# K252303: Stem Extension Line (USTAR II System)

- Pathway: 510(k) (Special)
- Applicant: United Orthopedic Corporation
- Decided: Aug 22, 2025 after 29 days
- Product code: KRO (Prosthesis, Knee, Femorotibial, Constrained, Cemented, Metal/Polymer)
- Device class: 2
- Regulation: 21 CFR 888.3510
- Recalls of this device: none
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 8 generations back to K921308 (1994). 54 ancestors in all.
No later device cites it as a predicate yet.
0 of 55 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K190100: USTAR II System, United Orthopedic Corporation (2019) Summary page 5.

## Indications for use
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.

Source page: https://510kreport.com/device/K252303
Methodology: https://510kreport.com/methodology