Patient conditions of non-inflammatory degenerative joint disease (NIDJD), e.g., 1. avascular necrosis, osteoarthritis and inflammatory joint disease (IJD), e.g., rheumatoid arthritis.
Those patients with failed previous surgery where pain, deformity, or dysfunction 2. persists.
Revision of previously failed arthroplasty. 3.

The Natural-Hip™ System Porous Stem with HA/CSTi™ is intended only for use without bone cement.

Device Description

The Natural-Hip System Porous Stem with HA/CSTi is a straight stem manufactured from Ti-6Al-4V alloy conforming to ASTM F-136. The stem is available in both a collared and collarless design. The proximal anterior surface of the stem employs anterior angulation or build-up to match the anatomic angulation of a natural femur. The superior portion of the stem has a built-in anteversion of nine degrees to match the anatomic anteversion of the femur. Circumferential hydroxylapatite coated Cancellous Structured Titanium™ (CSTi™) porous coating provides biological fixation in a cementless application. The distal portion of the Natural-Hip System Porous Stem with HA/CSTi employs ribs and flutes on the anterior and posterior sides to enhance cortical contact, thereby providing rotational stability to the hip stem. In addition, the distal portion of the stem has a flared coronal slot which reduces stiffness of the stem.

AI/ML Overview

This 510(k) submission describes a hip implant device, not an AI/ML-enabled medical device. Therefore, the information typically requested for AI/ML device acceptance criteria and studies (such as sample sizes for test and training sets, expert qualifications, ground truth methods, MRMC studies, and standalone performance) is not applicable in this context.

The document focuses on demonstrating substantial equivalence to predicate devices based on product description, diagnostic indications, and material composition. The FDA's letter (K970300) confirms this substantial equivalence but places limitations on labeling and promotional claims.

Here's an attempt to interpret the request within the context of a traditional medical device submission, focusing on "acceptance criteria" as related to the device's intended use and substantial equivalence:

1. Table of Acceptance Criteria and Reported Device Performance

For traditional medical devices like this hip implant, "acceptance criteria" are typically met by demonstrating that the device is substantially equivalent to legally marketed predicate devices in terms of intended use, technological characteristics, and safety and effectiveness. The "reported device performance" is essentially the determination of substantial equivalence by the FDA.

Criterion	Reported Device Performance (FDA's Determination)
Intended Use Equivalence: The device is intended for the same uses as legally marketed predicate devices.	Met: The Natural-Hip™ System Porous Stem with HA/CSTi™ is intended "to replace the anatomy of the femur in cases of total hip or hemi-hip replacement," and for "cementless (press-fit) application" for conditions like non-inflammatory degenerative joint disease (NIDJD), inflammatory joint disease (IJD), failed previous surgery, and revision. These indications are consistent with the predicate devices listed. (Refer to pages 1 and 5).
Technological Characteristics Equivalence: The device has similar technological features (e.g., design, materials, manufacturing).	Met: The device is described as "a straight stem manufactured from Ti-6Al-4V alloy conforming to ASTM F-136." It features "hydroxylapatite coated Cancellous Structured Titanium™ (CSTi™) porous coating" for biological fixation. The submission explicitly states the device is substantially equivalent to other Intermedics Orthopedics, Inc. products (Natural-Hip System Porous Stem, APR Universal Hip System) and competitive systems (Howmedica Precision Osteolock, Osteonics Omnifit with HA). The FDA's decision is "based on consideration of the specific design of stem and coating composition detailed in this application." (Refer to pages 1 and 2).
Safety and Effectiveness Equivalence: The device is as safe and effective as legally marketed predicate devices.	Met (with limitations): The FDA determined the device is substantially equivalent, allowing marketing. However, a significant limitation was placed: "You may not label or in any way promote these devices for enhanced clinical or radiographic performance, enhanced biological fixation and/or long-term stable fixation. The data presented support equivalence with no additional claims over a conventional porous-coated uncemented hip prosthesis (i.e., biological fixation, only)." This indicates the device meets the baseline safety and effectiveness of its predicates for biological fixation but cannot claim superiority or augmented performance. (Refer to page 2).

Study that Proves the Device Meets the Acceptance Criteria:

The "study" in this context is the 510(k) Premarket Notification itself, which presents information to the FDA to demonstrate substantial equivalence to predicate devices. This typically involves:

Comparison to Predicate Devices: A detailed comparison of the new device's intended use, technological characteristics (materials, design, manufacturing process), and performance data (if applicable, e.g., mechanical testing for implants) to one or more legally marketed predicate devices.
Performance Data (Non-Clinical): For an implant, this generally involves engineering tests, material characterization, and biocompatibility assessments to ensure the device performs as intended and is safe. The document implies such data were submitted, as the FDA based its decision on "the specific design of stem and coating composition." However, specific test results are not detailed in this summary.

Regarding your specific numbered points (which are more applicable to AI/ML devices):

Sample size used for the test set and the data provenance: Not applicable in the AI/ML sense. Mechanical testing or biocompatibility studies would use specific samples of the device and materials, but this isn't "test set" data for an algorithm.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. Ground truth for an implant isn't established by experts in this manner. Its performance is evaluated through engineering standards and clinical observation (post-market, often).
Adjudication method: Not applicable.
If a multi reader multi case (MRMC) comparative effectiveness study was done: Not applicable. This is not an imaging or diagnostic device that would involve human readers.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is a physical implant.
The type of ground truth used: For a physical implant, "ground truth" relates to its conformity to engineering specifications, material properties, biocompatibility, and mechanical performance under simulated physiological conditions. Ultimately, long-term clinical outcomes (post-market surveillance) provide the most significant "ground truth" regarding its effectiveness in patients.
The sample size for the training set: Not applicable.
How the ground truth for the training set was established: Not applicable.

In summary, for a traditional medical device like a hip implant, the "acceptance criteria" are fundamentally about demonstrating substantial equivalence to pre-existing, legally marketed devices. The "study" is the 510(k) submission itself, supported by non-clinical performance data (e.g., material properties, mechanical testing) rather than clinical studies or AI algorithm performance metrics.

Summary

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510(k) SUMMARY OF SAFETY AND EFFECTIVENESS

In accordance with the Food and Drug Administration Rule to implement provisions of the Safe Medical Devices Act of 1990 and in conformance with 21 CFR 807, this is to serve as a Summary of Safety and Effectiveness for the Natural-Hip™ System Porous Stem with HA/CSTi™.

Submitter:	Intermedics Orthopedics, Inc.9900 Spectrum DriveAustin, Texas 78717(512) 432-9900
Date:	January 20, 1997
Contact Person:	Jacquelyn HughesManager, Regulatory Affairs
Classification Name:	Hip joint metal/polymer/metal semi-constrained porous-coateduncemented prosthesis, 21 CFR 888.3358.
Common/Usual Name:	Biologically fixed total hip prosthesis, semi-constrained
Trade/Proprietary Name:	Natural-Hip™ System Porous Stem with HA/CSTi™

PRODUCT DESCRIPTION

This device is intended for use with the following previously cleared devices:

IOI metallic femoral bearing heads (510(k)s K905781 and K913060), 대통
l IOI Biolox Bearing Heads (510(k)s K923734, K942330),
통 Zirconia Bearing Heads (510(k) K944209),
체 IOI bipolar components (510(k)s K833404 and K873815).
배 IOI unipolar components (510(k)s K833403 and K934159),

000786

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IOI acetabular components (510(k)s K850793, K920955, K933203, K942406, I K941617, K954800, K955033 and K955739).

SPECIFIC DIAGNOSTIC INDICATIONS

The Natural-Hip System Porous Stem with HA/CSTi is intended to replace the anatomy of the femur in cases of total hip or hemi-hip replacement. In addition, the Natural-Hip System Porous Stem with HA/CSTi, like the predicate Intermedics Orthopedics, Inc. (IOI) and competitive hip stems, is intended for cementless (press-fit) application in cases of total hip or hemi-hip arthroplasty.

The general indications associated with the use of the Natural-Hip System Porous Stem with HA/CSTi in total hip arthroplasty include:

Patient conditions of noninflammatory degenerative joint disease (NIDJD), e.g., 1. avascular necrosis, osteoarthritis, and inflammatory joint disease (IJD), e.g., rheumatoid arthritis.
Those patients with failed previous surgery where pain, deformity, or dysfunction 2. persists.
Revision of previously failed hip arthroplasty 3.

Total hip replacements may be considered for younger patients if any unequivocal indication outweighs the risks associated with the age of the patient, and modified demands regarding activity and hip joint loading are assured. This includes severely crippled patients with multiple joint involvement. for whom an immediate need of hip mobility leads to an expectation of significant improvement in the quality of their lives.

The Natural-Hip System Porous Stem with HA/CSTi is intended only for use without bone cement in the United States. This device is intended for single use only.

SUBSTANTIAL EQUIVALENCE

The Natural-Hip System Porous Stem with HA/CSTi is substantially equivalent to the Natural-Hip System Porous Stem (Intermedics Orthopedics, Inc.), the APR Universal Hip System with Calcitite®-Coated CSTi (Intermedics, Inc.), the Howmedica Precision Osteolock, and the Osteonics Omnifit with HA.

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Image /page/2/Picture/1 description: The image shows the seal of the Department of Health & Human Services (HHS) of the United States of America. The seal features a circular design with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES · USA" arranged around the perimeter. Inside the circle is a stylized representation of a caduceus, a symbol often associated with medicine and healthcare.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Lori Kleinschrodt Holder, RAC Regulatory Affairs Specialist Sulzer Orthopedics Inc. - -9900 Spectrum Drive Austin, Texas 78717

JUL - 3 1997

Re : K970300 Natural-Hip™ System Porous Stem with HA/CSTi™ Requlatory Class: II Product Codes: LPH and MEH Dated: April 23, 1997 Received: April 25, 1997

Dear Ms. Holder:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments or to devices that have been reclassified in accordance with the provisions of the Federal Food, Druq, and Cosmetic Act (Act). This decision is based on consideration of the specific design of stem and coating composition detailed in this application. You may, therefore, market the device, subject to the general controls provisions of the Act and the following limitation:

You may not label or in any way promote these devices for enhanced clinical or radiographic performance, enhanced biological fixation and/or long-term stable fixation. The data presented support equivalence with no additional claims over a conventional porous-coated uncemented hip prosthesis (i.e., biological fixation, only).

Additional limitations for more specific claims of safety and effectiveness may be forthcoming. Should additional limitations be applied you will be contacted in writing to inform you of the additional labeling limitations.

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Paqe 2 - Lori Kleinschrodt Holder, RAC

The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

You may market your device under the above limitations as class II devices. These devices would be considered not substantially equivalent to a legally marketed predicate device if labeled with other intended uses and/or claims of safety or effectiveness. Any other intended uses or claims may cause the device to be classified into Class III under Section 513 (f) of the Act. Class III devices are required to have an approved premarket approval (PMA) application prior to marketing.

Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal Laws or Regulations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification immediately. An FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and permits your device to proceed to the market .

If you desire specific advice for your device on our labeling requlation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on

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Page 3 - Lori Kleinschrodt Holder, RAC

the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other qeneral information on your responsibilities under the Act may be ... obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

Celia M. Witten, Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radioloqical Health

Enclosure

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510(k) Number (if known): K970300

Device Name: Natural-Hip™ System Porous Stem with HA/CSTi™

Indications For Use:

Patient conditions of non-inflammatory degenerative joint disease (NIDJD), e.g., 1. avascular necrosis, osteoarthritis and inflammatory joint disease (IJD), e.g., rheumatoid arthritis.
Those patients with failed previous surgery where pain, deformity, or dysfunction 2. persists.
Revision of previously failed arthroplasty. 3.

The Natural-Hip™ System Porous Stem with HA/CSTi™ is intended only for use without bone cement.

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use

Over-The-Counter Use _________________________________________________________________________________________________________________________________________________________

(Optional Format 1-2-96)

Regulation Number and Section

§ 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

(a)
Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across the joint. This generic type of device has a femoral component made of a cobalt-chromium-molybdenum (Co-Cr-Mo) alloy or a titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high molecular weight polyethylene articulating bearing surface fixed in a metal shell made of Co-Cr-Mo or Ti-6Al-4V. The femoral stem and acetabular shell have a porous coating made of, in the case of Co-Cr-Mo substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average pore size between 100 and 1,000 microns, interconnecting porosity, and a porous coating thickness between 500 and 1,500 microns. The generic type of device has a design to achieve biological fixation to bone without the use of bone cement.(b)
Classification. Class II.