Ossur TOTAL KNEE 1900 Gebrauchsanweisung Seite 9

2. On the anterior side of the device, turn the Friction Adjustment Screw
(8B) clockwise to increase the resistance to flexion and extension. Do
not exceed ¼ of a clockwise turn, which is the maximum setting for
the polymer friction (8C).
3. After obtaining the desired friction setting, tighten the Set Screw to
secure the polymer friction setting.
Caution: Do not overtighten the Set Screw. Apply 2 Nm (17 in-lbs) of torque.
Bumper adjustment
As needed, try different Bumpers, and select the one that best suits the
need of the patient.
The final bumper selection might differ from the initial selection based
on the patient's weight (please refer to the previous section: Bumper
Selection).
The torque required to release the Geometric Lock and the stance flexion
motion:
• increases when using a soft Bumper, and
• decreases when using a firm Bumper.
Depending on which foot is selected, combine:
• softer bumper with soft heels, and
• firmer bumper with firm heels.
Bumper height adjustment
A thin plastic plate, or a Shim (Fig. 7B), is placed underneath the Bumper
(7A) to adjust its height. There are two types of Shims:
• Grey: 0.38 mm thick, and
• Clear: 0.76 mm thick (the device is shipped with the Clear Shim
installed).
Adding Shims changes the release point of the Geometric Lock that
allows for knee flexion during the swing phase. Adjusting the height of
the Bumper affects knee stability, along with ease of walking and sitting:
• Higher Bumper: facilitates the release into swing flexion and
decreases stance flexion.
• Lower Bumper: increases the device's stability and stance flexion,
while delaying the release into swing flexion.
Gradually increase the height of the bumper until the patient feels
premature release of the knee. Reduce the number of Shims until the
patient finds a suitable balance between device stability and at which
point the knee releases into swing flexion.
Caution: Do not install more Shims than the two different types
combined. Adding more Shims can deactivate the Geometric Lock, and
negatively affect the stability of the knee during stance.
Note: If no Shims are used, the device will exhibit some flexion/extension
play during stance.
Extension Promoter
The Extension Promoter reduces excessive heel rise and promotes faster
knee extension. It is delivered in the minimum setting.
• Flex the knee to access the Extension Promoter Adjustment Screw (7D).
• To reduce excessive heel rise, especially when walking fast, turn the
Extension Promoter Adjustment Screw clockwise.
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