Devices › Screw, fixation, bone
Device brand name · Prosthesis hip
Unknown Screw: medical device reports filed with FDA
1,222 reports name it, 2011–2026. Manufacturer given most often on reports: Zimmer Biomet. Product code HWC.
- 1,222
- device reports naming the brand
- 0% of all MAUDE reports · about 82 a year
- 156
- reports, 12 months to August 2026
- 135 in the 12 months before
- 11.3%
- classified as malfunction
- 30.8% across the product code
- 0%
- classified as death, as reported
- 0 reports · not verified by FDA
1,222 medical device reports received by FDA name the brand "Unknown Screw" (prosthesis hip); the manufacturer given most often on reports is Zimmer Biomet; received from August 2011 to August 2026. Brand names are as the reporter or manufacturer wrote them, so one product can appear under several spellings.
156 reports arrived in the 12 months to August 2026, up 16% from 135 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 (88.7%) and malfunction (11.3%); across all screw, fixation, bone reports (product code HWC) death is recorded in 0.1% and malfunction in 30.8%. Event type is the reporter's classification of the report, not a verified outcome.
The device problems coded most often are fracture (19.9%), loosening of implant not related to bone-ingrowth (10.6%) and migration (9.4%). The patient problems coded most often are pain, failure of implant and nonunion/delayed-union bone fracture. 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."
Reports by month, five years
Reports by the month FDA received them. FDA releases MAUDE data monthly; reports can arrive months after an event, so the newest months grow in later releases.
By year received
Event type and report source
Event type, as classified on the report
Who filed the report
Grey bar: all 58,946 reports carrying product code HWC. Event type is the filer's classification and is not verified by FDA.
Device problems coded
| Device problem (FDA code) | Reports | Share | Share across product code |
|---|---|---|---|
| Fracturea broken bone | 243 | 19.9% | 4.2% |
| Loosening of implant not related to bone-ingrowth | 129 | 10.6% | 0.6% |
| Migrationthe device moved from where it was placed | 115 | 9.4% | 4.4% |
| Insufficient device problem information | 75 | 6.1% | 4.3% |
| Breakthe device broke | 62 | 5.1% | 26.4% |
| Migration or expulsion of device | 51 | 4.2% | 2.1% |
| Device dislodged or dislocated | 29 | 2.4% | 1.8% |
| Malposition of device | 25 | 2% | 0.5% |
| Loss of osseointegration | 19 | 1.6% | 0.5% |
| Osseointegration problem | 17 | 1.4% | 0.1% |
| Difficult to removethe device was hard to remove | 15 | 1.2% | 1.4% |
| Loss of or failure to bond | 15 | 1.2% | 0.1% |
| Detachment of device or device componentpart of the device came off | 13 | 1.1% | 0.6% |
| Loose or intermittent connection | 13 | 1.1% | 0.6% |
| Corrodedthe device corroded | 9 | 0.7% | 0.3% |
| Difficult to insertthe device was hard to insert | 9 | 0.7% | 1.2% |
| Device slipped | 7 | 0.6% | 1.9% |
| Noise, audible | 7 | 0.6% | 0.1% |
| Unstable | 7 | 0.6% | 0.1% |
| Material deformation | 6 | 0.5% | 1% |
FDA's device problem codes as entered on the report; one report can carry several. Generic codes such as "no apparent adverse event" are left out.
Patient problems coded
| Patient problem (FDA code) | Reports | Share |
|---|---|---|
| Painpain, site not specified | 263 | 21.5% |
| Failure of implant | 169 | 13.8% |
| Nonunion/delayed-union bone fracture | 97 | 7.9% |
| Swelling/ edema | 74 | 6.1% |
| Injurya physical injury | 73 | 6% |
| Aseptic loosening | 41 | 3.4% |
| Osteolysis | 39 | 3.2% |
| Loss of range of motion | 38 | 3.1% |
| Joint dislocationa dislocated joint | 37 | 3% |
| Foreign body in patientpart of a device left in the patient | 34 | 2.8% |
| Bone fracture(s) | 33 | 2.7% |
| Implant pain | 33 | 2.7% |
| Inadequate osseointegration | 31 | 2.5% |
| Metal related pathology | 30 | 2.5% |
| Numbnessnumbness | 27 | 2.2% |
Patient problem codes are present mainly in reports filed since 2019 and are often blank.
In context
| Measure | Unknown Screw | Product code HWC | All MAUDE reports |
|---|---|---|---|
| Reports | 1,222 | 58,946 | 26,136,888 |
| Share of that pool | — | 2.1% | 0% |
| Classified as death, per 1,000 reports | 0 | 1 | 9 |
| Classified as injury | 88.7% | 67.2% | 36.2% |
| Classified as malfunction | 11.3% | 30.8% | 62.3% |
| Filed by the manufacturer | 99.7% | 97.3% | 94.9% |
Shares are of reports, not of devices in use. 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."
Other brands with product code HWC
| Brand | Reports | Latest 12 months | Classified as death |
|---|---|---|---|
| UNK - Screws: Trauma | 3,576 | 288 | 0% |
| UNK - Screws: Locking | 2,331 | 98 | 0% |
| Unk - Screws Cortex | 889 | 16 | 0% |
| Screw | 647 | 0 | 0% |
| UNK - Screws: Nail Distal Locking | 444 | 12 | 0.2% |
| Unknown Screws | 652 | 23 | 1.7% |
| UNK - Screws: CMF | 410 | 280 | 0% |
| UNK - Screws: Locking: Trauma | 276 | 34 | 0% |
| Unk - Screws 3 5 Mm Cortex | 220 | 33 | 0% |
| Unk - Screws Nail Locking | 211 | 19 | 0% |
| UNK - Screws: 2.7 mm VA Locking | 204 | 22 | 0% |
| Unk - Screws Cannulated | 190 | 9 | 0.5% |
| Unk - Screws | 256 | 0 | 0% |
| Locking Screw | 241 | 3 | 0% |
| Ni | 32,939 | 1,587 | 1.8% |
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." FDA also states that "common products may have a higher number of adverse events due to the higher total number of people using the product."
Questions about Unknown Screw reports
How many FDA reports name Unknown Screw?
1,222 medical device reports in the openFDA MAUDE release of 28 Sep 2026, covering reports received through August 2026; 156 in the latest 12 months.
What kinds of events are reported?
injury (88.7%) and malfunction (11.3%). "Event type" is how the report was classified when filed: death, injury, malfunction or other.
What device problems are coded?
fracture (19.9%), loosening of implant not related to bone-ingrowth (10.6%), migration (9.4%), insufficient device problem information (6.1%) and break (5.1%). These are FDA's device problem codes as entered on the report.
Who files these reports?
manufacturer reports (99.7%), distributor reports (0.2%) and voluntary reports (0.1%). Manufacturers and user facilities are required to report; voluntary reports come from health professionals and the public.
Do these reports show that Unknown Screw was at fault?
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." FDA adds that "a causal relationship cannot be established between product and reactions listed in a report."
How do I report a problem with a medical device?
Through FDA MedWatch (Form FDA 3500 for health professionals and consumers), or to the manufacturer. See the guide on how to report.
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. A report counts here when any device it lists carries this brand name after punctuation and capitalisation are normalised. 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.