Knot security in simple sliding knots and its relationship to rotator cuff repair: how secure must the knot be?

We sought to determine which simple sliding knot configurations would have adequate strength for rotator cuff repair. Four knot configurations were tied with both No. 1 polydioxanone suture and No. 2 Ethibond suture (Ethicon, Somerville, NJ) using 3 different tying techniques: hand-tie, standard knot pusher, and cannulated double-diameter knot pusher. The knots were then tested to failure on a materials testing system. The weakest standard knot configuration was S=S=S=S. The other 3 knot configurations (S//S//S//S, SxSxSxS, and S//xS//xS//xS) generally failed in the 35 to 50 N range. Ultimate strength in this range can be shown to be adequate to withstand, without suture failure, a maximal contraction of a repaired rotator cuff tear within the rotator crescent, assuming certain conditions are met (suture anchors placed 1 cm apart, 2 sutures per anchor). More complex knots are not necessary for adequate knot security. However, the same configuration with only 1 suture per anchor will not be strong enough because the suture will fail under maximum physiological load. This study shows that we can predict the adequacy of a given knot configuration under maximum physiological loading conditions.

[1]  J A Sidles,et al.  Optimizing arthroscopic knots. , 1995, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[2]  C Gerber,et al.  Mechanical strength of repairs of the rotator cuff. , 1994, The Journal of bone and joint surgery. British volume.

[3]  D. Holmlund STANDARDIZED ELECTROCARDIOGRAPHY IN DOG WITH A VIEW TO EVALUATION OF LOCAL MYOCARDIAL ISCHEMIA , 1974 .

[4]  M. Wirth,et al.  Cyclic loading of transosseous rotator cuff repairs: tension overload as a possible cause of failure. , 1997, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[5]  P. Gunderson The half-hitch knot: a rational alternative to the square knot. , 1987, American journal of surgery.

[6]  A. Peters,et al.  Mechanical knot performance of a new generation polydioxanon suture (PDS‐2) , 1991, Acta obstetricia et gynecologica Scandinavica.

[7]  D. T. Harryman,et al.  Optimizing arthroscopic knots using braided or monofilament suture. , 1998, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[8]  P. Klopper,et al.  Performance of sliding knots in monofilament and multifilament suture material , 1986, Obstetrics and gynecology.

[9]  R. W. Bassett,et al.  Glenohumeral muscle force and moment mechanics in a position of shoulder instability. , 1990, Journal of biomechanics.

[10]  J. Trimbos,et al.  Mechanical performance of square knots and sliding knots in surgery: comparative study. , 1990, American journal of obstetrics and gynecology.

[11]  S S Burkhart,et al.  Loop security as a determinant of tissue fixation security. , 1998, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[12]  D. de Haas,et al.  Dynamic loading of surgical knots. , 1991, Surgery, gynecology & obstetrics.

[13]  M. Wirth,et al.  Cyclic loading of anchor-based rotator cuff repairs: confirmation of the tension overload phenomenon and comparison of suture anchor fixation with transosseous fixation. , 1997, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[14]  R. Edlich,et al.  Mechanical performance of polyglycolic acid and polyglactin 910 synthetic absorbable sutures. , 1981, Surgery, gynecology & obstetrics.

[15]  S. Fischer,et al.  Tissue fixation security in transosseous rotator cuff repairs: a mechanical comparison of simple versus mattress sutures. , 1996, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[16]  S. Burkhart,et al.  The rotator crescent and rotator cable: an anatomic description of the shoulder's "suspension bridge". , 1993, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[17]  W D Cannon,et al.  Elongation of Arthroscopically Tied Knots , 1997, The American journal of sports medicine.

[18]  Herrmann Jb,et al.  Tensile strength and knot security of surgical suture materials. , 1971 .