SQUARE KNOT
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Two-hand technique |
The two-hand square knot is the easiest and most reliable for tying most suture materials.
It may be used to tie surgical gut, collagen, surgical silk, dermal, virgin silk, surgical cotton and surgical
stainless steel. Standard technique of flat and square ties with additional throws if indicated by
surgicalr cumstance and the experience of the operator should be used to tie Coated VICRYL. (polyglactin 910) suture, PDS, II (polydioxanone) suture, ETHILON* nylon suture, ETHIBOND*
Extra polyester suture and PROLENE, polypropylene suture.
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1.
White strand placed over extended index finger of left
hand acting as a bridge, and held in
palm of left hand. Black strand
held in right hand.
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2.
Black strand held in right hand
brought between left thumb and
index finger. |
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3.
Left hand turned inward by pronation,
and thumb swung under white strand to form the first loop. |
4. Black strand crossed over white
and held between thumb and index finger of left hand.
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5.
Right hand releases black strand.
Then left hand supinated, with
thumb and index finger still grasping black strand, to bring
black strand through the white loop. Regrasp black strand
with right hand. |
6. Black strand released by left hand
and grasped by right. Horizontal tension is applied with
left hand toward and right hand away from
operator. This completes first half hitch.
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7.
Left index finger released from
white strand and left hand again
supinated to loop white strand over
left thumb. Black strand held in right
hand is angled slightly to the left. |
8.
Black strand brought toward the
operator with the right hand and
placed between left thumb and index finger. Black strand
crosses over white strand. |
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9.
By further supinating left hand,
white strand slides onto left index finger to form a loop
as black strand is grasped between left index finger and
thumb. |
10. Left hand rotated inward by pronation
with thumb carrying black strand through loop of white
strand.
Black strand is grasped between right thumb and index
finger.
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11.
Horizontal tension applied with
left hand away from and right hand toward the operator.
This completes the second half hitch. |
12.
The final tension on the final throw
should be as nearly horizontal as possible. |
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SQUARE KNOT |
One-hand technique |
Wherever possible the square knot is tied using the two-hand technic. On some occasions
it will be necessary to use one hand, either the left or the right, to tie a square knot. The
illustrations employ the left handed technic.
The sequence of throws illustrated is most commonly used for tying single suture strands.
The sequence may be reversed should the surgeon be holding a reel of suture material in
the right hand and placing a series of ligatures. In either case, it cannot be too
strongly emphasized that the directions the hands travel must be reversed proceeding from
one throw to the next to insure that the knot formed lands flat and square. Half hitches
result if this precaution is not taken
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1.
White strand held between thumb and
second finger of left hand with loop over extended index
finger. Black strand held between thumb and index finger
of right hand. |
2.
Black strand brought over white strand
on left index finger by moving right hand away from operator. |
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3.
With black strand supported in right
hand, the distal phalanx of left index finger passes under
the
white strand to place it over tip of left index finger.
Then the white strand is pulled through loop in
preparation for applying tension. |
4.
The first half hitch is completed by advancing tension in
the horizontal plane with the left hand drawn toward and
right hand away from the operator. |
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5.
White strand looped around three
fingers of left hand with distal
end held between thumb and index finger.
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6.
Black strand held in right hand brought toward the operator
to cross over the white strand. Continue hand motion by
flexing distal phalanx of left second finger to bring it
beneath white strand. |
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7.
As the second finger is extended
and the left hand pronated, the white strand is brought
beneath
the black strand. |
8.
Horizontal tension applied with
the left hand away and the right hand toward the operator.
This completes the second half hitch of the square knot.
Final tension should be as nearly horizontal as possible.
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SURGEON'S
or FRICTION KNOT
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The surgeon's or friction knot is recommended for tying Coated VICRYU (polyglactin 910) suture
and MERSILENE, polyester fiber suture.
The surgeon's knot also may be performed using a one-handed technique in a manner.
Analogous to that illustrated for the square knot one-hand technique.
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1.
White strand placed over extended
index finger of left hand and held in palm of left hand.
Black strand held between thumb and index finger of right
hand. |
2. Black strand crossed over white strand
by moving right hand away from operator at an angle to
the
left. Thumb and index finger of left hand pinched to form
loop in the white strand over index finger.
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3.
Loop of white strand slipped onto
left thumb. Black strand grasped between thumb and index
finger
of left hand. Release right hand |
4. Left hand rotated by supination
extending left index finger to pass black strand through
loop. Regrasp
black strand with right hand.
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5.
The loop is slid onto the thumb
of the left hand by pronating the pinched thumb and index
finger of
left hand beneath the loop. |
6. Black strand drawn left with right
hand and again grasped between thumb and index finger
of left
hand.
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7.
Left hand rotated by supination
extending left index finger to again pass black strand through
forming
a double loop. |
8.
Horizontal tension is applied with
left hand toward and right hand away from the operator.
This double loop must be placed in precise position for
the final knot. |
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9.
With white strand looped over thumb,
black strand is grasped between thumb and index finger of
left hand and held over white strand with right hand. |
10.
Black strand released. Left hand
supinates to regrasp black strand with index finger beneath
the loop
of the white strand. |
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11.
Black strand rotated beneath the
white strand by supinating pinched thumb and index finger
of left hand to draw black strand through the loop. Right
hand regrasps black strand to complete the second throw
square. |
12.
Hands continue to apply horizontal tension with left hand
away from and right hand toward the operator. Additional
throws are advisable for Coated VICRYL suture and MERSI-LENE
suture. Final tension on final throw should be as nearly
horizontal as possible. |
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DEEP TIE |
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Tying deep in a body cavity can be difficult. The square knot must be firmly snugged
down as in all situations. However the operator must avoid upward tension which may
tear or avulse the tissue.
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1.
Strand looped around hook in plastic
cup on Practice Board with index finger of right hand which
holds black strand in palm of hand. White strand held in
left hand. |
2. Black strand held in right hand
brought between left thumb and index finger. Left hand
turned inward by pronation, and thumb swung under white
strand to form the first loop.
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3.
By placing index finger of left hand
on white strand, advance the loop into the cavity. |
4. Horizontal tension applied by pushing
down on white strand with left index finger while maintaining
countertension with index finger of right hand on black
strand.
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5.
Black strand looped over and under
white strand with right hand. |
6.
Black strand looped around white strand
to form second loop. This throw is advanced into the depths
of the cavity. |
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7.
Horizontal tension applied by pushing
down on black strand with right index finger while maintaining
countertension on white strand with left index finger. Final
tension should be as nearly horizontal as possible. |
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LIGATION AROUND
HEMOSTATIC CLAMP |
Most common of two methods |
Frequently it is necessary to ligate a blood vessel or tissue grasped in a hemostatic clamp to achieve
hemostasis in the operative field.
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1.
When sufficient tissue has been
cleared away to permit easy passage of the suture ligature,
the white strand held in the right hand is passed behind
the clamp. |
2.
Left hand grasps free end of the
strand and gently advances it behind clamp until both ends
are of equalength. |
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3.
To prepare for placing the knot square,
the white strand is transferred to the right hand and the
black strand to the left hand, thus crossing the white strand
over the black. |
4. As the first throw of the knot
is completed, the assistant removes the clamp. This maneuver
permits any tissue that may have been bunched in the clamp
to be securely crushed by the first throw. The second
throw of the square knot is then completed with either
a two-hand or one-hand technique as previously illustrated.
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LIGATION AROUND
HEMOSTATIC CLAMP
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Alternate technique |
Some surgeons prefer this technique because the operator never loses contact with the
suture ligature as in the preceding technique.
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1.
Center of the strand placed in front
of the tip of hemostatic clamp with black strand held in
right
hand and white strand in left hand. |
2.
Black strand swung behind clamp and grasped with index finger
of left hand. Black strand will be transferred to left hand
and released by right. |
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3.
Black strand crossed under white strand
with left index finger and regrasped with right hand. |
4.
First throw is completed in usual
manner. Tension is placed on both strands below the tip
of the clamp as the first throw of the knot is tied. The
assistant then removes the clamp. The square knot is completed
with either two-hand or one-hand technique as previously
illustrated. |
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INSTRUMENT TIE |
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The instrument tie is useful when one or both ends of the suture material are short.
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1.
Short black strand lies freely.
Long white end of strand held between thumb and index finger
of left
hand. Loop formed by placing needleholder on side of strand
away from the operator. |
2.
Needleholder in right hand grasps
short black and of strand. |
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3.
First half hitch completed by pulling
needleholder toward operator with right hand and drawing
white
strand away from operator. Needleholder is released from
black strand. |
4.
White strand is drawn toward operator
with left hand and looped around needleholder held in right
hand. Loop is formed by placing needleholder on side of
strand toward the operator. |
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5. With end of the strand grasped
by the needleholder, black strand is drawn through loop
in the white strand away from the operator.
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6. Square knot completed by horizontal
tension applied with left hand holding white strand toward
operator and black strand in needleholder away from operator.
Final tension should be as nearly horizontal as possible.
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GRANNY KNOT |
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A granny knot is not recommended. However, it may be inadvertently tied by incorrectly crossing
the strands of a square knot. It is shown only to warn against its use. It has the tendency to
slip when subjected to increasing pressure.
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