Comfort-Brake Knee (mech Ext. Assist) | Knees - Mechanical | Lower Limb Prosthetics | Prosthetics | Ottobock US B2B Site
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Comfort-Brake Knee (mech Ext. Assist)

Item #: 3R90

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Suggested HCPCS Coding: L5812 + L5845 + L5850
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The innovative load-dependent brake mechanism offers targeted safety for the patient. Heel strike activates the brake and provides high stability in the stance phase.

The swing phase can be controlled by means of a mechanical extension assist which, integrated in the lower section of the joint, has a progressively acting spring combination. Two combined spring elements form the integrated mechanical extension assist of the 3R90. The interaction of the springs results in an extension assist effect dependent on the knee angle. It can be preset to one of 5 different levels by means of a ratchet unit.

When fitting users with mobility grade 1, the following applies: these knee joints with friction brake are contraindicated for unsure patients who are unable to systematically use the braking mechanism during the gait cycle i.e. to lock the knee joint at heel contact and unlock it when the forefoot is loaded.


Scope of Delivery: 3R90 Knee + 2R77 Pylon

Activity Level K1, K2
Maximum Body Weight 275 lbs (125 kg)
Material Aluminum
Proximal Connection Pyramid Adapter
Distal Connection Tube Clamp
Maximum Knee Flexion Angle 135 degrees
Knee Center to Proximal Connection 40 mm
Product Weight 745 g

3R90 / 3R92 Brochure

Product Information: 646D338 (EN)

Published Date: July 1, 2016

3R90 / 3R92 Instructions for Use

Instructions for Use: 647G475 (EN/DE/FR/IT/ES/PT/SV/NL/DA/PL/HU/CS/RO/HR/EL/RU/TR/ZH/JA)

Published Date: July 13, 2020

Fabrication Order Form for Transfemoral or Knee Disarticulation

Order Form: (EN)

Published Date: May 1, 2015

LL Prosthetic Documentation Packet

Product Information: (EN)

Reimbursement: Documentation Guide

Published Date: July 20, 2020