Knot-tying Technique Research Articles

Comparative strength of ligature points achieved by various surgical knot-tying techniques: an observational study using Maxon™ monofilament sutures.

Surgical knot-tying requires careful selection of the appropriate technique for optimal outcomes; however, evidence is lacking about the common ligation techniques combining square and slip knots (combination knots). This study investigates the strength of a combination knot, compared with other techniques. In this observational cohort study, we assessed the strengths of square, slip-granny, slip-reef, and combination knots using absorbable monofilament sutures, and compared them using ANOVA and a multilevel linear regression analysis. We also assessed the correlation between the number of throws and knot strength using Spearman's correlation analysis. Among 80 ligatures, ANOVA indicated significant differences in knot strength among the techniques (p < 0.01). Multilevel linear regression showed that a combination knot was stronger than a slip knot (p < 0.01) and comparable to a square knot (p = 0.0721). Secondary analysis indicated that for combination knots, five throws could achieve sufficient knot strength. Combination knots are as strong as square knots and stronger than slip knots, and thus present a reasonable option for surgical ligation.

WP8.13 - Validating Remote Basic Surgical Skills Certification: A Randomised Controlled Trial

Abstract Aims Simulation based training comprises a fundamental component of modern surgical education, necessitating the development and advancement of affordable, functional, and validated simulators. This study explored the effectiveness of using the Inovus Basic Surgical Skills (BSS) simulator in improving core surgical skills amongst junior trainees. Methods This was a multicentre, RCT between August 2022 – November 2022 involving junior trainees yet to complete a validated basic surgical skills course. All participants completed an initial series of basic surgical tasks, including a range of suturing and knot-tying techniques. Three parameters (objective scoring tool, time taken for task completion, self-assessment questionnaire) were used to evaluate each surgical skill. Subsequently, participants were randomly allocated to the intervention group (BSS simulator) for at home training, or the control group receiving no further training. Results 5 domains were assessed for suturing tasks through respect for tissue, motion and efficiency, visuo-spatial, suture quality and time taken. Knot-tying was assessed by quality and time taken. Independent samples t-test revealed no significant difference between control and intervention groups (p&amp;gt;0.05) despite improvement in task quality and reduced completion time. Self-assessment questionnaires revealed a significant (p&amp;lt;0.05) improvement in confidence performing more complex tasks in intervention groups. Conclusions Study results demonstrate an improvement in both the quality of basic surgical skills and reduced completion time with use of the BSS simulator. Participants report increased confidence post-intervention following use of the BSS simulator. Despite the limitation of a small sample size, these findings underpin the potential benefits of BSS simulator use for surgical education amongst trainees, increasing accessibility to surgical training through an exceptionally realistic remote training environment.

Innovating medical education: Development of an affordable, 3-D printed knot-tying simulator.

Three-dimensional (3-D) printing offers an innovative option to produce clinical simulators because of its low production costs and widespread availability. We aimed to develop a low-cost, 3-D printed knot-tying simulator that overcomes the barriers students face in self-directed skills development. Medical students completing a procedural residency preparation course (PRPC) completed a pre-survey with Likert scales and multiple choice questions to assess their perceptions of and barriers to self-directed knot-tying practice. Subsequently, a 3-D printed knot-tying simulator, which contains a progression of knot-tying challenges and a designated video curriculum, was designed. After utilising the simulator in a 1-hour, faculty-guided knot-tying session, PRPC students assessed the educational utility and usability of the simulator via a post-survey. The primary barriers students faced in engaging in self-directed knot-tying practice included limited accessibility to simulators and insufficient knowledge of knot-tying techniques. Many students (91.3%, n = 21) agreed that practicing with the simulator improved their knot-tying motor skills and was easy to use (100%, n = 23). Twenty-two (95.7%) students agreed that they would continue to use the simulator beyond the knot-tying session and PRPC. We demonstrate the educational utility and usability of a novel 3-D printed knot-tying simulator for medical education. Enabling students to engage in self-directed technical skills development is critical in developing surgical skills that can translate to clinical environments. Our simulator highlights the benefits of 3-D printers as an innovative, inexpensive option to improve the availability and accessibility to medical education tools.

Automated titanium fastener vs. hand-tied knots for prosthesis fixation in infective endocarditis.

To date, there is no evidence regarding the safety of automated titanium fastener compared with hand-tied knots for prosthesis fixation in infective endocarditis. Between January 2016 and December 2022, a total of 220 patients requiring surgery for infective endocarditis were included in this retrospective analysis. The primary study endpoint was re-endocarditis during follow-up. The secondary study endpoints included stroke onset, all-cause mortality, and a composite outcome of either re-endocarditis, stroke, or all-cause mortality during follow-up. Suture-securing with an automated titanium fastener was performed in 114 (51.8%) patients, whereas the conventional technique of hand knot-tying was used in 106 (48.2%) patients. The risk of re-endocarditis was significantly lower in the automated titanium fastener group, as shown in a multivariable proportional competing risk regression model (adjusted sub-hazard ratio 0.33, 95% confidence interval 0.11-0.99, p = 0.048). The multivariable Cox proportional hazards regression analysis showed that the automated titanium fastener group was not associated with an increased risk of stroke-onset or attaining the composite outcome, respectively, (adjusted hazard ratio 0.54, 95% confidence interval 0.27-1.08, p = 0.082), (adjusted hazard ratio 0.65, 95% confidence interval 0.42-1.02, p = 0.061). Also, this group was not associated with an increased risk of all-cause mortality, as demonstrated in the multivariable Poisson regression analysis (adjusted incidence-rate ratio 1.42, 95% confidence interval 0.83-2.42, p = 0.202). The use of automated titanium fastener device seems to be safe for infective endocarditis. Analyses of larger cohorts are required.

Comparison of Knot-Tying Techniques During the Arthroscopic Broström-Gould Procedure: Semiconstrained Freehand Versus Knot Pusher Techniques.

The arthroscopic Broström technique with or without Gould modification has been used to treat patients with anterior talofibular ligament injury who failed nonoperative management and progressed to chronic lateral ankle instability. However, some patients develop limited range of motion over the ankle joint postoperatively. To compare the clinical outcomes and midterm functional performance of knot-tying techniques between using a knot pusher and a semiconstrained freehand tie during arthroscopic Broström-Gould procedure with inferior extensor retinaculum (IER) augmentation. It was hypothesized that the semiconstrained freehand tie would provide better plantarflexion of the ankle joint compared with the knot pusher. Cohort study; Level of evidence, 3. Included were 135 consecutive patients with mild-to-moderate lateral ankle instability (mean age, 42.7 years; range, 16-78 years) who underwent an arthroscopic Broström-Gould procedure from March 1, 2016, to April 30, 2022. The patients were divided into 2 groups according to the tying technique used in the Gould modification: surgical tie using a knot pusher (KP group; n = 30) or a semiconstrained freehand tie (FT group; n = 105). Radiographic parameters and ultrasound dynamic testing were examined during the preoperative assessment. Preoperative and 2-year postoperative assessments comprised American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, visual analog scale for pain, and 12-Item Short Form Survey (SF-12) scores. The 2 groups had no differences in age, sex, or severity distribution in the preoperative assessment. American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, visual analog scale pain, and SF-12 scores were significantly better at the postoperative evaluation (all P < .05) in both groups. No significant difference was noted between groups in outcome scores. In the KP group, however, 7 out of 30 patients (23.3%) developed ankle stiffness with tightness when performing plantarflexion movement. No patients in the FT group reported similar symptoms. For mild-to-moderate chronic lateral ankle instability, we propose an arthroscopic Broström procedure with the addition of IER augmentation using a semiconstrained freehand tie to avoid overtightening the IER. This ensures favorable patient satisfaction and clinical outcomes without limitation of plantarflexion of the ankle joint and avoids the possible complication of stiffness with plantarflexion.

Meniscus-Side-Knot-tying Technique Instead of Capsular-Side-Knot-Tying in Arthroscopic Outside-In Meniscal Repair: A Small but Meaningful Modification

Arthroscopic outside-in meniscal repair technique, which was first described by Warren in 1985, including all its later modifications, involved tying the final knot on the outer surface of the capsule. Capsular-side knot-tying has reported complications such as catching sensory nerves under the knot with resultant postoperative focal sensory loss and paresthesia, as well as pain under the skin because of irritation from the knot. Meniscus-side-knot-tying technique involves tying the knot on the outer surface of the meniscus. Advantages of the meniscus-side knot-tying technique include the following: avoiding catching nerves under the knot; avoiding pain under the skin because of irritation from the knot; the tension of the sliding knot and the subsequent half hitches, which can be monitored accurately under vision; no skin incisions needed; no possibility of cutting the suture limbs while performing the skin incision between the two needle holes; and, the ability to suture tears in mobile parts of the meniscus without fixing them to the capsule like tears in the anterior horn of the lateral meniscus.

Endoscopic Proximal Hamstring Tendon Repair With Knotless Suture-Bridge Technique

Symptomatic proximal hamstring tendon tears are typically repaired surgically, with open incision and knot-tying technique. An endoscopic, knotless, suture-bridge repair technique is presented. Potential advantages include knotless simplicity, compression over a broad zone to improve tendon–bone healing, and decreased pain secondary to elimination of knots and the open incision and approach.

1050 Application of Bloom’s Taxonomy and Kolb’s Experiential Learning Theory While Designing Low-Cost Surgical Skills Courses for Junior Doctors &amp; International Medical Graduates (IMGs) in the NHS

Abstract Aim To design a surgical skills course underpinned by Bloom’s &amp; Kolb’s learning theory for junior doctors in the NHS. To develop an affordable skills course for the acquisition of the necessary skills &amp; confidence among junior doctors. Method RCSEd CPD approved 1-Day Surgical Skills Course with course fees of £95 was designed based on the learning theory and was attended by 12 foundation-level doctors (&amp;gt;60% IMGs). The course contents were Knot Tying, Suturing Technique, Skin-Lesions excision, Bowel Anastomosis &amp; Tendon Repair. All six levels of Bloom’s Taxonomy were adopted for the Knot Tying session and Kolb’s for designing the remaining skills sessions. Results There was the flexibility of learning for the delegates as someone with good clinical knowledge and skills was able to reach level 6 Taxonomy (e.g one-finger knot-tying techniques) rather than limiting to Level 3(Apply) as seen in the conventional courses. Kolb’s learning theory helped the delegates to enter the learning cycle through any stage adopting any learning cycle complementing IMGs with their wide concrete experience. 100% n = 11 delegates responded their course expectations were met. Avg.54.5%n = 6 strongly agreed &amp; 45.5%n = 5 agreed on improvement in their post-course surgical skills. Conclusions The low cost of the surgical skills course was found to be one of the confounding factors for the wide participation by junior doctors &amp; IMGs (54.5% n = 5 scored 5/5 &amp; 45.5% n = 6 scored 4/5 for appropriateness on course fees). Adapting these learning theories helped enhance the course outcomes by widening the horizons of skills acquisition.

A Video-Based Assessment Tool to Measure Intraoperative Laparoscopic Suturing Using a Modified Script Concordance Methodology

Laparoscopic suturing (LS) is a challenging laparoscopic skill to teach. Its complexity and nuances are not modeled or measured in current simulation and assessment platforms.The script concordance test (SCT) is used to assess clinical reasoning.The purpose of this study is to provide evidence for validity of this novel SCT based online assessment for LS skills. We designed a video-based online SCT for LS using a cognitive task analysis and expert panelists.The CTA yielded 4 LS domains: needle handling (NH), tissue handling (TH), knot tying techniques (KT) and operative ergonomics (OE). Five-point scales with anchoring descriptors from -2 to +2 were used. Scoring was based on a modified SCT methodology. The test was administrated to 37 subjects (18 experts and 19 novices). There was no time limit given. A different expert group from the minimal invasive surgery (MIS) panelist were recruited. Experts were defined as surgeons and fellows with LS experience of >25 cases annually. Validity was assessed by comparing SCT scores of experienced and inexperienced surgeons. Cronbach's alpha was used to assess the internal consistency of the test. The survey started off with 47 questions in each of the following domains: 13 NH, 4 TH, 20 KT and 10 OE. Thirty-seven surgeons (18 experts and 19 inexperienced surgeons). Questions that demonstrated a large discrepancy among experts and panelists with a weighted score difference more than 40 were discarded (n = 20). One question was discarded because it received a 100% score from all participants. This yielded 26 remaining questions in the following domains: 8 NH, 2 TH, 11 KT and 5 OE. The test reliability level (Cronbach a) was 0.80. The mean score was 72 ± 9% and 63 ± 15% (p = 0.02) for experts and inexperienced surgeons, respectively. The mean time to complete the test was 21 minutes. This study provides validity evidence for a novel intraoperative LS assessment. The variability of responses between experts and panelists suggests that SCT may capture the clinical differences/surgeon preferences in performing LS intraoperatively.

Types of Retears After Knot-tying and Knotless Suture Bridge Rotator Cuff Repair: A Systematic Review and Meta-analysis.

In conventional double-row repair for rotator cuff tears, tying the medial row of anchor sutures can strangulate the tendon. The knotless medial row technique has been recommended to improve vascularity and reduce retear rates. The researchers divided the retear pattern into 2 categories: type 1 (failure at the tendon-bone interface) and type 2 (failure at the musculotendinous junction with healed footprint). To compare studies on knot-tying versus knotless double-row repair for rotator cuff tears according to retear type and clinical and radiological outcomes. Systematic review; Level of evidence, 3. A search of the PubMed, Embase, Scopus, and Cochrane databases was performed following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included were studies that directly compared the knot-tying and knotless double-row techniques and provided postoperative patient-reported outcomes and retear rates. The Methodology Index for Non-Randomized Studies (MINORS) criteria were used for methodological quality assessment of the included studies. Odds ratios (ORs) were calculated for dichotomous outcomes, and mean differences (MDs) were calculated for continuous outcomes. Included were 12 studies (n = 1411 shoulders); 1 study had level 1 evidence, 3 studies had level 2 evidence, and 8 studies had level 3 evidence. The MINORS score ranged from 15 to 19, indicating that the methodology was fair to good. There was no statistically significant difference in retear rate between techniques (OR, 0.99; 95% CI, 0.67-1.47; P = .96); however, more type 1 retears were seen in the knotless technique (OR, 0.42; 95% CI, 0.23-0.77; P = .005), and more type 2 retears were seen in the knot-tying technique (OR, 3.15; 95% CI, 1.70-5.83; P = .0003). Higher postoperative Constant scores were seen in the knot-tying technique (MD, 1.28; 95% CI, 0.03-2.53; P = .04); however, there were no significant differences between techniques regarding other postoperative outcomes. There was no significant difference in overall retear rates between the knotless and knot-tying techniques, and both techniques demonstrated similar clinical outcomes. However, type 2 retear rates were significantly greater after knot-tying repair, and type 1 retear rates were significantly greater after knotless repair.

Designing a Plastic and Reconstructive Surgery Virtual Curriculum: Assessment of Medical Student Knowledge, Surgical Skill, and Community Building.

The COVID-19 pandemic displaced medical students from their rotations and into virtual classrooms. The authors aimed to develop a virtual curriculum with the goals for students to gain knowledge in plastic surgery, to acquire technical skills, and to be able to promote community. The authors developed a 4-week educational curriculum of topics in plastic surgery using the American Society of Plastic Surgeons Resident Education Curriculum and an online plastic surgery curriculum. Virtual flipped classroom case discussions and weekly surgical skills workshops were offered. Precourse and postcourse surveys were administered, and results were analyzed using IBM SPSS Statistics version 25.0. Three hundred three medical students and recent graduates enrolled in the course in June of 2020. One hundred eighty-two students completed the precourse survey (60 percent response rate), and of those, 50.0 percent ( n = 91) completed the postcourse survey for paired comparison. Students reported significant improvement in confidence discussing the relevant anatomy, workup, and surgical approaches to clinical cases, in addition to confidence in knowledge of all topic areas ( p < 0.001). Confidence in suturing and knot-tying techniques improved significantly among workshop participants ( p < 0.001). Students applying to residency programs this cycle felt significantly more prepared for subinternships ( p < 0.001) and significantly more connected to the community of applicants ( p < 0.001). The Plastic and Reconstructive Surgery Virtual Curriculum improved knowledge, surgical skills, and community in the field among medical student participants. This course may serve to provide a framework for structured virtual learning activities for students interested in plastic surgery and may have significant long-lasting utility for students interested in the field.

Designing a Plastic and Reconstructive Surgery Virtual Curriculum: Assessment of Medical Student Knowledge, Surgical Skill, and Community Building

PURPOSE: Virtual and interactive learning are the future of plastic surgery education.1 This shift is essential in the COVID-19 era, as medical students have been displaced from clinical rotations into virtual classrooms resulting in losses of traditional opportunities to learn about plastic and reconstructive surgery. The impact of this pandemic is far-reaching and may adversely influence interest in surgical specialties, diversity in anatomic knowledge, and hands-on surgical experience. We aimed to provide medical students worldwide with a virtual educational opportunity and developed the Plastic and Reconstructive Surgery Virtual Curriculum (PRSVC), a structured, four-week, flipped classroom course with virtual clinical case discussions and surgical skills workshops. Additional programming was available for medical students applying to or considering applying into plastic surgery residency programs to socialize with each other and build community. METHODS: We designed and implemented a structured, four-week educational curriculum, which included curated learning modules that covered main topics within plastic surgery. Students were provided daily assignments from the American Society of Plastic Surgeons Resident Education Curriculum and DeckerMed Plastic Surgery Core Curriculum, which were available to all enrolled participants free of charge. As an adjunct to the educational coursework, students had opportunities to participate in biweekly, small group virtual flipped classroom case discussions and weekly surgical skills workshops. Pre- and postcourse surveys were administered and analyzed using SPSS. RESULTS: In total, 303 medical students and recent graduates (43.4% fourth-years) from 18 countries enrolled in the course in June 2020. An estimated 182 students completed the precourse survey (60% response rate), and of those, 50.0% (n = 91) completed the postcourse survey for paired comparison. About two-thirds were medical students in the United States and the remaining one-third of students were from Canada and other international countries. Over one-third did not have home plastic surgery programs, and almost half of the participants reported having an educational experience scheduled for June 2020 cancelled due to the COVID-19 pandemic. Students reported significant improvement in confidence discussing the relevant anatomy, work-up, and surgical approaches to clinical cases, as well as confidence in knowledge of all topic areas (P < 0.001). Confidence in suturing and knot-tying techniques significantly improved among workshop participants (P < 0.001). Students applying to residency programs this cycle felt significantly more prepared for sub-internships (P < 0.001) and significantly more connected to the community of applicants (P < 0.001). CONCLUSIONS: The Plastic and Reconstructive Surgery Virtual Curriculum improved knowledge, surgical skills, and community in the field among medical student participants. This course may serve to inform other surgical subspecialties in developing similar virtual educational opportunities and also serve to provide a paradigm for structured virtual learning activities for students interested in plastic surgery. REFERENCE: 1. Ali K, Colchado D, Davis MJ, et al. Online resources in plastic surgery education: a toolbox for modern trainees and plastic surgeons. Plast Reconstr Surg Glob Open. 2020;8(7):e2894. Published 2020 Jul 17. doi:10.1097/GOX.0000000000002894

Comparative study between bipolar electro-cautery and knot-tying technique in total thyroidectomy

Abstract Introduction: Thyroidectomy could be considered as the commonest neck surgery in surgical practice. Proper thyroidectomy requires careful and meticulous devascularization of the gland with preservation of surrounding important structures. Haemostasis during thyroidectomy achieved by suture ligation, electro-cautery or vessel sealing devices. The traditional knot-tying method requires carful dissection which is time consuming and may lead to injury of laryngeal nerves or impairment of blood supply to parathyroid glands. Bipolar electro-cautery has precise delivery of electric current between its tips with no or limited thermal dispersion to surrounding structures. Advanced vessel sealing devices not always available and requires special disposable handles which increases the coast. Aim: This prospective comparative study aims at evaluating the outcome of thyroidectomy using bipolar in comparison with traditional thyroidectomy using suture ligation. Method: Total thyroidectomy was carried out on 60 patients, equally divided in two groups each 30 patients. First group, haemostasis has been achieved by suture ligation. In the second group bipolar electro-cautery has been used. Result: In group A (knot-tying) mean operative time was 124.7±5.2 min and estimated blood loss about 101±15.9 ml with significant P value in comparison with group B (bipolar) in which mean operative time was 103.9±7.8 min and blood loss about 80±16.2 ml. Significant P value regarding post operative pain but non significant regarding operative and post operative complications. Conclusion: Bipolar electro-cautery is a simple and effective in thyroidectomy with less operative time, blood loss and without increased incidence of complications. Key words: thyroidectomy; bipolar; suturless.

How to tie dangerous surgical knots: easily. Can we avoid this?

ObjectiveSecure knots are essential in all areas of surgical, medical and veterinary practice. Our hypothesis was that technique of formation of each layer of a surgical knot was important to...

A proposed model for a comprehensive virtual subinternship in vascular surgery

ObjectiveIn the present study, we sought to understand the challenges, advantages, and applications of a vascular surgery virtual subinternship (VSI) curriculum. MethodsOur institution hosted 25 students for two 4-week VSI rotations, one in July 2020 and one in August 2020. The students participated in a curriculum centered around the use of Zoom and telephone interactions with residents and faculty. The curriculum included selected readings, surgical videos, group didactics, and one-on-one mentorship. Anonymous pre- and postrotation self-assessments were used to ascertain the students' achievement of the learning objectives and the utility of the educational tools implemented during the rotation. The faculty and resident mentors were also surveyed to assess their experience. ResultsWith the exception of knot-tying techniques (P = .67), the students reported significant improvement in their understanding of vascular surgery concepts after the virtual elective (P < .05). The highest ranked components of the course were interpersonal, including interaction with faculty, mentorship, and learning the program culture. The lowest ranked components of the course were simulation training and research opportunities. The rating of the utility of aspects of the course were consistent with the ranking of the components, with faculty interaction receiving the highest average rating. The ideal amount of time for daily virtual interaction reported by the students ranged from 3 to 6 hours (median, 4 hours). Overall, most of the mentors were satisfied with the virtual course. However, they reported limited ability to assess the students' personality and fit for the program. The time spent per week by the mentors on the virtual vascular surgery rotation ranged from 2 to 7 hours (median, 4 hours). Of the 17 mentors completing the surveys, 14 reported that having a virtual student was a significant addition to their existing workload. ConclusionsOverall, our student and mentor feedback was positive. Several challenges inherent to the virtual environment still require refinement. However, the goals of a VSI are distinct and should be explored by training programs. With changes to healthcare in the United States on the horizon and the constraints resulting from the severe acute respiratory syndrome coronavirus 2 pandemic, implementing a virtual away rotation could be an acceptable platform in our adaptations of our recruitment strategies.

Effectiveness of the taut-line hitch knot in accurately determining the length of artificial chordae during repair for degenerative mitral insufficiency.

Taut-line hitch, a type of ropework used in outdoor activities, was adopted to tie the artificial chordae during mitral valve repair for degenerative mitral insufficiency. This knot-tying technique facilitated artificial chordae length determination during surgery. Nineteen patients with degenerative mitral insufficiency were successfully treated using this technique.

Differences of tensile strength in knot tying technique between orthopaedic surgical instructors and trainees

BackgroundKnot tying technique is an extremely important basic skill for all surgeons. Clinically, knot slippage or suture breakage will lead to wound complications. Although some previous studies described the knot-tying technique of medical students or trainees, little information had been reported on the knot-tying technique of instructors. The objective of the preset study was to assess surgeons’ manual knot tying techniques and to investigate the differences of tensile strength in knot tying technique between surgical instructors and trainees.MethodsA total of 48 orthopaedic surgeons (postgraduate year: PGY 2–18) participated. Surgeons were requested to tie surgical knots manually using same suture material. They were divided into two groups based on each career; instructors and trainees. Although four open conventional knots with four throws were chosen and done with self-selected methods, knot tying practice to have the appropriate square knots was done as education only for trainees before the actual trial. The knots were placed over a 30 cm long custom made smooth polished surface with two cylindrical rods. All knots were tested for tensile strength using a tensiometer. The surgical loops were loaded until the knot slipped or the suture broke. The tensile strength of each individual knot was defined as the force (N) required to result in knot failure. Simultaneously, knot failure was evaluated based on knot slippage or suture rupture. In terms of tensile strength or knot failure, statistical comparison was performed between groups using two-tailed Mann–Whitney U test or Fisher exact probability test, respectively.ResultsTwenty-four instructors (PGY6–PGY18) and 24 trainees (PGY2–PGY5) were enrolled. Tensile strength was significantly greater in trainees (83.0 ± 27.7 N) than in instructors (49.9 ± 34.4 N, P = 0.0246). The ratio of slippage was significantly larger in instructors than in trainees (P < 0.001). Knot slippage (31.8 ± 17.7 N) was significantly worse than suture rupture (89.9 ± 22.2 N, P < 0.001) in tensile strength.ConclusionsMean tensile strength of knots done by trainees after practice was judged to be greater than that done by instructors in the present study. Clinically, knot slippage can lead to wound dehiscence, compared to suture rupture.

Differences in Failure Mode Between Simple and Mattress Suture Configuration in Arthroscopic Bankart Repairs: A Cadaveric Study.

Background:Traumatic anterior shoulder dislocations disrupt the anteroinferior labrum (Bankart lesion), leading to high rates of instability and functional disability, necessitating stabilization.Purpose:To investigate modes and locations of repair failure between simple and horizontal mattress suture configurations after arthroscopic Bankart repair using suture anchors in a cadaveric model.Study Design:Controlled laboratory study.Methods:A total of 48 fresh-frozen human cadaveric shoulders from 48 specimens underwent creation of Bankart lesions from either the 3:00 to 6:00 o’clock position on the right glenoid or the 6:00 to 9:00 o’clock position on the left glenoid. Shoulder laterality between specimens was alternated and randomized to either simple or mattress suture repair configurations. In each shoulder, anchors were placed on the glenoid at the 3:00, 4:30, and 6:00 o’clock positions on the right or 6:00, 7:30, and 9:00 o’clock positions on the left and were secured via standard arthroscopic knot-tying techniques. Specimens were tested in the supine anterior apprehension position using a servohydraulic testing machine that was loaded to failure, simulating a traumatic anterior dislocation. After dislocation, open inspection of specimens was performed, and failure mode and location were documented. Differences in failure mode and location were compared using nominal multivariate generalized estimating equations.Results:Simple suture repairs most frequently failed at the labrum, while mattress suture repair failed at the capsule. Regardless of configuration, repairs failed most commonly at the 3:00 o’clock position on the right shoulder and 9:00 o’clock position on the left shoulder. Compared with mattress suture repairs, simple suture repairs failed at a significantly higher rate at the 6:00 o’clock position.Conclusion:Traumatic anterior shoulder dislocation after arthroscopic Bankart repair in a cadaveric model resulted in simple suture configuration repairs failing most commonly via labral tearing compared with capsular tearing in mattress repairs. Both repair configurations failed predominately at the anterior anchor position, with simple suture repairs failing more commonly at the inferior anchor position.Clinical Relevance:Horizontal mattress suture configurations create a larger area of repair, decreasing the risk of repair failure at the labrum. The extra time required for mattress suture placement at the inferior anchor position is used effectively, resulting in lower biomechanical failure rates.

Vertical Interfragmentary Doubled Suture for Displaced Patella Fractures: Sequential Compressive Tightening with Nice Knot.

In the treatment of displaced patella fractures, open reduction and internal fixation is essential for patellofemoral congruency and restoration of the knee extension mechanism. Various surgical techniques and materials can be used, and their clinical outcomes are favorable. However, soft-tissue and skin irritation, pain, and limited range of motion due to metallic hardware can occur, and removal of hardware such as screws and K-wire may be required after bony union. We present a vertical interfragmentary suture technique for patella fractures using sequential compressive tightening with the Nice knot. This knot-tying technique is low profile, provides stable fixation enough to hold displaced fractures, and does not require a secondary procedure for hardware removal.

Nonabsorbable Suture Knot on the Tendon Affects Rotator Cuff Healing: A Comparative Study of the Knots on Tendon and Bone in a Rat Model of Rotator Cuff Tear

Background: Nonabsorbable suture knots are usually used to link the tendon and bone during rotator cuff repair surgery. There are many variations in the arthroscopic knot-tying technique; however, the location of suture knot placement for rotator cuff healing has rarely been studied. Hypothesis: The authors compared the rotator cuff healing between knots tied on tendon and bone in a rotator cuff tear rat model. It has been hypothesized that knots can cause chronic inflammation and create the weakest link between tendon and bone, thus affecting rotator cuff healing. Study Design: Controlled laboratory study. Methods: Bilateral supraspinatus tenotomy and rotator cuff repair at the greater tuberosity were performed on 24 Wistar rats. Nonabsorbable surgical suture knots were made on the right supraspinatus tendon tissue and left humerus inferior to the greater tuberosity, respectively. Twelve rats each were sacrificed at 3 and 9 weeks. Six of the 12 rats were used for biomechanical testing and the remaining 6 for histologic evaluation. Results: The surgical knots placed on the bursal side of the tendon migrated to the articular side, as noted on gross observation in 22 of 24 samples. The knots on the tendon group showed significantly inferior tendon-bone integration and significantly inferior biomechanical results in terms of maximum load to failure and stiffness. An obvious chronic foreign body inflammatory reaction was found in the knots on the tendon group at 3 and 9 weeks. Furthermore, inferior bone-tendon interface regeneration and weakest link formation were obtained in the knots on the tendon group compared with those on the bone group. Conclusion: Nonabsorbable suture knots placed on the tendon migrate to the articular side, causing chronic inflammation and weakening tendon-bone healing, which may explain some retears after rotator cuff repair. Clinical Relevance: The present animal study suggests that it is not recommended in clinical practice to make several bulky nonabsorbable suture knots on the rotator cuff tendon during rotator cuff repair surgery. It may be better to tie the knots at the bone side or do knotless repair.