COBALT-CHROMIUM-MOLYBDENUM (CO-CR-MO) ALLOY FEMORAL HEADS W/CO-NIDIUM SURFACE TREATMENT

K960278 · Zimmer, Inc. · JDI · Jul 25, 1996 · Orthopedic

Device Facts

• Record ID: K960278
• Device Name: COBALT-CHROMIUM-MOLYBDENUM (CO-CR-MO) ALLOY FEMORAL HEADS W/CO-NIDIUM SURFACE TREATMENT
• Applicant: Zimmer, Inc.
• Product Code: JDI · Orthopedic
• Decision Date: Jul 25, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 888.3350
• Device Class: Class 2
• Attributes: Therapeutic

Indications for Use

Femoral heads are single-use devices that are mated via a press-fit tapered neck with titanium or cobalt-chrome alloy femoral stems in total and hemi-hip arthroplasty procedures.

Device Story

Cobalt-Chromium-Molybdenum alloy femoral heads; spherical head portion; highly polished; Co-Nidium surface hardening process; diameters 22-32 mm (total hip) and 38-63 mm (hemi-hip); tapered interface for modular femoral stem attachment. Used in orthopedic surgery; implanted by surgeons. Surface treatment enhances abrasive wear resistance and fatigue strength without altering corrosion resistance or dimensional specifications. Benefits include improved durability and wear characteristics compared to non-hardened counterparts.

Clinical Evidence

Bench testing only. Wear testing showed improved abrasive wear resistance; corrosion testing confirmed breakdown potential unchanged; fatigue testing showed higher fatigue strength; dimensional analysis and coefficient of friction showed no change; microhardness and ESCA data confirmed increased hardness and hardening depth.

Technological Characteristics

Material: Cobalt-Chromium-Molybdenum alloy. Surface treatment: Co-Nidium (nitriding) process. Form factor: Spherical head with tapered neck interface. Diameters: 22-63 mm. Sterilization: Not specified.

Indications for Use

Indicated for patients undergoing total or hemi-hip arthroplasty procedures requiring a femoral head component.

Regulatory Classification

Identification

A hip joint metal/polymer semi-constrained cemented 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 includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).

Predicate Devices

• Harris/Galante Porous Total Hip
• Enhanced Modular Austin Moore Hip Prosthesis
• HG MultiLock™ Hip Prosthesis With Ti-Nidium® Surface Hardening Process
• MG II® Total Knee System with Ti-Nidium Surface Hardening Process

Submission Summary (Full Text)

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JUL 25 1996
P.O. Box 708
Warsaw, IN 46581-0708
219 267-6131

# K960278

## Summary of Safety and Effectiveness
Cobalt-Chromium-Molybdenum Alloy Femoral Heads
with *Co-Nidium™* Surface Hardening Process

- Submitted by:
Zimmer, Inc.
P.O. Box 708
Warsaw, IN 46581-0708

- Prepared by:
Lynnette Whitaker, RAC
Manager
Regulatory Affairs

- Date:
January 17, 1996

- Trade Name:
Cobalt-Chromium-Molybdenum (Co-Cr-Mo) Alloy Femoral Heads with *Co-Nidium* Surface Hardening Process

- Classification Name:
Hip Joint Metal/Polymer Semicconstrained Cemented Prosthesis

- Predicate Devices:
- Harris/Galante Porous Total Hip
- Enhanced Modular Austin Moore Hip Prosthesis
- HG MultiLock™ Hip Prosthesis With *Ti-Nidium®* Surface Hardening Process
- MG II® Total Knee System with *Ti-Nidium* Surface Hardening Process

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A Bristol-Myers Squibb Company

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- Device Description

The design of the femoral heads includes a spherical head portion that is highly polished and processed with the Co-Nidium surface treatment. Femoral heads for total hip arthroplasty procedures are available in diameters from 22 to 32 mm with varying neck lengths. Femoral heads for hemi-hip arthroplasty procedures are available in 38 to 63 mm outer diameters. The femoral heads include a tapered portion that fits securely onto a modular femoral stem component.

- Intended Use

Femoral heads are single-use devices that are mated via a press-fit tapered neck with titanium or cobalt-chrome alloy femoral stems in total and hemi-hip arthroplasty procedures.

- Performance Data

Wear testing demonstrated improved abrasive wear resistance when compared to the predicate device. Corrosion testing demonstrated that the breakdown potential of the alloy material is not changed by surface hardening. Fatigue testing indicated that the fatigue strength of the nitrided alloy is higher than the fatigue strength of currently marketed devices. Dimensional analysis and coefficient of friction data showed no change for the nitrided femoral heads. Microhardness and ESCA data exhibited higher hardness and depth of hardening when compared to the predicate device.

RA01651K.RP

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