Fixation technique of biodegradable magnesium alloy suture anchor in the rotator cuff repair of the shoulder in a goat model: a technical note.

BACKGROUND: Shoulder disorders, particularly rotator cuff tears, are prevalent musculoskeletal conditions related to aging. Although the widely used suture anchor technique provides strong mechanical support to the tendon, it is associated with a risk of postoperative tendon retearing. The conventionally used titanium alloys can affect the interpretation of magnetic resonance imaging. Degradable magnesium alloys possess excellent biocompatibility, similar mechanical property to the bone, and stimulating bone formation ability from Mg2+. The purpose of this experiment was to develop innovative magnesium-based suture anchors to enhance rotator cuff repair by improving fixation materials, and to evaluate their feasibility in a goat model. METHODS: We developed fluoridized ZK60 suture anchors as the implantation material for two goats, who underwent rotator cuff repair surgery on both shoulders. Computed tomography (CT) and histological analysis were performed at 12 weeks postoperatively, and the results were compared between the magnesium and titanium alloy groups. Additionally, a hematological examination was conducted, which included assessments of red blood cells, white blood cells, platelets, coagulation function, liver function, kidney function, and magnesium ion concentration. RESULTS: The 12-week postoperative CT images showed intact MgF2 ZK60 suture anchors, effectively reconnecting the infraspinatus tendon to the humeral head. The anchors became less visible on CT scans, indicating absorption by surrounding tissues. New bone formation in the MgF2 group surpassed that in the Ti group, demonstrating superior osseointegration. The similarity between cortical bone and magnesium reduced stress-shielding and promoted bone regeneration. Histological analysis revealed successful tendon healing with MgF2 anchors, while the Ti group showed discontinuous interfaces and reduced collagen secretion. Hematological examination showed stable liver, renal function, and magnesium ion levels. CONCLUSIONS: The findings indicate that MgF2-coated suture anchors are feasible for rotator cuff repair and potentially other orthopedic applications. We hope that magnesium alloy anchors can become the solution for rotator cuff tendon repair surgery.

Association between the Severity of Nonalcoholic Fatty Liver Disease and the Risk of Coronary Artery Calcification.

Background and Objectives: There are limited data on the association between severity of non-alcoholic fatty liver disease (NAFLD) and coronary artery calcification. This study investigated sonographic diagnosed NAFLD and coronary artery calcium score (CAC) as detected by cardiac multidetector computed tomography in general populations. Materials and Methods: A total of 545 patients were enrolled in this study. NAFLD was diagnosed by ultrasonography examination and CAC score were evaluated by cardiac multidetector computed tomography. The association between NAFLD and artery calcium score stage was determined by logistic regression analysis and Spearman correlation coefficient analysis. Results: Of all the participants, 437 (80.2%) had ultrasonography-diagnosed NAFLD and 242 (44%) had coronary artery calcification (CAC > 0). After adjustment for cardiovascular risk factors, the risk of developing coronary artery calcification was 1.36-fold greater in the patients with different severity of NAFLD compared to those without NAFLD (OR = 1.36, 95% CI = 1.07-1.77, p = 0.016). The highest OR for separate coronary artery calcification was 1.98 (OR = 1.98, 95% CI = 1.37-2.87, p < 0.001) in the left main artery, and the risk was still 1.71-fold greater after adjustments (OR = 1.71, 95% CI = 1.16-2.54, p = 0.007). Conclusions: This cross-sectional study demonstrated that the severity of NAFLD was associated with the presence of significant coronary artery calcification, especially in the left main coronary artery, suggesting increasing the cardiovascular risk.

Operative treatment of chronic ulnar collateral ligament humeral origin avulsion fracture in young baseball players.

Chronic ulnar collateral ligament humeral origin avulsion fracture in young baseball players is a rare condition and a difficult problem to treat. Eight high school or college student baseball players with onset of symptoms in their adolescent ages were collected in this series. Their mean age at surgical intervention was 17.8 ± 1.99 years. The fracture was operated on with muscle splitting, ulnar nerve-sparing technique. Suture anchors were employed to fix the avulsed fragment. Visual analog scale, Mayo elbow performance score, and Conway scale were used for objective patient evaluation. The patients were followed up for 30.8 ± 10.2 months. Six patients have achieved solid bony union, and 2 had partial union. All patients showed no medial space widening on followed-up stress films. Visual Analogue Scale score improved from 9 to 0. The Mayo elbow performance score improved from 60 ± 10 to 85 ± 15 points pre- and post-operatively. The Conway scale had 3 excellent, 3 good, and 2 fair results. The average return to pitching occurred 7 months post-operatively at a rate of 75%. The present results indicate that open reduction and fixation with suture anchors is an effective treatment method for chronic ulnar collateral ligament humeral origin avulsion fracture in young baseball players.

Interference of Co-amplified nuclear mitochondrial DNA sequences on the determination of human mtDNA heteroplasmy by Using the SURVEYOR nuclease and the WAVE HS system.

High-sensitivity and high-throughput mutation detection techniques are useful for screening the homoplasmy or heteroplasmy status of mitochondrial DNA (mtDNA), but might be susceptible to interference from nuclear mitochondrial DNA sequences (NUMTs) co-amplified during polymerase chain reaction (PCR). In this study, we first evaluated the platform of SURVEYOR Nuclease digestion of heteroduplexed DNA followed by the detection of cleaved DNA by using the WAVE HS System (SN/WAVE-HS) for detecting human mtDNA variants and found that its performance was slightly better than that of denaturing high-performance liquid chromatography (DHPLC). The potential interference from co-amplified NUMTs on screening mtDNA heteroplasmy when using these 2 highly sensitive techniques was further examined by using 2 published primer sets containing a total of 65 primer pairs, which were originally designed to be used with one of the 2 techniques. We confirmed that 24 primer pairs could amplify NUMTs by conducting bioinformatic analysis and PCR with the DNA from 143B-ρ0 cells. Using mtDNA extracted from the mitochondria of human 143B cells and a cybrid line with the nuclear background of 143B-ρ0 cells, we demonstrated that NUMTs could affect the patterns of chromatograms for cell DNA during SN-WAVE/HS analysis of mtDNA, leading to incorrect judgment of mtDNA homoplasmy or heteroplasmy status. However, we observed such interference only in 2 of 24 primer pairs selected, and did not observe such effects during DHPLC analysis. These results indicate that NUMTs can affect the screening of low-level mtDNA variants, but it might not be predicted by bioinformatic analysis or the amplification of DNA from 143B-ρ0 cells. Therefore, using purified mtDNA from cultured cells with proven purity to evaluate the effects of NUMTs from a primer pair on mtDNA detection by using PCR-based high-sensitivity methods prior to the use of a primer pair in real studies would be a more practical strategy.

Advantages and considerations in the confirmation of mitochondrial DNA mutations by denaturing HPLC and pyrosequencing.

Human mitochondrial DNA (mtDNA) encodes 13 polypeptides essential for oxidative phosphorylation. Because of the unique features of "replicative segregation" and "threshold expression" of mtDNA genetics, identification of homoplasmy versus heteroplasmy status is critical. Results from various detection methods may lead to different interpretations on formation or outcome of mtDNA mutations, such as the conclusion of somatic mutation versus genetic drift in cancers. Denaturing high-performance liquid chromatography (DHPLC) and pyrosequencing (PSQ) have recently been employed to confirm the presence of heteroplasmy of mtDNA because of their high sensitivity in detecting heteroplasmic mutations compared with direct sequencing. Moreover, PSQ has superior ability in quantifying percentage of heteroplasmy. However, there could be disagreement between these two techniques and several issues specific for mtDNA should be taken into consideration. Particularly, DHPLC analysis should be more prone to be interfered by nuclear mitochondrial sequences (Numts), if it is coamplified with mtDNA, than PSQ analysis.