Systematic review and meta-analysis of surgical suture strength according to the type, structure and geometry of suture materials

Purpose: As a rule, wound healing is a natural and spontaneous process. However, in acute or surgical wounds, the wound edges need to be approximated and held together by artificial means. Surgery within the abdominal cavity or elsewhere almost always involves cutting through the skin, after which a medical procedure is conducted, followed by wound closure. The suture provides temporary mechanical support during the natural healing process of the affected tissues. Not only does it stimulate the primary wound healing, but also provides mechanical protection against wound dehiscence. Methods: This analysis is intended to juxtapose the basic factors that contribute to a change in suture strength and the possible failure of surgical sutures, which may affect the wound healing process and increase the risk of postoperative complications. Results: The preliminary search criteria used in the databases included keywords such as: “strength of suture materials”, “strength of surgical sutures”, “surgical knot strength”. Five key articles were ultimately selected from a pool of 336 articles first identified based on these search criteria. Next, a meta-analysis of the literature data was performed, taking into account factors such as the type of suture materials used, biological conditions and model conditions used in research, having a significant impact on the mechanical properties of surgical sutures. Conclusions: This comparison revealed considerable variations in the suture strength between different sutures of the same size, it also demonstrated that the decrease in suture strength strongly depends on the finished suture and the thread type.

Systematic review and meta-analysis of surgical suture strength according to the type, structure and geometry of suture materials

PURPOSE

As a rule, wound healing is a natural and spontaneous process. However, in acute or surgical wounds, the wound edges need to be approximated and held together by artificial means. Surgery within the abdominal cavity or elsewhere almost always involves cutting through the skin, after which a medical procedure is conducted, followed by wound closure. The suture provides temporary mechanical support during the natural healing process of the affected tissues. Not only does it stimulate the primary wound healing, but also provides mechanical protection against wound dehiscence.

METHODS

This analysis is intended to juxtapose the basic factors that contribute to a change in suture strength and the possible failure of surgical sutures, which may affect the wound healing process and increase the risk of postoperative complications.

RESULTS

The preliminary search criteria used in the databases included keywords such as: "strength of suture materials", "strength of surgical sutures", "surgical knot strength". Five key articles were ultimately selected from a pool of 336 articles first identified based on these search criteria. Next, a meta-analysis of the literature data was performed, taking into account factors such as the type of suture materials used, biological conditions and model conditions used in research, having a significant impact on the mechanical properties of surgical sutures.

CONCLUSIONS

This comparison revealed considerable variations in the suture strength between different sutures of the same size, it also demonstrated that the decrease in suture strength strongly depends on the finished suture and the thread type.

Growth performance, carcass composition, leg bones, and digestive system characteristics in Pekin duck broilers fed a diet diluted with whole wheat grain

A total of 270 Pekin ducks were reared for 49 d to determine the effect of feeding a diluted complete commercial wheat grain diet on live weight, feed intake and conversion, carcass, leg bone, and digestive system traits. Different feeding regimes had a significant effect on the body weight of the ducks aged 35 d and the feed conversion ratio in the period between days 22 and 35 of rearing. Dilution of a complete commercial diet with whole wheat grain had no significant influence on the final live weight (day 49), feed intake, and feed conversion ratio during the entire rearing period. Ducks fed a diet with whole wheat grain had a significantly higher dressing percentage after higher percentage of pectoral muscles, skin with subcutaneous fat, abdominal fat, as well as a significantly lower percentage of carcass remainders at the age of 49 d. Dilution of a complete commercial diet with whole wheat grain had no impact on the length of the respective intestinal sections nor on the weight and percentage share of gizzard, liver, heart, and spleen. However, it significantly lowered the fracture strength of the tibiotarsus, and decreased some dimensions of the femur and tibiotarsus.

Relationship between the mineral content of human trabecular bone and selected parameters determined from fatigue test at stepwise-increasing amplitude

PURPOSE

The study aimed to investigate a relationship between the mineral content of human trabecular bone and parameters determined from compression fatigue tests at stepwise-increasing amplitude.

METHODS

Mineral content of trabecular bone was estimated comparing density and bone mineral density values. The relationship between the ash density, bone mineral density and factors obtained from fatigue test: fatigue life, cumulative elastic energy and cumulative energy of dissipation was determined.

RESULTS

The results from the measurements of ash density and bone mineral density show good correlation with the fatigue test results. The relationship was estimated based on the correlation coefficient R within 0.74-0.79 for the particular pairs of factors.

CONCLUSIONS

The study shows that the ash density and the bone mineral density are good predictors to estimate the fatigue life of trabecular bone. The study also validates the applicability of the tests at stepwise-increasing amplitude in determining the mechanical properties of trabecular bone.

Radiological and biomechanical analysis of humeral fractures occurring during arm wrestling

Background

Arm wrestling has recently become one of the most popular sports among young people, mainly due to its simplicity and spectacularity. Yet, unfortunately it is also injury prone. The aim of the study was to perform a biomechanical analysis of the forces which act during arm wrestling, as well as to explain the mechanism of the occurrence of humeral fractures of a similar topology as observed on X-rays.

Material/Methods

During the period 2001 to 2008 nine cases of humeral fractures resulting from arm wrestling were consulted and treated at the Clinic. The assessment of the limb condition included an interview and the examination of the fractured extremity. All the patients underwent surgical treatment, using the method of open reduction and internal fixation. The virtual dynamic model of the upper limb was established on the basis of a series of computer tomography scans of the bone, and literature data. The biomechanical analysis was carried out using the Finite Elements Method (FEM).

Results

There were five cases of the 12-B1 type in the AO Classification with butterfly fragments in five cases, and four of the 12-A1 type without the butterfly fragment. The maximum bone stress resulting from torsional loading which occurs during arm wrestling amounted to 60 MPa and was located 115 mm above the elbow on the medial - posterior side of the humeral.

Conclusions

The strength analysis carried out during arm wrestling revealed that the forces of the acting muscles significantly exert stresses within the distal third of the humeral.

The relationship between trabecular bone structure modeling methods and the elastic modulus as calculated by FEM

Trabecular bone cores were collected from the femoral head at the time of surgery (hip arthroplasty). Investigated were 42 specimens, from patients with osteoporosis and coxarthrosis. The cores were scanned used computer microtomography (microCT) system at an isotropic spatial resolution of 36 microns. Image stacks were converted to finite element models via a bone voxel-to-element algorithm. The apparent modulus was calculated based on the assumptions that for the elastic properties, E = 10 MPa and ν = 0.3. The compressive deformation as calculated by finite elements (FE) analysis was 0.8%. The models were coarsened to effectively change the resolution or voxel size (from 72 microns to 288 microns or from 72 microns to 1080 microns). The aim of our study is to determine how an increase in the distance between scans changes the elastic properties as calculated by FE models. We tried to find a border value voxel size at which the module values were possible to calculate. As the voxel size increased, the mean voxel volume increased and the FEA-derived apparent modulus decreased. The slope of voxel size versus modulus relationship correlated with several architectural indices of trabecular bone.

Microarchitecture parameters describe bone structure and its strength better than BMD

Introduction and Hypothesis. Some papers have shown that bone mineral density (BMD) may not be accurate in predicting fracture risk. Recently microarchitecture parameters have been reported to give information on bone characteristics. The aim of this study was to find out if the values of volume, fractal dimension, and bone mineral density are correlated with bone strength. Methods. Forty-two human bone samples harvested during total hip replacement surgery were cut to cylindrical samples. The geometrical mesh of layers of bone mass obtained from microCT investigation and the volumes of each layer and fractal dimension were calculated. The finite element method was applied to calculate the compression force F causing ε = 0.8% strain. Results. There were stronger correlations for microarchitecture parameters with strength than those for bone mineral density. The values of determination coefficient R² for mean volume and force were 0.88 and 0.90 for mean fractal dimension and force, while for BMD and force the value was 0.53. The samples with bigger mean bone volume of layers and bigger mean fractal dimension of layers (more complex structure) presented higher strength. Conclusion. The volumetric and fractal dimension parameters better describe bone structure and strength than BMD.

Investigation of statistical relationships between quantities describing bone architecture, its fractal dimensions and mechanical properties

The paper presents linear, logarithmic and exponential regression tabecular bone indices, fractal dimensions and strength. The analysis of the above parameters was supported by determining non-parametric correlation coefficients: Spearman's ρ, gamma and Kendall's τ. The principal components' analysis (PCA) was also performed in order to reduce the number of indices describing the variance in the data set. The analysis showed the most independent indices: lacunarity (λm, λmin, λmax), BMD, Conn.D., SMI, DA, ρA and age.

Relationships between structure, density and strength of human trabecular bone

The article deals with the examination of the relationships between density, structure parameters and strength of human trabecular bone. The tests were carried out on the samples taken from osteoporotic and coxarthrotic human femoral heads. The samples cylindrical in shape had the diameters of 10 mm and the height of 8.5 mm. During the tests with microCT scanner the parameters of a sample structure were measured. Bone mineral density (BMD) was measured as well. The samples were subjected to compression in order to assess the ultimate compression strength sigma(c). The relationships between two-element combinations (BMD and one of the structure parameters) and the compression strength of the samples have been studied. The consistency of the results for multiple regression and response surface regression was estimated based on the correlation coefficient R. For the examined pairs of parameters, the value R increased in the range of 7-30% in comparison with the case where for the strength description only BMD was used. Additionally, the authors' own models of two-variable regression was calculated. The comparison of the results obtained for all models of regression based on the coefficient E proved the consistency of these results.

Impact of injury on changes in biomechanical loads in human lumbar spine

Implementation of new spine stabilisation systems should be preceded by the analysis of the behaviour of healthy and damaged spine under laboratory conditions. Research was performed on two-part and three-part segments without damage and with disc damage in the two-part segment, and with a wedge cut in the vertebra in the three-part segment. In the two-part segment, a relative power necessary for inducing extension-compression in the damaged segment is twice as high as in the damaged three-part segment. In the damaged two-part segment, the motion in the sagittal plane needs a relative power being more than twice as high as in the damaged three-part segment. Yet absolute average values of powers examined in the two-part and three-part segment systems in the undamaged spine for all types of motion were similar, with slight advantage of the two-part segment system. Basic two-part segment of the spine motion system is its most stable functional part.

Transpedicular plate fixator as effective system of spine stabilisation: biomechanical characteristics

INTRODUCTION

Zespol fixator, which was created in Poland by Ramatowski and Granowski, has an angular stable connection of screws and plate. These properties of this plate fixator, that is effective and not an expensive system of osteosynthesis of shaft of long bone widely used in Poland, impelled us to adapt it as a transpedicular plate fixator of spine.

AIM

The aim of our in vitro study was to measure loads acting on spine stabilized by transpedicular plate fixator and to determine if its stability is comparable with uninjured spine. We also hypothesized that the spine stability with examined fixator had similar properties as spine fixators constructed with screws and rods.

MATERIALS AND METHODS

We tested its biomechanical properties and compared it with a CD device by using specimens of four human spines. Each spine with damage induced in laboratory conditions was stabilised by one of those stabilisers in one (L4-L5) or two (Th12-L2) motion segments and subsequently were subject to load. The spines without and with one of transpedicular stabilization were subject to an unsymmetrical shift of +3/-4 mm for extension-compression and symmetrical shift for bending, in the frontal plane (+0.14/-0.14 rad) and the sagittal plane (+0.11/-0.11 rad), respectively.

RESULTS

Loads during extension-compression and bending in the sagittal plane were similar to the uninjured spine for short stabilization by using both stabilizers and amounted to 92.3 and 98.26%, respectively, of the load range sums of healthy spines. For long stabilization these loads amounted to 93.2 and 84.4%, respectively. Only following short and long stabilization for both devices in case of bending in the frontal plane the increase in loads up to 144.2 and 163.3% of the range sums of uninjured spines was achieved.

CONCLUSION

It corroborates the fact that the application of the modified Zespol device for spine stabilisation provides the possibility of restoring its load transfer capacity similar to that in the healthy spine and comparable with the CD device.

Analysis of chosen strength factors of spine and spine-fixator set

The paper presents chosen results of research on the lumbar-chest part of spine and the spine-fixator complex. Spines were gathered from cadavers. Both damaged and undamaged spines with and without fixator were investigated. Two types of fixator were used: a CD and a modified Zespol fixator (our idea)--marked as P. In the research, compression/distraction forces were applied. The analysis is based on the results of comparative calculation: load range, hysteresis loop area and neutral zone stiffness.