Cleared Special

K252303 - Stem Extension Line (USTAR II System) (FDA 510(k) Clearance)

Class II Orthopedic device cleared through the Special 510(k) pathway - typically does not require clinical trials.

K252303 · United Orthopedic Corporation · Orthopedic device
Download Printable Device Report (PDF)
Optimized for regulatory review, auditing and printing
Aug 2025
Decision
29d
Days
Class 2
Risk

K252303 is an FDA 510(k) clearance for the Stem Extension Line (USTAR II System). Classified as Prosthesis, Knee, Femorotibial, Constrained, Cemented, Metal/polymer (product code KRO), Class II - Special Controls.

Submitted by United Orthopedic Corporation (Kaohsiung, TW). The FDA issued a Cleared decision on August 22, 2025 after a review of 29 days - a notably fast clearance cycle.

This device falls under the Orthopedic FDA review panel, regulated under 21 CFR 888.3510 - the FDA orthopedic device regulatory framework. As a Special 510(k), this submission covers a manufacturer modification to an existing cleared device rather than a new device introduction.

Device pattern: Iterative device modification. Low regulatory complexity profile. This Special 510(k) clearance confirms that the manufacturer's modifications remained within the established regulatory envelope of the original cleared device.

View all United Orthopedic Corporation devices

Submission Details

510(k) Number K252303 FDA.gov
FDA Decision Cleared Substantially Equivalent - Traditional 510(k) (SESE)
Date Received July 24, 2025
Decision Date August 22, 2025
Days to Decision 29 days
Submission Type Special
Review Panel Orthopedic (OR)
Summary Summary PDF
Third-party Review No - reviewed directly by FDA
Combination Product No
PCCP Authorized No
Regulatory Context
Review time vs. panel average
93d faster than avg
Panel avg: 122d · This submission: 29d
Pathway characteristics
Modification to existing cleared device.

Device Classification

Product Code KRO Prosthesis, Knee, Femorotibial, Constrained, Cemented, Metal/polymer
Device Class Class 2 - Special Controls
CFR Regulation 21 CFR 888.3510
What this classification means

Class II devices require demonstration of substantial equivalence to a legally marketed predicate device. This pathway does not require clinical trials - it relies on engineering equivalence and performance data. Most Orthopedic devices follow this clearance model.

Regulatory Peers - KRO Prosthesis, Knee, Femorotibial, Constrained, Cemented, Metal/polymer

All 85
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K230563 · Microport Orthopedics, Inc. · Sep 2023