510(k) · Cleared
ClearedFirst Step Unicompartmental Knee System
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Howmedica Osteonics Corp. · HSX Prosthesis, Knee, Femorotibial, Non-Constrained, Cemented, Metal/Polymer
Cleared on Nov 16, 1999 after a 132-day review. The FDA summary names its predicate without a number. 122 later devices descend from it.
- Decided
- Nov 16, 1999
- Review
- 132 days
- Class
- Class II
- Product code
- HSX
- Recalls
- None
- Predicates
- 0
122 later devices descend from it, 4 citing it directly.
- This deviceK992287 First Step Unicompartmental Knee SystemHowmedica Osteonics Corp. · 1999
- Descendant · cites it directly · 121 of its ownK033769 Eius Unicompartmental Knee SystemHowmedica Osteonics Corp. · 2004
- Descendant · 2 generations on · 62 of its ownK043570 Unicondylar Knee Repair System / Conformis UcdConformis, Inc. · 2005 · Recalled
- Descendant · cites it directly · 56 of its ownK080368 Mako Surgical Corp. Unicondylar Knee Implant System IIMako Surgical Corp. · 2008
- Descendant · 2 generations on · 51 of its ownK082172 Mako Modular Knee Compartmental Implant SystemMako Surgical Corporation · 2008 · Recalled
- Descendant · 3 generations on · 50 of its ownK090763 Restoris Multicompartmental Knee (MCK) SystemMako Surgical Corporation · 2009 · Recalled
Showing 5 of 122 descendants. See all descendants
Descendants cleared per year
Most influential descendants
Showing 5 of 122 · See all- K033769Eius Unicompartmental Knee SystemHowmedica Osteonics Corp. · 2004 · cites it directly121descendants
- K043570Unicondylar Knee Repair System / Conformis UcdConformis, Inc. · 2005 · 2 generations on62descendants
- K080368Mako Surgical Corp. Unicondylar Knee Implant System IIMako Surgical Corp. · 2008 · cites it directly56descendants
- K082172Mako Modular Knee Compartmental Implant SystemMako Surgical Corporation · 2008 · 2 generations on51descendants
- K090763Restoris Multicompartmental Knee (MCK) SystemMako Surgical Corporation · 2009 · 3 generations on50descendants
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| 0 (this device) | K992287 | First Step Unicompartmental Knee System | Howmedica Osteonics Corp. | 1999 | — |
| +1 | K033769 | Eius Unicompartmental Knee System | Howmedica Osteonics Corp. | 2004 | — |
| +2 | K043570 | Unicondylar Knee Repair System / Conformis Ucd | Conformis, Inc. | 2005 | 3 |
| +1 | K080368 | Mako Surgical Corp. Unicondylar Knee Implant System II | Mako Surgical Corp. | 2008 | — |
| +2 | K082172 | Mako Modular Knee Compartmental Implant System | Mako Surgical Corporation | 2008 | 2 |
| +3 | K090763 | Restoris Multicompartmental Knee (MCK) System | Mako Surgical Corporation | 2009 | 5 |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 2004 | 1 | 0 |
| 2005 | 2 | 0 |
| 2006 | 4 | 0 |
| 2007 | 5 | 0 |
| 2008 | 5 | 0 |
| 2009 | 3 | 0 |
| 2010 | 1 | 0 |
| 2011 | 3 | 0 |
| 2012 | 7 | 0 |
| 2013 | 7 | 0 |
| 2014 | 7 | 0 |
| 2015 | 3 | 0 |
| 2016 | 7 | 0 |
| 2017 | 4 | 0 |
| 2018 | 3 | 0 |
| 2019 | 8 | 0 |
| 2020 | 9 | 0 |
| 2021 | 10 | 0 |
| 2022 | 5 | 0 |
| 2023 | 10 | 0 |
| 2024 | 6 | 0 |
| 2025 | 5 | 0 |
| 2026 | 7 | 0 |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in HSX? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
Top candidate predicates for a new HSX device
- #1 K261609 Freedom Partial Knee Systemscore 15.1 · 12 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (2)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | — | Duracon Unicompartmental Knee Named without a submission number | |
| * | — | SCR Uni Knee Systems Named without a submission number |
What descends from it? (122)
See all 1224 later devices cite it directly; ranked here by how many devices descend from each in turn.
Has anything in its family been recalled? (0 Class I)
No FDA recall names this device.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- Of its descendants, K033769 (Howmedica Osteonics Corp., 2004) has gone furthest, with 121 descendants of its own.
How does its category compare?
All HSX devicesHSX Prosthesis, Knee, Femorotibial, Non-Constrained, Cemented, Metal/Polymer: FDA decisions, review times, recalls and adverse event reports over 20 years.
FDA decisions per year · HSX
4in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · HSX
59in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · HSX
2in 2020
Class I (0 since 2007) Class II/III not classified
Adverse event reports per year · HSX
175in 2025
MAUDE reports naming product code HSX, not matched to any one device; reports are not rates.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 6 | 33 | 0 | 6 |
| 2008 | 4 | 102 | 0 | 4 |
| 2009 | 2 | — | 49 | 21 |
| 2010 | 3 | 74 | 0 | 58 |
| 2011 | 1 | — | 0 | 114 |
| 2012 | 5 | 88 | 0 | 83 |
| 2013 | 2 | — | 1 | 79 |
| 2014 | 0 | — | 0 | 66 |
| 2015 | 1 | — | 0 | 57 |
| 2016 | 3 | 147 | 1 | 107 |
| 2017 | 5 | 160 | 4 | 113 |
| 2018 | 2 | — | 0 | 159 |
| 2019 | 7 | 90 | 0 | 177 |
| 2020 | 4 | 40 | 2 | 273 |
| 2021 | 7 | 81 | 0 | 240 |
| 2022 | 2 | — | 0 | 257 |
| 2023 | 1 | — | 0 | 231 |
| 2024 | 4 | 133 | 0 | 172 |
| 2025 | 4 | 59 | 0 | 175 |
| 2026 | 2 | — | 0 | — |
What is it indicated for?
The First Step Unicompartmental Knee System consists of a distal femoral resurfacing component and a proximal tibial resurfacing component. The subject components of the First Step Unicompartmental Knee System are single use devices which are sold sterile. The First Step Unicompartmental Knee System is intended for cemented use only. The specific indications and contraindications of the First Step Unicompartmental Knee System are stated in the following…
Read the full statement (104 words)
The First Step Unicompartmental Knee System consists of a distal femoral resurfacing component and a proximal tibial resurfacing component. The subject components of the First Step Unicompartmental Knee System are single use devices which are sold sterile. The First Step Unicompartmental Knee System is intended for cemented use only.
The specific indications and contraindications of the First Step Unicompartmental Knee System are stated in the following sections.
Indications
Moderately disabling joint disease of the knee resulting from painful osteo- or post traumatic arthritis.
Revision of previous unsuccessful unicompartmental knee replacement or other procedure.
As an alternative to tibial osteotomy in patients with unicompartmental osteoarthritis.
Indications for use read by OCR from a scanned FDA summary, so letters may be misread. Check the PDF before quoting it.
https://510kreport.com/device/K992287 · printed Nov 6, 2026
Cite this page
510(k) Report. “K992287: First Step Unicompartmental Knee System.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K992287
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026