Anisotropy, Anatomical Region, and Additional Variables Influence Young's Modulus of Bone: A Systematic Review and Meta-Analysis.

The importance of finite element analysis (FEA) is growing in orthopedic research, especially in implant design. However, Young's modulus (E) values, one of the most fundamental parameters, can range across a wide scale. Therefore, our study aimed to identify factors influencing E values in human bone specimens. We report our systematic review and meta-analysis based on the recommendation of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline. We conducted the analysis on November 21, 2021. We included studies investigating healthy human bone specimens and reported on E values regarding demographic data, specimen characteristics, and measurement specifics. In addition, we included study types reporting individual specimen measurements. From the acquired data, we created a cohort in which we performed an exploratory data analysis that included the explanatory variables selected by random forest and regression trees methods, and the comparison of groups using independent samples Welch's t test. A total of 756 entries were included from 48 articles. Eleven different bones of the human body were included in these articles. The range of E values is between 0.008 and 33.7 GPa. The E values were most heavily influenced by the cortical or cancellous type of bone tested. Measuring method (compression, tension, bending, and nanoindentation), the anatomical region within a bone, the position of the bone within the skeleton, and the bone specimen size had a decreasing impact on the E values. Bone anisotropy, specimen condition, patient age, and sex were selected as important variables considering the value of E. On the basis of our results, E values of a bone change with bone characteristics, measurement techniques, and demographic variables. Therefore, the evaluation of FEA should be performed after the standardization of in vitro measurement protocol. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Obesity and Ankle Prosthesis Revision: A Systematic Review and Meta-analysis.

BACKGROUND: The increasing number of total ankle arthroplasties (TAAs) has led to growing evidence on the risk factors for complications after surgery. However, the role of obesity in this patient group has been the subject of much debate. Therefore, this systematic review aimed to investigate the evidence for untoward effects of obesity following TAA. METHODS: We conducted a comprehensive search on April 28, 2023, in MEDLINE (via PubMed), Embase, and CENTRAL. Eligible observational studies reported on the short- and long-term outcomes of primary TAA, comparing patients with and without obesity (defined as body mass index > 30). Using a random effects model, we calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs) from 2 by 2 tables (event and nonevent in the obese and nonobese primary TAA groups). RESULTS: Nine studies with 10 388 patients were eligible for inclusion in the meta-analysis. We found significantly higher odds of revision in the obese group compared to the nonobese group (OR = 1.68, CI: 1.44-1.95). However, the odds of overall perioperative complications (OR = 1.55, CI: 0.50-4.80) and wound complications (OR = 1.34, CI: 0.29-6.20) were nonsignificantly higher in the obese group. CONCLUSION: Based on our results, obesity may have affected long-term outcomes following TAA and may have negatively affected the prosthesis's survival.

Our initial experiences with MR arthrography / Kezdeti tapasztalataink az MR-artrográfiával.

INTRODUCTION: The gold standard method for shoulder surgery imaging is magnetic resonance imaging (MRI). The sensitivity of the conventional MRI for full thickness tears is way above 85%, for partial rotator cuff lesions this number is less than 40%. Diagnostic accuracy is equally low in detecting different variations of anterior labrum lesion and also in injury of the glenohumeral ligaments. Contrast agent given directly into the joint can improve these diagnostic inaccuracies. METHOD: We made the first shoulder joint related MR arthrography in February 2018 at the Semmelweis University. The studied period lasted for 17 months; during that time 29 examinations were performed. For the injection we used gadolinium-based contrast substance. RESULTS: In the case of 26 patients (89.9%), the contrast substance had a good position and distended well. From all of the shoulder MRI examinations, 9 (31%) surgical interventions were made, and 8 surgical findings had the same diagnosis as the radiologic description. CONCLUSION: The contrast substance given into the intraarticular space makes it easier to identify and detect the structures in the joint. The injection under X-ray screening is safe, it is absorbed from the joint in short time, and so far - based on our experience - there has not been any complication. It can help to identify injuries which are difficult to diagnose with conventional MRI, and helps planning before surgery. Orv Hetil. 2020; 161(36): 1514-1521.

Wear analysis of explanted conventional metal back polyethylene glenoid liners.

INTRODUCTION: Glenoid component wear and loosening is the Achilles heel of total shoulder replacement. Analysis of failed, revised implants might give an insight into the causes of component failure. Volumetric assessment of conventional total shoulder replacement glenoid liner wear rate and scanning electron microscopy was accomplished in this study for the purpose. Coherence scanning interferometry (white light scanner) 3D images were acquired. This method requires no physical contact, ionising radiation or extensive surface preparation. METHODS: Twenty-four Nottingham total shoulder replacement system metal - back glenoid liners were explanted from revision shoulder arthroplasty cases. A Phase Vision Quartz DBE 800 scanner was used to scan the explanted polyethylene liners. The images of worn liners were registered to the reference image. Differences in wear and wear rate were quantified and central and non-central wear groups were distinguished. The Central wear group had a polyethylene wear rate of 115 ±â€¯55mm3/year (mean ±â€¯SD). The non-central group showed a wear rate of 112 ±â€¯42 mm3/year (mean ±â€¯SD), which was not significantly different from the central wear group (p = 0.426) Polyethylene liners showing edge wear from unstable shoulder replacements showed a wear rate of 545 mm3/year. Scanning electron microscopy images showed that the polyethylene was wearing in laminar flakes which indicated fatigue wear. CONCLUSION: The volumetric wear rate was found to be more than twice as fast as in the case of total hip replacement with the acetabular liner made of the same type of polyethylene. Use of coherence scanning interferometry is proposed for wear analysis.

Use of antibiotic-impregnated bone grafts in a rabbit osteomyelitis model.

BACKGROUND: Both osteomyelitis and prosthetic joint infection can be treated surgically with the use of antibiotic loaded bone grafts, as part of local antimicrobial therapy. OBJECTIVE: The purpose of the study was to evaluate and to report on a novel, biodegradable, long-acting (4-6 weeks) antibiotic-impregnated bone graft (AIBG). A novel drug delivery system, containing vancomycin, was utilized in a rabbit osteomyelitis model in order to evaluate the antimicrobial efficacy of the antibiotic bone graft. METHODS: Forty adult New Zealand rabbits were used. The animals were randomized into three Groups: healthy animals without osteomyelitis, where AIBG was used to fill a defect (Group I); osteomyelitis caused with a methicillin-resistant S.aureus strain (MRSA) treated with AIBG (Group II); osteomyelitis caused with MRSA and treated with bone grafts without local antibiotics (Group III). At six weeks post-operation, the animals were sacrificed and histological, laboratory and radiologic evaluations were performed. RESULTS: Of the 24 operated rabbits, osteomyelitis was confirmed in 18 animals. In groups with osteomyelitis, only minor radiological changes were observed on day 21 post-op. Radiographs taken on day 42 post-op showed radiological signs of chronic osteomyelitis in Group III, whereas in Group II, bone healing was observed. Bacterial cultures taken on day 42 post-op revealed the original MRSA strain in Group III, whereas no bacteria were detected in Group II. Histological examinations showed the presence of macrophage cells which slowly break down the DDS matrix. The presence of DDS did not inhibit re-ossification. CONCLUSIONS: The drug delivery system was effective against MRSA-induced osteomyelitis without negative effect on osteointegration. This biodegradable technology has the potential to be a powerful tool in fighting bone infections.