510(k) Report

510(k) · Cleared

Recalled · Class II · 2026

USTAR II System

K190100510(k) TraditionalCleared Sep 23, 2019244-day reviewClass II21 CFR 888.3510Recalls 5

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

United Orthopedic Corporation · KRO Prosthesis, Knee, Femorotibial, Constrained, Cemented, Metal/Polymer

Cleared on Sep 23, 2019 as substantially equivalent to K082424 (United Orthopedic Corp., 2008) and 8 other predicates after a 244-day review. Its family tree reaches back 7 generations to 1994. 2 later devices descend from it. It has been recalled 5 times.

Decided
Sep 23, 2019
Review
244 days
Class
Class II
Product code
KRO
Recalls
5
Predicates
9

Its longest line of descent runs back 7 generations to K921308 (1994). 53 ancestors in all, the oldest K864671 (1987). 2 later devices descend from it, 2 citing it directly.

Other ancestors, by year clearedDescendants, by year cleared 2013: 1 other ancestor2011: 1 other ancestor2010: 3 other ancestors2008: 1 other ancestor2007: 1 other ancestor2005: 4 other ancestors2002: 3 other ancestors2000: 6 other ancestors2006: 1 other ancestor1997: 2 other ancestors1996: 7 other ancestors1987: 1 other ancestor2004: 1 other ancestor2003: 2 other ancestors2001: 1 other ancestor1999: 1 other ancestor1995: 7 other ancestors1992: 1 other ancestor1994: 2 other ancestors2025: 2 descendants clearedReference device: K123550 · Utf Stem, Reduced · United Orthopedic Corporation · 2013Reference device: K152530 · UCP Stem · United Orthopedic Corporation · 2016Reference device: K111546 · U2 Hip System · United Orthopedic Corp. · 2011 · recalledReference device: K023087 · Global Modular Replacement System (GMRS) · Howmedica Osteonics Corp. · 2002 · recalledReference device: K100048 · E1 Antioxidant Infused Technology · Biomet Manufacturing Corp · 2010K921308 · HG Multilock Hip Prosthesis W/ TI-Nidium · Zimmer, Inc. · 1994 · recalledK972893 · Partnership Revision Femoral Stems · Howmedica Corp. · 1997K983404 · Type 3 Femoral Components · Howmedica Corp. · 1998 · recalledK013106 · 2 Piece Modular Hip Stem · Howmedica Osteonics Corp. · 2002 · recalledK022549 · Restoration Modular System · Howmedica Osteonics Corp. · 2002 · recalledK090757 · Biomet Modular Femoral Revision System · Biomet, Inc. · 2009 · recalledK130063 · Arcos Trochanter Button · Biomet, Inc. · 20131990200020102020
Other ancestors, by generationDescendants, by generation 1 generation back: 8 other ancestors2 generations back: 9 other ancestors3 generations back: 11 other ancestors4 generations back: 9 other ancestors5 generations back: 9 other ancestors 1 generation forward: 2 descendants K130063 · Arcos Trochanter Button · Biomet, Inc. · 2013K090757 · Biomet Modular Femoral Revision System · Biomet, Inc. · 2009 · recalledK022549 · Restoration Modular System · Howmedica Osteonics Corp. · 2002 · recalledK013106 · 2 Piece Modular Hip Stem · Howmedica Osteonics Corp. · 2002 · recalledK983404 · Type 3 Femoral Components · Howmedica Corp. · 1998 · recalledK972893 · Partnership Revision Femoral Stems · Howmedica Corp. · 1997K921308 · HG Multilock Hip Prosthesis W/ TI-Nidium · Zimmer, Inc. · 1994 · recalled−50
  1. Root · 7 generations backK921308 HG Multilock Hip Prosthesis W/ TI-NidiumZimmer, Inc. · 1994 · Recalled
  2. 6 generations backK972893 Partnership Revision Femoral StemsHowmedica Corp. · 1997
  3. 5 generations backK983404 Type 3 Femoral ComponentsHowmedica Corp. · 1998 · Recalled
  4. 4 generations backK013106 2 Piece Modular Hip StemHowmedica Osteonics Corp. · 2002 · Recalled
  5. 3 generations backK022549 Restoration Modular SystemHowmedica Osteonics Corp. · 2002 · Recalled
  6. 2 generations backK090757 Biomet Modular Femoral Revision SystemBiomet, Inc. · 2009 · Recalled
  7. 1 generation backK130063 Arcos Trochanter ButtonBiomet, Inc. · 2013
  8. This deviceK190100 USTAR II SystemUnited Orthopedic Corporation · 2019
  9. Descendant · cites it directly · 0 of its ownK252303 Stem Extension Line (USTAR II System)United Orthopedic Corporation · 2025
  10. Descendant · cites it directly · 0 of its ownK243656 U2 Total Knee System – PF+ Patella; USTAR II System– PF+ PatellaUnited Orthopedic Corporation · 2025

Most influential descendants

Showing 2 of 2 · See all
  • K252303Stem Extension Line (USTAR II System)United Orthopedic Corporation · 2025 · cites it directly0descendants
  • K243656U2 Total Knee System – PF+ Patella; USTAR II System– PF+ PatellaUnited Orthopedic Corporation · 2025 · cites it directly0descendants
View FIG. 1 as a table

Line of descent and top descendants

GenerationNumberDeviceApplicantDecidedRecalls
−7K921308HG Multilock Hip Prosthesis W/ TI-NidiumZimmer, Inc.19941
−6K972893Partnership Revision Femoral StemsHowmedica Corp.1997—
−5K983404Type 3 Femoral ComponentsHowmedica Corp.19981
−4K0131062 Piece Modular Hip StemHowmedica Osteonics Corp.200237
−3K022549Restoration Modular SystemHowmedica Osteonics Corp.20023
−2K090757Biomet Modular Femoral Revision SystemBiomet, Inc.200918
−1K130063Arcos Trochanter ButtonBiomet, Inc.2013—
0 (this device)K190100USTAR II SystemUnited Orthopedic Corporation2019—
+1K252303Stem Extension Line (USTAR II System)United Orthopedic Corporation2025—
+1K243656U2 Total Knee System – PF+ Patella; USTAR II System– PF+ PatellaUnited Orthopedic Corporation2025—

Other ancestors by year cleared

Year clearedDevicesWith a Class I recall
198710
199210
199420
199570
199670
199720
199910
200060
200110
200230
200320
200410
200540
200610
200710
200810
201030
201110
201310

Descendants by year cleared

Year clearedDevicesWith a Class I recall
202520
FIG. 1 — Lineage of K190100, 1994–2025Source: FDA 510(k) summaries, read by 510(k) Report · How lineage is built

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Notable FDA decisions, review times and new Class I recalls. See an issue.

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. #1 K251665 Triathlon® Hinge Knee Systemscore 19.0 · 12 generations · no Class I recall
  2. #2 Held for the reportin the report
  3. #3 Held for the reportin the report
Get a 510(k) Report

What was it cleared against? (9)

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.

TypeNumberDeviceApplicantDecidedRecalls
*K082424United U2 Total Knee System
Summary page 5
…CFR 888.3358) Regulatory Class Class II Product Code(s) KRO, LPH, LWJ, KWL Predicate Device(s) 1. “United” U2 Total Knee System – PSA Type (K082424, K100981, K122183) 2. “Zimmer” NexGen® Complete Knee Solution Rotating…
United Orthopedic Corp.20082
*K100981United Stem, Psa Type
Summary page 5
…Class II Product Code(s) KRO, LPH, LWJ, KWL Predicate Device(s) 1. “United” U2 Total Knee System – PSA Type (K082424, K100981, K122183) 2. “Zimmer” NexGen® Complete Knee Solution Rotating Hinge Knee (K…
United Orthopedic Corp.2010—
*K122183Augment and Screw, Psa Type
Summary page 5
…ss II Product Code(s) KRO, LPH, LWJ, KWL Predicate Device(s) 1. “United” U2 Total Knee System – PSA Type (K082424, K100981, K122183) 2. “Zimmer” NexGen® Complete Knee Solution Rotating Hinge Knee (K013385)…
United Orthopedic Corp.2013—
*K013385Nexgen Complete Knee Solution Rotatng Hinge Knee
Summary page 5
…82424, K100981, K122183) 2. “Zimmer” NexGen® Complete Knee Solution Rotating Hinge Knee (K013385) 3. “Zimmer” Zimmer® Segmental System (K070978, K110940)…
Zimmer, Inc.20022
*K070978Zimmer Segmental System
Summary page 5
…2. “Zimmer” NexGen® Complete Knee Solution Rotating Hinge Knee (K013385) 3. “Zimmer” Zimmer® Segmental System (K070978, K110940) K190100 - Page 2 of…
Zimmer, Inc.20076
*K110940Zimmer Segment System Trabecular Metal Proximal Tibial Component, Trabecular Metal…
Summary page 5
…ee Solution Rotating Hinge Knee (K013385) 3. “Zimmer” Zimmer® Segmental System (K070978, K110940) K190100 - Page 2 of 6 4. “Biom…
Zimmer, Inc.2011—
*K002757Oncology Salvage System
Summary page 6
…K110940) K190100 - Page 2 of 6 4. “Biomet” Orthopaedic Salvage System (K002757, K052685) 5. “Zimmer” Arcos Modular Femoral Revision System (K1…
Biomet, Inc.200014
*K052685Orthopedic Salvage System- Oss
Summary page 6
…K190100 - Page 2 of 6 4. “Biomet” Orthopaedic Salvage System (K002757, K052685) 5. “Zimmer” Arcos Modular Femoral Revision System (K130063) Reference Device(s) 1.…
Biomet, Inc.20052
*K130063Arcos Trochanter Button
Summary page 6
…iomet” Orthopaedic Salvage System (K002757, K052685) 5. “Zimmer” Arcos Modular Femoral Revision System (K130063) Reference Device(s) 1. “United” UTF Stem, reduced, Ti plasma spray (K123550) 2.…
Biomet, Inc.2013—
†K123550Utf Stem, ReducedUnited Orthopedic Corporation2013—
†K152530UCP StemUnited Orthopedic Corporation2016—
†K111546U2 Hip SystemUnited Orthopedic Corp.20111
†K023087Global Modular Replacement System (GMRS)Howmedica Osteonics Corp.20022
†K100048E1 Antioxidant Infused TechnologyBiomet Manufacturing Corp2010—

Also cleared against K082424: 8 other devices →

What descends from it? (2)

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

NumberDeviceApplicantDecidedDescendants
K252303Stem Extension Line (USTAR II System)United Orthopedic Corporation20250
K243656U2 Total Knee System – PF+ Patella; USTAR II System– PF+ PatellaUnited Orthopedic Corporation20250

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

Recalls of this device

DateClassRecallRoot causeReason
May 20, 2026Class IIZ-2884-2026Process designDue to an incomplete process of the component screw by a subcontractor which prevents the properly assembling of stem trail.
Jan 3, 2024Class IIZ-1216-2024Nonconforming Material/ComponentTheir is a potential that the implant curved stem may be oriented incorrectly.
Jan 3, 2024Class IIZ-1217-2024Nonconforming Material/ComponentTheir is a potential that the implant curved stem may be oriented incorrectly.
Jan 3, 2024Class IIZ-1215-2024Nonconforming Material/ComponentTheir is a potential that the implant curved stem may be oriented incorrectly.
Aug 27, 2021Class IIZ-0110-2022Device DesignDue to product not meeting specification for concentricity and failing to meet requirements of dynamic fatigue testing.

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 3.6 years on median.
  • 30 of the 53 ancestors have a recall of any class.
  • Of its descendants, K252303 (United Orthopedic Corporation, 2025) has gone furthest, with 0 descendants of its own.
  • 8 other devices also cite its predicate K082424.

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. 2019, this device’s year, is highlighted.

FDA decisions per year · KRO

3in 2025

2007: 12008: 32009: 32010: 12011: 22012: 22013: 32014: 22015: 62016: 32017: 12019: 32020: 12021: 32022: 12023: 42024: 32025: 32026 (partial year): 1
2007high 6 (2015) · low 0 (2018)2026

2026 to Oct 25, outlined.

Median 510(k) review, days · KRO

56in 2025

2008: 126 days median2009: 86 days median2013: 189 days median2015: 113 days median2016: 148 days median2019: 244 days median2021: 57 days median2023: 148 days median2024: 87 days median2025: 56 days median
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

2007: 12008: 32009: 82011: 12012: 12013: 22015: 12016: 52017: 42018: 12021: 12025: 12026 (partial year): 14
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

2007: 372008: 442009: 662010: 1102011: 1192012: 1732013: 1942014: 4062015: 3332016: 3692017: 5432018: 6142019: 7592020: 7492021: 7702022: 8922023: 7462024: 8552025: 915
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
YearDecisionsMedian 510(k) review, daysRecalls (Class I)MAUDE reports
20071—137
20083126344
2009386866
20101—0110
20112—1119
20122—1173
201331892194
20142—0406
201561131333
201631485369
20171—4543
20180—1614
201932440759
20201—0749
20213571770
20221—0892
202341480746
20243870855
20253561915
20261—14—

What is it indicated for?

USTAR II Knee System 1. Metastatic tumor (i.e. osteosarcoma, chondrosarcoma, giant cell tumor or osteoma) where massive resection and transplantation are needed. 2. Severe knee joint damage resulting from trauma where massive resection and transplantation are needed. 3. Non-inflammatory degenerative joint disease such as avascular necrosis, osteoarthritis, or traumatic arthritis. 4. Revision of previously failed total joint arthroplasty, osteotomy, or…

Read the full statement (328 words)

USTAR II Knee System

1. Metastatic tumor (i.e. osteosarcoma, chondrosarcoma, giant cell tumor or osteoma) where massive resection and transplantation are needed.

2. Severe knee joint damage resulting from trauma where massive resection and transplantation are needed.

3. Non-inflammatory degenerative joint disease such as avascular necrosis, osteoarthritis, or traumatic arthritis.

4. Revision of previously failed total joint arthroplasty, osteotomy, or arthrodesis.

5. Joint instability resulting from excessive bone resection.

For Femoral component, Hinged/ Tibial baseplate, Hinged/ Cemented tibial stem/ Cemented Straight stem, RHS, non coated/ Cemented Curved stem, RHS, non coated/ Cemented Straight stem, RHS/ Cemented Curved stem, RHS/ Tibial Augment: These devices are single use implant and intended for cemented use only.

For Distal Femoral Component, RHS/ Proximal Tibial Component, RHS/ Tibial stem/ Segment Part, RHS/ Segment Part, RHS, Bridge: These devices are single use implant and intended for cementless use only.

USTAR II Knee System, Stem

1. Metastatic tumor (i.e. osteosarcoma, chondrosarcoma, giant cell tumor or osteoma) resulting from trauma where massive resection and transplantation are needed.

2. Severe knee joint damage resulting from trauma where massive resection and transplantation are needed.

3. Non-inflammatory degenerative joint disease such as avascular necrosis, osteoarthritis, or traumatic arthritis.

4. Correction for revision of unsuccessful osteotomy, arthrodesis, or failure of previous joint replacement.

5. Joint instability resulting from excessive bone resection.

Cemented Tibial Stem is a single use implant and intended for cemented use only.

Tibial Stem is a single use implant and intended for cementless use only.

USTAR II Hip System

1. Metastatic tumor (i.e. osteosarcoma, chondrosarcoma, giant cell tumor or osteoma) where massive resection and transplantation are needed.

2. Severe knee joint damage resulting from trauma where massive resection and transplantation are needed.

3. Non-inflammatory degenerative joint disease such as avascular necrosis, osteoarthritis, or traumatic arthritis.

4. Revision of previously failed total joint arthroplasty, osteotomy, or arthrodesis.

5. Joint instability resulting from excessive bone resection.

This device is a single use implant and intended for cementless use only.

Indications for use as stated in the FDA summary.

Also cleared against K082424

8 other devices cite the same predicate.

  • K252725Stem Extension Line (U2 Total Knee System—PSA Type)United Orthopedic Corporation · 2025
  • K210695CPM Medical Consultants Tibial Revision Knee SystemCpm Medical Consultants, LLC · 2021
  • K161705U2 Total Knee System E-XPE productsUnited Orthopedic Corporation · 2017
  • K161360U2 Total Knee System, PSA Tibial InsertUnited Orthopedic Corporation · 2017
  • K131864U2 Tibial Baseplate- Cma Type, Tibial Insert and AugmentUnited Orthopedic Corporation · 2014
  • K131116U2 Total Knee System - Psa Type, Offset Stem AdapterUnited Orthopedic Corporation · 2013

More from United Orthopedic Corporation

41 FDA decisions under this applicant name. See the company

  • K253948Momentum Acetabular Cup SystemUnited Orthopedic Corporation · 2026
  • K252725Stem Extension Line (U2 Total Knee System—PSA Type)United Orthopedic Corporation · 2025
  • K252303Stem Extension Line (USTAR II System)United Orthopedic Corporation · 2025
  • K243656U2 Total Knee System – PF+ Patella; USTAR II System– PF+ PatellaUnited Orthopedic Corporation · 2025
  • K242315Resolve Modular Revision Hip StemUnited Orthopedic Corporation · 2025

Recent decisions in KRO

The KRO category page

  • K261898Triathlon® Knee System; Triathlon® Hinge Knee System; Scorpio® Total Knee SystemHowmedica Osteonics Corp. dba Stryker Orthopaedics · 2026
  • K252898Triathlon® Tritanium® Asymmetric Patella; Triathlon® Tritanium® Symmetric Patella; Triathlon® Symmetric…Howmedica Osteonics Corp., Dba Stryker Orthopaedics · 20251 recall
  • K252303Stem Extension Line (USTAR II System)United Orthopedic Corporation · 2025
  • K251665Triathlon® Hinge Knee SystemHowmedica Osteonics Corp., Dba Stryker Orthopaedics · 2025
  • K242871ATTUNE™ Revision Hinge KneeDepuy Ireland UC · 202411 recalls

https://510kreport.com/device/K190100 · printed Nov 6, 2026

Cite this page

510(k) Report. “K190100: USTAR II System.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K190100

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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