510(k) · Cleared

Recalled · Class II · 2026

Triathlon® Hinge Knee System

K223528510(k) TraditionalCleared Jan 20, 202358-day reviewClass II21 CFR 888.3510Recalls 1

Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly, last Nov 3, 2026

Howmedica Osteonics Corp., Dba Stryker Orthopaedics · KRO Prosthesis, Knee, Femorotibial, Constrained, Cemented, Metal/Polymer

Cleared on Jan 20, 2023 as substantially equivalent to K994207 (Howmedica Osteonics Corp., 2000) and 9 other predicates after a 58-day review. Its family tree reaches back 10 generations to 1994. 4 later devices descend from it. It has been recalled once.

Decided: Jan 20, 2023
Review: 58 days
Class: Class II
Product code: KRO
Recalls: 1
Predicates: 10

Its longest line of descent runs back 10 generations to K943462 (1994). 92 ancestors in all, the oldest K811630 (1981). 4 later devices descend from it, 3 citing it directly.

By dateBy generation

Root · 10 generations backK943462 Darwin Knee SystemJohnson & Johnson Professionals, Inc. · 1994 · Recalled
6 generations between
3 generations backK133039 Restoris Multicompartmental Knee SystemMako Surgical Corporation · 2013
2 generations backK150307 RESTORIS Multicompartmental Knee SystemMako Surgical Corp. · 2015
1 generation backK172326 Triathlon Total Knee System, Triathlon PKR System, Restoris MCK Knee…Stryker Orthopaedics · 2017 · Recalled
This deviceK223528 Triathlon® Hinge Knee SystemHowmedica Osteonics Corp., Dba Stryker Orthopaedics · 2023
Descendant · cites it directly · 3 of its ownK230416 Triathlon® Hinge Knee System; Triathlon® Revision Insert X3®Stryker · 2023
Descendant · 2 generations on · 2 of its ownK251665 Triathlon® Hinge Knee SystemHowmedica Osteonics Corp., Dba Stryker Orthopaedics · 2025
Descendant · cites it directly · 0 of its ownK261898 Triathlon® Knee System; Triathlon® Hinge Knee System; Scorpio® Total…Howmedica Osteonics Corp. dba Stryker Orthopaedics · 2026
Descendant · cites it directly · 0 of its ownK252898 Triathlon® Tritanium® Asymmetric Patella; Triathlon® Tritanium®…Howmedica Osteonics Corp., Dba Stryker Orthopaedics · 2025 · Recalled

Show all 10 generations

Root · 10 generations backK943462 Darwin Knee SystemJohnson & Johnson Professionals, Inc. · 1994 · Recalled
9 generations backK033272 Depuy Sigma Tibial InsertsDePuy Orthopaedics, Inc. · 2004 · Recalled
8 generations backK040166 Depuy Sigma XLK Tibial InsertsDePuy Orthopaedics, Inc. · 2004
7 generations backK061648 Depuy Graduated Compartmental Knee (GCK)DePuy Orthopaedics, Inc. · 2006 · Recalled
6 generations backK070849 Depuy GCK Femoral and Tibial ComponentsDePuy Orthopaedics, Inc. · 2007
5 generations backK082172 Mako Modular Knee Compartmental Implant SystemMako Surgical Corporation · 2008 · Recalled
4 generations backK090763 Restoris Multicompartmental Knee (MCK) SystemMako Surgical Corporation · 2009 · Recalled
3 generations backK133039 Restoris Multicompartmental Knee SystemMako Surgical Corporation · 2013
2 generations backK150307 RESTORIS Multicompartmental Knee SystemMako Surgical Corp. · 2015
1 generation backK172326 Triathlon Total Knee System, Triathlon PKR System, Restoris MCK Knee…Stryker Orthopaedics · 2017 · Recalled
This deviceK223528 Triathlon® Hinge Knee SystemHowmedica Osteonics Corp., Dba Stryker Orthopaedics · 2023

Most influential descendants

Showing 4 of 4 · See all

K230416Triathlon® Hinge Knee System; Triathlon® Revision Insert X3®Stryker · 2023 · cites it directly3descendants
K251665Triathlon® Hinge Knee SystemHowmedica Osteonics Corp., Dba Stryker Orthopaedics · 2025 · 2 generations on2descendants
K261898Triathlon® Knee System; Triathlon® Hinge Knee System; Scorpio® Total Knee SystemHowmedica Osteonics Corp. dba Stryker Orthopaedics · 2026 · cites it directly0descendants
K252898Triathlon® Tritanium® Asymmetric Patella; Triathlon® Tritanium® Symmetric Patella…Howmedica Osteonics Corp., Dba Stryker Orthopaedics · 2025 · cites it directly0descendants

View FIG. 1 as a table

Line of descent and top descendants

Generation	Number	Device	Applicant	Decided	Recalls
−10	K943462	Darwin Knee System	Johnson & Johnson Professionals, Inc.	1994	8
−9	K033272	Depuy Sigma Tibial Inserts	DePuy Orthopaedics, Inc.	2004	51
−8	K040166	Depuy Sigma XLK Tibial Inserts	DePuy Orthopaedics, Inc.	2004	—
−7	K061648	Depuy Graduated Compartmental Knee (GCK)	DePuy Orthopaedics, Inc.	2006	1
−6	K070849	Depuy GCK Femoral and Tibial Components	DePuy Orthopaedics, Inc.	2007	—
−5	K082172	Mako Modular Knee Compartmental Implant System	Mako Surgical Corporation	2008	2
−4	K090763	Restoris Multicompartmental Knee (MCK) System	Mako Surgical Corporation	2009	5
−3	K133039	Restoris Multicompartmental Knee System	Mako Surgical Corporation	2013	—
−2	K150307	RESTORIS Multicompartmental Knee System	Mako Surgical Corp.	2015	—
−1	K172326	Triathlon Total Knee System, Triathlon PKR System, Restoris MCK Knee System	Stryker Orthopaedics	2017	1
0 (this device)	K223528	Triathlon® Hinge Knee System	Howmedica Osteonics Corp., Dba Stryker Orthopaedics	2023	—
+1	K230416	Triathlon® Hinge Knee System; Triathlon® Revision Insert X3®	Stryker	2023	—
+2	K251665	Triathlon® Hinge Knee System	Howmedica Osteonics Corp., Dba Stryker Orthopaedics	2025	—
+1	K261898	Triathlon® Knee System; Triathlon® Hinge Knee System; Scorpio® Total Knee System	Howmedica Osteonics Corp. dba Stryker Orthopaedics	2026	—
+1	K252898	Triathlon® Tritanium® Asymmetric Patella; Triathlon® Tritanium® Symmetric…	Howmedica Osteonics Corp., Dba Stryker Orthopaedics	2025	1

Other ancestors by year cleared

Year cleared	Devices	With a Class I recall
1981	1	0
1988	1	0
1990	1	0
1991	3	0
1993	1	0
1995	3	0
1996	3	0
1997	3	0
1998	3	0
1999	2	0
2000	5	0
2001	4	0
2002	5	0
2003	8	0
2004	9	0
2005	8	0
2006	6	0
2007	6	0
2008	3	0
2010	1	0
2013	3	0
2014	1	0
2015	1	0
2017	1	0

Descendants by year cleared

Year cleared	Devices	With a Class I recall
2023	1	0
2025	2	0
2026	1	0

FIG. 1 — Lineage of K223528, 1994–2026Source: FDA 510(k) summaries, read by 510(k) Report · How lineage is built

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 KRO? 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 KRO device

#1 K251665 Triathlon® Hinge Knee Systemscore 19.0 · 12 generations · no Class I recall
#2 Held for the reportin the report
#3 Held for the reportin the report

Get a 510(k) Report

What was it cleared against? (10)

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	Applicant	Decided	Recalls
*	K994207	Howmedica Osteonics Modular Rotating Hinge Knee Summary page 4 …to Which Substantial Equivalence is Claimed: o The components of the Modular Rotating Hinge Knee System: ƒ Modular Rotating Hinge (MRH) Knee Femoral Components – K994207, K002552 ƒ MRH Hinge Tibial Inserts - K994207, K002552 ƒ MRH Sleeve - K994207, K002552 ƒ MRH Tibial Baseplat…	Howmedica Osteonics Corp.	2000	—
*	K002552	Howmedica Osteonics Modular Rotating Hinge Knee Summary page 4 …Substantial Equivalence is Claimed: o The components of the Modular Rotating Hinge Knee System: ƒ Modular Rotating Hinge (MRH) Knee Femoral Components – K994207, K002552 ƒ MRH Hinge Tibial Inserts - K994207, K002552 ƒ MRH Sleeve - K994207, K002552 ƒ MRH Tibial Baseplate - K9942…	Howmedica Osteonics Corp.	2000	—
*	K001548	Modular Rotating Hinge Knee Crossover Tibial Bearing Components Summary page 4 …ibial Inserts - K994207, K002552 ƒ MRH Sleeve - K994207, K002552 ƒ MRH Tibial Baseplate - K994207, K002552 ƒ MRH Tibial Bearing Component - K994207, K001548, K001957, K002552 ƒ MRH Bumper components - K994207, K002552 ƒ MRH Knee Femoral Distal Block – K994207 === Page 5…	Howmedica Osteonics Corp.	2000	—
*	K001957	Modular Rotating Hinge Knee Tibial Rotating Component Summary page 4 …erts - K994207, K002552 ƒ MRH Sleeve - K994207, K002552 ƒ MRH Tibial Baseplate - K994207, K002552 ƒ MRH Tibial Bearing Component - K994207, K001548, K001957, K002552 ƒ MRH Bumper components - K994207, K002552 ƒ MRH Knee Femoral Distal Block – K994207…	Howmedica Osteonics Corp.	2000	—
*	K070095	Triathlon TS Knee System Summary page 5 …ate Devices Used to Support Substantial Equivalence: o The components of the Triathlon® Total Knee System: ƒ Triathlon® Total Stabilized (TS) Femoral Components – K070095, K141056, K172326 ƒ Triathlon® TS Plus Inserts – K070095, K072221, K141056, K172326, K172634 ƒ Triathlon®…	Howmedica Osteonics Corp.	2007	13
*	K141056	Triathlon Knee System Posterior Stabilized Components Summary page 5 …es Used to Support Substantial Equivalence: o The components of the Triathlon® Total Knee System: ƒ Triathlon® Total Stabilized (TS) Femoral Components – K070095, K141056, K172326 ƒ Triathlon® TS Plus Inserts – K070095, K072221, K141056, K172326, K172634 ƒ Triathlon® Universal…	Stryker Orthopaedics	2014	11
*	K172326	Triathlon Total Knee System, Triathlon PKR System, Restoris MCK Knee System Summary page 5 …Substantial Equivalence: o The components of the Triathlon® Total Knee System: ƒ Triathlon® Total Stabilized (TS) Femoral Components – K070095, K141056, K172326 ƒ Triathlon® TS Plus Inserts – K070095, K072221, K141056, K172326, K172634 ƒ Triathlon® Universal Baseplate – K0535…	Stryker Orthopaedics	2017	1
*	K072221	Modification to Triathlon TS Knee System Summary page 5 …hlon® Total Knee System: ƒ Triathlon® Total Stabilized (TS) Femoral Components – K070095, K141056, K172326 ƒ Triathlon® TS Plus Inserts – K070095, K072221, K141056, K172326, K172634 ƒ Triathlon® Universal Baseplate – K053514, K141056, K172326 ƒ Triathlon® Femoral Distal…	Howmedica Osteonics Corp.	2007	—
*	K172634	Triathlon® X3® UHMWPE Tibial Inserts and Patellar Components Summary page 5 …ƒ Triathlon® Total Stabilized (TS) Femoral Components – K070095, K141056, K172326 ƒ Triathlon® TS Plus Inserts – K070095, K072221, K141056, K172326, K172634 ƒ Triathlon® Universal Baseplate – K053514, K141056, K172326 ƒ Triathlon® Femoral Distal Augments – K070095, K14105…	Howmedica Osteonics Corp. A.K.A. Stryker Orthopaedics	2017	7
*	K053514	Triathlon Total Knee System Summary page 5 …mponents – K070095, K141056, K172326 ƒ Triathlon® TS Plus Inserts – K070095, K072221, K141056, K172326, K172634 ƒ Triathlon® Universal Baseplate – K053514, K141056, K172326 ƒ Triathlon® Femoral Distal Augments – K070095, K141056, K172326 ƒ Triathlon® Tibial Augments – K…	Stryker Orthopaedics	2006	2
†	K132624	Triathlon Tritanium Metal-Backed Patella	Stryker Orthopaedics	2013	1
†	K031729	Triathlon Posteriorly Stabilized (PS) Total Knee System	Howmedica Osteonics Corp.	2003	3
†	K983226	Osteonics X Cemented Hip Stem Series	Osteonics Corp.	1998	2
†	K153345	Stryker Orthopaedics Hip Systems Labeling Update	Stryker Orthopaedics	2016	1

Also cleared against K994207: 3 other devices →

What descends from it? (4)

3 later devices cite it directly; ranked here by how many devices descend from each in turn.

Number	Device	Applicant	Decided	Descendants
K230416	Triathlon® Hinge Knee System; Triathlon® Revision Insert X3®	Stryker	2023	3
K261898	Triathlon® Knee System; Triathlon® Hinge Knee System; Scorpio® Total Knee System	Howmedica Osteonics Corp. dba Stryker Orthopaedics	2026	0
K252898	Triathlon® Tritanium® Asymmetric Patella; Triathlon® Tritanium® Symmetric Patella…	Howmedica Osteonics Corp., Dba Stryker Orthopaedics	2025	0

Has anything in its family been recalled? (0 Class I)

Recalls of this device

Date	Class	Recall	Root cause	Reason
Jul 30, 2026	Class II	Z-3198-2026	Process change control	Affected devices were manufactured with Ultra High Molecular Weight Polyethylene (UHMWPE) raw material aged in excess of five years. Product has the potential for elevated levels of oxidation, which may result in increased wear, leading…

No ancestor or descendant has a Class I recall.

What does this lineage say?

The line of descent spans 29 years and passes through 6 companies; a new generation was cleared every 2.5 years on median.
47 of the 92 ancestors have a recall of any class.
Of its descendants, K230416 (Stryker, 2023) has gone furthest, with 3 descendants of its own.
3 other devices also cite its predicate K994207.

How does its category compare?

All KRO devices

KRO Prosthesis, Knee, Femorotibial, Constrained, Cemented, Metal/Polymer: FDA decisions, review times, recalls and adverse event reports over 20 years. 2023, this device’s year, is highlighted.

FDA decisions per year · KRO

3in 2025

2007high 6 (2015) · low 0 (2018)2026

2026 to Oct 25, outlined.

Median 510(k) review, days · KRO

56in 2025

2007high 244 (2019) · low 56 (2025)2026

Receipt to decision; years with fewer than 3 clearances left blank.

Recalls per year · KRO

14so far in 2026, the most since 2007

2007high 14 (2026) · low 0 (2010)2026

Class I (0 since 2007) Class II/III not classified

Adverse event reports per year · KRO

915in 2025

2007high 915 (2025) · low 37 (2007)2025

MAUDE reports naming product code KRO, 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	1	—	1	37
2008	3	126	3	44
2009	3	86	8	66
2010	1	—	0	110
2011	2	—	1	119
2012	2	—	1	173
2013	3	189	2	194
2014	2	—	0	406
2015	6	113	1	333
2016	3	148	5	369
2017	1	—	4	543
2018	0	—	1	614
2019	3	244	0	759
2020	1	—	0	749
2021	3	57	1	770
2022	1	—	0	892
2023	4	148	0	746
2024	3	87	0	855
2025	3	56	1	915
2026	1	—	14	—

What is it indicated for?

This Rotating Hinge Knee System is intended to be implanted with bone cement for the following

condition(s):

• There is destruction of the joint surfaces, with or without significant bone deformity.

• The cruciate and/or collateral ligaments do not stabilize the knee joint.

• The ligaments are inadequate and/or the musculature is weak. And/or

• Revision is required of a failed prosthesis where there has been gross instability, with or without bone loss or inadequate

soft tissue.

• And/or where segmental resection and replacement of the distal femur is required.

Indications for use as stated in the FDA summary.

https://510kreport.com/device/K223528 · printed Nov 4, 2026

Cite this page

510(k) Report. “K223528: Triathlon® Hinge Knee System.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 4, 2026. https://510kreport.com/device/K223528

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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