ottobock 3R93 Modular Brake Knee Joint with Lock Instruction Manual

3R93 Modular Brake Knee Joint with Lock
Instruction Manual 3R93

3R93 Modular Brake Knee Joint with Lock

Explanation of symbols

WARNING Warnings regarding possible risks of severe accident or injury.
CAUTION Warnings regarding possible risks of accident or injury.
NOTICE Warnings regarding possible technical damage.
INFORMATION Important information on the fitting/use.

INFORMATION

Last update: 2021-07-26

• Please read this document carefully before using the product and observe the safety notices.
• Instruct the user in the safe use of the product.
• Please contact the manufacturer if you have questions about the product or in case of problems.
• Report each serious incident in connection with the product, in particular a worsening of the state of health, to the manufacturer and to the relevant authority in your country.
• Please keep this document for your records.

1 Single components (for reordering, Fig. 1)
1.1 Single components
(1) 2R77 Tube Adapter
(2) 710H10=2X3 Adjustment Wrench
1.2 Single-component pack
(3 a) 4F18=N Lock Slide, complete
(3 b) 4D30 Cable, complete (see Fig. 2, item A) 4D29 Knee Cap, complete
1.3 Accessories
(4) 4F34 Lock Control Unit
INFORMATION The accessories are not included in the delivery. They must be ordered separately.

Description

2.1 Intended use
The 3R93 Modular Friction Brake Knee Joint with Lock is to be used exclusively for the prosthetic fitting of lower limb amputees.
2.2 Field of application
Field of application according to the Ottobock MOBIS Mobility System:
Recommended for amputees with Mobility Grades 1 and 2 (indoor walkers and restricted outdoor walkers). Approved for a patient weight of up to 125 kg
The 3R93 Modular Friction Brake Knee Joint with Lock is not suitable for patients with:

• Hip disarticulation;
• Hemipelvectomy;
• bilateral transfemoral amputations.

2.3 Environmental conditions

(e.g. talcum)

2.4 Safety instructions
Please make your patients aware of the following safety instructions:
CAUTION
Reuse on another patient Risk of injury due to loss of functionality as well as damage to the product
Only use the product for a single patient.
CAUTION
Risk of falling as a result of excessive strain. The Ottobock prosthetic components described here have been developed for prosthesis wearers with Mobility Grades 1 and 2 and must not be used by prosthesis wearers with higher mobility grades. Otherwise, malfunctions of the joint can occur which may result in breakage of load-bearing or functionally relevant parts. This can cause the patient to fall.
Careful handling of the prosthesis and its components not only increases their service life but, above all, ensures the patient’s safety. Should prosthetic components be subjected to unusual stresses (such as a fall), immediately contact your prosthetist and have the components inspected for any damage. If necessary, the responsible prosthetist will pass the prosthesis on to Ottobock Service.
CAUTION
Malfunctions caused by using inappropriate prosthetic components. The 3R93 Knee Joint may only be combined with prosthetic components intended for the use with it.
CAUTION
Risk of falling due to incorrect environmental conditions. Using the knee joint in incorrect environmental conditions can lead to malfunctions of the joint up to loss of functionality due to structural failure. This can cause the patient to fall.
Prosthetic components must not be exposed to corrosive elements such as fresh water, salt water and acids. Penetration of liquids, dust, sand, etc. as well as the use of the knee joint at places with excessive ambient moisture must be avoided.
CAUTION
Risk of pinching in the flexion range area of the joint. It must be explicitly pointed out to the prosthesis wearer that there must not be any fingers/body parts in this area when flexing the joint.
NOTICE
Risk of damage due to incorrect environmental conditions. Prosthetic components must not be exposed to corrosive elements such as fresh water, salt water and acids. Penetration of liquids, dust, sand, etc. as well as the use of the knee joint at places with excessive ambient moisture must be avoided. Using this medical device in such environmental conditions will render all claims against Otto Bock HealthCare null and void.
INFORMATION
Use parallel bars for the first trial walk of the prosthesis wearer with the knee joint.
2.5 Construction and function
The 3R93 Knee Joint is a monocentric knee joint with a load-dependent brake mechanism and an optional locking function.
Due to its construction, the 3R93 can be used as a locked knee joint with manual lock release (pulling the pull cable) and as a friction brake knee joint once the prosthesis wearer has regained increased mobility (locking function permanently deactivated).
The 3R93 is especially suited for transfemoral amputees who are able to walk to a limited degree and who require a high degree of stability.
Locking function
The locking function can be permanently deactivated by the prosthetist (see Section 4.2.1). With activated locking function (delivery status), the lock mechanism, which is installed in the upper joint section, secures the joint in the extended position, and the latch engages. Flexion release (e.g. for sitting down) is activated by pulling the cable, which is attached to the cord loop. To do so, the patient either relieves the load on the prosthesis or applies load on the toes (knee extension moment) while unlocking the joint. Once the joint is unlocked (cable pulled), the patient can initiate the flexion movement. For safety reasons, activation of flexion release becomes more and more difficult with increasing flexion moment.
A hinged plastic flap (Fig. 2, item A) covers the anterior joint space even when the knee joint is in the maximum flexion position and protects the cosmetic foam cover and fingers from getting jammed.
Braking function
With permanently deactivated locking function, knee stability is achieved through the brake mechanism that blocks the joint in the flexion direction under load.
When load is applied to the heel, the brake responds, stabilises the prosthesis and achieves a high degree of stability throughout the entire stance phase. The brake also offers the desired security when walking with a slightly flexed knee joint. The braking effect is adjustable (see Section 4.2.2). Due to its construction, the brake mechanism does not wear down and is functionally reliable, so that readjusting the braking effect later is generally not necessary.
Swing phase control
The 3R93 Knee Joint has a mechanically controlled swing phase. To initiate the swing phase the prosthesis wearer relieves the load on the prosthesis to cause the brake to turn off. The integrated, adjustable spring extension assist (Fig. 2, item B) controls the pendulum movement of the prosthetic lower leg.
2.6 Combination possibilities
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.

Technical data

Handling

4.1 Alignment
CAUTION
Risk of falling as a result of incorrect alignment. Errors during the alignment of the prosthesis can lead to malfunction of the joint up to loss of functionality due to structural failure. This can cause the patient to fall. Observe the alignment instructions.
The advantages of the 3R93 can only be made optimal use of in case of a correct alignment. The optimal residual limb position must be anticipated when positioning the socket connector (Fig. 8). Plumb lines in the frontal and sagittal planes, drawn from the hip joint centre of rotation and marked while taking the plaster cast and during trial fitting of the test socket, will facilitate correct positioning of the lamination anchor or socket adapter.
To align the prosthesis please proceed in two steps: First make the bench alignment using an alignment tool such as 743L200 L.A.S.A.R. Assembly or 743A200 PROS.A. Assembly. For subsequent static alignment optimization, please use 743L100 L.A.S.A.R. Posture.
4.1.1 Bench alignment with alignment tool (Fig. 8)
Use 2Z11=KIT
INFORMATION
The connection area of the prosthetic knee joint can be protected against scratches with the protective film of the 2Z11=KIT during alignment in the workshop and testing in the trial fitting area.

• Use the protective film as illustrated in the accompanying document for the 2Z11=KIT.
• Remove the protective film before the patient leaves the fitting area.

1. Position the middle of the foot (MF) approx. 30 mm anterior to the alignment reference line. This applies to all foot components that are recommended for use with 3R93, independently of the specifications in the Instruction for Use of these feet!

2. Add 5 mm to the required heel height. Set correct outward rotation of the foot.

3. Clamp the knee joint using the appropriate adapter insert. Place the alignment reference point (= knee axis) 10 mm posterior to the alignment reference line. Take into account the knee-ground distance and outward rotation of the knee (the adapter insert in the alignment tool provides for a rotation of approx. 5°). Recommended sagittal positioning of the alignment reference point: 20 mm above the medial tibial plateau.

4. Connect the prosthetic foot to the modular knee joint using the enclosed 2R77 Tube Adapter (see Fig. 1, item 1).
   CAUTION
   Risk of falling due to incorrectly mounted tube adapter. Incorrect mounting of the tube adapter in the tube clamp (e.g. when using the insertion depth for length adjustment) can lead to excessive load on the tube clamp and to insufficient force transmission and as a result cause the patient to fall.
   An insufficiently secured connection between the tube adapter and prosthetic foot will also lead to a risk of falling. Observe the following instructions.
   a. Do not clamp the tube into a vice! Cut the tube using 719R2 Tube Cutter placed at a right angle to the tube.
   NOTICE
   Risk of damage to the prosthesis: For reasons of structural strength, the residual pieces of cut tube adapters must not be used as components in prostheses.
   b. Afterwards carefully deburr the inside and outside of the tube using the 718R1 Tube Deburring Knife.
   c. Do not make any length adjustment by varying the insertion depth. Insert the tube into the knee joints` tube clamp all the way to the stop.
   d. Tighten the cap screw of the tube clamp using the 710D1 Torque Wrench. Torque: 10 Nm (Fig. 2, item D).
   e. Connect the tube adapter to the foot. To do so, tighten the 506G3 Set Screws which are located next to each other at the distal end of the tube adapter using the 710D4 Torque Wrench. Torque: 10 Nm. (For completion of the prosthesis, apply 636K13 Loctite® to the set screws and tighten all set screws with 15 Nm).

5. Mark the centre of the socket proximally and distally on the lateral side. Draw a line through both marks from socket brim to the distal end of the socket.

6. Now position the socket such that the alignment reference line passes through the proximal centre mark. Set the socket flexion to somewhere between 3° and 5° taking the individual situation (e.g. hip flexion contractures) and the ischial tuberosity to ground distance into account.
   CAUTION
   Risk of falling as a result of incorrect alignment. If residual limb flexion is not taken into account, the joint will be positioned too far to the front. This can lead to malfunction and premature wear and cause the patient to fall.

7. Connect the socket and modular knee joint using a corresponding adapter (e.g. 4R111, 4R41, 4R55, 4R51 Socket Adapter). Use the 4R112 Sliding Adapter for alignment optimization (Fig. 10). When using socket adapters with a 4-hole connection (e.g. 5R1=, 5R6=), the 4R118 Sliding Adapter can be used for a permanent, additional posterior placement of 10 ­ 25 mm (Fig. 11).

4.1.2 Static alignment optimization with 743L100 L.A.S.A.R. Posture (Fig. 9)
After bench alignment of the prosthesis, static alignment using the L.A.S.A.R. Posture is carried out. In order to ensure appropriate stability combined with easy initiation of the swing phase, please proceed as follows:

1. To make the load line visible, the transfemoral amputee (with shoes) stands on the L.A.S.A.R. Posture with the prosthetic side on the force plate and with the other leg on the height compensation panel. The prosthetic side should be sufficiently loaded (> 35% of the body weight).
2. Now adapt the alignment by only adjusting the plantar flexion so that the load line (laser line) is 40 mm anterior to the alignment reference point (= knee axis) (see Fig. 9).

4.1.3 Dynamic alignment optimization
Perform dynamic optimisation during trial walking. Often, the following aspects have to be observed and adapted, if necessary:

• Socket flexion position by verifying step length symmetry (sagittal plane)
• Adduction position of the socket and M-L positioning of the socket adapter (frontal plane)
• Rotation position of the knee axis and outward rotation of the prosthetic foot (transversal plane) Finally, document the fitting result using for example the “Dartfish” motion analysis software.

4.2 Adjustments and final assembly
CAUTION
Risk of pinching. When adjusting and assembling the knee joint, there is a risk of pinching in the flexion range area of the knee joint. Do not reach into the flexion range area.
CAUTION
Risk of falling during trial walking. For safety reasons, the first steps of the prosthesis wearer should always be taken between parallel bars.
4.2.1 Deactivating/Activating the locking function
CAUTION
Risk of falling. It is very important to inform the patient about the changed functionality of the knee joint after deactivating the locking function.
Upon delivery, the locking function is permanently activated. Similar to conventional knee joints with lock it can be manually released with the pull cable (Fig. 2, item E), e.g. for sitting down.
Deactivating the locking function (permanently )

1. Using a screwdriver, carefully remove the blue-silver 4G551 Cover Cap which is located on the joint`s left side (in walking direction) (Fig. 4, item A).
2. Fully extend the knee joint.
3. Unscrew the 506G3=M4x18 Set Screw (Fig. 5, item A) using 710H10=2X3 Adjustment  Wrench (Fig. 5, item B).
4. Apply 636K13 Loctite® to the 506G3=M4x18 Set Screw and ­ while simultaneously pulling the cable (Fig. 5, item C) ­ use 710H10=2X3 Adjustment Wrench to clockwise screw in the screw up to the stop. The 4G539 Latch (Fig. 5, item D) can then no longer engage in its original position after letting go of the cable.
5. Reattach the cover cap. Now the locking function is permanently deactivated. The lock will no longer engage when the joint reaches full extension. Stance phase stability is now provided by the brake mechanism.

Activating the locking function
It may become necessary to reactivate the locking function due to decreasing mobility of the patient:

1. Using a screwdriver, carefully remove the blue-silver 4G551 Cover Cap which is located on the joint`s left side (in walking direction) (Fig. 4, item A).

2. Unscrew the 506G3=M4x18 Set Screw (Fig. 5, item A) counter-clockwise using 710H10=2X3 Adjustment Wrench (Fig. 5, item B).

3. Apply 636K13 Loctite® to the 506G3=M4x18 Set Screw and screw in again, but only to the extent that the 4G539 Latch (Fig. 5, item D) engages when reaching full extension.
   CAUTION
   Risk of falling. If the set screw is screwed in too much, this may impede correct use of the locking function, because the latch cannot engage. Screw in the set screw only to the extent that the movement of the latch when pulling the cable is not impeded.

4. Reattach the cover cap.

Lock slide and pull cable
In order to enable the patient to walk with the knee joint in free motion, the lock slide (Fig. 1, item 3a) is designed so that it can be secured also in the unlocked state. The lock slide should be mounted on the lateral side of the socket.
For mounting the lock slide on the socket, the perlon cord (Fig. 1, item 3b) should be shortened so that the complete pull cable (Fig. 1, item 3b) will be slightly tensed in the mounted state. The joint lock should unlock only after a pull cable stroke of approx. 10 mm.
CAUTION
Risk of falling if the lock does not properly engage. If the pull cable has been mounted incorrectly (lock opens unintentionally at knee flexion moment; lock does not engage at full extension), the knee joint might flex unintentionally what can cause the patient to fall. Test the locking function after all adjustments.
4.2.2 Fabricating a socket with lock slide and pull cable
INFORMATION
Please note that, when laminating the dummy, the threaded plate to hold the lock slide also has to be laminated into the socket. These should be centred in the matrix thickness.
Preparation for lamination

1. Pre-cut the thread in the threaded plate with an M4 thread cutter (Figure 12). The threaded plate is used to mount the lock slide.

2. Fill the bore in the threaded plate with plastaband (Figure 13).
   Laminating
   The channel is laminated into the socket with the help of the 21A18=4 dummy (not included in the scope of delivery).

3. Pull a PVA film over the plaster positive (Figure 14).

4. Depending on the body weight and load, pull several layers of nylglass and carbon over the PVA film.

5. Isolate the dummy for the channel with silicone grease and position it (Figure 15). The channel should be positioned so that the pull cable can be connected to the latch of the knee joint in a straight line at both ends after completion.

6. Position the threaded plate on the lateral socket side in a position that is easy for the patient to reach (Figure 15).

7. Laminate the threaded plate into the socket. A sufficient laminate thickness must be chosen so that the threaded plate does not turn later on while completing the thread cutting process.

8. Apply the remaining layers of nylglass and carbon (Figure 16). The dummy and threaded plate should be centred in the matrix thickness.

9. Laminate the socket in the usual way and allow it to set.

10. Trim and grind the socket.

11. Remove the dummy (Figure 17).

12. Drill out the plastaband from the threaded plate with a 3.2 mm drill bit (Figure 18) and finish cutting the thread with an M4 thread cutter.
    Mounting the lock slide

13. Mount the lock slide on the socket (Figure 19).
    Mounting the pull cable

14. Attach the karabiner to the latch. The opening of the karabiner faces the joint (Figure 20).

15. Thread the pull cable through the resulting channel in the laminate (Fig. 21).

16. Push the pull cable through the bore in the lock slide. Determine the length of the pull cable and cut it to length (Figure 22).

17. Thread the screw bushing onto the end of the pull cable (Figure 23).
    The lock slide is mounted correctly if the two ends of the pull cable point to the connecting points on the lock slide and on the knee joint pull strap in a straight line (Figure 24).
    Verification of functionality
    CAUTION
    Risk of falling if the lock does not engage properly. If the pull cable has been mounted incorrectly (lock opens unintentionally at knee flexion moment, lock does not engage at full extension), the knee joint may flex unintentionally and cause the patient to fall. Verify the locking function after all adjustments.

18. Check whether the joint reaches full extension with the pretension of the pull cable (Figure 25). 19. Check whether the lock release is easy to operate.
    Deactivating the locking function
    CAUTION Risk of falling. It is essential to advise the patient that temporarily deactivating the locking function with the lock slide can result in unsafe situations (intervention in the functionality).
    INFORMATION
    To permanently deactivate the locking function in the course of rehabilitation, proceed as described in Section 4.2.1.
    The locking function can be temporarily deactivated with the help of the lock slide. A modification of the lock slide is required in order to do so.

19. Unscrew the lock slide from the socket.

20. Open the supplementary guide on the lock slide by trimming the plastic lugs (Fig. 26).

21. Mount the lock slide on the socket.

    Now the joint can be temporarily unlocked and locked by engaging the lock slide (Figure 27).

4.2.3 Adjusting the braking function
CAUTION
Risk of falling due to incorrect brake function setting. I n case of incorrect brake function setting, the knee joint might flex unintentionally or the brake may get stuck, which may cause the patient to fall.
The sensitivity of the brake must be set such that a sufficient braking effect is guaranteed and the brake does not get stuck when the prosthesis is unloaded. Observe the following adjustment instructions.
Factory setting of the sensitivity of the brake is such that in general it does not have to be adapted to the patient. If required, however (e.g. in case of higher body weight), the sensitivity of the brake can be adjusted by turning the adjustment screw (Fig. 6, item A) using an Allen wrench (size 4 mm).
Before adjusting, flex the joint and open the front, blue cover cap (Fig. 6, item C). Upon delivery the adjustment screw is set to level 4 of the scale (highest brake sensitivity).
Turn the adjustment screw clockwise by one turn at most in order to reduce brake sensitivity. The patient must be sitting when making this adjustment:

Relevant especially for patients witha high body weight: Braking effectis too aggressive; initiation of theswing phase is difficult.| Brake sensitivity is set
too high.| Reduce brake sensitivity: Turn adjustment screw clockwise.
Relevant especially for patients with a low body weight: Braking effect is insufficient; the joint becomes unstable in the stance phase.| Brake sensitivity is settoo low.| Increase brake sensitivity: Turn adjustment screw
counter-clockwise. (Delivery condition = level 4 = highest brake sensitivity. Do not turn the
screw counter-clockwise any further!)

4.2.4 Adjusting the brake tolerance
CAUTION
Risk of falling after adjusting the brake tolerance. Adjusting the brake tolerance can cause the brake to get blocked or stuck and, as a result, cause the patient to fall. Observe the following instructions.
The adjustment is made by slightly turning the play compensation screw.
Adjusting the play compensation screw (Fig. 6, item B):

• Fully unscrew the 506G37-M5X5 set screw (Fig. 6, item D).
• Turn slightly using the 710H10=2X3 adjustment wrench (Fig. 1, item 2).
• Clean the set screw and apply Loctite (636W60).
• Install the set screw (tightening torque 2 Nm).

Flexion and extension movements are impeded when the prosthesis is unloaded (noticeable resistance to movement); the brake gets stuck.| Brake tolerance upon load bearing is too low.| Increase brake tolerance: Carefully turn the tension compensation screw clockwise.
Uncomfortable, jerky flexion andextension movements upon loadbearing| After longer use, thebrake tolerance upon  load bearing is too high.| Reduce brake tolerance: Carefully turn the tension compensation screw counter-clockwise.

Optimum setting (as delivered) is achieved, when there is no noticeable brake play upon load bearing and the pendulum movement of the prosthetic lower leg is not impeded during the swing phase.
4.2.5 Adjusting the swing phase control
The mechanical swing phase control of the 3R93 can be set to 6 levels by changing the tension of the integrated spring extension assist using 710H10=2X3 Adjustment Wrench (Fig. 1, item 2). Upon delivery the spring adjustment ring (Fig. 7, item A) is set to level 1.
If necessary, the spring effect can be adjusted as follows:

Lower prosthetic leg swings back too far; lower prosthetic leg does not reach extension position in time prior to heel strike.| Spring tension is set too low.| Increase spring tension: Insert the adjustment wrench at the spring adjustment ring and turn counterclockwise; the spring adjustment ring will engage with the next level.
Lower prosthetic leg does not swing back far enough; initiation of the swing phase is too difficult; acceleration of the lower prosthetic leg towards the extension stop is too high.| Spring tension is set too high.| Decrease spring tension: Insert the adjustment wrench at the spring adjustment ring and turn clockwise; the spring adjustment ring will engage with the next level.
(Delivery condition = level 1 = lowest spring tension. Do not turn the adjustment ring clockwise any further!)

4.3 Foam cover
The 3S107 or 3S106 Foam Cover can be used for the 3R93.
CAUTION
Risk of falling when using talcum powder. Talcum powder reduces the lubrication of the mechanical parts, which may lead to considerable malfunctions and result in brake function failure and thereby cause the patient to fall.
Do not use talcum powder. Using this medical device after application of talcum powder will render all claims null and void.
INFORMATION
An alternative for eliminating friction noises between the foam cover and prosthesis is a silicone spray (519L5) that can be sprayed directly onto the friction surface of the foam cover.
4.4 Maintenance instructions
Please make your patients aware of the following safety instructions:
CAUTION
Risk of injury as a result of excessive strain. The knee joint function may be affected by both environmental and service conditions. To reduce the risk for the patient, the knee joint must not be used when noticeable functional changes occur.
Noticeable functional changes may include poor response, incomplete extension, diminished stance phase stability, deteriorating swing phase behaviour, abnormal noises, etc. Measure: Have the prosthesis inspected by a prosthetist.
NOTICE
Risk of damage caused by improper cleaning agents. The use of aggressive cleaning agents must be avoided. They may cause damage to bearings, seals and plastic parts. Do not disassemble the joint! If you have a problem, please send the joint to Ottobock.
INFORMATION
When using exoprosthetic knee joints, servomotor, hydraulic, pneumatic or brake load dependent control functions can cause movement noise. This kind of noise is normal and unavoidable. Usually, it does not cause any problems.
If movement noise increases noticeably during the life cycle of the the knee joint, the joint should be inspected by a prosthetist immediately.
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. Ottobock recommends readjusting the knee joint settings once the patient has gotten used to the prosthesis. This period of time varies depending on individual patient characteristics. Please check the knee joint for wear and proper function once a year and make adjustments, if necessary. Special attention should be paid to movement resistance, changed brake tolerance and abnormal noises. Full flexion and extension must be guaranteed. Do not disassemble the joint. If you have a problem, please send the complete joint to Ottobock for repair.

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

All legal conditions are subject to the respective national laws of the country of use and may vary accordingly.
6.1 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 disregard of this document, particularly due to improper use or unauthorised modification of the product.
6.2 CE conformity
The product meets the requirements of Regulation (EU) 2017/745on medical devices. The CE declaration of conformity can be downloaded from the manufacturer`s website.

*ISO 10328 – P6 – 125 kg)*
) Body mass limit not be exceeded !
For further details see manufacturer’s written instructions on intended use !
Ottobock SE & Co.KGaA
Max-Näder-Straße 15
37115 Duderstadt/Germany
T +49 5527 848-0
F +49 5527 848-3360
healthcare@ottobock.de 
www.ottobock.com

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