Fracture Fragments Research Articles

Evaluation of an anthropometric head surrogate exposed to chisel-nosed fragment simulating projectile impact

Fragment-induced penetrating injuries pose a significant threat in modern combat. Explosions from explosive devices generate metallic fragments that can lethally penetrate various body regions, with the head being particularly most vulnerable to fatality in terms of penetration. Hence, understanding the head’s response to fragment impact is crucial. To this end, this study investigated the ballistic response of an anatomically accurate anthropometric head surrogate to fragment impact. The head surrogate comprised simulants for the three major layers of the head (skin, skull, and brain). Using a pneumatic gas gun, we impacted chisel-nosed fragment simulating projectiles (FSPs) of 1.10-g and 2.79-g on the head surrogate. We analyzed the ballistic response of the head surrogate in terms of ballistic limit velocities (V50), energy densities (E50/A), and failure mechanisms in each layer. The results indicated sensitivity to the FSP size. The 1.10-g FSP had a ∼41% higher V50 and a ∼63% higher E50/A compared to the 2.79-g FSP. Additionally, each head surrogate layer exhibited distinct failure mechanisms. The skin simulant failed due to a combination of shearing and elastic hole enlargement, forming a cavity smaller than the size of the FSP. The skull simulant fractured, creating a cavity at the entry point matching the FSP size. The brain simulant failure involved shearing of the cavity and penetration of fractured skull fragments. We also observed no significant difference in response when introducing a flexible neck attachment on which the head surrogate was mounted. Furthermore, comparisons of an anthropometric (close-shape) head surrogate with a simplified open-shaped head surrogate revealed the minimal influence of the head curvature on the response due to the localized nature of fragment penetration. These findings provide a comprehensive understanding of the head surrogate’s mechanical response to fragment impact. The insights from this work hold significant value in the assessment of penetrating head injury, especially against small fragments. The results can be applied in modern warhead design and forensic investigations.

Acute irreducible anterior shoulder dislocation due to interposition of the subscapularis muscle and the lesser tuberosity: a case report.

Efforts to reduce an anterior shoulder dislocation can fail due to numerous mechanical obstructions caused by soft tissue interposition (long head of the biceps, rotator cuff muscles, labrum, musculocutaneous nerve) and/or bony elements (displaced fragment of a greater tuberosity or glenoid fracture, bone impaction such as a Hill-Sachs lesion fixed on the glenoid rim, a bony Bankart lesion). Herein, we report the case of a 35-year-old man who sustained an anterior shoulder fracture-dislocation of his left shoulder after a fall. Despite a postreduction radiological examination that appeared misleadingly reassuring, subtle signs of persistent subluxation raised concerns. A computed tomography (CT) scan revealed subscapularis muscle entrapment along with avulsion of its bony insertion from the lesser tuberosity of the humerus, and a comminuted avulsion fracture of the greater tuberosity of the humerus. The patient underwent surgery using a deltopectoral approach. This involved releasing the entrapped subscapularis muscle and fixing the two fractured fragments. The lesser tuberosity was reduced and secured with two cannulated screws, and the comminuted fragment of the greater tuberosity was reattached using transosseous sutures. At 12-month follow-up, the patient achieved a Constant-Murley score of 85 of 100, with limitation in internal rotation at L3 but no signs of instability or new dislocation episode. This case underscores the importance of confirming shoulder reduction on at least two orthogonal views and paying close attention to the patient's feedback about sensation in their shoulder. Additionally, it highlights the utility of CT or magnetic resonance imaging scans if doubt exists about the integrity of the reduction.

Characterize the influences of hydraulic fracturing on preventing rock burst from the stress and vibration fields

The thick and hard roof (THR) is a significant factor that induces rock burst incidents. Traditional deep-hole blasting methods struggle to effectively relieve pressure for the high-level THR on a large scale. Although the horizontal staged hydraulic fracturing technology can crack high-level rock stratas, its impact on roof fracture still needs to be clarified, and there need to be more effective methods to evaluate its pressure relief effect. This paper conducted a comparative engineering test of local hydraulic fracturing pressure relief and load reduction on the working face to address this gap. The key layer theory and mine earthquake distribution were used to identify potential hazards of rock strata and the fracturing strata. Revealed the spatial and temporal evolution rules of microseisms induced by mining work, the failure mechanism of high-energy mine earthquakes, the evolution characteristics of source mechanical parameters, and the evolution characteristics of the stope stress field. The results indicate that after fracturing microseisms during mining presented exhibit a uniform distribution of high frequency and low energy. The fracture fragmentation of the roof rock was reduced, and the range of mining disturbance was minimized. High-energy mine earthquakes induced by mining are transferred to the goaf. Simultaneously, the corner frequency and stress decrease while the rupture radius and the shear component of the failure mechanism increase. The integrity of the THR is compromised, and fracture propagates and slips along the pre-crack. The roof of the working face experiences localized pressure, with decreased periodicity and intensity, reducing the overall static load level of the coal seam under the fracturing area. The research findings serve as a valuable reference for further investigations into the mechanism and risk assessment of hydraulic fracturing in preventing and controlling rock burst.

Excellent clinical and radiological outcomes after arthroscopic reduction and double row-suture bridge for large-sized greater tuberosity fractures of the humerus.

Currently, there is limited information on the clinical outcomes of arthroscopic reduction and double-row suture bridge fixation for large greater tuberosity fractures of the proximal humerus. This study aimed to evaluate the radiological and clinical outcomes of arthroscopic reduction and double-row suture bridge fixation for these fractures, hypothesizing that arthroscopic reduction and double-row suture bridge fixation is a safe, effective and minimally invasive treatment for large greater tuberosity fractures. This retrospective study analysed patients with large greater tuberosity fractures (fracture fragment ≥30 mm in diameter) who underwent arthroscopic reduction and double-row suture bridge fixation and had a follow-up period exceeding 2 years. The anatomic reduction was confirmed by assessing the step-off on radiographs immediately after surgery, and the radiologic union time was recorded. At the final follow-up, range of motion and functional outcome scores were evaluated. Additionally, any surgery-related complications were evaluated. Fifteen patients with a mean follow-up of 57.7 ± 23.1 months were included in the study. The mean fracture fragment size was 32.5 ± 2.4 mm, with a mean displacement of 5.1 ± 1.6 mm. Immediately postsurgery, 13 of 15 patients (86.7%) had a fracture step-off of <3 mm, with an average union time of 3 months. At the final follow-up, patients demonstrated excellent outcomes, with an average forward flexion of 167 ± 9.7° and external rotation of 70 ± 16.3. Functional outcome scores showed significant improvement compared with preoperative scores (p < 0.001). No major surgery-related complications were reported. Arthroscopic reduction and double-row suture bridge fixation for large-sized greater tuberosity fractures is safe and shows good fracture reduction and excellent clinical outcomes. Therefore, this surgical method can be considered an alternative to open reduction for large greater tuberosity fractures. Level IV.

Biomechanical investigation of positive reduction in the femoral neck fracture: a finite element analysis.

Gotfried positive reduction offers an alternative strategy for femoral neck fracture (FNF) when achieving anatomical reduction is challenging. However, the biomechanical consequences of positive reduction remain unclear. The purpose of this study was to investigate the biomechanical behavior of positive reduction across different Pauwels classification, providing a reference for quantifying positive reduction in clinical practice. Three-dimensional (3D) models of FNF were established and categorized according to the Pauwels classifications (Pauwels I, II, and III), each of them contained seven models with different reduction qualities, including an anatomical reduction model, two negative reduction models, and four positive reduction models, all of which were stabilized with dynamic hip screws (DHS) and cannulated screws (CS). We investigated the maximal von-Mises stress of internal fixation and proximal femoral, femoral fragment displacement, and maximal von-Mises strain at the proximal fragment fracture site when a 2100N load was applied to the femoral head. The maximum von-Mises stress on the internal fixators in each Pauwels group was lowest in the anatomical reduction model. In the Pauwels I group, positive reduction exceeding 3mm resulted in the maximum von-Mises stress on the internal fixators surpassing that of the negative reduction model. For the Pauwels II group, positive reduction beyond 2mm led to the maximum von-Mises stress on the internal fixators exceeding that of the negative reduction model. In the Pauwels III group, positive reduction beyond 1mm caused the maximum von-Mises stress on the internal fixators to be higher than that of the negative reduction model. The maximum von-Mises strain at the fracture site of proximal femur fragment increased with positive reduction. Varus displacement increased in positive reduction models as the Pauwels angle rose, potentially exacerbating rotation deformity in Pauwels III group. Excessive positive reduction may increase the risk of FNF failure after internal fixation. From a biomechanical stability perspective, positive reduction should be limited to 3mm or below in the Pauwels I group, restricted to not exceed 2mm in the Pauwels II group, and should not exceed 1mm in the Pauwels III group. Negative reduction should be avoided in all Pauwels groups.

METHODS OF PERCUTANEOUSFIXATION OF FRAGMENTS IN SUPRACONDYLAR HUMERUS FRACTURES IN CHILDREN AND ADOLESCENTS

The aim of this study is to conduct a meta-analysis and evaluate the clinical efficacy and safety of crossed and lateral fixation of fragments in supracondylar humerus fractures in children and adolescents. Methods. A comprehensive literature search was conducted in the PubMed and EMBASE databases from 2015 to December 2023 using the following search terms: "supracondylar fractures of distal humerus in pediatric patients", "treatment", "methods of fixation", "pinning configuration", "biomechanical analysis of pin placement". According to the inclusion and exclusion criteria, the literature sources of anatomic-biomechanical and clinical studies related to the use of crossed and lateral fixation of fragments in the case of supracondylar fractures of the humerus in children and adolescents were selected and analyzed. The review was prepared in accordance with the recommendations of the "Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines." Results. A comparison of results from experimental studies investigating the degree of stabilization achieved in the crossed and lateral configurations of fixation structures reveals conflicting conclusions due to the heterogeneity of designs implemented. The principal limitation of lateral fixation is the increased risk of failure of fixation. The outcomes of clinical trials (Flynn criteria) demonstrate that both types of fracture fixation yield equivalent clinical outcomes. One disadvantage of crossed fixation is the risk of iatrogenic ulnar nerve damage, while another disadvantage is the increased complexity of the surgical technique. Conclusions. The results of anatomical and biomechanical studies indicate that cross-fixation provides more rigid fixation of fragments in supracondylar humerus fractures in children and adolescents. Nevertheless, clinical outcomes based on radiological and functional data (including Flynn's score) demonstrate no significant distinction between the two types of fixation configurations. However, they do indicate a notable risk of iatrogenic ulnar nerve damage in cross fixation, which justifies the necessity to utilise a mini-open technique in the medial fixation construct.

Influence of metal on the far-exploding surface on fragment deformation behavior under contact explosion

Metals exhibit diverse failure behavior under impact loading. In the context of fragment warheads, preformed fragments also undergo fracture and crushing behaviors when subjected to explosive loading, potentially diminishing the terminal effect and damage capability of the warhead. To address this issue, metal disks of varying impedance were applied to the far-exploding surface of the fragments, and their influence on fragment deformation behavior was examined. The experimental results revealed that when metal disks were attached to the far-exploding surface of the fragments, their fracture behavior changed, and the recovered fragments remained intact axially. Additionally, the axial length of the recovered fragments decreased as the impedance of the metal disk on the far-exploding surface increased. To elucidate the underlying mechanism of this experimental phenomenon, the variation in fragment pressure during the propagation process was calculated by employing theories of planar detonation waves and shock wave propagation in the study. The results indicate that when the impedance of the metal disks on the far-exploding surface is higher than that of the fragments, it leads to an increase in internal pressure and the formation of a compression zone within the fragments, thereby preventing fragment fracture. Conversely, lower impedance results in the formation of a tensile effect within the fragments. The theoretical and experimental results were consistent. Finally, based on the dimensional analysis, the dimensionless models were established to predict fragment deformation and internal pressure values influenced by the metal disk on the far-exploding surface.

Comparison of Decontamination-Preservation Protocols for Delayed Surgical Re-implantation of Osteoarticular Fracture Fragments

Background: To avoid discarding contaminated, devascularized osteoarticular fragments required for joint reconstruction, fragments need to be decontaminated while preserving chondrocyte viability. We hypothesized that disinfection with povidone-iodine or chlorhexidine followed by preservation using the Missouri Osteochondral Preservation System (MOPS) would allow for effective decontamination while retaining essential chondrocyte viability in osteoarticular fracture fragments for up to 14 days of shelf-stable point-of-care storage. Methods: With IACUC approval, purpose-bred hounds (n=16) were humanely euthanized for unrelated purposes and subjected to captive bolt trauma to create open distal humeral fractures. For each elbow (n=32), humerus, radius and ulna tissues were recovered such that 96 contaminated, devascularized osteoarticular fragments were randomly allocated to one treatment: Betadine (n=42): saline irrigation (1L), immersion in 10% povidone-iodine (20 min), saline irrigation; Chlorhexidine (n=42): saline irrigation, immersion in 0.002% chlorhexidine gluconate (20 min), saline irrigation; Injured Control (n=12): no decontamination treatment. After 7 or 14 days in MOPS, tissues were assessed by quantitative microbial culture and Viable Chondrocyte Density (VCD) measures. Results: Captive bolt trauma consistently resulted in type 3 open articular fractures. Injured Control osteoarticular fragments produced high polymicrobial counts at days 7 and 14. Chlorhexidine treatment was effective for decontaminating fragments such that no CFUs for clinically relevant bacteria were produced, while Betadine treatment was not fully effective at decontamination. Chlorhexidine decontamination followed by MOPS preservation maintained VCD in osteoarticular tissues over the desired 70% mean for 14 days, whereas the Injured Control group was associated with significant loss of VCD (Day-7=59%, Day-14=13%), which was further exacerbated by Betadine treatment (Day-7=29%, Day-14=6%). Conclusion: Contaminated, devascularized osteoarticular fracture fragments can be effectively decontaminated while maintaining essential chondrocyte viability for 14 days after type 3 open articular fractures using a decontamination-preservation protocol that combines saline irrigation with 0.002% chlorhexidine immersion followed by shelf-stable point-of-care storage in MOPS.

Use of porous adhesive cement for fixation of fragments in fractures of the lower jaw

BACKGROUND:The preferred method of treating mandibular fractures is surgical, but it also has problems due to a number of complications associated with the presence of a metal structure in the surgical wound. AIM:To improve the efficiency of surgical treatment for mandibular fractures by developing and experimentally testing amethod for fixing mandibular fragments using porous adhesive cement. MATERIAL AND METHODS:The experiments were performed on 30male Agouti guinea pigs, which were divided into two groups: the main group— 20animals, the comparison group— 10guinea pigs. A mandible fracture was modeled in all animals. In the main group, the fragments were fixed with porous glue-cement “Rekost”, in the comparison group— with abone wire suture. All animals received prophylactic antibacterial therapy. All manipulations were performed under combined anesthesia. The statistical significance of the differences in the compared groups was assessed using Fisher's criterion. For all comparisons, the selected level of statistical significance was 5% (p≤0.05). RESULTS:The use of the method developed by us for fixation of bone fragments in mandible fractures allowed us to achieve a positive result in all 20laboratory animals included in the study. This was confirmed by the results of histological studies in the dynamics of observation: a reliable difference was established between the main group and the comparison group in the severity of inflammation signs on the 14th day, as well as the severity of regeneration signs. It was found that the use of porous glue-cement for fixation of mandible fragments, in contrast to bone wire suture, allows for reliable consolidation of bone fragments for the entire period of treatment (according to X-ray diagnostic data) and to stop by the 14th day (according to histological studies) signs of inflammation in the bone wound (no leukocyte infiltration and vascular congestion). In this case, the glue allows filling the fusion area with developing bone tissue by the 90th day of observation (according to histological studies) and excluding repeated surgical intervention to remove the fixing structure, since the porous adhesive cement, according to histological studies, was absorbed by the 90th day of observation, which indicates its biodegradable properties. CONCLUSION:The use of porous adhesive cement for fixation of mandibular fragments demonstrated better properties compared to bone wire suture.

A preclinical model for osteoarticular fracture fragment preservation for delayed re-implantation

BackgroundOpen articular fractures often include contaminated, devascularized osteoarticular fragments that are critical for joint reconstruction. Definitive treatment is often delayed such that decontamination and preservation of critical fragments for joint reconstruction is highly desirable. To validate decontamination and preservation protocols for safe and effective preservation of osteoarticular fragments for re-implantation, a preclinical animal model for inducing type 3 open articular fractures with contaminated, devascularized osteoarticular fragments was developed and validated. Materials and methodsWith IACUC approval, purpose-bred hounds (n = 5) were humanely euthanized. Immediately following euthanasia, a penetrating captive bolt pistol with 1.25 grain cartridge centered on the cranial aspect of each distal humerus was discharged to create open fractures in 3 dogs (6 elbows). In 2 dogs, matched osteoarticular tissues from non-injured elbows (controls) were retrieved for comparison. Distal humerus, proximal radius, and proximal ulna osteoarticular fragments (n = 27) were immediately placed in Missouri Osteochondral Preservation System (MOPS) solution and stored at room temperature. Radiographic, chondrocyte viability, and quantitative microbial culture assessments were performed immediately (time-0) and at 7 and 14 days of storage. ResultsThis preclinical canine model reliably produced type 3 open distal humeral fractures characterized by devascularized and contaminated osteoarticular fracture fragments. All fragments produced extensive microbial growth through 14 days of storage. Without decontamination, viable chondrocyte density in the fragments decreased significantly within 7 days, likely attributable to the profound contamination. ConclusionThese data highlight the importance of developing a reliable method for point-of-care decontamination and preservation of osteoarticular fracture fragments for safe and effective reimplantation of articular fracture fragments for joint reconstruction.

The outcomes of surgical treatment of complex radial head fractures.

The aim of this study was to evaluate the outcome of complex radial head fractures at mid-term follow-up, and determine whether open reduction and internal fixation (ORIF) or radial head arthroplasty (RHA) should be recommended for surgical treatment. Patients who underwent surgery for complex radial head fractures (Mason type III, ≥ three fragments) were divided into two groups (ORIF and RHA) and propensity score matching was used to individually match patients based on patient characteristics. Ultimately, 84 patients were included in this study. After a mean follow-up of 4.1 years (2.0 to 9.5), patients were invited for clinical and radiological assessment. The Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire score were evaluated. Patients treated with ORIF showed significantly better postoperative range of motion for flexion and extension (121.1° (SD 16.4°) vs 108.1° (SD 25.8°); p = 0.018). Postoperative functional scores also showed significantly better results in the ORIF group (MEPS 90.1 (SD 13.6) vs 78 (SD 20.5); p = 0.004). There was no significant difference between the groups in terms of the complication rate (RHA 23.8% (n = 10) vs ORIF 26.2% (n = 11)). Implant-related complications occurred in six cases (14.3%) in the RHA group and in five cases (11.9%) in the ORIF group. Irrespective of the patient's age, sex, type of injury, or number of fracture fragments, ORIF of the radial head should be attempted initially, if a stable reconstruction can be achieved, as it seems to provide a superior postoperative outcome for the patient compared to primary RHA. If reconstruction is not feasible, RHA is still a viable alternative. In the surgical treatment of complex radial head fractures, reconstruction shows superior postoperative outcomes compared to RHA. Good postoperative results can be achieved even after failed reconstruction and conversion to secondary RHA. Therefore, we encourage surgeons to favour reconstruction of complex radial head fractures, regardless of injury type or number of fragments, as long as a stable fixation can be achieved.

Three- or four-part proximal humeral fractures in middle-aged and active elderly group of patients: a narrative review of treatment options.

Proximal humerus fractures (PHFs) occur in all age groups but more in elderly population with variety of treatment options. The choice of treatment of PHFs is rather controversial in the middle-aged and active elderly population. This review article highlights the current literature on the efficacy of treatment options for PHFs in middle-aged and active elderly patients which could help surgeons in decision making in clinical practice. PubMed and Scopus databases from January 1953 to February 2024 were searched and screened for studies, including systematic reviews, on the treatment of PHFs in middle-aged and elderly that served for narrative review of rationale behind such design. Patients with minimally displaced fractures should be treated nonoperatively. Internal fixation with intramedullary nailing is a viable option in cases of two-part surgical neck fractures, those with diaphyseal involvement and no significant displacement of the tuberosities, or pathologic fractures. Those elderly patients with displaced three- or four-part PHFs fractures with intact rotator cuff muscles should be treated with locking plate fixation if anatomical reduction of fracture fragments including tuberosity is possible, as the results after union despite avascular necrosis are favorable. Moreover, patients with failed fixation treated with salvage reverse shoulder arthroplasty (RSA) have similar outcomes to RSA for acute PHFs. Hemiarthroplasty should be reserved for select group of young active patients with unconstructable fracture, intact rotator cuff, and good tuberosity bone stock. RSA should be offered as first option for elderly patients with poor bone stock, rotator cuff insufficiency, fracture dislocations, head-split fractures, and severely displaced 3- and 4-part PHFs. The treatment of choice in middle-aged and active elderly patients with three- or four-part PHFs depends on several factors such as fracture pattern, bone quality, possibility of anatomical reduction, status of rotator cuff, and patient expectations. The success of treatment is based on patient selection while setting correct patient expectations.

Arthroscopic Fixation With Absorbable Suture Anchors for Pipkin Type I Femoral Head Fractures—Letter V Technique

Femoral head fractures are relatively uncommon high-energy injuries and usually associated with traumatic hip dislocation. Pipkin classified these fractures into 4 types according to the location of the head fragment related to the fovea and associated lesions on the femoral neck or acetabulum. Traditional open reduction and internal fixation for femoral head fracture has been proven to be effective, but it could be associated with significant complications. Arthroscopic fixation with screws is a less-invasive alternative to open reduction and internal fixation that offers several advantages. However, technical challenges could be encountered during the procedure and catastrophic consequences could occur in cases of fixation failure. Therefore, we propose an effective arthroscopic technique for Pipkin type I (small fracture caudal to the fovea capitis) femoral head fractures that uses an absorbable suture anchors. The anchors provide initial stability to the fracture fragments, and then the sutures are tied in a double-pulley fashion to further secure the fracture. Finally, a triangular suture bridge (“letter V”) is created, which supplies a convenient and stable fixation for proper femoral head fracture.

Comparison of three methods of greater trochanter fixation in intertrochanteric femur fractures (AO type 31/A2) treated with cementless bipolar hemiarthroplasty

Aim: The aim of this study was to compare the three most commonly used fixation methods for the fractured trochanter major fragment in patients undergoing uncemented bipolar hemiarthroplasty for unstable intertrochanteric fractures. Methods: The medical records of 231 acute hip fracture cases aged 65 years and older with AO classification 31/A2.2 and 31/A2.3 who underwent unilateral primary cementless bipolar hemiarthroplasty at Adana Şehir Training and Research Hospital between January 2021 and January 2023 were retrospectively analyzed. The files were classified into three groups based on the fixation technique used in the operation. Results: There were 231 files, with a mean age of 82.3±7.9. The majority (55.8%) were classified as ASA III. The analysis resulted in no significant differences between the groups in terms of age, number of days between the day of the injury and the day of the surgery, fixation failure, nonunion, number of revision surgeries, hospitalization duration, and HHS recorded at the third and sixth-month follow-up visits. Among the 73 males and 158 females, the ratio of the side in which the fracture occurred showed no difference (p=0.854). The female rate was significantly higher in group 3 compared to other groups (p=0.003). Regarding union success, cases in group 1 had significantly lower trochanter major union rates (p

Sagittal Fragment Rotation and Ogden Type-I Classification Are Hallmarks of Combined Tibial Tubercle Fracture and Patellar Tendon Injury.

Tibial tubercle fractures (TTFs) are uncommon injuries, comprising <3% of all proximal tibial fractures. These fractures occasionally occur in conjunction with a patellar tendon injury (PTI). We aimed to identify risk factors associated with combined TTF and PTI. A retrospective review was performed of patients presenting to a single, tertiary children's hospital with TTF between 2012 and 2023. Demographic data, operative details, radiographs, and injury patterns were analyzed. Radiographs were assessed for the epiphyseal union stage (EUS), Ogden classification, and fracture patterns. Multiple logistic regression models were used to assess the impact of body mass index, comminution, fracture fragment rotation, EUS, bilateral injury, and Ogden classification on injury type. We identified 262 fractures in 252 patients (mean age, 13.9 ± 1.31 years). Of the patients, 6% were female and 48% were Black. Of the 262 fractures, 228 (87%) were isolated TTFs and 34 (13%) were TTFs with PTI. Multivariable analysis demonstrated fragment rotation on lateral radiographs (p < 0.0001) and Ogden Type-I classification (p < 0.0001) to be the most predictive risk factors for a combined injury. Rotation was associated with a substantial increase in the odds of a combined injury, with an odds ratio of 22.1 (95% confidence interval [CI], 6.1 to 80.1). Ogden Type-I fracture was another significant risk factor, with an odds ratio of 10.2 (95% CI, 3.4 to 30.4). The Ogden classification and fragment rotation are the most useful features for distinguishing between isolated TTF and combined TTF with PTI. This is the first study to identify risk factors for TTF combined with PTI. Surgeons may use this information to aid in preoperative planning. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Evaluation of Fracture Resistance of Reattached Tooth Fragments Restored Using Fiber-reinforced Composites: A Systematic Review.

This systematic review examined the current literature to evaluate the fracture resistance of the tooth fragments reattached using fiber-reinforced composites (FRC). An electronic search was performed on Scopus, PubMed, and Web of Science databases according to specific inclusion and exclusion criteria to identify relevant articles to be included until January 2023. Articles with full text available in the English language for randomized control studies, observational studies, retrospective studies, and in vitro studies conducted on permanent human teeth were selected. The risk of bias was assessed in all studies using the OHAT tool. Out of 16 search results, seven in vitro studies with a total of 415 samples were included in the review. Three studies reported that reinforcement using rigid FRC posts improves fracture resistance of reattached anterior teeth, three studies reported that reinforcement using flexible fiber bundles enhances the fracture strength of reattached posterior teeth and one study reported that the use of flexible polyethylene fibers improves fracture resistance in molars with reattached cusps. Within the limitations of the studies included in the review, there is low-quality evidence that reinforcement of reattached fragments using FRC posts or fibers improves fracture resistance. The reattached fractured fragments may be susceptible to re-fracture. The use of FRC to reinforce the resin composite used for reattachment may enhance the bond strength and increase resistance to fracture. How to cite this article: Albar NHM. Evaluation of Fracture Resistance of Reattached Tooth Fragments Restored Using Fiber-reinforced Composites: A Systematic Review. J Contemp Dent Pract 2024;25(6):605-615.

Dynamic fracture mechanism and fragment characteristics of sandstone specimens with asymmetrical conjugate fissures under static pre-compression

This paper systematically investigates the dynamic mechanical response and fragment characteristics of sandstone with asymmetrical conjugate fissures subjected to preexisting static stress based on the split Hopkinson pressure bar apparatus. The cross-fissured sandstone exhibits significant variations in mechanical behavior when exposed to higher dynamic strain rates under identical static pre-stress. The cross-fissured sandstone with a higher dynamic strain rate is characterized by a greater coupled strength under the same static pre-stress; for a given dynamic load, the highest coupled strength occurs under the static pre-stress of 60% UCS. The failure mode of the cross-fissured sandstone is predominantly governed by the dynamic strain rate, independent of static pre-stress variations considered in this investigation. At lower dynamic strain rates, the specimens typically exhibit a mixed tensile-shear failure mode, characterized by the dominance of larger fragments in the broken specimens. In contrast, under high dynamic impacts, the sandstone tends to fail in a shear-dominated manner, resulting in smaller fragments with a more uniform size distribution. Furthermore, the study explores how varying dynamic strain rates and static pre-stress influence the fragment characteristics of the cross-fissured sandstone. Higher dynamic strain rates and increased static pre-stress generally lead to smaller mean fragment sizes. This phenomenon is quantitatively described by fitting fragment size distributions using the Generalized Extreme Value (GEV) distribution, revealing a decrease in the location parameter (μ) and an increase in fractal dimension. These metrics indicate that higher dynamic strain rates and static pre-stress result in sandstone specimens breaking into smaller fragments with a more homogeneous size distribution. These findings contribute to a deeper understanding of rock dynamics, with potential implications for engineering applications involving similar geological configuration under dynamic loading conditions.

Outcomes of Percutaneous Fixation in Intra-articular Calcaneal Fractures.

Displaced intra-articular calcaneal fractures have been proven to be challenging fororthopaedicsurgeons worldwidedue to the poor clinical outcomes. Historically, the decision whether for fixation or conservative management depended mostly on the literature of the time, initiallyfavouringconservative management but attitudes slowly shifted to operative intervention. Percutaneous fixation options have been increasingly popular for their ability for fracture reduction without skin and wound complications of the open method.A retrospective study of 17 patients with a total of 18 calcaneal fractures treated in our hospital by a single surgeon from January 2017 to December 2019 was conducted. Fixation was done percutaneously using cannulated screws, with the patients in a lateral position. Intraoperative imaging was done using a mini-image intensifier to visualise fracture reduction, and the O-arm was used in most cases.Using the Sanders classification, there were a total of 4 IIA, 3 IIB, 2 IIC, 2 IIIAB, and 7 IIIAC.Results showed that 16 calcaneal fractures (94%) had good to excellent outcomes with the American Orthopedic Foot and Ankle Society (AOFAS) score and Maryland Foot Score (MFS), while 14 calcaneal fractures (78%) showed good to excellent outcomeswith the Kerr calcaneal score. There were no wound complications encountered in our series. However, there was one patient with a k-wire broken intraoperative and left in situ and there were two patients with prominent screws.Despite this, our experience with percutaneous fixation of displaced intra-articular calcaneal fractures has been generallyfavourable, allowing for good outcomes and satisfactory reduction of the fracture fragments.

Cyclic fatigue resistance of two pediatric rotary files manufactured with different heat treatments: an in-vitro study.

Nickel-titanium (NiTi) instruments offer many advantages during endodontic instrumentation; however, the fracture risk within the canal remains a concern. Manufacturers continuously develop and introduce instruments to the market with supposedly enhanced cyclic fatigue resistance and increased flexibility, achieved through different proprietary manufacturing processes, the details of which have not been made public. In recent years, two rotary systems specially designed for deciduous teeth have been commercially available, but information about their performance is lacking. This investigation aimed to identify which manufacturing process provides better cyclic fatigue resistance: the AF-H Wire technology used in the AF baby rotary files (AF-f) or the CM-Wire technology used in the i3 Gold deciduous teeth rotary files (i3G-f). Forty rotary International Organization for Standardization (ISO) 25/04 files were tested in artificial canals with a standard geometry of 60° angle and 2.5 mm radius until fracture. The number of cycles to fracture was calculated, and the length of the fragments was measured. A scanning electron microscope (SEM) was used to examine the fracture surfaces and fragments. Energy dispersive spectroscopy (EDS) was used to determine the percentage weight of NiTi in each file. The statistical analysis (Mann-Whitney test) showed that the cyclic fatigue resistance of the AF-f was significantly higher (p < 0.0001) than that of the i3G-f. Additionally, there was a significant difference (p = 0.0419) in the length of the fractured fragments. All instruments showed one or more types of manufacturing defects and presented similar NiTi percentages by weight. The manufacturing process is critical to cyclic fatigue resistance, and there seems to be responsible for the difference in cyclic fatigue resistance between these similar instruments.

Management of complicated crown fracture in maxillary incisor using fragment reattachment - 5-year follow-up

Complicated crown-root fractures of maxillary incisors are a relatively common occurrence in cases of trauma to the facial region. Patients with such fractures are in acute pain and usually require emergency care on their first clinical visit. Pain management and restoration of function, esthetics, and phonetics should be the prime objective in handling such patients. The reattachment of fractured tooth fragments is a relatively simple procedure that provides natural esthetics and conservation of tooth structure. This case report describes such a reattachment procedure in a complicated crown-root fracture and its success at 5 years of follow-up.