NATURAL-KNEE II CONSTRAINED KNEE SYSTEM

K973412 · Sulzer Orthopedics, Inc. · JWH · Dec 8, 1997 · Orthopedic

Device Facts

• Record ID: K973412
• Device Name: NATURAL-KNEE II CONSTRAINED KNEE SYSTEM
• Applicant: Sulzer Orthopedics, Inc.
• Product Code: JWH · Orthopedic
• Decision Date: Dec 8, 1997
• Decision: SN
• Submission Type: Traditional
• Regulation: 21 CFR 888.3560
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

The Natural-Knee™ II Constrained Knee System is intended use in the following diagnostic indications : - 1) Patient conditions, including but not limited to, inflammatory degenerative joint disease (e.g., rheumatoid arthritis) and noninflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis). - 2) Correctable valgus-varus deformity and moderate flexion contracture. - 3) Those patients with failed previous surgery where pain, deformity, or dysfunction persist. - 4) Revision of previously failed knee arthroplasty. The Natural-Knee™ II Constrained Knee System is intended only for use with bone cement in the United States. Uncemented use of the Natural-Knee™ II Constrained Knee System is considered to be investigational in the United States. This device is intended for single use only.

Device Story

Non-porous total knee replacement system; semiconstrained design; used for primary and revision knee surgeries. Components: CoCr femoral component (anatomic/asymmetrical), Ti-4A1-6V tibial baseplate, UHMWPe tibial insert. Includes CoCr pin for posterior stability; compatible with revision stems, femoral/tibial spacers, and patellar components. Used by orthopedic surgeons in clinical settings. Device replaces knee joint surfaces; provides stability in absence of posterior cruciate ligament; requires intact collateral ligaments. Fixed to bone using acrylic bone cement. Benefits: restores joint function, reduces pain, corrects deformity in patients with failed prior arthroplasty or degenerative disease.

Clinical Evidence

No clinical data provided. Bench testing only.

Technological Characteristics

Materials: Cobalt chromium/molybdenum (CoCr) alloy (femoral component, spacers, pin), Titanium alloy (Ti-4A1-6V) (tibial baseplate), Ultra High Molecular Weight Polyethylene (UHMWPe) (tibial insert). Semiconstrained design; anatomic/asymmetrical geometry. Fixation: Cemented only. Single-use. No software or electronic components.

Indications for Use

Indicated for patients with inflammatory or non-inflammatory degenerative joint disease (e.g., rheumatoid arthritis, osteoarthritis, avascular necrosis), correctable valgus-varus deformity, moderate flexion contracture, or failed previous knee surgery/arthroplasty requiring revision. Requires intact medial and lateral collateral ligaments; posterior cruciate ligament must be absent, deficient, or removed. Intended for cemented use only.

Regulatory Classification

Identification

A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee 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 includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).

Predicate Devices

• Natural-Knee II System (Sulzer Orthopedics)
• Maxim Constrained Knee (Biomet)
• Coordinate Revision Knee (DePuy)

Reference Devices

• Natural-Knee II All-Poly Patella I
• Natural-Knee II Metal-Backed Patella
• Natural-Knee II Revision Stems
• Natural-Knee II Tibial Spacers I
• Natural-Knee II Revision Tibial Stems

Submission Summary (Full Text)

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K97 3412

DEC - 8 1997

## 510(k) SUMMARY

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-Knee™ II Constrained Knee System.

| Submitter: | Sulzer Orthopedics Inc.<br>9900 Spectrum Drive<br>Austin, Texas 78717<br>[phone] |
|-------------------------|--------------------------------------------------------------------------------------------------------------|
| Date: | July 18, 1997 |
| Contact Person: | Jacquelyn Hughes<br>Manager, Regulatory Affairs |
| Classification Name: | Prosthesis, knee, patellofemorotibial, semi-constrained,<br>cemented, polymer/ metal/polymer 21 CFR 888.3560 |
| Common/Usual Name: | Knee Prosthesis, Partially Constrained |
| Trade/Proprietary Name: | The Natural-Knee™ II Constrained Knee System |

#### PRODUCT DESCRIPTION

The Natural-Knee™ II Constrained Knee System is a non-porous total knee replacement intended for primary and revision knee surgeries. The components are intended for resurfacing of the knee joint where the posterior cruciate ligament is absent, deficient, or has been removed at the time of surgery. The system is a semiconstrained design and both medial and lateral collateral ligaments must be intact.

The Natural-Knee II Constrained Knee femoral component is manufactured from cobalt chromium/molybdenum (CoCr) alloy and is anatomic and asymmetrical in design. The Natural-Knee II Revision Stems may be used with the Natural-Knee II Constrained Knee System femoral component. Femoral spacers manufactured from CoCr alloy are also available for use with the Natural-Knee II Constrained Knee femoral component. A revision adapter spacer, also manufactured from CoCr, converts the internal box geometry of the Natural-Knee II Constrained Knee femoral component to match that of the Natural-Knee II Revision femoral component. The Natural-Knee II Revision Femoral Spacers may be added to the revision adapter spacer if additional augmentation is necessary.

The Natural-Knee II Constrained Knee tibial components include a baseplate and polyethylene insert. The tibial components are also anatomic and asymmetrical in design. The tibial baseplate is manufactured from Titanium alloy (Ti-4A1-6V). The baseplate is designed to be used with the Natural-Knee II Revision Tibial Spacers. The Natural-Knee II Constrained Knee tibial baseplate may be used with the Natural-Knee II Revision Tibial The tibial inserts are manufactured from Ultra High Molecular Weight Stems. Polyethylene (UHMWPe). A CoCr pin passing vertically from the posterior stabilizing eminence of the tibial insert to the tibial baseplate provides additional stability.

The Natural-Knee II Constrained Knee System is to be used with the Natural-Knee II metalbacked and all-poly patellar components.

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

- Natural-Knee II All-Poly Patella I
- Natural-Knee II Metal-Backed Patella
- Natural-Knee II Revision Stems
- Natural-Knee II Tibial Spacers I
- Natural-Knee II Revision Tibial Stems

The Natural-Knee II Constrained Knee Tibial Baseplate may also be used with existing Natural-Knee II tibial inserts. The existing Natural-Knee II tibial inserts are not compatible with the Natural-Knee II Constrained Knee Femoral Component.

### SPECIFIC DIAGNOSTIC INDICATIONS

The Natural-Knee II Constrained Knee System is intended use in the following diagnostic indications :

- 1) Patient conditions, including but not limited to, inflammatory degenerative joint disease (e.g., rheumatoid arthritis) and noninflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis).
- 2) Correctable valgus-varus deformity and moderate flexion contracture.
- 3) Those patients with failed previous surgery where pain, deformity, or dysfunction persist.
- 4) Revision of previously failed knee arthroplasty.

The Natural-Knee II Constrained Knee System is intended only for use with bone cement in the United States. Uncemented use of the Natural-Knee II Constrained Knee System is considered to be investigational in the United States. This device is intended for single use only.

#### SUBSTANTIAL EQUIVALENCE

The Natural-Knee II Constrained Knee System is substantially equivalent to the Natural-Knee II System (Sulzer Orthopedics), the Maxim Constrained Knee (Biomet), and the Coordinate Revision Knee (DePuy).

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Image /page/2/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized image of an eagle with three human profiles incorporated into its body.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

## DEC - 8 1997

Ms. Jacquelyn Hughes Manager, Regulatory Affairs Sulzer Orthopedics, Inc. 9900 Spectrum Drive Austin, Texas 78717

Re : K973412 The Natural-Knee II Constrained Knee System Requlatory Class: II Product Code: JWH Dated: September 8, 1997 September 9, 1997 Received:

Dear Ms. Hughes:

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, Drug, and Cosmetic Act (Act). This decision is based on this device being equivalent only to similar devices labeled and intended to be fixed within bone with acrylic "bone cement." You may, therefore, market your device subject to the general controls provisions of the Act and the following limitations:

- The thinnest tibial insert available is the nominal "9mm" 1. sized insert, which has a minimum polyethylene thickness under the condyles of 6.00mm.
- This device may not be labeled or promoted for non-2. cemented use.
- 3 . All labeling for this device, including package label and labeling included within the package, must prominently state that the device is intended for cemented use only.

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Page 2 - Ms. Jacquelyn Hughes

- Any non-cemented fixation of this device is considered 4. investigational and may only be investigated as a significant risk device in accordance with the investigational device exemption (IDE) regulation under 21 CFR, Part 812. All users of the device for noncemented fixation must receive approval from their respective institutional review boards (IRBs) and the Food and Druq Administration (FDA) to conduct the investigation.
The general controls provisions of the Act include requirements for annual reqistration, listing of devices, good manufacturing practices, labeling, and prohibitions against misbranding and adulteration.

If vour device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Requlations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, 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. Failure to comply with the GMP requlation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Reqister. 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 Requlations.

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 regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at [phone]. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at [phone]. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be

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Page 3 - Ms. Jacquelyn Hughes

obtained from the Division of Small Manufacturers Assistance obtained from the Division of Small Mark [phone] or at
at its toll-free number [phone] or addon'demain html" at its toll-free number [phone] Of (600) 600 - 1000
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 Radiological Health

Enclosure

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510(k) Number (if known):_____________________________________________________________________________________________________________________________________________________

Device Name: Natural-Knee™ II Constrained Knee System

# Indications For Use:

The Natural-Knee™ II Constrained Knee System is intended use in the following diagnostic indications:

- Patient conditions, including but not limited to, inflammatory degenerative joint 1. disease (e.g., rheumatoid arthritis) and noninflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis).
- 2. Correctable valgus-varus deformity and moderate flexion contracture.
- Those patients with failed previous surgery where pain, deformity, or 3. dysfunction persist.
- 4. Revision of previously failed knee arthroplasty.

The Natural-Knee™ II Constrained Knee System is intended only for use with bone cement. Uncemented use of the Natural-Knee™ II Constrained Knee System is considered to be investigational in the United States.

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Concurrence of CDRH, Office of Device Evaluation (ODE)

t

(Division Sign-Off) Division of General Restorative Devices

510(k) Number.

OR

Prescription Use

**Over-The-Counter Use**

(Optional Format 1-2-96)