of transition, periosteal proliferation, pathological fracture, meningeal/CNS involvement, and presence of metastatic disease. Locations included the parietal bone (n=1), occipital bone (n=2), or cervical (n=5), thoracic (n=17), lumbar (n=7), or sacral vertebrae (n=3). Common features included signal heterogeneity in T2-weighted (T2W) images (n=35), contrast enhancement (in all 34 dogs with postcontrast MRI), osteolysis (n=34), compression of the CNS or cauda equina (n=33), an associated soft tissue mass (n=33), a long zone of transition (n=30), osteosclerosis (n=28), signal isointensity to normal-appearing gray matter in T1-weighted images (T1W, n=26), and T2W hyperintensity of adjacent brain or spinal cord (n=23). Other findings included periosteal proliferation (n=18), meningeal contrast enhancement (n=17), T1W and T2W hypointense foci in the soft tissue mass (n=14), invasion into adjacent bones (n=10), pathological vertebral fractures (n=7), regional lymphadenopathy (n=6), skip metastases (n=2), lung nodule (n=1), diaphragmatic nodule (n=1), and brain invasion (n=1). Contrast enhancement was typically strong and heterogeneous. Magnetic resonance imaging features of cranial and vertebral osteosarcoma were analogous to those previously reported for other imaging modalities. Osteosarcoma should be a differential diagnosis for compressive, contrast-enhancing, osteolytic lesions of the cranium or vertebrae.

Solitary Fibrous Tumor of the Spine: Imaging Grading Diagnosis and Prognosis.

This study aimed to investigate the imaging features and prognosis of spinal solitary fibrous tumors (SFTs) of different pathological grades. The clinical features, computed tomography and magnetic resonance (MR) images, and follow-up data of 23 patients with SFTs were reviewed. The patients were divided into 3 groups according to their pathological manifestations: grade 1 (n = 3), grade 2 (n = 14), and grade 3 (n = 6). The following imaging features were recorded: location, computed tomography density/MR intensity, enhancement pattern, dural tail sign, adjacent bone remodeling, lobulation, and tumor size. The immunohistochemical (Ki-67/MIB-1) levels were also investigated. All parameters were statistically analyzed between grade 2 and 3 tumors. The Ki-67/MIB-1 index was markedly higher in grade 3 tumors than in grade 2 tumors ( P < 0.001). All grade 1 lesions appeared hypointense on T2-weighted image, whereas grade 2 and 3 lesions appeared isointense or mildly hyperintense. There were significant differences in enhancement type and osteolytic bony destruction between grade 2 and 3 tumors ( P < 0.05). However, no marked differences were found in the distribution of age, sex, location, MR signal, degree of enhancement, compressive bony absorption, dural tail sign, or maximum vertical/traverse diameter ratio. Malignant progression occurred less frequently in patients with grade 2 tumors than in those with grade 3 tumors, but the difference was not statistically significant. Different grades of spinal SFTs have different degrees of proliferation and imaging features, especially grade 3 tumors, which show a heterogeneous enhancement pattern, osteolytic bony destruction, and a higher possibility of recurrence and metastasis.

Does harvesting cancellous bone destabilize cervical spine in cervical interbody fusion? A prospective clinicoradiological analysis

Background: To analyse the effect of graft harvesting from adjacent vertebral bodies in Anterior Cervical Discectomy and Fusion. Objective: The objective of this study is to analyze the effect of harvesting bone graft from adjacent vertebral bodies on cervical spine stability, vertebral segment height, and cervical lordosis in single-level anterior cervical discectomy and fusion (ACDF). Material and Methods: Thirty patients suffering from cervical radiculopathy and myelopathy were operated on using adjacent corticocancellous bone graft (ACBG) technique. In this technique, autologous cancellous bone is harvested from adjacent vertebral bodies and packed in the intervertebral body cage and the cavities in vertebral bodies are filled with tricalcium phosphate granules. Radiological studies with X-rays of the cervical spine were taken in lateral views preoperatively, immediate postoperatively, and during follow-up periods at intervals of 3-month duration, namely 3, 6, 9, 12 months, and at the end of 2 years postoperatively. Studies undertaken were – degree of fusion using modified Bridewell's formula, disc space settlement using Indigenous method, and vertebral segment height and lordotic angle using Cobb's angle. Results: Satisfactory bony fusion was seen achieved in all patients at the end of 1 year. Although the settlement of disc space was appreciated, vertebral segment height remained increased at the end of 1 year. Cervical lordosis increased over a period of time during fusion process. The average preoperative Cobb's angle of 15.61° ± 1.81° improved to 20° ± 1.37°degrees at the end of 2 years postoperatively. Conclusion: Harvesting bone from adjacent cervical vertebrae does not weaken spinal segment and the fear and skepticism that prevailed over the years are false. ACBG technique is a potential alternative to other existing techniques in ACDF.

Management of External Cervical Resorption in Mandibular Molar Furcation Area - A Case Series

&lt;p&gt;External cervical resorption (ECR) is an aggressive form of root resorption causing loss of tooth structure and sometimes leading to destruction of adjacent alveolar bone. In the advanced extent of ECR lesion, surgical intervention is inevitable. Several studies presented favorable treatment outcomes on advanced ECR lesions at single teeth. In the light of these studies, this article reports on surgical management of two ECR cases. Materials and Methods: Two cases had ECR combined with bony defect in left mandibular first molar. Case 1 had ECR lesion over buccal furcation area combined with buccal bone plate loss. Following root canal treatment, the resorptive defect was restored by mineral trioxide aggregate and the bony defect was treated with guided tissue regeneration (GTR). Case 2 had class II furcation defect with ECR over furcal surfaces of mesial and distal roots. The resorptive defect was restored with bioceramic putty and class II furcation bony defect was treated by GTR. Root canal treatment of tooth 36 was done later after case 2 suffered from symptomatic irreversible pulpitis of tooth 36. Result: At one-year follow-up of case 1, no inflammatory signs with probing pocket depth (PPD) less than 3mm clinically and regeneration of buccal bone plate radiographically were found of tooth 36. At half year follow-up of case 2, there was a healthy gingiva with PPD less than 3mm clinically and the furcation area has been partially filled with regenerated bone radiographically of tooth 36. Conclusion: These case series presented an interdisciplinary surgical management of two cases with external cervical resorption combined with bony defect over lower molar furcation area which were successfully treated with biocompatible restorative material in combination with GTR technique in short-term follow-up.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Magnetic Resonance Imaging Manifestations of Rosai-Dorfman Disease in Central Nervous System

Objective To investigate the clinical and magnetic resonance imaging(MRI) manifestations of Rosai-Dorfman disease(RDD) in central nervous system. Method The clinical and MRI data of 5 cases of RDD in central nervous system confirmed by pathology in the PLA General Hospital were analyzed retrospectively. Results The 5 cases included 4 males and 1 female,aged(39.8±21.7) years on average.Among them,4 cases were located in the intracranial area and 1 case in the thoracic spinal canal.The lesion showed isointense signal on T1 weighted image and iso,slight-hypo,and slight-hyperintense signals on T2 weighted image,and it presented intensively homogeneous enhancement in contrast-enhanced MRI.Two cases showed compressed brain area with edema around the left parietal and left frontotemporal dura,thickening and enhancement in the adjacent dura,and dural tail sign.Three cases presented bone destruction in adjacent diploe and thoracic vertebrae.One case showcased slight-hypo perfusion of the left parietal dura in arterial spin labeling. Conclusions RDD lesion usually appears as iso,slight hypo and slight hyper-intense signals on T2 weighted image and presents intensively homogeneous enhancement in contrast-enhanced MRI.The disease may involve the adjacent bone and the lesion shows slight hypo-perfusion on perfusion images.The MRI manifestations of RDD are characteristic,which are helpful for preoperative diagnosis and evaluation of RDD.

Shoulder MRI evaluation of the association of os acromiale with supraspinatus and infraspinatus injury

To explore the MRI findings of os acromiale and to analyze the relationship between os acromiale and the supraspinatus and infraspinatus injury. From January 2010 to August 2020, 21 patients with os acromiale (os arcomiale group) were compared with 21 subjects with no evidence of os acromiale (no os arcomiale group). There were 14 males and 7 females in the os arcomiate group, aged from 29 to 77 years old, mean aged (55.5±11.5) years old. While in the control group, there were 10 males and 11 females in no os arcomiale group, aged from 31 to 70 years old, mean aged (51.1±10.0) years old. The os acromiales were classified as edematous os acromiale or non-edematous os acromiale based on whether the presence of marrow edema, and as displaced os acromiale or non-displaced os acromiale based on whether the presence of displacement of the os acromiale. The MRI features of os acromiale were analyzed. Statistical analyses were performed to identify the differences between the os arcomiale group and no os arcomiale group regarding rotator cuff tear, supraspinatus and infraspinatus injury. Differences in the supraspinatus and infraspinatus tear between the edematous and non-edematous os acromiale group, the displaced and non-displaced os acromiale group, the displaced os acromiale and no os arcomiale group were also assessed. On MRI, all the 21 os acromiales appeared as a triangular or irregular bone fragment of the distal acromion, and forms a pseudo-acromioclavicular joint with the acromion. Eleven cases were edematous os acromiale, 11 cases were displaced os acromiale. In the os arcomiale group, 17 had supraspinatus tear, 1 had supraspinatus tendinitis, 11 had infraspinatus tear, and 4 had infraspinatus tendinitis. In the no os arcomiale group, 11 had supraspinatus tear, 2 had supraspinatus tendinitis, 5 had infraspinatus tear, and 1 had infraspinatus tendinitis. No statistically significant difference between the os arcomiale group and no os arcomiale group regarding the rotator cuff tear, supraspinatus and infraspinatus injury (P>0.05). In the 11 cases of edematous os arcomiale, 10 had supraspinatus tear and 7 had infraspinatus tear. In the 10 cases of non-edematous os acromiale, 7 had supraspinatus tear and 4 had infraspinatus tear. No statistically significant difference was noted between the edematous os acromiale and non-edematous os acromiale in terms of supraspinatus and infraspinatus tear (P>0.05). In the 11 cases of displaced os acromiale, 11 had supraspinatus tear and 9 had infraspinatus tear. In the 10 cases of non-displaced os acromiale, 6 had supraspinatus tear and 2 had infraspinatus tear. In the no os arcomiale group, 11 had supraspinatus tear and 5 had infraspinatus tear. There was a statistically significant increases in the prevalence of supraspinatus and infraspinatus tear in the displaced os acromiale group compared with non-displaced os acromiale group, the displaced os acromiale group and no os arcomiale group(P<0.05). Shoulder MRI can very well depict os acromiale and can reveal associated abnormalities such as adjacent bone marrow edema, displaced deformity, and rotator cuff tear, and it can be used to assess the stability of the os acromiale. The presence of os acromiale may not increase the risk of supraspinatus and infraspinatus tear significantly. However, the presence of displaced os acromiale is at greater risk of supraspinatus and infraspinatus tear.

Engineering hypertrophic cartilage grafts from lipoaspirate for critical-sized calvarial bone defect reconstruction: An adipose tissue-based developmental engineering approach.

Developmental engineering of living implants from different cell sources capable of stimulating bone regeneration by recapitulating endochondral ossification (ECO) is a promising strategy for large bone defect reconstruction. However, the clinical translation of these cell‐based approaches is hampered by complex manufacturing procedures, poor cell differentiation potential, and limited predictive in vivo performance. We developed an adipose tissue‐based developmental engineering approach to overcome these hurdles using hypertrophic cartilaginous (HyC) constructs engineered from lipoaspirate to repair large bone defects. The engineered HyC constructs were implanted into 4‐mm calvarial defects in nude rats and compared with decellularized bone matrix (DBM) grafts. The DBM grafts induced neo‐bone formation via the recruitment of host cells, while the HyC pellets supported bone regeneration via ECO, as evidenced by the presence of remaining cartilage analog and human NuMA‐positive cells within the newly formed bone. However, the HyC pellets clearly showed superior regenerative capacity compared with that of the DBM grafts, yielding more new bone formation, higher blood vessel density, and better integration with adjacent native bone. We speculate that this effect arises from vascular endothelial growth factor and bone morphogenetic protein‐2 secretion and mineral deposition in the HyC pellets before implantation, promoting increased vascularization and bone formation upon implantation. The results of this study demonstrate that adipose‐derived HyC constructs can effectively heal large bone defects and present a translatable therapeutic option for bone defect repair.

Analytical Modeling of the Interaction of a Four Implant-Supported Overdenture with Bone Tissue

Today, an interdisciplinary approach to solving the problems of implantology is key to the effective use of intraosseous dental implantations. The functional properties of restoration structures for the dentition depend significantly on the mechanical stresses that occur in the structural elements and bone tissues in response to mastication loads. An orthopedic design with a bar fixation system connected to implants may be considered to restore an edentulous mandible using an overdenture. In this study, the problem of the mechanics of a complete overdenture based on a bar and four implants was formulated. A mathematical model of the interaction between the orthopedic structure and jawbone was developed, and a methodology was established for the analytical study of the stress state of the implants and adjacent bone tissue under the action of a chewing load. The novelty of the proposed model is that it operates with the minimum possible set of input data and provides adequate estimates of the most significant output parameters that are necessary for practical application. The obtained analytical results are illustrated by two examples of calculating the equivalent stresses in implants and the peri-implant tissue for real overdenture designs. To carry out the final assessment of the strength of the implants and bone, the prosthesis was loaded with mastication loads of different localization. In particular, the possibilities of loading the prosthesis in the area of the sixth and seventh teeth were investigated. Recommendations on the configuration of the distal cantilever of the overdenture and the acceptable level and distribution of the mastication load are presented. It was determined that, from a mechanical point of view, the considered orthopedic systems are capable of providing long-term success if they are used in accordance with established restrictions and recommendations.