Half Hitches Research Articles

Optimizing lead body control during lead extractions: the "Felix helix" lead compression method.

Figure 2 The twisted stylet is bent flush to the lead body, and the free lengths of the stylet are wrapped around the lead. The stylet arms are then twisted again perpendicular to the lead with a needle driver. A crucial factor in the success of a lead extraction is maintaining control of the lead body. Control of the lead can be obtained by using multiple tools. A lead locking stylet is usually placed down the pace-sense conductor of the lead to be extracted and secured. Spectranetics (Colorado Springs, CO) offers a line of lead locking devices, and Cook Medical (Bloomington, IN) offers the Liberator Beacon Tip Locking Stylet. When the lead locking device or stylet is retracted more forcibly relative to the outer components of the lead, there is an increased chance that the inner components will unravel and control of the lead may be lost. To keep the lead as one piece, the outer components of the lead need to be compressed onto the inner stylet. The outer body of the lead is usually secured with a long silk tie and half hitches may be tied to distribute the tension about the proximal portion of the lead. Cook Medical has developed the One-Tie lead compression coil that is akin to a paper clip that is wound around the lead locking stylet and half around the outer lead body. The purpose of this device is to compress the lead in a

Optimization of the Racking Hitch Knot: How Many Half Hitches and Which Suture Material Provide the Greatest Security?

Reliable methods of fixation of soft tissue and bone are of utmost importance in reconstructive shoulder surgery and in many orthopaedic applications. Current methods of securing lesser tuberosity osteotomies performed during shoulder arthroplasty and tuberosity fixation performed during repair of proximal humeral fractures often rely on alternating half hitches or surgeon's knots regardless of the suture configuration used passing through the tissue (eg, Mason-Allen, Krackow). The racking hitch knot in contrast to half hitches allows sequential tightening, even under tension, with minimal risk of knot slippage or premature locking. These knot characteristics allow the surgeon to stepwise improve their reduction before committing and locking a construct, preventing hanging knots or under-tensioned repairs. However, little data exist to support the use the racking hitch knot to guide decision making regarding how to back up the knot or to explain the effect of suture material on security and strength. The objectives of our study were (1) to identify the optimal number of half hitches necessary to maintain knot security for a single knot; (2) to evaluate if a difference exists in the relative behavior of racking hitch knots when tied using different suture materials; and (3) to define the biomechanical differences between the racking hitch and two other knot configurations commonly used in shoulder surgery (Weston and square knots). Using an Instron device we tested the effect of adding supplemental half hitches (from one to four) to the racking hitch. Additionally, a selection of commercially available braided nonabsorbable polyethylene sutures and different knot configurations (racking hitch, Weston knot, and square knot) also were tested. Data were compared using ANOVA. Increasing the number of half hitches improved knot performance in peak load testing and cyclic testing, revealing a significant difference between the racking hitch supplemented with one and four half hitches (199.2 N versus 428.8 N, p < 0.05). Force Fiber™ #2 (359.6 N) and FiberWire(®) #2 (302 N) showed increased loads to failure compared with Ethibond Excel™ #2 or Force Fiber™ #3/4, whereas Ethibond Excel™ had the least amount of slippage during cyclic testing (0.09 mm). The racking hitch knot had considerably higher loads to failure (359.6 N) than the Weston (145.2 N) or square (77 N) knots. The racking hitch knot exhibited significantly higher loads to failure and comparable knot slippage (elongation during cyclic testing) when compared with other commonly used knots. According to the biomechanical data, the addition of four half hitches to supplement the racking hitch and the choice of FiberWire(®) #2 or Force Fiber™ #2 suture resulted in increased knot security. This knot adds a tool to the arsenal for surgeons best suited for repairs requiring a high degree of knot security and reliable tissue tensioning.

Tying Arthroscopic Knot for Glenoid Suture Anchor

As arthroscopic and minimally invasive procedures have become increasingly more common over the past decade, a versatile understanding of several arthroscopic knot tying techniques is essential for reproducible and reliable repairs. While there are numerous descriptions of unique arthroscopic knots, selection and correct implementation is critical for adequate soft tissue fixation and successful patient outcomes. Specifically, the Roeder knot, a type of locking sliding knot, with 3 alternating half hitches, has been described to provide the loop and knot security among other sliding knot techniques. Therefore, the Roeder knot has emerged as a preferred knot tying technique amongst orthopedic surgeons, especially in the setting of arthroscopic shoulder stabilization procedures. In this case, we describe the basic fundamentals of performing a Roeder knot with 3 alternating half hitches to anchor the labrum to the glenoid in the setting of an arthroscopic Bankart repair.

Systematic instruction of arthroscopic knot tying with the ArK Trainer: an objective evaluation tool

A Proficiency Formula was introduced as an objective self-evaluation method for evaluating basic arthroscopic knot tying in a laboratory setting. The correlation between the Proficiency Formula and gold standard pass/fail dichotomy was demonstrated, as well as with other popular evaluation tools--task-specific checklist (TSC) and global rating scale (GRS). A step-by-step video tutorial was used to instruct 35 medical students on how to tie an arthroscopic Samsung Medical Center (SMC) knot secured by three half hitches. Participants were video recorded performing arthroscopic knot tying and assessed on their success tying an SMC knot, pass or fail, and through three outcome tools: the Proficiency Formula, GRS and the TSC. Independent samples t test was used to compare the GRS, TSC and Proficiency Formula scores, between those who were passed or failed by the evaluators. Correlation between the measurement scales was tested using Spearman's rho correlation coefficient. Participants received a mean proficiency score of 195 (140-249). The mean Proficiency score for those that passed was 323 (95 % CI 272-374), for those that failed, 87 (95 % CI 26-148, p < 0.001). We found strong linear correlation between the Proficiency Formula and GRS and TSE (0.83 and 0.78, respectively). The Proficiency Formula has high correlation with gold standard GRS and TSC measurements when used to assess arthroscopic knot tying skills on a model. It has the added advantage of being able to be self-assessed.

Paper 144: Arthroscopic Sliding Knot: How Many Additional Half Hitches Are Really Needed?

Paper 144: Arthroscopic Sliding Knot: How Many Additional Half Hitches Are Really Needed?

Running sutures anchored with square knots are unreliable

BackgroundA previous study showed that running polypropylene sutures anchored with square knots retain only 75% of their strength compared with half hitches. The aim of this study was to investigate whether anchor knot geometry similarly affects the tensile strength of other types of sutures used in continuous closures. MethodsMonofilament and multifilament sutures (all 3-0) were anchored with either square knots or half hitches to 1 tensionometer post, and the running ends were secured to the other. The force required to break the running suture and the site of suture failure were recorded. ResultsThe running sutures anchored with square knots retained only 50% to 84% of the strength of the identical sutures secured with half hitches (P < .001). ConclusionsA running suture anchored with half hitches is stronger and safer in comparison with the same suture anchored with square knots. This study provokes a fundamental reconsideration of the use of square knots to anchor running sutures.

An analysis of more than 100 cases involving knots and ligatures: knot frequencies, consistent tying habits and noteworthy outliers

Knot data from 114 cases were tabulated. Some of the evidence had been lost, or was of such low quality that no knot identification or analysis could be made, thus highlighting the need for careful preservation at the scene. Only 3–6% of exhibit tiers produced sophisticated knots, and these individuals were consistent in the chirality of such formations as Bowlines and Sheet Bends. Most tiers produced simple, basic Half Knots, Half Hitches, Granny Knots, Reef Knots, Overhand Loops and Slip Loops. Tiers demonstrated repeatable tying patterns, weakly or strongly favouring one chiral enantiomer over the other. The S enantiomer occurred more frequently in the case evidence presented. Some tiers reversed the chirality of an initial or terminal knot in an otherwise consistent string of Half Hitches or Half Knots. Contextual clues provided by the types of knots – in addition to their capsizement, location and function – indicated whether one or two wends were employed in the tying. Ubiquitous tying materials were noted. These included items of utility and availability found at the scene, such as clothing and cable as well as rope and cord. The reported observations support previous research and can guide future analyses of knotted evidence.

Intermediate and Early Rupture of Expanded Polytetrafluoroethylene Neochordae After Mitral Valve Repair

Neochordae construction using an expanded polytetrafluoroethylene suture is an accepted surgical technique to correct mitral regurgitation due to mitral valve prolapse. We report two cases of intermediate and early rupture of CV-5 expanded polytetrafluoroethylene neochordae after mitral valve repair. As a result of these cases, we now use CV-3 expanded polytetrafluoroethylene for neochordae construction with no failures.

Cyclic Load and Failure Behavior of Arthroscopic Knots and High Strength Sutures

To compare the biomechanical performance of several different sutures by evaluating knot security and load to failure strength using different arthroscopic knots. Eight different No. 2 sutures (Ethibond [Ethicon, Somerville, NJ], FiberWire [Arthrex, Naples, FL], Orthocord [DePuy-Mitek, Norwood, MA], Hi-Fi [ConMed Linvatec, Largo, FL], Ultrabraid [Smith & Nephew, Andover, MA], ForceFiber [Stryker Endoscopy, San Jose, CA], MagnumWire [ArthroCare, Sunnyvale, CA], and MaxBraid PE [Arthrotek, Warsaw, IN]) were tied arthroscopically into standardized loops using 6 different knots (Weston, Tennessee slider, Duncan, SMC, Revo, and San Diego knot) 10 times each. The suture loops were pretensioned to 10N, cycled between 10N and 45N for 1,000 cycles, and loaded to failure. The failure load for each suture, each knot, and slippage trend during cyclic loading was recorded. The Revo and SMC knots (group A) were stronger than the Tennessee and San Diego knots (group B), which were stronger than the Weston knot, which was stronger than the Duncan loop (P < .05). This pattern also coincided with the loads at which these knots slipped. Evaluating the sutures showed that Ethibond had lower failure loads than all other sutures and FiberWire showed statistically higher loads (P < .05). Duncan loops (97.5%) and Weston knots (86.3%) slipped more than other knots (P < .001), while the SMC and Revo knots slipped least. Ethibond sutures were least likely to slip. The Duncan loop and Weston knot were more likely to slip than all other knots, and caution should be exercised when tying them with high-strength sutures. The Revo, Tennessee slider, San Diego, and SMC knots were least likely to slip (P < .001). While stronger than braided polyester sutures, newer sutures containing ultra-high molecular weight polyethylene have a greater tendency to slip. Backing up knots with 4 reversed half hitches with switched posts does not guarantee knot security.

On the Origin and Evolution of the Roeder Knot and Loop—A Geometrical Review

The first laparoscopic sliding knot to be described was the Roeder knot; it has been used for a variety of procedures in all surgical disciplines. It was surmised that the introduction of new modifications in the geometry of the knot paralleled the introduction of its new indications, and that not all modifications improved its security. Therefore, a geometrical review was made of all modifications and all data on knot security and loop security of the knot were analyzed. The introduction of the original knot and its 14 applicable modifications paralleled the increase in minimally invasive techniques and the spread of these techniques in all the medical specialties. Roeder loop security depends predominantly on the number of initial turns around the standing part. Its knot security depends on the additional half hitches used to backup the knot after it has been tightened. Only a few of the modifications improved the security of the knot or its previous modifications.

Square Not a Running Knot

The tensile strength of running monofilament polypropylene sutures anchored with square knots was compared with the strength of the same size sutures anchored with half hitches. Polypropylene (Prolene; Ethicon) 0, 2-0, 3-0, 4-0, and 5-0 sutures were secured to a tensionometer with either square knots or half hitches. As tension was applied to the running suture end, the force required to break the suture and the point at which the break occurred were recorded. The sutures anchored with square knots showed only 75% of the strength of the sutures secured with half hitches (p=<0.001). Every suture tied with square knots broke precisely at the point where the last two squared throws invariably tumbled into half hitches with increased tension on the running end. The resulting stress transformation distorted and weakened the suture, as documented by electron microscopy scanning. The sutures secured with half hitches did not show any surface defects, and none of the running sutures tied down with half hitches broke at the knots. A running polypropylene suture initially anchored with half hitches is stronger and safer than a running suture tied down with square knots.

The Arthroscopic Square Knot: A Biomechanical Comparison With Open and Arthroscopic Knots

To compare the loop and knot security of arthroscopic square knots with other arthroscopic and open knots with the use of 2 commonly used suture types. Five knot configurations were tested 12 times each. The arthroscopic square knot was compared with the open square knot, arthroscopic and open half hitches with alternating posts, and the Duncan loop. Load-to-failure testing was performed at a rate of 1.25 mm/sec, and cyclic testing was performed between 7 N and 30 N at a rate of 1 N/sec for 50 cycles. Two suture types were tested: No. 2 Ethibond suture and No. 2 FiberWire. Among the No. 2 Ethibond sutures, the arthroscopic Duncan loop had the highest load-to-failure at 165 N. The remaining knot types failed at between 142 N and 148 N. The load at 3 mm of lengthening was between 100 N and 120 N for all knots. The No. 2 FiberWire failed at higher loads than the No. 2 Ethibond suture for all knot types except the Duncan loop. The arthroscopic half hitches, arthroscopic square knots, and open half hitches all failed at between 220 N and 264 N. The open square knot failed at 188 N, and the Duncan loop failed at 147 N. The load at 3 mm of lengthening was between 130 N and 165 N for all knots except the Duncan loop, which failed at 95 N. With cyclic testing, arthroscopic square knots performed better than all knot types, but the differences were clinically insignificant. Arthroscopic square knots have the same or greater strength when compared with other arthroscopic or open knots tied with the same suture type, and they perform as well or better in the face of cyclic loads. Good knot security can be attained with all of the knots tested, regardless of suture type. Equivalent knots tied with No. 2 FiberWire fail at higher loads, except for those tied with the Duncan loop. Arthroscopic square knots can be used in the clinical setting with no compromise in function when compared with open square knots.

Arthroscopic outside-in meniscal repair through a needle hole.

This article describes an alternative method for outside-in repair of a longitudinal meniscal tear through a needle hole, which will produce an almost negligible cutaneous scar. The procedure is performed under arthroscopic set-up using an 18-gauge needle preloaded with appropriate suture material. Insert the needle twice through the same cutaneous entry hole to form a mattress loop across the torn meniscal segments. The first insertion penetrates both segments and forms a loop. The second insertion then engages the outer segment and forms another loop. Draw the free end of this second loop into the joint and feed it into the first loop. Pull the first loop out from the joint together with the trapped portion near the free end, until the whole suture becomes a vertical mattress. Finally, tie a slipknot and several half hitches to close the meniscal gap under the stitch. In a large bucket-handle tear, stitches should be started at the middle and then alternating anteriorly and posteriorly 3 to 4 mm apart. To ensure that no significant extracapsular structures are trapped in each stitch, a 13-gauge needle can be used as a cannula sheath. This technique is economical and technically safe and simple for reparable meniscal lesions, including the posterior horn.

Transoral Endoscopic Obesity Surgery: Endoscopic Gastroplasty with an Endoluminal Endoscopic Suture Device

Operations to decrease the capacity of the stomach is a well-established option for the treatment of morbid obesity. It can be performed by means of either an open technique or a laparoscopic approach. Endoscopic transoral gastroplasty has obvious attractions as general anaesthesia can be avoided and the procedure is potentially reversible. We describe here our first experience of creating a gastric pouch using a newly designed suturing apparatus. A fresh porcine stomach was placed in Erlangen model with its esophagus connected to a long overtube. The suture device prototype, designed and manufactured by the Apollo Group and Olympus Company, contains a curved needle with a detachable tip. After puncturing the tissue to be sutured, the tip of needle is engaged in a cartridge and an intracorporeal ligation then made. A long 3-0 Nylon thread was first introduced into the stomach with the two ends outside. The suturing device, pre-mounted outside a standard gastroscope was inserted into stomach through the overtube. Several stitches were made, attaching the Nylon thread to both anterior and posterior walls of the stomach along the line for the stomach to be partitioned. When all the sutures were placed, five-throw of half hitches were tied on the Nylon thread extracorporeally and separately pushed into place using a knot pushing cap attached to another endoscope. The thread was then cut with an endo-scissors. Endoscopic and open inspection showed that the cartridges were brought together, successfully creating a small pouch. In conclusion, it is technically possible to accomplish a small stomach pouch with the endoscopic suture device in a simulated animal model. The suturing device and technique needs further refinement to improve the ease of operation. Animal studies are required to prove efficacy before clinical application. (The Apollo Group: SC Sydney Chung, Peter B Cotton, Christopher J Gostout, Robert H Hawes, Anthony N Kalloo, Sergey V Kantsevoy, Pankaj J Pasricha)

3472 Endoscopic mucosal resection for flat, wide-based gastric tumors with sutured wound closure.

Background: Submucosal [SM] resection allows small mucosal or SM tumors to be removed from stomach, esophagus and colon at modest risk of perforation. The availability of a method to oversew a perforation with endoscopic sewing machine [ESM} subsequent to SM resection might make this method safer. Methods: Bands were applied to gastric tissue using a band ligating device and the resulting polyp was resected using coagulative diathermy applied through a snare. SM injection was compared with no SM injection. Using post mortem porcine gastric and esophageal tissue a series of full thickness holes of 5-25 mm were cut using a scalpel. The hole was closed until watertight with stitches placed using an ESM with 3.0 nylon thread and knots tied with an endoscopic knot pusher. Based on these bench experiments, three live pig experiments were performed. An area in the body of the stomach was raised with 4 ml of normal saline injected via an endoscopic injection needle. The area was then converted into a polyp using a band ligation device. The polyp was 1.8 cm in diameter. Two stitches were applied on each side of the polyp using ESM. The stitches were left untied. The resection of the polyp was performed by using a snare diathermy. The mucosal defect was 2.5cm. No overt perforation was noted. The sutures were tied and cut using tying and cutting device. There was no perforation. The pig recovered uneventfully and survived. Results: 9/10 band polyp resections without preinjection caused small perforations compared to 1/10 with preinjection of 1-5ml of saline. The size of these perforations was 5-7mm. A single thread sewn either side of the resection margin was a more efficient method to close wounds. Holes closed=12; median hole size 2.25 mm; total number of stitches=33; total number of knots=21; total number of half hitches=84. Two stitches closed holes up to 5 mm, more stitches were required for larger holes. Excision of wide based and flat lesions was successful and safe in pig stomach. Conclusions: 1. Polypectomy of banded gastric tissue without prior saline injection caused perforations. 2. Preinjection with saline reduced the incidence of perforation. 3 Large gastrointestinal lesions can be excised safely by using stitched closure of the potential perforation with Endoscopic Sewing Machine suturing.

The Giant Knot: A New One-Way Self-Locking Secured Arthroscopic Slip Knot

Summary: A secure slip knot is very important in the field of arthroscopy. The new giant knot, developed by the first auther, has the properties of being a one-way self-locking slip knot, which is secured without additional half hitches and can tolerate higher forces to be untied. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 4 (May-June), 1999: pp 451–452

Completing arthroscopic knots with a broken suture limb

Arthroscopically inserted sutures may become damaged during insertion. This can lead to breakage of one limb of the suture before sufficient knots have been delivered to prevent slippage. We present a clinical example and a simple technique to arthroscopically deliver half-hitch knots with a broken suture limb. The technique utilizes a grasper which is attached to the broken suture limb. The grasper acts as a new post over which additional half hitches can be delivered, completing the knot. We have found this technique very useful in shoulder capsular reconstruction and rotator cuff repair.

Knot tying at flexible endoscopy

Four new knotting techniques were developed for use at flexible endoscopy: (1) half hitches tied with knot-pusher, (2) thread-locking device, (3) self-tightening slip-knot, and (4) externally releasable knot. Remoteness from site of action, access through small-diameter orifice, and difficulty in applying lateral traction to tighten knots are problems met in knot tying at endoscopy. All four knotting techniques were studied in experiments on postmortem human stomachs and used for radio-telemetry studies and anti-reflux operations in survival studies in dogs using endoscopic sewing techniques. Half hitches tied at endoscopy with a knot-pusher were also used in human studies to treat esophageal reflux and secure pH radio-telemetry capsules for long-term measurements. Externally releasable knots were used to secure nasogastric tubes to the stomach of five patients for long-term nutrition. Knot tying is feasible at flexible endoscopy by a variety of new techniques. Endoscopically tied knots can be as secure as surgically hand-tied knots and have been used successfully in man. (Gatrointest Endosc 1994;40:722-9.)

Immunoglobulin E, Mast Cells, Endogenous Antigens, and Arthritis

New aspects of the biology of the mast cell and its associated products may be important to the pathogenesis of arthritis. Mast cells may be activated in human arthritides as a result of a rapidly expanding list of peptides, including cytokines and neurotransmitters. The classic immunoglobulin E-coupled mast cell activation pathways may be used in the autoimmune diseases by way of autoantibody production involving the immunoglobulin E molecule itself. This can be shown to induce mediator release in vitro. The mast cell-derived products may play a role in both the early phases of synovitis as well as the chronic destructive phase.

The half-hitch knot: A rational alternative to the square knot

The half-hitch knot, an alternative to the square knot for tying a suture, has been presented. A square knot is satisfactory, but because of its configuration it is difficult to tie, and in actual practice it is seldom used. Instead, a series of half hitches is tied. A half-hitch knot is as secure as a square knot and much easier to tie. However, it too must be tied in proper configuration to be reliable. The technique for tying a half-hitch knot and some of its characteristics are described.