---
kind: "section"
citation: "21 C.F.R. § 888.3610"
title: "21"
number: "888.3610"
heading: "Medial knee implanted shock absorber."
url: "https://uscodex.org/cfr/21/888.3610"
---

# §888.3610. Medial knee implanted shock absorber.

- (a) **Identification.** A medial knee implanted shock absorber is a device implanted outside of the knee capsule extending from the distal femur to the proximal tibia. It is intended to reduce loads on the intra-articular medial joint surface to improve symptoms of osteoarthritis. The device employs a shock absorbing mechanical system and is biomechanically stabilized by plates and screws. The device is not intended to span the lateral knee.
- (b) **Classification.** Class II (special controls). The special controls for this device are:
  - (1) Clinical data must demonstrate that the device performs as intended under anticipated conditions of use and include the following:
    - (i) Evaluation of improvement of knee function and reduction of osteoarthritis symptoms, including pain and function; and
    - (ii) **Evaluation of relevant adverse events.**
  - (2) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use and include the following:
    - (i) Evaluation of the mechanical function and durability of the implant (including evaluation of absorber unloading capacity, fretting and corrosion, static strength, wear analysis, and fatigue testing); and
    - (ii) **Evaluation of worst-case device range of motion.**
  - (3) The patient-contacting components of the device must be demonstrated to be biocompatible.
  - (4) Performance data must support the sterility and pyrogenicity of the device components intended to be sterile.
  - (5) Performance data must validate the reprocessing instructions for the reusable components of the device.
  - (6) Performance data must support the shelf-life of the device by demonstrating continued sterility, package integrity, and device functionality over the identified shelf-life.
  - (7) A training program must be included so that upon completion of the training program, the user can safely and successfully implant the device.
  - (8) Labeling must include the following:
    - (i) Validated methods and instructions for reprocessing of any reusable components; and
    - (ii) **A shelf life.**

## Notes

### Amendments

[91 FR 39009, June 29, 2026]

### Authority

Authority: 21 U.S.C. 351, 360, 360c, 360e, 360j, 360 l , 371.

### Source

Source: 52 FR 33702, Sept. 4, 1987, unless otherwise noted.

### Amendments

[91 FR 39009, June 29, 2026]