Background
Implant rotation is a known complication to breast reconstruction using anatomical implants. However, there is a lack of large studies investigating the risk of implant rotation and potential predisposing risk factors.

Method
We reviewed the medical records of all patients who underwent breast reconstruction with Mentor anatomical implants from 2010 to 2021 at two Danish hospitals. We compared the risk of implant rotation between one- and two-stage breast reconstruction using univariate logistic regression. We analyzed the effect of biological mesh, immediate versus delayed reconstruction, and use of a higher final expander volume than the permanent implant volume on the risk of implant rotation. Finally, we analyzed the success rate of revision surgery for implant rotation.

Results
In total, 1134 patients were enrolled. Patients who underwent two-stage breast reconstruction (n = 720) had a significantly higher risk of implant rotation than those who underwent one-stage breast reconstruction (n = 426; 11% vs. 5%, p < 0.01). There was no significant association between implant rotation and the use of biological mesh, immediate breast reconstruction, or use of a higher final expander volume than the permanent implant volume. The success rate of revision surgery after implant rotation was 73% (62/85 rotations).

Conclusions
Two-stage breast reconstruction significantly increased the risk of implant rotation compared to one-stage breast reconstruction. The overall risk of implant rotation was low and success rate of revision surgery was high. These findings suggest that anatomical implants are safe to use for breast reconstruction. However, surgeons and patients should be aware of the increased risk of implant rotation after two-stage reconstruction.