MLI SOFT TISSUE SCREW & WASHER SYSTEM

K962194 · Medicinelodge, Inc. · MBI · Jul 30, 1996 · Orthopedic

Device Facts

• Record ID: K962194
• Device Name: MLI SOFT TISSUE SCREW & WASHER SYSTEM
• Applicant: Medicinelodge, Inc.
• Product Code: MBI · Orthopedic
• Decision Date: Jul 30, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 888.3040
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

MedicineLodge, Inc. soft tissue anchoring bone screws and washers are indicated for use in soft tissue graft fixations to the femur or tibia, or both, during cruciate ligament, tendon or other soft tissue graft (e.g. semitendinosus) repair procedures.

Device Story

System consists of orthopedic bone screws and washers used for soft tissue graft fixation to bone; screws are self-tapping, manually inserted using 3.5mm hex driver; washers feature distal spikes to anchor graft; used by surgeons in orthopedic procedures; device provides mechanical fixation of graft to femur or tibia; benefits include secure graft attachment during ligament/tendon repair.

Clinical Evidence

Bench testing only. Static tensile testing performed on four screw/washer configurations using a bass wood model to simulate clinical application. Primary endpoint was yield load; results showed MLI constructs performed as well or better than predicate systems. Failure modes were consistent with established literature (Matthews et.al, Kurosaka et.al).

Technological Characteristics

Materials: Ti6Al4V ELI (ASTM F-316). Screw design: ISO 5835 compliant, self-tapping, 4.5mm cortical and 6.5mm cancellous diameters. Washer configurations: round, triangular, and oval with distal spikes. Insertion: manual 3.5mm hex driver. Sterilization: sterile and non-sterile options.

Indications for Use

Indicated for soft tissue graft fixation to femur or tibia during cruciate ligament, tendon, or other soft tissue repair procedures.

Regulatory Classification

Identification

A smooth or threaded metallic bone fixation fastener is a device intended to be implanted that consists of a stiff wire segment or rod made of alloys, such as cobalt-chromium-molybdenum and stainless steel, and that may be smooth on the outside, fully or partially threaded, straight or U-shaped; and may be either blunt pointed, sharp pointed, or have a formed, slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a guide pin for insertion of other implants, or it may be implanted through the skin so that a pulling force (traction) may be applied to the skeletal system.

Predicate Devices

• Linvatec Concept Soft Tissue Anchoring Implants
• Arthrotek Ligament Screw System
• Mitek Screws and Washers

Reference Devices

• Matthews et.al (literature)
• Kurosaka et.al (literature)

Submission Summary (Full Text)

{0}

K962194

JUL 30 1996

# Premarket Notification

510(k) Summary of Safety and Effectiveness Information

## DATE OF SUMMARY PREPARATION

June 5, 1996

## MANUFACTURER

MedicineLodge, Incorporated
152 South 600 West
Logan, Utah 84321
Telephone: [phone]
Fax: [phone]

## MANUFACTURER CONTACT PERSON

Wade Fallin
Vice President of R&D
MedicineLodge, Inc.
152 South 600 West
Logan, Utah 84321
Telephone: [phone]
Fax: [phone]

## PROPRIETARY NAME

MedicineLodge, Inc. (MLI) Soft Tissue Screw and Washer System

## COMMON NAMES

Orthopedic Bone Screw
Orthopedic Washer

## CLASSIFICATION NAME

Non-degradable Soft Tissue Fastener

## CLASSIFICATION REFERENCE

Currently, no FDA classification exists for Non-degradable Soft Tissue Fasteners

## DEVICE PRODUCT CODE

MBI

34

{1}

35

# CLASSIFICATION PANEL

Orthopedic and Rehabilitation Devices

# PROPOSED REGULATORY CLASS

In accordance with FDA classification of fixation bone screws and orthopedic washers as Class II medical devices, this device system is proposed for placement in Class II.

# REASON FOR PREMARKET NOTIFICATION

The MLI Soft Tissue Screw and Washer System is a new medical device proposed for placement in Class II.

# SPECIAL CONTROLS

At this time, Food and Drug Administration generated Performance Standards applicable to MedicineLodge, Inc. Soft Tissue Screws and Washers are not in force. However, MedicineLodge, Inc. has conducted mechanical testing on four screw/washer configurations to demonstrate the substantial equivalence of the device. Additionally, MedicineLodge, Inc. utilizes materials and vendor certifications, in-house standard operating procedures (SOP's), and ASTM standards, as appropriate.

# INDICATIONS FOR USE

MedicineLodge, Inc. soft tissue anchoring bone screws and washers are indicated for use in soft tissue graft fixations to the femur or tibia, or both, during cruciate ligament, tendon or other soft tissue graft (e.g. semitendinosus) repair procedures.

# SUBSTANTIALLY EQUIVALENT PREDICATE DEVICES

MedicineLodge, Inc. believes that several commercially available devices are substantially equivalent to the MLI Soft Tissue Screw and Washer System. Within the proposed class, the following devices are used as predicate devices for comparison:

1) Linvatec Concept Soft Tissue Anchoring Implants
Linvatec, Inc.; Largo, FL

2) Arthrotek Ligament Screw System
Arthrotek, Inc., Ontario, CA

3) Mitek Screws and Washers
Mitek Surgical Products, Inc.; Norwood, MA

MedicineLodge, Inc. believes that the information presented below demonstrates the substantial equivalence of the MLI Soft Tissue Screw and Washer System when compared to the above selected predicate devices.

{2}

36

# SUBSTANTIAL EQUIVALENCE COMPARISON

To begin, the materials, method of manufacture, method of sterilization, and device packaging for all MLI Soft Tissue Screw and Washer System components are equivalent to those used for the selected predicate devices.

MLI Soft Tissue Screws and Washers are indicated for use in soft tissue graft fixations to the femur or tibia, or both, during cruciate ligament, tendon or other soft tissue graft (e.g. semitendinosus) repair procedures. The previously listed predicate device systems are similarly indicated for procedures involving soft tissue reconstruction.

The MLI Soft Tissue Screws and Washers are designed to be used as an assembly unit. The MLI Soft Tissue Anchoring Screws are provided in standard sizes, as tabulated below:

| Screw Diameter | Screw Length |
| --- | --- |
| 4.5 mm (Cortical) | 30 mm - 60 mm, in 2 mm increments |
| 6.5 mm (Cancellous) | 20 mm - 55 mm, in 5 mm increments |

MLI Screws are equivalent in design to currently marketed standard bone screws, with all threads and defining screw features conforming to ISO 5835, Metal Bone Screws with Hexagonal Drive Connection, Spherical Under-Surface of Head, Assymmetrical Thread Dimensions. The screws are self-tapping and are designed to be manually inserted using a standard 3.5 mm hex driver. Engineering Drawings are provided in Exhibit I for reference.

The MLI Washers are designed to be universally compatible with both the 4.5 mm and 6.5 mm MLI Screws and are provided in the three following design configurations to allow the surgeon a variety of washers to choose from:

| Washer Shape | Washer Diameter |
| --- | --- |
| Round | 14 mm, 17 mm, 20 mm |
| Triangular | 17.5 mm, 20.5 mm |
| Oval | 19 mm, 22 mm |

The washers possess spikes spaced equidistant from each other on the distal side of the washer to penetrate the host bone and thus anchor the graft in place. Engineering drawings of the washers are also provided in Exhibit I for reference.

Although the washer design configurations listed above may vary slightly from standard washers used in soft tissue repair, testing performed by MedicineLodge, Inc. shows that these differences do not compromise the performance of the washers relative to standard round washers in their intended clinical use. This testing is discussed below.

## DEVICE TESTING

MedicineLodge, Inc. has conducted device testing on a variety of screw/washer configurations to assess the performance of the MLI Soft Tissue Screw and Washer

{3}

System. These results were then used to compare the performance of the MLI Screws and Washers to a commercially marketed soft tissue screw and washer system.

The following tests were conducted using the indicated screw/washer combinations:

(i) Test #1: Fixation strength of the MLI 4.5mm X 52mm Cortical Screw and MLI-Small Round Washer (13 mm) in Static Bone Patellar Tendon Tensile Testing in a Bass Wood Model.
(ii) Test #2: Fixation strength of the MLI 4.5mm X 52mm Cortical Screw and MLI-Large Round Washer (18 mm) in Static Bone Patellar Tendon Tensile Testing in a Bass Wood Model.
(iii) Test #3: Fixation strength of the MLI 4.5mm X 52mm Cortical Screw and MLI-Triangular Washer (11.5 mm) in Static Bone Patellar Tendon Tensile Testing in a Bass Wood Model.
(iv) Test #4: Fixation strength of the MLI 4.5mm X 52mm Cortical Screw and MLI-Football Washer (11.5 mm x 8.5 mm) in Static Bone Patellar Tendon Tensile Testing in a Bass Wood Model.

The mode of failure for all MLI Screw and Washer configurations was similar for all screw/washer constructs tested, wherein the ligament pulled out from under the washer. The modes of failure are also consistent with results obtained by Matthews et.al and Kurosaka et.al where the site of failure was at the point of ligament anchorage to the implant. It is important to note that yield of the graft construct results in permanent deformation of the ligament, which can in turn result in a loose or lax graft. For this reason, MedicineLodge, Inc. believes that the yield load data best measures the observed mode of failure.

When the yield load results for the various MLI Soft Tissue Screw and Washer System screw/washer constructs were compared to the currently marketed screw/washer construct, the MLI screw/washer constructs all performed as well or better than the predicate screw/washer construct.

It is important to state that the washer sizes that will comprise the MLI Soft Tissue Screw and Washer System will be larger than those tested. The thus increases the distal surface area of the washers, which in turn should result in increased fixation strength of the graft construct in true clinical application of the product. In particular, for the Football washer (tested size: 11.5mm; marketed sizes: 19mm and 22mm), this size increase should provide additional assurance that the device will perform equivalent to the predicate screw/washer construct.

It is our belief that these results confirm the equivalence of the MLI Soft Tissue Screw and Washer System relative to the tested predicate device in testing devised to simulate clinical application of the product.

## CONCLUSION

Based on the design concept, indications for use, use of standard materials, and feature comparisons to the selected predicate devices, MedicineLodge, Inc. believes that sufficient evidence exists to conclude that MLI Soft Tissue Screw and Washer System is

{4}

substantially equivalent to existing legally marketed soft tissue anchor screw and washer systems.

Table 1 on the following page summarizes the relevant feature comparisons between the MLI Soft Tissue Screw and Washer System and the selected predicate devices.

38

{5}

39

TABLE 1
Feature comparisons between the MedicineLodge, Inc. Soft Tissue Anchoring Screw and Washer System and a selected predicate device system (differences are indicated in **bold** print).

| | MLI Soft Tissue Screw and Washer System | Mitek Screws and Washers | Linvatec Concept Soft Tissue Anchoring Set | Arthrotek Ligament Screw and Washer System |
| --- | --- | --- | --- | --- |
| Indications | MedicineLodge, Inc. soft tissue screws and washers are indicated for use in soft tissue graft fixations to the femur or tibia, or both, during cruciate ligament, tendon or other soft tissue graft (e.g. semitendinosus) repair procedures. | Mitek screws and washers are used to attach ligaments, tendons and other soft tissue to bone. | Concept soft tissue screws and washers are used to attach ligaments, tendons and other soft tissue to bone. | Arthrotek Ligament Screw and Washer system is designed to produce an efficient surgical procedure for iliotibial tenodesis in anterior cruciate reconstruction. |
| Materials | Ti6Al4V ELI (per ASTM F-316) | Ti6Al4V ELI (per ASTM F-316) | Ti6Al4V ELI (per ASTM F-316) | Ti6Al4V ELI (per ASTM F-316) |
| Cortical Screws | Length: 30 mm to 60 mm, in 2 mm increments
Outer Diameter: 4.5 mm | Length: 26 mm to 76 mm, in 2 mm increments
Outer Diameter: 4.5 mm | Length: 30 mm to 45 mm, in 5 mm increments; 50 mm to 70 mm with smooth proximal shank, in 10 mm increments.
Outer Diameter: 3.5 mm | Length: 30 mm to 80 mm, in 2 mm increments
Outer Diameter: 4.5 mm |
| Cancellous Screws | Length: 20 mm to 55 mm, in 5 mm increments
Outer Diameter: 6.5 mm | Length: 20 mm to 50 mm, in 5 mm increments
Outer Diameter: 6.5 mm | Not Listed | Length: 25 mm to 55 mm, in 5 mm increments
Outer Diameter: 6.5 mm |
| ISO Conformance of Screw Design | Yes | Yes | Yes | Yes |
| Screw Head Profile | Low profile | Low Profile | Low Profile | Low Profile |
| Surface Finish | Satin Texture | Satin Texture | Satin Texture | Satin Texture |
| Tapped/Self-tapping | Self-tapping | Self-tapping | Self-tapping | Tapped hole |
| Method of Insertion | 3.5mm Hex Driver | 2.5mm Hex Driver | 3.5mm Hex Driver | 2.5mm Hex Driver |
| Washers | Round: 14mm, 17mm, 20mm
Triangular (Delta): 17.5mm, 20.5mm
Oval (Football): 19mm, 22mm | Round: 14mm, 17mm, 20mm | Round (with post): 14mm, 17mm, 20mm
Round (Flat Washers): 14mm, 17mm | Round: 14mm, 18mm |
| Suture Holes in Washer | No | No | Yes | Yes |
| Imbrications on Distal Surface of Washer | Yes | Yes | No | No |
| Sterilization Status | Sterile & Non-sterile | Sterile & Non-sterile | Sterile & Non-sterile | Sterile & Non-sterile |
| Manufacturer | MedicineLodge, Inc. | Mitek Surgical Products, Inc. | Linvatec, Inc. | Arthrotek, Inc. |
| Currently Marketed? (Presumed 510(k) Approved) | N/A | Yes | Yes | Yes |