KONSTRUCT PATELLAR COMPONENT

K960856 · Biomet, Inc. · JWH · Nov 27, 1996 · Orthopedic

Device Facts

• Record ID: K960856
• Device Name: KONSTRUCT PATELLAR COMPONENT
• Applicant: Biomet, Inc.
• Product Code: JWH · Orthopedic
• Decision Date: Nov 27, 1996
• Decision: SN
• Submission Type: Traditional
• Regulation: 21 CFR 888.3560
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

The Konstruct Patellar Component is indicated for patients suffering from severe knee pain and disability. Specific indications include patellar replacement in patients who require implantation due to degenerative bone disease such as rheumatoid arthritis or osteoarthritis, primary and secondary traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis, pseudo-gout or complications from a failed prosthesis. The device is for use with bone cement only and for supplemental fixation by means of suture attached. Supplemental suture attachment is used in cases where soft tissues (tendons, ligaments) have ruptured or require reattachment.

Device Story

Konstruct Patellar Component; dome-shaped UHMWPE implant for total knee arthroplasty. Designed for cemented fixation; features peripheral suture holes for supplemental soft tissue (tendon/ligament) reattachment. Used by orthopedic surgeons in clinical settings. Suture grooves allow countersinking to prevent femoral surface contact. Enables soft tissue repair without full knee revision. Benefits patients by addressing soft tissue complications alongside standard patellar replacement.

Clinical Evidence

Bench testing only. No clinical data provided.

Technological Characteristics

Material: Ultra-High-Molecular Weight Polyethylene (UHMWPE). Design: Dome-shaped, uniform 9 mm thickness. Fixation: Bone cement with optional supplemental suture fixation via peripheral holes. Sterilization: Not specified.

Indications for Use

Indicated for patients with severe knee pain and disability requiring patellar replacement due to degenerative bone disease (rheumatoid/osteoarthritis), traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis, pseudo-gout, or failed prosthesis complications. Includes cases requiring soft tissue reattachment.

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

• AGC Total Knee System Patellar Component (Biomet, Inc.)
• Total Condylar Knee Prosthesis (Howmedica, Inc.)

Reference Devices

• TC-IV Total Knee System
• Performance Total Knee System

Submission Summary (Full Text)

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NOV 27 1996
K960856

# SUMMARY OF SAFETY AND EFFECTIVENESS

Sponsor: Biomet, Inc.
Airport Industrial Park
P.O. Box 587
Warsaw, IN 46581-0587

Device: Konstruct Patellar Component

Classification Name: Prosthesis, knee, patellofemorotibial, semi-constrained, cemented, polymer/metal/polymer (888.3560)

Intended Use: The Konstruct Patellar Component is indicated for patients suffering from severe knee pain and disability. Specific indications include patellar replacement in patients who require implantation due to degenerative bone disease such as rheumatoid arthritis or osteoarthritis, primary and secondary traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis, pseudo-gout or complications from a failed prosthesis.

The device is for use with bone cement only and for supplemental fixation by means of suture attached. Supplemental suture attachment is used in cases where soft tissues (tendons, ligaments) have ruptured or require reattachment.

## Device Description:

This component is made of Ultra-High-Molecular Weight Polyethylene (UHMWPE), a material commonly used for this type of implant. The Konstruct patella is designed for cemented use. The dome shaped topography is a standard design and is compatible with the TC-IV and Performance Total Knee Systems which received marketing clearance in 1986 and 1988, respectively.

The implants are of a uniform 9 mm thickness and have suture holes that allow for fixation supplemental to the standard acrylic fixation if necessary. The partially drilled suture holes surround the component's periphery and grooves in the articular surface allow the sutures to be countersunk so as not to contact the femoral surface. The addition of partially drilled suture holes does not effect the functioning of this device in total knee arthroplasty. What it does do is provide a mechanism for reattachment of soft tissue such as tendons or ligaments using standard suturing techniques. The Konstruct Patellar Component allows for treatment of these soft tissue complications without necessity of revising the entire knee replacement.

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Potential Risks: The potential risks associated with this device are the same as with any joint replacement device. These include, but are not limited to:

| Reaction to the bone cement | Blood vessel damage | Bone fracture |
| --- | --- | --- |
| Deformity of the joint | Soft tissue imbalance | Infection |
| Cardiovascular disorders | Delayed wound healing | Hematoma |
| Fracture of the cement | Metal sensitivity | Dislocation |
| Implant loosening/migration | Fracture of the components | Excessive wear |
| Tissue growth failure | Nerve damage | |

Substantial Equivalence: In function and overall design, the Konstruct Patellar Component is equivalent to other knee components on the market. These include:

- AGC Total Knee System Patellar Component (Biomet, Inc., Warsaw, IN)
- Total Condylar Knee Prosthesis (Howmedica, Inc., Rutherford, NJ)