Mazor X Surgical Robot Malfunctions: What Spine Patients Need to Know

The Mazor X and Mazor X Stealth Edition are robotic guidance systems for spine surgery, developed by Mazor Robotics and acquired by Medtronic in 2018 for $1.7 billion. The system is used primarily in spinal fusion procedures to guide the placement of pedicle screws: it plans the screw trajectories, positions a guidance arm, tracks the real-time position of surgical instruments relative to the patient's spine, and displays that position on a navigation screen. It is marketed to hospitals and surgical centers as a safer, more accurate alternative to freehand technique.

The robot is not autonomous. The surgeon does the drilling and places the screws. What the system supplies is information — the trajectory and the live position of the instruments. The promise to patients is simple: the robot knows exactly where the instruments are. The FDA's recall record for this system documents the question that promise leaves open: what happens when it doesn't.

The central danger with the Mazor X is not a robot arm moving on its own. It is the system displaying inaccurate information about where instruments actually are inside the patient. Pedicle screws are placed millimeters from the spinal cord, exiting nerve roots, and major blood vessels, and during a navigated procedure the surgeon is steering substantially by the screen. If the display lags behind the instrument's true position, or shows a trajectory that does not match reality, the surgeon can breach a pedicle wall or enter the spinal canal while the screen shows a perfect placement.

This failure mode is insidious in the medical record. The operative note will typically say the screws were placed under robotic guidance without complication — because from the surgeon's side, that is what appeared to happen. The injury declares itself afterward, in the recovery room or the following days, and the evidence that the navigation was wrong may exist only in the device's own logs and the intraoperative imaging.

The FDA's device recall database lists four recalls for the Mazor X system. Two concern exactly the navigation-integrity problem described above, and both are recent:

December 2025 (recall Z-1122-2026, initiated December 10, 2025): software errors that, in the FDA's words, "can result in incorrect surgical instrument positioning during spinal surgery." This recall remains open.

July 2024 (recall Z-3156-2024, initiated July 17, 2024): software anomalies causing two distinct problems — a lagging screen display during a navigated procedure, and the potential for a mismatch between the navigated screw and the screw information presented on the screen.

July 2019 (recall Z-0721-2020, initiated July 2, 2019): "Snapshot Tracker" kits — components used to register the patient's anatomy to the navigation system — were not manufactured to specification, creating the potential for navigational inaccuracies that could result in nerve damage or neurological dysfunction.

December 2019 (recall Z-2330-2020, initiated December 5, 2019): a hardware defect in the Positioner Type II. Air leakage in a pneumatic locking system meant the surgical system could unexpectedly detach from the operating room table during a procedure — with the potential to fall onto the patient, causing blunt injuries including hemorrhage, hematoma, and bone fractures. Medtronic issued an Urgent Field Safety Notice for this defect.

These are Class 2 recalls — the FDA category for defects that can cause temporary or medically reversible harm, or where serious harm is possible but less likely. A recall does not mean every surgery with the device went wrong. It means the manufacturer and the FDA have documented specific, known ways this system can fail. For an injured patient, the question becomes whether one of those documented failure modes appears in their case.

The spine is one of the most unforgiving environments in surgery. A screw that breaches the medial wall of a pedicle sits against the spinal cord or a nerve root. The injuries associated with misplaced screws and instruments include permanent motor deficits, nerve root injuries, durotomies (tears in the dural covering of the spinal cord), radiculopathy (radiating pain, numbness, and weakness), bowel and bladder dysfunction, cauda equina syndrome — a surgical emergency — and, in the worst cases, partial or complete paralysis.

The FDA's MAUDE adverse-event database contains reports of exactly this pattern with the Mazor X: in one report, navigation was inaccurate by approximately 2 millimeters at the L2 vertebra, resulting directly in a nerve injury. In another, the robotic arm was directed to inaccurate trajectories at L5. Two millimeters is the difference between a screw in bone and a screw against a nerve.

Revision surgery is itself part of the injury. Repositioning a misplaced screw means another anesthesia, another exposure through healing tissue, more scarring, and a spine that has now been instrumented twice. Patients who go through it should understand that the need for the revision may not have been bad luck.

It is worth being precise here, because device litigation is often caricatured as anti-technology. The peer-reviewed literature on robot-assisted spine surgery reports high overall screw accuracy — often above 99% — and a multicenter five-year analysis (Lee et al., Journal of Spine Surgery, 2022) found that intraoperative screw exchanges fell from 2.7% to 0.8% and robot abandonment fell from 7.1% to 1.1% as the platforms matured, while the 90-day reoperation rate held around 2.8%. Most robot-assisted spine procedures go as planned.

But aggregate accuracy statistics say nothing about the individual case in which the software displayed wrong information — which is precisely the defect the 2024 and 2025 recalls document. A patient injured by a navigation error is not a statistic that averages out; they are the numerator the recall exists to prevent. Litigation is about what happened in one operating room, on one date, with one device running one software version. That is a records question, not a debate about whether surgical robots are good.

Surgical robot cases sit at the intersection of products liability and medical malpractice, and depending on the facts, three different defendants may bear responsibility.

The manufacturer (Medtronic/Mazor). Under products liability law, a manufacturer can be held responsible if a defective device delivered inaccurate surgical guidance data that caused injury — regardless of whether the surgeon used the system correctly. The recall record matters here: a documented software defect that matches the mechanism of injury is the backbone of this theory.

The hospital or surgical center. Facilities can be liable if they failed to maintain the system, failed to install corrective software updates after a recall, failed to adequately train staff on the system's limitations, or kept using a unit after warnings of malfunction. Whether the recalled software version was still running on the date of surgery is a discoverable fact.

The surgeon. A surgeon may be liable for medical malpractice if they continued to rely on navigation data after clear signs of inaccuracy appeared, or failed to independently verify instrument placement — for example, with intraoperative imaging — where the standard of care required it.

These theories are typically pursued together, and the defendants point at one another: the manufacturer says the surgeon misused the system, the surgeon says the display was wrong, the hospital says it maintained everything properly. The device logs, software version records, and intraoperative imaging usually decide who is right.

One more path matters for our practice: robot-assisted spine surgery is performed at VA medical centers as well. If the injury happened at a VA or other federal facility, the claim proceeds under the Federal Tort Claims Act — with its own two-year administrative deadline and mandatory SF-95 claim — rather than state law. See our FTCA article for how those cases work.

Building one of these cases requires the surgical records, the robotic system's log files, the intraoperative imaging, the navigation screenshots if captured, and the device's maintenance and software-version history. This evidence is perishable. Hospitals overwrite logs, service records scatter, and the device itself may be serviced or replaced by the manufacturer's field engineers. The earlier a preservation letter goes out, the more of the record survives.

You do not need to know whether the robot failed before contacting a lawyer — that is what the investigation is for. The signs worth investigating: new or worsened nerve symptoms after a robot-assisted fusion, a revision surgery to reposition screws, or being told after the fact that a screw was "close" or had "breached" a pedicle wall. Peter Anderson reviews these inquiries personally, and the case review is free. The statutes of limitations are unforgiving — two years in Virginia, three in D.C. and Maryland, with narrow exceptions — so the time to ask is when the question first occurs to you.