Radiologic Comparison of Humeral Position according to the Implant Designs Following Reverse Shoulder Arthroplasty: Analysis between Medial Glenoid/Medial Humerus, Lateral Glenoid/Medial Humerus, and Medial Glenoid/Lateral Humerus Designs

BACKGROUND: The currently available reverse shoulder arthroplasty (RSA) designs can be classified into medial glenoid/medial humerus (MGMH), lateral glenoid/medial humerus (LGMH), and medial glenoid/lateral humerus (MGLH) prosthesis designs. The purpose of this study was to radiologically analyze the effect of different RSA designs on humeral position following RSA. METHODS: A total of 50 patients who underwent primary RSA were retrospectively analyzed. Among 50 patients, 33 patients (group A: MGMH) underwent RSA with Aequalis system (Wright, Inc, Bloomington, MN, USA), 6 (group B: LGMH) with Aequalis system using bony increased offset, and 11 (group C: MGLH) with Aequalis Ascend Flex system. The acromiohumeral distance, acromioepiphyseal distance (AED), lateral humeral offset (LHO), LHO from the center of rotation (LHO(COR)), and deltoid length were radiologically measured to quantify the distalization and lateralization of the humerus. RESULTS: The increment in postoperative AED was 19.92 ± 3.93 mm in group A, 24.52 ± 5.25 mm in group B, and 25.97 ± 5.29 mm in group C, respectively (p=0.001). The increment in postoperative LHO was 0.13 ± 6.30 mm, 8.00 ± 12.14 mm, and 7.42 ± 6.88 mm, respectively (p=0.005). The increment in postoperative LHOCOR was 20.76 ± 6.06 mm, 22.04 ± 5.15 mm, and 28.11 ± 4.14 mm, respectively (p=0.002). CONCLUSIONS: The radiologic analysis of the effect of different RSA designs on humeral position following RSA showed significant differences in the increment in postoperative AED, LHO, and LHO(COR) between the 3 groups. Therefore, MGLH design seems to be more effective for humeral distalization and lateralization compared to original Grammont design.

Factors increasing the risk for psychosocial stress among Korean adults living in rural areas: using generalized estimating equations and mixed models

BACKGROUND: This study was conducted to analyze the distribution of the psychosocial well-being index among adults living in two rural communities in Korea and to examine its correlation with lifestyle variables such as sleep duration, regular exercise, and sedentary time. METHODS: Using the cohort data of the Atherosclerosis Risk of a Rural Area Korean General Population, this study examined 3631 participants living in Wonju and Pyeongchang in Gangwon Province; their preliminary data were established from 2005 to 2007 while their follow-up data were collected 3 years later. This study investigated demographic characteristics, lifestyle habits, disease history, Psychosocial Well-being Index-Short Form (PWI-SF) scores, sleep duration, regular exercise, and sedentary time during work. Using repeated measures ANOVA, this study examined how the variables and PWI-SF scores changed over the course of 3 years and identified the correlation between them based on mixed model analysis. Afterwards, using the generalized estimation equation, this study identified each variable's risk towards the PWI-SF high-risk group and performed a stratified analysis by occupation after dividing the participants into farmers and non-farmers. RESULTS: The PWI-SF high-risk group was found to be 18.9% of the participants from preliminary data and 15.5% from follow-up data. The odds ratio towards the PWI-SF high-risk group was 1.503 (95% CI 1.241–1.821) in the short sleep duration group and 1.327 (95% CI 1.136–1.550) in the non-regular exercise group. A stratified analysis by occupation showed that middle and long sedentary time in the white-collar group increased the risk toward the PWI-SF high-risk group. CONCLUSIONS: Short sleep duration, no regular exercise, and long sedentary time in the white-collar group were identified as risk factors toward the PWI-SF high-risk group in the rural communities, and policy interventions are needed to address this issue.

Dissociation of Polyethylene Liner of the Dual Mobility Acetabular Component after Closed Reduction of Dislocation: A Case Report / 대한고관절학회지

A dual mobility acetabular component has a structure that combines a polyethylene liner and a femoral head, unlike the general design of acetabular cups, making the dissociation of a polyethylene liner highly unlikely. In addition, it increases the range of motion and reduces the possibility of dislocations by increasing a jump distance. A fifty-one-year-old male who had received total hip arthroplasty with the dual mobility acetabular component visited a hospital for a posterior hip dislocation 10 weeks after the operation. At the emergency room, closed reduction was performed and the dislocation was reduced. However, plain imaging test revealed polyethylene liner dissociation after the closed reduction. Revision surgery was performed. We will report a rare case of early dislocation of the dual mobility acetabular component and dissociation of polyethylene liner accompanied with a literature review.

Clinical and Structural Outcomes of Arthroscopic Intraarticular Knotless Fixation for Upper Subscapularis Tendon Tears: A Preliminary Report

BACKGROUND: A novel technique for the repair of tears of the upper subscapularis tendon—intraarticular knotless fixation—has been introduced recently. The purpose of this study was to evaluate the clinical and structural outcomes of arthroscopic intraarticular knotless fixation for the treatment of upper subscapularis tendon tears. METHODS: We retrospectively analyzed the clinical and radiological outcomes of 27 patients who underwent arthroscopic intraarticular knotless fixation for upper subscapularis tendon tears. Finally, a total of 10 patients who could participate in at least a 6 month follow-up of magnetic resonance imaging evaluation and in a least 1-year follow-up on an outpatient basis were enrolled in our study. The mean age at the time of operation was 60.7 years, and the mean duration of follow-up was 14.7 months. Two patients had concomitant tears of the supraspinatus tendon and 8 patients had concomitant tears of the supraspinatus and the infraspinatus tendons. RESULTS: The clinical and radiological outcomes improved after the patients had undertaken arthroscopic intraarticular knotless fixation. The mean visual analogue scale score for pain during motion improved from 6.7 preoperatively to 1.4 at the final follow-up (p<0.001). The mean Constant score improved from 59.3 preoperatively to 79.6 at the final follow-up, and the mean the University of California at Los Angeles score, from 21.7 to 30.2, respectively (p<0.001 and p<0.001). The upper subscapularis tendon tear was healed in every patient except one (90%), for the patient had suffered from a postoperative trauma that resulted in a retear. CONCLUSIONS: We found that arthroscopic intraarticular knotless fixation gives good clinical and structural outcomes for the repair of upper subscapularis tendon tears. Arthroscopic intraarticular knotless fixation provided such a reliable and efficient restoration of the subscapularis tendon footprint that we anticipate it will become a widely-used procedure for upper subscapularis tendon tears.

Clinical and Structural Outcomes of Arthroscopic Intraarticular Knotless Fixation for Upper Subscapularis Tendon Tears: A Preliminary Report

BACKGROUND: A novel technique for the repair of tears of the upper subscapularis tendon—intraarticular knotless fixation—has been introduced recently. The purpose of this study was to evaluate the clinical and structural outcomes of arthroscopic intraarticular knotless fixation for the treatment of upper subscapularis tendon tears. METHODS: We retrospectively analyzed the clinical and radiological outcomes of 27 patients who underwent arthroscopic intraarticular knotless fixation for upper subscapularis tendon tears. Finally, a total of 10 patients who could participate in at least a 6 month follow-up of magnetic resonance imaging evaluation and in a least 1-year follow-up on an outpatient basis were enrolled in our study. The mean age at the time of operation was 60.7 years, and the mean duration of follow-up was 14.7 months. Two patients had concomitant tears of the supraspinatus tendon and 8 patients had concomitant tears of the supraspinatus and the infraspinatus tendons. RESULTS: The clinical and radiological outcomes improved after the patients had undertaken arthroscopic intraarticular knotless fixation. The mean visual analogue scale score for pain during motion improved from 6.7 preoperatively to 1.4 at the final follow-up (p<0.001). The mean Constant score improved from 59.3 preoperatively to 79.6 at the final follow-up, and the mean the University of California at Los Angeles score, from 21.7 to 30.2, respectively (p<0.001 and p<0.001). The upper subscapularis tendon tear was healed in every patient except one (90%), for the patient had suffered from a postoperative trauma that resulted in a retear. CONCLUSIONS: We found that arthroscopic intraarticular knotless fixation gives good clinical and structural outcomes for the repair of upper subscapularis tendon tears. Arthroscopic intraarticular knotless fixation provided such a reliable and efficient restoration of the subscapularis tendon footprint that we anticipate it will become a widely-used procedure for upper subscapularis tendon tears.

Cloning and Phylogenetic Analysis of Chitin Synthase Genes from Tricholoma matsutake

Chitin synthases(UDP-N-acetyl-D-glucosamine: chitin 4-beta-N-acetyl-D-glucosaminyl transferase, EC 2.4.1.16) catalyze the synthesis of chitin from UDP-N-acetyl-D-glucosamine. Two zymogenic type of chitin synthase gene(TmCHS1 and TmCHS2) were amplified and its nucleotide sequences were determined. By the amino acid comparison and UPGMA tree grouping, TmChs1 and TmChs2 were classified as class II and class IV chitin synthases respectively. The class II type TmChs1 was grouped with others of Agaricales ectomycorrhizal mushroom. Additionally the phylogenetic tree was well adapted to Hymenomycete previously classified by morphological and physiological characteristics.