After Johnson & Johnson’s Acclarent unit added a machine-learning algorithm to its TruDi sinus-surgery navigation system in 2021, FDA malfunction reports for the device jumped from 7 to over 100, with at least 10 patients injured through late 2025. Most cases involved the system misinforming surgeons about instrument location inside patients’ heads, including cerebrospinal fluid leaks, a punctured skull base, and two strokes caused by injury to a major artery. The two stroke victims filed lawsuits in Texas alleging the AI contributed to their injuries.