510(k) · Cleared
ClearedPrimus Spinal Fixation System
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Spinal Elements, Inc. · NKB Thoracolumbosacral Pedicle Screw System
Cleared on Feb 21, 2025 as substantially equivalent to K222516 (Spinal Elements, Inc., 2022) after a 63-day review. Its family tree reaches back 19 generations to 2004. 2 later devices descend from it.
- Decided
- Feb 21, 2025
- Review
- 63 days
- Class
- Class II
- Product code
- NKB
- Recalls
- None
- Predicates
- 1
Its longest line of descent runs back 19 generations to K040583 (2004). 337 ancestors in all, the oldest K781443 (1978). 2 later devices descend from it, 1 citing it directly.
- Root · 19 generations backK040583 Modification to: CD Horizon Spinal SystemMedtronic Sofamor Danek · 2004
- 15 generations between
- 3 generations backK171082 Firebird Spinal Fixation System, Phoenix MIS Spinal Fixation System…Orthofix, Inc. · 2017 · Recalled
- 2 generations backK180179 Firebird® Spinal Fixation Systems: Firebird System; Firebird…Orthofix, Inc. · 2018
- 1 generation backK222516 Mercury® II Spinal SystemSpinal Elements, Inc. · 2022
- This deviceK243916 Primus Spinal Fixation SystemSpinal Elements, Inc. · 2025
- Descendant · cites it directly · 1 of its ownK251154 RIVA Posterior Fixation System; RIVA Posterior Fixation System…Ht Medical D.B.A. Xenix Medical · 2025
- Descendant · 2 generations on · 0 of its ownK262193 RIVA® Posterior Fixation System with NanoACTIV Surface Technology…Xenix Medical · 2026
Show all 19 generations
- Root · 19 generations backK040583 Modification to: CD Horizon Spinal SystemMedtronic Sofamor Danek · 2004
- 18 generations backK041118 Modification to CD Horizon Spinal SystemMedtronic Sofamor Danek · 2004
- 17 generations backK042025 Modification to CD Horizon Spinal SystemMedtronic Sofamor Danek, Inc. · 2004 · Recalled
- 16 generations backK043151 Modification to: CD Horizon Spinal SystemMedtronic Sofamor Danek · 2005
- 15 generations backK050809 CD Horizon Spinal SystemMedtronic Sofamor Danek USA, Inc. · 2005
- 14 generations backK052187 Modification to: CD Horizon Spinal SystemMedtronic Sofamor Danek · 2005
- 13 generations backK053101 CD Horizon Spinal SystemMedtronic Sofamor Danek · 2006
- 12 generations backK091442 CD Horizon Spinal SystemMedtronic Sofamor Danek · 2009
- 11 generations backK091974 Modification to CD Horizon Spinal SystemMedtronic Sofamor Danek USA, Inc. · 2009 · Recalled
- 10 generations backK102555 CD Horizon Spinal SystemMedtronic Sofamor Danek USA, Inc. · 2010
- 9 generations backK112473 CD Horizon Spinal SystemMedtronic Sofamor Danek, Inc. · 2011
- 8 generations backK113174 CD Horizon Spinal SystemMedtronic Sofamor Danek USA, Inc. · 2011 · Recalled
- 7 generations backK121630 Range Spinal SystemK2m, Inc. · 2012
- 6 generations backK130932 Firebird Spinal Fixation SystemOrthofix, Inc. · 2013 · Recalled
- 5 generations backK151488 Firebird Spinal Fixation System/Phoenix MIS Spinal Fixation SystemOrthofix, Inc. · 2015 · Recalled
- 4 generations backK153428 Firebird Spinal Fixation System, Phoenix MIS Spinal Fixation SystemOrthofix, Inc. · 2016 · Recalled
- 3 generations backK171082 Firebird Spinal Fixation System, Phoenix MIS Spinal Fixation System…Orthofix, Inc. · 2017 · Recalled
- 2 generations backK180179 Firebird® Spinal Fixation Systems: Firebird System; Firebird…Orthofix, Inc. · 2018
- 1 generation backK222516 Mercury® II Spinal SystemSpinal Elements, Inc. · 2022
- This deviceK243916 Primus Spinal Fixation SystemSpinal Elements, Inc. · 2025
Most influential descendants
Showing 2 of 2 · See allView FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −19 | K040583 | Modification to: CD Horizon Spinal System | Medtronic Sofamor Danek | 2004 | — |
| −18 | K041118 | Modification to CD Horizon Spinal System | Medtronic Sofamor Danek | 2004 | — |
| −17 | K042025 | Modification to CD Horizon Spinal System | Medtronic Sofamor Danek, Inc. | 2004 | 4 |
| −16 | K043151 | Modification to: CD Horizon Spinal System | Medtronic Sofamor Danek | 2005 | — |
| −15 | K050809 | CD Horizon Spinal System | Medtronic Sofamor Danek USA, Inc. | 2005 | — |
| −14 | K052187 | Modification to: CD Horizon Spinal System | Medtronic Sofamor Danek | 2005 | — |
| −13 | K053101 | CD Horizon Spinal System | Medtronic Sofamor Danek | 2006 | — |
| −12 | K091442 | CD Horizon Spinal System | Medtronic Sofamor Danek | 2009 | — |
| −11 | K091974 | Modification to CD Horizon Spinal System | Medtronic Sofamor Danek USA, Inc. | 2009 | 1 |
| −10 | K102555 | CD Horizon Spinal System | Medtronic Sofamor Danek USA, Inc. | 2010 | — |
| −9 | K112473 | CD Horizon Spinal System | Medtronic Sofamor Danek, Inc. | 2011 | — |
| −8 | K113174 | CD Horizon Spinal System | Medtronic Sofamor Danek USA, Inc. | 2011 | 1 |
| −7 | K121630 | Range Spinal System | K2m, Inc. | 2012 | — |
| −6 | K130932 | Firebird Spinal Fixation System | Orthofix, Inc. | 2013 | 1 |
| −5 | K151488 | Firebird Spinal Fixation System/Phoenix MIS Spinal Fixation System | Orthofix, Inc. | 2015 | 1 |
| −4 | K153428 | Firebird Spinal Fixation System, Phoenix MIS Spinal Fixation System | Orthofix, Inc. | 2016 | 1 |
| −3 | K171082 | Firebird Spinal Fixation System, Phoenix MIS Spinal Fixation System, JANUS… | Orthofix, Inc. | 2017 | 1 |
| −2 | K180179 | Firebird® Spinal Fixation Systems: Firebird System; Firebird Deformity System… | Orthofix, Inc. | 2018 | — |
| −1 | K222516 | Mercury® II Spinal System | Spinal Elements, Inc. | 2022 | — |
| 0 (this device) | K243916 | Primus Spinal Fixation System | Spinal Elements, Inc. | 2025 | — |
| +1 | K251154 | RIVA Posterior Fixation System; RIVA Posterior Fixation System Navigation… | Ht Medical D.B.A. Xenix Medical | 2025 | — |
| +2 | K262193 | RIVA® Posterior Fixation System with NanoACTIV Surface Technology; RIVA®… | Xenix Medical | 2026 | — |
Other ancestors by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 1978 | 1 | 0 |
| 1984 | 2 | 0 |
| 1985 | 1 | 0 |
| 1986 | 2 | 0 |
| 1987 | 1 | 0 |
| 1988 | 2 | 0 |
| 1989 | 1 | 0 |
| 1990 | 3 | 0 |
| 1992 | 7 | 0 |
| 1993 | 2 | 0 |
| 1994 | 7 | 0 |
| 1995 | 15 | 0 |
| 1996 | 10 | 0 |
| 1997 | 11 | 0 |
| 1998 | 20 | 0 |
| 1999 | 8 | 0 |
| 2000 | 22 | 0 |
| 2001 | 23 | 0 |
| 2002 | 22 | 0 |
| 2003 | 20 | 0 |
| 2004 | 26 | 0 |
| 2005 | 22 | 0 |
| 2006 | 17 | 0 |
| 2007 | 6 | 0 |
| 2008 | 17 | 0 |
| 2009 | 6 | 0 |
| 2010 | 8 | 0 |
| 2011 | 8 | 0 |
| 2012 | 6 | 0 |
| 2013 | 3 | 0 |
| 2014 | 7 | 0 |
| 2015 | 5 | 0 |
| 2016 | 4 | 0 |
| 2018 | 1 | 0 |
| 2019 | 2 | 0 |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 2025 | 1 | 0 |
| 2026 | 1 | 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 NKB? 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 NKB device
- #1 K223494 CD Horizon Spinal Systemscore 40.4 · 30 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (1)
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 |
|---|---|---|---|
| * | K222516 | Mercury® II Spinal SystemSummary page 7…ditional 510(k) seeks clearance for minor modifications to the locking mechanism, component dimensions, and instrumentation of the system previously cleared under 510(k) K222516. The intended use, indication for use, technological characteristics, performance characteristics, packaging and labeling, and st… | 2022 |
What descends from it? (2)
1 later device cites it directly; ranked here by how many devices descend from each in turn.
| Number | Device | Decided | Descendants |
|---|---|---|---|
| K251154 | RIVA Posterior Fixation System; RIVA Posterior Fixation System Navigation Instruments | 2025 | 1 |
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?
- The line of descent spans 21 years and passes through 6 companies; a new generation was cleared every 10 months on median.
- 47 of the 337 ancestors have a recall of any class.
- Of its descendants, K251154 (Ht Medical D.B.A. Xenix Medical, 2025) has gone furthest, with 1 descendant of its own.
How does its category compare?
All NKB devicesNKB Thoracolumbosacral Pedicle Screw System: FDA decisions, review times, recalls and adverse event reports over 20 years. 2025, this device’s year, is highlighted.
FDA decisions per year · NKB
24in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · NKB
61in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · NKB
1in 2025
Class I (1 since 2007) Class II/III not classified
Adverse event reports per year · NKB
1,171in 2025
MAUDE reports naming product code NKB, 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 | 38 | 87 | 4 | 34 |
| 2008 | 36 | 59 | 5 | 82 |
| 2009 | 44 | 71 | 33 | 171 |
| 2010 | 37 | 111 | 4 | 462 |
| 2011 | 48 | 84 | 3 | 577 |
| 2012 | 60 | 79 | 13 | 1,747 |
| 2013 | 35 | 73 | 0 | 1,962 |
| 2014 | 46 | 90 | 3 (1) | 1,671 |
| 2015 | 55 | 90 | 3 | 1,446 |
| 2016 | 50 | 84 | 1 | 1,585 |
| 2017 | 63 | 69 | 1 | 1,618 |
| 2018 | 56 | 61 | 3 | 1,684 |
| 2019 | 39 | 84 | 1 | 1,915 |
| 2020 | 48 | 68 | 1 | 2,076 |
| 2021 | 32 | 61 | 0 | 1,745 |
| 2022 | 34 | 88 | 5 | 1,339 |
| 2023 | 44 | 72 | 2 | 919 |
| 2024 | 39 | 57 | 3 | 1,614 |
| 2025 | 24 | 61 | 1 | 1,171 |
| 2026 | 30 | 91 | 3 | — |
What is it indicated for?
The Primus Spinal Fixation System is intended to provide immobilization and stabilization of the spine in skeletally mature patients as an adjunct to fusion for procedures of the thoracic, lumbar, and sacral spine (T1-S1). Screws may be placed from the thoracic spine through the sacral spine and into the ilium. This system is intended for anterior/anterolateral non-pedicle fixation, posterior non-pedicle fixation, and posterior pedicle fixation for the…
Read the full statement (364 words)
The Primus Spinal Fixation System is intended to provide immobilization and stabilization of the spine in skeletally mature patients as an adjunct to fusion for procedures of the thoracic, lumbar, and sacral spine (T1-S1). Screws may be placed from the thoracic spine through the sacral spine and into the ilium. This system is intended for anterior/anterolateral non-pedicle fixation, posterior non-pedicle fixation, and posterior pedicle fixation for the following indications: degenerative disc disease (DDD) (defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies), spondylolisthesis, trauma (i.e., fracture or dislocation), spinal stenosis, curvatures (i.e., scoliosis, kyphosis, and/or lordosis), tumor, pseudoarthrosis, and failed previous fusion.
The Spinal Elements Primus Spinal Fixation System may be used in conjunction with the Spinal Elements Overwatch System. In order to achieve additional levels of fixation, the Primus or Overwatch Fixation Systems may be connected to the Lotus Posterior Cervical/Thoracic rod connectors. Transition rods with differing diameters may also be used to connect the Lotus Posterior Cervical/Thoracic Spinal System to the Primus or Overwatch Spinal Systems. Refer to the Lotus Posterior Cervical/Thoracic Spinal System package insert for a list of Lotus indications for use.
When used for posterior non-cervical pedicle screw fixation in pediatric patients, the Primus and Overwatch implants are indicated as an adjunct to fusion to treat adolescent idiopathic scoliosis. Pediatric pedicle screw fixation is limited to a posterior approach.
Spinal Elements’ fenestrated screws are intended to be used with saline or radiopaque dye.
These devices are intended to be used with autograft or allogenic bone graft comprised of cancellous and/or corticocancellous bone graft.
Spinal Elements’ Navigated Instruments are intended to be used during the preparation and placement of Spinal Elements’ Primus screws during spinal surgery to assist the surgeon in precisely locating anatomical structures in either open or minimally invasive procedures. These instruments are designed for use with the Medtronic StealthStation® System, which is indicated for any medical condition in which the use of stereotactic surgery may be appropriate, and where reference to a rigid anatomical structure, such as a vertebra, can be identified relative to a CT or MR based model, fluoroscopy images, or digitized landmarks of the anatomy.
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K243916 · printed Nov 6, 2026
Cite this page
510(k) Report. “K243916: Primus Spinal Fixation System.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K243916
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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