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The RHEO KNEE is a microprocessor-controlled knee with an optimal combination of stability and safety. It enables exceptionally natural and effortless gait – even on difficult terrain. The RHEO KNEE is easy to fit, and delivers reliable user outcomes.

Key Features

  • Auto adaptive real-time stance and swing control.
  • Dependable and easy swing initiation on all surfaces.
  • Automatic stumble recovery.
  • Manual extension lock.
  • Weatherproof design allows exposure to fresh water splashes.
  • Accompanying Össur Logic app for iOS devices provides:
    • Simple practitioner setup and adjustment, and printable user activity reports.
    • Functional training exercises for improved user confidence.
    • Selection of user preferences and monitoring of step count and battery charge level.
  • Smart Extension makes raising from a squatted position easier with less resistance.
  • Facilitates stepping over obstacles and stepping backwards.

Impact Levels

Impact LevelExample


Daily activities involving gentle, steady walking with the use of a walking aid.

Example: Moving around at home, modest walking in the community.


Daily activities involving average walking with the ability to vary speed or walking pattern.

Example: Going to the shops, confident outdoor walking.

More Dynamic Solutions


RHEO KNEE and RHEO KNEE XC come with ÖSSUR LOGIC software, which enables professionals to adjust easily the functionality for each user and access valuable activity reports.

In addition to checking knee status and battery charge level, the new, enhanced user mode offers access to a specially designed training program. The Össur Logic Training feature enables Clinicians to empower users with easy exercises to practice at home and at their own pace, improving confidence and gait. Exercise include symmetric weight bearing, rolling over the toe, more symmetric sitting down and stair descent.

Software is available for iOS devices (iOS 9.3 or later), and communicates wirelessly via Bluetooth.

Expert Mode*

  • Knee setup: facilitates automatic and manual adjustments, monitors knee angle and load.
  • Enhanced Stability Control options: provides transitional settings for first steps.
  • Activity reports: records step count, walking speed distribution, average walking speed (PDF format available).

*License code is required for expert mode.

User Mode

  • Training: functional training exercise program
  • Monitor remaining battery charge and step count
  • Instructions-for-use
  • Adjust sounds and vibration
  • Turn extension hold on/off

Össur Logic App on the App Store

The Össur Logic App is available free of charge on the App Store.

Expert mode is only available for the healthcare professional with training from Össur.

NOTE: Össur Logic cannot be used with older versions of RHEO KNEE as those models do not include the Bluetooth Low Energy hardware required to communicate with iOS devices.

RHEO KNEE Specifications

RHEO KNEE® Product Information
Amputation Level:


Knee Disarticulation

Impact Level: Low to Moderate
Maximum Patient Weight: 136kg
Build Height: 236mm (9 1/4")
Knee Flexion: 120º
Aluminum Frame Construction: Yes
Weight: 1.61kg (3.56lbs) (Approx.)


RKN130003 3 Years Warranty (No Service Check)
RKN130005 5 Years Warranty (Incl. Service Check at 40 Months)

RHEO KNEE Kit Includes

  • RHEO KNEE Power Supply w/Plug
  • Terms of warranty
  • Instructions for use

RHEO KNEE with Threaded Top Adapter

RHEO KNEE with threaded top adapter is the solution for knee disarticulation amputees and those with long residual limbs.

To order RHEO KNEE with threaded top adapter, order the RHEO KNEE Kit and add Össur's Female Pyramid Insert to the order.

Female Pyramid Insert
A-145310 Female Pyramid Insert / Threaded Top Adapter 9mm (3/8") 33g (1.16oz)
RHEO KNEE Accessories
N/A ÖSSUR LOGIC for iOS devices is available on the App Store
BIC00110 Bionic Protector for RHEO KNEE
PRX00421 Power Supply w/Plug
RHEO KNEE Kit Extended Warranty*
* Maximum total warranty period is 5 years, must be purchased within 12 months after original purchase date.
** If total warranty time acquired adds up to 5 years, then 40 month service check will be mandatory.
RKN3GE2YR Additional 2 Year Warranty
RKN3SC20M Voluntary 20 Month Service Check
RKN3SC40M Mandatory 40 Month Service Check**
RKNSCAW Voluntary After Warranty Service Check
Unity Kits
Part#DescriptionApplicable Foot Kits
UTF0001 Unity TF Valve Kit All

Support Documents

RHEO KNEE Catalog page
RHEO KNEE Information Sheet
RHEO KNEE Instructions for use
RHEO KNEE Terms of warranty

   Identify weatherproof models by this icon. Do not submerse, or expose to chlorinated or salt water. Older models of RHEO KNEE may not be weatherproof.

Previous versions*

* HF37xxxxx RHEO KNEE Weatherproof series
RHEO KNEE® 3 Instructions For Use
RHEO KNEE® 3 Terms of Warranty Document

Previous versions**

**HF341xxx RHEO KNEE 3 without lock series, and HF35xxxx RHEO KNEE 3 with lock series
RHEO KNEE® 3 Instructions For Use
RHEO KNEE® 3 Quick Reference Card
RHEO KNEE® 3 Technical Manual
RHEO KNEE® 3 Terms of Warranty Document