Properties Of Suture Materials Research Articles

Assessment of the Mechanical Properties of Different Suture Materials for Oral Surgery: An In Vitro Tensile Strength Study.

Sutures are essential components of wound closure in oral surgery, and the mechanical properties of suture materials play a crucial role in determining surgical outcomes. Understanding the tensile strengths of various suture materials is vital for selecting the most appropriate material for specific clinical applications. This study aimed to assess the tensile strength of suture materials commonly used in oral surgery through an in vitro tensile strength study. A total of 192 samples of six commonly used suture materials (polyglycolic acid (PGA), polyglactin 910 (PGLA), polylactic acid (PLA), polydioxanone (PDO), silk, and nylon) were subjected to tensile strength testing using a universal testing machine. Descriptive statistics were used to summarize the tensile strength of each suture material. A comparative analysis was conducted using appropriate statistical tests to identify any significant differences in the tensile strength among the different materials. Significant variability in tensile strength was observed among the suture materials in newtons (N). PGLA exhibited the highest mean tensile strength (38.7 N), followed closely by PDO (37.1 N), whereas silk displayed the lowest tensile strength (32.8 N). Comparative analysis revealed significant differences in the tensile strength among the materials (p < 0.001). This study provides valuable insights into the mechanical properties of the suture materials commonly used in oral surgery. These findings underscore the importance of considering tensile strength when selecting suture materials for specific clinical scenarios, thereby optimizing wound closure techniques and improving patient outcomes.

Knot Security 101: A Comprehensive Practical Review to Optimal Knot Configuration, Pulling Direction, Throw Count, and Tail Length.

Knots are the weakest structural point in a suture line and inevitably weaken almost all suture materials. This practical review critically evaluates the factors, such as suture material properties, gauge, configuration, throw count, and tail length, that affect knot security. A PubMed search between the years 1934 and 2023 identified relevant studies that addressed factors relating to knot security. Studies that investigated knots and sutures solely used in laparoscopic and arthroscopic surgery were excluded. Knot configurations assessed were the Aberdeen, sliding, square, and surgeon's. Eighty-six articles were included in this review article and demonstrated that knot security varies greatly between suture materials and gauge. Knot security also varies by configuration, throw count, conditions, tail length, and stitch type. Throw count differs by knot configuration, with the Aberdeen knot being most secure with three throws and one to two turns compared with three to five throws for surgeon's and square knots. The optimal tail length was 3 mm. This practical review demonstrates that there are significant differences in knot security based on a variety of factors. It is challenging to propose an ideal knot because most studies did not evaluate knot security using a broad variety of suture materials, gauges, and throws for each of the most common knots. Although this review article demonstrated several applicable findings, additional robust studies are needed to simplify proposals.

Review On Biological Properties of Suture Materials

Suture is a general term for all materials used to stitch torn tissues. Surgical sutures are imperative in management of surgical and traumatic wounds. Sutures are primarily used to oppose tissues together to assist and accelerate the recovery process after an incident or surgical operation. In addition, sutures also aid in obliteration of dead space, even distribution of stress on the incision line, and maintenance of adequate tensile strength throughout the critical wound healing process until appropriate tissue strength is achieved. Considering availability of a wide variety of suture materials, it’s important to know the differences between various sutures before making an informed decision. Suture material's overall performance is influenced by its physical qualities, handling features, and biological factors. The aim of this seminar paper is to give highlights on the biological properties of suture materials. Suturing is not simply about closing a wound; it is a skill that requires finesse and can significantly impact the healing process, reduce complications, and even affect long-term results. Suture selection involves the choice of both the appropriate type and size of suture material. Sutures may cause different host reactions in living tissues. While the suture remains in the tissue, it can trigger the inflammation cascade through different pathways such as degradation, a foreign body reaction, an allergic reaction, or abrasion. Natural suture materials such as catgut and silk are more immunogenic than synthetic materials because they are degraded by proteolysis in contrast to synthetic suture materials, which are degraded by hydrolysis. Therefore, surgery professionals should choose a suture material with good tissue acceptance.

Effectiveness of Continuous versus Interrupted Closure of Midline Wound in Emergency Laparotomies in Terms of Wound Dehiscence

Background: Midline laparotomy is widely recognized as the preferred technique for abdominal surgeries due to its simplicity and the effective exposure it provides. Despite its prevalence, the optimal method for closing the incision remains a topic of debate among surgeons, particularly when balancing the risk of wound dehiscence with the practicalities of surgical practice. The mechanical properties of suture materials and techniques, such as continuous versus interrupted suturing, directly influence wound integrity during the critical postoperative period. Objective: The aim of this study was to compare the effectiveness and complication rates of continuous versus interrupted suturing techniques in midline laparotomies, with a focus on the incidence of wound dehiscence. Methods: This randomized controlled trial included 180 patients undergoing emergency laparotomy, divided into two groups: continuous closure (Group A) and interrupted closure (Group B). The study was conducted at Lady Reading Hospital MTI, Peshawar, with ethical committee approval. Participants were informed, consented, and demographic data were recorded. Suture techniques were performed by an experienced surgeon, and patients were monitored for wound dehiscence up to the 15th postoperative day. Data were analyzed using SPSS version 25. Results: Group A reported a wound dehiscence rate of 14.4%, with an effectiveness rate of 85.6%. In comparison, Group B showed a significantly lower dehiscence rate of 5.6% and an effectiveness rate of 94.4%. The age-wise distribution of effectiveness indicated no statistically significant difference between the groups across various age ranges, with P-values ranging from 0.2766 to 0.6037. Gender-wise, males and females also did not show significant differences in effectiveness between the two groups. Conclusion: Interrupted suturing for midline laparotomy closures showed a lower incidence of wound dehiscence compared to continuous suturing. However, factors such as increased surgery time and cost, along with postoperative issues like stitch sinus formation, need consideration. Further large-scale studies are recommended to evaluate the long-term outcomes and provide a more comprehensive assessment of the two techniques.

Comparative experimental study of biomechanical features of suture materials in tendon repair

Introduction Many different suture configurations and pathomorphology of tendon repair have been described for tendon repair over the past 20 years. However, the biomechanical properties of suture material at primary flexor tendon repair have not been sufficiently explored. A cyclic loading test is performed to evaluate the performance of the different sutures under repeated loading conditions simulating dynamic conditions in postoperative rehabilitation procedures.The objective was to compare the strength of suture materials under cyclic loading on a biological model of a tendon.Material and methods Eighty porcine digital flexor tendons were examined in a pilot study. The sutured tendons were tested with a universal testing machine. Tendon repair was produced using polypropylene in group I, braided polyamide suture in group II, complex polytetrafluoroethylene thread in group III and a thread of superelastic titanium nickelide in group IV. The standard Chang protocol was used for cyclic loading.Results The percentage of intact sutures was 25 % in group I and in group II, 80 % in group III and 85 % in group IV after completing the entire load cycle. A pairwise comparison showed suture disruption being more common for group I and group II as compared to group III and group IV. Irreversible gap was more common for group 1 as compared to group IV. Neither knot ruptures nor tissue cutting were seen in the groups.Discussion The topic of biomechanical properties of suture material remains poorly understood. Although static load testing is commonly used in current experimental studies and cyclic testing is suitable for simulating postoperative conditions. The search continues for the “ideal” suture material for flexor tendon repair to prevent tears and retain tensile properties until the repair reaches strength.Conclusion The threads of polytetrafluoroethylene and nickelide-titanium showed the best biomechanical properties for tendon repair in the form of linear strength, good elasticity and low plasticity of the suture material. There were no significant differences between polypropylene and braided polyamide threads.

The effect of argon plasma coagulation on surgical suture material

Introduction. In modern surgery, there are many types of different energy used to achieve hemostasis; one of them is the energy of argon plasma coagulation. However, the impact of energy affects not only the bleeding site; it also affects the stitches lying nearby the source of bleeding. The instructions for the use of a suture material or a coagulation tool do not describe the changes that may occur when they interact. A review of the literature found a small number of publications devoted to changes in the physical properties of suture material when exposed to it. This information is not sufficient to predict the effects of argon plasma coagulation energy on the suture material and, as a result, on wound healing or the quality of the postoperative scar.The objective was to determine changes in the biodestructive properties of synthetic absorbable suture materials with argon plasma coagulation in an in vivo experiment.Methods and materials. In the experimental study, the results of biodegradation of monofilament and polyfilament sutures after exposure to argon plasma coagulation energy were analyzed in comparison with control samples in the body of laboratory mice.Results. It can be unequivocally stated that the effect of argon plasma coagulation energy has an effect on the rate of biodegradation of both monofilament and polyfilament synthetic filaments implanted in muscle tissue.Conclusions. Suture material exposed to argon plasma coagulation may not meet the terms of partial or full biodegradation stated by the manufacturer, which may affect the quality of scar formation.

An Evaluation of the Tensile Strength of Polyglactin Sutures After Immersion in Different Herbal Mouthwashes: An In Vitro Study.

Background The process of suturing is essential to the healing of surgical wounds. Sutures on surgical wounds from fabric approximate ligament tissues, control haemorrhage, and assist the primary healing process in oral surgical procedures. The oral environment may cause the suture to lose its tensile strength, which causes tissue to open and spread infection. Different mouthwashes are recommended for effective oral hygiene maintenance postoperatively. Ideally, the use of mouthwashes should not alter the mechanical properties of suture materials. A suture material's tensile strength or ability to endure tension during knotting and long-term wound protection is measured. Aim The aim of the current study is to assess the tensile strength of polyglactin sutures following immersion inherbal mouthwashes. Methods Two commercially available synthetic braided polyglactin 910 absorbable sutures (Vicryl and Seamcryl) were chosen to assess their tensile strength following immersion in two kinds of herbal mouthwashes: nilavembu (Andrographis paniculata) silver nanoparticle mouthwash and clove-uni stevia mouthwash. The tensile strength of the sutures was evaluated using an ElectroPuls® E3000 (Instron, Norwood, MA, USA) universal testing machine. The data were transferred to IBM Statistical Package for Social Sciences (SPSS) software version 23.0 (IBM Corp., Armonk, NY, USA), wherein the tensile strength values of Vicryl and Seamcryl after immersion in two different mouthwashes compared with control were statistically analysed using a one-way analysis of variance (ANOVA) test. Results The tensile strength of Vicryl suture material was found to be higher in the clove-uni stevia mouthwash group than in the nilavembu silver nanoparticle mouthwash and control (p-value=0.000, which is statistically significant). The tensile strength of Seamcryl suture material was found to be higher in the clove-uni stevia mouthwash group than in the nilavembu silver nanoparticles mouthwash and control (p-value=0.001, which is statistically significant). Conclusion Nilavembu silver nanoparticle mouthwashes analysed in the present study decreased the tensile strength property of Vicryl suture material after immersion for 24 hours, whereas clove-uni stevia mouthwash was shown to increase the tensile strength of both Vicryl and Seamcryl suture materials. Therefore, the selection of suture material and the postoperative prescription of mouthwash should be considered for a better clinical outcome.

Individualized Wound Closure-Mechanical Properties of Suture Materials.

Wound closure is a key element of any procedure, especially aesthetic and reconstructive plastic surgery. Therefore, over the last decades, several devices have been developed in order to assist surgeons in achieving better results while saving valuable time. In this work, we give a concise review of the literature and present a biomechanical study of different suturing materials under mechanical load mimicking handling in the operating theatre. Nine different suture products, all of the same USP size (4-0), were subjected to a standardized crushing load by means of a needle holder. All materials were subjected to 0, 1, 3 and 5 crushing load cycles, respectively. The linear tensile strength was measured by means of a universal testing device. Attenuation of tensile strength was evaluated between materials and between crush cycles. In the pooled analysis, the linear tensile strength of the suture materials deteriorated significantly with every cycle (p < 0.0001). The suture materials displayed different initial tensile strengths (in descending order: polyglecaprone, polyglactin, polydioxanone, polyamid, polypropylene). In comparison, materials performed variably in terms of resistance to crush loading. The findings were statistically significant. The reconstructive surgeon has to be flexible and tailor wound closure techniques and materials to the individual patient, procedure and tissue demands; therefore, profound knowledge of the physical properties of the suture strands used is of paramount importance. The crushing load on suture materials during surgery can be detrimental for initial and long-term wound repair strength. As well as the standard wound closure methods (sutures, staples and adhesive strips), there are promising novel devices.

Effect of Common Mouthwashes on Mechanical Properties of Suture Materials Used in Dental Surgeries: A Laboratory Experiment.

Background: Sutures play a pivotal role in promoting healing in any surgical procedure. However, the versatile nature of the oral environment entails additional properties in the suture materials to assure uneventful healing. A surgeon needs to understand these delicate intricacies in the immediate postoperative phase and needs some kind of algorithm in the selection of sutures that suits the different surgical scenarios. Therefore, a study was designed to observe the effect of four different types of mouthwash, viz. Avohex, Aloedent, Parodontax and Betadine, on the mechanical properties of Vicryl (polyglactin 910), PTFE (polytetrafluoroethylene), Prolene (polypropylene) and Mersilk. Methods: A total of 288 suture samples were divided in four equal groups (72 = each group) and used for the experiments. Tensile load, tensile strength as well as percentage elongation of the suture materials were evaluated in the various stated media at 3rd, 7th, 10th and 14th days, which were compared with the controls. The results were analyzed statistically and inferences were drawn. Results: Mersilk in (Avohex, Parodontax and Betadine) solutions showed a statistically significant decrease in tensile load over time. All the sutures had the highest tensile strength in Parodontax and had the lowest in Betadine solution. Vicryl and PTFE presented significant percentage elongation over time as compared to Prolene and Mersilk. Conclusion: The author has given certain recommendations but also states that there is no standard rule for the use of a particular suture material in all clinical situations. However, the selection of the suture material should be based on the type of surgery and preferences of the surgeon.

Results of Evaluation of the Physical and Mechanical Properties of a New Suture Material with Miramistin Coating

Background: The imperfection of surgical sutures, from the point of view of insufficient prevention of microbial contamination in the area of suturing, is one of the urgent problems in modern practical healthcare. In this connection, one of the promising areas at the present time is the study of suture material under conditions of its coating with various antiseptics. This study aimed to evaluate the physical and mechanical properties of the suture material impregnated with miramistin for further application in experimental studies on animals. Methods and Results: By applying a two-layer polymer coating on absorbable polyglycolide threads, the threads were given antimicrobial properties. In the amount of 10% or 20% by weight of the polymer, miramistin was introduced into both coatings. The breaking load and elongation data in the surgical suture knot were evaluated by immersing the samples in a phosphate buffer solution (pH=7.4), maintaining a constant temperature of 37°C by a thermostat. Threads from the solution were extracted on Days 1, 3, 7, 14, and 21 of the experiment. Further, the studied samples of the suture material were subjected to stretching to rupture on a universal tensile testing machine of the domestic company Metrotest. Physical and mechanical properties were evaluated by the dynamics of the breaking load and elongation at a break in the node after being in a phosphate buffer solution. Coating of polyglycolide thread, which is a suture material, with miramistin at a concentration of 10% and 20% does not lead to loss of strength even in the long term of the experimental study, which, in turn, meets the standards for suture material. Conclusion: The results obtained allow us to recommend a suture material impregnated with miramistin for further research, the ultimate goal of which will be the possibility of active use of this material in practical medicine, in particular in surgery to prevent microbial contamination in the area of suturing and infection of wounds.

Does skin preparation alter suture strength characteristics? Assessing the effect of chlorhexidine and isopropyl alcohol on common skin closure suture material.

Sutures are essential to approximate tissues and enable healing by first intention until a wound regains its original tensile strength. The mechanical properties of sutures are well documented, but the effects of exposing sutures to skin preparation solutions used in surgery are not. This study was performed to investigate whether 2% chlorhexidine and 70% isopropyl alcohol skin preparation, commonly used prior to incision and prior to closure, has any effect on the mechanical properties of several commonly used surgical suture types. Four suture types were soaked in either 2% chlorhexidine and 70% isopropyl alcohol or Hartmann's solution for 5 minutes. All sutures were left to dry for 11 days before being tested to failure using an Instron 3367 tensile testing machine. Testing revealed significant differences in failure load, ultimate tensile stress, and Young's modulus between suture types (P < .05). No significant differences in failure load (P = .98), ultimate tensile stress (P = .21), or Young's modulus (P = .22) were observed between the test group and the control group when comparing sutures of the same type. This study demonstrates that chlorhexidine/isopropyl skin preparation solutions do not significantly change the mechanical properties of suture materials exposed to them.

Research of physical and mechanical characteristics of suture material in experiment in operations on liver

Taking into account the peculiarities of the blood supply to the liver and the structure of its parenchyma, and, as a result, considerable difficulties in providing reliable hemostasis without additional traumatization, a surgeon needs to be careful when performing a surgical manipulation. Despite a large number of modern methods for stopping parenchymal bleeding, many practi-tioners give preference to classic methods of hemostasis, including ligation of bleeding vessels in the bulk of the organ using specialized sutures. One of the most serious complications of the use of suture material is cutting of organ tissue, which leads to enhanced bleeding and expansion of the area of damage. At the moment, the tactics of choosing suture material for surgical procedures is empirical. In this context, the aim of this study was to assess the physico-mechanical properties of suture material regarding its structure, and to develop a criterion for choosing surgical sutures for surgical procedures. For the study, the liver was removed out of corpses of males of 35 to 40 years of age, after which separate sections of 7.574 cm in size were obtained from it. Then a wound 3 cm long and 2 cm deep was made. The wound was sutured with a simple interrupted suture without tightening, but with application of one simple half-node. For suturing, catgut, twisted capron and polyglycolide thread were used. Attention was paid to the maximal force applied at the moment of cutting (Fmax) and the degree of pulling the thread at the moment of cutting (Lu). The analysis of the data was based on comparison of Fmax and Lu parameters. This method permits to refuse from the empirical approach to the choice of suture material for operations on the liver, and to develop a criterion for choosing surgical sutures.

The Biomechanical Properties of Suture Materials and Their Relationship to Bacterial Adherence

Sutures are classified into non-absorbable and absorbable, and mechanical properties of these materials vary by the composition. In this study we analyze four different types of sutures used commonly in surgery: silk, nylon, polyglycolic acid (PGA) and polytetrafluoroethylene (PTFE). The materials were chosen to represent a wide range of suture material categories: absorbable and nonresorbable, monofilament and multifilament, natural and synthetic in order to assess their mechanical properties but also the bacterial adherence to each type. The objective of this study was to measure the total bacterial adherence by using real time PCR at 7 days postop and to analyze the antibacterial and mechanical properties comparatively depending on the type and composition of sutures. Tensile properties such as maximum tensile load, elongation rate, stiffness and energy absorbed before breakage were taken into consideration. Experimental determination pointed out that the average total bacterial load was lowest for PTFE and highest for silk. The results of the study are useful in choosing an appropriate suture wire according to the mechanical properties taking into account the bacterial load of the surgical site in order to aid in tissue repair.

A Biomechanical Comparison of Different Suture Materials Used for Arthroscopic Shoulder Procedures

To evaluate the viscoelastic properties of 4 commercially available cord-like sutures and 2 commercially available suture tapes when subjected to physiological loads, as well as to compare them with each other and to identify the clinically most desirable combination of suture material properties. Six suture materials (Ethibond, FiberWire, FiberTape, Orthocord, Ultrabraid, and Ultratape) underwent creep testing (n= 7, 60 N, 10 minutes) to determine specimen stiffness, initial elongation at 60 N of load, static creep (during 10 minutes of loading), and relaxed elongation (material recovery 3 minutes after removal of load). Furthermore, cyclic testing (n= 7, 10-45 N, 0.5 Hz, 500 cycles) was carried out to determine dynamic creep, peak-to-peak displacement, and relaxed elongation. Mechanical testing was conducted on a material testing machine in 37°C phosphate-buffered saline solution. FiberTape showed the greatest stiffness (23.9 ± 3.2 N/mm, P < .001), the smallest amounts of static (0.38 ± 0.10 mm, P < .001) and dynamic (0.16 ± 0.09 mm, P= .003) creep, and the smallest peak-to-peak displacement (0.20 ± 0.02 mm, P < .001). FiberTape and FiberWire showed the smallest initial elongation (1.17 ± 0.17 mm and 1.63 ± 0.25 mm, respectively; P<.001). Ultrabraid showed the greatest relaxed elongation, both statically (4.73 ± 0.73 mm, P < .001) and dynamically (4.18 ± 0.83 mm, P = .002). FiberTape consistently displayed less creep, greater stiffness, and less extensibility than the other suture types. Ultrabraid showed the largest amount of relaxed elongation on both static and dynamic testing. When considering high stiffness in combination with low initial extension and low static creep to be ideal parameters to achieve optimal initial construct stability and considering low dynamic creep in combination with low peak-to-peak displacement to be ideal conditions for the repetitive loading of the construct during the healing process, tapes seem to be superior to cord-like sutures for performing rotator cuff repair.

In Vivo Restoration of Myocardial Conduction With Carbon Nanotube Fibers.

Impaired myocardial conduction is the underlying mechanism for re-entrant arrhythmias. Carbon nanotube fibers (CNTfs) combine the mechanical properties of suture materials with the conductive properties of metals and may form a restorative solution to impaired myocardial conduction. Acute open chest electrophysiology studies were performed in sheep (n=3). Radiofrequency ablation was used to create epicardial conduction delay after which CNTf and then silk suture controls were applied. CNTfs were surgically sewn across the right atrioventricular junction in rodents, and acute (n=3) and chronic (4-week, n=6) electrophysiology studies were performed. Rodent toxicity studies (n=10) were performed. Electrical analysis of the CNTf-myocardial interface was performed. In all cases, the large animal studies demonstrated improvement in conduction velocity using CNTf. The acute rodent model demonstrated ventricular preexcitation during sinus rhythm. All chronic cases demonstrated resumption of atrioventricular conduction, but these required atrial pacing. There was no gross or histopathologic evidence of toxicity. Ex vivo studies demonstrated contact impedance significantly lower than platinum iridium. Here, we show that in sheep, CNTfs sewn across epicardial scar acutely improve conduction. In addition, CNTf maintain conduction for 1 month after atrioventricular nodal ablation in the absence of inflammatory or toxic responses in rats but only in the paced condition. The CNTf/myocardial interface has such low impedance that CNTf can facilitate local, downstream myocardial activation. CNTf are conductive, biocompatible materials that restore electrical conduction in diseased myocardium, offering potential long-term restorative solutions in pathologies interrupting efficient electrical transduction in electrically excitable tissues.

Choosing Sutures in Small Animal Surgery

The range of available sutures has increased over the last decades This has assisted veterinary surgeons to select sutures that are appropriate for each wound taking into account that typical healing rate of the tissue concerned might be influenced by local conditions and systemic factors Generally sutures are classified according to suture material properties and surgical needle characteristics When choosing sutures veterinary surgeons should always consider which is the appropriate suture material surgical needle and suture size for a given tissue and be familiar with suture characteristics and tissue requirements In this mini review sutures that are most commonly used in veterinary practices are described and recommendations for suture selection in different tissue types are discussed Surgeon rsquo s preferences should also be taken into account

Mechanical properties of suture materials in general and cutaneous surgery

Comprehensive studies comparing tensile properties of sutures are over 25 years old and do not include recent advances in suture materials. Accordingly, the objective of this article is to investigate the tensile properties of commonly used sutures in cutaneous surgery. Thirteen 3-0 sized modern sutures (four nonabsorbable and nine absorbable) were tensile tested in both straight and knotted configurations according to the procedures outlined by the United States Pharmacopeia. Glycomer 631 was found to have the highest failure load (56.1 N) of unknotted absorbable sutures, while polyglyconate (34.2 N) and glycomer 631 (34.3 N) had the highest failure loads of knotted absorbable sutures. Nylon (30.9 N) and polypropylene (18.9 N) had the greatest failure loads of straight and knotted nonabsorbable sutures, respectively. Polydioxane was found to have the most elongation prior to breakage (144%) of absorbable sutures. Silk (8701 MPa) and rapid polyglactin 910 (9320 MPa) had the highest initial modulus of nonabsorbable and absorbable sutures, respectively. The new data presented in the study provide important information for guiding the selection of suture materials for specific surgeries.

Characterization of craniofacial sutures using the finite element method

Characterizing the biomechanical behavior of sutures in the human craniofacial skeleton (CFS) is essential to understand the global impact of these articulations on load transmission, but is challenging due to the complexity of their interdigitated morphology, the multidirectional loading they are exposed to and the lack of well-defined suture material properties. This study aimed to quantify the impact of morphological features, direction of loading and suture material properties on the mechanical behavior of sutures and surrounding bone in the CFS. Thirty-six idealized finite element (FE) models were developed. One additional specimen-specific FE model was developed based on the morphology obtained from a µCT scan to represent the morphological complexity inherent in CFS sutures. Outcome variables of strain energy (SE) and von Mises stress (σvm) were evaluated to characterize the sutures’ biomechanical behavior. Loading direction was found to impact the relationship between SE and interdigitation index and yielded varied patterns of σvm in both the suture and surrounding bone. Adding bone connectivity reduced suture strain energy and altered the σvm distribution. Incorporating transversely isotropic material properties was found to reduce SE, but had little impact on stress patterns. High-resolution µCT scanning of the suture revealed a complex morphology with areas of high and low interdigitations. The specimen specific suture model results were reflective of SE absorption and σvm distribution patterns consistent with the simplified FE results. Suture mechanical behavior is impacted by morphologic factors (interdigitation and connectivity), which may be optimized for regional loading within the CFS.

Characterization of tetracycline hydrochloride drug incorporated silk sutures

In this work, tetracycline hydrochloride (TCH) has been applied onto silk sutures at three different concentrations and the effect of TCH concentrations on the characteristics of the silk sutures was studied. The result showed that TCH concentration in the selected range has no significant effect on frictional behavior, tenacity, and knot strength of silk sutures. In vitro drug release study showed that the amount of drug released from the silk sutures has a positive relation with the concentration of the drug. Antimicrobial test results showed that the TCH treated silk suture exhibits greater antimicrobial activity against gram-negative bacteria Escherichia coli than gram-positive bacteria Staphylococcus aureus. Furthermore, the antimicrobial activity increases with the concentration of the drug. At higher concentration of TCH, zones of inhibition of 32 and 25 mm were observed against E. coli and S. aureus, respectively. The scanning electron microscope (SEM) study reveals the deposition of TCH onto the surface of silk sutures. Also, the adhesion of E. coli and S. aureus bacteria onto the surface of untreated silk sutures was confirmed by SEM. In conclusion, our results suggest that TCH containing silk suture does not generate more friction and less tenacity and knot strength than the untreated silk sutures. These characteristics combined with good drug release and antimicrobial characteristics suggest that TCH drug is suitable to improve the functional properties of suture materials.

The Role of the Sutures in Biomechanical Dynamic Simulation of a Macaque Cranial Finite Element Model: Implications for the Evolution of Craniofacial Form

The global biomechanical impact of cranial sutures on the face and cranium during dynamic conditions is not well understood. It is hypothesized that sutures act as energy absorbers protecting skulls subjected to dynamic loads. This hypothesis predicts that sutures have a significant impact on global patterns of strain and cranial structural stiffness when analyzed using dynamic simulations; and that this global impact is influenced by suture material properties. In a finite element model developed from a juvenile Rhesus macaque cranium, five different sets of suture material properties for the zygomaticotemporal sutures were tested. The static and dynamic analyses produced similar results in terms of strain patterns and reaction forces, indicating that the zygomaticotemporal sutures have limited impact on global skull mechanics regardless of loading design. Contrary to the functional hypothesis tested in this study, the zygomaticotemporal sutures did not absorb significant amounts of energy during dynamic simulations regardless of loading speed. It is alternatively hypothesized that sutures are mechanically significant only insofar as they are weak points on the cranium that must be shielded from unduly high stresses so as not to disrupt vitally important growth processes. Thus, sutural and overall cranial form in some vertebrates may be optimized to minimize or otherwise modulate sutural stress and strain.