NATURAL-HIP SYSTEM COCR REVISION STEM

K970166 · Intermedics Orthopedics · LZO · Apr 8, 1997 · Orthopedic

Device Facts

• Record ID: K970166
• Device Name: NATURAL-HIP SYSTEM COCR REVISION STEM
• Applicant: Intermedics Orthopedics
• Product Code: LZO · Orthopedic
• Decision Date: Apr 8, 1997
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 888.3353
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

The Natural-Hip System CoCr Revision Stem is intended to replace the anatomy of the femur in cases of total hip or hemi-hip replacement. The Natural-Hip System CoCr Revision Stem is intended for cemented application only and is intended for single use only. The Natural-Hip System CoCr Revision Stem is intended for use in treatment of the following: 1. Patient conditions of non-inflammatory degenerative joint disease (NIDJD), e.g., avascular necrosis, osteoarthritis and inflammatory joint disease (IJD), e.g., rheumatoid arthritis. 2. Those patients with failed previous surgery where pain, deformity or dysfunction persists. 3. Revision of previously failed arthroplasty.

Device Story

The Natural-Hip System CoCr Revision Stem is a femoral component for total or hemi-hip arthroplasty. Fabricated from cobalt chromium alloy, the stem features a bowed distal portion to match femoral anatomy and a threaded 12/14 neck trunnion for modular head attachment. The proximal surface includes normalization steps and grit-blasting to enhance PMMA cement fixation, supplemented by PMMA centralizers for mantle uniformity. Intended for cemented use, the device is implanted by orthopedic surgeons in a clinical setting to replace femoral anatomy, alleviate pain, and restore function in patients with degenerative or inflammatory joint disease or failed prior surgeries.

Clinical Evidence

Bench testing only.

Technological Characteristics

Material: Forged or wrought cobalt chromium alloy (ASTM F-799 or F-1537). Design: Cemented femoral stem, collared or collarless, grit-blasted proximal surface with normalization steps, bowed distal geometry. Modularity: Threaded Sulzer 12/14 neck trunnion. Fixation: PMMA cement centralizers.

Indications for Use

Indicated for patients requiring total or hemi-hip replacement due to non-inflammatory degenerative joint disease (e.g., avascular necrosis, osteoarthritis), inflammatory joint disease (e.g., rheumatoid arthritis), failed previous surgery, or revision of failed arthroplasty.

Regulatory Classification

Identification

A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.

Predicate Devices

• Omnifit® Long Stem (unknown 510(k))
• Ultima® Long Stem (K952859)
• PCA® Long Stem (unknown 510(k))
• Matrix Cementra® Revision Femoral Stem (unknown 510(k))

Reference Devices

• IOI metallic femoral bearing heads (K905781, K913060)
• IOI Biolox Bearing Heads (K923734, K942330)
• Zirconia Bearing Heads (K944209)
• IOI bipolar components (K833404, K873815)
• IOI unipolar components (K833403, K934159)
• IOI acetabular components (K850793, K920955, K933203, K942406, K941617, K955033, K955739)

Submission Summary (Full Text)

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510(k) SUMMARY OF SAFETY AND EFFECTIVENESS
K970166

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 CoCr Revision Stem.

**Submitter:** Intermedics Orthopedics, Inc.
9900 Spectrum Drive
Austin, Texas 78717
[phone]
APR - 8 1997

**Date:** January 15, 1997

**Contact Person:** Jacquelyn Hughes
Manager, Regulatory Affairs

**Classification Name:** Hip joint metal/ceramic/polymer semi-constrained cemented or non-porous uncemented prosthesis, 21 CFR 888.3353.

**Common/Usual Name:** Total Hip Prosthesis - Femoral Component

**Trade/Proprietary Name:** Natural-Hip™ System CoCr Revision Stem

**Device Description:**
The Natural-Hip System CoCr Revision Stem is fabricated from either forged or wrought cobalt chromium alloy which conforms to the American Standards for Testing and Materials (ASTM) standards F-799 or F-1537, respectively.

The Natural-Hip System CoCr Revision Stem features a threaded Sulzer 12/14 configured neck trunnion for attachment to IOI's currently marketed femoral heads, including Biolox and Zirconia heads, employing a Sulzer 12/14 configured bore.

The Natural-Hip System CoCr Revision Stem is available in both a collared and collarless design. The proximal one-third of the stem's surface employs normalization steps and is roughened via the process of grit blasting. The normalization steps and grit blasted surface enhance cement compression and bonding for optimal fixation of the hip stem in the femoral canal. The proximal surface of the Natural-Hip System CoCr Revision Stem also employs polymethylmethacrylate (PMMA) cement centralizers to provide even cement mantle when the stem is implanted in the femur.

The distal portion of the Natural-Hip System CoCr Revision Stem is bowed to mimic the anatomy of the femur. The Natural-Hip System CoCr Revision Stem employs a hole in the distal portion

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of the stem to allow the use of a PMMA centralizer for correct distal alignment.

The Natural-Hip System CoCr Revision Stem is intended to be used in conjunction with the following Intermedics Orthopedics, Inc. (IOI) devices that have been cleared for marketing by the FDA:

- IOI metallic femoral bearing heads [510(k)s K905781 and K913060],
- IOI Biolox Bearing Heads [510(k)s K923734 and K942330]
- Zirconia Bearing Heads [510(k) K944209],
- IOI bipolar components [510(k)s K833404 and K873815],
- IOI unipolar components [510(k)s K833403 and K934159],
- IOI acetabular components [510(k)s K850793, K920955, K933203, K942406, K941617, K955033 and K955739].

## Diagnostic Indications

The Natural-Hip System CoCr Revision Stem is intended to replace the anatomy of the femur in cases of total hip or hemi-hip replacement. The Natural-Hip System CoCr Revision Stem is intended for cemented application only and is intended for single use only. The Natural-Hip System CoCr Revision Stem is intended for use in treatment of the following:

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

## Predicate Devices:

The features employed by Natural-Hip System CoCr Revision Stem are substantially equivalent to the features employed by the following predicate legally marketed devices:

- Omnifit® Long Stem: Osteonics Corporation [510(k) number unknown to IOI].
- Ultima® Long Stem: Johnson & Johnson Professional Inc. [510(k) K952859].
- PCA® Long Stem: Howmedica Inc. [510(k) number unknown to IOI].
- Matrix Cementra® Revision Femoral Stem: Smith & Nephew Richards [510(k) Number unknown to IOI].

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