# K173890: GMK Sphere - Kinematic Alignment

- Pathway: 510(k) (Traditional)
- Applicant: Medacta International S.A.
- Decided: Aug 23, 2018 after 245 days
- Product code: JWH (Prosthesis, Knee, Patellofemorotibial, Semi-Constrained, Cemented, Polymer/Metal/Polymer)
- Device class: 2
- Regulation: 21 CFR 888.3560
- Recalls of this device: none
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 15 generations back to K941847 (1994). 179 ancestors in all.
6 later devices descend from it; 2 cite it directly.
0 of 185 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K121416: GMK Sphere, Medacta International (2012) Summary page 4.
- K140826: GMK Sphere Extension, Medacta International (2014) Summary page 4.
- K162035: GMK Sphere, Medacta International S.A. (2017) Summary page 4.
- K172524: Zimmer Persona Personalized Knee System, Zimmer, Inc. (2018). Cleared while this submission was under review Summary page 4.

## Most influential descendants
- K201343: Triathlon Total KneeSystem (2020), 3 descendants of its own
- K243574: Evolution® Total Knee Systems - Kinematic Alignment Instrumentation and Technique (2025), 1 descendant of its own
- K221850: GMK 3D Metal Tibial Tray (2022), 1 descendant of its own
- K253728: EVOLUTION® AM BIOFOAM® Tibial System (2026), 0 descendants of its own
- K261898: Triathlon® Knee System; Triathlon® Hinge Knee System; Scorpio® Total Knee System (2026), 0 descendants of its own

## Indications for use
The Evolis® GMK® knee prosthesis is designed for cemented use in total knee arthroplasty, if there is evidence of sufficient sound bone to seat and support the components. This knee replacement system is indicated in the following cases: * Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polyarthritis. * Avascular necrosis of femoral condyle. * Post traumatic loss of joint configuration. * Primary implantation failure. GMK Sphere can be implanted using a kinematic alignment approach. When a kinematic alignment approach is utilized, this knee replacement system is indicated in the following cases: * Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polyarthritis. * Collagen disorders, and/or avascular necrosis of the femoral condyle. » Moderate valgus, varus, or flexion deformities. Tibial wedges cemented are to be attached to the tibial baseplate with both the fixing cylinders and bone cement. The screwed tibial augments are for screwed fixation to the tibial baseplate. In case a semi-constrained liner is used, an extension stem must be implanted both on the tibial and on the femoral components. In case a GMK Revision tibial tray is used, an extension stem must be implanted.

Source page: https://510kreport.com/device/K173890
Methodology: https://510kreport.com/methodology