# K100981: United Stem, Psa Type

- Pathway: 510(k) (Special)
- Applicant: United Orthopedic Corp.
- Decided: Jun 14, 2010 after 66 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: 3 generations back to K962137 (1996). 10 ancestors in all.
3 later devices descend from it; 1 cites it directly.
0 of 14 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K082424: United U2 Total Knee System, United Orthopedic Corp. (2008) Summary page 1.
- K864671: Anatomic Modular Knee (Amk) System, Depuy, Inc. (1987) Summary page 1.
- K043440: Smith & Nephew, Inc. Revision Knee System, Smith & Nephew, Inc. (2005) Summary page 1.

## Most influential descendants
- K190100: USTAR II System (2019), 2 descendants of its own
- K252303: Stem Extension Line (USTAR II System) (2025), 0 descendants of its own
- K243656: U2 Total Knee System – PF+ Patella; USTAR II System– PF+ Patella (2025), 0 descendants of its own

## Indications for use
Stem - PSA Type is included in U2 Total Knee System-PSA type. U2 Total Knee System-PSA type is indicated for use in skeletally mature patients with severe knee pain and disability undergoing surgery for knee arthroplasty due to rheumatoid arthritis, osteoarthritis, primary and secondary traumatic arthritis, polyarthritis, collagen disorddrs, avascular necrosis of the femoral condyle or pseudogout, posttraumnatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior pateltectomy, moderate valgus, varus, or flexion contraction. This device is intended for use in patients who require augmentation and/or stem extensions due to inadequate bone stock and/or require constrained stabilization for tibiofemoral joint due to soft tissue imbalance. U2 Total Knee System-PSA type isdesigned for cemented use only.

Source page: https://510kreport.com/device/K100981
Methodology: https://510kreport.com/methodology