Reviewers Guidance Checklist For Intramedullary Rods

 This guidance was written prior to the February 27, 1997 implementation of FDA's Good Guidance Practices, GGP's. It does not create or confer rights for or on any person and does not operate to bind FDA or the public. An alternative approach may be used if such approach satisfies the requirements of the applicable statute, regulations, or both. This guidance will be updated in the next revision to include the standard elements of GGP's.

Version #4

Contents

Appendices

I. GENERAL CONTENT OF A REVIEW

1. Follow the "Third Party Review: An Instruction Manual for Conducting Reviews of Premarket Notifications" supplied to Third Parties.
2. Follow the "Device Labeling Guidance" in the ODE Blue Book.
3. Use and modify as appropriate the boilerplate review memo in the ODE New Reviewer Training Manual.

II. DESCRIPTION OF PREDICATE(S) AND DEVICE UNDER REVIEW

1. Compare the intended use of the new device to the predicate(s). Intramedullary rods are generally rod shaped devices with or without screw holes at either end for fixation to bone. These class II devices are defined in 21 CFR 888.3020 as "a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the medullary (bone marrow) canal of long bones for the fixation of fractures" (product code 87HSB). Any other intended uses should be removed from the labeling or supported by clinical data. Some designs of IM rods may be used in a variety of bones, while other designs are site specific (e.g. tibia). The site of application of the predicate device(s) should be consistent with the intended use of the new device.
2. Certain intramedullary rods may require more analysis than is covered in this document. Examples of such devices might include a rod with a lower rigidity, rods that are adjustable in length after implantation, or magnetic alignment of bone screws to attach a rod. Such devices which involve new and/or complex issues will not be reviewed by third parties because special analysis of the risks and mechanical and/or animal testing may be necessary which is beyond the scope of this document.
3. Describe the device as outlined in appendices 1, 2 and 3.

III. COMPARE THE PREDICATE(S) AND DEVICE UNDER REVIEW

1. Compare the intended uses, design, materials, properties, methods of fixation, etc. of the device under review to the same parameters of a predicate device, listing all similarities and differences between the two devices.
2. Give reasons why each difference does or does not add new or increased risks and complications, based on current engineering technology and clinical results published about intramedullary rods as well as based on what has been previously cleared by FDA. Common complications involving intramedullary rods include: loss of alignment, distraction of the fracture, infection, limb shortening, migration, muscle atrophy, non-union, protrusion through cortex, loss of range of motion, vascularity effects due to rod dimensions/geometry.
3. Identify the potential benefits of the new device compared to the predicate devices.
4. Use the above information to justify test requirements as described below.

IV. DEVICE TESTING

The reviewer is responsible for assessing the information required to determine safety and effectiveness based on the particular design parameters of the device under review. The following are examples of tests that have been required for previous devices submitted to FDA. However, new information may suggest a different approach. The reviewer should justify test requirements and conclusions based on supportive references. If testing of the device is necessary, a summary of the methods and results should be organized as suggested in appendix 4.

1. A device which has essentially the same design and materials as the predicate should not require testing unless there is new information which raises safety and effectiveness concerns.
2. Intramedullary rods are generally made out of medical grade CoCrMo, Ti-6Al-4V or 316 LVM stainless steel. Materials or combinations of materials with limited or no history of safe use as orthopedic implants should demonstrate a biological response at least as good as a predicate or substantially equivalent device when tested, e.g., according to the ISO 10993 for Medical Devices and in an appropriate animal study.
3. The static load to failure of the device is only necessary for new designs in which the rigidity significantly differs from predicate designs.
4. If the design under review has any stress risers not present in the predicate design, fatigue testing of the assembly should be performed, or a rationale for why such testing is not necessary should be presented.
5. Any reasonably known and available animal or clinical data about devices containing similar materials and designs should be summarized in a table. Additional animal or clinical data may be required if the bench testing methods or results of other tests raise concerns.

V. BIBLIOGRAPHY

Provide a bibliography if references are given (e.g., appendix 4).

lengths

longitudinal curvature

diameter

cross sectional shape (e.g., circular, fluting, open, closed, slotted, width of opening)

fixation mechanism (e.g., interference, elastic deformation of the device, bone screws)

number of fixation points

orientation of the open section and other asymmetries in the sagittal and coronal planes (e.g.: curved, bent ends, straight, s-shaped, stepped)

potential critical stress concentrators

number to be implanted

design of ends (e.g., flat, pointed, blunt, threaded, round)

insertion/extraction mechanism

For each part of each component of both the device under review and, as much as possible, the predicate device, provide the following:

The review memo should provide a summary of each mechanical bench testing report submitted in the 510k. This should include a list of the essential test parameters and results as well as the persons/labs generating the data. All reviews should be organized the same way. For example, a summary of each report should include (where applicable), but is not limited to the following:

REFERENCE

TEST IDENTIFICATION

SAMPLE DESCRIPTION (Design, Materials, Processing methods)

MEDIUM SURROUNDING THE SAMPLES BEFORE AND DURING TESTING

MECHANICAL LOADING

TEST SETUP

RESULTS

Test standards for intramedullary rods include the following:

ASTM F-383: Practice for Static Bend and Torsion Testing of Intramedullary Rods

ASTM F-1264: Standard Guide for Mechanical Performance Considerations for Intramedullary Fixation Devices

Draft ASTM Standard Definitions of Terms for Sizing of Intramedullary Fixation Devices (IMFD's) and Associated Instrumentation

Draft ASTM Standard Practice for Measuring Intramedullary Fixation Devices (IMFD's) and Reamer Dimensions

Draft ASTM Standard Practice for Low Cycle Intrinsic Bending Fatigue Testing of Intramedullary Fixation Devices (IMFD's)

Draft ASTM Standard Practice for Static Testing Under Combined Axial Compression and Bending Loads for Proximal and Distal Cortical Locking Mechanisms of Intramedullary Fixation Devices (IMFD's)

Draft ASTM Standard Practice for Low Cycle Fatigue Testing Under Combined Axial Compression and Bending Loads for Proximal and Distal Cortical Locking Mechanisms of Intramedullary Fixation Devices (IMFD's)

Draft ASTM Standard Practice for Static Intrinsic Bending, Torsion, and Radial Compliance Testing of Intramedullary Fixation Devices (IMFD's)

5 1 0 (k) R E V I E W

REASON FOR APPLICATION   New device.

1. The intended use of the above referenced device and predicate devices are essentially the same.
2. The design of the above referenced device and predicate devices are similar except for small differences that should not affect safety and effectiveness.

DESCRIPTION OF EACH COMPONENT UNDER REVIEW IN THIS 510K

ROD DESIGN FEATURES
straight
lengths: 200-300 mm
solid
diameter: 8 mm
cross sectional shape: oval
fixation methods: 2 bone screws
asymmetries:

a single rod is implanted in the canal
design of ends

COMPARABLE PREDICATE DEVICES

PREDICATE DEVICE I REVIEWED RECENTLY

REASON FOR APPLICATION   New device.

length: 155 mm
straight
diameter : 9-15 mm
solid
circular cross sectional shape
10 flutes and 3 slots run from the distal end to the screw holes.
fixation method: interference or bone screws
number of fixation points: proximally (at the humeral head) there are 4 screw holes and 4 suture holes.
a single rod is implanted in the canal
blunt distal end
flat proximal end with threaded insertion/extraction hole

OTHER PREDICATE DEVICES (see attached)

The differences in the design (compared to predicate devices) do not raise new types of safety and effectiveness questions (risks) not seen before in similar devices. The same risks occur in both devices.

TECHNOLOGICAL CHARACTERISTICS:

There are no important differences between the device submitted in this 510k and similar devices which would require testing. A 510(k) indications for use statement, truthful and accuracy statement and summary of safety and effectiveness were submitted as required in the Safe Medical Devices Act.

REVIEWED BY:________________

ATTACHMENTS:

design drawings
predicate device
intended use statement

CONTACT HISTORY: