# K955778: Natural-Knee II Unicompartmentalknee System

- Pathway: 510(k) (Traditional)
- Applicant: Intermedics Orthopedics
- Decided: Mar 8, 1996 after 79 days
- Product code: HRY (Prosthesis, Knee, Femorotibial, Semi-Constrained, Cemented, Metal/Polymer)
- Device class: 2
- Regulation: 21 CFR 888.3530
- Recalls of this device: 1 (0 Class I)
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
No predicates in its family tree.
22 later devices descend from it; 2 cite it directly.
0 of 23 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- None. The FDA summary names its predicate without a number.
- (no number) Howmedica PCA Unicompartmental Knee System: named in the summary without a submission number
- (no number) DePuy Synatomic Unicondylar Knee: named in the summary without a submission number
- (no number) Wright Medical Whiteside Ortholoc II Unicondylar Knee System: named in the summary without a submission number
- (no number) Osteonics Omnifit SCR Knee System: named in the summary without a submission number
- (no number) Zimmer Miller/Galante Unicompartmental Knee System: named in the summary without a submission number
- (no number) Kirschner Performance Unicompartmental Knee: named in the summary without a submission number
- (no number) Smith & Nephew Richards Genesis Unicompartmental Knee: named in the summary without a submission number
- (no number) Johnson & Johnson PFC Unicompartmental Knee System: named in the summary without a submission number

## Most influential descendants
- K033810: Natural-Knee II Unicompartmental Knee System (2004), 20 descendants of its own
- K133811: Restoris Porous Partial Knee System (2014), 19 descendants of its own
- K163700: Bodycad Unicompartmental Knee System (2017), 8 descendants of its own
- K181302: Bodycad Unicompartmental Knee System (2019), 7 descendants of its own
- K190439: Engage™ Partial Knee System (2019), 5 descendants of its own

## Recalls of this device
- Feb 25, 2014 · Class II · Z-1251-2014: A complaint was received for a discolored All Poly Tibia. Root cause analysis found that the discoloration was the result of free radical oxidation. The oxidation process was advanced prematurely as a

## Indications for use
The Natural-Knee II - Unicompartmental Knee Prosthesis is intended for resurfacing of one side of the knee joint.

Source page: https://510kreport.com/device/K955778
Methodology: https://510kreport.com/methodology