Plate Fracture Research Articles

New generation of superior single plating vs. low-profile dual minifragment plating in diaphyseal clavicle fractures: a biomechanical comparative study

Recently, a new generation of superior clavicle plates was developed featuring the variable angle locking technology for enhanced screw positioning and a less prominent and optimized plate-to-bone fit design. On the other hand, mini-fragment plates in dual plating mode have demonstrated promising clinical results. The aim of the current study was to compare the biomechanical competence of single superior plating using the new generation plate versus dual plating using low-profile mini-fragment plates. Sixteen paired human cadaveric clavicles were pairwise assigned to two groups for instrumentation with either a superior 2.7 mm Variable Angle Locking Compression Plate (Group 1), or with one 2.5 mm anterior combined with one 2.0 mm superior matrix mandible plate (Group 2). An unstable clavicle shaft fracture (AO/OTA 15.2C) was simulated by means of a 5mm osteotomy gap. Specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with bidirectional torsion around the shaft axis and monitored via motion tracking. Initial construct stiffness was significantly higher in Group 2 (9.28 ± 4.40 N/mm) compared to Group 1 (3.68 ± 1.08 N/mm), p=0.003. The amplitudes of interfragmentary motions in terms of axial and shear displacement, fracture gap opening and torsion, over the course of 12,500 cycles were significantly higher in Group 1 compared to Group 2, p≤0.038. Cycles to 2mm shear displacement were significantly lower in Group 1 (22792 ± 4346) compared to Group 2 (27437 ± 1877), p=0.047. From a biomechanical perspective, low-profile 2.5/2.0 dual plates can be considered as a useful alternative for diaphyseal clavicle fracture fixation especially in less common unstable fracture configurations. 2.7 single superior variable angle locking plates and can therefore be considered as a useful alternative for diaphyseal clavicle fracture fixation especially in less common unstable fracture configurations.

Fatigue Failure of a Distal Radius Dorsal Spanning Locked Bridge Plate with Tendon Rupture: A Case Report and a Review of the Literature

A 63-year-old female with concomitant hip and distal radius fractures, was treated with a dorsal spanning bridge plate fixation of the distal radius to allow immediate upper extremity weight-bearing. At nine weeks postoperatively, the plate fractured through its central screw holes, rupturing the extensor pollicis longus (EPL) tendon and requiring implant removal and tendon transfer. Low-profile bridge plates in distal radius fractures can result in early fatigue failure and tendon injury. Stouter plates and/or low-profile plates without midplate holes, should be considered when immediate weight-bearing through the injured wrist is needed.

Experimental study on proppant-carrying migration and settlement of slickwater in narrow plate fractures based on PIV / PTV

Hydraulic fracturing is the primary method used for oilfield stimulation, and the migration and settlement pattern of proppant plays a crucial role in the formation of high conductivity propping fractures in the reservoir. This study summarizes two growth modes of sand dune: the ‘overall longitudinal growth’ mode and the ‘push growth along fracture length direction’ mode. To investigate these modes, a two-phase velocity test is conducted using PIV, and the exposure difference is utilized to separate the tracer and track the single-phase velocity. By analyzing the slickwater flow field and proppant velocity field, the micro-motion mechanism behind the two dune growth modes is quantitatively examined. The results indicate that mode 1 growth of the sand dune occurs when a pump with a large mesh number, high polymer viscosity, and large displacement is used. On the other hand, mode 2 growth is observed when a pump with a small mesh number, low polymer viscosity, and small displacement is employed. It is important to note that there is no clear boundary for the migration and sedimentation mode of proppant, as they can transition into each other under certain conditions. These modes only exist during specific stages of sand dune growth. In the case of the ‘backflow’ pattern, the settlement of proppant is primarily influenced by the vortex structure of slickwater. Conversely, in the ‘direct’ pattern, the proppant is propelled forward by the drag of the fluid and settles due to its own gravity. Once the proppant placement reaches equilibrium, the direction of proppant velocity follows a normal distribution within 0°. This approach establishes a connection between the overall placement of the sand dune and the microscopic movement of the proppant and slickwater. Optimizing construction parameters during fracturing construction can enhance the effectiveness of distal proppant placement in fractures.

Outcomes of Volar Plating Distal Radius Fractures Based on Surgical Timing.

While complexity of distal radius fractures varies, volar plating is the most prevalent surgical option in adult injuries. The time between date of injury and surgical intervention varies according to several factors, including the timing of presentation and the surgeon's availability. This study aims to understand the impact of a delay in surgical intervention on operative time, patient-reported outcomes, and reoperation rates. A retrospective review was performed on patients treated with volar plating of distal radius fractures from 2017 to 2020 at a single institution by multiple surgeons. Perioperative medical records were reviewed. Patients were divided into 2 groups using a cut-off date of surgery performed 12 days after injury. Descriptive analyses were used to compare demographics, fracture characteristics, operative information, and outcome data including postoperative Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores and reoperation rates between groups. A total of 257 patients were included. There was no difference in age, gender, smoking status, fracture type, or postoperative QuickDASH scores between groups. Patients fixed at 12 days or more after injury had a higher rate of reoperation, higher American Society of Anesthesiologists scores, and more surgeon experience. Volar distal radius fixation at 12 or more days after injury had no discernible differences with fracture type, operative time, or tourniquet time; however, a higher rate of reoperation was found in this group compared to earlier intervention. These data may provide important prognostic information that can be used to educate patients who present in a delayed fashion.

Axial compressive behavior of corroded double-steel-plate composite shear wall with binding bars

Steel structure is susceptible to corrosion, and corrosion will seriously affect its own load-bearing capacity and service life. In this paper, the axial compressive behavior of double-steel-plate composite shear wall (DSCW) with binding bars under different corrosion degrees is experimentally studied. The typical failure modes include the steel plate local buckling, binding bars fracture, concrete crushing, and steel plate weld tearing. The increase of corrosion rate has unfavorable influence on the axial compressive bearing capacity, initial stiffness, and ductility of DSCW. Finite element (FE) models are established to further investigate the axial compressive behavior of DSCW. It is concluded that the concrete and steel plate strength grade, the concrete section area, the steel plate thickness, and the binding bars diameter and spacing significantly affect the axial compressive bearing capacity of DSCW. A formula calculating the axial compressive bearing capacity of corroded DSCW with binding bars is proposed. The formula agrees well with the test results and can provide a reference for the engineering application.

Numerical investigation of ice plate fractures upon rigid ball impact

The fracture process and breaking capability of ice cover impacted by high-speed projectiles before underwater explosion is an urgent subject of scientific research in ice engineering applications. This paper presents the results of numerical simulations of the dynamic fracture behaviour induced by the impact of a small spherical projectile on an ice plate. The proposed 3D rate-dependent peridynamics model is validated by the dynamic ring Brazilian disc testing of ice specimens. Good agreements between the present model and the previous experiments are obtained in ice breaking processes and damage patterns of thin, medium and thick ice plates. Several cases are analysed and discussed in terms of various impact velocities, ice thicknesses, and boundary constraint conditions. The simulations identify detailed fracturing characteristics that are not observed in experiments, including the sequence and shape of crack propagation in a short time interval, the crater formation and the damage evolution along the thickness direction. The proposed peridynamics computational model provides new understanding of the potential of using penetrator–ice block impact tests to observe the evolution of complex brittle damage and reveal the failure mechanism.

Use of Locking Plates Fixed with Cortical Screws for Pelvic Fracture Repair in 20 Cats.

The aim of this study is to describe the use of String of Pearls (SOP) plates for the surgical management of feline pelvic fractures, including surgical technique, proposed indications, complications, and outcomes in a cohort of cats. This study is a single-center retrospective clinical case series. Medical records (2015-2019) of cats presenting for pelvic fractures (n = 33) were reviewed. Type of fracture, preoperative and postoperative imaging, and complications were retrospectively retrieved. Owners were contacted via questionnaire for medium- and long-term follow-up. A total of 20 cats met the inclusion criteria. Minor intraoperative complications were encountered in three patients. One patient suffered a major intraoperative complication. Five major complications were encountered postoperatively. These included two greater trochanter osteotomy fixation implant removal and three SOP plate removal. Full function was recovered in all patients according to the owners' assessment. The use of SOP plates in feline pelvic fractures appears to yield a consistently good outcome with a very low incidence of canal narrowing and screw loosening. SOP plates are easy to contour and to apply along the entire pelvic length.

Biomechanical study of the fixation ability of the dorsal and volar locking plate for transverse metacarpal neck fractures.

Metacarpal neck fracture is one of the most common types of hand fractures; the literature suggests that applying a bone plate on the dorsal side provides higher fixation strength than that provided by other fixation methods. However, bone plate fixation on the dorsal side may result in postoperative tendon adhesion. So far, no studies have investigated the fixation of metacarpal neck fractures on the volar side by using a bone plate. The objective of this study was to investigate the differences in the fixation results between bone plate fixation on the dorsal side and bone plate fixation on the volar side of the metacarpal in the case of a metacarpal neck fracture. A saw blade was used to create a transverse metacarpal neck fracture on 14 artificial metacarpal bone specimens. The specimens were divided into 2 groups depending on the fixation method: a volar locking plate (VLP) group and a dorsal locking plate (DLP) group. All specimens were subjected to a cantilever bending test on a material testing system, and a force-displacement curve was used to measure the yield force and stiffness, which served as an indicator of the fixation ability of the 2 fracture fixation methods. For the experimental results, the Mann-Whitney U test was used to compare the fixation abilities of the 2 fixation methods. In terms of yield force, the DLP group (266.9 ± 68.3 N) scored significantly higher than the VLP group (32.6 ± 2.7 N) (P < .05); expressed in terms of median, the DLP group scored 8.2 times higher than the VLP group. Similarly, in terms of stiffness, the DLP group (69.0 ± 13.4 N/mm, median ± interquartile range) scored significantly higher than the VLP group (12.9 ± 1.4 N/mm) (P < .05); expressed in terms of median, the DLP group scored 5.3 times higher than the VLP group. The fixation strength of volar bone plates is only about one-third of that of dorsal bone plates.

Conventional avulsion versus less traumatic extraction of ankylosed roots with a magnetoelectric device in anterior maxillary areas

The analysis aimed to compare two different single-tooth extraction surgical approaches in anterior maxillary areas of the ankylosed teeth: less traumatic magneto-electrical (mag) versus conventional tooth extraction (con) in minimizing the adverse effects on post-extractive sockets. Parameters of clinical interest such as intra-surgical fracture of the buccal bone plate, presence of postoperative inflammation, and application of stitches were acquired from medical records. The data were subjected to Pearson’s χ2 analysis or to Fisher's exact test with significance at 0.05. Sixty-six hopeless maxillary permanent ankylotic teeth were extracted in the same number of patients. In the mag group 2 incisors suffered a fracture. Two patients out of 40 had signs and symptoms of inflammation that resolved completely within 3 days. In the con group 18 out of 26 patients suffered from buccal alveolar fracture. Six of these patients experienced signs of inflamed tissue. The two groups showed significant differences with p-values ≤0.0009 with regards to fracture (2/38 vs. 18/8) and tissue inflammation variables (2/38 vs. 10/16). A significantly different distribution about the presence of sutures was registered between the mag (4/36) and the con (18/8) group with a p-value <0.0001. Mag group seemed to have reduced frequency of fractured and infected post-extractive sites.

Comparison of physics forceps to conventional forceps in simple dental extraction

Background: In this study, Conventional forceps &amp; Physics forceps were compared in simple dental extractions with respect to crown and root fracture of tooth during extraction, alveolar bone plate fracture, gingival laceration, requirement of sutures, duration of surgery, comparative pain evaluation through visual analogue scale and analgesic requirement in the first 24 hours post operatively. Methods: This study was conducted at our centre where 200 patients requiring simple dental extractions were randomly divided into two groups, each having 100 patients. Extractions in one group were done using Conventional forceps and in other group were done using Physics forceps. All parameters were measured during surgery &amp; questionnaires were given to all the patients to assess the pain perception &amp; analgesic requirement postoperatively till 24 hours. Results: The results of present study showed decreased incidence of crown and root fracture of tooth, alveolar bone plate fracture, gingival lacerations, requirement of sutures, lesser duration for extraction and lesser pain perception in Physics forceps group. No significant difference was found between two groups for analgesic intake. Conclusions: Physics forceps group patients had superior results compared to patients in Conventional forceps group which may be attributed to lesser hard and soft tissue injuries and better pain control in Physics forceps group.

Comparison of a 2.7-mm and 3.5-mm locking compression plate for ulnar fractures: a biomechanical evaluation.

Implant prominence after ulnar fracture fixation may be mitigated by the use of lower profile plates. The biomechanical strength and stability of 2.7-mm and 3.5-mm locking compression plates for fixation were compared. Two fracture conditions, transverse (N = 10) and oblique (N = 10), were evaluated in an in vitro study. Half of the specimens for each condition were fixed with 2.7-mm plates and the other half with 3.5-mm plates, all fixed with conventional dynamic compression mechanisms. Specimens were loaded under ±2 Nm of cyclic axial torsion, then under 10 Nm of cyclic cantilever bending, and bending to failure. Interfragmentary motion and strain were analyzed to determine construct stability as a function of fracture pattern and plate size. Interfragmentary motion was significantly larger in all constructs fixed with 2.7-mm plates, compared with 3.5-mm plates (P < 0.01). The 2.7-mm constructs with transverse fractures had the greatest motion, ranging between 5° and 10° under axial rotation and 5.0-6.0 mm under bending. Motions were the lowest for 3.5-mm constructs with oblique fractures, ranging between 3.2 and 4.2 mm under bending and 2°-3.5° for axial rotation. For oblique fractures, the bending moment at ultimate failure was 31.4 ± 3.6 Nm for the 2.7-mm constructs and 10.0 ± 1.9 Nm for 3.5-mm constructs (P < 0.01). Similarly, for transverse fractures, the bending moment was 17.9 ± 4.0 Nm for the 2.7-mm constructs and 9.7 ± 1.3 Nm for the 3.5-mm constructs (P < 0.01). Although 3.5-mm plates were more effective at reducing fracture motion, they were consistently associated with refracture at the distal-most screw hole under load to failure. By contrast, 2.7-mm plates plastically deformed despite excessive loads, potentially avoiding a subsequent fracture. Level V.

Comparative Outcomes of Anterior and Posterior Plating for Distal-Third Humerus Shaft Fractures

When treating distal-third humerus shaft fractures (HSFs) surgically, the optimal approach for plating is controversial. We conducted a retrospective multicenter study to investigate and compare the clinical outcomes of anterior and posterior plating in distal-third HSFs and the incidence of complications including iatrogenic radial nerve palsy. We identified 116 patients from our multicenter trauma database who were diagnosed as having distal-third HSFs and who underwent surgical treatment, including intramedullary nailing between 2011 and 2020. We analyzed 50 cases treated in one of two ways: open reduction internal fixation with anterior plating (group A: 20 cases) and open reduction internal fixation with posterior plating (group P: 30 cases). The findings were similar in terms of operation time, estimated bleeding, and clinical and radiographic outcomes between the groups. Postoperative radial nerve palsy occurred only in group P (4 cases) and never in group A. The results of this study suggest that the anterior approach is a safe and effective method for treating distal-third HSFs with satisfactory outcomes. Therapeutic IV.

Biomechanical Analysis of Combined Medial Calcar and Lateral Locked Plating Versus Isolated Lateral Locked Plating of Proximal Humerus Fractures.

Medial calcar buttress plating combined with lateral locked plating is biomechanically tested against isolated lateral locked plating in synthetic humeri models for the treatment of proximal humerus fractures. Proximal humerus fractures (OTA/AO type 11-A2.1) were manufactured in 10 pairs of Sawbones humeri models (Sawbones, Pacific Research Laboratories, Vashon Island, WA). Specimen were randomly assigned and instrumented with either medial calcar buttress plating combined with lateral locked plating (CP) or isolated lateral locked plating (LP). Nondestructive torsional and axial load tests were performed to evaluate construct stiffness. Large-cycle axial tests were conducted followed by destructive ramp-to-failure tests. Cyclic stiffness was compared in both nondestructive and ultimate failure loads. Failure displacement was recorded and compared between groups. The addition of medial calcar buttress plating to lateral locked plating constructs significantly increased the axial ( P < 0.01) and torsional ( P < 0.01) stiffness of the construct compared with isolated lateral locked plating by 95.56% and 37.46%, respectively. All models demonstrated greater axial stiffness ( P < 0.01) after 5000 cycles of axial compression, not dependent on the fixation method. During destructive testing, the CP construct withstood 45.35% larger load ( P < 0.01) and congruently exhibited 58% less humeral head displacement ( P = 0.02) before failure when compared with the LP construct. This study demonstrates the biomechanical superiority of medial calcar buttress plating when combined with lateral locked plating as compared with isolated lateral locked plating of OTA/AO type 11-A2.1 proximal humerus in synthetic humeri models.

Assessment of Intraoperative Complications Associated with Extraction Technique Using Physics Forceps and the Conventional Method: A Split-mouth Comparative Study

Tooth extraction is one of the most frequently performed surgeries, and several instruments were invented throughout history. This study's purpose is to assess the efficacy of physics forceps in comparison to conventional tooth extraction forceps in bilateral dental extraction and their associated intraoperative complications, including crown fracture, root fracture, buccal cortical plate fracture (BCPF), gingival lacerations, and bleeding time. All participants (n = 20) and total extractions (n = 40) were randomly assigned within two groups. Teeth were extracted utilizing physics forceps on one side of the maxillary or mandibular quadrants (n = 20) and conventional forceps on the other side (n = 20). Clinical data were gathered and analyzed. The findings show none of the patients in any of the groups had a crown fracture, however, the occurrence of roots and buccal cortical plate fractures were higher within control group. The incidence of gingival lacerations was seven times (35 %) in the study group and eight times (40 %) in the control group. Bleeding time in control group was longer than that in the study group (P value = 0.022) with a moderate effect size (ES = 0.676). In this study, buccal traumatic ulcer formation was observed in 5 cases (25 %) in study group due to excessive pressure application on the buccal soft tissue. In conclusion, physics forceps provide clinical outcomes comparable to conventional forceps and could be used for routine exodontia.

Comparison of Noncontact Plating with Conventional Methods and Osteosynthesis Techniques in the Treatment of Pediatric Femoral Fractures

Introduction: Studies on surgical options in pediatric femoral fractures have been continuing for many years. We aimed to compare the noncontact plating we applied with the other techniques.&#x0D; Material and Methods: Pediatric patients treated for femoral shaft fracture were included. The patients were evaluated in terms of fracture type, time until surgery, duration of surgery, time of union, complications, Flynn criteria, radiological findings. 21 were in the elastic nailing (group 1), 27 were in the conventional plating (group 2), 11 were in the noncontact plating (group 3). &#x0D; Results: The mean age was 8.3±1.4 (6-11) in group 1, 10.2±2.2 (7-15) in group 2, and 9.7±2.8 (7-15) in group 3. The time of union was 8.0±2.2 weeks (6-16) in group 1, 9.7±2.7 weeks (7-20) in group 2, and 7.1±1.0 weeks in group 3 (6 -9). In group 1, one patient had delayed union, two patients had a valgus deformity, two patients had minor wound site infection, and four patients had shortening of less than 2 cm. In group 2, three patients had a valgus deformity.Moreover, one patient underwent revision due to plate fracture. In group 3, no delayed union or deformity was observed in any patient.&#x0D; Conclusion: The fact that elastic nailing, which is the most frequently recommended method in pediatric femoral fractures. However, it is obvious that conditions such as the absence of splinting, better reduction, fewer deformity, early rehabilitation provide advantages over noncontact plating. While it is up to the surgeon's preference, noncontact plating can be applied safely and successfully.

Alloplastic reconstruction of the mandible after subtotal mandibulectomy for medication-related osteonecrosis of the jaw: An update of the method.

Reconstruction of continuity defects following osteonecrosis in multimorbid patients is challenging. In all cases of the predescribed palliative treatment method for alloplastic mandible reconstruction, plate fractures were detected in follow-up. We hypothesized that a modification could avoid these fractures, leading to stable long-term results. This retrospective study compares the original method with a modification using single, laser-sintered CAD-CAM plates instead of manually bent miniplates. The predescribed shuttering technique was used to reconstruct the mandible in its original shape with bone cement. Uneventful wound healing was observed in 86% of the cases after modification of the method. No implant or plate fracture occurred. The presented method should be considered as a treatment option for mandible reconstruction in elderly, multimorbid patients in palliative situations. The results of this study suggest that the modification of the method leads to significantly improved long-term stability. Donor site morbidity is avoided with this method of palliative surgery.

Preparation Method and Properties of Q235/5083 Composite Plate with 1060 Interlayer by Differential Temperature Rolling with Induction Heating

Due to their exceptional all-around performance, steel/aluminum-alloy composite plates have been frequently utilized in many different industries. However, when steel/aluminum-alloy composite plates are prepared by the rolling process, they will scarcely bond with high bonding strength under a lower reduction rate due to the inconsistent deformation the of steel/aluminum-alloy. Therefore, a method of adding a pure-aluminum interlayer by differential temperature rolling with induction heating was proposed to prepare steel/aluminum-alloy composite plates. The results showed that when the induction heating time was 10–18 s, the pure-aluminum interlayer became molten, and the temperature difference between the steel and aluminum alloy reached 350–500 °C. The interface shear strength of the composite plate reached more than 68 MPa under a 31% reduction rate. The shear fracture of the composite plate occurred in the pure-aluminum layer, and the steel/aluminum interface diffusion layer was 0.83–0.99 μm thick. There was no obvious compound formation at the bonding interface, however, the steel and aluminum alloy could not bond without the addition of an interlayer under the same conditions.

The study of biomechanics and finite element analysis on a novel plate for tibial plateau fractures via anterolateral supra-fibular-head approach

For Schatzker type II split-depressed tibial plateau fractures involving the fractures of anterolateral and posterolateral columns (APC), the optimal fixation scheme is controversial. The objectives of this study were: (1) to introduce a newly designed plate for treating APC fractures via biomechanical tests and finite element analysis (FEA), and (2) to compare it with two conventional fixation methods. APC fracture models were created and randomly assigned to three groups (Groups A-C). Group A was fixed with a 3.5-mm lateral locking plate, Group B was fixed with a 3.5-mm lateral locking plate and two 3.5-mm cannulated screws (hybrid fixation). Group C was fixed with the newly designed plate. It is an arched locking plate for fixing the lateral tibial plateau via the anterolateral supra-fibular-head approach. Each fracture model experienced a gradually increasing axial compressive load ranging from 250 to 750 N using a customized indenter. Biomechanical analysis demonstrated that the newly designed plate showed the minimum displacement among the three methods, followed by the hybrid fixation method. Conversely, the 3.5-mm lateral locking plate displayed the maximum displacement in APC fractures (p < 0.05). FEA results indicated that at 750 N, the maximum displacements for Groups A-C were measured as 3.06 mm, 2.74 mm, and 2.08 mm, respectively. Moreover, the maximum stresses recorded for the implant in Groups A-C at 750 N were 208.32 MPa, 299.59 MPa, and 143.26 MPa, while for the bone, they were 47.12 MPa, 74.36 MPa, and 40.01 MPa. The overall trends at 250 N and 500 N were consistent with those observed at 750 N. In conclusion, due to good biomechanical performance and FEA results, the newly designed plate represents a promising choice for managing APC fractures of the tibial plateau.

Prediction of fracture nonunion leading to secondary surgery in patients with distal femur fractures.

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures. We conducted a retrospective cohort study of adult patients with traumatic distal femur fracture treated with lateral locking plate between 2009 and 2018. The patients who underwent secondary surgery due to fracture healing problem or plate failure were considered having nonunion. Background knowledge of risk factors of distal femur fracture nonunion based on previous literature was used to form an initial set of variables. A logistic regression model was used with previously identified patient- and injury-related variables (age, sex, BMI, diabetes, smoking, periprosthetic fracture, open fracture, trauma energy, fracture zone length, fracture comminution, medial side comminution) in the first analysis and with treatment-related variables (different surgeon-controlled factors, e.g. plate length, screw placement, and proximal fixation) in the second analysis to predict the nonunion leading to secondary surgery in distal femur fractures. We were able to include 299 fractures in 291 patients. Altogether, 31/299 fractures (10%) developed nonunion. In the first analysis, pseudo-R2 was 0.27 and area under the receiver operating characteristic curve (AUC) was 0.81. BMI was the most important variable in the prediction. In the second analysis, pseudo-R2 was 0.06 and AUC was 0.67. Plate length was the most important variable in the prediction. The model including patient- and injury-related factors had moderate fit and predictive ability in the prediction of distal femur fracture nonunion leading to secondary surgery. BMI was the most important variable in prediction of nonunion. Surgeon-controlled factors had a minor role in prediction of nonunion.

Competitive fretting fatigue failure analysis of Al alloy–CFRP riveted and adhesive–riveted single-shear lap joints

Fatigue tests on Al alloy–carbon fibre reinforced plastic (CFRP) single-shear lap riveted joints and adhesive–riveted hybrid joints are conducted to reveal the failure mechanisms of joints under different loads. The novelty of this study is that the effect of heat accumulation caused by interfacial friction on joint competitive failure is considered. Results show that the Al–CFRP joint is a typical competitive fretting fatigue, and the failure modes of heterogeneous joints are affected by the sensitivity of the mechanical properties of materials due to the external environment change. The failure location of the joint under low load is the Al plate. As the load increases, the joint enters a gross slip state accompanied by a temperature rise. In addition, the performance of the CFRP decreases significantly, leading to the fracture of the CFRP plate. The existence of the adhesive slows down the interfacial wear, which can improve the service life by 500% under lower loads, but it cannot prevent the temperature rise under higher loads and only improves the life by 80%. When selecting life-enhancing methods in engineering applications, the hybrid joint can be considered under low loads, and high-temperature-resistant composites are recommended under high loads.