uniprox JT20 User manual

Polycentric Knee Joint
JT20 / JT20S / JT22 / JT22S
unique prosthetic solutions
A company of the Bauerfeind Group
Ein Unternehmen der Bauerfeind Gruppe – www.uniprox.de
Qualität und Fun tion
Gebrauchsanweisung
Instruction Manual
Uniprox GmbH & Co.KG
H.-Heine-Str.4
07937 Zeulenroda-Triebes
Tel. [phone]
Fax [phone]
E-Mail info @uniprox.de
Rev.0-2021-07_JT20, JT20S, JT22, JT22S_106634

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Please read the IFU carefully before fitting. nly correct usage will
warrant the function.
1. Intended Use
The nee joints are the connection between a prosthetic soc et and a modular
prosthetic limb prosthesis with polycentric nee function.
2. Technical data
2.1 JT 20 / JT22
•Material: Titanium, aluminium, plastic, stainless steel
•Pneumatic extension stop and swing phase control
•Integrated spring extension
•Variable Axis Geometrics
•Separate adj. of flexion and extension
•Distal attachment: 34 mm
•Max. weight: 150 g
•Mobility level: JT20: 2 / JT22: 2, 3
•JT22 with High Control Pneumatics
rder No. Material Installation height
(above the axis
center of rotation)
Weight Flexion
angle
Article No.
JT20-PYR Aluminium 15 mm / 132 mm 790 g 135° 4 170 010 01 00 000
JT20-M36 Aluminium 10 mm / 127 mm 790 g 135° 4 170 010 02 00 000
JT22-PYR Aluminium 15 mm / 132 mm 820 g 135° 4 170 010 11 00 000
JT22-M36 Aluminium 10 mm / 127 mm 820 g 135° 4 170 010 12 00 000
2.2 JT20S / JT22S
Similar nees as the JT20/JT22, though with adjustable, heel-activated flexible
Stance-Control (Bouncing) for additional stability.
2.3 Recommended Attachment
E-JT20-01 Pyramidadapter for JT20 / JT22
E-JT20-02 M36 Thread-adapter for JT20 / JT22
A30 34 mm Reduction Adapter to 30 mm tube
A86 Knee disarticulation anchor (waterproof)
A4-Ti400 Tube adapter 34 mm, length 400 mm
rder No. Material Installation height
(above the axis
center of rotation)
Weight Flexion
angle
Article No.
JT20S-PYR Aluminium 15 mm / 132 mm 790 g 135° 4 170 010 01 10 000
JT20S-M36 Aluminium 10 mm / 127 mm 790 g 135° 4 170 010 02 10 000
JT22S-PYR Aluminium 15 mm / 132 mm 820 g 135° 4 170 010 11 10 000
JT22S-M36 Aluminium 10 mm / 127 mm 820 g 135° 4 170 010 12 10 000
rder No. Material Weight Limit Weight Article No.
E-JT20-01 Steel < 150 g 80 g 4 170 001 00 22 001
rder No. Material Weight Limit Weight Article No.
E-JT20-02 Steel < 150 g 80 g 4 170 001 00 22 002
rder No. Material Weight Limit Weight Article No.
A30 Aluminium < 100 g 91 g 4 610 070 00 00 008
rder No. Material Weight Limit Weight Article No.
A86 Steel < 150 g 170 g 4 114 080 06 22 000
rder No. Material Weight Limit Weight Article No.
A4-Ti400 Titanium < 150 g 435 g 4 113 050 34 33 400

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3. Indication/ Contraindication
Indication:
•Transfemoral amputation
•Knee disarticulations
Contraindication:
•Residual muscular wea ness, contractures or proprioceptive dysfunction including
poor balance
•Inability to comprehend instructions
•Contra lateral joint instabilities or pathology
•Complicated conditions involving multiple disabilities
4. Side effects
There are no nown side effects.
5. General safety instructions
•This medical device is designed for single patient, multiple use.
•Fitting/service of this medical device is only allowed by a certificated orthopedic
professional.
•The professional should instruct the correct use of the device to the user.
•The joint must be protected against dust, moisture, aggressive media, and
mechanical forces so its function is not affected.
•The joint is intended for use at temperatures from -10°C to 50°C.
•Do not longer use the nee joint if its function is impaired. This may be due to
stiffness, restricted extension, noise generation, faulty swing phase control or
stance phase safety, as well as impact from an external force (for example, if
dropped). In such cases, it must be chec ed by a professional and, if necessary,
sent to Uniprox GmbH & Co. KG.
•There is a ris of jamming when the joint is in use.
•The product must not be changed or applied in any improper way. Non-compliance
can impair the function of the product and thus no liability will be accepted.
•The safety of the user is not guaranteed if the product is not used for its intended
purpose. This will also terminate the warranty of the product.
•Joint components may heat up slightly during wal ing.
•Silicone spray should be used to prevent noises being generated by contact
between the cosmetic foam and nee joint. Do not use Talcum powder as it removes
lubricant from the bearings and may lead to impaired function as a result.
6. Assembly
Polycentric nee joints with geometric loc ing, integrated pneumatic end stop
damping, and an adjustable mechanical spring extension assist to provide an
extension moment.
Additional for JT22/ JT22S:
•The pneumatic swing phase damping has an integrated nozzle valve for self-
adjustment per the individual user‘s wal ing speed.
•At low wal ing speeds, the nozzle valve offers slight damping resistance against
flexion of the lower leg. As the speed increases, there is an increase in
accumulated pressure before the nozzle, which increases the damping resistance
against flexion of the lower leg. The damping effect restricts flexion of the lower
leg. A high-performance extension unit accelerates the lower leg through the
extension phase until the adjustable end stop damping gently absorbs the
movement.
Additional for JT20S/ JT22S:
•The adjustable, heel-activated flexible Stance-Control (Bouncing) ensures
additional stability. At heel stri e at the start of the stance phase, the flexible
element of the posterior rod contracts, whilst the adjustable primary flexion
enabling a flexion angle of between 0° and 5° (bouncing). The intersection of the
connecting lines of the front and rear axles can be set closer together. With more
of the load being transferred to the prosthesis, the resulting instantaneous center
of rotation of the 4-axle joint lin chain experiences increasing dorsal-proximal
displacement and is thereby more secure against unintentional flexion.

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6.1 Alignment recommendation for JT20/ JT22
In principle, the prosthetic joint is secure for unintentional flexion if the load line
(plumb line runs from mid-trochanter) is 25 mm in front of the posterior upper axle.
Load line
in the middle third
of the foot
A possible variation on the above alignment recommendation would be to reduce rear
displacement of the posterior upper axle up to 10 mm with respect to the load line.
This only when the technical and individual requirements have been chec ed and
confirmed by an orthopedic technician. This reduction of posterior displacement
represents an exceptional scenario and requires the orthopedic technician to ma e a
decision on a case-by-case basis. When posterior displacement of the joint is reduced,
the amputee must be able to actively secure the prosthetic nee joint by extending the
stump at the amputation side. If it is not advisable to reduce posterior displacement in
various cases, there is a ris of unintentional flexion of the nee joint or loc ing, with
the amputee being exposed to the associated dangers. It is the orthopedic technician’s
choice and must carefully be monitored before a decision regarding reduction is made.
25 mm
Note: If the joint is tilted forward due to the set up of the foot, the joint
becomes less secure and must be shifted further backwards!
6.2 Alignment recommendation for JT20S/ JT22S
In principle, the prosthetic joint is secure against unintentional flexion if the load line
or lateral alignment line runs through the middle of the front upper axle (Plumb line
runs from mid-trochanter).
Load line
in the middle third
of the foot
A high-performance extension unit accelerates the lower leg through the extension
phase until the adjustable end stop damping gently absorbs the movement.
At heel stri e at the start of the stance phase, the flexible element of the posterior rod
contracts, with the adjustable primary flexion enabling a flexion angle between 0° and
5° (bouncing). This brings the joint axles closer together. With more of the load being
transferred to the prosthesis, the resulting instantaneous center of rotation of the 4-
axle joint lin chain experiences increased dorsal-proximal displacement and is
therefore more secure against unintentional flexion. The integrated flexible posterior
rod ensures a highly dynamic transition between the stance and swing phases.*

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If the mar ing of the axis is in position D, a higher initial dynamic setting of the
polycentric JT22/JT22S is achieved. In this case, the torque pivot point is more
distal/anterior.
1. Loosening the loc ing screw
2. Use a hexagonal wrench (SW4) to set the posterior lower eccentrically mounted
axis to S or D; an intermediate position is not permitted.
3. Secure the loc ing screw with Loctite 222 and tighten it to 12 Nm with a
hexagonal wrench (SW4).
Position S Position D
higher initial safety higher initial dynamics
The JT22/JT22S has two pole curves, which can be used to set a higher
initial safety level or a more dynamic initial movement setting of the
joint. In each case, the pole curve required can be adapted to suit
individual requirements by simply adjusting the eccentrically positioned
posterior lower axle.
6.4 Adjusting the flexion resistance
The integrated spring extension assist is used to adjust the mechanical swing phase
control. Flexion resistance can be changed by turning the upper set screw, mar ing F
(Fig. 4), with an Allen ey (SW 2 mm). Turn the screw cloc wise to increase flexion
resistance or countercloc wise to reduce it.
The JT20S and JT22S offer a better ground clearance during the swing phase.*
Since the flexible posterior rod has excellent tensile strength, it barely increases in
length when the stance phase ends and the swing phase begins.
* Since safety does not have to be established through the alignment, i.e. the lateral alignment line runs
through the middle of the front upper axle.
Note: If the joint is tilted forward due to the set up of the foot, the joint
becomes less secure and must be shifted further backwards!
6.3 Setting the pole curve
The nee joints have two pole curves that can be used to set a higher initial safety or
greater initial dynamics of the joint. The respective desired pole curve can be
individually adjusted by the anterior lower axis, which is eccentrically mounted.
By simply turning the eccentric, it is possible to switch from
a safe to a dynamic geometry:
"S" >> high stability
"D" >> greater dynamics.
If the mar ing on the axis is above the inner hexagon (position S), a high initial safety
setting of the nee joint is ensured.
In this case, the instantaneous center of rotation is further proximal/posterior.

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Turning the upper set screw (mar ing F) in a cloc wise direction
(maximum rotation is reached when a slight stop can be felt)
increases the flexion resistance.
Turning the upper set screw (mar ing F) in a countercloc wise
direction (maximum rotation is reached when a slight stop can
be felt) reduces the flexion resistance.
The lowest possible flexion resistance is pre-set in the factory settings.
6.5 Adjusting extension resistance
Extension damping is regulated by turning the lower set screw, mar ing E (Fig. 5).
Turn the screw cloc wise to increase extension damping or countercloc wise to reduce
it. The set screw must not be screwed out by more than 3 full rotations. Change the
setting incrementally, not exceeding a quarter of a rotation with any turn.
Turning the lower set screw (mar ing E) in a cloc wise
direction increases the extension damping.
Turning the lower set screw (mar ing E) in a countercloc wise
direction (up to 3 rotations) reduces the extension damping.
The lowest possible extension damping is pre-set in the factory
settings.
Adjust the extension damping before the first run test as follows:
Close the extension valve with an Allen ey cloc wise until you
feel the stop; then open the valve by half a turn. Starting with
this setting, readjust the extension damping in small steps
during the dynamic try-on.
Note: The extension valve must never be closed completely, as the
enclosed air cushion presses the joint into flexion. Danger of falling!
Complete joint extension must be guaranteed!
6.6 Adjusting the stance flexion control for the JT22S
The response threshold for activating the flexible rear handles can be set individually
for the user; this setting is weight-dependent.
Insert the adjustment ey at the bac of the joint onto the adjustment ring.
Turning cloc wise reduces the flexible stance control/
damping resistance of the flexible rear handlebar.
Turning countercloc wise increases the flexible level control/
the flexible rear handlebar damping resistance.
6.7 Adapter tightening torques
The 34 mm tube clamp of the nee joints must be secured with Loctite® 222 and
tightened with an Allen ey (SW 4) to a torque of 12 Nm.
The proximal adapter of the nee joints in the shape of a pyramid or the M36 thread
connection must be secured using Loctite® 222 as a thread loc ing compound and
tightened with an Allen ey (SW5) to a torque of 20 Nm.
MA=20 Nm

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Please direct any questions to:
Customer Service: + 49 (0) 36628-66-33 70
Fax: + 49 (0) 36628-66-33 77
E-mail: [email protected]
7. Maintenance and Cleaning
The function of the prosthetic nee joint must be chec ed at regular intervals of no
more than 12 months. For very active users, we recommend carrying out inspections at
shorter intervals.
Maintenance or repair must be carried out when necessary.
The polycentric knee joints can be cleaned with a mild cleanser and a
damp cloth at >30°C. Do not use any aggressive cleansers.
8. CE-Conformity
The product satisfies the requirements of Regulation (EU) 2017/745 of the European
Parliament and of the Council (MDR) and bears the CE mar . All major incidents related
to the product needs to be informed to Uniprox and the competence European
Authority.
9. Warranty and Guarantee
We recommend to change/renew the liner after 6 month of usage.
Warranty is provided under the terms of sale and supply of Uniprox GmbH & Co. KG
provided that the above conditions are met.
10. Storage and Disposal
This product has no special storage regulations.
The product is disposable with standard household garbage.