ottobock 3R21 Polycentric Modular Knee Joints Instructions

ottobock 3R21 Polycentric Modular Knee Joints

Scope of delivery

Technical data

Dimensions required to fix it?

Bench alignment of the prosthesis

Optimising the static alignment

Optimising during dynamic trial fitting

Replacing the spring

Optimising during dynamic trial fitting

Increasing the axle friction

Maintenance

Explanation of warning symbols

CAUTION
Warning regarding possible risks of accident or injury.

NOTICE
Warning regarding possible technical damage.

Product description

The product (3R21, 3R30) has the following key features

• Polycentric prosthetic knee joint.
• Product components for stance phase stability.
• Polycentric kinematics.
• Product components for swing phase control.
• Extension assist (adjustable spring force, can be reduced by spring replacement.
• Adjustable friction brake as movement resistance for exten­sion and flexion.
• Material: Steel (3R21), Titanium 3R30.

Intended use

Indications for use

The product is intended exclusively for lower limb exo prosthetic fit­tings.

Area of application

CAUTION

• Excessive strain on the product
• Fall due to breakage of load bearing components.
• Only use the product according to its allowable field of applica­tion.

Allowable field of application 3R21, 3R30

Recommended mobility grade: 1 + 2| Everyday prosthesis
Allowable body weight: ≤ 125 kg

MG 1

Indoor walker

The patient has the ability or the potential to use the prosthesis for the purpose of moving or proceeding slowly on level floors. The amount of time and the distance he/she can walk are seriously lim­ited due to his/her condition.

MG 2

Restricted outdoor walker

The patient has the ability or the potential to walk slowly with the prosthesis and to negotiate low environmental obstacles like curbs, single steps or uneven surfaces. The amount of time and the dis­tance he/she can walk are seriously limited due to his/her condition.

Combination possibilities

CAUTION

Improper combination of prosthetic components

Injuries, malfunctions or product damage due to unallowable com­bination of prosthesis components. Based on the instructions for use of all prosthetic components used, verify that they may be combined with each other and are approved for the patient’s area of application.

INFORMATION

In a prosthesis, all prosthetic components have to meet the patient’s requirements regarding the amputation level, body weight, activity level, environmental conditions and field of application.

Unallowable combinations

Unallowable combinations

Prosthetic hip joints| All reference numbers

Environmental conditions

CAUTION

Use under unallowable environmental conditions.

• Fall due to damaged product.
• Do not expose the product to unallowable environmental condi­tions.
• If the product was exposed to unallowable environmental condi­tions, take suitable steps (e.g. cleaning, repair, replacement, inspection by the manufacturer or a specialist workshop etc.

Allowable environmental conditions

Allowable environmental conditions

Temperature range: Use: -10 °C – +45 °C

Storage

Transportation: -20 °C – +60 °C

Relative humidity: 20 % – 90 % Non-condensing
Commercially available solvent free cleaning agents

Unallowable environmental conditions

Unallowable environmental conditions

Storage/Transportation

Mechanical vibrations, Impacts

Hygroscopic particles e.g Talcum powder Dust, Sand, Fresh water, Salt water, Acids, Sweat, Urine
Cleaning agents containing solvents

Reuse and lifetime

CAUTION

Reuse on another patient

• Fall due to loss of functionality as well as damage to the product.
• Only use the product for a single patient.

Exceeding the lifetime

• Fall due to change in or loss of functionality and damage to the product.
• Ensure that the maximum lifetime defined in this section is not exceeded.
• This product was tested by the manufacturer with 3 million load cycles. Depending on the user’s activity level, this corresponds to a maximum lifetime of 5 years.

General safety instructions

Reaching into the area of the joint mechanism

Pinching of limbs e.g. fingers and the skin due to uncontrolled joint movement.

• Do not reach into the joint mechanism during daily use.
• Close attention is required during assembly and adjustment tasks.

Mechanical damage to the product of injury due to change in or loss of

functionality

• Use caution when working with the product.
• If the product is damaged, check it for proper function and readi­ness for use.
• In case of changes in or loss of functionality, do not continue using the product.
• Take any necessary measures e.g. repair, replacement, inspec­tion by the manufacturer’s customer service, etc.

Signs of changes in or loss of functionality during use

Changes in functionality can manifest themselves, for example, through a changed gait (swing phase, stance phase), incomplete extension, stiffness and the development of noise.

Scope of delivery

For the scope of delivery. A product component without a reference number in the illustration cannot be reordered separately. A reference number shown in bold in the illustration stands for a single component pack, in which the product components shown below it can be reordered.

Technical data

Proximal system height (PSH) : distal system height (DSH)

Preparing the product for use

Information on fabrication of a prosthesis

• Incorrect alignment, assembly or adjustment
• Injury due to incorrectly installed or adjusted as well as damaged prosthetic components.
• Observe the alignment, assembly and adjustment instructions.

CAUTION

• Initial use of the prosthesis by the patient
• Fall due to lack of patient experience, incorrect alignment or incor­rect adjustment of the prosthesis.
• For the safety of the patient, use a suitable device e.g. parallel bars, handrail, wheeled walker) during initial standing and walk­ing.

Bench alignment of the prosthesis

Improper assembly of the screw connections

Risk of injury due to breakage or loosening of the screw connec­tions

• Clean the threads before every installation.
• Apply the specified torque values.
• Follow the instructions regarding the length of the screws and about how to secure the screws.

INFORMATION
The prosthetic components and prosthesis shown in the illustrations are used as examples to illustrate the general process. The instruc­tions for use of the prosthetic components selected for the patient contain detailed information and have to be used for fabrication of the prosthesis.

• To enable the patient to stand safely, align the prosthesis using the alignment images well as the instructions for use of all prosthesis components used.
• Additionally, observe and the following points for the bench alignment of the prosthesis.
• Manufacture the prosthetic socket using the lamination anchor in such a way as to ensure safe use with respect to the patient’s body weight and level of activity.
• Regarding the definitive prosthesis, observe the instructions for securing the set screws in the lamination anchor.
• Secure the prosthetic socket to the lamination anchor using the screws and nuts supplied.
• To fabricate the definitive socket, Fabricat­ing the definitive socket.
• Create the prosthetic socket in such a way that only the marked area is used as a flexion stop.
• Remove protruding set screws   and replace them with shorter set screws.

Fabricating the Definitive Socket

The following instructions only apply to the KD variant of the product.

Required materials

• 4x501T1=M5X16 Slotted Truss Head Screw
•  4x 502R1=M5X16 Two Hole Nut
• 616G12* Carbon Fiber Woven Fabric
• 623T3* Perlon Stockinette, 616G13
• Woven Fiber glass Stockinette
• 617H19 Ortho cryl Lamination Resin
• 617H17 Ortho cryl soft
• 4G70 Lamination Anchor

Secure the connection between the lamination anchor and pros­thetic socket with the help of the truss head screws and two hole nuts.

INFORMATION
For stability, a different alignment of the carbon fibres and an overlap of 3 cm to the edge of the lam­ination anchor are important.

• Cut two pieces of carbon fibre cloth to size as a mat according to the edge of the lamination anchor.
• Position the two pieces on the lamination anchor.
• Cut a piece of Perlon stockinette to twice the length of the plaster.
• Twist the Perlon stockinette on the distal end and pull on the other half.
• Cut a piece of woven fibre glass stockinette to the corresponding length and pull on the length equal to two-thirds of the prosthetic socket.
• Tie off the woven fibre glass stockinette on the distal end and pull on the length equal to half the prosthetic socket.

The double casting process is used for lam­ination

• Cast the distal section of the prosthetic socket (2/3 of the length) with Ortho cryl lamination resin and allow it to cure.
• Cut a piece of Perlon stockinette to twice the length of the plaster positive and pull on one half.
• Twist the Perlon stockinette on the distal end and pull on the other half.
• Cast the prosthetic socket with Ortho cryl soft and allow it to cure.

Optimising during dynamic trial fitting

Adjusting the Settings

Fall due to incorrect or unfamiliar settings.

• Only adapt the settings to the patient gradually.
• Explain the effects of the adjustments on the use of the prosthes­is to the patient.

Adjusting the extension assist

• Increasing the spring tension.
• Reducing the spring tension.
• Replacing the spring

CAUTION
The lower leg of the prosthesis  must  not  swing through too far in the dorsal direction at the  beginning  of the swing phase. Adjust the extension assist so that the lower leg of the prosthesis swings through in the dorsal direction according to the patient’s requirements, but reaches full extension in a timely manner for the next heel strike. If necessary, substitute weaker spring in place of one that is too strong (see Fig.   6    on page 5).

Adjusting the swing phase friction

• Increasing the axle friction.
• Reducing the axle friction.

CAUTION
The prosthetic knee joint has to reach full extension, even at slower walking speed. Adjust the swing phase friction so that the prosthetic knee joint does not swing too hard against the extension stop and so that the prosthetic foot swings through sufficiently according to the needs of the patient.

Fine tuning the settings

CAUTION
The various settings of the prosthetic knee joint can­not be adjusted entirely independently of each other. When the settings cannot be fully adjusted to the comfort needs of the patient, the settings should be established primarily based on safety aspects. Adapt the settings of the prosthetic knee joint to the patient by means of fine-tuning and exercises. If the extension position is not reached with every step and at any walking speed, reduce the braking effect and/or increase the ini­tial tension of the extension assist. Check the adjustment of the prosthesis settings during normal consultations and the annual safety inspection. Advise the patient to check the prosthesis if changes in function occur.

Attaching the cosmetic cover

Use of highly hygroscopic particles grease absorbent sub­stances such as talcum. Risk of injury, damage to the product due to lack of lubrication. Do not allow the product to come into contact with highly hygro­scopic particles. After affixing the cosmetic elements, verify proper functioning of the prosthesis. To reduce friction and to eliminate noise, apply silicone spray dir­ectly onto the contact surfaces of the cosmetic foam cover.

Finishing the prosthesis

CAUTION
To avoid product damage and the risk of falling, finish the prosthesis by replacing set screws that are too short or too long, and by tightening all screw connections. In doing so, note the instructions for use for all prosthesis components regarding torque values and thread lock.

Use

Information for use

NOTICE

Mechanical overload

• Impaired functionality due to mechanical damage.
• Check the product for damage prior to each use.
• Do not use the product if its functionality has been impaired
• Take any necessary measures e.g. repair, replacement, inspec­tion by the manufacturer’s customer service, etc.

Cleaning

Use of unsuitable cleaning agents or disinfectants

• Impairment of functionality and damage due to incorrect cleaning agents or disinfectant.
• For the prosthesis, observe the cleaning instructions for all pros­thetic components.

INFORMATION

Clean the product if it gets dirty. For disinfection, only use disinfectants that do not affect the materials of the product. For further information, please consult the manufacturer.

• Clean the product with a damp, soft cloth.
• Dry the product with a soft cloth.
• Allow to air dry in order to remove residual moisture.

Maintenance

CAUTION
Failure to follow the maintenance instructions

Risk of injuries due to changes in or loss of functionality and dam age to the product

Observe the following maintenance instructions. Arrange regular maintenance intervals with the patient depending on the level of use. Following an individual period for the patient to get accustomed to the prosthesis, check the settings of the prosthetic joint and adapt them to the patient’s requirements again as needed. The prosthetic components should be inspected after the first 30 days of use. Inspect the entire prosthesis for wear during normal consultations. Conduct annual safety inspections. As part of the safety inspections, inspect the prosthetic joint for wear and proper functionality. Special attention should be paid to movement resistance, bearings and abnormal noises. Full flexion and extension must be ensured at all times.

Lubrication

The lubricants can be ordered from the manufacturer using the reference numbers. Use lubricants on the product sparingly. Replacing components. The components can be ordered from the manufacturer using the reference numbers address at the end of this document.

Disposal
In some jurisdictions it is not permissible to dispose of the product with unsorted household waste. Improper disposal can be harmful to health and the environment. Observe the information provided by the responsible authorities in your country regarding return, collection and disposal procedures.

Legal information

Liability

The manufacturer will only assume liability if the product is used in accordance with the descriptions and instructions provided in this document. The manufacturer will not assume liability for damage caused by disregarding the information in this document, particularly due to improper use or unauthorized modification of the product.

CE conformity
CE conformity The product meets the requirements of Regulation (EU) 2017/745 on medical devices. The CE declaration of conformity can be downloaded from the manufacturer’s website.

References

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