Devices › Prosthesis, knee, patellofemorotibial, semi-constrained, cemented, polymer/metal/polymer
Device brand name · Prosthesis knee
Unknown Knee: medical device reports filed with FDA
1,847 reports name it, 2011–2026. Manufacturer given most often on reports: Biomet Orthopedics. Product code JWH.
- 1,847
- device reports naming the brand
- 0% of all MAUDE reports · about 121 a year
- 18
- reports, 12 months to August 2026
- 41 in the 12 months before
- 0.3%
- classified as malfunction
- 14.7% across the product code
- 1.5%
- classified as death, as reported
- 28 reports · not verified by FDA
FDA's MAUDE database holds 1,847 reports that name the brand "Unknown Knee" (prosthesis knee), received between April 2011 and April 2026; the manufacturer given most often on reports is Biomet Orthopedics. Spellings of one product vary from report to report.
18 reports arrived in the 12 months to August 2026, down 56% from 41 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 (97%), death (1.5%) and other (1%); across all prosthesis, knee, patellofemorotibial, semi-constrained, cemented, polymer/metal/polymer reports (product code JWH) death is recorded in 0.2% and malfunction in 14.7%. Event type is the reporter's classification of the report, not a verified outcome.
The device problems coded most often are insufficient device problem information (37.5%), loose or intermittent connection (8%) and device dislodged or dislocated (7.7%). The patient problems coded most often are pain, loss of range of motion and bone fracture(s). 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 158,133 reports carrying product code JWH. 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 |
|---|---|---|---|
| Insufficient device problem information | 693 | 37.5% | 18.1% |
| Loose or intermittent connection | 147 | 8% | 2.1% |
| Device dislodged or dislocated | 143 | 7.7% | 1.7% |
| Device slipped | 94 | 5.1% | 1.5% |
| Naturally worn | 74 | 4% | 6.8% |
| Unstable | 70 | 3.8% | 4.3% |
| Migration or expulsion of device | 68 | 3.7% | 1.5% |
| Fracturea broken bone | 53 | 2.9% | 7.3% |
| Device operates differently than expectedthe device behaved unexpectedly | 37 | 2% | 0.8% |
| Loss of or failure to bond | 29 | 1.6% | 6.3% |
| Mechanical problema mechanical problem | 23 | 1.2% | 0.5% |
| Noise, audible | 18 | 1% | 1% |
| Malposition of device | 15 | 0.8% | 0.9% |
| Failure to align | 11 | 0.6% | 0.1% |
| Loss of osseointegration | 10 | 0.5% | 0.9% |
| Inadequacy of device shape and/or size | 7 | 0.4% | 0.5% |
| Breakthe device broke | 6 | 0.3% | 3.9% |
| Material erosion | 6 | 0.3% | 0.2% |
| Detachment of device component | 4 | 0.2% | 0.3% |
| Failure to adhere or bond | 4 | 0.2% | 0.7% |
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 | 434 | 23.5% |
| Loss of range of motion | 84 | 4.5% |
| Bone fracture(s) | 62 | 3.4% |
| Joint dislocationa dislocated joint | 61 | 3.3% |
| Injurya physical injury | 60 | 3.2% |
| Deaththe patient died; cause not stated by this term | 42 | 2.3% |
| Ambulation or postural difficulties | 39 | 2.1% |
| Swellingswelling | 37 | 2% |
| Failure of implant | 29 | 1.6% |
| Swelling/ edema | 27 | 1.5% |
| Arthritis | 24 | 1.3% |
| Fibrosis | 20 | 1.1% |
| Limited mobility of the implanted joint | 20 | 1.1% |
| Scar tissue | 19 | 1% |
| Discomfortdiscomfort | 15 | 0.8% |
Patient problem codes are present mainly in reports filed since 2019 and are often blank.
In context
| Measure | Unknown Knee | Product code JWH | All MAUDE reports |
|---|---|---|---|
| Reports | 1,847 | 158,133 | 26,136,888 |
| Share of that pool | — | 1.2% | 0% |
| Classified as death, per 1,000 reports | 15 | 2 | 9 |
| Classified as injury | 97% | 84.1% | 36.2% |
| Classified as malfunction | 0.3% | 14.7% | 62.3% |
| Filed by the manufacturer | 100% | 98.4% | 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 JWH
| Brand | Reports | Latest 12 months | Classified as death |
|---|---|---|---|
| Unknown Knee Tibial Insert | 2,247 | 130 | 0.2% |
| Unknown Knee Femoral | 1,897 | 65 | 0.2% |
| Unknown Knee Tibial Tray | 1,958 | 57 | 0.2% |
| Persona Tibial Articular Surface Provisional | 1,584 | 0 | 0% |
| Itotal G2 | 1,250 | 0 | 0% |
| Specific Device Not Reported | 1,462 | 20 | 0.2% |
| Apex Knee System | 1,001 | 49 | 0% |
| Djo Surgical | 4,713 | 2,448 | 0% |
| Attune Fb Tib Base Sz 5 Cem | 863 | 18 | 0% |
| Attune Fb Tib Base Sz 4 Cem | 797 | 14 | 0% |
| Pfc Sigma/Ov/Dome Pat 3peg 38 | 806 | 3 | 0.4% |
| Unknown Knee Patella | 791 | 26 | 0.4% |
| Unknown Reconstructive Product | 2,579 | 0 | 0.4% |
| UNK Attune Knee Tibial Insert | 895 | 102 | 0.1% |
| GMK Sphere Total Knee System | 673 | 356 | 0% |
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 Knee reports
How many FDA reports name Unknown Knee?
1,847 medical device reports in the openFDA MAUDE release of 28 Sep 2026, covering reports received through August 2026; 18 in the latest 12 months.
What kinds of events are reported?
injury (97%), death (1.5%) and other (1%). "Event type" is how the report was classified when filed: death, injury, malfunction or other.
What device problems are coded?
insufficient device problem information (37.5%), loose or intermittent connection (8%), device dislodged or dislocated (7.7%), device slipped (5.1%) and naturally worn (4%). These are FDA's device problem codes as entered on the report.
Who files these reports?
manufacturer reports (100%). Manufacturers and user facilities are required to report; voluntary reports come from health professionals and the public.
Do these reports show that Unknown Knee 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.