In Vivo Assessment of PCL Cog Thread Reinforcement Using an Intravaginal Force Measurement Device

Background: Pelvic organ prolapse (POP) motivates the development of temporary, biodegradable reinforcements that avoid the long-term drawbacks of permanent meshes. Barbed (cog) poly(ε-caprolactone) (PCL) threads are designed to self-anchor and enhance tissue–implant friction, promoting load redistribution during strain while gradually resorbing. Hypothesis: Compared with non-reinforced controls, PCL cog reinforcement would increase in vivo intravaginal contact forces under standardized loading—consistent with a mechanical reinforcement effect—and would attenuate over time with material resorption. Methods: A prospective longitudinal ovine pilot study (n = 5) was conducted. Intravaginal forces were recorded at 0, 10, 20, and 30 mm speculum openings before implantation (to establish a baseline) and at 90 and 180 days post-surgery using a calibrated force-sensing speculum. All measurements were performed on the same animals at each time point, following an identical protocol. Results: At 90 days post-implantation, intravaginal forces were significantly higher than controls, with the largest increase at 0 mm (+76.0%, p = 0.0003). At 180 days, forces remained above baseline but declined relative to 90 days (+55.3% vs. control, p = 0.0035). Significant reinforcement effects were observed exclusively at 0 mm, while differences at larger openings were smaller and not statistically significant. Conclusions: These findings support the mechanical feasibility of PCL cog threads as a temporary reinforcement strategy compatible with progressive resorption.