Plate, cranioplasty, preformed, alterable: medical device reports filed with FDA

953 reports carry this product code, 2005–2026; 6 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.

953
reports with this product code: 0% of all MAUDE reports; 247
reports, 12 months to August 2026: 248 in the 12 months before; 78.8%
classified as malfunction: 62.3% across all reports; 0%
classified as death, as reported: 0.9% across all reports

Product code GWO is FDA's classification for "Plate, cranioplasty, preformed, alterable" (neurology panel), a class 2 device. 953 medical device reports carry this product code, 0% of the MAUDE database, from July 2005 to August 2026.

247 reports arrived in the 12 months to August 2026, close to the 248 of 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 malfunction (78.8%), injury (20.7%) and other (0.4%). 6 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 Matrixneuro Screw Self-Drilling 4mm	288	74	0%	60%
Matneu Scr 1 5 Self-Drill L4 Tan 1u I/C	191	62	0%	97.3%
Ti Matrixneuro Screw Self-Drilling 5mm	69	50	0%	79.3%
Unknown_Fro_Product	4	7	0%	36.5%
Matneu Scr 1 5 Self-Drill L4 Tan 4u I/C	2	41	0%	95%
Vertex Reconstruction System	1	9	0.3%	51.1%

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
Stryker Leibinger Freiburg	160	16.8%
Synthes USA	33	3.5%
Biomet Microfixation	9	0.9%
Karl Leibinger Medizintechnik & Kg	5	0.5%
Stryker Medical	1	0.1%

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%0

Injury20.7%197

Malfunction78.8%751

Other0.4%4

Not given0.1%1

Who filed

Manufacturer report99%943

Voluntary report0.9%9

User facility report0%0

Distributor report0%0

Not given0.1%1

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

Device problems coded

Device problem (FDA code)	Reports	Share
Breakthe device broke	480	50.4%
Inadequacy of device shape and/or size	110	11.5%
Failure to cut	39	4.1%
Device-device incompatibility	34	3.6%
Entrapment of device	23	2.4%
Nonstandard device	20	2.1%
Material twisted/bent	17	1.8%
Insufficient device problem information	15	1.6%
Fracturea broken bone	13	1.4%
Crackthe device cracked	12	1.3%
Device contaminated during manufacture or shipping	12	1.3%
Difficult to advance	10	1%
Migrationthe device moved from where it was placed	10	1%
Fitting problem	8	0.8%
Material fragmentation	7	0.7%
Material deformation	6	0.6%
Peeled/delaminated	6	0.6%
Device operates differently than expectedthe device behaved unexpectedly	5	0.5%
Device slipped	5	0.5%
Patient-device incompatibilitythe device did not suit the patient	5	0.5%

Questions about plate, cranioplasty, preformed, alterable reports

What is product code GWO?

FDA's classification code for "Plate, cranioplasty, preformed, alterable", class 2, reviewed by the neurology panel. Every device report carries the product code of the device involved.

How many reports carry this code?

953 reports through August 2026, 247 of them in the latest 12 months.

Which brands appear most often?

Ti Matrixneuro Screw Self-Drilling 4mm (288), Matneu Scr 1 5 Self-Drill L4 Tan 1u I/C (191), Ti Matrixneuro Screw Self-Drilling 5mm (69), Unknown_Fro_Product (4) and Matneu Scr 1 5 Self-Drill L4 Tan 4u I/C (2). 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.