Implantable Medical Devices: 3 Common Misconceptions

Endosseous Implant - Class I Device

A medical implant is a special kind of device that is placed inside, or on the surface of the body. These devices can be permanently implanted or removed once they are no longer required.

For example, chemotherapy administration ports are non-permanent implants, as are screws used in orthopedics to repair bones (they are removed once the process of fusing the bone tissue has finished).

There are some common misconceptions about these types of devices, which we discuss in this blog:

1. Not all implantable devices are Class III

The FDA uses three regulatory classes based on the risk of the device and the level of control required to ensure its safety and effectiveness.

In this classification, class I devices are those that present a minimal risk of harm to the user, while class III devices are those that present the highest level of risk.

It is generally believed that all implantable devices are class III, however, the majority are class II and a few are class I:


Number of Implantable Devices by Classification (






Class I




Class II




Class III








For example, Endosseous Dental Implants are class I.

An example of class II implants are the devices for hip replacement.

Heart valve replacements are examples of Class III devices.


2. Not all implantable devices require PMA

Another common misconception is that a PMA is required for all implantable devices.

However, only class III devices (those that present a high risk of injury or illness) require FDA approval prior to market entry or PMA (Pre-Market Approval).

As previously discussed, most of the implantable devices are Class II, so they don’t require a PMA but a notification prior to entering the market, 510 (K) (Pre-Market Notification).


3. Not all implantable devices require a tracking system (Medical Device Tracking 21 CFR Part 821)

The purpose of the tracking requirement is for the manufacturer to recall from the market, the defective devices that may cause harm to patients as quickly as possible.

The manufacturers of the devices, for which the FDA has established this requirement, must implement a procedure to trace the device to the patient, through the entire distribution chain. This requirement applies throughout the life of the device.

This section of the regulation is not exclusive to the implantable device, but could apply to any class II or class III device that falls into one of the following categories:

  • Devices whose failure could have serious adverse consequences for the patient's health
  • Devices that are going to be implanted for more than one year
  • Devices that are used to sustain the patient's life out of the hospital environment

Based on these criteria, the FDA maintains a list of devices that require compliance with part 821 on its website.

At the moment, only 48 types of devices are on that list. The FDA continuously updates this list by adding devices and/or eliminating the requirement of devices that are currently on it.



Author: Vanessa Rivel

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