Posterior cervical screw system: medical device reports filed with FDA

2,215 reports carry this product code, 2015–2026; 12 brands with a page.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "Although MDRs are a valuable source of information, this passive surveillance system has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data. In addition, the incidence or prevalence of an event cannot be determined from this reporting system alone due to potential under-reporting of events and lack of information about frequency of device use." And: "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

2,215
reports with this product code: 0% of all MAUDE reports; 143
reports, 12 months to August 2026: 198 in the 12 months before; 34.3%
classified as malfunction: 62.3% across all reports; 0.7%
classified as death, as reported: 0.9% across all reports

Product code NKG is FDA's classification for "Posterior cervical screw system" (orthopedic panel), a class 2 device. 2,215 medical device reports carry this product code, 0% of the MAUDE database, from June 2015 to August 2026.

143 reports arrived in the 12 months to August 2026, down 28% from 198 in the 12 months before. FDA releases MAUDE data monthly; reports can arrive months after an event, so the newest months grow in later releases. The event types recorded are injury (65%), malfunction (34.3%) and death (0.7%). 12 brand names with a page on this site carry this code; the brands table is ordered by report count for navigation only. FDA states that "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices." It adds that the reporting system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data."

Brands with this product code

Brand	Reports	Latest 12 months	Classified as death	Classified as malfunction
Ti Locking Screw	245	0	0%	4.3%
Unknown_Spine_Product	63	24	0%	34.4%
Unknown K2m Product	47	37	0%	38.3%
Symphony	27	133	1.6%	42.3%
Stardrive Screwdriver Shaft T8 105mm	15	43	0%	96.4%
Vertex Reconstruction System	11	9	0.3%	51.1%
Unknown Cage/Spacer	3	4	0%	6.4%
UNK - Constructs: Plate/Screws	2	9	0%	0.2%
Unknown Screw/Rod Construct Accessories	2	0	0%	1%
Invictus	1	0	0%	74.3%
Star	1	50	0%	9%
Unk - Screws	1	0	0%	7.8%

Ordered by report count for navigation only. FDA states that "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices." It adds that the reporting system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data."

Manufacturers named

Manufacturer (as written on reports)	Reports	Share
Wrights Lane Synthes USA Products	474	21.4%
K2m	364	16.4%
Stryker Spine-US	210	9.5%
Medos International S Rl Ch	191	8.6%
Nuvasive	66	3%
Depuy Synthes Spine	36	1.6%
Depuy Spine	25	1.1%
Alphatec Spine	21	0.9%
Synthes Brandywine	18	0.8%
Globus Medical	11	0.5%
Warsaw Orthopedics	11	0.5%
Stryker Spine-France	1	0%

Reports by month, five years

FDA releases MAUDE data monthly; reports can arrive months after an event, so the newest months grow in later releases.

Event type and report source

Event type

Death0.7%15

Injury65%1,439

Malfunction34.3%759

Other0.1%2

Not given0%0

Who filed

Manufacturer report98.2%2,175

Voluntary report0.7%16

User facility report0%0

Distributor report0.9%21

Not given0.1%3

Grey bar: all 26,136,888 MAUDE reports.

Device problems coded

Device problem (FDA code)	Reports	Share
Fracturea broken bone	318	14.4%
Migrationthe device moved from where it was placed	298	13.5%
Breakthe device broke	296	13.4%
Detachment of device or device componentpart of the device came off	90	4.1%
Insufficient device problem information	66	3%
Device-device incompatibility	50	2.3%
Device dislodged or dislocated	44	2%
Torn material	42	1.9%
Unintended movement	41	1.9%
Material integrity problema problem with the device material	39	1.8%
Material twisted/bent	38	1.7%
Material separation	34	1.5%
Mechanical problema mechanical problem	31	1.4%
Device slipped	26	1.2%
Patient device interaction problem	25	1.1%
Migration or expulsion of device	24	1.1%
Loose or intermittent connection	21	0.9%
Loosening of implant not related to bone-ingrowth	19	0.9%
Compatibility problem	17	0.8%
Material deformation	17	0.8%

Questions about posterior cervical screw system reports

What is product code NKG?

FDA's classification code for "Posterior cervical screw system", class 2, reviewed by the orthopedic panel. Every device report carries the product code of the device involved.

How many reports carry this code?

2,215 reports through August 2026, 143 of them in the latest 12 months.

Which brands appear most often?

Ti Locking Screw (245), Unknown_Spine_Product (63), Unknown K2m Product (47), Symphony (27) and Stardrive Screwdriver Shaft T8 105mm (15). Widely used products collect more reports because more people use them.

Can the brands table be used to rank the devices?

No. FDA states that "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices." It adds that the reporting system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data." Brands differ in how many are in use, how long they have been sold and how reports are collected.

Where this comes from. Counts are built from the openFDA Device Adverse Event (MAUDE) bulk export released 28 Sep 2026, which holds reports FDA received through 31 Aug 2026. Brand, generic and manufacturer names are as written on the reports; product code names come from FDA's device classification. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.