Integra MAYFIELD A1108 Manuel D'instructions page 6

WARNING:
MAYFIELD Skull Clamp fixation devices are not
recommended for use on children under five
(5) years of age and extreme caution should be
exercised in pediatric cases because of the thin skull.
WARNING:
The skull clamp must be applied along the
centerline of the patient's head with pins
entering the skull perpendicularly. See Table
1. Failure to properly position the skull clamp on the
patient's head could result in patient injury such as
scalp laceration due to skull pin slippage. Failure to
properly position patient and to fully tighten and secure
all adjustable portions of this or any similar device may
restult in skull pin slippage and serious patient injury,
such as scalp laceration, skull fracture or even death.
a. Position the patient so that the two pins on the
rocker arm of the skull clamp are equidistant from the
centerline of the head (see Figure 2).
CAUTION:
Avoid the areas of the frontal sinus, temporal
fossa, major blood vessels, nerves, previously
restored or abnormally thin bone.
b. Pull the plunger out and slide the two halves of skull
clamp apart to adjust to proper width.
c. Place the clamp in the desired position, normally
perpendicular to the floor for supine or prone patient
positions and parallel to the floor for sitting patient
positions (see Figure 6).
d. The rocker arm is locked in place by rotating the index
knob clockwise 60 degrees until the arrow on the
index knob is aligned with the arrow on the aluminum
arm. The rocker arm is now fully locked (See Service
Note 2).
e. Seat the skull pins securely into the cranial table.
Skull pins should enter the scalp at a 90 degree angle,
perpendicular (or normal) to the head.
NOTE:
The single pin holder and torque screw give the surgeon a
visual readout of 20/40/60/80 pounds of clamping force
(see Figure 3).
NOTE:
The double pins on the rocker arm give the surgeon a
visual indication of clamping force (see Figure 5).
f. Clamping force is increased by turning the torque
screw clockwise (See Service Note 3). Turn the torque
screw to the desired graduation, then back off one
quarter turn.
g. If the pin carriers on the rocker arm are not displaying
an equal amount of clamping force (or the same
number of force indicator marks) the surgeon may
use the provided hex wrench to adjust the pin carrier.
If equal loading cannot be obtained by adjusting the
pin carrier, it is possible that the clamp is not properly
positioned on the patient's head (see Figure 6).
The carrier will not register additional
force beyond the fourth graduation
The pin carriers provide only a visual indication of force.
The carriers may be directly compared to achieve equal
force on both rocker pins.
CAUTION:
Adjusting the pin carriers will influence the
total force applied to the patient. After every
third adjustment made to the pin carrier, verify
the total force applied to the patient by looking at the
force gauge on the Torque Screw. The total force may be
higher or lower than its initial value.
Do NOT attempt to exceed the fourth graduation when
adjusting a pin carrier; see Figure 8.
NOTE:
A minimum of 60 lbs. of force must be applied to the
skull clamp. An additional force range reaching 80 lbs. is
available if desired.
WARNING:
Loading in excess of 80 lbs. is NOT
RECOMMENDED.
3. Mounting of the Skull Clamp
a. Insert threaded screw of small sunburst fitting on
the swivel adaptor into the threaded hole of the
MAYFIELD Base Unit's Transitional Member.
b. Turn the mounting knob clockwise and tighten.
c. Insert torque screw of the large sunburst ratchet on
the swivel adaptor into the threaded hole on the skull
clamp.
d. Turn the torque screw clockwise and tighten.
CAUTION:
Before fully tightening, always be certain that
the sunburst teeth of the Swivel Adaptor and
the Transitional Member fittings are the same
Page 6
Figure 8