The FDA has given a recall on the Zimmer Biomet (NYSE:ZBH) Rosa Brain 3.0 devices for robot-assisted neurosurgery procedures a Class I designation, the most serious type of recall.

Zimmer Biomet warned in September of the problem, in which a sequence workflow can trigger “a discrepancy between initial skin marking on the skull and instrument trajectory,” the Warsaw, Ind.-based company said at the time.

The FDA said today that the problem causes an incorrect positioning of the robotic arm. The company reported that one patient has been injured but that no deaths were reported in connection with the software problem.

Affected devices were manufactured between Feb. 23, 2016, and Dec. 21, 2018. They were distributed until March 2019. The recall covers 86 units in the U.S.

Rosa Brain 3.0 is the neurosurgery version of the Rosa technology that Zimmer Biomet is using to compete with Stryker in the robot-assisted ortho space. Zimmer Biomet acquired the initial Rosa technology through its roughly $132 million purchase of French robot-assisted surgery firm Medtech in 2016.