CONSENSUS POSTERIOR STABILIZED KNEE

K954818 · U.S. Medical Products, Inc. · JWH · May 22, 1996 · Orthopedic

Device Facts

• Record ID: K954818
• Device Name: CONSENSUS POSTERIOR STABILIZED KNEE
• Applicant: U.S. Medical Products, Inc.
• Product Code: JWH · Orthopedic
• Decision Date: May 22, 1996
• Decision: SN
• Submission Type: Traditional
• Regulation: 21 CFR 888.3560
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

The Consensus® Posterior Stabilized Knee is indicated for use in: 1. Primary intervention of rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, or degenerative arthritis in the absence of the posterior cruciate ligament. 2. Failed osteotomy or unicompartmental replacements 3. Replacement of unsatisfactory cemented or press-fit knee components when sufficient bone stock exists.

Device Story

Consensus® Posterior Stabilized (PS) Knee System is a semi-constrained, cemented knee prosthesis; replaces knee joint surfaces in patients with absent posterior cruciate ligament. System comprises UHMWPE tibial insert (ASTM F648) and CoCrMo alloy femoral component (ASTM F75). Femoral component features stabilizing bar between posterior condyles; engages spine on tibial insert at ~65° flexion to provide stability. Used by orthopedic surgeons in clinical/hospital settings for total knee arthroplasty. Device provides mechanical articulation and stability; restores joint function; reduces pain. System components are modular; compatible with Consensus® Primary Knee patellar and tibial baseplate components. Provided sterile.

Clinical Evidence

No clinical data. Substantial equivalence established via non-clinical performance data and design comparison.

Technological Characteristics

Materials: UHMWPE (ASTM F648) for tibial insert, CoCrMo alloy (ASTM F75) for femoral component. Design: Semi-constrained, posterior-stabilized, cruciate-sacrificing. Features: Dovetail grooves for baseplate interlocking, stabilizing bar on femoral component, spine on tibial insert. Sizes: 3 tibial insert sizes (5 thicknesses), 6 femoral component sizes. Sterilization: Provided sterile.

Indications for Use

Indicated for patients requiring primary knee intervention due to rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, or degenerative arthritis with absent posterior cruciate ligament; patients with failed osteotomy or unicompartmental replacements; or patients requiring revision of unsatisfactory cemented/press-fit knee components with sufficient bone stock.

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

• Johnson&Johnson PFC® Modular Knee System (K884796)

Submission Summary (Full Text)

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K 954818
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MAY 22 1995

ATTACHMENT 8

Summary of Safety and Effectiveness

510(k) SUMMARY

US MEDICAL PRODUCTS, INC.
CONSENSUS® Posterior Stabilized Knee System

US Medical Products, Inc.
12201 Technology Boulevard
Suite 100
Austin, Texas 78727

William N. Thompson, Director
Quality Assurance and Regulatory Affairs
Voice [phone]
Fax [phone]
Date of Preparation: 15 Oct. 1995

Trade Name: Consensus® Posterior Stabilized Knee prosthesis

Common Name: Posterior cruciate ligament sacrificing knee prosthesis; PS Knee

Classification Name: Prosthesis, knee, patello/femorotibial, semi-constrained, cemented, polymer/metal/polymer, under classification 21CFR888.3560.

Substantial Equivalence: equivalent Posterior Stabilized Knee components:

Johnson&Johnson PFC® Modular Knee System, K884796, SE 03-29-89.

Device Description: The Consensus® PS Knee tibial insert component is manufactured from ultra-high molecular weight polyethylene (UHMWPE, ASTM F648), and is designed to articulate with the Consensus® PS femoral component. The insert has a spine on the central eminence which engages the crossbar of the PS femoral component. The spine is positioned so that the crossbar of the PS femoral component engages at approximately 65° flexion. The inferior surface of each component employs dovetail grooves for positive interlocking with the Consensus® Primary Knee tibial baseplate. The design is available in three sizes and each size is available in five thicknesses.

The Consensus® PS Femoral component is made of CoCrMo alloy (ASTM F75). Both the outer articulating surface and the inner box geometry of the Consensus® PS femoral component are identical to the respective surfaces of the Consensus® Primary Knee femoral component. Therefore, the PS femoral component contains the same deepened

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patella groove as the Consensus® Primary Knee femoral component for increased range of motion, utilizes the same instrumentation as the Consensus® Knee for preparing the distal femur, and employs smooth distal pegs for added Medial/Lateral stability. The Consensus® PS femoral component has a shortened patella groove to accommodate the spine of the Consensus® PS tibial insert. It also contains a stabilizing bar located between the posterior condyles which engages the spine of the Consensus® PS tibial insert at high flexion angles.

The Consensus® Posterior Stabilized Knee System will be provided sterile.

The Consensus® Posterior Stabilized Knee is designed for use with the following Consensus® Total Knee System components:

- Consensus® All Poly or metal back Patellar component
- Consensus® Porous Titanium Stemmed Tibial Baseplate
- Consensus® Nonporous Titanium Stemmed Tibial Baseplate
- Consensus® CoCr Stemmed Tibial Baseplate

**Intended Use:** The Consensus® Posterior Stabilized Knee is indicated for use in:

1. Primary intervention of rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, or degenerative arthritis in the absence of the posterior cruciate ligament.
2. Failed osteotomy or unicompartmental replacements
3. Replacement of unsatisfactory cemented or press-fit knee components when sufficient bone stock exists.

**Summary of Technological Characteristics:** The Consensus® PS Tibial Insert is an asymmetric UHMWPE cruciate-sacrificing tibial component designed to articulate with the Consensus® PS Femoral component, and the Consensus® Primary Knee patellar components. The inferior surface of the tibial component employs dovetail grooves for positive interlocking with the tibial baseplate. The design is available in three sizes and each size is available in five thicknesses. The PS Femoral component is asymmetric, with a shortened patella groove to accommodate the spine of the PS tibial insert, and contains a stabilizing bar located between the posterior condyles which engages the spine of the PS tibial insert. It is available in six sizes.

**Performance Data:** The device performs with substantial equivalence to predicate devices.

**Clinical Data:** None Required

**Conclusions from Non-clinical and Clinical Data:** The Consensus® PS Knee is substantially equivalent to the predicate device.

**Other Necessary Information:** None Required