Controlled release suture
I United States Patent 1 [ll] 3,875,946  
 Duncan Apr. 8, 1975 CONTROLLED RELEASE SUTURE [57] ABSTRACT [75] Inventor: Robert Barclay Duncan, Somerville. A needle-suture combination having a suture pull-out N value in the range of l to 26 ounces is manufactured by applying sufficient tension to the suture to move it [73] Assgnee&#39; Eamon Somervme&#39; relative to the needle barrel and releasing the tension [22] Filed: Feb. 27, 1974 when the force drops to within the following range for 1 pp No: 446,174 that size of suture:  
 [52} US. Cl. 128/339; 128/335.5; T6331}; suture size ounces [5 I] Int. Cl A6lb 17/06 8/0 I. 2. 581 Field of Search 128/3355, 339, 334 R; 33 5:12; 163/5, I; 223/l02 5/0 3. 7. :13 [56] References Cited 2/0 5: I Sei UNITED STATES PATENTS {31 5;; 2,240,330 4/194] Flugg et ul. l28/339 2 and &#34;2&#34; we 2.620.028 l2/l952 Kohut 163/5 2910.983 11/1959 Everett l28/339 3.799.l69 3/1974 Beroff et l28/339 Primary Examiner-Dalton L. Truluck Claims n Drawing Figures Attorney, Agent, or Firm-Wayne R. Eberhard! PATENTEUAPR ems SHLEI 1 [if 4 SHEEI 3 (IF 4 PATENTEU 8|975 CONTROLLED RELEASE SUTURE BACKGROUND OF THE INVENTION In many surgical procedures, surgeons use a tech- 5 nique which employs a non-needled suture and an eyed needle. The needle is threaded by the nurse and the surgeon takes one pass through the tissue using a needleholder. He slips the needle off the suture, returns the needle to the nurse, and is ready for another threaded needle from the nurse. An assistant follows behind and ties the suture.  
  Surgeons find that this technique is more simple than using a needled item and cutting the suture with a scissors after each pass. However, the time required for threading results in a significant waste of expensive operating room time.  
  The security of attachment of eyeless needles to absorbable surgical sutures or to nonabsorbable surgical sutures is prescribed in the U.S. Pharmacopoeia, Vol. XVIII at Page 944 (also see U.S. Pharmacopoeia, Vol. XVII, Page 919). It has been the practice of suture manufacturers in the United States and abroad to securely attach the suture to the needle by swaging or with an adhesive so that the minimum pull&#39;out standard recited in the U.S. Pharmacopoeia is met or exceeded. The conversion of the U.S. Pharmacopoeia minimum standard on needle attachment from kilograms to ounces is summarized in the following table.  
 TABLE I MINIMUM LIMITS ON NEEDLE ATTACHMENT Average Ounces 2 and larger It will be noted from the above table that separation of the suture from the needle is relatively easy if the suture is size 5/0 or smaller since the average force required is less than 8 ounces. On the other hand, the minimal average force required to separate a size 4/0 suture (diameter 7.0 mils to 9.5 mils) from the needle is about l6 ounces and because needles are swaged to make quite certain that the minimum U.S. Pharmacopoeia standards are met, many individual samples require forces in excess of 2 pounds to detach the needle from the suture.  
  There is a need for a needle-suture combination that has the convenience of the needle being preattached to the suture and yet permits separation of the needle from the suture without the necessity of cutting with a scissors.  
  One approach to this problem is described in copending application Ser. No. 252,l76, filed May II, 1972, now U.S. Pat. No. 3,799,169. This approach involves manufacturing the needle with an open channel at the blunt end thereof sized to receive a suture. The suture is bonded to the channel with an adhesive that prevents pull-out of the suture as it passes through tissue. After suturing, the surgeon may easily remove the needle from the suture by turning the needle so that the channel is at an angle of about to the direction of the suture and peeling the suture out of the channel.  
  This approach has one disadvantage in that many surgeons prefer a closed channel over an open channel needle because of the uniform cross&#39;section at the end of the needle and the smooth transition between the needle and the attached suture.  
  [t is an object of the present invention, therefore, to make available to the surgeon a needle-suture combination useful in suturing, and characterized by a needle-suture attachment that will permit facile removal of the needle from the suture without cutting the suture with a scissors.  
  Another object of this invention is to provide the surgeon with a needle-suture combination that will reduce the time that the surgical patient must spend in the operating room.  
  Yet another object of the invention is to provide the surgeon with a needle-suture combination that will permit separation of the needle from the suture after suturing by a slight pull upon the needle.  
 SUMMARY OF THE INVENTION Needle-suture combinations manufactured in accordance with the present invention are characterized by a suture pull-out value substantially lower than the minimum average force specified in the U.S. Pharmacopoeia. The process of the present invention permits better control of the end product in that the force required to separate a suture of a particular size from its attached needle is uniform. Thus, in any batch of needled sutures manufactured during a single production run, the variation of the pull-out value from the mean is reduced.  
  It is an advantage of the product of the present invention, therefore, that the surgeon may readily remove the needle from the suture by exerting a force less than that specified in Table I and thereby save the time previously required to cut the suture. The actual force required to remove the needle from the suture will vary with the suture size, but can be controlled within the following limits by the method to be described.  
  It will be noted from the above table that the pullout&#34; range is lower than that specified in the U.S. Pharmacopoeia and in no instance exceeds about 26 ounces.  
  The suture utilized in the present invention may be any known braided or monofilament suture materials, either absorbable, i.e., catgut, extruded collagen, a braided polyhydroxyacetic ester, a synthetic copolymer of L(-) lactide and glycolide&#39;, or non-absorbable, i.e., silk, nylon, polypropylene, cotton, linen, or polyester.  
  The needled sutures of the present invention are manufactured by conventional procedures. One end of a suture is inserted into a drilled needle, a channel needle or a preclosed channel needle and the needle is swaged to secure the suture. It has long been known that by proper control of the diameter of that end of the suture which is placed in the needle, the diameter of the needle hole and the swaging process, needled sutures can be manufactured that satisfy the minimum limits on needle attachment as set forth in the U.S. Pharmacopoeia.  
  It is also known that in swaging, excess force is to be avoided as over-swaging will weaken the suture strand and result in the suture breaking at the needle. In accordance with the present invention, the needled sutures are swaged so that the force required to pull the suture out of the needle exceeds the minimum limits on needle attachment set forth in Table I, but is less than the actual tensile strength of the suture used.  
  Preferably, the needles are swaged so that the suture may be pulled out of the needle by a force in the range of l to 6 pounds for size 4/0 suture and larger. If the suture is smaller than size 4/0, it is preferred that the needle be swaged so that the suture may be pulled out of the needle without breaking by a force in the range of 3 to ounces as indicated in the following table.  
 TABLE III Force in Ounces Required to Move Suture Relative Suture Size to the Needle Barrel The pull-out characteristics that distinguish the product of the present invention are obtained by prestressing the suture, i.e., tension is applied to the suture after the swaging step partially pulling the suture out of the needle. As the suture is pulled from the needle, the force required to move the suture relative to the swaged section decreases. When the force required to move the end of the suture relative to the needle barrel drops to the desired pull-out value, the tension is released.  
  It has been noted that if the bond between the needle and its attached suture is within the range set forth in Table II, the suture will not separate from the needle as the surgeon passes the needle through tissue. Yet, the needle can easily be removed from the suture at any time by simply pulling on the needle with a force of from I to about 26 ounces depending upon the suture size. Needle-suture combinations having the pull-out values summarized in Table II may be manufactured by applying sufficient tension to the suture to move it relative to the needle barrel, and then releasing the tension when the force drops to within the following range for that size of suture.  
 -Continued Suture Size Ounces 3/0 5 23. 2/0 5. 26. [/0 l0. 26. l 10. 26. 2 and larger 10. 26.  
  The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings which show by way of example preferred embodiments of the inventive idea.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged perspective view of a swaged and stressed needle-suture combination;  
  FIG. 2 is an enlarged perspective view of the needlesuture combination of FIG. 1 and illustrates removal of the needle from the suture;  
  FIG. 3 is an enlarged sectional view of a needlesuture combination;  
  FIG. 4 is an enlarged sectional view of the needlesuture combination of FIG. 3 showing displacement of the suture from the needle;  
  FIG. 5 is a diagram of apparatus useful in manufacturing the needled sutures of the present invention;  
  FIG. 6 is a graph of the displacement of a suture from the drilled hole as a function of the stress applied to the suture;  
  FIG. 7 is a graph of the displacement of a suture from the drilled hole as a function of the stress applied to the suture;  
  FIG. 8 is a graphic representation of the pull-out values determined on eleven prestressed needle-suture combinations;  
  FIG. 9 is a graph of the displacement of a suture from the needle hole as a function of the stress applied;  
  FIG. 10 is a graph of the displacement of a suture from the needle hole as a function of the stress applied;  
  FIG. 11 is a graphic representation of the pull-out values determined on ten needle-suture combinations.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with the present invention, needled sutures are manufactured in the conventional manner and prestressed to reduce the force required to separate the needle from the suture to a predetermined value. The resulting controlled release suture is then packaged and sterilized.  
  Prestressing may be accomplished by the apparatus illustrated in FIG. 5, which is designed to apply a stress to a needle 11 and the attached suture 12 sufficient to partially withdraw the suture from the needle. It includes in part an arm 13 fitted with a gate 14 sized to retain stationary the needle while permitting movement of the suture relative thereto. The arm is pivoted for movement around the pivot pin 15. A clamp 16 fitted with movable jaws l7 and 17&#39; is aligned with the gate and grips the suture. Movement of the clamp in the direction of the arrow applies stress to the suture causing it to move relative to the needle barrel 30 thereby displacing the end 18 of the suture from the bottom 20 of the needle hole by a distance 19 (see FIGS. 3 and 4).  
  The stress applied to the suture by the clamp is monitored by a force transducer 21 which acts with the clamp to stop the movement thereof when the applied stress drops to a predetermined value.  
  FIG. 6 illustrates the relationship between stress, strain, and the actual displacement of four size 0 black braided silk sutures as tension is applied to pull the sutures completely out of the needle. The sutures are swaged to a 39 mil drilled needle. The diameter of the drill hole is 19 mils and the depth of the drill hole (the length of the suture within the needle barrel) is 70 mils.  
  F IG. 7 illustrates the relationship between stress, strain, and the actual displacement of four size 0 black braided silk sutures as tension is applied to pull the sutures out of the needle. The sutures are swaged to a 39 mil drilled needle. The diameter of the drill hole is 19 mils and the depth of the drill hole (the length of the suture within the needle barrel) is 70 mils. In this instance, the sutures are not pulled completely out of the needle; when the tension drops to 1 pound, the movement of the clamp is stopped.  
  FIG. 9 illustrates the relationship between stress, strain, and the actual displacement of a size 0 polyester suture from a channel needle. The needle is made of 39 mil wire and has a channel length (prior to closure) of 178 mils.  
  As tension is applied to the suture by the clamp, the suture is elongated (about 0.02 inches) until the stress exceeds 6 pounds. At that point, the suture moves relative to the needle and the stress drops as the suture is withdrawn. Movement of the clamp is stopped when the stress reaches l pound at which point the displacement of the suture from the end of the needle channel is about 0.09 inches (about 50% displacement).  
  FIG. 10 depicts the relationship of stress, strain, and suture displacement when force is applied to a size 0 polypropylene suture swaged to a channel needle. The needle is made of 39 mil wire and has a channel length (prior to closure) 188 mils. In this instance, as the stress is increased to about 4 pounds, the suture is stretched about 0.02 inches. Increasing the stress above 4 pounds results in movement of the suture relative to the needle channel. Stress is removed when the force applied drops to l pound at which point the suture has been displaced from the channel needle a distance of about 0.08 inches (about 42% displacement).  
  The following examples will serve to further illustrate the invention.  
 EXAMPLE 1 Size 0 black braided silk suture strands are swaged to drilled needles manufactured of 39 mil wire and having a drilled hole in the blunt end l9 mils in diameter and 70 mils deep. The suture ends are inserted into the needles until they are in contact with the bottom of the drilled hole as shown in FIG. 3. The needles are then swaged so that the force required to pull out the suture is within the range of about from 2 to 5 pounds.  
  The swaged needle-suture combinations are prestressed in a Table Model lNSTRON Tensile Tester (Model TT-DL) using a Type CT Tension Cell (fullscale range 100 pounds), and the machine is set so that full-scale deflection is obtained at 20 pounds. Two line contact jaws are used to secure the needled sutures in the lNSTRON machine. The upperjaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 p.s.i. air pressure. The lNSTRON machine is operated at a cross-head speed of 0.] inches per minute and a chart speed of 5 inches per minute until the tension drops to one pound.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the lNSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the ten sutures is recorded below:  
 l4 ounces l4): ounces l3 ounces l3): ounces l4 ounces ll ounces 14 ounces 15 ounces 16% ounces [5 ounces The narrow distribution of pull-out values is graphically illustrated in FIG. 1 1.  
 EXAMPLE 2 Size 0 monofilament polypropylene suture strands are swaged to drilled needles manufactured of 39 mil wire and having a drilled hole in the blunt end 19 mils in diameter and mils deep. The ends are inserted into the needles until they are in contact with the bottom of the drilled hole as shown in FIG. 3. The needles are swaged so that the force required to pull the suture out of the needle is within the range of from about 3 to 5 pounds.  
  The swaged needle-suture combinations are prestressed in a Table Model lNSTRON Tensile Tester (Model TT-DL) using a Type CT Tension Cell (fullscale range pounds), and the machine is set so that full-scale deflection is obtained at 20 pounds. Two line contact jaws are used to secure the needled sutures in the lNSTRON machine. The upper jaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 p.s.i. air pressure. The lNSTRON machine is operated at a cross-head speed of 0.1 inches per minute and a chart speed of 5 inches per minute until the tension drops to l pound.  
  Eleven prestressed needle-suture combinations randomly selected from this production batch are replaced in the lNSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the l l sutures is recorded below:  
 17% ounces 16 ounces 17% ounces 16 ounces 17 ounces l7 ounces 17 ounces l7 ounces l ounces l7 ounces l8 ounces The narrow distribution of the pull-out values is graphically illustrated in FIG. 8.  
 EXAMPLE 3 A size 2 black braided silk suture strand is swaged to a channel needle manufactured of 39 mil wire. The length of the channel (the length of the suture within the needle barrel) is seven thirty-seconds inches. The needles are swaged so that the force required to pull out the suture is about 5 pounds.  
  The swaged needle-suture combination is prestressed in a Table Model lNSTRON Tensile Tester as described in Example 1 above, until the tension required to pull the suture from the needle drops to 21 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the INSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the 10 sutures is recorded below:  
 l4 ounces l7 ounces l5 ounces l8 ounces 22 ounces 2] ounces l4 ounces 20 ounces l6% ounces 26 ounces EXA M PLE 4 A size 1 black braided silk suture strand is swaged to a drilled needle manufactured of 32 mil wire and having a drilled hole in the blunt end 22 mils in diameter and 70 mils deep. The end of the suture is inserted into the needle until it is in contact with the bottom of the drilled hole as shown in FIG. 3. The needle is then swaged so that the force required to pull the suture out of the needle is within the range of about from 3 to 6 pounds.  
  The swaged needle-suture combination is then prestressed in a Table Model INSTRON Tensile Tester (Model TT-DL) using a Type CT Tension Cell (fullscale range 100 pounds), and the machine is set so that full-scale deflection is obtained at 20 pounds. Two line contact jaws are used to secure the needled suture in the INSTRON machine. The upper jaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 p.s.i. air pressure. The INSTRON machine is operated at a cross-head speed of 0.1 inches per minute and a chart speed of 5 inches per minute until the tension drops to 20 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the INSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the i sutures is recorded below:  
 15 ounces 20 ounces 16 ounces 24 ounces 15 ounces 2l ounces 1% ounces l9 ounces 16% ounces 22 ounces EXAMPLE Size 3/0 black braided silk suture strands are swaged to channel needles manufactured of 22 mil wire and having a channel in the blunt end five thirty-seconds inch in length (five thirty-seconds inch suture engagement). The needles are swaged to close the channel so that the force required to pull out the suture is within the range of about from 1 to 2 pounds.  
  The swaged needle-suture combinations are prestressed in a Table Model INSTRON Tensile Tester as described above until the tension drops to l 1 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the INSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the ID sutures is recorded below:  
 ll ounces l2 ounces 8 ounces 8 ounces 7 ounces 9 ounces l ounces 8 ounces l3 ounces 7 ounces EXAMPLE 6 Size 4/0 black braided silk suture strands are swaged to channel needles manufactured of 17 mil wire (suture engagement nine sixty-fourths inches). The needles are swaged so that the force required to pull out the suture is about 1 pound.  
  The swaged needle-suture combinations are prestressed in a Table Model INSTRON Tensile Tester as described in Example 1 above until the tension drops to 8 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the INSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the 10 sutures is recorded below:  
 6% ounces 6 ounces 9 ounces 7% ounces 8 ounces 9 ounces 6 ounces 7 ounces 6% ounces 6 ounces EXAMPLE 7 Size 5/0 black braided silk suture strands are swaged to channel needles manufactured of 14 mil wire (channel engagement seven sixty-fourths inch). The needles are swaged so that the force required to pull out the suture is within the range of 7 to 15 ounces.  
  The swaged needle-suture combinations are prestressed in a Table Model lNSTRON Tensile Tester (Model TT-DL) using a Type G-0l-3 Tension Cell (full-scale range 50 pounds), and the machine is set so that full-scale deflection is obtained at 5 pounds. Two line contact jaws are used to secure the needled sutures in the INSTRON machine. The upper jaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 psi. air pressure. The INSTRON machine is operated at a cross-head speed of 0.1 inches per minute and a chart speed of 5 inches per minute until the tension drops to 4 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the INSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the 10 sutures is recorded below:  
 3.2 ounces 3.42 ounces 3.76 ounces 4.6l ounces 4.7l ounces 3.10 ounces 3.70 ounces 3.25 ounces 4.12 ounces 3.15 ounces EXAMPLE 8 Size 6/0 polyester suture strands are swaged to preclosed channel needles manufactured of 12 mil wire and having a suture engagement of seven sixty-fourths inches. The needles are swaged so that the force required to pull out the suture is within the range of 5 to 8 ounces.  
  The swaged needle-suture combinations are prestressed in a Table Model INSTRON Tensile Tester (Model TT-DL) using a Type G-0l-3 Tension Cell (full-scale range 50 pounds), and the machine is set so that full-scale deflection is obtained at pounds. Two line contact jaws are used to secure the needled sutures in the lNSTRON machine. The upper jaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 p.s.i. air pressure. The INSTRON machine is operated at a cross-head speed of 0.1 inches per minute and a chart speed of 5 inches per minute until the tension drops to 3 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the INSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the sutures is recorded below:  
 3.05 ounces 3.10 ounces 2.51 ounces 2.75 ounces 2.35 ounces 2.70 ounces 2.56 ounces 3.58 ounces 2.78 ounces 2.93 ounces EXAMPLE 9 Size 7/0 white virgin silk suture strands are swaged to preclosed channel needles manufactured of 8 mil wire (channel engagement 50 mils). The needles are swaged so that the force required to pull out the suture is within the range of 3 to 4 ounces.  
  The swaged needle-suture combinations are prestressed in a Table Model lNSTRON Tensile Tester (Model TT-DL) using a B Tension Cell and the associated upper jaw (red). The instrument is calibrated with a 100 gram weight on the B cell clamp to full-scale deflection on the X-l scale. Two line contact jaws are used to secure the needled sutures in the lNSTRON machine. The upper jaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 p.s.i. air pressure. The lNSTRON machine is operated at a cross-head speed of 0.1 inches per minute and a chart speed of 5 inches per minute until the tension drops to 1.8 ounces.  
  Ten prestressed needle-suture combinations ran domly selected from this production batch are replaced in the lNSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the 10 sutures is recorded below:  
 1.73 ounces 1.53 ounces 1.46 ounces 1.60 ounces 1.28 ounces 1.98 ounces 1.40 ounces 1.39 ounces 1.82 ounces 1.77 ounces EXAMPLE 10 Size 8/0 white virgin silk suture strands are swaged to preclosed channel needles manufactured of 8 mil wire (channel engagement 50 mils). The needles are swaged so that the force required to pull out the suture is within the range of 2 to 3 ounces.  
  The swaged needle-suture combinations are prestressed in a Table Model INSTRON Tensile Tester (Model TT-DL) using a Type B Tension Cell and the associated upper jaw (red). The instrument is calibrated with a 100 gram weight on the B cell clamp to full-scale deflection on the X-l scale. Two line contact jaws are used to secure the needled sutures in the [N- STRON machine. The upper jaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 p.s.i. air pressure. The INSTRON machine is operated at a crosshead speed of 0.1 inches per minute and a chart speed of 5 inches per minute until the tension drops to 1.3  
 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the lNSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the 10 sutures is recorded below:  
 1.08 ounces 1.45 ounces 1.04 ounces 1 18 ounces 1.24 ounces 1.1 1 ounces 1.27 ounces 1 29 ounces 1.13 ounces 1.31 ounces EXAMPLE 1 1 Size 2/0 black braided silk suture strands are swaged to channel needles manufactured of 26 mil wire (channel engagement eleven sixty-fourths inch). The suture ends are inserted into the needles until they are in contact with the bottom of the drilled hole as shown in FIG. 3. The needles are then swaged so that the force required to pull out the suture is within the range of about from 2 to 4 pounds.  
  The swaged needle-suture combinations are prestressed in a Table Model lNSTRON Tensile Tester (Model TT-DL) using a Type CT Tension Cell (fullscale range pounds), and the machine is set so that full-scale deflection is obtained at 20 pounds. Two line contact jaws are used to secure the needled sutures in the INSTRON machine. The upper jaw grips the needle and the lower jaw grips the suture about 0.25 inches below the needle. Both jaws are closed under 20 p.s.i. air pressure. The lNSTRON machine is operated at a cross-head speed of 0.1 inches per minute and a chart speed of 5 inches per minute until the stress drops to 14 ounces.  
  Ten prestressed needle-suture combinations randomly selected from this production batch are replaced in the lNSTRON machine and stressed to pull the suture out of the needle. The pull-out value for each of the 10 sutures is recorded below:  
  8 ounces 1 1 ounces 16 ounces 13 ounces 9 ounces 13 ounces 10% ounces 12 ounces 1 1 ounces 14 ounces The needle-suture combinations of the present invention may be used by the surgeon employing conven tional suturing technique as illustrated in FIG. 1. After the suture has been placed, the needle may be separated by a wrist motion snapping the needle off the end of the suture as best illustrated in FIG. 2. The force required to pull the needle from the end of the suture is related to the suture size and is in the range of from about 1 ounce to about 26 ounces.  
 What is claimed is:  
  1. [n a method of manufacturing a swaged needle suture combination comprising a needle having pointed and blunt ends, said needle having an opening in the blunt end thereof and a suture, one end of which is received within said opening, the improvement comprising pre-stressing the suture with respect to said needle by applying sufiicient tension to the suture to move it relative to said needle; and releasing the tension when the force drops to a value within the following range for 2. A swaged needle-suture combination comprising a needle having pointed and blunt ends, said needle having an opening in the blunt end thereof and a suture, one end of which is received within said opening said suture being pre-stressed with respect to said needle so that the suture is displaced from the inner end of said opening whereby the suture may be pulled out of the needle by a force that is within the following range for that size of suture Suture Size Ounces 8/0 l. 2. 7/0 l. 3. 6/0 2. 5. /0 3. 7. 4/0 3. l5. 3/0 3. 23. 2/0 3. 26. H0 l0. 26.  
  l 10. 26. 2 and larger 10. 26.  
  3. The needle-suture combination of claim 2, wherein the suture is displaced from the inner end of the opening a distance of about 0.08 inches.  
  4. The needle-suture combination of claim 2, wherein the suture is displaced from the inner end of the opening a distance of about 42 to 50 per cent of the length of said opening.  
  5. The needle-suture combination of claim 2, wherein the needle is a drilled needle.  
  6. The needle-suture combination of claim 2, wherein the needle is a channel needle.  
  7. The needle-suture combination of claim 2, wherein the suture is a covered silk suture.  
  8. The needle-suture combination of claim 2, wherein the suture is a braided polyester suture.  
  9. The needle-suture combination of claim 8, wherein said polyester is polyhydroxyacetic ester.  
  10. The needle-suture combination of claim 8, wherein said polyester is a copolymer of glycolide and L(-) lactide.  
  11. The needle-suture combination of claim 2, wherein the suture is a braided nylon suture.  
  12. The needle-suture combination of claim 2, wherein the suture is a braided suture.  
  13. The needle-suture combination of claim 2, wherein the suture is a braided silk suture.  
  14. The needle-suture combination of claim 2, wherein the suture is a monofilament.  
  15. The needle&#39;suture combination of claim 2, wherein the needle is a curved needle.  
  16. The I needle-suture combination of claim 2, wherein the needle is a straight needle.  
  17. The needle-suture combination of claim 2, wherein the needle is a cutting edge needle.  
 18. The needle-suture combination of claim 2,  
 wherein the needle is a taper point needle.  
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