510(k) · Cleared
ClearedMonkey Rings External Ring Fixation System
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Paragon 28, Inc. · KTT Appliance, Fixation, Nail/Blade/Plate Combination, Multiple Component
Cleared on Dec 19, 2025 as substantially equivalent to K212895 (Paragon 28, Inc., 2021) after a 31-day review. Its family tree reaches back 11 generations to 2000.
- Decided
- Dec 19, 2025
- Review
- 31 days
- Class
- Class II
- Product code
- KTT
- Recalls
- None
- Predicates
- 1
Its longest line of descent runs back 11 generations to K994143 (2000). 15 ancestors in all, the oldest K970748 (1997). No later device cites it as a predicate yet.
- Root · 11 generations backK994143 Smith & Nephew External Fixation System [Unilateral (Linear) &…Smith & Nephew, Inc. · 2000 · Recalled
- 7 generations between
- 3 generations backK182968 Hoffmann LRF SystemStryker GmbH · 2019
- 2 generations backK203568 Hoffmann LRF SystemStryker GmbH · 2021
- 1 generation backK212895 Paragon 28 External Ring Fixation SystemParagon 28, Inc. · 2021
- This deviceK253613 Monkey Rings External Ring Fixation SystemParagon 28, Inc. · 2025
Show all 11 generations
- Root · 11 generations backK994143 Smith & Nephew External Fixation System [Unilateral (Linear) &…Smith & Nephew, Inc. · 2000 · Recalled
- 10 generations backK031181 External Fixation SystemsSmith & Nephew, Inc. · 2003
- 9 generations backK113327 Hoffmann LRF (Limb Reconstruction Frame) SystemStryker Corp. · 2012 · Recalled
- 8 generations backK130334 Hoffmann LRF (Limb Reconstruction Frame System)Stryker Trauma AG · 2013
- 7 generations backK140961 Hoffmann LRF (Limb Reconstruction Frame) SystemStryker Trauma AG · 2014
- 6 generations backK153377 Hoffmann LRF (Limb Reconstruction Frame) SystemStryker GmbH · 2016 · Recalled
- 5 generations backK161753 Hoffman LRF SystemStryker GmbH · 2016
- 4 generations backK163656 Hoffmann LRF SystemStryker GmbH · 2017 · Recalled
- 3 generations backK182968 Hoffmann LRF SystemStryker GmbH · 2019
- 2 generations backK203568 Hoffmann LRF SystemStryker GmbH · 2021
- 1 generation backK212895 Paragon 28 External Ring Fixation SystemParagon 28, Inc. · 2021
- This deviceK253613 Monkey Rings External Ring Fixation SystemParagon 28, Inc. · 2025
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −11 | K994143 | Smith & Nephew External Fixation System [Unilateral (Linear) & Multilateral… | Smith & Nephew, Inc. | 2000 | 19 |
| −10 | K031181 | External Fixation Systems | Smith & Nephew, Inc. | 2003 | — |
| −9 | K113327 | Hoffmann LRF (Limb Reconstruction Frame) System | Stryker Corp. | 2012 | 3 |
| −8 | K130334 | Hoffmann LRF (Limb Reconstruction Frame System) | Stryker Trauma AG | 2013 | — |
| −7 | K140961 | Hoffmann LRF (Limb Reconstruction Frame) System | Stryker Trauma AG | 2014 | — |
| −6 | K153377 | Hoffmann LRF (Limb Reconstruction Frame) System | Stryker GmbH | 2016 | 2 |
| −5 | K161753 | Hoffman LRF System | Stryker GmbH | 2016 | — |
| −4 | K163656 | Hoffmann LRF System | Stryker GmbH | 2017 | 5 |
| −3 | K182968 | Hoffmann LRF System | Stryker GmbH | 2019 | — |
| −2 | K203568 | Hoffmann LRF System | Stryker GmbH | 2021 | — |
| −1 | K212895 | Paragon 28 External Ring Fixation System | Paragon 28, Inc. | 2021 | — |
| 0 (this device) | K253613 | Monkey Rings External Ring Fixation System | Paragon 28, Inc. | 2025 | — |
Other ancestors by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 1997 | 1 | 0 |
| 2000 | 1 | 0 |
| 2004 | 1 | 0 |
| 2013 | 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 KTT? 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 KTT device
- #1 K242861 TrueLok Elevatescore 21.3 · 14 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 |
|---|---|---|---|
| * | K212895 | Paragon 28 External Ring Fixation SystemSummary page 7…previously cleared and remain unchanged in design and function. Primary Predicate: Paragon 28 External Ring Fixation System (K212895) Reference Device: Taylor Spatial Frame (K201253)… | 2021 |
| † | K201253 | Modular Rail System, TAYLOR SPATIAL FRAME External Fixator, JET-X Fixator, ILIZAROV… | 2020 |
What descends from it?
No later submission names this one as a predicate yet.
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 25 years and passes through 5 companies; a new generation was cleared every 1.5 years on median.
- 5 of the 15 ancestors have a recall of any class.
- 1 other device also cites its predicate K212895.
How does its category compare?
All KTT devicesKTT Appliance, Fixation, Nail/Blade/Plate Combination, Multiple Component: FDA decisions, review times, recalls and adverse event reports over 20 years. 2025, this device’s year, is highlighted.
FDA decisions per year · KTT
10in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · KTT
88in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · KTT
2in 2021
Class I (0 since 2007) Class II/III not classified
Adverse event reports per year · KTT
673in 2025
MAUDE reports naming product code KTT, 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 | 9 | 55 | 2 | 45 |
| 2008 | 11 | 73 | 1 | 66 |
| 2009 | 11 | 94 | 2 | 45 |
| 2010 | 12 | 148 | 1 | 121 |
| 2011 | 10 | 157 | 0 | 196 |
| 2012 | 9 | 140 | 4 | 527 |
| 2013 | 7 | 87 | 7 | 898 |
| 2014 | 14 | 129 | 0 | 445 |
| 2015 | 12 | 60 | 0 | 401 |
| 2016 | 10 | 142 | 0 | 400 |
| 2017 | 11 | 184 | 1 | 485 |
| 2018 | 6 | 149 | 14 | 597 |
| 2019 | 8 | 110 | 3 | 800 |
| 2020 | 9 | 200 | 0 | 942 |
| 2021 | 10 | 83 | 2 | 961 |
| 2022 | 3 | 25 | 0 | 627 |
| 2023 | 7 | 29 | 0 | 554 |
| 2024 | 5 | 90 | 0 | 523 |
| 2025 | 10 | 88 | 0 | 673 |
| 2026 | 5 | 68 | 11 | — |
What is it indicated for?
The Monkey Rings TM External Fixation System is intended to be used in adults and pediatric patients that are children aged 2 years to less than 12 years and adolescents aged 12 through 21 years (up to but not including the 22nd birthday). The Monkey Rings External Ring Fixation System is intended to treat the following patient indications in pediatric patients and adults for the treatment and fixation of: • Open and closed fractures • Post-traumatic…
Read the full statement (222 words)
The Monkey Rings TM External Fixation System is intended to be used in adults and pediatric patients that are children aged 2 years to less than 12 years and adolescents aged 12 through 21 years (up to but not including the 22nd birthday).
The Monkey Rings External Ring Fixation System is intended to treat the following patient indications in pediatric patients and adults for the treatment and fixation of:
• Open and closed fractures
• Post-traumatic joint contracture which has resulted in loss of range of motion
• Fractures and disease which generally may result in joint contractures or loss of range of motion and fractures requiring distraction
• Pseudoarthrosis, infected union, non-union, or malunion of long bones
• Limb lengthening by epiphyseal, diaphyseal, or metaphyseal distraction
• Correction of bony or soft tissue deformity (e.g., orthoplastic surgery)
• Correction of segmental bony or soft tissue defects
• Joint arthrodesis
• Management of comminuted intra-articular fractures
• Bone transport
The Monkey Rings External Ring Fixation System is indicated in adults for:
• Osteotomy
• Revision procedure where other treatments or devices have been unsuccessful
• Bone reconstruction procedures
• Fusions and replantations of the foot
• Charcot foot reconstruction
• Offloading and/or immobilization of ulcers and/or wounds of the foot and ankle
• Lisfranc dislocations
• Ankle distraction (arthrodiastasis)
• Septic fusion
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K253613 · printed Nov 5, 2026
Cite this page
510(k) Report. “K253613: Monkey Rings External Ring Fixation System.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 5, 2026. https://510kreport.com/device/K253613
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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