MAUDE Adverse Event Report: NUVASIVE SPECIALIZED ORTHOPEDICS MAGEC SPINAL BRACING AND DISTRACTION SYSTEM; GROWING ROD SYSTEM - MAGNETIC ACTUATION

Model Number UNKNOWN

Device Problems Mechanical Problem (1384); Unstable (1667)

Patient Problem Metal Related Pathology (4530)

Event Type  Injury  

Event Description

Information was receive that dual standard and offset rods were implanted at t5-l4 with claw construct at the proximal foundation (t5-t6) and pedicle screws at the distal foundation (l3-l4).Postoperatively the patient was given a corset with shoulder straps for 3 months before monthly outpatient distractions were performed.Despite the finding of proximal junctional kyphosis (pjk) 5 months after the surgery, early distractions were smooth and successful.At the 11th distraction, one and a half years after rod implantation, rod slippage occurred in both rods and no lengthening was observed.Targeted 2mm distraction was continued at the next two clinics despite continuous rod slippage and failed lengthening.The difficulties were initially contributed to the uncooperative patient who became irritable during distraction sessions.Subsequently, a distraction session under sedation was performed to eliminate the soft tissue resistance contributed by muscle contraction.Despite successful distraction on the left rod, continuous slippage was still observed on the right rod.As further lengthening was unsuccessful, rod exchange was performed with proximal extension to t3-t4 to control the proximal junctional kyphosis.Intraoperatively metallosis was observed around the screw-rod junction.After rod exchange, smooth distractions were again observed for both rods.The patient is now two years after the rod exchange with monthly successful lengthenings.Report 2 of 2.

Manufacturer Narrative

Third party analysis: retrospective examination of the radiographs acquired prior to the sedation procedure revealed rod angulation between the actuator and the extendable portion of the rod.The extracted mcgrs were studied in a mechanical laboratory.Externally there was no rod fracture but there were many wearing marks at the junction between the extended portion of the rod and the actuator.Rod angulation was also observed by placing the rod next to a straight bench edge.After the extended portion and the actuator were dissected, it was revealed that the threads of the internal screw providing the distraction were no longer in-line with such deformation and thus the screw refused to rotate with external magnetic force due to the increased resistance.After the screw was dislodged and re-inserted along the correct threads, the screw was able to rotate manually under external force and the distraction resumed.Literature - title of article: the crooked rod sign - a new radiological sign to detect deformed threads in the distraction mechanism of magnetically controlled growing rods and a mode of distraction failure - authors: jason pui yin cheung, teng zhang, cora bow, kenny kwan, kam yin sze, kenneth man chee cheung.Publication date: 2019.

• Brand Name: MAGEC SPINAL BRACING AND DISTRACTION SYSTEM
• Type of Device: GROWING ROD SYSTEM - MAGNETIC ACTUATION
• Manufacturer (Section D): NUVASIVE SPECIALIZED ORTHOPEDICS; 101 enterprise #100; aliso viejo CA 92656
• Manufacturer (Section G): NUVASIVE SPECIALIZED ORTHOPEDICS; 101 enterprise #100; aliso viejo CA 92656
• Manufacturer Contact: geoff gannon ; 101 enterprise #100; aliso viejo, CA 92656 ; 8583448112
• MDR Report Key: 14116144
• MDR Text Key: 293539121
• Report Number: 3006179046-2022-00171
• Device Sequence Number: 1
• Product Code: PGN
• Combination Product (y/n): N
• Reporter Country Code: HK
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Foreign,Literature,Health Professional
• Reporter Occupation: Physician
• Type of Report: Initial
• Report Date: 04/14/2022

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 04/14/2022
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: UNKNOWN
• Device Lot Number: UNKNOWN
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Was the Report Sent to FDA?: No
• Date Manufacturer Received: 03/23/2022
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Is the Device Single Use?: Yes
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Initial
• Patient Sequence Number: 1
• Patient Outcome(s): Other
• Patient Sex: Female