MAUDE Adverse Event Report: MEDTRONIC NAVIGATION, INC. (LOUISVILLE) CLAMP, SPINOUS PROCESS SHORT; ORTHOPEDIC STEREOTAXIC INSTRUMENT

Catalog Number 9734716

Device Problems Mechanical Problem (1384); Device Inoperable (1663); Device Operates Differently Than Expected (2913)

Patient Problems Spinal Column Injury (2081); Injury (2348); Iatrogenic Source (2498)

Event Date 10/21/2016

Event Type  Injury  

Manufacturer Narrative

Device lot number not available.Device manufacturing date is dependent on lot number, therefore, unavailable.Return requested.Replacement spinous process short clamp shipped to site (b)(6) 2016.This suspect clamp was discarded by the site and will not be returned to manufacturer for analysis.On 11/04/2016 a medtronic representative, following-up at the site, reported that the surgeon removed a part of spinous process to take the damaged clamp off from the patient.There was minimum delay due to this cause.The damaged instrument was discarded by the site.

Event Description

A medtronic representative reported that, while in a spinal fusion procedure, the site's spinous process short clamp bolt was completely disengaged, and the clamp could not be loosened.The surgeon removed a part of spinous process to take the damaged clamp off from the patient.No further details regarding this issue, or specifically when it occurred, were provided.The surgeon opted to continue and completed the procedure with the use of the navigation system.Delay in therapy was less than one hour.There was no impact on patient outcome.

Manufacturer Narrative

Additional information: although a specific cause of the reported incident was unconfirmed as the part was not received to the manufacturer, an investigation into returned parts with similar reported malfunctions was completed via capa investigations.The capa investigations found that the spine clamp issue occurs when the user applies torque to the clamp screw that is greater than the weld strength to the captive clamp washer.Excess torque can force the washer to dislodge.Once the washer is dislodged, the clamp screw can be fully disengaged from the instrument.If the washer is disengaged, but the clamp screw is threaded into the instrument, the clamp screw will function for spine clamp application to the spinous process, but the lack of a washer will prevent the clamp from opening.Based on the results of the tests, it can be concluded that the root cause of the failure occurs when the spine clamp¿s drive mechanism is opened by the user to the design travel limits, and then the clamp screw is further torqued by the user in an attempt to open beyond the travel limits and a torque of greater than or equal to 2.72nm is applied.A modified design of the spine clamp was created to help prevent the user from applying excessive torque to the clamp washer when fully open.This prohibits the washer from breaking free of the clamp screw, preventing the clamp from demonstrating the failure mode discovered in the reported incident.

• Brand Name: CLAMP, SPINOUS PROCESS SHORT
• Type of Device: ORTHOPEDIC STEREOTAXIC INSTRUMENT
• Manufacturer (Section D): MEDTRONIC NAVIGATION, INC. (LOUISVILLE); 826 coal creek circle; louisville CO 80027
• Manufacturer (Section G): MEDTRONIC NAVIGATION, INC. (LOUISVILLE); 826 coal creek circle; louisville CO 80027
• Manufacturer Contact: amos jarrette ; 826 coal creek circle; louisville, CO 80027-9710 ; 7208902082
• MDR Report Key: 6115749
• MDR Text Key: 60415132
• Report Number: 1723170-2016-02988
• Device Sequence Number: 1
• Product Code: OLO
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K131425
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative
• Reporter Occupation: Medical Equipment Company Technician/Representative
• Type of Report: Initial,Followup,Followup
• Report Date: 03/23/2017

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 11/19/2016
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Physician
• Device Catalogue Number: 9734716
• Device Lot Number: 160204
• Is the Reporter a Health Professional?: No
• Date Manufacturer Received: 02/03/2017
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 02/04/2016
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Reuse
• Patient Sequence Number: 1
• Patient Outcome(s): Required Intervention
• Patient Age: 74 YR
• Patient Weight: 95