Clinical and Histological Efficacy of Digitally Designed CAD CAM Allogenic Bone Blocks. A Prospective Cohort.

The growth in bone reconstructive surgery has been unsurpassed in recent decades. However, most bone regenerative products lack any potential for delivering site-specific morphologically driven augmentation. It was therefore the purpose of this study to evaluate the histological and clinical incorporation of a novel CAD CAM allogenic block bone graft for the reconstruction of complex 3- dimensional alveolar defects. In addition the clinical outcome of dental implants subsequently placed and loaded within these grafts was assessed with up to 5 years in function. Results demonstrated that 4 of the initial 17 blocks failed (23.5%). The remaining 13 blocks plus an additional two replacement blocks were fully or partially incorporated within the recipient bone site (79%). Of the 29 implants placed within the integrated blocks, no failures occurred with up to 5 years in function, with a recorded mean marginal bone loss by implant of -0.5mm.

Establishing a bone bank within a hospital setting in India: early insights from a tertiary care center in Northern India-a review article.

When addressing bone defects resulting from trauma, infection, or tumors, the use of allogenic bone is often necessary. While autografts are considered the standard, they have limitations and can lead to donor site morbidity. Consequently, there has been exploration into the feasibility of utilizing allogenic bone and bone graft replacements. Allogenic bone transplants are acquired from donors following rigorous procurement, sterile processing, and donor screening procedures. To ensure the safe storage and effective utilization of allograft material, a bone banking system is employed. Establishing and managing an orthopedic bone bank, entails navigating complex legal and medical organizational aspects. This paper examines the establishment and operation of bone banks in India, drawing upon our first-hand experience in managing one at a tertiary care center in Northern India.Level of evidence: Level IV.

T-Cell Lymphoproliferative Disorders Following Allogeneic Bone Marrow Transplant: A Report of Two Cases and a Literature Review.

Post-transplantation lymphoproliferative disorders (PTLD) are a commonly occurring condition following solid organ transplantation (SOT) and, rarely, hematopoietic stem cell transplantation (HSCT). As the name suggests, a PTLD is a condition where there is a clonal proliferation of lymphoid cells that occurs as a complication after transplantation. Though the clonal origin cell is primarily associated with the B-cell lineage, there are existing cases in the literature describing PTLD from the T-cell lineage. Large granulocytic leukemia (LGL) is one rare T-cell lineage subtype that typically progresses with a passive clinical course and is discovered with leukocytosis and peripheral blood smears demonstrating large granules in lymphocytes. In this study, we describe two patients initially diagnosed with acute myeloid leukemia (AML) who were both found to have T-cell PTLD after undergoing allogeneic hematopoietic stem cell transplant. One was found with a clonal expansion of T-cells on flow cytometry and the other with LGL on peripheral blood and flow cytometry. This discovery was made at 16 and 20 months after their transplant respectively. Distinguishing factors for these two patients are demonstrated by the derivation of lymphoproliferative disorder from graft vs. host disease (GVHD) or viral etiology, which is significant as both of which have been shown to be associated with PTLD. Epstein-Barr virus (EBV) and cytomegalovirus (CMV) positivity have been shown to be associated with PTLD, and both our patients were EBV-negative but had harbored prior CMV infections. Additionally, they had a benign course with no development of cytopenias or symptoms since the time of diagnosis. These two cases add to the growing literature that is working to better characterize the rare development of LGL and, in general, T-cell PTLD following allogeneic bone marrow transplantation.

Minimally invasive treatment of benign osteolytic bone lesions with a Hartmann ear speculum: A surgical technique.

This study introduces a novel and simple minimally invasive technique for treating benign osteolytic bone lesions. The standard treatment involves lesion removal and cavity filling with various materials. Minimally invasive approaches, including arthroscopy and CT-guided injection, have been described, but they pose challenges such as X-ray exposure and expansiveness. In this study, a new minimally invasive technique using a Hartmann ear speculum is presented. The technique was successfully applied in 10 patients with various benign tumors, demonstrating full healing and no recurrence at one-year follow-up. The presented approach combines simplicity, cost-effectiveness, and minimal invasiveness, making it a promising alternative option for treating benign bone lesions with low complication rates and surgical site morbidity. LEVEL OF EVIDENCE: IV.

Evaluation of Circulating Endothelial Cells as Direct Marker of Endothelial Damage in Allo-Transplant Recipients at High Risk of Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome.

Sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease (VOD), is a rare but potentially fatal complication following allogenic hematopoietic cell transplantation (allo-HCT). Timely identification of SOS/VOD to allow for prompt treatment is critical, but identifying a VOD-predictive biomarker remains challenging. Given the pivotal role of endothelial dysfunction in SOS/VOD pathophysiology, the CECinVOD study prospectively evaluated levels of circulating endothelial cells (CECs) in patients undergoing allo-HCT with a myeloablative conditioning (MAC) regimen to investigate the potential of CEC level in predicting and diagnosing SOS/VOD. A total of 150 patients from 11 Italian bone marrow transplantation units were enrolled. All participants were age >18 years and received a MAC regimen, putting them at elevated risk of developing SOS/VOD. Overall, 6 cases of SOS/VOD (4%) were recorded. CECs were detected using the Food and Drug Administration-approved CellSearch system, an immunomagnetic selection-based platform incorporating ferrofluid nanoparticles and fluorescent-labeled antibodies, and were defined as CD146+, CD105+, DAPI+, or CD45-. Blood samples were collected at the following time points: before (T0) and at the end of conditioning treatment (T1), at neutrophil engraftment (T2), and at 7 to 10 days postengraftment (T3). For patients who developed VOD, additional samples were collected at any suspected or proven VOD onset (T4) and weekly during defibrotide treatment (T5 to T8). A baseline CEC count >17/mL was associated with an elevated risk of SOS/VOD (P = .04), along with bilirubin level >1.5 mg/mL and a haploidentical donor hematopoietic stem cell source. Postconditioning regimen (T1) CEC levels were elevated (P = .02), and levels were further increased at engraftment (P < .0001). Additionally, patients developing SOS/VOD after engraftment, especially those with late-onset SOS/VOD, showed a markedly higher relative increase (>150%) in CEC count. Multivariate analysis supported these findings, along with a high Endothelial Activation and Stress Index (EASIX) score at engraftment (T2). Finally, CEC kinetics corresponded with defibrotide treatment. After the start of therapy (T4), CEC levels showed an initial increase in the first week (T5), followed by a progressive decrease during VOD treatment (T6 and T7) and a return to pre-SOS/VOD onset levels at resolution of the complication. This prospective multicenter study reveals a low incidence of SOS/VOD in high-risk patients compared to historical data, in line with recent reports. The results from the CECinVOD study collectively confirm the endothelial injury in allo-HCT and its role in in the development of SOS/VOD, suggesting that CEC level can be a valuable biomarker for diagnosing SOS/VOD and identifying patients at greater risk of this complication, especially late-onset SOS/VOD. Furthermore, CEC kinetics may support treatment strategies by providing insight into the optimal timing for discontinuing defibrotide treatment.

Hydatid Disease of Tibia Reconstructed with Allograft: A Rare Case Report and Literature Review.

Background: Hydatid disease of bone shows a well-defined, multiloculated lytic lesion with the appearance of a bunch of grapes. The presenting symptoms are pain and swelling with or without pathological fracture. The treatment options include surgery followed by a long duration of albendazole. Removal of the involved bone is required to decrease the chances of recurrences. Case Report: In our study, we have included a case of 28-year-old woman presented with complaints of pain and difficulty in weight bearing over her right lower limb for 2.5 months. Radiograph suggested an eccentric lytic lesion in midshaft of tibia and biopsy revealed granulosus cyst wall, nucleate germinal layer, the brood capsule, and protoscolices with visible hooklets. Patient was subjected to surgery with the excision of cyst along with extended curettage of bone creating a bone defect around the lesion and with anterolateral platting with coverage of bone defect by allogenic bone grafting. Patient was kept on above knee slab with non-weight-bearing mobilization for 6 weeks. Postoperative chemotherapy with Albendazole was given for 3 months. Patient was followed up every 6 weeks for 3 months and every month thereafter on outpatient basis. Return to work and patient satisfaction were excellent. Conclusion: Definitive Surgical management with Preoperative and postoperative chemotherapy seems to be effective to avoid recurrence. The bone defect caused by the disease or surgery can be managed with a bone graft either of autograft or allograft.

Research on the Influence of the Allogeneic Bone Graft in Postoperative Recovery After MOWHTO: A Retrospective Study.

Purpose: To compare the effects of an allogeneic bone graft and a non-filled bone graft on the rate of osteotomy gap union in medial opening wedge high tibial osteotomy (MOWHTO) with an opening width less than 10 mm. Methods: A total of 65 patients undergoing MOWHTO between January 2018 and December 2020 were enrolled in this retrospective study. The patients were divided into two groups: the allograft group (MOWHTO with allogeneic bone grafting, 30 patients) and the non-filling group (MOWHTO without bone void fillers, 35 patients). The clinical outcomes, including the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), Lysholm score, and post-operative complications, were compared. The radiographic evaluation included changes in hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), femorotibial angle (FTA), and weight-bearing line ratio (WBLR) at pre-operation, at two-day post-operation, and the last follow-up. Radiographs were obtained at three, six and twelve months post-surgery, and at the time of the last follow-up to assess the fill area of the osteotomy gap. The union rate of the osteotomy gap was calculated and compared, and risk factors that may affect the rate of osteotomy gap union were also discussed. Results: The rate of osteotomy gap union at 3 and 6 months after the operation in the allograft group was significantly higher compared with the non-filling group (all P<0.05), while no significant difference was found after the 1-year post-operative and at the last follow-up. Also, the WOMAC and Lysholm scores of the allograft group were significantly higher than those of the non-filling group (all P<0.05), and there was no significant difference between the two groups at the last follow-up. Conclusion: Filling the gaps with the allograft bones may accelerate the union of osteotomy gap, improve clinical outcomes, and have important implications for patient rehabilitation in the early post-operative course. Bone grafting did not affect the final rate of osteotomy gap union and the clinical score of patients.

Implant Materials for Anterior Column Reconstruction of Cervical Spine Tumor.

The spine is the most common site of bone metastases. Many cancer patients will ultimately develop spinal metastatic disease with symptomatic epidural spinal cord compression. At present, the main treatment for cervical spine tumors is surgical resection combined with postoperative radiotherapy. Implant materials for cervical spine anterior column reconstruction need to meet amounts of different properties, such as biocompatibility, bioactivity and the ability to maintain long-term mechanical strength. The selection of different materials determines the surgical efficacy and prognosis of patients to a certain extent. This article provides an overview of a variety of implant materials used for anterior column reconstruction after cervical spine tumor resection, introduces and analyzes their properties, advantages, disadvantages, derivatives, and applications in clinical practice, and looks forward to the future development of implant materials.

Effects of Allogeneic Bone Substitute Configurations on Cell Adhesion Process In Vitro.

OBJECTIVE: To explore the potential effect of three allogenic bone substitute configurations on the viability, adhesion, and spreading of osteoblasts in vitro. METHODS: Freeze-dried cortical bone were ground and fractions were divided into three groups with different sizes and shapes, defined as bone fiber (0.1 mm × 0.1 mm × 3 mm), bone powder (0.45-0.9 mm), and bone granule group (3-6 mm). MC3T3-E1 cells were divided and co-cultured within groups to induce cell adhesion. The configuration of allogenic bone was captured by scanning electron microscopy and confocal laser scanning microscopy, and substrate roughness values were quantified. Cell adhesion rate was assessed using the hemocyte counting method, cell viability was determined by CCK-8 assay and live/dead staining, and cell morphology was visualized by Phalloidin and DAPI, and the mRNA expression of adhesion-related gene (vinculin) of different substitutes were determined with quantitative real-time polymerase chain reaction. RESULTS: The roughness values of bone fiber, bone powder, and bone granule group were 1.878 µm (1.578-2.415 µm), 5.066 µm (3.891-6.162 µm), and 0.860 µm (0.801-1.452 µm), respectively (bone powder group compared with bone granule group, H = 18.015, P < 0.001). Similar OD values of all groups in CCK-8 assay indicated good biocompatibility of these substitutes (bone fiber, 0.201 ± 0.004; bone powder, 0.206 ± 0.008; bone granule group, 0.197 ± 0.006; and the control group, 0.202 ± 0.016, F = 0.7152, P > 0.05). In addition, representative cell adhesion rates at 24 h showed significantly lower cell adhesion rate in bone fiber group (20.3 ± 1.6%) compared to bone powder (29.3 ± 4.4%) and bone granule group (27.3 ± 3.2%) (F = 10.51，P = 0.009 and P = 0.034, respectively), but there was no significant difference between the latter two groups (P > 0.05). Interestingly, the expression of vinculin mRNA steadily decreased in a time-dependent manner. The vinculin expression reached its peak at 6 h in each group, and the vinculin levels in bone fiber, bone powder, and bone granule group were 2.119 ± 0.052, 3.842 ± 0.108, and 3.585 ± 0.068 times higher than those in the control group, respectively (F = 733.643, all P < 0.001). Meanwhile, there was a significant difference in the expression of target gene between bone powder and bone granule group (P = 0.006). CONCLUSION: All allogenic bone substitutes presented an excellent cell viability. Moreover, bone powder and bone granule group were more likely to promote cell adhesion and spreading compared to bone fiber group.

The Application of an Allogenic Bone Screw for Stabilization of a Modified Chevron Osteotomy: A Prospective Analysis.

Background: Distal first metatarsal osteotomies are commonly performed operative procedures for hallux valgus deformity, and usually involve fixation with a metal screw. However, various bioabsorbable osteosynthesis materials have been in use for a number of years. One recent innovation is the Shark Screw®, a human cortical bone allograft. This study aimed to evaluate the efficacy and safety of this allogeneic screw in the stabilization of Reversed L-Shaped osteotomy, a modified Chevron osteotomy. Methods: In a prospective study, 15 patients underwent a Reversed L-Shaped osteotomy stabilized with the allogenic bone screw Radiological data on osteointegration of the screw and correction of the intermetatarsal angle were recorded. Furthermore, each follow-up examination included the collection of clinical data, the American Orthopedic Foot and Ankle Society (AOFAS) score, evaluation of pain level, and patient's overall satisfaction. Results: Full osseous fusion of the osteotomy was seen in all patients. The bone screws were radiographically integrated after approximately 6.5 (±2.6) months. Neither nonunion nor failure occurred in any of our cases. Furthermore, we did not find any potential graft reaction. The AOFAS score improved significantly from 51.6 (±15.2) points to 90.9 (±10.3) (p < 0.001). The preoperative hallux valgus angle and intermetatarsal angle decreased significantly from 24.8 (±4.9) degrees to 7.2 (±4.4) degrees (p < 0.001) and 12.6 (±3.2) degrees to 4.8 (±1.3) degrees (p < 0.001), respectively. Conclusions: With this study, we demonstrated the efficiency of the allogenic bone screw (Shark Screw®) in regard to clinical and radiological short-term outcomes.

Two-stage bone and meniscus allograft and autologous chondrocytes implant for unicompartmental osteoarthritis: midterm results.

BACKGROUND: We analyzed the clinical and radiographic evolution of patients with knee unicompartmental osteoarthritis and axis alteration and osteochondral lesions in the femoral condyle, treated with tibial plateau and meniscus allograft and cultured autologous chondrocyte implantation in the femur in two steps. PURPOSE: To analyze the clinical results with the first patients treated with this two-stage technique to avoid knee prosthesis in patients with unicompartmental osteoarthritis. MATERIAL AND METHODOLOGY: Sixteen patients, average age 56 years, were included in a cohort study. We performed an osteotomy with tibia plateau allograft, including the meniscus. In a second surgery, the chondrocyte fibrin scaffold was placed in the femur. Clinical symptoms and function were measured using KSSR and KOOS scores. Wilcoxon's test was performed to compare the results over the 2-year follow-up period. RESULTS: Mean KSSR before surgery was 35.69 (SD: 3.75) points, rising to 67 (SD: 15.42) at 3 months, 95.88 at 12 months (SD: 2.68) and 96.31 at 24 months (SD: 2.24). The KOOS before surgery was 65.14 (SD: 16.34), rising to 72.68 after 3 months (SD: 19.15), 76.68 at 12 months (SD: 18.92) and 64.28 at 24 months (SD: 11.79). Four of 5 patients returned to engaging in the activity that they had stopped practicing. Three patients experienced collapse of the tibia allograft, and they needed later a prosthesis. CONCLUSIONS: Simultaneous tibia plateau allograft and autologous chondrocyte implantation in the femur, after correction of the angular deformity, were performed, restoring the anatomy of the medial compartment and knee function in 82% of the patients 2 years after the operation. LEVEL OF EVIDENCE: IV.

The Role of Allogeneic Stem Cell Transplantation in Multiple Myeloma: A Systematic Review of the Literature.

Multiple myeloma (MM) is an indolent B-cell malignancy, where treatment is aimed at preventing organ dysfunction from light chain accumulation (slowing disease progression) and inducing remission. Allogeneic stem cell transplant (allo-SCT), through graft versus myeloma (GVM) effects, has the potential to induce remission to a potentially curative-like state. In this systematic review, we aimed to understand this relationship to the risks and severity of disease in categorized patients and gain an updated comprehension of the future of allo-SCT in MM treatment. We conducted this review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and searched the PubMed database to obtain the specified literature with both the use of keywords and Medical Subject Headings (MeSH). A total of 16 relevant articles were included for discussion after the quality appraisal was completed, as appropriate, by either the Cochrane tool or Newcastle-Ottawa checklist. Our review concludes that while allo-SCT may benefit high-risk patients, successful procedures may incorporate a tandem autologous hematopoietic stem cell transplant approach in combination with novel pharmacologic contributions for which there is an observed synergy in the modulation of the immunologic microenvironment. Furthermore, tailored patient selection by evaluating pre-transplant factors including high-risk cytogenetics, age, and pre-salvage International Staging System (ISS) can predict post-transplantation success including non-relapse mortality. Successive research should continue to revise and update treatment options as the evolving therapeutic drug regimens may change over the course of indolent disease.

A Novel Screw Drive for Allogenic Headless Position Screws for Use in Osteosynthesis-A Finite-Element Analysis.

Due to their osteoconductive properties, allogenic bone screws made of human cortical bone have advantages regarding rehabilitation compared to other materials such as stainless steel or titanium. Since conventional screw drives like hexagonal or hexalobular drives are difficult to manufacture in headless allogenic screws, an easy-to-manufacture screw drive is needed. In this paper, we present a simple drive for headless allogenic bone screws that allows the screw to be fully inserted. Since the screw drive is completely internal, no threads are removed. In order to prove the mechanical strength, we performed simulations of the new drive using the Finite-Element method (FEM), validated the simulations with a prototype screw, tested the novel screw drive experimentally and compared the simulations with conventional drives. The validation with the prototype showed that our simulations provided valid results. Furthermore, the simulations of the new screw drive showed good performance in terms of mechanical strength in allogenic screws compared to conventional screw drives. The presented screw drive is simple and easy to manufacture and is therefore suitable for headless allogenic bone screws where conventional drives are difficult to manufacture.

Biofabrication of allogenic bone grafts using cellularized amniotic scaffolds for application in efficient bone healing.

INTRODUCTION: The reconstruction/regeneration of human bone injuries/defects represents a crucial challenge due to the lack of suitable bio/immune compatible and implantable biological grafts. The available strategies represent implications of several types of grafting materials in the form of metals, synthetic, and various kinds of biological scaffolds; however, the lack of appropriate biological components required for activating and enhancing repair mechanisms at the lesion-site limits their wider applicability. METHODS: In this study, a unique approach for generating human osteogenic implantable grafts was developed using biofabrication technology. Using a gradient change of detergents and continuous agitation, developed a unique technique to generate completely cell-free amnion and chorion scaffolds. The absence of cellular components and integrity of biological and mechanical cues within decellularized human amnion (D-HAM) and chorion (D-HCM) were evaluated and compared with fresh membranes. Allogenic bone grafts were prepared through induction of human mesenchymal stem cells (hMSCs) into osteogenic cells on D-HAM and D-HCM and evaluated for their comparative behavior at the cellular, histological and molecular levels. RESULTS: The common decellularization process resulted in an efficient way to generate D-HAM and D-HCM while retaining their intact gross-anatomical architecture, surface morphology, extracellular matrix components, and mechanical properties. Both these scaffolds supported better growth of human umbilical cord blood derived MSCs as well as osteogenic differentiation. Comparative investigation revealed better growth rate and differentiation on D-HCM compared to D-HAM and control conditions. CONCLUSION: D-HCM could be used as a better choice for producing suitable allogenic bone grafts for efficient bone healing applications.

A comparative study of autogenous, allograft and artificial bone substitutes on bone regeneration and immunotoxicity in rat femur defect model.

Repair and reconstruction of large bone defect were often difficult, and bone substitute materials, including autogenous bone, allogenic bone and artificial bone, were common treatment strategies. The key to elucidate the clinical effect of these bone repair materials was to study their osteogenic capacity and immunotoxicological compatibility. In this paper, the mechanical properties, micro-CT imaging analysis, digital image analysis and histological slice analysis of the three bone grafts were investigated and compared after different time points of implantation in rat femur defect model. Autogenous bone and biphasic calcium phosphate particular artificial bone containing 61.4% HA and 38.6% ß-tricalcium phosphate with 61.64% porosity and 0.8617 ± 0.0068 g/cm3 density (d ≤ 2 mm) had similar and strong bone repair ability, but autogenous bone implant materials caused greater secondary damage to experimental animals; allogenic bone exhibited poor bone defect repair ability. At the early stage of implantation, the immunological indexes such as Immunoglobulin G, Immunoglobulin M concentration and CD4 cells' population of allogenic bone significantly increased in compared with those of autologous bone and artificial bone. Although the repair process of artificial bone was relatively inefficient than autologous bone graft, the low immunotoxicological indexes and acceptable therapeutic effects endowed it as an excellent alternative material to solve the problems with insufficient source and secondary trauma of autogenous bone.

Experimental study on repair of large segmental bone defects of goat femur by nano calcium-deficient hydroxyapatite-multi (amino acid) copolymer membrane tubes.

OBJECTIVE: The purpose of this study was to observe feasibility of nano calcium-deficient hydroxyapatite-multi (amino acid) copolymer (n-CDHA-MAC) membrane tubes in repairing goat femurs' large defects. METHODS: Twelve goats were divided into two groups, whose femurs were created 30 mm segmental bone defects and then implants were performed. In experimental group, the bone defect of right femur was reconstructed by n-CDHA-MAC membrane tube, while left side was reconstructed by allogenic bone tube in control group. Every three goats were sacrificed at 4, 8, 16, 24 weeks after operation respectively. General observation, X-ray analysis, histology, Scanning electron microscope (SEM) examination and protein level comparison of BMP-2 were conducted to evaluate the effects of repairing segmental bone defects. RESULTS: All goats recovered well from anesthesia and surgical interventions. The radiographic evaluations showed that periosteal reaction outside of the membrane tubes and allogenic bone tubes were observed 4 weeks after surgery. At 16 weeks, callus was continuously increased in experimental group, which was more obvious than control group. At 24 weeks, callus outside of the membrane tubes connected together. Histologic evaluation showed fibro-cartilage callus was evolved into bony callus in experimental group, which was more obvious than control group at 8 and 16 weeks. The protein expression level of BMP-2 increased at 4, 8 weeks and peaked at 16 weeks in experimental groups. There were statistical differences at 8 and 16 weeks (P < 0.05). At each time point in 8, 16, 24 weeks after surgery, the bending stiffness, torsional stiffness and compressive strength of the two groups were similar, and there was no significant difference (P > 0.05). CONCLUSIONS: This novel surface degradation n-CDHA-MAC membrane tube has good ability to maintain enough membrane space, which can provide long-term and stable biomechanical support for large bone defects and integrate well with the surrounding bone.

Early functional recovery after two-stage surgery with an allogenic bone graft for baseplate loosening in reverse shoulder arthroplasty: a case report.

OBJECTIVES: Reverse shoulder arthroplasty (RSA) for cuff tear arthropathy results in good shoulder function. However, RSA is associated with several complications, including infection, dislocation of the shoulder joint, implant loosening, and axillary nerve palsy. Several problems may also occur on the glenoid side, including bone defects of the glenoid, baseplate loosening, and displacement of the sphere. Herein, we report a 79-year-old man who obtained early functional recovery following a two-stage operation with an allogenic bone graft to treat baseplate loosening and a glenoid bone defect after RSA. CASE REPORT: The patient presented with pain during motion and limited active shoulder joint movement 5 weeks after undergoing RSA for cuff tear arthropathy. CT revealed baseplate loosening and a glenoid bone defect; these complications were treated via a two-stage operation. The first stage comprised the removal of all implants and the grafting of allogenic bone from the femoral head into the glenoid defect. Six months later, CT confirmed complete union of the grafted bone and glenoid. The second stage comprised the re-insertion of all implants. Two months after the last operation, the active shoulder range of motion of the affected side was almost identical to that of the contralateral side. CONCLUSION: Good early functional recovery was obtained using a two-stage operation for baseplate loosening after RSA. Allogenic bone grafting was effective in the reconstruction of the glenoid defect.

Paradoxical Regulation of Allogeneic Bone Marrow Engraftment and Immune Privilege by Mesenchymal Cells and Adenosine.

Although mesenchymal stromal cell (MSC) transfer has long drawn attention owing to its immunosuppressive potential to treat immune-mediated diseases, the role of endogenous MSCs in immune regulation in vivo has remained largely unclear. MSCs constitute the hematopoietic stem cell (HSC) niche, perhaps contributing to immune protection of HSCs, termed immune privilege. Our recent study demonstrates that immune privilege of HSCs is endowed by niche-residential regulatory T cells (Tregs), which promote allogeneic HSC engraftment. This immune privilege depends on cell surface ectoenzymes CD39 and CD73 on niche Tregs, which generate extracellular adenosine, a nucleotide known to suppress immunity and potentiate Tregs. Another niche constituent, leptin receptor-expressing (lepr+) perivascular MSCs, also highly express CD39 and CD73, prompting us to study their roles in immune privilege. This work demonstrates an unexpected negative regulation of immune privilege by MSC-derived adenosine. CD39 deletion in lepr+ cells increased and potentiated effector memory-like niche Tregs, promoting allogeneic HSC engraftment. CD39 deletion in Tregs also activated niche Tregs, while abrogating engraftment. These observations demonstrate paradoxical effects of MSC-derived adenosine to activate immunity, revealing a previously undescribed dual roles of adenosine. Adenosine from both Tregs and MSCs inhibits niche Tregs, whereas adenosine from Tregs, but not that from MSCs, acts as an effector molecule of immune privilege.

Periodontal approach in the management of alveolar cleft.

The alveolar cleft is a bone-related developmental defect in the alveolar process of the maxillae, which is termed as cleft alveolus. The deformity occurs in 75% of the cleft palate and lip patients. Reconstructive surgery can provide both functional and esthetic benefits to such individuals. Conflicting opinions exist on the management of alveolar cleft, and these affect the treatment planning. We present the case of a 19-year-old female patient with a complaint of mobile teeth in the left frontal region of the upper jaw. On clinical examination, unilateral cleft alveolus was observed between the left lateral incisor and the canine region. A multidisciplinary approach was adopted, orthodontic treatment was started, and periodontal regenerative surgery was planned. This report also discusses the substitution of autogenous bone grafts with other materials such as allogenic grafts (demineralized freeze-dried bone allograft), platelet-rich plasma, platelet-rich fibrin membranes, and amnion membranes, which could serve as a new line of treatment for the condition.

Sternal reconstruction after post-sternotomy dehiscence and mediastinitis.

PURPOSE: Post-sternotomy dehiscence and mediastinitis remains a serious complication in cardiothoracic surgery. The aim of this work is to report our experience over a period of 8 years in the surgical treatment and risk factor analyses of post-sternotomy dehiscence and mediastinitis. METHODS: All patients treated for post-sternotomy dehiscence at our Thoracic Surgery Unit in the last 8 years were retrospectively collected. We identified 237 patients with post-sternotomy dehiscence/mediastinitis. Forty-two patients had simple fractures of the metal steel wires, 61 had an asymmetric sternotomy with multiple sternal fractures, 113 had a symmetric sternotomy with multiple sternal fractures, 14 had a failed Robicsek procedure, and 7 had sternal dehiscence with mediastinal abscess. RESULTS: Different surgical techniques and materials were used to repair the sternum. In 21 patients, the first revision failed and a second reoperation was required. At multivariate analyses, we have identified risk factors for revision failure and in-hospital mortality. Mortality rate was significantly higher in patients who underwent more than one surgical revision (8% vs 19%, p < 0.001). CONCLUSIONS: Patients with sternal dehiscence are very fragile due to multiple preoperative comorbidities as reflected by postoperative morbidity and risk factors for in-hospital mortality. A correct evaluation of the characteristics of sternal dehiscence is important to guide the most appropriate repair strategy. Patients who need repeated sternal revisions had a higher mortality. Further randomized studies are needed to evaluate different techniques and medical devices to define the gold standard procedure to reduce significantly sternal wound complications in high-risk patients as defined by well-known risk factors.