Ballistic long bone fracture pattern: an experimental study.

When dealing with badly preserved cadavers or skeletal human remains, the assessment of death circumstances remains challenging. When forensic evidence cannot be taken from the skin and soft tissue, the information may only be deduced from more resistant elements such as bone. Compared to cranial gunshot injuries, reliable data on ballistic long bone trauma remains scarce. This study aims to define ballistic fracture characteristics in human long bones. The shaft of 16 femurs and 13 humeri from body donors was perpendicularly shot with a 9-mm Luger full metal jacket bullet at an impact velocity of 360 m/s from a distance of 2 m. Some bones were embedded in Clear Ballistics Gel®, and some were shot without soft tissue simulant in order to better visualise the fracture propagation on the high-speed camera. The fractures were examined macroscopically and compared between the sample groups. We consistently found comminuted fractures with a stellate pattern. Fracture details were classified into entrance, exit and general characteristics. For some traits, we detected different occurrence values in the group comparison. The results indicate that some of the traits depend on bone properties such as shaft diameter, bone length and cortical thickness. The presence of ballistic gel also influenced some fracture traits, emphasising the relevance of soft tissue simulant in osseous gunshot experiments. This study revealed new insights in the detailed fracture pattern of human long bones. These may serve as guidelines for the identification and reconstruction of gunshot trauma in human long bones.

Epidemiological trends and mid-term to long-term outcomes of acetabular fractures in the elderly in China.

PURPOSE: To explore the epidemiological trends in acetabular fracture and report the mid-term to long-term clinical outcomes of the elderly treated with operation. METHODS: Retrospective study. Patients aged ≥ 14 years with operative treatment of the Acetabular fracture from Jan 2010 to Dec 2019 at a level-1 trauma centre were identified to analyze the epidemiological trends, and the difference in fracture patterns between young and elderly patients (≥ 60 years old) were compared. The elderly patients were followed up to evaluate their clinical outcomes and satisfaction degree (worst to best: 0 to10). The patients were divided into the 2010-2014 group and the 2015-2019 group according to the year of admission, and the clinical outcomes of the two groups were compared to verify the stability from mid-term to long-term after surgery for acetabular fracture. RESULTS: A total of 1024 patients (mean age 43.35 years, range 14-86 years) with acetabular fractures received operative treatment in this decade. The mean age of the acetabular fracture patients increased from 41.1 years to 47.7 years, and the proportion of elderly patients increased from 5.7% to 24.0%, with some volatility. The ratio of male to female decreased year by year, and the proportion of female patients increased with age. And the anterior fracture patterns were more common in the elderly patients compared to the young patients (P < 0.001). 118 elderly patients (82 males, 36 females; mean age 66.91 years, range 60-86 years) were followed-up (mean 77.4 months, range 35-152 months). The overall mortality rate of the elderly patients was 7.69% (9/118). The Harris hip score of those alive patients was 90.41 ± 12.91 points (excellent and good rate 84.4%). 87 patients completed the SF-12 with a normal HRQoL (PCS 50.49 ± 8.88 points; MCS 55.66 ± 8.86 points). 90.8% of the patients achieved a satisfaction score of 9 or higher. And there was no significant difference in clinical outcomes between the 2010-2014 group and the 2015-2019 group (P > 0.05). CONCLUSIONS: In conclusion, acetabular fractures presented an obvious ageing trend in China, and the fracture patterns of the elderly patients differed from those in the young patients. Operative treatment for elderly acetabular fractures yielded satisfactory and persistent clinical outcomes from mid-term to long-term clinical.

Is radiological rotation measurement affected by the fracture pattern in pediatric supracondylar humeral fractures?

BACKGROUND: In supracondylar humerus fractures (SCHF), the most frequently used method to calculate rotation is the Gordon lateral rotation percentage (GLRP) defined by Gordon et al. However, this technique includes only typical fractures (49%-80% of all fractures) from the Johns Hopkins (J-H) fracture classification system. PURPOSE: The aim of the study was to investigate (1) is Gordon criteria useful for John Hopkins subgroups of supracondylar fractures and (2) is Gordon criteria affected by internal and external rotation. MATERIAL AND METHODS: This study was designed using four pediatric left humerus bones obtained from the Sawbone© company. For each bone, an osteotomy was made to mimic each of the J-H coronal fracture patterns. The cut bones were placed in a wooden rotation apparatus. The GLRP measurements were taken by five blinded observers. RESULTS: In the repeated measurements of the observers, <20° rotation typical and <30° medial oblique and lateral oblique fracture pattern were measured as within the limits of an acceptable amount of rotation according to the Gordon criteria. However, for high fracture pattern (HFP), ≤30° internal rotation and <60° external rotation were determined to be within the acceptable rotation criteria according to the Gordon criteria. CONCLUSIONS: All fracture patterns have different characteristics; however, based on the data of this study, the Gordon criteria can be used safely for typical, medial oblique, and lateral oblique fracture patterns but it is necessary to lower the acceptable rate of 50% for HFP.

Predicting the deltoid tuberosity index in proximal humerus fractures using fracture characteristics and patient age: development of the LBQ-PHF score.

BACKGROUND: The aim of this study was to investigate (1) whether fracture pattern and age are associated with local bone quality (LBQ), and (2) whether a scoring system based on these variables is able to predict LBQ in proximal humerus fractures (PHF). MATERIALS AND METHODS: A retrospective study was performed of all acute PHF at a Level 2 trauma center with plain radiographs and CT between June 2009 and March 2022. Local bone quality was measured by using the deltoid tuberosity index (DTI). In addition to age and gender, fracture morphology was categorized using the following classification systems: Neer, Resch, AO Foundation/Orthopaedic Trauma Association (AO/OTA), and Hertel/LEGO. Additionally, coronal head alignment was calculated by measuring the head-shaft angle. RESULTS: Only the Resch classification system revealed a significant relationship between fracture type and bone quality, as there was a significant association between coronal head alignment and DTI (p = 0.001). Valgus head alignment was observed significantly more frequent in patients with low bone quality (p = 0.002). Multinomial logistic regression analysis revealed a significant relative risk ratio for age (RRR = 0.97, [95% CI, 0.94-1], p = 0.039) and a non-significant trend for DTI (RRR = 1.26, [95% CI, 0.96-1.64], p = 0.092) for occurrence of anatomic relative to valgus head alignment. Using a DTI cut-off value of 1.3 instead of 1.4, age and also varus head alignment were identified as significant predictors of LBQ (OR = 1.12, [95% CI, 1.1-1.15], p < 0.001; OR = 0.54, [95% CI, 0.3-0.96], p = 0.037). A scoring system called the LBQ-PHF score (local bone quality in proximal humerus fractures), developed based on these two variables was able to predict LBQ with a sensitivity of 79.2% and a specificity of 86.7%. CONCLUSION: Age and coronal humeral head alignment are independent predictors of LBQ in PHF. A simple scoring system developed based on these variables is able to assess BQ with solid predictive characteristics.

Fracture line and comminution zone characteristics, and rotator cuff footprint involvement in OTA/AO 11C3-type proximal humeral fractures: complex proximal humerus fracture map.

PURPOSE: To identify fracture characteristics and zones of comminution as well as the relationship with anatomic landmarks and rotator cuff footprint involvement in OTA/AO 11C3-type proximal humerus fractures. METHODS: Computed tomography images of 201 OTA/AO 11C3 fractures were included. Fracture lines were superimposed to a 3D proximal humerus template, created from a healthy right humerus, after fracture fragment reduction on 3D reconstruction images. Rotator cuff tendon footprints were marked on the template. Lateral, anterior, posterior, medial, and superior views were captured for the interpretation of fracture line and comminution zone distribution as well as to define the relationship with anatomic landmarks and rotator cuff tendon footprints. RESULTS: A total of 106 females and 95 males (mean age = 57.5 ± 17.7 [range 18-101] years) with 103 C3.1-, 45 C3.2-, and 53 C3.3-type fractures were included. On the lateral, medial, and superior humeral surfaces, fracture lines and comminution zones were distributed differently in 3 groups. Tuberculum minus and medial calcar region were significantly less severely affected in C3.1 and C3.2 fractures than C3.3 fractures. The supraspinatus footprint was the most severely affected rotator cuff footprint area. CONCLUSIONS: Specifically defining the certain differences for repeatable fracture patterns and comminution zones in OTA/AO 11C3-type fractures and the relationship between the rotator cuff footprint and the joint capsule may contribute to the decision-making process of surgeons.

Effects of screw channel angulation on the fracture resistance of one-piece zirconia crown with titanium base.

PURPOSE: The design of the angulated screw channel in implant restorations allows the possibility to correct angulation discrepancies, especially in the anterior maxilla. However, the effects of varied screw channel angulations on fracture resistances and fracture patterns of the implant restorations are still uncertain, and thus the aim of this study. MATERIALS AND METHODS: Angulated screw channel monolithic zirconia crowns (Nobel Biocare) with three different angulation groups-straight (ASC1), 15° (ASC15), and 25° (ASC25)-were digitally designed from a left central incisor prototype scan. Following fabrication, 10 samples of each group were individually mounted onto implant replicas embedded in standardized type V stone gypsum cylinder jigs (25 mm × 25 mm). All screws were manually torqued to 35 Ncm according to the manufacturer's recommendation, and screw access openings were subsequently sealed with resin composite. To mimic the off-axis loading of the central incisor, the specimens were then loaded at a cephalometric interincisal relationship of 135° between the long axis of the crown and the Instron force applicator, with crosshead speed set at 0.5 mm/min. Fractured abutment surfaces were examined, and selected specimens were further evaluated by scanning electron microscopy. Screw torque values were also measured after the catastrophic loading. One-way ANOVA was used to compare load-to-fracture values between groups, with the statistical significance set at 0.05 (p values). RESULTS: The mean load-to-fracture values in descending order were 331.24N (±34.00N) in ASC15, 325.22N (±35.50N) in ASC25, and 302.04N (±45.10N) in ASC1, with no statistically significant differences between groups. Considerable screw torque losses were found in all groups after catastrophically loading. The average torque loss was 84% in ASC1, 86% in ASC15, and 94% in ASC25. 16 out of 30 specimens experienced screw loosening; one ASC1 screw underwent slight deformation. Crowns of all tested groups exhibited cohesive fracture patterns at the screw-metallic-zirconia interfaces. CONCLUSIONS: Within the limitations of this in vitro study, one-piece monolithic zirconia implant crowns with varied screw channel angulations shared similar fracture-strength and fracture-mode characteristics. The zirconia-titanium base junctions exhibited the weakest link of all restorations.

The influence of horizontal glass fiber posts on fracture strength and fracture pattern of endodontically treated teeth: A systematic review and meta-analysis of in vitro studies.

PURPOSE: This systematic review and meta-analysis aimed to summarize available evidence regarding the effect of horizontal glass fiber posts (HGFPs) on fracture strength and fracture pattern of endodontically treated teeth (ETT) compared to controls without HGFP. The review protocol was registered on the OSF registries. METHODS: Literature searches were conducted in MEDLINE/PubMed, Scopus, Web of Science, Embase, Google Scholar, and ProQuest for all relevant studies published up to February 2022. All in vitro studies that assessed the influence of HGFPs on fracture strength and fracture pattern of ETT whether mesio-occluso-distal or mesio-occlusal or DO cavities were considered eligible. Review Manager (RevMan) was used for the meta-analysis. Subgroup and funnel plot analyses were also performed. Quality assessment was conducted by two independent reviewers. RESULTS: A total of 12 articles met the inclusion criteria, and 10 studies underwent quantitative evaluation. The pooled effect showed that fracture resistance of molar teeth restored with HGFP was significantly higher than teeth without HGFP (standardized mean difference [SMD]: 1.61, 95% confidence interval [CI]: 0.14, 3.09, p = 0.03), whereas marginally significant for premolars (SMD: 1.36, 95% CI: -0.00, 2.73, p = 0.05). Regarding fracture patterns, the presence of an HGFP significantly increased the occurrence of restorable fracture patterns for premolars (odds ratios [OR]: 4.15, 95% CI: 1.60, 10.82, p = 0.004) compared to controls, whereas the difference was not significant for molars (OR: 1.09, 95% CI: 0.43, 2.77, p = 0.85). Moderate risk of bias was identified in 9/12 studies; one study showed a high risk of bias and two studies showed a low risk of bias. CONCLUSIONS: Within the limitations of this study, there is evidence from in vitro studies that the use of HGFP increases the fracture resistance of the ETT when compared to teeth without HGFP and also reduces the occurrence of non-restorable fractures for premolars. However, well-conducted in vitro and prospective clinical studies are warranted to validate this finding.

The pattern of incident fractures according to fracture site in people with T1D.

Higher incidences of fractures are seen in people with type 1 diabetes (T1D), but knowledge on different fracture sites is sparse. We found a higher incidence mainly for distal fracture sites in people with T1D compared to controls. It must be further studied which fractures attributed to the higher incidence rates (IRs) at specific sites. INTRODUCTION: People with T1D have a higher incidence of fractures compared to the general population. However, sparse knowledge exists on the incidence rates of individual fracture sites. Therefore, we examined the incidence of various fracture sites in people with newly treated T1D compared to matched controls. METHODS: All people from the UK Clinical Practice Research Datalink GOLD (1987-2017), of all ages with a T1D diagnosis code (n = 6381), were included. People with T1D were matched by year of birth, sex, and practice to controls (n = 6381). Fracture IRs and incidence rate ratios (IRRs) were calculated. Analyses were stratified by fracture site and sex. RESULTS: The IR of all fractures was significantly higher in people with T1D compared to controls (IRR: 1.39 (CI95%: 1.24-1.55)). Compared to controls, the IRR for people with T1D was higher for several fracture sites including carpal (IRR: 1.41 (CI95%: 1.14-1.75)), clavicle (IRR: 2.10 (CI95%: 1.18-3.74)), foot (IRR: 1.70 (CI95%: 1.23-2.36)), humerus (IRR: 1.46 (CI95%: 1.04-2.05)), and tibia/fibula (IRR: 1.67 CI95%: 1.08-2.59)). In women with T1D, higher IRs were seen at the ankle (IRR: 2.25 (CI95%: 1.10-4.56)) and foot (IRR: 2.11 (CI95%: 1.27-3.50)), whereas in men with T1D, higher IRs were seen for carpal (IRR: 1.45 (CI95%: 1.14-1.86)), clavicle (IRR: 2.13 (CI95%: 1.13-4.02)), and humerus (IRR: 1.77 (CI95%: 1.10-2.83)) fractures. CONCLUSION: The incidence of carpal, clavicle, foot, humerus, and tibia/fibula fractures was higher in newly treated T1D, but there was no difference at other fracture sites compared to controls. Therefore, the higher incidence of fractures in newly treated people with T1D has been found mainly for distal fracture sites.

Risk Factors Analysis for Different Types of Unfavorable Fracture Patterns During Sagittal Split Ramus Osteotomy: A Retrospective Study of 2008 Sides.

PURPOSE: To summarize unfavorable fracture patterns during sagittal split ramus osteotomy (SSRO) and investigate the association with influencing factors. MATERIALS AND METHODS: We conducted a retrospective analysis of 1007 patients with 2008 sides of SSRO and classified unfavorable fracture patterns into three types: fracture lines involving the sigmoid notch, condylar process, or coronoid process (Type A); fracture lines extending from the posterior border of the mandibular ramus to the mandibular body or the anterior border of the ramus (Type B); and unfavorable fractures located in the anterior horn of the proximal segment with free fragment (Type C). Logistic regression analysis was used to evaluate factors influencing unfavorable fracture patterns, including sex, age at the time of operation, class of occlusion, presence of the third molar, uni- or bi-maxillary surgery, and the distance from the mandibular canal to the buccal cortex. RESULTS: The distance from the mandibular canal to the buccal cortex was significantly associated with unfavorable fracture patterns during SSRO. The presence of third molars was significantly associated with Type A fractures. The distance from the mandibular canal to the buccal cortex was significantly lower in Type B fractures. CONCLUSION: We found that the influencing factors for unfavorable fracture patterns varied. Clinicians should pay specific attention to patients with factors for each unfavorable fracture pattern during SSRO. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Could different direct restoration techniques affect interfacial gap and fracture resistance of endodontically treated anterior teeth?

OBJECTIVES: To evaluate different direct restoration techniques on various cavity designs in anterior endodontically treated teeth (ETT). MATERIALS AND METHODS: Ninety upper central incisors (n = 90) were selected, endodontically treated, and divided into three groups (n = 30) accordingly to the cavity design: minimal endodontic cavity access (group A), endodontic access + mesial class III cavity (group B), and endodontic access + two class III cavities (group C). Three subgroups (n = 10) were then created accordingly to the restoration technique: nano hybrid composite restoration (subgroup a), glass fiber post + dual-cure luting cement (subgroup b), and bundled glass fiber + dual-cure luting cement (subgroup c). Samples underwent micro-CT scan, chewing simulation, and a second micro-CT scan. 3D quantification (mm3) of interfacial gap progression was performed; then, samples underwent fracture resistance test. Data were statistically analyzed setting significance at p < 0.05. RESULTS: Groups A and B showed significantly lower interfacial gap progression compared with group C. Subgroup b performed significantly better compared with subgroups a and c. Improved fracture strength was reported for group C compared with group A, while both subgroups b and c performed better than subgroup a. CONCLUSIONS: Cavity design significantly influenced interfacial gap progression and fracture resistance. Fiber posts significantly lowered gap progression and improved fracture resistance while bundled fibers only increased fracture resistance. A significant reduction of non-repairable fractures was recorded when fibers were applied. CLINICAL RELEVANCE: A minimally invasive approach, conserving marginal crests, should be applied whenever possible. Inserting a fiber post is indicated when restoring anterior ETT, in order to reduce gap progression, improve fracture resistance, and avoid catastrophic failures.

Biomechanics of a cemented short stem: a comparative in vitro study regarding primary stability and maximum fracture load.

PURPOSE: In total hip arthroplasty, uncemented short stems have been used more and more frequently in recent years. Especially for short and curved femoral implants, bone-preserving and soft tissue-sparing properties are postulated. However, indication is limited to sufficient bone quality. At present, there are no curved short stems available which are based on cemented fixation. METHODS: In this in vitro study, primary stability and maximum fracture load of a newly developed cemented short-stem implant was evaluated in comparison to an already well-established cemented conventional straight stem using six pairs of human cadaver femurs with minor bone quality. Primary stability, including reversible micromotion and irreversible migration, was assessed in a dynamic material-testing machine. Furthermore, a subsequent load-to-failure test revealed the periprosthetic fracture characteristics. RESULTS: Reversible and irreversible micromotions showed no statistical difference between the two investigated stems. All short stems fractured under maximum load according to Vancouver type B3, whereas 4 out of 6 conventional stems suffered a periprosthetic fracture according to Vancouver type C. Mean fracture load of the short stems was 3062 N versus 3160 N for the conventional stems (p = 0.84). CONCLUSION: Primary stability of the cemented short stem was not negatively influenced compared to the cemented conventional stem and no significant difference in fracture load was observed. However, a clear difference in the fracture pattern has been identified.

Proximal humeral fracture morphology in patients with advanced cuff tear arthropathy: an observational study in a surgically treated cohort.

BACKGROUND: In the presence of cuff tear arthropathy (CTA), joint kinematics is alternated and fracture configuration might be different. The purpose of this study was to identify fracture patterns in patients with advanced CTA to facilitate recognition and treatment. METHODS: Radiographs and computed tomography scans of all patients undergoing surgical treatment for a proximal humeral fracture (PHF) in our institution during a 5-year period were retrospectively analyzed. Fracture pattern according to the AO-OTA and Resch classification and the presence of CTA were evaluated. Glenoid configuration according to Walch, fatty atrophy of the supraspinatus muscle and the centrum-collum-diaphyseal (CCD) angle were analyzed. RESULTS: A total of 574 out of 713 patients were included. Twenty-three patients (4%) with a mean age of 82 ± 8 years showed advanced CTA with acetabularization of the acromion (≥ stage 3 according to Hamada/Fukuda). There were exclusively valgus fractures with a mean CCD angle of 158° ± 18°. Patients with CTA ≥ grade 3 had a nearly twofold greater risk (risk ratio: 1.8; confidence interval (CI): 95% 1.6-1.9; p < 0.0001) of sustaining a valgus fracture compared to patients without or with CTA < grade 3. The risk for a tuberosity fracture was nearly twofold greater in patients without or with mild CTA (risk ratio: 1.68; confidence interval (CI): 95% 1.17-2.40; p = 0.0046) compared to those with advanced CTA. CONCLUSION: In advanced CTA, a predominantly valgus fracture pattern can be observed. In addition, fractures of the greater tuberosity were significantly less frequent and were rarely displaced. Up to date, no classification system for PHF has been developed in the setting of CTA although it might indicate a different treatment, and therefore, recognition is crucial. However, when present, this changes the fracture pattern and ability to treat the fracture as the rotator cuff can no longer be utilized as a means of reducing the fragments.

How Does Mechanism of Injury Relate to Similar Fracture Patterns in Bilateral Displaced Intra-articular Calcaneal Fractures?

Several biomechanical/cadaver studies have established a correlation between mechanism of injury and fracture classification in calcaneal fractures. However, this has never been backed up by clinical studies. In this study, the hypothesis is tested whether the alleged similar mechanism of injury for both feet in bilateral calcaneal fractures leads to similar fracture types. In this retrospective cross-sectional cohort study, patients with unilateral and bilateral calcaneal fractures treated between 2000 and 2017 were classified according to Essex-Lopresti and Sanders. Positive predictive values were computed, signifying the chance that the fracture type in the left foot corresponded to that in the right foot. These were compared to the a priori chance of a fracture type (percentage of fracture type in unilateral fractures) by constructing 95% confidence intervals of the positive predictive value of each fracture type. Of the 451 patients, 413 (91.6%) had unilateral and 38 (8.4%) bilateral calcaneal fractures. Mechanisms of injury were similar for uni- and bilateral fractures. Using the Essex-Lopresti fracture classification, 34 cases (90%) had the same classification in both feet, compared with 24 (63%) in the Sanders classification. The chance of a fracture type in the left, with the right foot as reference, was significantly larger than expected from a priori chance in the unilateral population. This leads to a new hypothesis, that, more than mechanism of injury, the magnitude of the impact and the position of the foot are important in predicting fracture classification in the calcaneus.

The dominant nutrient foramen at the clavicular midshaft: an anatomical study.

BACKGROUND: The aim of the present study was to describe the prevalence and topography of the dominant nutrient foramen at the clavicle. METHODS: 317 macerated human clavicles (167 right and 150 left) were available for the study. After detecting the dominant nutrient foramen, the total distance from the sternal surface to the examined nutrient foramen was measured. A foramen index (FI) was used for further data processing. RESULTS: We detected a dominant foramen in 300/317 (94.64%) clavicles, which was located in the middle third in 287/300 (95.7%) clavicles. The average clavicular length was measured at 14.9 cm ± 1.0 cm (range 11.6-17.5 cm) with an average foraminal distance from the sternoclavicular joint surface of 7.9 cm ± 1.3 cm (range 0.9-12.6 cm) in total. The mean FI was 53.2% ± SD 7.4% (range 5.5-79.3%). CONCLUSION: The present study provides a topographic mapping of the foraminal area (46-60% of the total clavicular length). The findings help to assess clavicular fracture patterns, which pass through the foraminal area.

Adult distal humerus trauma with surgical intervention: CT analysis of fracture pattern, causes, and distribution.

This multicenter cross-sectional study aimed to determine the differences in distribution and fracture pattern between low-energy and high-energy groups in distal humeral fractures in Japan. Retrospectively, 133 patients (48 males, 85 females) with distal humeral fractures were enrolled in this study. The age, sex, fracture classification, injury mechanism, preoperative therapy for osteoporosis, and nature of soft-tissue injury were recorded for all patients. The Mann-Whitney U test and chi-square test or Fisher's exact test were used for non-normally distributed variables and categorical variables, respectively, to compare differences between the two groups. The mean age of the patients at the time of surgery was 66 years (range 21-99 years). Marked differences were observed between the two groups in terms of age, sex, and fracture pattern. The mean age of patients with AO classification type A2 fractures was significantly higher than that of the patients with other fracture types. In contrast, the mean age of patients with AO classification type C2 fractures was slightly lower than that of the remainder of the population. In the low-energy trauma group, females accounted for 72.2% of fractures and their mean age at the time of surgery was 76 years. Low-energy trauma among elderly individuals was prominent.

Fatal falls involving stairs: an anthropological analysis of skeletal trauma.

The skeletal blunt force trauma resulting from fatal falls involving stairs is complex. There are countless ways an individual may fall when stairs are involved, and thus a variety of ways the skeleton may fracture. Therefore anecdotally, it may be said that there is no specific skeletal trauma characteristic of this fall type. In order to scientifically investigate this anecdotal understanding, this study provides a detailed investigation of the skeletal fracture patterns and morphologies resulting from fatal falls involving stairs. Skeletal trauma was analyzed using the full-body postmortem computed tomography scans of 57 individuals who died from a fall involving stairs. Trauma was examined in the context of the variables that potentially influence how an individual falls (i.e. sex, age, body mass index, number of stairs involved, psychoactive drugs, pre-existing conditions, landing surface and manner of the fall) using logistic regression. Skeletal trauma primarily occurred in the axial skeleton. An analysis of fracture patterns showed the cranial base was less likely to fracture in younger individuals and the cervical vertebrae were more likely to fracture in falls that involved more than half a flight of stairs. A total of 56 fracture morphologies were identified. Of these, diastatic fractures were less likely to occur in older individuals. Findings indicate that there are skeletal fracture patterns and morphologies characteristic of a fatal fall involving stairs.

Influence of Fatigue Loading and Bone Turnover on Bone Strength and Pattern of Experimental Fractures of the Tibia in Mice.

Bone fragility depends on bone mass, structure, and material properties, including damage. The relationship between bone turnover, fatigue damage, and the pattern and location of fractures, however, remains poorly understood. We examined these factors and their integrated effects on fracture strength and patterns in tibia. Adult male mice received RANKL (2 mg/kg/day), OPG-Fc (5 mg/kg 2×/week), or vehicle (Veh) 2 days prior to fatigue loading of one tibia by in vivo axial compression, with treatments continuing up to 28 more days. One day post fatigue, crack density was similarly increased in fatigued tibiae from all treatment groups. After 28 days, the RANKL group exhibited reduced bone mass and increased crack density, resulting in reduced bone strength, while the OPG-Fc group had greater bone mass and bone strength. Injury repair altered the pattern and location of fractures created by ex vivo destructive testing, with fractures occurring more proximally and obliquely relative to non-fatigued tibia. A similar pattern was observed in both non-fatigued and fatigued tibia of RANKL. In contrast, OPG-Fc prevented this fatigue-related shift in fracture pattern by maintaining fractures more distal and transverse. Correlation analysis showed that bone strength was predominantly determined by aBMD with minor contributions from structure and intrinsic strength as measured by nanoindentation and cracks density. In contrast, fracture location was predicted equally by aBMD, crack density and intrinsic modulus. The data suggest that not only bone strength but also the fracture pattern depends on previous damage and the effects of bone turnover on bone mass and structure. These observations may be relevant to further understand the mechanisms contributing to fracture pattern in long bone with different levels of bone remodeling, including atypical femur fracture.

Fracture pattern analysis of fractures to the diaphysis of the fifth metatarsal.

BACKGROUND: Fractures to the fifth's metatarsal (MT-V) diaphysis are common. These are inconsistently referred to as diaphyseal-, shaft-, or Dancer's fractures. A comprehensive analysis of the MT-V fracture morphology is missing. The aim was to qualitatively and quantitatively analyze fracture patterns of MT-V diaphyseal fractures. HYPOTHESIS: Fractures to the shaft of the fifth metatarsal feature specific fracture morphologies. MATERIALS AND METHODS: Retrospective, radiologic database study. Included were all acute, isolated MT-V shaft fractures (including the proximal [Lawrence and Botte (L&B) III] and distal meta-diaphysis). Demographics and fracture characteristics were assessed. Each proximal fracture line was drawn, scaled, and a qualitative and quantitative fracture line analysis was conducted. The quantitative fracture line analysis aimed at identifying dens clusters with arbitrary shape using the DBSCAN algorithm. Data are presented as mean±standard deviation. RESULTS: Out of 704 eligible MT-V fractures, 156 met the inclusion criteria. Patient's mean age was 46±19 years and 94% suffered a low energy trauma. Qualitative and quantitative fracture line analysis revealed three distinct fracture patterns. The proximal (30%) and distal (5%) meta-diaphyseal clusters showed a predominant transverse fracture pattern. The vast majority of diaphyseal fractures (56%) were spiral/oblique fractures, progressing from the proximal lateral meta-diaphyseal region in an oblique course at 61±9° to the medial distal diaphyseal cortex. Seven percent of diaphyseal fractures showed a transverse fracture pattern. DISCUSSION: Based on a qualitative and quantitative analysis of all MT-V shaft fractures, three distinct fracture clusters were identified with homogeneous fracture patterns. MT-V shaft fractures should therefore be classified as proximal meta-diaphyseal (L&B Type III), diaphyseal (oblique or transverse) and distal meta-diaphyseal. LEVEL OF PROOF: IV; retrospective database study.

Unconventional mobility, conventional trauma: a comparative analysis of e-scooter-related fractures.

PURPOSE: The present research aimed to compare the different types of fractures to those caused by e-scooter use as well as reveal the severity of e-scooter injuries via an epidemiological analysis of fractures over the course of 6 months. METHODS: This retrospective study assessed medical records of patients with fractures or dislocations admitted to a Turkish level three trauma centre emergency orthopaedic department between June 2021 and January 2022. Using a two-group design, the first group encompassed all fractures and dislocations treated, while the second focused on e-scooter-related cases. Comparative analysis covered fracture patterns and factors within the e-scooter group, like demographics, injury mechanism, and timing. Surgical need and types were explored for e-scooter injuries. RESULTS: Among 4481 upper extremity fractures, finger fractures (27.47%) and distal radius fractures (25.37%) were common, while e-scooter-related cases exhibited radius and ulna shaft fractures (23.07%). Of 2400 lower extremity fractures, toe fractures (30.2%) and metatarsal fractures (19.66%) predominated, with e-scooter-related injuries largely featuring metatarsal fractures (30%). The surgery rate in all patients was 8.92%, whereas the surgery rate specifically for e-scooter injuries was 48.2%. Significantly greater occurrence of lower extremity fractures was evident in e-scooter-related injuries compared to upper extremities (p = 0.011). Collisions involving stationary or moving objects were linked to injuries in the lower extremities, whereas falls were primarily associated with injuries in the upper extremities. Treatment included surgery (48.2%) and conservative management (52.8%), with ORIF (35.7%) and CRIF (10.7%) utilised. CONCLUSION: E-scooter-related fractures and dislocations are typically more severe, often requiring surgery, compared to other fractures during the same period. The study emphasises the link between injury type and increased risk of lower extremity fractures or dislocations.

Exploring Fracture Patterns: Assessing Representation Methods for Bone Fracture Simulation.

Fracture pattern acquisition and representation in human bones play a crucial role in medical simulation, diagnostics, and treatment planning. This article presents a comprehensive review of methodologies employed in acquiring and representing bone fracture patterns. Several techniques, including segmentation algorithms, curvature analysis, and deep learning-based approaches, are reviewed to determine their effectiveness in accurately identifying fracture zones. Additionally, diverse methods for representing fracture patterns are evaluated. The challenges inherent in detecting accurate fracture zones from medical images, the complexities arising from multifragmentary fractures, and the need to automate fracture reduction processes are elucidated. A detailed analysis of the suitability of each representation method for specific medical applications, such as simulation systems, surgical interventions, and educational purposes, is provided. The study explores insights from a broad spectrum of research articles, encompassing diverse methodologies and perspectives. This review elucidates potential directions for future research and contributes to advancements in comprehending the acquisition and representation of fracture patterns in human bone.