Independent volumetric internal fixation reduces posterior column acetabular fracture site motion as compared to plate/screw construct: A biomechanical analysis.

Aims & objectives: To establish whether a suprapectineal pelvic reconstruction plate and posterior column screw (P&S) construct or a single 6.5-mm cannulated posterior column screw (PCS) construct demonstrates greater mechanical stability for fixation of acetabulum fractures involving the posterior column (PC). We hypothesized that the PCS construct would result in less fracture site motion. Materials & methods: Twelve fourth-generation composite hemipelvi were utilized, 6 for each construct. The P&S construct consisted of a suprapectineal pelvic reconstruction plate with two 3.5-mm posterior column screws crossing the fracture site in lag-by-technique fashion and two screws anchoring the plate to the sciatic buttress. The PCS construct consisted of a single 6.5-mm partially threaded cannulated screw placed in an antegrade fashion. Both fixation models were cyclically loaded at 0.5 cycles/second at 400N and 800N, first in a sit-to-stand position that is expected during recovery, and subsequently in a squat-to-stand position to test overload conditions. Results: Under sit-to-stand loading, the PCS construct resulted in less motion at the fracture site than the P&S construct (0.06 ± 0.02 mm vs 0.1 ± 0.02 mm at 400N, p = 0.02; 0.13 ± 0.03 mm vs 0.19 ± 0.04 mm at 800N, p = 0.03). The PCS construct also demonstrated less fracture site motion under squat-to-stand loading (0.22 ± 0.13 mm vs 1.9 ± 0.5 mm at 400N, p = < 0.001; 1.48 ± 0.44 mm vs 4.77 ± 0.3 mm at 800N, p = < 0.001). At 800 N, half of the repairs failed during squat-to-stand loading (2 PCS, 4 P&S). Conclusion: Fixation of the posterior column of the acetabulum with a 6.5-mm cannulated screw demonstrated comparable fracture motion upon loading compared to the plate and screw construct.

Mitigating calcar fracture risk with automated impaction during total hip arthroplasty.

Background: Automated broaching has recently been introduced for total hip arthroplasty (THA), with the goal of improving surgical efficiency and reducing surgeon workload. While studies have suggested that this technique may improve femoral sizing and alignment, little has been published regarding its safety, particularly with regard to calcar fractures. The purpose of our study was to evaluate the risk of calcar fracture during automated broaching, and to determine if this risk can be mitigated. Methods: We queried our prospective institutional database and identified 1596 unilateral THAs performed by the senior author using automated impaction between 2019 and 2023. We identified the incidence of calcar fracture with automated impaction, and whether the fracture occurred during broaching or stem insertion. We additionally determined calcar fracture incidence within two consecutive subgroups of patients using different stem insertion techniques; subgroup (1): automated broaching with automated stem insertion for all patients; versus subgroup (2): automated broaching with automated stem insertion ONLY if a cushion of cancellous bone separated the broach from the calcar, otherwise the stem was placed manually. Continuous and categorical variables were analyzed with Student's t-test and Fisher's exact test, respectively. Results: Seventeen calcar fractures occurred intraoperatively (1.1 %). Only two fractures occurred during automated broaching (0.1 %), while fifteen occurred during final stem impaction (0.9 %) (p = 0.007). Four calcar fractures (1.4 %) occurred in subgroup 1, compared to two in subgroup 2 (0.6 %) (p = 0.28). Conclusions: Our study found a calcar fracture incidence of 1.1 % using automated impaction, consistent with historically reported rates of 0.4-3.7 %. We found that calcar fractures are more likely to occur during stem insertion than during femoral broaching. We recommend that if any part of the final broach is in direct contact with the calcar, the final stem should be impacted manually to minimize fracture risk.

A Biomechanical Analysis of Oblique Metacarpal Metadiaphyseal Fracture Fixation in a Cadaver Model.

PURPOSE: Although metacarpal fractures are typically managed nonoperatively, when surgical management is indicated, metacarpal fractures are commonly treated with crossed Kirschner wires (K-wires), which may limit early range of motion. Intramedullary implants are increasing in use with the potential advantage of early range of motion; however, stability in oblique metacarpal neck fractures remains a theoretical concern. The purpose of this study was to determine the biomechanical stability of noncompressive intramedullary fixation for oblique metacarpal neck fractures compared with crossed K-wire fixation. METHODS: The index, long, and small metacarpals were harvested from three matched pairs of fresh-frozen cadavers. Oblique fractures at the metadiaphyseal region were created in each metacarpal. Each metacarpal was randomized to noncompressive, threaded intramedullary nail fixation or fixation with two crossed K-wires. Specimens were mounted in a Materials Testing System load frame and axially loaded until failure. Load to failure (LTF), stiffness, and load to 2 mm displacement were calculated from load-displacement curves. Differences in peak LTF, stiffness, and load to 2 mm displacement between noncompressive intramedullary fixation and crossed K-wire fixation were evaluated. RESULTS: The noncompressive intramedullary fixation cohort had a significantly higher LTF (1,190.9 ± 534.7 N vs 297.0 ± 156.0 N) and stiffness (551.3 ± 164.6 N/mm vs 283.0 ± 194.5 N/mm) when compared with the crossed K-wire fixation cohort. Load at 2 mm displacement was greater in the noncompressive intramedullary fixation cohort compared with crossed K-wire fixation (820.5 ± 203.9 vs 514.1 ± 259.6). CONCLUSIONS: For oblique metadiaphyseal metacarpal fractures, noncompressive intramedullary fixation provides a biomechanically superior construct under axial loading in terms of LTF, stiffness, and load to 2 mm of displacement compared with crossed K-wire fixation. CLINICAL RELEVANCE: Noncompressive intramedullary nails may be an alternative to K-wire fixation for the treatment of oblique metadiaphyseal metacarpal fractures.

Individuals with a fragility fracture and a prescription for bone active medication have a positive perception of the medication but do not associate it with fracture risk reduction.

Most participants reported a positive perception of bone active medication despite sustaining a fracture while taking the medication, reporting medication side effects, or having a healthcare provider stop the prescription. Participants did not appear to connect the medication to fracture risk, suggesting this connection should be emphasized by healthcare providers. OBJECTIVE: Our purpose was to examine perceptions about bone active medication from individuals with a fragility fracture and a prescription for bone active medication. METHODS: In this qualitative description study, eligible participants were those who attended an Osteoporosis Canada education session, and reported sustaining a previous fragility fracture and receiving a prescription for bone active medication. We conducted one-on-one interviews and analyzed the data using the analytic hierarchy approach. RESULTS: We interviewed 32 female participants (age range 58-89 years). Based on our analysis, two themes were developed: (1) most participants spoke positively about bone active medication, indicating they were willing to start, or continue to take, their medication. Positive perceptions were held by participants who sustained a fracture while taking bone active medication, participants whose healthcare provider had stopped the prescription, and participants who reported side effects from the medication; (2) most participants did not discuss bone active medication in relation to their fracture and did not appear to connect the medication to the concept of fracture risk. Instead, participants talked about the medication in relation to bone health in general, or to bone density. CONCLUSION: Participants appeared to have positive perceptions of bone active medication, despite sustaining a fracture while taking the medication, reporting medication side effects, or having a healthcare provider stop the prescription. Participants did not connect bone active medication to the concept of fracture risk, illustrating the need for healthcare providers to emphasize the connection between fracture risk and bone active medication.

Vitamin D and hip protectors in osteosarcopenia: a combined hip fracture preventing approach.

Osteosarcopenia is an emerging clinical condition highly prevalent in the older people. Affected subjects due to their intrinsic skeletal fragility and propensity to falls are at elevated risk of hip fractures which can increase morbidity and mortality. Strategies for attenuating the impact of predisposing factors on hip fractures are not yet well defined and should derive from multidisciplinary care and collaborations. Our aim was to narratively review available data on the preventive role of vitamin D and hip protectors on hip fractures in older patients with sarcopenia. Older subjects are at high risk of vitamin D deficiency and of falls due to several concomitant factors besides osteosarcopenia. Vitamin D protective actions against hip fractures may be mediated by both skeletal (increased mineralization) and extra-skeletal (reduced risk of falls) actions. Hip protectors may act downstream attenuating the effects of falls although their use is still not yet enough widespread due to the suboptimal compliance obtained by traditional hard devices. Concomitant use of vitamin D and hip protectors may represent an effective strategy in the prevention of hip fractures which need to be tested in ad hoc designed clinical trials.

How accurately do finite element models predict the fall impact response of ex vivo specimens augmented by prophylactic intramedullary nailing?

Hip fracture prevention approaches like prophylactic augmentation devices have been proposed to strengthen the femur and prevent hip fracture in a fall scenario. The aim of this study was to validate the finite element model (FEM) of specimens augmented by prophylactic intramedullary nailing in a simulated sideways fall impact against ex vivo experimental data. A dynamic inertia-driven sideways fall simulator was used to test six cadaveric specimens (3 females, 3 males, age 63-83 years) prophylactically implanted with an intramedullary nailing system used to augment the femur. Impact force measurements, pelvic deformation, effective pelvic stiffness, and fracture outcomes were compared between the ex vivo experiments and the FEMs. The FEMs over-predicted the effective pelvic stiffness for most specimens and showed variability in terms of under- and over-predicting peak impact force and pelvis compression depending on the specimen. A significant correlation was found for time to peak impact force when comparing ex vivo and FEM data. No femoral fractures were found in the ex vivo experiments, but two specimens sustained pelvic fractures. These two pelvis fractures were correctly identified by the FEMs, but the FEMs made three additional false-positive fracture identifications. These validation results highlight current limitations of these sideways fall impact models specific to the inclusion of an orthopaedic implant. These FEMs present a conservative strategy for fracture prediction in future applications. Further evaluation of the modelling approaches used for the bone-implant interface is recommended for modelling augmented specimens, alongside the importance of maintaining well-controlled experimental conditions.

Stimulation of fracture mineralization by salt-inducible kinase inhibitors.

Introduction: Over 6.8 million fractures occur annually in the US, with 10% experiencing delayed- or non-union. Anabolic therapeutics like PTH analogs stimulate fracture repair, and small molecule salt inducible kinase (SIK) inhibitors mimic PTH action. This study tests whether the SIK inhibitor YKL-05-099 accelerates fracture callus osteogenesis. Methods: 126 female mice underwent femoral shaft pinning and midshaft fracture, receiving daily injections of PBS, YKL-05-099, or PTH. Callus tissues were analyzed via RT-qPCR, histology, single-cell RNA-seq, and µCT imaging. Biomechanical testing evaluated tissue rigidity. A hydrogel-based delivery system for PTH and siRNAs targeting SIK2/SIK3 was developed and tested. Results: YKL-05-099 and PTH-treated mice showed higher mineralized callus volume fraction and improved structural rigidity. RNA-seq indicated YKL-05-099 increased osteoblast subsets and reduced chondrocyte precursors. Hydrogel-released siRNAs maintained target knockdown, accelerating callus mineralization. Discussion: YKL-05-099 enhances fracture repair, supporting selective SIK inhibitors' development for clinical use. Hydrogel-based siRNA delivery offers targeted localized treatment at fracture sites.

A Modified Surgical Approach to the Distal Humerus: The Triceps Bundle Technique.

This paper describes a modification of the traditional fascial tongue surgical approach to the distal humerus. In particular, we describe the reflection and utilisation of radial and ulnar triceps bundles to allow complete visualisation of the distal humerus. This extensile technique allows access to the entirety of the distal humerus and provides excellent visualisation to the operating surgeon. Indications for the surgical approach include open reduction with internal fixation of fractures (both intra- and extra-articular) and total elbow replacement. Whilst standard approaches to the distal humerus are well described, this modification describes a new surgical approach that improves access and visualisation of the traditional fascial tongue technique. Alternative approaches to improve visualisation include an olecranon osteotomy; the triceps bundle modification allows excellent exposure to the distal humerus whilst avoiding complications associated with an olecranon osteotomy. The surgical technique is illustrated with intra-operative photographs, which aim to aid in guiding the surgeon in undertaking critical steps of this approach. How to cite this article: Rankin IA, Dixon J, Goffin J, et al. A Modified Surgical Approach to the Distal Humerus: The Triceps Bundle Technique. Strategies Trauma Limb Reconstr 2024;19(2):99-103.

Collapse and Occlusion of Balloon-Expandable Covered Stent in the Right Common Iliac Arteries Due to External Stress.

The patient previously underwent surgery for cervical cancer. She reported intermittent claudication, and computed tomography (CT) revealed total occlusion of the left iliac artery. We conducted endovascular treatment (EVT) using balloon-expandable covered stents (BECS). The patient underwent colostomy closure after EVT. The patient reported intermittent claudication beginning the day after the procedure. The CT showed a collapse of the distal side of the stent implanted in the right common iliac artery, accompanied by localized thrombo-occlusion. During open surgery, metal hooks typically affect the iliac artery; force transmission through the tissue may indirectly compress the iliac artery, leading to BECS failure.

Metaizeau technique in stabilizing Monteggia equivalent 1b associated proximal radial physeal injury in a rural setting: a case report.

Introduction: The Monteggia equivalent type 1b fracture, consisting of an ulnar shaft fracture and radial head dislocation, is a rare condition first described by Giovanni Battista Monteggia. The Metaizeau technique, emphasizing percutaneous intramedullary fixation to preserve bone healing and prevent growth plate damage, has gained prominence in managing these fractures. Case report: A 10-year-old boy presented with left forearm pain, swelling, and deformity following a fall while playing football. X-rays revealed a proximal fourth ulnar fracture with dorsal and lateral angulation, along with a proximal radial metaphyseal fracture showing anterior rotation and physeal extension. This fracture pattern resembled a Monteggia fracture type III but differed in the lateral proximal radial disruption via a Salter-Harris type II fracture rather than radial epiphysis dislocation. Satisfactory reduction achieved for ulna was managed with standard nailing system but could not be achieved for radial physeal injury, which was managed with Metaizeau technique. Discussion: Type 1b Monteggia equivalents involving a Salter-Harris type 2 fracture of the proximal radius with an associated proximal ulnar fracture, adherence to Monteggia fracture reduction principles is vital. Closed reduction and internal fixation are preferred treatments, with the Metaizeau technique offering advantages such as minimal invasiveness and avoidance of implant-related complications. The Metaizeau technique is particularly beneficial for displaced radial neck fractures in children, providing stable fixation while preserving the fracture environment necessary for optimal healing. Conclusion: In cases of Monteggia fracture equivalents, most proximal radial fractures typically reduce to an acceptable level following ulnar reduction. However, proximal radial physeal fractures may require specific attention to achieve satisfactory reduction. The Metaizeau technique, commonly employed in the management of isolated radial neck fractures, can be utilized to achieve this reduction to an acceptable level.

Surgical Treatment of Proximal Humerus Unicameral Bone Cyst: A Case Report.

Unicameral bone cysts (UBCs) are noncancerous, fluid-containing sacs commonly seen in the metaphysis of long bones among young individuals, mainly affecting the proximal humerus and femur. Since they are painless, 80% of patients do not experience any symptoms from UBCs unless it is complicated by a pathological or stress fracture. These patients usually present with no history of trauma, with mild pain, local tenderness, and occasionally swelling. The diagnosis of UBCS can either be an incidental finding or can be made with the help of clinical features, radiographs, and differential diagnoses of UBCs like aneurysmal bone cyst, fibrous dysplasia, enchondroma, eosinophilic granuloma, and intraosseous ganglia can be ruled out. While identifying these cysts is often straightforward, there is ongoing debate regarding the optimal management approach. We report a case of a 16-year-old female with proximal humerus UBC who presented with a pathological fracture of the right proximal humerus. The patient was initially managed conservatively. However, she sustained a refracture at the same site twice over four years. Due to fracture recurrence and residual deformity, it was treated surgically with curettage, bone grafting, and internal fixation. The normal alignment and function of the right upper limb were restored postoperatively.

Author Response: Nocturnal Infusion of Low-dose Dexmedetomidine and Propofol for Delirium Prevention.

How to cite this article: Ekkapat G, Chokengarmwong N. Author Response: Nocturnal Infusion of Low-dose Dexmedetomidine and Propofol for Delirium Prevention. Indian J Crit Care Med 2024;28(9):896.

Nocturnal Infusion of Low-dose Dexmedetomidine and Propofol for Prevention of Delirium Occurring in the ICU after Hip Fracture Surgery in Elderly Patients.

How to cite this article: Cong N, Wang D, Xue F. Nocturnal Infusion of Low-dose Dexmedetomidine and Propofol for Prevention of Delirium Occurring in the ICU after Hip Fracture Surgery in Elderly Patients. Indian J Crit Care Med 2024;28(9):894-895.

Surgical Treatment of Non-Displaced Subcapital Hip Fracture: Femoral Neck System vs. Cannulated Screws. Comparative Study. / Tratamiento quirúrgico de fractura subcapital de cadera no desplazada: Femoral Neck System vs Tornillos canulados. Estudio Comparativo.

OBJECTIVE: The objective of this study is to compare the outcomes of using the Femoral Neck System (FNS) (DePuy Synthes®) versus the use of cannulated screws (CS) in the surgical treatment of non-displaced subcapital hip fractures. MATERIALS AND METHODS: A retrospective cohort study was conducted on non-displaced subcapital hip fractures treated with CS or FNS between 2020 and 2023, with a minimum follow-up of one year. A total of 28 patients were included, 14 treated with CS and 14 with FNS. Demographic, radiological, clinical, and functional variables were analyzed. RESULTS: In the CS group, 64% were male, with a mean age of 66.5 years (SD 14.9) and an average follow-up of 22 months (range, 12-36 months). In the FNS group, 57% were male, with a median age of 60.8 years (SD 13.78) and an average follow-up of 16 months (range, 12-24 months). Regarding functional outcomes, no significant differences were found between FNS and CS in the Harris scale: 94.21 ± 11.55 for FNS and 96.50 ± 6.9 for CS (p=0.618). The total postoperative complications (FNS/CS) were 7.1% versus 43%, and implant failure with conversion to total hip replacement was 0% versus 43%, both significantly higher in the CS group (p=0.047; p=0.016, respectively). The FNS also presented a lower rate of avascular necrosis (0% versus 11.1%, p=0.391) and nonunion (0% versus 20%, p=0.163), although these differences did not reach statistical significance. CONCLUSIONS: Although both treatment methods, cannulated screws and the Femoral Neck System (FNS), showed similar short-term functional outcomes in the management of undisplaced subcapital femoral fractures, the FNS demonstrated a significantly lower rate of complications and reoperations. These results suggest that the FNS could be considered a safer and more effective option compared to cannulated screws.

Influence of Screw Length and Cement Position within the Injured Vertebra on Fixation Strength in Short-Segment Fixation of Osteoporotic Thoracolumbar Burst Fractures.

OBJECTIVE: The prevalence of osteoporotic vertebral fractures has increased with aging populations, necessitating effective treatments such as percutaneous kyphoplasty combined with posterior screw fixation. However, biomechanical research on the effects of using short screws on fixation stability and bone stress or on the impact of bone cement bonding to screws on structural strength is lacking. This study aimed to optimize short-segment fixation strategies for osteoporotic thoracolumbar burst fractures by analyzing the biomechanical effects of pedicle screw length and bone-cement augmentation. METHODS: Four models of the thoracolumbar spine were established using computed tomography data of a female volunteer: (1) short screws in the injured vertebra without contact with the bone cement, (2) long screws without contact with the bone cement, (3) long screws in contact with the bone cement; and (4) long screws without the bone cement. The four fixation models were simulated under physiological loads. The range of motion, implant stress, and segmental stability were assessed. RESULTS: The three groups containing the bone cement exhibited similar performances in terms of stability and stress distribution, whereas the group without the bone cement exhibited a poorer biomechanical performance. Incorporation of the bone cement enhanced the biomechanical properties of the structure, and short screws in the injured vertebra without contact with the bone cement did not significantly compromise the biomechanical performance. CONCLUSION: Short screws in injured vertebrae without contact with the bone cement can achieve satisfactory stability and stress distribution. It is feasible to implant short screws in the injured vertebrae, reduce the number of bilaterally injured vertebrae, and inject bone cement through the non-pedicle approach during the surgical procedure, which simplifies the surgical process.

Deferoxamine Accelerates Mandibular Condylar Neck Fracture Early Bone Healing by Promoting Type H Vessel Proliferation.

BACKGROUND: Condylar fractures (CFs) are a common type of maxillofacial trauma, especially in adolescents. Conservative treatment of CF avoids the possible complications of surgical intervention, but prolongs the patient's suffering because of the requirement for extended intermaxillary fixation. Therefore, the development of a new strategy to accelerate the rate of fracture healing to shorten the period of conservative treatment is of great clinical importance. OBJECTIVE: To investigate the potential of deferoxamine (DFO) in promoting the healing process of CF in adolescent mice. METHODS: Thirty-two 4-week-old male C57BL/6J mice were randomly assigned to four groups: vehicle + sham group, vehicle + CF group, DFO + sham group and DFO + CF group. After constructing the mandibular CF model, mandibular tissue samples were collected respectively at 1, 2 and 4 weeks postoperatively. Radiographic and histomorphometric analyses were employed to assess bone tissue healing and vascular formation. RESULTS: Deferoxamine was observed to promote the early bone healing of fracture, both radiologically and histomorphometrically. Furthermore, this enhancement of condylar neck fracture healing was attributed to the upregulation of the hypoxia-inducible factor-1α (HIF-1α) signalling pathway while facilitating the formation of type H vessels. In addition, DFO did not produce significant effects on the condylar neck between vehicle + sham and DFO + sham group. CONCLUSION: The application of the HIF-1α inducer DFO can enhance type H vessels expansion thereby accelerating condylar neck fracture healing.

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

AIM AND BACKGROUND: This systematic review examined the current literature to evaluate the fracture resistance of the tooth fragments reattached using fiber-reinforced composites (FRC). MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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. CLINICAL SIGNIFICANCE: 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.

Static Loading of Different Intraradicular Preparation Depths of Trinia Endocrowns in Maxillary Canines.

AIM: The aim of this study is to compare the fracture resistance of canine teeth restored using TRINIA Endocrowns with three different types of preparations (2, 3, and 4 intracanal preparations). MATERIALS AND METHODS: Thirty maxillary-extracted canines were collected. All teeth were fixed in orthodontic acrylic resin and decapitated at the level of the proximal cemento-enamel junction (CEJ). After being endodontically treated, specimens were distributed equally between 3 groups (n = 10) with different preparation depths (GT: 2 mm Intraradicular Preparation, GH: 3 mm Intraradicular Preparation, GF: 4 mm Intraradicular Preparation). Thirty TRINIA endocrowns were dry milled. After surface treatment, all endocrowns were bonded to their corresponding roots using Permaflo a dual-cure resin cement. Each specimen was then fixed in the lower part of a universal testing machine with a load cell of 5 KN, at an angle of 45 degrees to the tooth long-axis at 0.5 mm/min crosshead speed. Failure loads were recorded in Newton's. Data were recorded, organized, and statistically investigated. RESULTS: Shapiro-Wilk tests revealed that the data were not normally distributed. Descriptive statistics revealed a high mean fracture resistance of GH (647 N), then GT (475.6 N), and finally GF (353.9 N). The Kruskal-Wallis test revealed a significant difference that existed between the groups being studied (p = 0.036). CONCLUSION: TRINIA endocrowns with intracanal preparations of 2 and 3 mm provide more promising fracture resistance than those with intracanal preparations of 4 mm as a way of treating of root-canal-treated maxillary canines. TRINIA endocrowns (2 and 3 mm intracanal preparations) are as promising as fiber posts and all ceramic crowns in terms of fracture resistance. TRINIA endocrowns with 2 mm intracanal preparations are mostly reparable after failure, but those of 3 and 4 mm are mostly irreparable after failure. CLINICAL SIGNIFICANCE: Modifying endocrowns to have intraradicular projections, simulating Nayyar core, may improve the success and longevity of endocrowns in anterior teeth. How to cite this article: Alahmad AM, Alenezi AY, Rayyan M, et al. Static Loading of Different Intraradicular Preparation Depths of Trinia Endocrowns in Maxillary Canines. J Contemp Dent Pract 2024;25(6):575-580.

Incidence and risk factors for limb fracture in greyhound racing in Western Australia.

Identification of risk factors for race day injury can improve greyhound welfare. Race day fractures are the most significant injury event and have the greatest negative impact on dog welfare and the industry's social license to operate. This study aimed to describe the incidence and risk factors for race-related fractures in greyhounds racing in Western Australia. Electronic extracts describing race level data and race day injuries were provided by Racing and Wagering Western Australia (RWWA). The incidence rate (IR) of fractures for all greyhound race starts in Western Australia from 1 January 2017-31/12/2023 was calculated per 1000 starts. Univariable and multivariable models using Poisson regression were used to calculate the IR ratio of fracture type based on race and greyhound-level factors. There were 198,008 racing starts and 662 (n = 643, 97.1% involving the limbs) fractures resulting in an IR of 3.3 fractures per 1000 starts (95%CI 3.1-3.6). Greyhounds that had an injury in their previous race were 2.3 times (95%CI1.4-4.3) more likely to have a forelimb fracture than greyhounds that did not have an injury (P = 0.013). The risk of tarsal bone fracture was greater in greyhounds older than 30 months and greyhounds that had not raced in the previous 15 days. Risk factors for fractures in the forelimb were associated with trauma after interference or dog collisions, whereas tarsal fractures were associated with strain and cyclic loading from race training/racing. Changes to racing structure, rules and policies based on these risk factors may help to reduce fracture incidence in racing greyhounds.