FDA 510(k) Search - By Innolitics (SaMD and AI Experts)

Metastatic tumor (i.e. osteosarcoma, chondrosarcoma, giant cell tumor or osteoma) where massive resection and transplantation are needed.
Severe knee joint damage resulting from trauma where massive resection and transplantation are needed.
Non-inflammatory degenerative joint disease such as avascular necrosis, osteoarthritis, or traumatic arthritis.
Revision of previously failed total joint arthroplasty, osteotomy, or arthrodesis.
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 PSC and intended for cementless use only.

Device Description

"United" USTAR II System is used for patients who present large quantity of bone loss and deformity associated with previous failed arthroplasty, ligament deficiencies, tumor resection, or trauma and may require a further operation or reconstruction. The USTAR II System includes implanted arthroplasty components of both the USTAR II Knee System and USTAR II Hip System.

For the subject device, it's an extension line of 510(K) cleared device USTAR II System (K190100), which introduces two new variations:

Cemented curved stem, RHS, non-coated: diameter 17×200 mm
Tibial stem: stem length from 30mm to 150 mm by stem diameter from diameter 9 to diameter 24

The compatibility of cemented curved stem, RHS, non-coated and tibial stem is same as that of the 510(k) cleared USTAR II system (K190100).

Cemented Curved Stem, RHS, non-coated is an extension in terms of sizes to 510 (k) cleared device USTAR II system (K190100). Its design, materials, geometrical characteristic, locking mechanism, and manufacturing process are identical to that of the 510(k) cleared Cemented Curved Stem, RHS, non-coated.

Tibial stem's design, materials, geometrical characteristic, locking mechanism, and manufacturing process are identical to that of the 510(k) cleared Tibial Stem while the only difference lies in its specification

AI/ML Overview

Please note: The provided FDA 510(k) clearance letter and summary describe a medical device (Stem Extension Line for the USTAR II System), which is an orthopedic implant. This document does not describe an AI/Software as a Medical Device (SaMD).

Therefore, the requested information about "acceptance criteria and the study that proves the device meets the acceptance criteria" in the context of an AI/SaMD, including details like "number of experts used to establish ground truth," "adjudication method," "MRMC study," "standalone performance," "training set size," and "ground truth establishment for training set," are not applicable to this type of device submission.

The provided text focuses on the mechanical and design equivalence of the new implant variations to a previously cleared predicate device. The "study" mentioned refers to non-clinical mechanical analyses.

Below is an interpretation of the requested points adapted to the context of this orthopedic implant:

Acceptance Criteria and Study for the Stem Extension Line (USTAR II System)

1. Table of Acceptance Criteria and Reported Device Performance

For this orthopedic implant, the acceptance criteria are based on established international standards for the mechanical performance of prosthetic components and demonstrate equivalence to the predicate device.

Acceptance Criteria Category	Specific Test Standard / Requirement	Device Performance (Reported Outcome)
Stem Fatigue Analysis	ISO 7206-4 (Implants for surgery — Partial and total hip joint prostheses — Part 4: Determination of endurance properties and performance of stemmed femoral components)	Met required acceptance criteria. (Implied to be comparable to or better than the predicate device under the specified test conditions).
Mechanical Strength of Tibial Baseplate	ASTM F1800 (Standard Practice for Testing of the Cement-Stem Interface for Femoral Hip Prosthesis) and ISO 21536:2023 (Implants for surgery — Joint replacement prostheses — Specific requirements for knee joint prostheses)	Met required acceptance criteria. (Implied to be comparable to or better than the predicate device under the specified test conditions).
Design, Materials, Geometrical Characteristics, Locking Mechanism, Manufacturing Process	Identical to 510(k) cleared USTAR II system (K190100).	Confirmed identical.
Safety and Effectiveness	Equivalent to predicate devices based on the same analysis method applied in previous submission; no new risks identified.	Established equivalent safety and effectiveness.

2. Sample size used for the test set and the data provenance

Sample Size for Test Set: Not explicitly stated as a number of physical implants or test articles in the provided summary. For mechanical testing, typically a defined number of test samples are used per standard, but the specific quantity is not given here.
Data Provenance: The studies are non-clinical mechanical analyses performed to international standards (ISO, ASTM). The origin of the "data" itself would be the laboratory where these mechanical tests were conducted. It's a prospective design verification process, not a retrospective or prospective clinical study with human data.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not Applicable. This is a non-clinical, mechanical device clearance. "Ground truth" in the context of clinical interpretation or diagnosis by experts (e.g., radiologists) is not relevant here. Ground truth is established by standardized material properties, engineering specifications, and mechanical test results per the referenced ISO and ASTM standards. Experts involved would be engineers and material scientists responsible for the design, testing, and analysis, ensuring compliance with manufacturing and performance standards.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not Applicable. Adjudication methods like 2+1 or 3+1 typically refer to consensus readings or evaluations by multiple human experts in studies involving subjective interpretation (e.g., imaging, clinical outcomes). For mechanical testing, the results are quantitative and objective, measured against predefined acceptance criteria from engineering standards.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

Not Applicable. MRMC studies are specific to evaluating the clinical performance of diagnostic aids, particularly those involving human interpretation, and are commonly used for AI/ML in medical imaging. This submission concerns the mechanical safety and functionality of an orthopedic implant. No human reader involvement or AI assistance is relevant.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not Applicable. "Standalone performance" refers to the performance of an AI algorithm independent of human input. This device is a physical orthopedic implant, not an algorithm or software.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The "ground truth" for this type of device is based on engineering standards and specifications. This includes:
- Material properties: Verifying components meet specified material strengths and compositions.
- Geometric tolerances: Ensuring dimensions align with design specifications.
- Mechanical performance: Demonstrating the implant can withstand anticipated loads and stresses as defined by the ISO and ASTM test standards (e.g., fatigue life, static strength).
- Equivalence to Predicate Device: The primary "ground truth" is that the new variations perform equivalently to or better than the already cleared predicate device under the same test conditions.

8. The sample size for the training set

Not Applicable. This is not an AI/ML device where a "training set" of data is used to develop an algorithm. The "design" and "manufacturing process" are based on established engineering principles and prior validated designs (the predicate device).

9. How the ground truth for the training set was established

Not Applicable. As there is no "training set" in the context of an AI/ML algorithm for this physical device, there is no method for establishing its "ground truth." The design and manufacturing processes are validated through engineering analyses and quality control processes to meet the required specifications and standards.

Summary

Regulation Number and Section

§ 888.3510 Knee joint femorotibial metal/polymer constrained cemented prosthesis.

(a)
Identification. A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device limits translation or rotation in one or more planes and has components that are linked together or affined. This generic type of device includes prostheses composed of a ball-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a ball at the head of a column rising from the stemmed tibial component. The ball, the column, the tibial plateau, and the stem for fixation of the tibial component are made of an alloy, such as cobalt-chromium-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the femoral component's flat outer surface. The flat outer surface of the tibial component abuts both a reciprocal flat surface within the cavity of the femoral component and flanges on the femoral component designed to prevent distal displacement. The stem of the femoral component is made of an alloy, such as cobalt-chromium-molybdenum, but the socket of the component is made of ultra-high molecular weight polyethylene. The femoral component has metallic runners which align with the ultra-high molecular weight polyethylene tracks that press-fit into the metallic tibial component. The generic class also includes devices whose upper and lower components are linked with a solid bolt passing through a journal bearing of greater radius, permitting some rotation in the transverse plane, a minimal arc of abduction/adduction. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.