Cadavers are essential for anatomical education, but limited availability necessitates long-term preservation.While formalin is widely used, it is carcinogenic and alters muscle morphology and joint mobility, reducing anatomical accuracy. The modified Larssen solution (MLS) has shown promise in improving joint flexibility, yet its efficacy remains underexplored. This study aimed to evaluate muscle condition and joint range of motion in rat specimens preserved with 4% formalin followed by MLS immersion, compared to continuous 4% formalin preservation. Eighteen rat cadavers were allocated into three groups: intracardiac perfusion followed by 0.9% NaCl immersion, intracardiac perfusion and threemonth immersion in 4% formalin, and intracardiac perfusion with 4% formalin followed by three-month immersion in MLS. Statistical analysis included the t-test or Mann–Whitney test, depending on data distribution. Pearson correlation was used to assess the relationship between muscle fiber fragmentation and joint range of motion. Data from the NaCl group were excluded due to sample decomposition. The MLS group showed significantly redder muscle color (P<0.05), softer muscle consistency (P<0.05), and a non-significant increase in joint range of motion (P>0.05), without observable muscle fiber fragmentation. Correlation analysis could not be conducted due to the absence of fragmentation. MLS may serve as an effective alternative preservative by maintaining muscle color, texture, and structural integrity. Although the increase in joint mobility was not statistically significant, it was more pronounced than in the 4% formalin group. Future studies should explore longer observation periods and potential correlations with histological findings.

Learning anatomy in medical school is still closely based on the use of cadavers. The burial of preserved cadaver poses a problem, specifically, it contaminates the soil with formalin. Many studies have been conducted to find an alternative fixative to update or modify formalin usage. One of them is ethanol-glycerin (EG), which suggests promising results.Despite that fact, there has yet to be any research comparing the decomposition rate between EG and formalin. This study is conducted to compare the rate of decomposition between the two fixative solutions, EG and 4% formalin on the hind limb of mice. The mice were first preserved using a standard primary fixative solution which is 10% formalin, following that procedure is preservation using advanced fixative solution, EG or 4% formalin. Upon completing the preservation steps, the mice were buried for 6 weeks and observed weekly. The stages of decomposition were assessed semi-quantitatively depending on its appearance. The hind limbs of mice that were fixed with EG solution managed to reach the last stage of decomposition, dry & remains, while the 4% formalin group of mice still remained in the previous stage, advanced decay. It is concluded that the mice hind limbs that have been previously preserved with EG advanced fixative solution has a faster decomposition rate compared to 4% formalin.

Learning anatomy in medical school is still closely based on the use of cadavers. The burial of preserved cadaver poses a problem, specifically, it contaminates the soil with formalin. Many studies have been conducted to find an alternative fixative to update or modify formalin usage. One of them is ethanol-glycerin (EG), which suggests promising results.Despite that fact, there has yet to be any research comparing the decomposition rate between EG and formalin. This study is conducted to compare the rate of decomposition between the two fixative solutions, EG and 4% formalin on the hind limb of mice. The mice were first preserved using a standard primary fixative solution which is 10% formalin, following that procedure is preservation using advanced fixative solution, EG or 4% formalin. Upon completing the preservation steps, the mice were buried for 6 weeks and observed weekly. The stages of decomposition were assessed semi-quantitatively depending on its appearance. The hind limbs of mice that were fixed with EG solution managed to reach the last stage of decomposition, dry & remains, while the 4% formalin group of mice still remained in the previous stage, advanced decay. It is concluded that the mice hind limbs that have been previously preserved with EG advanced fixative solution has a faster decomposition rate compared to 4% formalin.