Knot-tying Technique Research Articles

Arthroscopic knot tying principles and instruments

Orthopedic surgeons must be proficient with many arthroscopic procedures. At the most basic level, consistent and secure tissue repair with arthroscopic knots is an essential skill. This skill can be mastered by following basic principles, practice, and attention to detail. There are special instruments to aid the surgeon in knot tying, knot tensioning, and suture cutting. A variety of suture material and knot designs is available and should be chosen to match the specific situation at hand. We do not intend to provide step-by-step instructions for tying every knot that has been described in the literature. Our goal is to provide a comprehensive overview of the arthroscopic knot-tying technique and the equipment available to today’s orthopedic surgeon. Knowledge of fundamentals will enable the surgeon to choose the appropriate suture material and knot construct, but practice is required to actually perform the task and know which instruments function best in their hands.

Rotator cuff repair with ultrasonic suture welding (SS-46)

Rotator cuff repair techniques traditionally employ suture fixation of the tendon to both soft and bony tissues. The suture is tied by hand or arthroscopic knot pusher to provide secure loops to fix tissue to facilitate healing. A new technology allows the creation of secure loops with ultrasonic energy welding. This study was conducted to assess the clinical results of mini-open rotator cuff repair employing ultrasonic suture welding. Fifty consecutive patients treated by one surgeon were retrospectively evaluated with an average follow-up of 26 months. These patients were then compared to 55 patients treated by the same surgeon with a technique employing standard knot-tying with nonabsorbable suture with similar follow-up. The groups were similar in regard to age, sex, hand dominance and preoperative duration of symptoms. All procedures were performed in a hospital ambulatory surgery center in a lateral decubitus position. A glenohumeral arthroscopy and arthroscopic acromioplasty were performed in all cases. All patients were evaluated by an independent examiner using the UCLA scale; 47 of the 50 suture weld patients were available for evaluation. Preoperative UCLA score averaged 21.5 and postoperative 29.8. There were four failures in this group but two of the patients who failed had a significant postoperative traumatic events; a dislocation in one and a car accident in another. Both patients underwent revision cuff repair. At revision. both repairs had pulled through tendon without failure of the weld. 40 of the 55 patients treated with tied sutures were available for evaluation. Preoperative UCLA score averaged 13.2 and postoperative 31.6. There was one failure in this group of patients and none with postoperative trauma. Postoperative scores for the two groups did not differ significantly according to Student t test. An Analysis of Covariance (ANCOVA) of postoperative UCLA scores was also not statistically significant. Suture welding produces secure loops that allow for cuff repair with results similar to traditional knot-tying techniques. Welding technology may facilitate arthroscopic cuff repair by obviating the need to tie arthroscopic knots.

Arthroscopic knot-tying techniques

The techniques of arthroscopic knot-tying have been introduced and refined over the last decade for the purpose of providing orthopaedic surgeons with a reliable means of securing arthroscopic capsular, labral, and tendon repairs within the shoulder. Arthroscopic knots can be broadly characterized as either sliding or nonsliding knots. Although many surgeons prefer sliding knots for their ease of use, the ability to tie nonsliding knots should also be mastered, as each type of knot has specific advantages and disadvantages when used for shoulder repair surgery. Understanding the principals of arthroscopic knot-tying and learning to tie secure knots with knot pushers, is essential for surgeons who intend to treat their patients' shoulder injuries using minimally invasive, arthroscopic repair techniques. Several fundamental considerations important to successful knot-tying are discussed within this article followed by a presentation of the steps required to tie several different arthroscopic knots.

Laparoscopic Ureterocalicostomy: A Feasibility Study

Ureterocalicostomy is occasionally indicated for reconstruction of recurrent, recalcitrant ureteropelvic junction obstruction associated with postoperative fibrosis and a relatively inaccessible renal pelvis. We investigated the feasibility of performing laparoscopic ureterocalicostomy in a survival porcine model. Anatomical, histological and chronic functional outcomes were evaluated. Laparoscopic ureterocalicostomy was performed in 10 survival female swine. A ureteropelvic junction obstruction model was created by laparoscopic ligation of a 2 to 3 cm. segment of upper ureter. After an interval of complete ureteropelvic junction obstruction laparoscopic ureterocalicostomy was performed in a manner duplicating the steps of conventional open surgery. After transverse amputation of the lower renal pole end-to-end anastomosis of the proximal ureter to the inferior calix was formed by laparoscopic freehand suturing and knot-tying techniques. Mean ureter stricture length was 2.2 cm. (range 1.7 to 3.1). Mean duration of obstruction before laparoscopic ureterocalicostomy was 6.3 days (range 2 to 18). Mean operative time for laparoscopic ureterocalicostomy was 165.3 minutes (range 105 to 240). Mean estimated blood loss was 145 cc (range 25 to 400). Mean stent duration in 6 pigs was 8.7 days (range 7 to 11). Excretory urograms demonstrated immediate function with symmetrical and unobstructed drainage in all operated renal units. At 4 to 8 weeks of followup no urine leaks were noted and histological examination documented complete urothelial healing without fibrosis or scar formation. Laparoscopic ureterocalicostomy is technically feasible in the porcine model and it effectively duplicates the established principles of open surgery. Our technique further extends the application of laparoscopic surgery for difficult ureteropelvic junction obstruction.

A reusable suture anchor for arthroscopy psychomotor skills training

For residents to adequately develop the early arthroscopy psychomotor skills required to better learn how to manage the improvisational situations they will encounter during actual patient cases, they need to experience sufficient practice repetitions within a contextually relevant environment. Unfortunately, the cost of suture anchors can be a practice repetition–limiting factor in learning arthroscopic knot-tying techniques. We describe a technique for creating inexpensive reusable suture anchors and provide an example of their application to repair the anterior glenoid labrum during an arthroscopy psychomotor skills laboratory training session.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 19, No 3 (March), 2003: pp E20

Microsurgical training with surgical gauze: the first step.

To assist nascent microsurgeons in the initial practices of handling instruments and tying knots before using an animal model, the authors discuss surgical gauze, which will be of benefit to all trainees. In this model, the nascent microsurgeon can familiarize himself or herself with the operating microscope, correct handling of microinstruments, and the technique of knot tying. Surgical gauze is readily available in the operating room, and there is no need to seek out experimental or animal laboratories, or to obtain poultry or placenta before proceeding to animal models.

Ergonomic Analysis of Laparoscopic Knot Tying

The laparoscopic knot-tying technique of novice and expert surgeons was analyzed to determine the ergonomics of both groups. Data capture was via an established virtual reality system, which includes a human force and torque feature. Novices had on average a lower angle of shoulder abduction than experts (25.64 degrees compared with 29.57 degrees) and a wider standard deviation than experts (5.41 compared with 4.46). Average time to completion of the task (three knots) was 433 seconds for novices against 310 seconds for experts. The mean torque magnitude did not simply increase with the angle of abduction. The angle at which torque was minimal for the shoulder was 27 degrees, and for the level of the third and fourth thoracic vertebrae, it was 22 degrees.

Endoscopic Suturing and Knot Tying: Theory Into Practice

To advance modern surgical techniques of endoscopic knot tying, encompassing a new appreciation of knot-tying theory and the application of second-generation, purpose-designed instruments. During open surgery, surgeons automatically create the surgical half-hitch by using either instrument or hand/finger knot-tying methods (figure 4). Each of these methods, which are mirror images of each other, forms the same result, the half-hitch. Two opposing half-hitches are needed to form a square knot. There are many ways for new-generation instruments to create a secure square knot during endoscopic surgery. An overview of the current endoscopic knot-tying methods is presented. The author presents a theoretical analysis of square knot-tying techniques as applied during instrument and hand/finger movements. The application of a mirror-image concept was considered in the analysis of these two contrasting methods. There are 12 ways to create a square knot, some of which have previously not been described or needed in open surgery. Some of these methods have particular application in endoscopic surgery. A new understanding of knot-tying theory has been developed, with innovative methods being defined for tissue approximation during endoscopic surgery. These ergonomic, efficient, and contrasting methods of knot tying are described using second-generation endoscopic instruments. The new techniques have direct and broad application in many fields of minimally invasive surgery.

THE PRE-LOOPED INTRACORPOREAL KNOT: A NEW TECHNIQUE FOR KNOT TYING IN LAPAROSCOPIC SURGERY

Intracorporeal knot tying in laparoscopic surgery is time-consuming and difficult to learn. We present a new technique, that we call the pre-looped intracorporeal knot technique, which obviates the difficulties and saves time. We devised a homemade suture ring that allows the introduction of the suture thread wrapped on the needle driver and ready for knot tying simply by pulling on both extremities of the thread. Our experience with this technique proved it to be easy to apply and to learn. The prelooped intracorporeal knot technique allies the sophistication of intracorporeal knot tying to the easiness and simplicity of the extracorporeal classic suturing. It renders intracorporeal knotting an easy and rapid task to achieve.

Laparoscopic renal autotransplantation.

Renal autotransplantation is an extensive open surgical operation consisting of two distinct procedures, live-donor nephrectomy and autotransplantation, and requiring two large skin incisions. Herein, we analyze the feasibility of performing the entire procedure laparoscopically. Renal autotransplantation was performed entirely laparoscopically in six female farm pigs. Following a left donor nephrectomy, intracorporeal renal hypothermia was achieved by intra-arterial perfusion of ice-cold solution through a 4F balloon catheter. During autotransplantation, the renal vessels were anastomosed intracorporeally to the previously prepared ipsilateral common iliac vessels in an end-to-side fashion. Laparoscopic freehand suturing (5-0 Prolene) and knot-tying techniques were employed exclusively. A staged contralateral native nephrectomy was performed in five animals. Postoperative follow-up included serial creatinine measurements, intravenous urography, aortography, and renal histologic examination. The mean operating time was 6.2 hours (range 5.3-7.9 hours), the venous anastomosis time was 33 minutes (range 22-46 minutes), the arterial anastomosis time was 31 minutes (range 27-35 minutes), and the total iliac clamping time was 77 minutes (range 62-88 minutes). The total renal ischemia time was 68.7 minutes: warm ischemia 5.1 minutes, cold ischemia 33 minutes and rewarming 31 minutes. Serum creatinine concentrations remained stable: baseline 1.3 mg/dL, after autotransplantation 1.1 mg/dL, and after contralateral nephrectomy 1.6 mg/dL. Intravenous urography and aortography prior to euthanasia (N = 5) demonstrated prompt contrast uptake and excretion by the autotransplanted kidneys and patent arterial anastomoses, respectively. Histopathologic examination of the autograft demonstrated normal renal architecture. Renal autotransplantation can be performed utilizing laparoscopic techniques exclusively. This study may form the basis for performance of complex urologic vascular procedures laparoscopically.

Laparoscopic suturing evaluation among surgical residents.

Laparoscopic suturing is an integral part of advanced laparoscopic surgery training. The objective of this study was to evaluate the performance and preference of surgical residents performing intracorporeal and extracorporeal knot-tying techniques using conventional and Endo Stitch instruments. The residents were also evaluated on their suturing techniques using conventional instruments, the Endo Stitch, and the Suture Assistant. Using an inanimate laparoscopic trainer model, 39 residents were evaluated as they performed laparoscopic knot tying exercises. Endpoints of the study were execution time and subjective preference of surgical residents with respect to the type of instrument used for knot tying. Forty-three residents were evaluated as they performed laparoscopic suturing exercises with three different types of suturing instruments using the same endpoints. The intracorporeal technique was the preferred (89%) method of knot tying among surgical residents. The time for completion of laparoscopic suturing was significantly (P < 0.05) shorter with the Endo Stitch (114 +/- 64 s) than with the conventional instrument (206 +/- 107 s) or the Suture Assistant (151 +/- 70 s). Residents preferred the use of the Endo Stitch in all three categories for suturing, knot tying, and handling. The Endo Stitch enhanced laparoscopic skills and was the preferred instrument for laparoscopic knot tying and suturing among surgical residents.

Laparoscopic radical cystoprostatectomy with ileal conduit performed completely intracorporeally: the initial 2 cases

Objectives. To present the initial 2 patients who underwent laparoscopic radical cystoprostatectomy, bilateral pelvic lymphadenectomy, and ileal conduit urinary diversion, with the entire procedure performed exclusively by intracorporeal laparoscopic techniques. Methods. Two male patients, 78 and 70 years old, with muscle-invasive, organ-confined, transitional cell carcinoma of the urinary bladder underwent the procedure. The entire procedure, including radical cystoprostatectomy, pelvic node dissection, isolation of the ileal loop, restoration of bowel continuity with stapled side-to-side ileoileal anastomosis, retroperitoneal transfer of the left ureter to the right side, and bilateral stented ileoureteral anastomoses were all performed exclusively by intracorporeal laparoscopic techniques. Free-hand laparoscopic suturing and in situ knot-tying techniques were used exclusively. Results. The surgical time was 11.5 hours in the first patient and 10 hours in the second. The respective blood loss was 1200 mL and 1000 mL. In both patients, ambulation resumed on postoperative day 2, bowel sounds on day 3, and oral intake on day 4; the hospital stay was 6 days. Narcotic analgesia comprised 108.3 mg and 16.5 mg of morphine sulfate equivalent, respectively. Pathologic examination revealed pT4N0M0 (prostate) and pT2bN0M0 transitional cell carcinoma of the bladder with the surgical margins negative for cancer in both patients. No intraoperative or postoperative complications occurred in either patient. Conclusions. To our knowledge, this is the initial report of laparoscopic radical cystoprostatectomy with intracorporeal ileal conduit urinary diversion. We believe that with further experience and refinement in the operative technique, laparoscopic radical cystoprostatectomy with ileal conduit urinary diversion may become an attractive treatment option for selected candidates with localized muscle-invasive bladder cancer.

Robotic-assisted laparoscopic pyeloplasty: a pilot study

Objectives. Robotic technology has been employed to manipulate the laparoscope during urologic procedures. However, to our knowledge, robotic technology has not been previously applied to actually perform the urologic laparoscopic procedure. The objective of this study was to determine the feasibility and efficacy of performing robotic-assisted laparoscopic pyeloplasty and compare it with conventional laparoscopic pyeloplasty in an acute porcine model. Methods. Five female swine (10 kidneys) were prospectively randomized to undergo unstented robotic-assisted laparoscopic pyeloplasty (6 kidneys) or conventional laparoscopic pyeloplasty (4 kidneys). Robotic pyeloplasty was performed with the Zeus robotic system, which incorporates three remote-controlled interactive arms: one voice-activated arm to control the laparoscope and two robotic arms to manipulate purpose-designed instruments. Tissue dissection and transection of ureteropelvic junction area were performed manually by conventional laparoscopy. The pyeloureteric anastomosis during the robotic-assisted pyeloplasty was performed completely robotically from a remote workstation using running 5-0 absorbable sutures. Conventional laparoscopic pyeloplasty was performed manually by laparoscopic intracorporeal suturing and knot-tying techniques. Immediate patency and anastomotic integrity were evaluated by intravenous indigo carmine and ex vivo retrograde ureteropyelogram. Results. In comparing robotic and conventional laparoscopic pyeloplasty, the following data were obtained: total surgical time (115.2 versus 94.5 minutes, P = 0.2), anastomosis time (75.7 versus 64.3 minutes, P = 0.3), and total number of suture-bites per ureter (13.0 versus 12.5, P = 0.8). Anastomoses were immediately watertight in 5 of 6 robotic and 3 of 4 conventional pyeloplasties. Conclusions. Robotic-assisted laparoscopic pyeloplasty is a feasible and effective procedure that may enhance surgical dexterity and precision. This has implications for clinical applications of laparoscopic telesurgery in the future.

A Method for Learning Surgical Knot-Tying Technique in a General Medicine Training Program

A Method for Learning Surgical Knot-Tying Technique in a General Medicine Training Program

Endoscopic knot tying made easier.

A new laparoscopic instrument has been developed to facilitate intracorporeal suturing and knot tying. The instrument combines both needle-holding jaws and a loop-forming member. The handle is ergonomically designed and contains a locking mechanism. This simple technique of knot tying extends the role of instrument rotation and contrasts out all other known methods of knot tying.

A PORTABLE TENSIOMETER FOR ASSESSING KNOT-TYING TECHNIQUE

The purpose of this study was to determine the influence of orthopedic surgeons' tying techniques on knot security using 2-0 and 4-0 monofilament and multifilament nylon sutures. Using an Instron Tensile Tester and a portable tensiometer, knot security was achieved with these sutures using four-throw square knots (1 = 1 = 1 = 1). After didactic and psychomotor skill training, medical students were taught to construct the four-throw square knot using either a two-hand tie or an instrument tie. Using the portable tensiometer, their knot-tying techniques were judged to be superior to those used by orthopedic surgeons. The orthopedic surgeon's faculty technique can easily be corrected by didactic information and psychomotor skill training.

Effect of suture material on postoperative astigmatism

Two hundred patients were enrolled in a randomized, prospective clinical trial comparing the use of 10-0 nylon, 10-0 polypropylene (Prolene®), 11-0 polyester (Mersilene®), and 10-0 polyethylene (Novafil®) suture materials on the amount and decay curves of surgically induced astigmatism following intraocular lens (IOL) surgery. Patients with Mersilene and nylon sutures had the highest amounts of induced with-the-rule (WTR) cylinder (significantly more than Prolene) at one day after surgery. However, the WTR cylinder decayed rapidly for nylon during the first three months but more slowly for Mersilene because of its lack of stretchability. The Prolene group had the lowest level of induced WTR cylinder at one day, but against-the-rule (ATR) drift occurred, leaving cases with ATR astigmatism by a year. The nylon group had the second highest amount of induced WTR cylinder at one day, which had decayed to ATR cylinder by five months. Between one and two years postoperatively, the nylon group experienced a significant ATR shift. The amount of early induced WTR cylinder seemed to be related to the knot-tying technique and tissue gripping characteristics, whereas the shape of the decay curve was related to the material characteristics of the suture.

Arthroscopic stabilization: Suture technique

A new arthroscopic suture technique to repair the Bankart lesion using an intra-articular knot-tying technique is described. Fifteen patients with unidirectional posttraumatic anterior instability of the shoulder have undergone arthroscopic suture repair with a 93% success rate. Intra-articular suture repair promises to be a positive step in the development of arthroscopic techniques for the treatment of shoulder instabilities.

Arthroscopic Bankart repair using suture anchors

Arthroscopic Bankart procedures have been well described, and their results have produced a significant improvement over those of other arthroscopic capsulorraphy techniques. Nonetheless, objections to these arthroscopic Bankart techniques persist. The primary objections are the drilling of transscapular pins out the posterior scapular neck in proximity to the suprascapular nerve and the tying of sutures over the muscle belly and fascia of the infraspinatus. The arthroscopic Bankart procedure using suture anchors nullifies these objections by the fixation of sutures, placed in the detached ligament labral complex, directly to the anterior glenoid rim without transscapular drilling. The procedure was performed in 14 patients with anterior inferior instability. The instability was conformed by examination under anesthesia, and the intra-articular pathology was evaluated arthroscopically. Two or three sutures and anchors were used to reattach and retension the inferior glenohumeral ligament labral complex. The procedure requires the use of two anterior portals and intra-articular knot-tying techniques. Although the follow-up is short, there have been no complications and no recurrences of the symptoms of instability. This new approach offers distinct advantages over existing arthroscopic Bankart techniques without altering the basic principles of the procedure. Suture anchors, intially designed to facilitate traditional open Bankart procedures, can also be used arthroscopically, thus avoiding transscapular drilling and risk to posterior structures.

Knot security of synthetic absorbable suture material; a comparison of polyglycolic acid and polyglactin-910

To compare the knot reliabilities of two kinds of synthetic absorbable suture material, twelve different knots commonly used in surgical practice were tested. Twenty tests were performed on each knot, i.e., ten with Dexon-S ® (uncoated) and ten with Vicryl ® (coated). The knots made with Dexon-S ® were found to slip less frequently, to be significantly stronger, more consistent, and more reproducible than those made with Vicryl ®. It was concluded that uncoated Dexon-S ® is superior to coated Vicryl ® with respect to knot reliability. The practical implications of these findings for surgical performance are discussed. It is emphasized that surgeons should be more aware of the relationship of the holding power of surgical knots to not only the knot-tying technique but also the kind of suture material used.