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.

Background: Acromioclavicular (AC) joint dislocations are frequent, especially kocsisamong young male athletes. While over 150 surgical techniques exist, consensus on optimal treatment—particularly for Rockwood type III injuries—remains elusive. This study evaluates the Lockdown procedure’s efficacy, safety, and patient satisfaction, a synthetic ligament technique for AC joint stabilization. Methods: A multicenter prospective study was conducted on 39 patients across three Hungarian hospitals (2018–2023). Outcomes included shoulder function, pain levels, and complication rates, with subgroup analysis of acute (≤3 weeks) versus chronic (>3 weeks) cases. A systematic review of nine studies (205 cases) was also performed to assess broader outcomes and complications. Results: Significant improvements were observed in functional scores (OSS, Constant, DASH, SST, ASES, Nottingham, Imitani) and pain reduction, especially in acute cases with no prior shoulder surgery. The mean patient age was 38.9 ± 12.68 years, with a 24.5-month average follow-up. OSS improvement between acute and chronic cases was 14.96 (95% CI: 6.45–23.47; p = 0.0017). Complications (30.8%) occurred in eleven patients, mainly minor infections; implant failure necessitated revision in 5.1%. The systematic review reported a 34.6% complication rate (predominantly minor complications, like asymptomatic subluxation −16%) and 5.4% implant removal due to failure. A meta-analysis was not feasible due to data heterogeneity. Conclusions: The Lockdown procedure significantly enhances shoulder function and reduces pain, particularly in acute dislocations. However, the procedure showed a moderate complication rate, underscoring the need for careful patient selection and postoperative management.

The following work introduces a method to carry out patient specific implant design based on computer tomography (CT) imaging technique. Point cloud bone model and the solid model creation process is described in detail. Using the radiodensity level of the CT-scan the continuous distribution of the elastic properties of the bone is also been recorded and used for the material model of the finite element procedure. For this purpose, a continuous mass density – elastic modulus curve is suggested, based on previous results in the literature. Stress shielding poses a serious issue regarding the survival of an implant. Strain energy density (SED) is a good indicator of the effects that drive the remodeling. Based on local SED difference caused by the implant this phenomenon can be quantified and visualized. This makes it possible to classify or redesign the implant in order to minimize the potential bone loss caused by the altered stress state.