Search

Purpose: To evaluate the retear rate after arthroscopic rotator cuff repair using a suture bridge (SB) technique for patients with full thickness rotator cuff tears and whether the non- healing cuff impaired the shoulder function.Methods: From January 2013 to January 2014, 92 patients in our institution underwent arthroscopic double-row suture bridge repair for the treatment of full-thickness rotator cuff tear 55 patients who have completed the 5 years follow-up were enrolled in this study. There were 36 female and 19 male patients, and the average age was 58.6 years (range, 41- 70 years). The tears were classified into small ( 5 cm) according to the classification of DeOrio and Cofield. According to the intraoperative measurement, small tears were found in 5 shoulders (9%), medium tears in 19 shoulders (34.5%), large tears in 23 shoulders (41.8%), and massive tears in 8 shoulders (14.5%). The mean follow-up was 71.2 months (range, 66-78 months). Post-operative cuff integrity was evaluated with ultrasound (US) according to the published literature which was comparable to Sugaya MRI classification. Types I-III indicated cuff healing and types IV or V indicated retear. The retear patterns were divided into type 1 (failure at the original repair site) or 2 (failure around the medial row). At baseline and final follow-up, shoulder functional outcomes were measured using validated, shoulder-specific outcome scores, including the Constant-Murley score (CS) and the American Shoulder and Elbow Score (ASES). The difference in abduction muscle strength was also evaluated between the integrity and the retear group.Results: At final follow-up, the rotator cuff was completely healed in 45 of the 55 shoulders. There were recurrent tears in 10 shoulders, and the retear rate was 18.2%. The type 1 re- tear pattern was found in 4 shoulders (40%), and type 2 in 6 shoulders (60%). The Constant and ASES scores improved from 41.00 to 92.00, and from 41.33 to 88.00, respectively. The mean differences in shoulder scaption strength between the healing and the retear group were 1.1±0.82Kg and 3.0±0.88Kg respectively. The difference in muscle strength between the retear and the healing group was statistically significant (pConclusion: Arthroscopic suture bridge repair of full-thickness rotator cuff tears led to excellent improvement in shoulder function, but maintained a high retear rate. Although the retear group had inferior muscle strength, the patients were still satisfied, and shoulder function was improved due to pain relief. Whether such changes in muscle strength impair patients' long-term quality of life and shoulder function remains to be discussed.Level of evidence IV

In this study, a systematic study on the characterization of two kinds of steelmaking sludges, oil-containing sludge (Sludge-I) and alkali-containing sludge (Sludge-II), were carried out by using X-ray fluorescence spectrometry (XRF), leaching toxicity test, X-ray diffraction (XRD), scanning electron microscopy (SEM), TG-DSC, and proximate analysis, and their potential of being recycled as alternative fuel and raw materials in cement production was also discussed. Results showed that Al2O3, Fe2O3, SiO2, and CaO were the major compositions in calcinated Sludge-I and Sludge-II after being calcinated at 850°C. The calorific values of Sludge-I and Sludge-II were 8513 J g−1 and 3299 J g−1 and the combustible contents were 62.22% and 34.03%, respectively. The content of alkalis in Sludge-I was lower than that in Sludge-II and both of these values were within the scope of requirement for cement. Considering the similar compositions as cement raw materials, high calorific values and combustible contents, both of the two sludges had potential of being recycled as alternative fuel and raw materials in cement production. But the higher heat and lower alkali content in Sludge-I made its potential better. The research would be helpful to understand the composition and thermal behavior of the sludges and to further develop more ideal utilization methods. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 957–961, 2016

The importance of the porous interfacial transition zone to the chemical aggression of concrete is obvious when one considers the relations existing between porosity, permeability, chemical composition and the sulfate attack. In this study, the effect of ITZ quantity through varying aggregate content on the deterioration of blended cement concrete under sulfate attack, was determined to understand better the relationship between sulfate ions and concrete microstructure. The ITZ quantity was directly proportional to the aggregate volume fraction. Therefore, the effect of ITZ on sulfate resistance ability of concrete made with pure OPC and blended binders was evaluated by a comparison among mortars with systematically varied aggregate volume fraction. The porosity distribution with the ITZ was determined by using a quantitative backscattered electron microscopy (BSE) image analysis. It was found that the incorporation of moderate amount of Limestone filler is able to compact the microstructure of both ITZ and bulk matrix by filling effect and nucleation sites effect. The effects of slag on the porosity of ITZ were dependent on the replacement rate. The degree of deterioration had a slight tendency to increase for the samples prepared with higher aggregate volume content, which means high ITZ volume fraction. For the sulfate to reach the interior of the samples, it must move through the bulk cement matrix. The effect of aggregate and ITZ can only be notable when the interior structure was exposed to the sulfate ions. The presence of ITZ was normally accompanied by a denser bulk cement matrix. This could limit the ingress of sulfate ions and delay the formation of expansive products in initial stage. After the sulfate penetrates into the interior of the samples, the inner structure was expected to exert more significant influences on the deterioration.

Applying blended materials with finer particle size or high reactivity could be an effective and economic way for improving the microsturcture of interfacial transition zone (ITZ). In this study, the porosity characteristics of ITZ in concrete made with OPC and blended binders were determined quantitatively by using backscattered electron microscopy (BSE) image analysis and mercury intrusion porosimetry (MIP) measurements. This paper especially focused on the effects of slag and limestone filler on the thickness and pore structure of the ITZ. Results indicated that the porosity at each distance reduces with increasing limestone filler from 0 to 5%, and a significant increase is observed in the sample with 10% of limestone filler. The addition of 5% of limestone filler is able to densify the pore structure of both ITZ and bulk matrix. The reduction in pore volume in the range coarser than 100 nm contributed to the largest decrease in the total pores. Increasing the incorporation level of limestone filler to 10% resulted in an increase in the total porosity. The influences of slag on the porosity characteristics were highly dependent on the replacement level and the determined pore size regions. The addition of 35% of slag reduces the porosity at all distances and produces a denser microstructure both in the ITZ and bulk cement matrix. However, this improvement disappears when the substitution amount reaches to 70%. The incorporation of slag as a partial substitute for Portland cement tends to refine the pore structure.