A basic study on the mechanical properties of synthetic absorbable sutures under various pH conditions in vitro

In veterinary surgery, the choice of suture is determined by the surgeon based on a combination of factors, such as differences in disassembly time, price, and suture site. However, no unified comparison has been made across companies, and the differences are often unclear. In this study, we compared the mechanical properties (maximum tensile load, maximum extension, and maximum twist) of seven synthetic absorbable sutures at baseline (day 0) and over time under different pH conditions (PBS: pH 7.2, acidic: pH 5.6, alkaline: pH 8.8). At baseline, the comparison showed no significant difference in tensile load, but monofilament sutures exhibited a significantly higher extension than multifilament sutures. In terms of twist, the results varied, with significantly higher values for PDS II and MonoSynthe, both of which are polydioxanone based, suggesting that material differences may have influenced the results. On the other hand, multifilament sutures showed lower values over time in all conditions compared to monofilament sutures. Therefore, it was concluded that multifilaments were more strongly affected by solution immersion than monofilaments and lost their mechanical properties earlier. The results also revealed distinct patterns in twist behavior over time, especially MonoSynthe exhibited much lower twist values under alkaline pH compared to other monofilament sutures. These results suggest that twist could be a valuable addition to conventional evaluation methods for suture characteristics. Further multifaceted evaluations will contribute to the development of more comprehensive selection criteria for sutures used in veterinary clinical practice.