Bursal acromial resurfacing improves shoulder biomechanics in a cadaveric model of massive rotator cuff tear.

PURPOSE: To investigate the effectiveness of bursal acromial resurfacing (acromiograft) on acromiohumeral distance, subacromial contact area, and pressure in a cadaveric model of massive rotator cuff tear. METHODS: Eight fresh-frozen cadaveric shoulders were tested using a customized shoulder testing system. Humeral head translation, subacromial contact pressure, and the subacromial contact area were evaluated across four conditions: (1) intact shoulder; (2) simulated massive rotator cuff tear; (3) 3-mm acromiograft condition; (4) 6-mm acromiograft condition. The acromiografts were simulated using Teflon and a reported technique. The values were measured at 0°, 20°, and 40° abduction and 0°, 30°, 60°, and 90° external rotation (ER) for each abduction status. RESULTS: Compared with a massive cuff tear, the 6-mm acromiograft significantly reduced the superior translation of the humeral head at all abduction/ER angles (P<0.05). The 3-mm acromiograft also decreased superior translation of the humeral head compared to massive cuff tear, but not all differences were significant. The 3- and 6-mm acromiografts significantly decreased the subacromial contact pressure and increased the subacromial contact area in almost all positions (P<0.05). The 3-mm acromiograft maintained biomechanical properties similar to the intact condition, whereas the 6-mm acromiograft increased the contact area. CONCLUSIONS: This biomechanical study demonstrated that both 3- and 6- mm acromiografts using Teflon in a cadaveric model of a massive cuff tear resulted in recentering of the superiorly migrated humeral head, increased the subacromial contact area, and decreased the subacromial contact pressure. The 3- mm graft was sufficient for achieving the intended therapeutic effects. CLINICAL RELEVANCE: The acromiograft can normalize altered biomechanics and may aid the treatment of massive cuff tears. As grafting the acromion's undersurface is new with limited clinical outcomes, further observation is crucial. Using Teflon instead of ADM allograft for bursal acromial resurfacing could yield different results, requiring careful interpretation.

Varus-valgus alignment of humeral short stem in reverse total shoulder arthroplasty: does it really matter?

BACKGROUND: The utilization of short humeral stems in reverse total shoulder arthroplasty has gained attention in recent times. However, concerns regarding the risk of misalignment during implant insertion are associated with their use. METHODS: Eight fresh-frozen cadaveric shoulders were prepared for dissection and biomechanical testing. A bespoke humeral implant was fabricated to facilitate assessment of neutral, varus, and valgus alignments using a single stem, and 10° was established as the maximum permissible angle for misalignments. Shift in humerus position and changes in deltoid length attributable to misalignments relative to the neutral position were evaluated using a Microscribe 3DLx system. The impingement-free range of motion, encompassing abduction, adduction, internal rotation, and external rotation (ER), was gauged using a digital goniometer. The capacity for abduction was evaluated at maximal abduction angles under successive loading on the middle deltoid. A specialized traction system coupled with a force transducer was employed to measure anterior dislocation forces. RESULTS: Relative to the neutral alignment, valgus alignment resulted in a more distal (10.5 ± 2.4 mm) and medial (8.3 ± 2.2 mm) translation of the humeral component, whereas the varus alignment resulted in the humerus shifting more superiorly (11.2 ± 1.3 mm) and laterally (9.9 ± 0.9 mm) at 0° abduction. The valgus alignment exhibited the highest abduction angle than neutral alignment (86.2°, P < .001). Conversely, the varus alignment demonstrated significantly higher adduction (18.4 ± 7.4°, P < .001), internal rotation (68.9 ± 15.0°, P = .014), and ER (45.2 ± 10.5°, P = .002) at 0° abduction compared to the neutral alignments. Anterior dislocation forces were considerably lower (23.8 N) in the varus group compared to the neutral group at 0°ER (P = .047). Additionally, abduction capability was markedly higher in varus alignment at low deltoid loads than the neutral alignment (5N, P = .009; 7.5 N, P = .007). CONCLUSIONS: The varus position enhances rotational range of motion (ROM) but increases instability, while the valgus position does not significantly impact ROM or instability compared to the neutral position.

Obesity and high myopia in children and adolescents: Korea National Health and Nutrition Examination Survey.

PURPOSE: The prevalence of both obesity and myopia are increasing in Korean children and adolescents. The purpose of this study is to examine the impact of obesity on the prevalence of myopia in Korean children and adolescents. METHODS: This study used the data of a nationally representative cross-sectional survey, the Korea National Health and Nutrition Examination Survey (KNHANES) VII conducted from 2016 to 2018. Of the 1237 children and adolescents aged 5-18 years who participated in the KNHANES VII and underwent ophthalmologic examinations for the survey, 1114 were selected for review, excluding those whose data on refractive error, family history of myopia, or waist circumference were missing. Body mass index (BMI) was classified into four groups: underweight (< 5th percentile), normal weight (≥ 5th percentile, < 85th percentile), overweight (≥ 85th percentile, < 95th percentile), and obese (≥ 95th percentile). Myopia was defined by the level of refractive error ≤ -0.5 diopters (D) and classified as mild (≤ -0.5 D, > -3.0 D), moderate (≤ -3.0 D, > -6.0 D), or high (≤ -6.0 D) myopia. The relationship between BMI and myopia was analyzed using complex sample logistic regression. Age and family history were corrected followed by an analysis of the odds ratios. RESULTS: Compared to those with normal weights (controls), being underweight, overweight, or obese showed no significant odds of developing mild and moderate myopia. Conversely, when compared with that of controls, the odds ratio of developing high myopia in the underweight, overweight, and obese groups was 0.77 (95% CI, 0.22-2.65), 1.37 (95% CI, 0.51-3.66), and 3.77 (95% CI, 1.98-7.16), respectively. Furthermore, in a separate analysis by sex and BMI, the odds ratio of developing high myopia was 2.84 (95% CI, 1.10-7.35) in boys with obesity and 4.23 (95% CI,1.19-15.09) and 5.04 (95% CI,1.77-14.34) in overweight and obese girls, respectively. CONCLUSIONS: An association exists between obesity in childhood and adolescence and high myopia. Being overweight in girls was also found to be associated with high myopia. Thus, efforts to maintain a healthy weight during childhood and adolescence are of great importance.

Association of bone mineral density with the development of knee osteoarthritis in men and women: a cross-sectional study using the fourth and fifth Korea National Health and Nutrition Examination Surveys.

Bone mineral density (BMD) and osteoarthritis (OA) were correlated but the relationship was varied according to sex. An association between lumbar spine and femur neck BMDs and OA showed a positive relation in women, while lumbar spine and pelvis BMDs in men were associated with OA with a negative relation. PURPOSE: The purpose of this study was to evaluate the association of BMD in various body parts in conjunction with the presence or severity of radiographic knee osteoarthritis (KOA) in relation to sex. METHODS: This study was a cross-sectional analysis using Korea National Health and Nutrition Examination Surveys. KOA was graded using the Kellgren-Lawrence (KL) grading system. Radiographic KOA was defined as a KL grade 2 or higher. The associations between KOA and BMD in certain body parts (femur, pelvis, lumbar, lower leg, and whole-body) were assessed. BMD was measured using dual-energy X-ray absorptiometry. The BMD of each body part was divided into quartiles and the relationship between KOA and BMD was examined according to sex. RESULTS: BMD did not show a significant tendency according to KL grade in either sex. In men, the severity of KL grade have a statistically significant relationship with total femur (R2 = 0.303, p < 0.05), femur neck (R2 = 0.257, p < 0.05), lumbar (R2 = 0.137, p < 0.05), and pelvis BMD (R2 = 0.185, p < 0.05). In women, total femur (R2 = 0.466, p < 0.05), lumbar (R2 = 0.316, p < 0.05), pelvis (R2 = 0.343, p < 0.05), and lower leg BMD (R2 = 0.133, p < 0.05) were associated with the severity of KL grade. When the BMD was divided into quartiles, lumbar (p < 0.05) and pelvis BMD (p < 0.05) in men had statistically significant association with knee OA as BMD decreased. In women, femur neck (p < 0.05) and lumbar BMD (p < 0.05) were significantly associated with knee OA as BMD increased. CONCLUSION: The relationship between BMD and OA severity varied according to sex. In women, there was a positive association between femur neck and lumbar BMD and OA, while BMD of the lumbar and pelvis in men was negatively correlated with OA. LEVEL OF EVIDENCE: Cohort study, III.

Effect of triamcinolone acetonide on stiffness after surgical treatment of proximal humerus fractures: a randomized controlled study.

INTRODUCTION: The primary aim of this study was to determine the effectiveness and safety of an intraarticular triamcinolone injection for the treatment of stiffness after the operative treatment of proximal humerus fractures. MATERIALS AND METHODS: 88 patients who underwent plate fixation for proximal humerus fractures were enrolled. The patients were randomly divided into two groups, with Group I receiving a glenohumeral injection of triamcinolone 8 weeks postoperatively and Group II receiving no injection postoperatively. Outcomes were measured and compared based on the range of motion (ROM) and functional scores. Follow-up outcomes were assessed at initial, 3, 6 and 12 months postoperatively and at the last follow-up. Shoulder trauma series were taken at every visit to evaluate the fracture healing. The mean follow-up period was 25.37 (± 3.85) months Group I and 24.24 (± 6.23) months for group II. RESULTS: In both groups, the final outcome of the ROM and functional outcome was significantly better at last F/U than at postoperative 8 weeks. Group I had significantly better results than Group II at postoperative 3 and 6 month in terms of forward flexion, external rotation, and VAS for pain. Also, Group I showed better performance in terms of ASES and Constant score at postoperative 3 months. The fracture union rate did not differ between Groups I and II. CONCLUSIONS: Postoperative glenohumeral injection of triamcinolone is a safe and effective treatment modality for shoulder stiffness after internal fixation of proximal humerus fractures during the early period of rehabilitation.

An updated review of mucosal melanoma: Survival meta-analysis.

Mucosal melanoma (MM) is a highly lethal variant of melanoma that carries a poor prognosis. Extremely low incidence and survival rates have led to few clinical trials, and a lack of protocols and guidelines. The present study performed a survival meta-analysis for the quantitative synthesis of available evidence to search for key patterns that would help clinicians tailor optimal therapeutic strategies in MM. PubMed, EMBASE, Cochrane, MEDLINE, Google Scholar and other databases were searched. Hazard ratios, in disease-specific and overall survival, were calculated for each of the survival-determining variables. MM was 2.25 times more lethal than cutaneous melanoma (CM). The most significant threats to survival were advanced Tumor-Node-Metastasis stage, sino-nasal location, and old age. Chemotherapy was the most effective form of adjuvant therapy. Disease-specific survival, the primary measure of the effect sizes, can fluctuate depending on the accuracy of the reported cause of mortality. In conclusion, MM is a peculiar type of melanoma, with clinical and molecular profile vastly different from the much-familiar CM. In the wake of the era of precision oncology, further studies on driver mutations and oncogenic pathways would likely lead to improved patient survival.

Syringocystadenocarcinoma Papilliferum: A Case Report and Review of the Literature.

Syringocystadenocarcinoma papilliferum (SCACP) is a rare malignant adnexal neoplasm, which is considered as a malignant counterpart of syringocystadenoma papilliferum (SCAP). Clinically, SCACP appears as a nodule, inflammatory plaque, or tumor. The lesion is usually covered with crusts, which are formed by secretion of the apocrine epithelial cells. Histologically, SCACP resembles SCAP, with cystic papillomatous invaginations connected to the skin surface by funnel-shaped structures lined by infundibular epithelium. The stroma of the tumor consists of a dense inflammatory infiltrate of plasma cells and lymphocytes. SCACP differs from SCAP in terms of the architectural and cytological features of the tumor cells, and is characterized by higher nuclear cytoplasmic ratio, nuclear irregularity, coarse chromatin, and increased mitotic activity. However, the immunohistochemical findings of SCACP vary. Since only 49 cases of SCACP have been reported in the English literature, the clinical and histologic characteristics of SCACP have not been fully established. Further studies on the diagnostic criteria for SCACP are warranted. Here, we report a rare case of SCACP and present a review of other relevant literature.

Increased human tumor necrosis factor-α levels induce procoagulant change in porcine endothelial cells in vitro.

BACKGROUND: Intravascular thrombosis and systemic coagulation abnormalities are major hurdles to successful xenotransplantation and are signs of acute humoral rejection. Increased expression of tissue factor (TF) is associated with the development of microvascular thrombosis in xenografts. To develop an effective strategy to prevent accelerated coagulation in xenografts, we investigated the mechanism by which porcine endothelial cells (PECs) become procoagulant after contact with human blood. METHODS: The changes in TF mRNA levels and activity in PECs after incubation with 20% human serum or human bioactive molecules, including C5a, tumor necrosis factor-α (TNFα) and interleukin (IL)-1α, were evaluated using real-time PCR and the factor Xa chromogenic assay, respectively. The procoagulant changes in PECs by these agonists were evaluated by measuring the coagulation time of human citrated plasma suspended with PECs pretreated with each agonist. TF expression and coagulation times were also assessed in PECs transfected with short interfering RNA (siRNA) designed to knock down porcine TF. We also examined the production of proinflammatory cytokines in human whole-blood or plasma after contact with PECs, which were screened using the cytometric bead array system. TNFα levels were measured using ELISA in whole-blood after contact with PECs, with or without the addition of xenoreactive antibodies or C1 esterase inhibitor. RESULTS: Porcine TF mRNA and activity in PECs were up-regulated in response to human TNFα and IL-1α but were not affected by C5a or 20% human serum. Up-regulation of TF expression by human TNFα or IL-1α shortened PEC-induced coagulation time, while siRNA-mediated knockdown of TF expression prolonged coagulation time. The incubation of PECs with human whole-blood led to a significant increase in human TNFα levels in the blood, which was promoted by the addition of xenoreactive antibodies and prevented by C1 esterase inhibitor. CONCLUSIONS: Human TNFα level increases in human blood after contact with PECs, which is attributed to xenoreactive antibody binding and subsequent complement activation. Human TNFα induces procoagulant changes in PECs with increased TF expression. This study suggests that human TNFα may be one of the mediators linking complement activation with procoagulant changes in the xenoendothelium.

Graft rejection in the xenogeneic transplantation of mice: diagnosis with in vivo MR imaging using the homing trait of macrophages.

BACKGROUND: To evaluate the feasibility of magnetic resonance (MR) imaging to depict the in vivo recruitment of superparamagnetic iron oxide (SPIO)-labeled macrophages and to diagnose graft rejection in xenogeneic transplantation. METHODS: We transplanted the trachea of SD rat (xenogeneic) or C3H/HeN mouse (syngeneic) into the left thighs of six male C3H/HeN mice. The SPIO-labeled macrophage was administered through the tail vein 2 days (acute) or 14 days (chronic) after transplantation in each group. The left thighs of the mice were imaged on a 4.7-T MR scanner 24 h after macrophage administration. We evaluated the extent and pattern of the susceptibility effect (macrophage distribution) and compared them in the two groups. The MR findings were then correlated with the histopathologic results. We also measured in both groups the monocyte chemoattractant protein (MCP)-1 level before and 2 days, 2 weeks, and 4 weeks after transplantation. RESULTS: The band-shaped lower signal intensity (SI) zone was noted around the graft in the acute and chronic phases of xenogeneic group and in the acute phase of syngeneic group, but it was not noted in the chronic phase of syngeneic transplantation. The lower SI zone corresponded to the distribution of SPIO-labeled macrophages on histopathological analyses. On histologic examination, the severe inflammation developed around the xenogeneic graft, but only slightly around the syngeneic graft. MCP-1 was elevated 2 days after transplantation in both groups, but then gradually decreased in the syngeneic group; in xenogenic group, the MCP-1 value decreased by week 2 but then increased by week 4. CONCLUSIONS: This study demonstrates that the homing of intravenously administered SPIO-labeled macrophages can be monitored on MR imaging and is correlated with the MCP-1 level and the histopathologic findings of the xenograft rejection.

Pace of macrophage recruitment during different stages of soft tissue infection: semi-quantitative evaluation by in vivo magnetic resonance imaging.

We describe the pace of recruitment of iron-oxide-labeled macrophages to the site of different stages of infection by in vivo magnetic resonance (MR) imaging. Peritoneal macrophages were labeled with superparamagnetic iron oxide ex vivo and administered through the tail vein 6 (acute) or 48 (subacute) h after bacterial inoculation. The legs of the mice were imaged sequentially on a 4.7-T MR unit before and 3, 6, 12, 18, 24, 48 and 72 h after macrophage administration. The band-shaped lower signal intensity zone around the abscess on T2*-weighted GRE images became more obvious due to recruited macrophages up until 24 h after injection in the subacute and 48 h after injection in the acute group, indicating that the relative SI of the abscess wall decreased more rapidly and the pace of recruitment of macrophages was faster in the subacute than in the acute group. Chemokine antibody arrays of mouse sera detected increased concentration of granulocyte-colony-stimulating factor and tissue inhibitor of metalloproteinase-1 beginning at 12 h and increased interleukin-13 at 18 h. Monocyte chemoattractant protein-1 and macrophage-colony-stimulating factor began to increase at 96 h after infection. This difference in pace of recruitment may result from the release of chemokines.