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From rehabilitation, to the home and office, to the gym and the trail, RHEO KNEE XC confidently goes anywhere. Whether rehabilitating on a spin cycle, navigating tight spaces, strolling around town, or hiking a trail in the rain, RHEO KNEE XC provides the perfect balance of stability and dynamics.

Key Features

  • Weatherproof design allows exposure to splashing of water.
  • Magnetorheologic technology enables an instant response so that users never have to wait for the knee to catch up with them.
  • Smart gait detection, including kinematic sensor technology, ensures stability and dynamic response in every situation.
  • Advanced actuator and resistance control ensure best possible resistance, e.g. more support in stair descent and minimum effort needed in level ground gait.
  • Advanced extension assist mechanism.
  • Effortless swing initiation enables a smoother gait, even in crowds and confined spaces.
  • Allows high impact activities such as running and jogging.
  • Extension lock mechanism, to lock the knee in full extension and increase safety and comfort under specific circumstances.
  • Efficient cycling and secure stops with Automatic Cycling Recognition.
  • Allows step-over-step stair ascent.
  • ÖSSUR LOGIC app offers two levels of experience one for the user and another for the practitioner.

Impact Levels

Impact LevelExample


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

Example: Going to the shops, confident outdoor walking.


Daily activities involving fast walking, jogging and climbing stairs.

Example: Heavy-lifting, manual labor, recreational sports.

More Dynamic Solutions

More Knees and Legs

We do things differently. That’s why, while other leading microprocessor knees still employ traditional hydraulic solutions, RHEO KNEE XC features the cutting-edge, highly-responsive magnetorheologic technology popularized by the aerospace and automotive industries. And that makes all the difference.

For the most dynamic experience for users returning to their daily activities, we recommend RHEO KNEE XC with Pro-Flex® and Iceross Seal-In.

Pro-Flex combines nearly double the range of motion and energy return of a conventional carbon fiber foot with a more natural center of pressure. This is the ideal combination for people who want to enhance their mobility and return to regular activities and to a dynamic lifestyle.

For the most demanding users, we recommend RHEO KNEE XC in combination with Pro-Flex® XC

Pro-Flex XC provides exellent vertical compression, all terrain compliance and toe-off energy for active users who enjoy hiking and jogging in addition to level-ground walking. Add Unity® elevated vacuum for excellent volume control and suspension, with minimal added weight and no added build height.

RHEO KNEE XC Specifications

RHEO KNEE® XC Product Information
Amputation Level:


Knee Disarticulation

Impact Level: Moderate To High
Weight Of Knee: 1.61kg (3.56lbs)
Build Height: 236mm (9 1/4")
Knee Flexion: 120º
Aluminum Frame Construction: Yes
Max Patient Weight 136 kg (300 lbs) - (Impact Level: Moderate)
110 kg (243 lbs) - (Impact Level: High)


Part# Description
Kit Includes: RHEO KNEE XC, RHEO KNEE Power Supply w/Plug, Warranty Certificate, User Manual.
RKNXC0002 2 Years Warranty (No Service Check)
RKNXC0003 3 Years Warranty (No Service Check)
RKNXC0004 4 Years Warranty (Incl. Service Check at 40 Months)
RKNXC0005 5 Years Warranty (Incl. Service Check at 40 Months)

RHEO KNEE XC with Threaded Top Adapter

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

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

Female Pyramid Insert
Part# Description Height Weight
A-145310 Female Pyramid Insert / Threaded Top Adapter 9mm (3/8") 33g (1.16oz)
RHEO KNEE XC Accessories
Part# Description
RKNLPCWB1 RHEOLOGIC Workbench Software for PC use
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 XC Kit Extended Warranty*
Part# Description
* Maximum total warranty period is 5 years, must be purchased within 20 months after original purchase date.
RKNXCGE1YR Additional 1 Year Warranty
RKNXCGE2YR Additional 2 Year Warranty (Incl. Service Check at 40 Months
RKNXCGE3YR Additional 3 Year Warranty (Incl. Service Check at 40 Months)
UInity Kits
Part# Description Applicable Foot Kits
UTF0001 Unity TF Valve Kit All