Defect Size Research Articles

Early signs of osteoarthritis in differing rat osteochondral defects.

Preclinical models of osteochondral defects (OCDs) are fundamental test beds to evaluate treatment modalities before clinical translation. To increase the rigor and reproducibility of translational science for a robust "go or no-go," we evaluated disease progression and pain phenotypes within the whole joint for two OCD rat models with same defect size (1.5x 0.8 mm) placed either in the trochlea or medial condyle of femur. Remarkably, we only found subtle transitory changes to gaits of rats with trochlear defect without any discernible effect to allodynia. At 8-weeks post-surgery, anatomical evaluations of joint showed early signs of osteoarthritis with EPIC-microCT. For the trochlear defect, cartilage attenuation was increased in trochlear, medial, and lateral compartments of the femur. For condylar defect, increased cartilage attenuation was isolated to the medial condyle of the femur. Further, the medial ossicle showed signs of deterioration as indicated with decreased bone mineral density and increased bone surface area to volume ratio. Thus, OCD in a weight-bearing region of the femur gave rise to more advanced osteoarthritis phenotype within a unilateral joint compartment. Subchondral bone remodeling was evident in both models without any indication of closure of the articular cartilage surface. We conclude that rat OCD, placed in the trochlear or condylar region of the femur, leads to differing severity of osteoarthritis progression. As found herein, repair of the defect with fibrous tissue and subchondral bone is insufficient to alleviate onset of osteoarthritis. Future therapies using rat OCD model should address joint osteoarthritis in addition to repair itself.

Effects of sintering temperatures on the thermal conductivity and microstructural evolution of yttrium hydride monoliths by spark plasma sintering

In this study, YHx (where x represents the H/Y ratio) monoliths were fabricated using Spark Plasma Sintering (SPS), employing yttrium hydride powder as the raw material. The effects of different sintering temperatures (800 °C∼1200 °C) on the thermal conductivity and microstructural evolution of the YHx monoliths, including porosity, grain size, precipitated phases, and internal defects, were investigated. The results indicate that the sintering temperature exerts a significant influence on thermal conductivity and microstructural evolution. Notably, the thermal conductivity of these samples initially increases with rising sintering temperature, but subsequently decreases under identical testing conditions. This phenomenon is primarily attributed to the effects of porosity and precipitate phase. Furthermore, the presence of twin crystals also contributes to the reduction in thermal conductivity. The procedures provide an initial framework for understanding the relationship between thermal conductivity and the evolution of microstructure.

Transcatheter closure of atrial septal defect (ASD) in adult and paediatric population without transoesophageal echocardiography/general anaesthesia

Abstract Background Transcatheter device closure is the preferred therapeutic option for ostium secundum atrial septal defect(OS-ASD). Standard practice is to perform it under transoesophageal echocardiography(TEE) guidance. However, TEE is performed under general anaesthesia (GA) and leads to increases in cost, procedural duration, ICU stay, total hospital stays, risk of oesophageal injury and complications of GA. Transthoracic echocardiography(TTE) is an excellent alternative and prior studies have shown it to be a safe alternative in paediatric population. In current study we analysed safety and efficacy of TTE-guided device closure of OS-ASD in all comer population irrespective of age, weight, defect size. Methods The study enrolled all patients who underwent device closure of OS-ASD between March 2017 and December 2023. All procedures were performed under LA for adults and conscious sedation for children. The device was placed under fluoroscopy guidance and position were confirmed on TTE. Procedural success, device, defect size ratio, procedural time, fluoroscopy time, complications, intensive care unit/hospital stay duration were analysed and compared with our own experience of 125 patients with TEE-guided closures before switching to complete TTE-guided procedure(before 2017). Results 340 patients underwent TTE-guided device closure of ASD. Procedure success was 97.4% with acceptable risk of major complications. Three(0.8%) had embolization into pulmonary artery, successfully operated surgically. Two had tamponade requiring drainage. In 9 patients, device could not be deployed despite multiple attempts and approaches. All of these had defect size of > 34mm and deficient IVC rim along with shorter (other than aortic) rim. Findings were compared with our own previous experience of TOE guided closure (practised before 2017). Compared to TOE group, TTE group had significantly lower total procedural duration (75±4 vs. 28 ±1 min; p < 0.01), intensive care unit stay (24±10 vs. 10.5±1 h; p < 0.01), and hospital (48±12 vs. 25.5±4h; p < 0.01) stay duration. Fluoroscopic time was similar in both. There was no mortality in either group. Major complications were comparable, TTE-guided group had less post-procedure complications of vomiting and headache. Additional findings of less pre-procedure fasting duration and early commencement of post procedure oral intake were noted in TTE group. Conclusion TTE-guided device closure of OS-ASD is a safe and feasible in all-comer population in experienced hands. It can definitely negate the use of TEE except in very poor echo window. The added advantages include utilization of physiological variations in PV/LV pressure during cough, Valsalva manoeuvres in awake patients. It definitely reduces the procedural duration, cost of procedure and dependence on GA and trained transoesophageal echocardiographer.

Applicability evaluation technology for steel small diameter pipes containing external surface corrosion defects

With the continuous operation of oil and gas stations and petrochemical equipment, it has been found that steel small bore pipelines have different degrees of corrosion defects, which have led to pipeline cracking and medium leakage, and have increasingly attracted great attention of their oil and gas and chemical enterprises. In order to ensure the safe operation of the small diameter pipes with external surface corrosion defects, the influence law of the size of corrosion defects on the bearing capacity of the small diameter pipes were studied by finite element analysis and test simulation method, and the damage mechanism and failure form were analyzed, and the failure pressure prediction formula of the small diameter pipes with defects was fitted. It provides technical guidance for the applicability evaluation of corrosion-containing steel small diameter pipes in oil and gas chemical stations or installations.

Safety and efficacy of perventricular device closure of ventricular septal defects in children

Abstract Objectives To evaluate safety and efficacy of perventricular device closure techniques for the closure of ventricular septal defects (VSD) in children in United Arab Emirates. Methods In the year 2023-24, 13 children underwent per-ventricular device closures of VSD under the guidance of transesophageal echocardiography without cardiopulmonary bypass(CPB). The mean age at operation was 3.76 years (range 3 months-14 years). The ventricular septal defect sizes ranged from 2.7-6 mm. The device sizes ranged from 5-12mm. All patients except two required symmetrical device. Eight defects were peri membranous, 3 were sub-aortic and 2 were muscular. Ventricular septal defect occlusion device (Memoport, Beijing, China) were used through a 3-cm skin incision in the lower third of the sternum. Results All patients underwent VSD device closure successfully. The mean procedural duration was 42 minutes. None of the patients required CPB. The mean ventilation time and ICU stay was 3 hrs. and 24 hrs. respectively. None of the patients required inotropic support or blood transfusions. There were no residual shunt (except small shunt through the device), arrhythmias including heart block post operatively. At follow up, (3 months-7 months) there were no residual shunts, conduction disturbances, device dislodgement or major aortic or tricuspid valve complications. There was no mortality. Conclusions Perventricular device closure of VSD is highly successful, less invasive, safe and effective. It is associated with quick recovery, short length of stay and better cosmetic incision. Moreover, it avoids CPB.

Study on the uniaxial tensile mechanical behavior of two-dimensional single-crystal aluminum nitride

Abstract To investigate the tensile behavior and mechanical properties of single-crystal aluminum nitride (AlN) at the microscopic level, molecular dynamics simulations were used to study the effects of crystal orientation, strain rate, environmental temperature, and hole defect size on fracture strength, fracture mechanism, and potential energy during uniaxial tensile. The results show that the tensile strength of AlN in the [100] crystal direction is stronger. The anisotropic behavior characteristics of Al-N bonds fracture mechanism, crack growth rate, and cracking degree are significant when stretched along the [100], [010], and [110] crystal directions. Under high temperature condition, the lattice structure undergoes changes, causing grain boundaries to move and slip. This facilitates the breaking of bonds, leading to a decrease in tensile strength and a reduction in stored potential energy. Hole defects cause more lattice damage, reducing the energy required for Al-N bonds breakage and facilitating the propagation of microcracks. Additionally, it was found that the strain rate affects the stress-strain behavior of the model. An increase in strain rate leads to an increase in breaking stress, and the rapid deformation of AlN results in more energy being stored in the lattice in the form of potential energy. Therefore, the tensile strength and potential energy are improved.

Drainage of middle cranial fossa epidural abscess through mastoidectomy: Our experience and review of the literature

Background: Otitis media (OM) can uncommonly lead to intracranial complications. Epidural abscesses represent a large proportion of cases; however, literature regarding the optimal surgical management of otogenic epidural abscesses is sparse. Favorably located epidural abscesses may be amenable to drainage through a transmastoid approach because the tegmen mastoideum lies immediately inferior to the middle cranial fossa (MCF). Case Description: We report 3 pediatric patients with OM complicated by epidural abscesses of the MCF. The ages ranged from 3 to 6 years old, with 2 females and 1 male. All 3 patients had acute mastoiditis with an abscess of the MCF ranging from 1.6 cm to 6.3 cm at the largest dimension. All patients underwent canal wall-up mastoidectomy with the evacuation of the MCF abscess through a small window, 0.7 × 0.7 cm or less, created in the tegmen mastoideum. All patients were successfully treated through this approach and had complete resolution of their infection on follow-up imaging. There were no postoperative temporal lobe encephaloceles. Conclusion: This is one of the few descriptions of the treatment of an otogenic epidural abscess of the MCF through a transmastoid approach. Collaboration with neurosurgery is vital because their familiarity with the intracranial space helped to guide the accurate direction of dissection. This highlights the importance of a multidisciplinary approach in the treatment of epidural intracranial abscess of the MCF through this approach. The risk of postoperative temporal lobe encephalocele was minimized due to the small tegmen defect size.

Management of Frontal Bone Exposure Following Paramedian Forehead Flap for Nasal Reconstruction.

The paramedian forehead flap is renowned for its versatility and can cover a wide range of nasal defect sizes. Most of the literature discussing outcomes of paramedian forehead flap reconstructions focuses on morbidity at the recipient site. Frontal bone exposure resulting from the use of the paramedian forehead flap is a rare but possible complication, especially when periosteum overlying the bone is damaged during surgery or during healing by secondary intention due to desiccation. In this case, a 53-year-old female underwent nasal reconstruction with a paramedian forehead flap for an extensive nasal defect after Mohs surgery and resection of residual basal cell carcinoma. She missed her postoperative follow-up visit, and her frontal bone was noted to be exposed before the division of the pedicle procedure. During the division of the pedicle, the frontal bone was burred, and a bilayer dermal regeneration matrix was applied. She underwent a split-thickness skin grafting from her thigh at 4 weeks. The graft take was 100%, and wound closure was achieved with an acceptable cosmetic outcome. The successful resolution of the complication through innovative surgical interventions highlights the importance of adaptive surgical strategies and thorough postoperative care, aiming to contribute to the existing body of knowledge and improve future clinical practices in reconstructive surgery.

Detection of delamination using laser-generated Lamb waves with improved wavenumber analysis

Abstract Delamination is a typical failure mode in multilayered materials, which may potentially threaten the safety and reliability of the materials if not detected promptly. This paper proposes a novel quantitative detection method for delamination in multilayered materials based on laser-generated Lamb waves with improved wavenumber analysis. First, a three-dimensional(3D) finite element model is established to simulate the interaction between delamination and laser-generated Lamb waves. The propagation characteristics of Lamb waves in multilayered materials without defects and with delamination of three different shapes, i.e., rectangular, circular and triangular are analyzed. And the mechanism that delamination can lead to the appearance of scattered wave and new wavenumber components is investigated, facilitating the quantitative detection of delamination. Then, an improved wavenumber analysis method for quantitative detection of delamination is proposed. The new wavenumber components caused by delamination are extracted by broadband adaptive wavenumber filtering to reduce imaging interference and artifacts caused by irrelevant components, and the spatial wavenumber spectrum is obtained by fast broadband local wavenumber estimation algorithm to enhance the delamination imaging accuracy and spatial resolution. The experimental results indicate that, across various experimental scenarios, the proposed method achieves superior imaging precision compared to traditional wavenumber filtering or local wavenumber estimation methods, and can quantitatively identify delamination defects of various shapes and sizes.

Fatigue Scattering Analytics and Prediction of SS 316L Fabricated by Laser Powder Bed Fusion

Abstract Laser powder bed fusion (LPBF) is an enabling process manufacture of complex metal components. However, LPBF is prone to generate geometrical defects (e.g., porosity, lack of fusion), which causes a significant fatigue scattering. However, LPBF fatigue scattering data and analysis in the literature are not only sparse and limited to tension-compression mode but also inconsistent. This article presents a robust high-frequency fatigue testing method to construct stress-cycle curves of SS 316L to understand the scattering nature and predict the scattering pattern. A series of bending fatigue tests are performed at different stress amplitudes. Two different runout criteria are used to investigate fatigue life, fatigue limits, and scattering. The endurance limit reaches around 300 MPa for the defect size distribution at the selected process space. The defect size-based fatigue limit model is found to underestimate the endurance limit by about 30 MPa when comparing with the experimental data. Fatigue scattering is further calculated by using 95% prediction intervals, showing that low fatigue scattering is present at high stresses while a large variation of fatigue life occurs at stresses near the knee point.

Unified analytical theory of nonlinear optical diffraction by nonlinear gratings

When a pump laser shines upon a periodically poled lithium niobate (LN) thin plate nonlinear grating, second-harmonic generation (SHG) and its nonlinear diffraction occurs, with the nonlinear Raman–Nath diffraction (NRND), nonlinear Bragg diffraction (NBD), and nonlinear Cerenkov radiation (NCR) being several prominent examples. In this work we build and present a unified analytical theory to solve SHG for the NRND, NCR, and NBD processes from LN domains, domain walls, and defects. We find that the critical physical entity that governs the nonlinear diffraction is the effective nonlinear coefficient for each Fourier wave component. The analytical theory has a great generality and applicability scope. It allows us to retrieve and analyze everything about the dependence of SHG nonlinear diffraction on a series of physical and geometrical parameters such as the pump laser intensity, polarization, incidence polar and azimuthal angles, the LN thin plate thickness and its crystalline orientation, LN domain size and pitch, domain wall thickness and crystalline configuration, defect size and crystalline configuration, and the SHG diffraction beam angle and polarization. The analytical theory also enables us to analyze deeply the similarities and differences of the three nonlinear diffraction processes NRND, NCR, and NBD, build a smooth and broad connection bridge among these three processes, and construct a unified physical picture to understand, describe, and exploit these three processes of seemingly big difference. Besides, the analytical theory can be applicable to handle nonlinear diffraction by domains, domain walls, and defects in other more complicated 2D and 3D nonlinear gratings made from LN and other nonlinear crystals. Finally, the analytical theory can help to build a bridge connecting the extrinsic SHG nonlinear diffraction properties with the intrinsic domain poling and inversion material and physical properties of LN and other nonlinear crystals and explore novel nonlinear optical devices and technologies.

A novel wafer defocus measurement method for spot-scanning imaging system using laser triangulation

Abstract For spot scanning dark-field scattering technology, the defocus caused by the change in wafer surface height decreases the defect detection rate and size measurement repeatability. The demand for accurately and rapidly measuring the wafer surface height online is becoming increasingly urgent. The defect detection system integrates scattering, reflection, film thickness, and topography defect detection channels. The integration of laser-triangulation-based defocus measurement into the bright-field optical path is proposed. The laser beam is directed onto the surface of the wafer, and the reflected light is transmitted through a lens onto the photosensitive surface of a four-quadrant detector. This detector captures both the strength and position of the reflected signal simultaneously. In this paper, a triangulation-modified model is established to obtain the height of each inspection spot on the wafer surface through the position signal of the reflected image. When the signal-to-noise ratio of the simulated reflection image position is 20 dB, the signal-to-noise ratio of the height measurement resolved by the triangulation-modified model is 41 dB, and the measurement error is less than 0.2 μm, indicating that the model has a noise suppression effect. The spot-scanning imaging system is established, and the height measurement results of the triangulation measurement model are verified using a laser interferometer. Within the travel range of 69 μm, the system has a measurement accuracy better than ±1 μm and a measurement repeatability better than ±0.2 μm, which meet the measurement requirements of the spot-scanning imaging system. The system is utilized for defect detection and defocus measurement of the wafer surface, along with the motion mechanism, to accurately and rapidly obtain the height distribution of the wafer surface.

A Candy Defect Detection Method Based on StyleGAN2 and Improved YOLOv7 for Imbalanced Data.

Quality management in the candy industry is a vital part of food quality management. Defective candies significantly affect subsequent packaging and consumption, impacting the efficiency of candy manufacturers and the consumer experience. However, challenges exist in candy defect detection on food production lines due to the small size of the targets and defects, as well as the difficulty of batch sampling defects from automated production lines. A high-precision candy defect detection method based on deep learning is proposed in this paper. Initially, pseudo-defective candy images are generated based on Style Generative Adversarial Network-v2 (StyleGAN2), thereby enhancing the authenticity of these synthetic defect images. Following the separation of the background based on the color characteristics of the defective candies on the conveyor belt, a GAN is utilized for negative sample data enhancement. This effectively reduces the impact of data imbalance between complete and defective candies on the model's detection performance. Secondly, considering the challenges brought by the small size and random shape of candy defects to target detection, the efficient target detection method YOLOv7 is improved. The Spatial Pyramid Pooling Fast Cross Stage Partial Connection (SPPFCSPC) module, the C3C2 module, and the global attention mechanism are introduced to enhance feature extraction precision. The improved model achieves a 3.0% increase in recognition accuracy and a 3.7% increase in recall rate while supporting real-time recognition scenery. This method not only enhances the efficiency of food quality management but also promotes the application of computer vision and deep learning in industrial production.

Fatigue behavior of additively manufactured 316L stainless steel: Competition between the effects of defects and microstructure

Laser Powder Bed Fusion (LPBF) process, is becoming more and more widespread in industry. The possibilities of microstructural control offered by this process are an opportunity to study the contribution of the different length scales of microstructure to the fatigue behavior. This paper is devoted to the understanding of this fatigue behavior resulting from the interactions between the process induced defects and the different polycrystal length scales. Two distinct defect − microstructure competition regimes have been identified. The first concerns microstructures containing large Lack of Fusion (LoF) defects. These LoFs drastically reduce the fatigue life, while microstructure has no influence on the fatigue strength. The second regime concerns microstructures containing small defects. A limited effect of the polycrystalline microstructure was revealed. Furthermore, this paper demonstrates that the ratio between damage initiation defect size and grain size, used in literature to describe the defect and microstructure sensitivity of fatigue strength, is not applicable over a wide range of defects and microstructures, such as obtained by additive manufacturing processes. Finally, the comparison between the fatigue behavior of different microstructure and defect features shows that producing a finer microstructure improves fatigue strength despite the presence of a significant defect population.

Dynamic Modeling of Angular Contact Ball Bearing with Local Defects under EHL Considering Impact Force

In order to analyze the operating status of angular contact ball bearings(ACBBs) with local defects in more detail, a dynamic model of ACBB with local defects considering impact force under elastohydrodynamic lubrication conditions is proposed. Firstly, an elastohydrodynamic lubrication model for defective bearings considering spin is established, the film thickness and film stiffness of the defective bearings are calculated, and then time-varying displacement excitation model and time-varying stiffness model for local defects in angular contact ball bearings is presented. Based on this, an instantaneous impact force function related to defect size and bearing speed is established. Secondly, based on Hertz contact theory and impact force function, a dynamic calculation method for ACBBs with local defects on the outer ring is proposed. Finally, the vibration characteristics of ball bearings with faults are investigated, and the influence of different parameters on the dynamic response of the bearings is analyzed. The calculation results show that under lubrication conditions, the impact force on the vibration of the bearing is significantly weakened. With the increase of defect size and load, the frequency of bearing fault characteristics remain unchanged, but its amplitude increases. As the bearing speed increases, the characteristic frequency and amplitude of bearing faults increase.

Research on tire appearance defect detection algorithm based on efficient multi-scale convolution

Abstract Due to the large randomness of tire appearance defect size and the complex and diverse defect shapes, the existing target detection algorithm is prone to missing and misidentifying targets, the accuracy is limited, and the detection model is large, which is not conducive to deployment on embedded devices. In this paper, the efficient multi-scale convolution (EMC) mode is proposed, and the C2f-EMC module is designed on this basis, which improves the network structure of YOLOv8, improves the accuracy of tire appearance defect detection, and reduces the number of parameters in the model. EMC convolution first divides the input feature images into four parts on average and carries out multi-scale convolution with convolution cores of 1×1, 3×3, 5×5 and 7×7 sizes respectively. Then, the obtained results are stacked, and cross-channel feature fusion is realized by point-by-point convolution. After determining the network structure of C2f-EMC, the best improvement position of C2f-EMC module is determined through comparative experiments. Experiments show that after the above improvements, the parameter number of the model is reduced by 4.85%, the calculation amount by 2.82%, the model size by 4.44%, the recall rate by 2.8%, the mAP50 by 1.0%, the mAP50-95 by 1.3%, and the F1 by 2%. The defect detection task can be completed more accurately and the model size requirements of embedded devices can be better met.

Fatigue life prediction of film-cooling Hole specimens with initial damage

This study investigates a Nickel-based single crystal (SX) superalloy with femtosecond laser-drilled film-cooling holes (FCHs) under varying temperatures (room temperature, 850 °C, and 980 °C), employing a novel framework for predicting fatigue life based on initial manufacturing damage quantification. For all tested anisotropic SX superalloy specimens (including smooth and FCH specimens), the initial damage state is characterized as an equivalent initial flaw size (EIFS), and an EIFS calculation model considering stress concentration is established. Subsequently, the fatigue crack paths and microstructural characteristics of the FCH specimens at different temperatures are analyzed, elucidating crack initiation mechanisms and propagation patterns. A novel incremental plasticity J-integral driving force for fatigue crack propagation is introduced. By incorporating the closure effect of small crack propagation and employing Markov Chain Monte Carlo simulations for determining crack growth rate probabilities, a more accurate expression for the crack growth rate in relation to ΔJfat − ΔJth is derived. This expression comprehensively captures crack patterns on crystallographic planes and Type I mixed mode behavior. Finally, the total fatigue life of the FCH structures, featuring a threefold dispersion zone in both room and high-temperature environments, is predicted through experimental observations and description of crack growth rates. The predicted outcomes significantly outperform those of the conventional life prediction models reliant on crystal plasticity theory.

Effects of Build Direction and Heat Treatment on the Defect Characterization and Fatigue Properties of Laser Powder Bed Fusion Ti6Al4V

Laser powder bed fusion (LPBF) is one of the high-precision additive manufacturing techniques for producing complex 3D components. It is well known that defects appear in additive-manufactured parts, and they deeply affect the fatigue properties; even heat treatment is performed after printing. In order to meet the safe-life design requirements of additive-manufactured aircraft structures, the effects of build direction and heat treatment on defects and fatigue properties need to be quantified. Hence, Ti6Al4V alloy samples with different build directions were designed and printed by LPBF. X-ray computed tomography was used to quantitatively analyze the defect size, the sphericity, and the defect orientation. And their effects on fatigue properties were studied. An extended effective defect size and a defect-based fatigue anisotropy evaluation process are proposed to qualify the effects of the defect size, sphericity, and defect orientation. It is shown that the build direction can affect the porosity distribution and maximum defect size, while the annealing treatment can cause the coalescence of small defects and higher porosity. The defect orientation exhibited a fluctuating trend of 0°–90°–0°–90°–0° as the volume increased. The elongated lack of fusion defects related to the build direction was the main crack source and could lead to fatigue anisotropy of LPBF Ti6Al4V.

Association of Extraosseous Arterial Diameter With Talar Dome Osteochondral Lesions.

Etiology of osteochondral lesions of the talus (OLT) is multifactorial and may develop from trauma, genetics, or hypovascularity. The talar dome is supplied by the posterior tibial artery (PTA) and, to a lesser degree, the sinus tarsi artery (STA). The role of talar dome hypovascularity on OLT remains poorly studied. We aimed to determine any relationship between the diameter of PTA (dPTA) and STA (dSTA) and the incidence and characteristics of talus OLT. This retrospective study included 77 patients with OLT and 77 subjects as a matched control group (age range: 30-40 years). Using magnetic resonance imaging, the dPTA was measured 1 cm above the tibial plafond, at the plafond, and at the level of medial malleolar tip. Likewise, dSTA was measured at the level of the talar neck. The area, volume, depth, localization, and surgical intervention for OLT were recorded as well. The study group had significantly smaller dPTA at all 3 levels (1.05 ± 0.22 mm, 0.99 ± 0.18 mm, 0.98 ± 0.31 mm, proximal to distal, respectively) compared with controls (1.25 ± 0.23 mm, 1.20 ± 0.22 mm, 1.14 ± 0.18 mm, respectively) (P < .001). The dSTA was also significantly smaller in the study group compared with the control group (0.5 ± 0.11 mm vs 0.57 ± 0.08 mm, respectively; P = .001). The mean dPTA (of all 3 levels) cutoff value for predicting the occurrence of OLT was 1.1 mm with 74% sensitivity and 75% specificity. A significant inverse correlation was observed between OLT area and arterial diameters (P < .001). Smaller luminal dPTA and dSTA appear to be associated with higher incidence of OLT, with defect size inversely correlated to arterial diameter.

Results of innervated digital artery perforator flap and direct-flow homodigital flap application in fingertip soft tissue amputations

ObjectiveThe purpose of this study is to compare the results of the innervated digital artery perforator (IDAP) flap and the direct-flow homodigital flap as reconstruction methods for fingertip soft tissue amputations. This issue is important in hand surgery, and we aim to identify the method that provides the best functional and cosmetic outcomes.MethodsBetween 2020 and 2022, 32 patients with fingertip amputations were reconstructed by the same surgeon using two different methods. The patients were retrospectively divided into two groups: those who underwent IDAP (n = 14) and those who had a direct-flow homodigital flap (n = 18). We compared the groups in terms of defect size, cold intolerance, venous congestion, Sollerman hand function test scores, Seddon sensory test scores, and follow-up periods, as well as flap viability, flexion contracture, and static two-point discrimination (s2PD).ResultsOf the 32 patients (26 men, 6 females; age: mean 28.72 ± 11.5 years), the injuries were caused by different mechanisms, including sharp (57.1% IDAP), crush (75% IDAP) and entanglement (66.7% homodigital). The average area of tissue loss was approximately 2.70 ± 1.37 cm², while the average s2PD measurement was approximately 4.94 ± 1.04 mm. Postoperatively, the Seddon sensory test results for the homodigital flap group were S4 (61.5%), S3 (23.1%), S3+ (7.7%), and S2 (7.7%), compared to the IDAP group, which showed S4 (57.9%), S3+ (21.1%), and S3 (21.1%). Complications occurred in five patients, though no flap loss or revision was required. The postoperative mean Sollerman hand function scores were higher for the homodigital group than for the IDAP group, with values of 75 ± 2.64 and 73 ± 3.34, respectively. Although not statistically significant, the results numerically suggest that the IDAP flap is better in terms of sensory recovery and hand function compared to the homodigital flap (p > 0.05).ConclusionsThis is the first investigation to compare direct-flow flaps with IDAP. The average follow-up period for patients who underwent homodigital surgery was also shorter than that of the IDAP group. Furthermore, the mean postoperative two-point discrimination and postoperative Sollerman function score were higher in patients who had homodigital surgery.