Expanding bullets and ballistic gelatin - A restricted expansion experiment.

Ballistic gelatin has gained a status as standard method for terminal ballistic testing and experimenting. Variation considering the recipe and manufacturing of the blocks exists. The golden standard has been a cuboid gelatin block, dimensions varying according to the type and kinetic energy of the ammunition. Powerful ammunition requires larger gelatin blocks, making their handling and manufacturing difficult. This is the case especially with powerful, expanding hunting ammunition that leave most of their kinetic energy within the gelatin block. High speed cameras reveal that blocks tend to expand or swell significantly and even travel upon impact, potentially affecting to some basic values of terminal ballistics such as cavitation and energy transfer. In this study, we wanted to experiment new method to study terminal ballistics of high power, expanding ammunition by using cylinder shaped gelatin blocks. Secondly, we used a plastic tube around the gelatin cylinder to restrict the expansion/swelling. Thirdly we attached our gelatin target to a sturdy platform to restrict the movement of the cylinder and potentially improve the energy transfer of the bullet into the gelatin. To conduct our study we compared our experimental setting with a traditional, cuboid gelatin block. After the test firing the blocks underwent computed tomography scanning with clinical equipment. Three-dimensional reconstructions of gelatin cavitation and bullet fragment deposition were created. Our results clearly demonstrate that the restricted expansion of the block also clearly restricts the cavitation inside the gelatin. We believe that the method can be further developed, and it allows better potential for ballistic testing of heavy ammunition. In addition, it may aid in terminal ballistic reconstruction of forensic cases with gunshot trauma in anatomical structures fully enclosed by connective tissue such as brain and structures of the thorax.

Association Between Cumulative G-force Exposure and Cervical Spine Degenerative Changes.

INTRODUCTION: Fighter pilots work in a unique environment and are subject to high G-force loads under simultaneous head movements. Neck pain is reported to be a common health problem among fighter pilots leading to time lost flying and flight duty limitations. The present study aimed to find out if differences in early military flight career G-force exposure levels could increase the risk for degenerative changes in the cervical spine. MATERIALS AND METHODS: The study population consisted of 56 20-year-old Finnish Air Force male fighter pilot cadets, who underwent MRI of the cervical spine at baseline and after 5 years. During follow-up, the G-force exposure was measured using the individual Fatigue Index (FI) recordings. The FI data were collected from each flight with BAE Hawks and is determined by the number of times certain levels of G-forces are exceeded during the flights. The incidence or progression of each degenerative change was compared to individual FI values using Pearson correlation coefficients. RESULTS: The pilots flew on average 220 (±21) hours with high performance aircraft during follow-up, resulting in an average FI of 1.98 (±0.47). A statistically significant progression was found in intervertebral disc (IVD) degeneration sum score with no correlation to corresponding FI values. A statistically significant increase was also found in the prevalence of IVD herniations with a negative correlation with FI values. Other degenerative cervical spine changes did not progress or did not correlate with corresponding FI values. CONCLUSIONS: The prevalence of IVD degeneration and IVD herniations increases in the early phases of fighter pilots' career. Only the incidence of IVD herniations correlated with FI values and the correlation was negative. The negative correlation may be attributed to avoidance behavior due to neck pain, which was not measured in our study, or other unmeasured confounding factors. This was the first study to compare individual G-force exposure levels to high-quality MRI data over a follow-up of several years. Finnish fighter pilots are known to report increasing cervical symptoms during the Hawk training phase, but longer follow-up periods are likely needed to determine the association between G-force exposure levels and cervical degenerative changes.

Three-dimensional visualization of gunshot cavities in ballistic gelatine with computed tomography - A forensic ballistics case study.

Three-dimensional (3D) imaging, primarily computed tomography (CT), has proven valuable in the documentation and analysis of gunshot injuries. Explicit visualization of findings may play a pivotal role in judicial settings. This forensic ballistics case study aimed to examine the potential of CT-based 3D reconstruction to digitally visualize gunshot cavities in ballistic gelatine. Three .30 caliber bullets of different types (full metal jacket, soft point, and expanding monolithic) were fired into standardized blocks of 10% ballistic gelatine. The blocks underwent CT scanning with clinical equipment. Gelatine and air were segmented from the CT data using an open-source software. 3D reconstruction views of the segmented gelatine and air components were created. The gunshot cavities were clearly observed in both gelatine and air segmentation. The differences in cavitation between bullet types were evident in both reconstruction approaches, although gelatine segmentation produced higher resolution of small details. The obvious benefit of digital reconstruction was the ability to freely tilt and rotate the 3D images, with the possibility of taking measurements manually or automatically from any plane. Moreover, all the data can be stored for future analysis. This study introduces a preliminary method for digital visualization and documentation of gunshot cavitation in ballistic gelatine, to be fine-tuned and implemented for research purposes and routine practice in forensic institutions.

Musket ball injuries to the head - Experimental CT-study.

A smoothbore musket firing a round ball was the primary weapon of the infantry from the 16th to mid 19th century. Musket ball injuries are thus relatively common when archaeological remains of battlefield victims from that period are studied. Several experimental studies have focused on terminal ballistics of a musket ball. In addition, there is a good supply of historical records directly from the battlefield and military hospitals. Studies and historical records have both concluded that head injuries are among the most lethal types of musket ball damage. In this study we utilized modern day research methods, including Synbone ballistic skull phantoms and computed tomography (CT) imaging, to examine more closely the head injuries and tissue damage caused by a musket ball. We were especially interested to observe how different musket ball velocities and shooting distances would influence bone and soft tissue defects. Our experiments clearly demonstrated that musket ball was a lethal projectile even from a longer distance. Already at low velocities, the musket ball perforated through the skull. Velocity also influenced the appearance of entrance and exit wounds. CT imaging provided us with a three-dimensional view of the wound channel, skull fragments and lead remnants inside the skull phantom. According to our findings, musket ball velocity influenced defect size and cavitation. In addition, velocity influenced the size and distribution of skull fragments and lead remnants in the wound channel. Combining all these aspects could aid us in studies of archaeological musket ball victims. In particular, they could help us to estimate the shooting distance and shed light on the potential course of events in the battlefield.

Financial impact of incorporating deep learning reconstruction into magnetic resonance imaging routine.

PURPOSE: Artificial intelligence and deep learning solutions are increasingly utilized in healthcare and radiology. The number of studies addressing their enhancement of productivity and monetary impact is, however, still limited. Our hospital has faced a need to enhance MRI scanner throughput, and we investigate the utility of new commercial deep learning reconstruction (DLR) algorithm for this purpose. In this work, a multidisciplinary team evaluated the impact of the widespread deployment of a new commercial deep learning reconstruction (DLR) algorithm for our magnetic resonance imaging scanner fleet. METHODS: Our analysis centers on the DLR algorithm's effects on patient throughput and investment costs, contrasting these with alternative strategies for capacity expansion-namely, acquiring additional MRI scanners and increasing device utilization on weekends. We provide a framework for assessing the financial implications of new technologies in a trial phase, aiding in informed decision-making for healthcare investments. RESULTS: We demonstrate substantial reductions in total operating costs compared to other capacity-enhancing methods. Specifically, the cost of adopting the deep learning technology for our entire scanner fleet is only 11 % compared to procuring an additional scanner and 20 % compared to the weekend utilization costs of existing devices. CONCLUSIONS: Procuring DLR for our existing five-scanner fleet allows us to sustain our current MRI service levels without the need for an additional scanner, thereby achieving considerable cost savings. These reductions highlight the efficiency and economic viability of DLR in optimizing MRI service delivery.

Clinical Super-Resolution Computed Tomography of Bone Microstructure: Application in Musculoskeletal and Dental Imaging.

PURPOSE: Clinical cone-beam computed tomography (CBCT) devices are limited to imaging features of half a millimeter in size and cannot quantify the tissue microstructure. We demonstrate a robust deep-learning method for enhancing clinical CT images, only requiring a limited set of easy-to-acquire training data. METHODS: Knee tissue from five cadavers and six total knee replacement patients, and 14 teeth from eight patients were scanned using laboratory CT as training data for the developed super-resolution (SR) technique. The method was benchmarked against ex vivo test set, 52 osteochondral samples are imaged with clinical and laboratory CT. A quality assurance phantom was imaged with clinical CT to quantify the technical image quality. To visually assess the clinical image quality, musculoskeletal and maxillofacial CBCT studies were enhanced with SR and contrasted to interpolated images. A dental radiologist and surgeon reviewed the maxillofacial images. RESULTS: The SR models predicted the bone morphological parameters on the ex vivo test set more accurately than conventional image processing. The phantom analysis confirmed higher spatial resolution on the SR images than interpolation, but image grayscales were modified. Musculoskeletal and maxillofacial CBCT images showed more details on SR than interpolation; however, artifacts were observed near the crown of the teeth. The readers assessed mediocre overall scores for both SR and interpolation. The source code and pretrained networks are publicly available. CONCLUSION: Model training with laboratory modalities could push the resolution limit beyond state-of-the-art clinical musculoskeletal and dental CBCT. A larger maxillofacial training dataset is recommended for dental applications.

Association between vertebral cross-sectional area and lumbar disc displacement - a population-based study.

PURPOSE: Vertebral dimensions may constitute a potential risk factor for degenerative changes in the spine. Previous studies have found a positive association between vertebral height and both type 2 Modic changes and intervertebral disc height loss. Also, vertebral endplate size has been associated with disc degeneration. However, only a few studies have investigated the association between vertebral dimensions and lumbar disc displacement (LDD). This study aimed to investigate the association between vertebral cross-sectional area (CSA) and LDD among the general middle-aged Finnish population. We hypothesized that larger vertebral CSA is associated with LDD. MATERIALS AND METHODS: The study was conducted by using data from the Northern Finland Birth Cohort 1966 (NFBC1966). At the age of 46, a subpopulation of NFBC1966 underwent clinical examinations including magnetic resonance imaging (MRI) (n = 1249). MRI scans were used to measure L4 CSA and evaluate the presence of LDD (bulge, protrusion, and extrusion/sequestration) in the adjacent discs. The association between L4 CSA and LDD was analysed using logistic regression, with adjustment for sex, education, body mass index, leisure-time physical activity, smoking, diet, and L4 height. RESULTS: Larger L4 CSA was associated with LDD; an increase of 1 cm2 in vertebral CSA elevated the odds of LDD relative to no LDD by 10% (adjusted odds ratio 1.10, 95% CI 1.01-1.19). The association was similar among either sex. CONCLUSIONS: Larger L4 vertebral CSA was associated with LDD in our study sample. Even though smaller vertebral size exposes our vertebrae to osteoporotic fractures, it simultaneously seems to protect us from LDD.

Observing the fragmentation of two expanding bullet types and a full metal-jacketed bullet with computed tomography-a forensic ballistics case study.

Computed tomography (CT) may have a crucial role in the forensic documentation and analysis of firearm injuries. The aim of this forensic ballistics case study was to explore whether two types of expanding bullets and a full metal-jacketed bullet could be differentiated by inspecting bullet fragments and fragmentation pattern in CT. Three types of .30 caliber bullets (full metal-jacketed Norma Jaktmatch, expanding full-copper Norma Ecostrike, and expanding soft-point Norma Oryx) were test fired from a distance of 5 m to blocks of 10% ballistic gelatine. CT scans of the blocks were obtained with clinical equipment and metal artifact reduction. Radiopaque fragments were identified and fragmentation parameters were obtained from the scans (total number of fragments, maximum diameter of the largest fragment, distance between entrance and the closest fragment, length of the fragment cloud, and maximum diameters of the fragment cloud). The fragmentation patterns were additionally visualized by means of 3D reconstruction. In CT, the bullet types differed in several fragmentation parameters. While the expanding full-copper bullet Ecostrike left behind only a single fragment near the end of the bullet channel, the soft-point Oryx had hundreds of fragments deposited throughout the channel. For both expanding bullets Ecostrike and Oryx, the fragments were clearly smaller than those left behind by the full metal-jacketed Jaktmatch. This was surprising as the full metal-jacketed bullet was expected to remain intact. The fragment cloud of Jaktmatch had similar mediolateral and superoinferior diameters to that of Oryx; however, fragments were deposited in the second half of the gelatine block, and not throughout the block. This case study provides a basis and potential methodology for further experiments. The findings are expected to benefit forensic practitioners with limited background information on gunshot injury cases, for example, those that involve several potential firearms or atypical gunshot wounds. The findings may prove beneficial for both human and wildlife forensics.

Semiautomatic Assessment of Facet Tropism From Lumbar Spine MRI Using Deep Learning: A Northern Finland Birth Cohort Study.

STUDY DESIGN: This is a retrospective, cross-sectional, population-based study that automatically measured the facet joint (FJ) angles from T2-weighted axial magnetic resonance imagings (MRIs) of the lumbar spine using deep learning (DL). OBJECTIVE: This work aimed to introduce a semiautomatic framework that measures the FJ angles using DL and study facet tropism (FT) in a large Finnish population-based cohort. SUMMARY OF DATA: T2-weighted axial MRIs of the lumbar spine (L3/4 through L5/S1) for (n=1288) in the NFBC1966 Finnish population-based cohort were used for this study. MATERIALS AND METHODS: A DL model was developed and trained on 430 participants' MRI images. The authors computed FJ angles from the model's prediction for each level, that is, L3/4 through L5/S1, for the male and female subgroups. Inter-rater and intrarater reliability was analyzed for 60 participants using annotations made by two radiologists and a musculoskeletal researcher. With the developed method, we examined FT in the entire NFBC1966 cohort, adopting the literature definitions of FT thresholds at 7° and 10°. The rater agreement was evaluated both for the annotations and the FJ angles computed based on the annotations. FJ asymmetry ( - was used to evaluate the agreement and correlation between the raters. Bland-Altman analysis was used to assess the agreement and systemic bias in the FJ asymmetry. The authors used the Dice score as the metric to compare the annotations between the raters. The authors evaluated the model predictions on the independent test set and compared them against the ground truth annotations. RESULTS: This model scored Dice (92.7±0.1) and intersection over union (87.1±0.2) aggregated across all the regions of interest, that is, vertebral body (VB), FJs, and posterior arch (PA). The mean FJ angles measured for the male and female subgroups were in agreement with the literature findings. Intrarater reliability was high, with a Dice score of VB (97.3), FJ (82.5), and PA (90.3). The inter-rater reliability was better between the radiologists with a Dice score of VB (96.4), FJ (75.5), and PA (85.8) than between the radiologists and the musculoskeletal researcher. The prevalence of FT was higher in the male subgroup, with L4/5 found to be the most affected region. CONCLUSION: The authors developed a DL-based framework that enabled us to study FT in a large cohort. Using the proposed method, the authors present the prevalence of FT in a Finnish population-based cohort.

Assessment of articular cartilage of ankle joint in stable and unstable unilateral weber type-B/SER-type ankle fractures shortly after trauma using T2 relaxation time.

Background: Early detection of post-traumatic cartilage damage in the ankle joint in magnetic resonance images can be difficult due to disturbances to structures usually appearing over time. Purpose: To study the articular cartilage of unilateral Weber type-B/SER-type ankle fractures shortly post-trauma using T2 relaxation time. Material and Methods: Fifty one fractured ankles were gathered from consecutively screened patients, compiled initially for RCT studies, and treated at Oulu University Hospital and classified as stable (n = 28) and unstable fractures (n = 23) based on external-rotation stress test: medial clear space of ≥5 mm was interpreted as unstable. A control group of healthy young individuals (n = 19) was also gathered. All ankles were imaged on average 9 (range: 1 to 25) days after injury on a 3.0T MRI unit for T2 relaxation time assessment, and the cartilage was divided into sub-regions for comparison. Results: Control group displayed significantly higher T2 values in tibial cartilage compared to stable (six out of nine regions, p-values = .003-.043) and unstable (six out of nine regions, p-values = .001-.037) ankle fractures. No differences were detected in talar cartilage. Also, no differences were observed between stable and unstable fractures in tibial or talar cartilage. Conclusions: Lower T2 relaxation times of tibial cartilage in fractured ankles suggest intact extra cellular matrix (ECM) of the cartilage. Severity of the ankle fracture, measured by ankle stability, does not seem to increase ECM degradation immediately after trauma.

Early disc degeneration in radiotherapy-treated childhood brain tumor survivors.

BACKGROUND: Childhood brain tumor (BT) survivors have an increased risk of treatment-related late effects, which can reduce health-related quality of life and increase morbidity. This study aimed to investigate lumbar disc degeneration in magnetic resonance imaging (MRI) in adult survivors of radiotherapy-treated childhood BT compared to age and sex-matched population controls. METHODS: In this cross-sectional comparative study, 127 survivors were identified from hospital registries. After a mean follow-up of 20.7 years (range 5-33.1), 67 survivors (mean age 28.4, range 16.2-43.5) were investigated with MRI and compared to 75 sex-matched population-based controls. Evaluated MRI phenotypes included Pfirrmann grading, , intervertebral disc protrusions, extrusions, and high-intensity-zone-lesions (HIZ). Groups were also compared for known risk factors of lumbar intervertebral disc (IVD) degeneration. RESULTS: Childhood BT survivors had higher Pfirrmann grades than controls at all lumbar levels (all p < 0.001). Lumbar disc protrusions at L4-5 (p = 0.02) and extrusions at L3-4 (p = 0.04), L4-5 (p = 0.004), and L5-S1 (p = 0.01) were significantly more common in the BT group compared to the control. The survivor cohort also had significantly more HIZ-lesons than the controls (n=13 and n=1, p=0.003). Age at diagnosis was associated with lower degree of IVD degeneration (p < 0.01). Blood pressure correlated with IVD degeneration (P < 0.05). CONCLUSIONS: Signs of early disc degeneration related to tumor treatment can be seen in the IVDs of survivors. Disc degeneration was more severe in children treated in adolescence.

The role of co-occurring insomnia and mental distress in the association between lumbar disc degeneration and low back pain related disability.

BACKGROUND: Lumbar disc degeneration (LDD) is associated with low back pain (LBP). Although both insomnia and mental distress appear to influence the pain experience, their role in the association between LDD and LBP is uncertain. Our objective was to investigate the role of co-occurring insomnia and mental distress in the association between LDD and LBP-related disability. METHODS: A total of 1080 individuals who had experienced LBP during the previous year underwent 1.5-T lumbar magnetic resonance imaging, responded to questionnaires, and participated in a clinical examination at the age of 47. Full data was available for 843 individuals. The presence of LBP and LBP-related disability (numerical rating scale, range 0-10) were assessed using a questionnaire. LDD was assessed by a Pfirrmann-based sum score (range 0-15, higher values indicating higher LDD). The role of insomnia (according to the five-item Athens Insomnia Scale) and mental distress (according to the Hopkins Symptom Check List-25) in the association between the LDD sum score and LBP-related disability was analyzed using linear regression with adjustments for sex, smoking, body mass index, education, leisure-time physical activity, occupational physical exposure, Modic changes, and disc herniations. RESULTS: A positive association between LDD and LBP-related disability was observed among those with absence of both mental distress and insomnia (adjusted B = 0.132, 95% CI = 0.028-0.236, p = 0.013), and among those with either isolated mental distress (B = 0.345 CI = 0.039-0.650, p = 0.028) or isolated insomnia (B = 0.207, CI = 0.040-0.373, p = 0.015). However, among individuals with co-occurring insomnia and mental distress, the association was not significant (B = -0.093, CI = -0.346-0.161, p = 0.470). CONCLUSIONS: LDD does not associate with LBP-related disability when insomnia and mental distress co-occur. This finding may be useful when planning treatment and rehabilitation that aim to reduce disability among individuals with LDD and LBP. Future prospective research is warranted.

Clinical Follow-Up without Radiographs Is Sufficient after Most Nonoperatively Treated Distal Radius Fractures in Children.

Distal forearm fractures are common in children and are usually treated nonoperatively. No consensus has been reached on how to perform clinical and radiographic follow-up of these fractures. Our aim was to study whether radiographic and clinical follow-up is justified. We included 100 consecutive patients with non-operatively treated distal forearm fractures who were treated at Oulu University Hospital in 2010-2011. The natural history of the fractures during the nonoperative treatment was analyzed by measuring the potential worsening of the alignment during the follow-up period. The limits of acceptable fracture position were set according to the current literature using "strict" or "wide" criteria for alignment. We determined the rate of worsening fracture position (i.e., patients who reached the threshold of unacceptable alignment). In relation to splinting, we evaluated how many patients benefited from clinical follow-up. Most of the fractures (98%) preserved acceptable alignment during the entire follow-up period when wide criteria were used. The application of stricter criteria for alignment in radiographs showed loss of reduction in 19% of the fractures. Worsening of the alignment was recognized at a mean of 13 days (range 5-29) after the injury. One in three (32%) patients needed some intervention due to splint loosening or failure. Radiographic follow-up of nonoperatively treated distal forearm fractures remains questionable. Instead, clinical follow-up is important, as 32% of patients needed their splints fixed.

External Validation of SpineNet, an Open-Source Deep Learning Model for Grading Lumbar Disk Degeneration MRI Features, Using the Northern Finland Birth Cohort 1966.

STUDY DESIGN: This is a retrospective observational study to externally validate a deep learning image classification model. OBJECTIVE: Deep learning models such as SpineNet offer the possibility of automating the process of disk degeneration (DD) classification from magnetic resonance imaging (MRI). External validation is an essential step to their development. The aim of this study was to externally validate SpineNet predictions for DD using Pfirrmann classification and Modic changes (MCs) on data from the Northern Finland Birth Cohort 1966 (NFBC1966). SUMMARY OF DATA: We validated SpineNet using data from 1331 NFBC1966 participants for whom both lumbar spine MRI data and consensus DD gradings were available. MATERIALS AND METHODS: SpineNet returned Pfirrmann grade and MC presence from T2-weighted sagittal lumbar MRI sequences from NFBC1966, a data set geographically and temporally separated from its training data set. A range of agreement and reliability metrics were used to compare predictions with expert radiologists. Subsets of data that match SpineNet training data more closely were also tested. RESULTS: Balanced accuracy for DD was 78% (77%-79%) and for MC 86% (85%-86%). Interrater reliability for Pfirrmann grading was Lin concordance correlation coefficient=0.86 (0.85-0.87) and Cohen κ=0.68 (0.67-0.69). In a low back pain subset, these reliability metrics remained largely unchanged. In total, 20.83% of disks were rated differently by SpineNet compared with the human raters, but only 0.85% of disks had a grade difference >1. Interrater reliability for MC detection was κ=0.74 (0.72-0.75). In the low back pain subset, this metric was almost unchanged at κ=0.76 (0.73-0.79). CONCLUSIONS: In this study, SpineNet has been benchmarked against expert human raters in the research setting. It has matched human reliability and demonstrates robust performance despite the multiple challenges facing model generalizability.

Modic changes associated with greater pain relief following anesthetization of the adjacent lumbar intervertebral disc: A retrospective study of chronic low back pain patients.

PURPOSE: To assess the correlation between the degree of pain relief following discoblock and the presence and type of adjacent Modic changes (MC). METHOD: We retrospectively analyzed chronic low back pain (LBP) patients whose pain was suspected to originate from a specific lumbar intervertebral disc (IVD) based on a spine orthopedist's clinical evaluation and magnetic resonance imaging (MRI). Thus, patients were selected to undergo discoblock. We calculated the degree of pain relief following discoblock on Numerical Rating Scale (ΔNRS) and analyzed the MRIs on the basis of MC presence and type on the lumbar spinal segment in question. We assessed the differences in ΔNRS between the groups with absent and present MC and the groups of MC subtypes. RESULTS: Forty-five patients were included in the present study, all of whom underwent discoblock at a single level. The total MC prevalence was 77.8 % (35 patients); pure or dominant MC type 1 (MC1 group) 35.6 % (16 patients); and pure or dominant MC type 2 (MC2 group) 42.2 % (19 patients). ΔNRS was significantly greater in the group with MC compared to the group without MC (median ΔNRS -5.0 vs -2.5, respectively, P = 0.043). In pairwise comparisons, a significant difference in ΔNRS was found between the MC1 group and the group without MC (median ΔNRS -5.0 vs -2.5, respectively, P = 0.012). CONCLUSIONS: We propose that MC type 1 are associated with lumbar spinal pain, and that the pain arises at least partly from the adjacent IVD or endplate.

Retrograde intramedullary nailing of the radius in children: A pilot magnetic resonance imaging study of soft-tissue findings.

Purpose: Unstable forearm shaft fractures in children are preferably treated surgically using elastic stable intramedullary nails. The radius is nailed retrograde from the distal metaphysis. There is a risk of surgery-related soft-tissue complications during the operation. Close evaluation of occult surgery-related soft-tissue lesions has not been possible previously, due to the titanium alloy hardware used in the process. The aim of the present study was to evaluate the potential findings in the surrounding soft tissues after intramedullary nailing of the radius, by using magnetic resonance imaging. Methods: The study population comprised 15 pediatric patients with forearm shaft fractures treated by polylactide-co-glycolide biodegradable intramedullary nails and postoperatively evaluated via magnetic resonance imaging. The main outcome was signal abnormality in any tendon at the entry point postoperatively. Secondarily, other changes in the soft tissues related to nailing were determined. Furthermore, the precise location of the entry point and the anatomic characteristics of the soft-tissue tunnel were described. Results: In total, 5 of 15 patients (33.3%) had transient signal pathology in a tendon postoperatively. Edema around the superficial radial nerve was detected in 13 of 15 patients (86.7%). The most common surgical approach was between the extensor pollicis brevis and the extensor carpi radialis longus tendons, which was applied in 10 of 15 patients (66.7%). Conclusions: One in three patients exhibited transient and occult surgery-related intraparenchymal signal pathology in a tendon, after forearm intramedullary nailing. Caution with surgical prepare of the soft-tissue cleavage is recommended. Level of evidence: IV.

Gravidity, parity and knee breadth at midlife: a population-based cohort study.

Gestation increases the biomechanical loading of lower extremities. Gestational loading may influence anthropometrics of articular surfaces in similar means as bone diaphyseal properties. This study aimed to investigate whether gravidity (i.e. number of pregnancies) and parity (i.e. number of deliveries) is associated with knee breadth among middle-aged women. The study sample comprised 815 women from the Northern Finland Birth Cohort 1966. The median parity count of our sample was 2 and the median gravidity count 3. At the age of 46, questionnaires were used to enquire gravidity and parity, and posteroanterior knee radiographs were used to obtain two knee breadth parameters (tibial plateau mediolateral breadth (TPML) and femoral condylar mediolateral breadth (FCML)) as representatives of articular size. The associations of gravidity and parity with knee breadth were analyzed using general linear models with adjustments for height, weight, leisure-time physical activity, smoking, and education years. Individuals with osteoarthritic changes were excluded from our sample. The mean TPML in our sample was 70.3 mm and the mean FCML 71.6 mm respectively. In the fully adjusted models, gravidity and parity showed positive associations with knee breadth. Each pregnancy was associated with 0.11-0.14% larger knee breath (p < 0.05), and each delivery accounted for an increase of 0.20% in knee breadth (p < 0.01). Between-group comparisons showed that multiparous women had 0.68-1.01% larger knee breath than nulli- and primiparous women (p < 0.05). Pregnancies and deliveries seem to increase the mediolateral breadth of the knee. This increase is potentially associated with increased biomechanical loadings during gestation.

Accelerometer-measured physical activity is associated with knee breadth in middle-aged Finns - a population-based study.

BACKGROUND: Articular surface size is traditionally considered to be a relatively stable trait throughout adulthood. Increased joint size reduces bone and cartilage tissue strains. Although physical activity (PA) has a clear association with diaphyseal morphology, the association between PA and articular surface size is yet to be confirmed. This cross-sectional study aimed to clarify the role of moderate-to-vigorous PA (MVPA) in knee morphology in terms of tibiofemoral joint size. METHODS: A sample of 1508 individuals from the population-based Northern Finland Birth Cohort 1966 was used. At the age of 46, wrist-worn accelerometers were used to monitor MVPA (≥3.5 METs) during a period of two weeks, and knee radiographs were used to obtain three knee breadth measurements (femoral biepicondylar breadth, mediolateral breadth of femoral condyles, mediolateral breadth of the tibial plateau). The association between MVPA and knee breadth was analyzed using general linear models with adjustments for body mass index, smoking, education years, and accelerometer weartime. RESULTS: Of the sample, 54.8% were women. Most individuals were non-smokers (54.6%) and had 9-12 years of education (69.6%). Mean body mass index was 26.2 (standard deviation 4.3) kg/m2. MVPA was uniformly associated with all three knee breadth measurements among both women and men. For each 60 minutes/day of MVPA, the knee breadth dimensions were 1.8-2.0% (or 1.26-1.42 mm) larger among women (p < 0.001) and 1.4-1.6% (or 1.21-1.28 mm) larger among men (p < 0.001). CONCLUSIONS: Higher MVPA is associated with larger tibiofemoral joint size. Our findings indicate that MVPA could potentially increase knee dimensions through similar biomechanical mechanisms it affects diaphyseal morphology, thus offering a potential target in reducing tissue strains and preventing knee problems. Further studies are needed to confirm and investigate the association between articulation area and musculoskeletal health.

Detecting Patient Safety Errors by Characterizing Incidents Reported by Medical Imaging Staff.

The objectives of the study were to characterize events related to patient safety reported by medical imaging personnel in Finland in 2007-2017, the number and quality of reported injuries, the risk assessment, and the planned improvement of operations. The information was collected from a healthcare patient safety incident register system. The data contained information on the nature of the patient safety errors, harms and near-misses in medical imaging, the factors that lead to the events, the consequences for the patient, the level of risks, and future measures. The number of patient safety incident reports included in the study was 7,287. Of the incident reports, 75% concerned injuries to patients and 25% were near-misses. The most common consequence of adverse events and near-misses were minor harm (37.2%) related to contrast agent, or no harm (27.9%) related to equipment malfunction. Supervisors estimated the risks as low (47.7%) e.g., data management, insignificant (35%) e.g., verbal communication or moderate (15.7%) e.g., the use of contrast agent. The most common suggestion for learning from the incident was discussing it with the staff (58.1%), improving operations (5.7%) and submitting it to a higher authority (5.4%). Improving patient safety requires timely, accurate and clear reporting of various patient safety incidents. Based on incident reports, supervisors can provide feedback to staff, develop plans to prevent accidents, and monitor the impact of measures taken. Information on the development of occupational safety should be disseminated to all healthcare professionals so that the same mistakes are not repeated.

Association of lumbar disc degeneration with low back pain in middle age in the Northern Finland Birth Cohort 1966.

BACKGROUND: Although it has been suggested that lumbar disc degeneration (LDD) is a significant risk factor for low back pain (LBP), its role remains uncertain. Our objective was to clarify the association between LDD and LBP and whether mental distress modifies the association. METHODS: Participants of a birth cohort underwent 1.5-T lumbar magnetic resonance imaging at the age of 47. The association between the sum score of LDD (Pfirrmann classification, range 0-15) and LBP (categorized into "no pain", "mild-to-moderate pain", "bothersome-and-frequent pain") was assessed using logistic regression analysis, with sex, smoking, body mass index, physical activity, occupational exposure, education, and presence of Modic changes and disc herniations as confounders. The modifying role of mental distress (according to the Hopkins Symptom Check List-25 [HSCL-25], the Beck Depression Inventory and the Generalized Anxiety Disorder Scale) in the association was analyzed using linear regression. RESULTS: Of the study population (n = 1505), 15.2% had bothersome and frequent LBP, and 29.0% had no LBP. A higher LDD sum score increased the odds of belonging to the "mild-to-moderate pain" category (adjusted OR corresponding to an increase of one point in the LDD sum score 1.11, 95% CI 1.04-1.18, P = 0.003) and the "bothersome-and-frequent pain" category (adjusted OR 1.20, 95% CI 1.10-1.31, P < 0.001), relative to the "no pain" category. Mental distress significantly modified the association between LDD and LBP, as a linear positive association was consistently observed among individuals without mental distress according to HSCL-25 (adjusted B 0.16, 95% CI 0.07-0.26, P < 0.001), but not among individuals with higher mental distress. CONCLUSIONS: LDD was significantly associated with both mild-to-moderate and bothersome-and-frequent LBP. However, the co-occurrence of mental distress diminished the association between LDD and LBP bothersomeness. Our results strongly suggest that mental symptoms affect the pain experience.