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Objectives. The objectives of this study were to identify the risk factors and incidence of anterior bone loss (ABL) after Baguera C cervical disc arthroplasty (CDA) and identify whether design differences in artificial discs affect ABL. Methods. In this retrospective radiological review of patients who underwent single-level Baguera C CDA in a medical center, the extent of ABL and the following radiological parameters were recorded: global and segmental alignment angle, lordotic angle (or functional spinal unit angle), shell angle, global range of motion (ROM), and ROM of the index level. ABL at the index level was grade 0-2. Grade 0 was defined as no remodeling, grade 1 as spur disappearance or mild change in body contour, and grade 2 as obvious bone regression with Baguera C Disc exposure. Results. Combining grade 1 and grade 2, ABL was found in 56 upper adjacent vertebrae and 52 lower adjacent vertebrae of the 77 patients. Only 18 patients (23.4%) had no ABL. Shell angle differed significantly between ABL grades of both the upper and lower adjacent level: 0.0° in grade 0 and 1 ABL vs. 2.0° in grade 2 ABL of the upper adjacent level (p < 0.05); and 0.0° in grade 0 and 1 ABL vs. 3.5° in grade 2 ABL of the lower adjacent level (p < 0.05). A female predominance of ABL was found. Hybrid surgery and artificial disc size were also related to ABL. Conclusions. ABL is more common in Baguera C Disc arthroplasty than Bryan Disc arthroplasty. Larger shell angle was related to ABL after CDA with Baguera C Discs, which may indicate that shell angle is pivotal in determining the incidence of ABL after CDA. Females had more ABL with Baguera C Disc arthroplasty; this might be related to shorter endplate lengths as well as a smaller endplate-implant mismatch. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is characterized by degradation of the cartilage matrix, leading to pathologic changes in the joints. However, the pathogenic effects of synovial tissue inflammation on OA knees are not clear. To investigate whether the inflammation caused by the medial plica is involved in the pathogenesis of osteoarthritis, we examined the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), interleukin (IL)-1β, and tumor necrosis factor (TNF)-α in the medial plica and pannus-like tissue in the knees of patients with medial compartment OA who underwent either arthroscopic medial release (stage II; 15 knee joints from 15 patients) or total knee replacement (stage IV; 18 knee joints from 18 patients). MMP-2, MMP-3, MMP-9, IL-1β, and TNF-α mRNA and protein levels measured, respectively, by quantitative real-time PCR and Quantibody human MMP arrays, were highly expressed in extracts of medial plica and pannus-like tissue from stage IV knee joints. Immunohistochemical staining also demonstrated high expression of MMP-2, MMP-3, and MMP-9 in plica and pannus-like tissue of stage IV OA knees and not in normal cartilage. Some TIMP/MMP ratios decreased significantly in both medial plica and pannus-like tissue as disease progressed from stage II to stage IV. Furthermore, the migration of cells from the pannus-like tissue was enhanced by IL-1β, while plica cell migration was enhanced by TNF-α. The results suggest that medial plica and pannus-like tissue may be involved in the process of cartilage degradation in medial compartment OA of the knee. [ABSTRACT FROM AUTHOR]

Background Context: Cervical disc arthroplasty (CDA) is an innovative procedure launched in the early 2000s. Compared with anterior cervical discectomy and fusion, many studies show that CDA offers equivalent clinical outcomes while reducing secondary procedures and total cost.Purpose: We sought to determine the incidence of anterior bone loss after CDA and the related biomechanical effects.Study Design/ Setting: Retrospective chart review.Patient Sample: Patients who underwent CDA with one level Bryan Disc (Medtronic SofamorDanek, Memphis, TN, USA) at one institution.Outcome Measures: Radiological measurements, including the extent of anterior bone loss, global alignment angle, shell angle, lordotic angle, mean degree of angle of the endplate with the horizontal line, global range of motion (ROM) and ROM of the index level were recorded. The grading of anterior bone loss of the index level was defined as Grade 0, no remodeling; Grade 1, spur disappearance or mild change in body contour; Grade 2, obvious bone regression with Bryan Disc exposure.Methods: Anatomical measures and ROM were compared by grade of bone loss.Results: Of the 121 patients included in the study, anterior bone loss was found in 53 (43.8%) on the upper adjacent level and 54 (44.6%) on the lower adjacent level. Twenty-nine patients (23.9%) had anterior bone loss in both levels. The majority of cases had Grade 1 anterior bone loss. Grade 2 bone loss was noted in the upper adjacent vertebra in only 5 patients and in 4 patients in the lower adjacent vertebra. Age, sex, operative level, and hybrid surgery had no effect on anterior bone loss. Most radiological assessments, including global alignment angle, lordotic angle, mean degree of angle of the endplate with the horizontal line, global ROM, and ROM of the index level, showed no correlation to anterior bone loss. Shell angle was found to be different in groups with or without remodeling in the upper adjacent level: 5.0 degreesin the Grade 0 group and 7.0 degrees in the Grade 1-2 group, p<.05.Conclusions: Many more patients than predicted had anterior bone loss. Increasing the shell angle of the artificial disc may increase the incidence of anterior bone loss after CDA. Further study of the biomechanics following CDA should help clarify the mechanisms at work. [ABSTRACT FROM AUTHOR]

The aim of this study was to observe the behavior of the interfacial transition zone (ITZ) of high-performance concrete that was under curing in saturated lime water. From the Scanning Electron Microscope (SEM), it was found that the pores and hydration products at the ITZ, within 100 μm between the paste and aggregate, permuted each other during the early hydration stage, and then appeared as a large lump or strip. They gradually became irregular and small lumps for the further curing age. At the curing age of 56 days, the pores almost concentrated within an area of 0–15 μm from the aggregate edge. The hydration products were much denser with the increase in its distance from the aggregate edge. [Copyright &y& Elsevier]