Remained Large Bone Fragment of Bony Bankart Lesion in Shoulders With a Subcritical Glenoid Defect at Recurrent Anterior Instability

Background: A preoperative glenoid defect of 13.5% or larger is recognized as a subcritical glenoid defect at arthroscopic Bankart repair (ABR) for collision/contact athletes or military personnel. Purpose: To clarify the prevalence and size of remaining bone fragments in shoulders with a subcritical glenoid defect at recurrent anterior instability and to investigate the influence on postoperative recurrence after ABR for younger competitive athletes. Study Design: Cohort study; Level of evidence, 4. Methods: The study included 96 shoulders with recurrent instability that underwent ABR between July 2011 and March 2018 for shoulders with a subcritical glenoid defect. The patients were divided into 2 groups according to the glenoid defect size (13.5%-<20%, medium; ≥20%, large). The bone fragment size in each defect group was retrospectively investigated and classified into 4 groups (no, 0%; small, >0%-<5%; medium, 5%-<10%; large, ≥10%). The postoperative recurrence rate for each combination of glenoid defect size and bone fragment size was investigated for competitive athletes aged <30 years. The fragments, when present, were repaired to the glenoid. Results: The glenoid defect size was 13.5%-<20% in 60 shoulders (medium defect group) and ≥20% in 36 shoulders (large defect group). The mean bone fragment size was 6.7% ± 5.1% and 8.9% ± 4.9%, respectively ( P = .042). In the medium defect group, there were 15 shoulders (25%) without a bone fragment, 6 shoulders (10%) with a small fragment, 23 shoulders (38.3%) with a medium fragment, and 16 shoulders (26.7%) with a large fragment. In the large defect group, the respective numbers were 2 shoulders (5.6%), 6 shoulders (16.7%), 14 shoulders (38.9%), and 14 shoulders (38.9%). A medium or large bone fragment was more common in the large defect group ( P = .252). Among 64 younger competitive athletes who underwent ABR with a minimum of 2 years of follow-up, postoperative recurrence was recognized in 7 of 38 (18.4%) athletes in the medium defect group, but it was not recognized in any of the 26 athletes in the large defect group ( P = .036). Postoperative recurrence was recognized in 4 of 12 (33.3%) athletes with a small fragment or no fragment and in 3 of 52 (5.8%) athletes with a medium or large fragment ( P = .019). Conclusion: A larger bone fragment frequently remained in shoulders with a subcritical glenoid defect at recurrent instability. The postoperative recurrence rate after ABR for younger competitive athletes was low when a remaining larger bone fragment was repaired.

SP1.1.15Long-term Outcomes of Open Verses Closed Rectal Defect After Transanal Endoscopic Microscopic Surgery

Aims Management of rectal defect after TEMS is a matter of debate. Data are lacking on the effect of these techniques on long term outcomes and continence of patients. We sought to analyse these in our patient cohort. Methods Patients who underwent TEMS between 2012 and 2019 were examined retrospectively from a prospectively maintained database. These were divided into two groups – open and closed rectal defect. Patient demographics were recorded and outcomes assessed including oncological staging, morbidity, mortality, length of stay and FISI scores. Results 170 matched patients were included, with 70 patients in the open and 100 in the closed rectal defect group. Short-term complications were 18.8% with no significant difference between the two groups. Most of the defects were well healed upon endoscopic follow-up; more unhealed/sinus formation was noticed in the open group (p = 0.01); more strictures were encountered in the closed group (p = 0.04). Overall, there was a significant difference in pre and post TEMS FISI scores in all three groups (p &lt; 0.00001, p &lt; 0.00001, p = 0.02). Comparing the open and closed defect groups, there was no difference in the functional outcome of patients in those who developed sinus or stricture but a significant difference in those with healed scar, with those in closed rectal defect group with worsening function (p = 0.02) Conclusion Both the approaches of rectal defect management are associated with pros and cons. Long term complications should be expected and actively followed up for. Patients should be thoroughly counselled about these and possible deterioration in continence post-TEMS

Maruyoshi-Song flows and defect groups of $$ {\mathrm{D}}_{\mathrm{p}}^{\mathrm{b}} $$(G) theories

We study the defect groups of $$ {D}_p^b $$ D p b (G) theories using geometric engineering and BPS quivers. In the simple case when b = h∨(G), we use the BPS quivers of the theory to see that the defect group is compatible with a known Maruyoshi-Song flow. To extend to the case where b ≠ h∨(G), we use a similar Maruyoshi-Song flow to conjecture that the defect groups of $$ {D}_p^b $$ D p b (G) theories are given by those of G(b)[k] theories. In the cases of G = An, E6, E8 we cross check our result by calculating the BPS quivers of the G(b)[k] theories and looking at the cokernel of their intersection matrix.

Optimization of Ligature/Bone Defect-Induced Periodontitis Model in Rats

Background The destruction of alveolar bone is a crucial manifestation of severe periodontitis, which stem cell-based bioengineered therapies are expected to cure. Therefore, a cost-effective, reproducible, quantifiability and easier-to-administrate animal model that mimics human periodontitis is of great importance for further endeavor. Methods In this study, we created periodontitis rat models in silk ligation group, bone defect group and bone defect/silk ligation group respectively. he clinical indexes of periodontitis were observed and recorded. The mandible was taken for micro-computed tomographic, histological and histomorphometric analysis to assess the periodontal inflammation and bone remodeling Results Obvious periodontal inflammation but slight alveolar bone resorption were observed in the ligation group, while surgical trauma was not robust enough to continually worsen the constructed bone defect area in the bone defect group. In the bone defect/ligature group, obvious and stable periodontal inflammation could be the most lasting with similar evolving pathological patterns of human periodontitis. It also exhibited enhanced clinical similarity and confirmed its superiority in quantitativeness. Conclusions The present rat model is the first study to reproduce a pathological process similar to human periodontitis with reliable stability and repeatability, manifesting a priority to previous methods. Day 9 to Day 12 is the best time for reproducing severe periodontitis syndromes with vertical bone resorption in this model.

Type I collagen scaffold with WNT5A plasmid for in situ cartilage tissue engineering

BACKGROUND: Cartilage tissue lacks the ability to heal. Cartilage tissue engineering using cell-free scaffolds has been increasingly used in recent years. OBJECTIVE: This study describes the use of a type I collagen scaffold combined with WNT5A plasmid to promote chondrocyte proliferation and differentiation in a rabbit osteochondral defect model. METHODS: Type I collagen was extracted and fabricated into a collagen scaffold. To improve gene transfection efficiency, a cationic chitosan derivative N,N,N-trimethyl chitosan chloride (TMC) vector was used. A solution of TMC/WNT5A complexes was adsorbed to the collagen scaffold to prepare a WNT5A scaffold. Osteochondral defects were created in the femoral condyles of rabbits. The rabbits were divided into defect, scaffold, and scaffold with WNT5A groups. At 6 and 12 weeks after creation of the osteochondral defects, samples were collected from all groups for macroscopic observation and gene expression analysis. RESULTS: Samples from the defect group exhibited incomplete cartilage repair, while those from the scaffold and scaffold with WNT5A groups exhibited “preliminary cartilage” covering the defect. Cartilage regeneration was superior in the scaffold with WNT5A group compared to the scaffold group. Safranin O staining revealed more proteoglycans in the scaffold and scaffold with WNT5A groups compared to the defect group. The expression levels of aggrecan, collagen type II, and SOX9 genes were significantly higher in the scaffold with WNT5A group compared to the other two groups. CONCLUSIONS: Type I collagen scaffold showed effective adsorption and guided the three-dimensional arrangement of stem cells. WNT5A plasmid promoted cartilage repair by stimulating the expression of aggrecan, type II collagen, and SOX9 genes and proteins, as well as inhibiting cartilage hypertrophy.

Investigation of the relationship between trochlear morphology and medial patellar cartilage defect using magnetic resonance imaging

The aim of this study was to evaluate trochlear morphology in patients with medial patellar cartilage defects via magnetic resonance imaging (MRI). Three hundred patients who were diagnosed with grade 2, 3 and 4 medial patellar cartilage defect using MRI according to the International Cartilage Repair Society Classification System and 100 control subjects were evaluated. Trochlear morphology was evaluated based on lateral trochlear inclination (LTI), medial trochlear inclination (MTI), sulcus angle( SA), femoral lateral and medial condyle symmetry, trochlear facet asymmetry, and trochlear width on the axial MR images. The mean SA was significantly higher in the medial patellar cartilage defect group compared to the control group (p<.05). The LTI and MTI of the cartilage defect group were significantly lower than those of the control group (p<.05). With the decreasing LTI and MTI, there was an increase in medial patellar cartilage loss. LTI (r=-0.46) and MTI (r=-0.53) were moderately correlated with SA. There was no significant differences in femoral lateral and medial condyle symmetry, trochlear facet asymmetry, and trochlear width between groups with and without medial patellar cartilge defect (p > .05). A flattened medial trochlea is a risk factor for cartilage structural damage of the medial patellofemoral joint, and it plays a role in the development of a defect in the medial patellar cartilage. The medial patellar cartilage defect is associated with the flattened lateral trochlea.

Ultrapurified Alginate Gel Containing Bone Marrow Aspirate Concentrate Enhances Cartilage and Bone Regeneration on Osteochondral Defects in a Rabbit Model

Background: Ultrapurified alginate (UPAL) gel implantation has been demonstrated as effective in cartilage repair for osteochondral defects; however, cell transplantation within UPAL gels would be required to treat larger defects. Hypothesis: The combination of UPAL gel and bone marrow aspirate concentrate (BMAC) would enhance cartilage repair and subchondral bone repair for large osteochondral defects. Study Design: Controlled laboratory study. Methods: A total of 104 osteochondral defects (1 defect per knee) of 52 rabbits were randomly divided into 4 groups (26 defects per group): defects without any treatment (Defect group), defects treated using UPAL gel alone (UPAL group), defects treated using UPAL gel containing allogenic bone marrow mesenchymal stromal cells (UPAL-MSC group), and defects treated using UPAL gel containing BMAC (UPAL-BMAC group). At 4 and 16 weeks postoperatively, macroscopic and histologic evaluations and measurements of repaired subchondral bone volumes of reparative tissues were performed. Collagen orientation and mechanical properties of the reparative tissue were assessed at 16 weeks. Results: The defects in the UPAL-BMAC group were repaired with hyaline-like cartilage with well-organized collagen structures. The histologic scores at 4 weeks were significantly higher in the UPAL-BMAC group (16.9 ± 2.0) than in the Defect group (4.7 ± 1.9; P < .05), the UPAL group (10.0 ± 3.3; P < .05), and the UPAL-MSC group (12.2 ± 2.9; P < .05). At 16 weeks, the score in the UPAL-BMAC group (24.4 ± 1.7) was significantly higher than those in the Defect group (9.0 ± 3.7; P < .05), the UPAL group (14.2 ± 3.9; P < .05), and the UPAL-MSC group (16.3 ± 3.6; P < .05). At 4 and 16 weeks, the macroscopic evaluations were significantly superior in the UPAL-BMAC group compared with the other groups, and the values of repaired subchondral bone volumes in the UPAL-BMAC group were significantly higher than those in the Defect and UPAL groups. The mechanical properties of the reparative tissues were significantly better in the UPAL-BMAC group than in the other groups. Conclusion: The implantation of UPAL gel containing BMAC-enhanced hyaline-like cartilage repair and subchondral bone repair of osteochondral defects in a rabbit knee model. Clinical Relevance: These data support the potential clinical application of 1-step treatment for large osteochondral defects using biomaterial implantation with cell transplantation.

ALLOGRAFT BONE APPLICATION IN THE RAT CALVARIAL BONE DEFECT MODEL: A HISTOPATHOLOGICAL STUDY

Trauma, neoplasms, infections, and congenital anomalies may be the reason for the calvarial bone defects. For eliminating bone defects in the cranial region to stimulate bone regeneration different graft types have been tried. In our study, we aimed to investigate the effects of allograft application in the rat calvarial bone defect model. For this purpose, 14 Wistar male rats were determined; defect (n=7) and defect + graft (n=7) groups. . The frontal bone was opened and a circular full thickness bone defect (5 mm) was created in the midline. Allograft material was placed in the defect area. All animals were sacriced after 28 days and the calvarial bones were followed up for routine histologic preparations. Sections were stained with H-E and scoring for histopathological parameters (inammation, brosis, osteoclast number, osteoblast number, osteocyte number, matrix formation, new bone trabecular diameter). In our study, inammation, brosis and osteoclast numbers decreased in the defect + graft group compared to the defect group, and osteocyte, osteoblast, matrix formation and bone trabecular diameter has increased signicantly. Histopathological evaluation revealed scar tissue, increased mononuclear cell inltration, and necrosis in the defect group. In the defect + graft group, an increase in collagen ber, a decrease in inammatory cells, an increase in osteoblast cells and bone matrix were observed. As a result, allograft application has been found to support new bone formation in the calvarial defect model by creating an osteoinductive and osteoconductive effect.