[How I treat... a fracture of the coronoid apophysis, choice between conservative attitude and surgical treatment]. / Comment je traite...une fracture de l'apophyse coronoïde, entre attitude conservatrice et traitement chirurgical.

Fractures of the coronoid process are the rarest mandibular fractures and are mostly associated with other maxillofacial fractures. They are most often encountered in trauma. The CT-scanner is the gold standard for locating and characterizing this lesion. Although the diagnosis is made radiologically, clinical examination may reveal various symptoms specific to this fracture, which may appear frustrated when other facial fractures are associated. In most cases, conservative treatment by intermaxillary fixation is preferred. However, in specific cases, surgical intervention such as coronoidectomy or open reduction with osteosynthesis is indicated. The type of fracture, its location, the delay before its management, the clinic and the presence of associated fractures guide the therapeutic attitude. Surgical management must be followed by early and intensive physiotherapy to avoid zygomatico-coronoid ankylosis, the main complication of this fracture.

Les fractures de l'apophyse coronoïde sont les fractures mandibulaires les plus rares et majoritairement associées à d'autres fractures maxillo-faciales. Elles se rencontrent le plus souvent lors de traumatisme. Le CT-scanner est le gold standard pour localiser et caractériser cette lésion. Bien que le diagnostic soit radiologique, l'examen clinique peut révéler différents symptômes propres à cette fracture et qui peuvent paraître frustres lorsque d'autres fractures du massif facial y sont associées. Dans la majorité des cas, le traitement conservateur par fixation intermaxillaire est privilégié. Mais dans des indications précises, une intervention chirurgicale, comme une coronoïdectomie ou une réduction ouverte avec ostéosynthèse, est indiquée. Le type de fracture, sa localisation, le délai avant sa prise en charge, la clinique et la présence de fractures associées guident l'attitude thérapeutique. Une prise en charge chirurgicale doit être suivie de physiothérapie précoce et intensive pour éviter l'ankylose zygomatico-coronoïde, principale complication de cette fracture.

The role of stem cell-derived exosomes in the repair of cutaneous and bone tissue.

Exosomes are extracellular vesicles secreted by various cell types, which play important roles in physiological processes. In particular, stem cell-derived exosomes have been shown to play crucial functions in intercellular communication during the tissue healing process. This review summarizes the effects of exosomes derived from different stem cell sources on the repair of cutaneous and bone tissue, focusing on the different pathways that could be involved in the regeneration process. The biogenesis, isolation, and content of exosomes have also been discussed. The effectiveness of exosomes is broadly demonstrated for skin and bone regeneration in animal models, supporting the basis for clinical translation of exosomes as a ready-to-use cell-free therapeutic for skin and bone regeneration.

"Do-not-touch" lesions of bone revisited.

Incidental bone lesions are encountered frequently in day-to-day practice. Many of these lesions are indeterminate requiring referral to specialist centres for further characterisation with or without biopsy; however, as biopsy has its own drawbacks, not all lesions can be subjected to biopsy. The primary role of a radiologist in these situations is to characterise these lesions based on their imaging appearances into aggressive lesions requiring biopsy and non-aggressive lesions that do not require a biopsy. The term "do-not-touch lesion" is used to describe a lesion with typical radiographic appearances that can be characterised based on radiographic appearances alone without needing a biopsy. With recent advances in imaging, many incidental lesions can be characterised into do-not-touch lesions based on their imaging appearances alone using a single imaging technique or using a combination of imaging techniques and, less frequently, with the additional help of serological investigations, without the need for biopsy. Hence, the definition of do-not-touch lesions of bone needs a revisit. In this article, we attempt to redefine do-not-touch lesions of bone and propose an imaging-based classification for characterisation of these lesions.

Evaluation of the effects of preconditioned human stem cells plus a scaffold and photobiomodulation administration on stereological parameters and gene expression levels in a critical size bone defect in rats.

We assessed the impact of photobiomodulation (PBM) plus adipose-derived stem cells (ASCs) during the anabolic and catabolic stages of bone healing in a rat model of a critical size femoral defect (CSFD) that was filled with a decellularized bone matrix (DBM). Stereological analysis and gene expression levels of bone morphogenetic protein 4 (BMP4), Runt-related transcription factor 2 (RUNX2), and stromal cell-derived factor 1 (SDF1) were determined. There were six groups of rats. Group 1 was the untreated control or DBM. Study groups 2-6 were treated as follows: ASC (ASC transplanted into DBM, then implanted in the CSFD); PBM (CSFD treated with PBM); irradiated ASC (iASC) (ASCs preconditioned with PBM, then transplanted into DBM, and implanted in the CSFD); ASC + PBM (ASCs transplanted into DBM, then implanted in the CSFD, followed by PBM administration); and iASC + PBM (the same as iASC, except CSFDs were exposed to PBM). At the anabolic step, all treatment groups had significantly increased trabecular bone volume (TBV) (24.22%) and osteoblasts (83.2%) compared to the control group (all, p = .000). However, TBV in group iASC + PBM groups were superior to the other groups (97.48% for osteoblast and 58.8% for trabecular bone volume) (all, p = .000). The numbers of osteocytes in ASC (78.2%) and iASC + PBM (30%) groups were remarkably higher compared to group control (both, p = .000). There were significantly higher SDF (1.5-fold), RUNX2 (1.3-fold), and BMP4 (1.9-fold) mRNA levels in the iASC + PBM group compared to the control and some of the treatment groups. At the catabolic step of bone healing, TBV increased significantly in PBM (30.77%), ASC + PBM (32.27%), and iASC + PBM (35.93%) groups compared to the control group (all, p = .000). There were significantly more osteoblasts and osteocytes in ASC (71.7%, 62.02%) (p = .002, p = .000); PBM (82.54%, 156%), iASC (179%, 23%), and ASC + PBM (108%, 110%) (all, p = .000), and iASC + PBM (79%, 100.6%) (p = .001, p = .000) groups compared to control group. ASC preconditioned with PBM in vitro plus PBM in vivo significantly increased stereological parameters and SDF1, RUNX2, and BMP4 mRNA expressions during bone healing in a CSFD model in rats.

3D-Printing Biodegradable PU/PAAM/Gel Hydrogel Scaffold with High Flexibility and Self-Adaptibility to Irregular Defects for Nonload-Bearing Bone Regeneration.

A three-dimensional (3D) printed biodegradable hydrogel scaffold with a strong self-expanding ability to conform to the contour of irregular bone defects and be closely adjacent to host tissues is reported herein. The scaffold has a triple cross-linked network structure consisting of photo-cross-linked polyacrylamide (PAAM) and polyurethane (PU) as the primary IPN network and chemical cross-linked gelatin (Gel) as the secondary network, which confers the scaffold with good mechanical properties. The addition of PU in the polymerization process of acrylamide (AAM) can improve the ultraviolet (UV) photocuring efficiency of the hydrogel and incorporate abundant hydrogen bonds between the PAAM copolymer chain and the PU chain. The results show that the hydrogel scaffold contains regular structures with smooth morphology, excellent dimensional stability, and uniform aperture. The degradation rate of the hydrogel scaffold is controllable through adjusting cross-linking agents and can be up to about 60% after degradation for 28 days. More importantly, the rapid self-inflating characteristic of the scaffold in water, that is, the volume of hydrogel scaffold can increase to about 8 times that of their own in an hour and can generate a slight compressive stress on the surrounding host tissue, thus stimulating the reconstruction and growth of new bone tissues. The in vitro experiment indicates that the scaffold is nontoxic and biocompatible. The in vivo experiment shows that the PU/PAAM/Gel chemically cross-linked scaffold displays the desirable osteogenic capability. This UV-curable 3D printed self-adaptive and degradable hydrogel scaffold holds great potential for nonload-bearing bone repair.

Through fire and flames: post-burning survival and detection of dismemberment-related toolmarks in cremated cadavers.

During a homicide investigation in which fire has been used to reduce the size of the cadaver and conceal the evidence of injuries, the identification of perimortem trauma presents a challenge, in particular in cases when the perpetrator has dismembered the body followed by burning the remains. It is therefore important to understand the effects which heat causes on fresh bone. The aim of this paper is to perform a pilot study on the survival ratio of toolmarks in different anatomical regions associated with dismemberment, and a descriptive analysis of the variables that may potentially influence the post-burning survival and detection. To achieve this, three donated embalmed cadavers were used to simulate a case in which an attempted dismemberment and burning had occurred. Fifty-five pre-burning injuries were manually induced: 30 using a machete to inflict chopping trauma, and 25 with a serrated bread knife to inflict sharp force trauma, on the thigh, knee, ankle and wrist. The cadavers were cremated in a furnace at Madrid's Cementerio Sur and the burnt remains were analysed at the Laboratorio de Antropología y Odontología Forense of the Universidad Complutense de Madrid. Not all pre-burning injuries inflicted were visible after the cremation process; only 13% were detected in this experiment. Toolmarks can be masked, modified, destroyed or overlooked from the outset of the procedure due to several factors which influence the post-burning survival and detection of toolmarks and contribute to conceal the evidence of trauma. Additional research should be done to study further variables which affect the post-burning visibility of sharp force trauma.

Scavenger activity in a peri-urban agricultural setting in the Highveld of South Africa.

Scavenging animals often scatter skeletal remains of forensic interest and cause scavenging damage. This study aimed to identify scavenging animals in the peri-urban agricultural Highveld of South Africa, describe their scattering patterns, and the damage they cause to bone. Ten pig carcasses (Sus scrofa domesticus) (40-80 kg) were placed at the University of Pretoria's Mierjie Le Roux Experimental Farm (Highveld) in summer and winter. Motion-activated cameras recorded the scavenging. Scavenger species were identified and their behaviors, scattering pattern, and the damage they cause to bone were described. Scavenging was primarily by black-backed jackals; however, mongooses (slender, yellow, and water mongoose), Cape porcupine, and honey badger were also active. Remains were commonly scattered in two directions by jackals. The distance of scattering was heavily influenced by fencing. The remains were scattered within a maximum radius of 73.7 m. The remains were scavenged and skeletonized faster in summer. Jackals caused minimal damage to bone, isolated to superficial, nonspecific scores, furrows, and punctures. A few mongoose bone alterations were present as jagged gnaw marks on the angle of the mandible and gnawing of the vertebral spinous process. Cape porcupine bone damage included gnaw marks on the condyle of a femur and head of humerus, and destruction of the proximal and distal ends of a tibia. The described scattering pattern and bone modification patterns will assist in the recovery and analysis of scavenged remains found in peri-urban agricultural areas in South Africa.

Troubles in Tuva: Patterns of perimortem trauma in a nomadic community from Southern Siberia (second to fourth c. CE).

OBJECTIVES: Warfare is assumed to be one of the defining cultural characteristics of steppe nomads in Eastern Eurasia. For the first-centuries CE, a period of political turmoil in Northern China and Southern Siberia, relatively few data are, however, available about the degree and variability of violence in these communities. Here, we provide new data on violence among steppe nomads during the first-centuries CE by analyzing the type, anatomical distribution, and demographic distribution of perimortem trauma at Tunnug1 (Tuva, Southern Siberia-second to fourth c. CE). MATERIALS AND METHODS: Perimortem traumas were assessed on 87 individuals representing both sexes and different age classes. The timing of the lesions was assessed based on morphological criteria, including the absence and presence of bone reactive processes and the relative plasticity of the bone at the moment of impact. The distribution by age, sex, and anatomical location of trauma was analyzed by means of logistic models, Fisher's exact tests, and 3D visualizations. RESULTS: A total of 130 perimortem traumas, including chop marks, slice marks, penetrating lesions, and blunt traumas were identified on 22 individuals. Chop marks were mostly at the level of the skull and vertebrae and were likely caused by bladed weapons. Slice marks were found on the cervical vertebrae and cranium and may be the result of throat slitting and scalping by means of smaller bladed implements. Traumas were more frequent in males, and their presence is not correlated with age. DISCUSSION: This study adds new data to the few available regarding violence among steppe nomadic cultures and provides new insights about the effects of political instability on the life of the people inhabiting Eastern Eurasia during the early centuries CE.

The Progress of Stem Cell Technology for Skeletal Regeneration.

Skeletal disorders, such as osteoarthritis and bone fractures, are among the major conditions that can compromise the quality of daily life of elderly individuals. To treat them, regenerative therapies using skeletal cells have been an attractive choice for patients with unmet clinical needs. Currently, there are two major strategies to prepare the cell sources. The first is to use induced pluripotent stem cells (iPSCs) or embryonic stem cells (ESCs), which can recapitulate the skeletal developmental process and differentiate into various skeletal cells. Skeletal tissues are derived from three distinct origins: the neural crest, paraxial mesoderm, and lateral plate mesoderm. Thus, various protocols have been proposed to recapitulate the sequential process of skeletal development. The second strategy is to extract stem cells from skeletal tissues. In addition to mesenchymal stem/stromal cells (MSCs), multiple cell types have been identified as alternative cell sources. These cells have distinct multipotent properties allowing them to differentiate into skeletal cells and various potential applications for skeletal regeneration. In this review, we summarize state-of-the-art research in stem cell differentiation based on the understanding of embryogenic skeletal development and stem cells existing in skeletal tissues. We then discuss the potential applications of these cell types for regenerative medicine.

Musculoskeletal Injury History Is Associated With Lower Physical and Mental Health in a Historical Cohort of Former National Football League Players.

CONTEXT: Little research has examined health-related quality of life in former National Football League (NFL) players. OBJECTIVE: Examine the association of musculoskeletal injury history and current self-reported physical and mental health in former NFL players. SETTING: Cross-sectional questionnaire. PATIENTS OR OTHER PARTICIPANTS: Historical cohort of 2,103 former NFL players that played at least one season between 1940 and 2001. INTERVENTION: Players were grouped by self-reported professional career musculoskeletal injury history and whether injuries affected current health: (1) no musculoskeletal injury history; (2) musculoskeletal injury history, currently affected by injuries; and (3) musculoskeletal injury history, not currently affected by injuries. MAIN OUTCOME MEASURE: The Short Form 36 Measurement Model for Functional Assessment of Health and Well-Being (SF-36) yielded physical and mental health composite scores (PCS and MCS, respectively); higher scores indicated better health. Multivariable linear regression computed mean differences (MD) among injury groups. Covariates included demographics, playing history characteristics, surgical intervention for musculoskeletal injuries, and whether injury resulted in premature end to career. MD with 95% CI excluding 0.00 were deemed significant. RESULTS: Overall, 90.3% reported at least one musculoskeletal injury during their professional football careers, of which 74.8% reported being affected by their injuries at time of survey completion. Adjusting for covariates, mean PCS in the "injury and affected" group was lower than the "no injury" (MD = -3.2; 95% CI: -4.8, -1.7) and "injury and not affected" groups (MD = -4.3; 95% CI: -5.4, -3.3); mean MCS did not differ. CONCLUSION: Many players reported musculoskeletal injuries, highlighting the need for developing and evaluating injury management interventions.

Decellularized bone extracellular matrix in skeletal tissue engineering.

Bone possesses an intrinsic regenerative capacity, which can be compromised by aging, disease, trauma, and iatrogenesis (e.g. tumor resection, pharmacological). At present, autografts and allografts are the principal biological treatments available to replace large bone segments, but both entail several limitations that reduce wider use and consistent success. The use of decellularized extracellular matrices (ECM), often derived from xenogeneic sources, has been shown to favorably influence the immune response to injury and promote site-appropriate tissue regeneration. Decellularized bone ECM (dbECM), utilized in several forms - whole organ, particles, hydrogels - has shown promise in both in vitro and in vivo animal studies to promote osteogenic differentiation of stem/progenitor cells and enhance bone regeneration. However, dbECM has yet to be investigated in clinical studies, which are needed to determine the relative efficacy of this emerging biomaterial as compared with established treatments. This mini-review highlights the recent exploration of dbECM as a biomaterial for skeletal tissue engineering and considers modifications on its future use to more consistently promote bone regeneration.

Bone marrow cell response after injury and during early stage of regeneration is independent of the tissue-of-injury in 2 injury models.

Selectively recruiting bone marrow (BM)-derived stem and progenitor cells to injury sites is a promising therapeutic approach. The coordinated action of soluble factors is thought to trigger the mobilization of stem cells from the BM and recruit them to lesions to contribute to tissue regeneration. Nevertheless, the temporal response profile of the major cellular players and soluble factors involved in priming the BM and recruiting BM-derived cells to promote regeneration is unknown. We show that injury alters the BM cellular composition, introducing population-specific fluctuations during tissue regeneration. We demonstrate that injury causes an immediate, transient response of mesenchymal stromal cells and endothelial cells followed by a nonoverlapping increase in hematopoietic stem and progenitor cells. Moreover, BM reaction is identical whether the injury is inflicted on skin and muscle or also involves a bone defect, but these 2 injury paradigms trigger distinct systemic cytokine responses. Together, our results indicate that the BM response to injury in the early stages of regeneration is independent of the tissue-of-injury based on the 2 models used, but the injured tissue dictates the systemic cytokine response.-Leitão, L., Alves, C. J., Alencastre, I. S., Sousa, D. M., Neto, E., Conceição, F., Leitão, C., Aguiar, P., Almeida-Porada, G., Lamghari, M. Bone marrow cell response after injury and during early stage of regeneration is independent of the tissue-of-injury in 2 injury models.

Analysis of false start bone lesions produced by an electrical oscillating autopsy saw.

Postmortem dismemberment results from the use of sharp or sharp blunt instruments. Saws produce specific bone lesions, and the observation of certain saw mark features allows for the recognition of certain characteristics of the saw and its teeth. At autopsy, sections of the skull and other parts of the skeleton are usually achieved using an electrical oscillating autopsy saw. In cases of dismemberment, this autopsy saw may create additional marks to those produced by the criminal activity. In order to help the forensic pathologist to differentiate the two types of marks, this experimental study used a stereomicroscope to examine 130 experimental false starts produced on animal and human bones by an oscillating autopsy saw. A flagrant succession of narrow and wide aspects of the walls (in a "figure of 8" shape), with obvious oval bone islands and undulating striae are patterns typically left behind by oscillating autopsy saws, but the depth of the false starts plays an important role in the variation of the features. In particular, superficial false starts tend to be associated with larger kerf widths, straight walls, and longitudinal bone islands.

The ballistic performance of bone when impacted by fragments.

Physical models are required to generate the underlying algorithms that populate computer simulations of the effects of explosive fragmenting devices. These models and simulations are used for understanding weapon performance, designing buildings and optimising personal protective equipment. Previous experimental work has investigated the performance of skin and muscle when subjected to fragmentation threats, but limited evidence exists for the performance of bone when impacted by fragments. In the current work, ballistic testing was conducted using two types of internationally recognised steel fragment simulating projectiles (FSPs): (i) 5.5 mm diameter (0.68 g) ball bearing (BBs) and (ii) 1.10 g chisel nosed (CN). These projectiles were fired at isolated swine ribs at impact velocities between 99 and 1265 m/s. Impact events were recorded using a high-speed camera. Selected specimens were analysed post-impact with plain x-radiographs and micro-CT scanning to determine damage to the bone architecture. Bones were perforated with a kinetic energy density (KED) as low as 0.14 J/mm2. Energy transfer to the bone was greater for the CN FSPs, resulting in increased bone damage and the production of secondary bone fragments. The manner in which the bones failed with faster velocity impacts (> 551 m/s; KED > 6.44 J/mm2) was analogous to the behaviour of a brittle material. Slower velocity impacts (< 323 m/s; KED < 1.49 J/mm2) showed a transition in failure mode with the bone displaying the properties of an elastic, plastic and brittle material at various points during the impact. The study gives critical insight into how bone behaves under these circumstances.

Analysis of false starts lesions on human bones produced by two hand saws with high TPI.

Cases of criminal dismemberment are encountered in forensic pathology and forensic anthropology. Saw mark analysis aims to determine the type of saw that was used: hand saw versus electrical saw, crosscut and universal saw versus rip saw, size of the teeth ("teeth per inch" TPI), and set type. The goal of this study was to analyze using a stereomicroscope a series of 60 experimental false starts (30 lesions for each saw) produced on human bones by two different handsaws with a high TPI (15 and 32). The lesions caused by these high TPI saws have rarely been described in the forensic literature. Saw 2 (rip hacksaw with a 32 TPI and a wavy set) displayed classical features. In contrast, saw 1 (universal panel saw, TPI 15, alternating set) did not produce the expected characteristics: the minimum width of the kerf was weak, the kerf walls were straight, the striae were straight, and the kerf profile was very peculiar with a succession of peaks and dips that has not yet been described.

Taphonomic bone trauma caused by Southern African scavengers.

Forensic anthropologists in Southern Africa are often confronted with post-mortem modifications of human skeletal remains caused by animal scavenging. This is troublesome as the post-mortem pseudo-trauma could be misinterpreted. This study aimed to describe the skeletal trauma caused by Southern African scavengers which are of forensic interest. The scavenging animals selected for this study included wild dog, spotted hyena, lion, leopard, black-backed jackal, caracal, and porcupine housed at the National Zoological Gardens of South Africa. Sparsely fleshed and articulated bovine front and hind limbs as well as ribs were placed in each animal enclosure and collected after 2 days for cleaning and analysis. Felids (lion, leopard, and caracal) gnawed away the greater trochanter of the humerus leaving deep, parallel furrows. Hyena caused massive trauma to bone with one-third of the tibia shaft surviving with jagged fracture edges. Porcupines left distinctive fan-like parallel scores and large, oval depressions with an eroded, polished appearance. Wild dogs and jackals did not leave any distinctive patterns. Light scavenging trauma is distinct from other bone taphonomy but cannot be used to determine the species. Heavy scavenging trauma patterns can be used to determine the general type of perpetrating animal; however, the exact taxa or species cannot be determined.

Intra-class and inter-class tool discrimination through micro-CT analysis of false starts on bone.

Micro-CT has successfully been applied to the characterization of false starts (FSs) and, among several parameters, kerf width seems to correlate to the tool blade. The aim of the present study was to evaluate the diagnostic value of micro-CT for the differentiation of saw marks produced by different classes of saws and by saws belonging to the same class and differing only in number of teeth per inches (TPI). A morphological and morphometric analysis of 84 marks, produced by 6 saws belonging to 3 morphological classes, was performed. In the experimental cohort, for each parameter, statistically significant differences in intra- and inter-class analysis were searched for and cut-offs were established. The diagnostic accuracy of cut-offs was assessed through statistical analyses on the validation cohort. The morphological assessment did not allow to differentiate saws differing only in TPI. Angle 1 and top kerf width, respectively for cross-cut and rip-cut saws with alternating set, allowed a good discrimination between FSs produced by tools belonging to the same morphological class. High positive predictive values were found in intra-class analyses, while results in inter-class analyses were less encouraging. In cases of dismemberment, a micro-CT-based analysis of FSs is strongly suggested as a part of a multistep and multimodal methodology of assessment, which includes scanning electron microscopy and stereomicroscopy. A morphological assessment should be followed by an experimental trial and by a morphometric analysis. Further studies are needed to evaluate hampering factors, such as damage by physico-chemical agents.

Clinical use of mass spectrometry (imaging) for hard tissue analysis in abnormal fracture healing.

Common traumas to the skeletal system are bone fractures and injury-related articular cartilage damage. The healing process can be impaired resulting in non-unions in 5-10% of the bone fractures and in post-traumatic osteoarthritis (PTOA) in up to 75% of the cases of cartilage damage. Despite the amount of research performed in the areas of fracture healing and cartilage repair as well as non-unions and PTOA, still, the outcome of a bone fracture or articular cartilage damage cannot be predicted. Here, we discuss known risk factors and key molecules involved in the repair process, together with the main challenges associated with the prediction of outcome of these injuries. Furthermore, we review and discuss the opportunities for mass spectrometry (MS) - an analytical tool capable of detecting a wide variety of molecules in tissues - to contribute to extending molecular understanding of impaired healing and the discovery of predictive biomarkers. Therefore, the current knowledge and challenges concerning MS imaging of bone and cartilage tissue as well as in vivo MS are discussed. Finally, we explore the possibilities of in situ, real-time MS for the prediction of outcome during surgery of bone fractures and injury-related articular cartilage damage.

Skeletal maturation and growth rates are related to bone and growth plate injuries in adolescent athletics.

Injuries are common in elite adolescent athletics, but few studies have addressed risk factors for injury. Growth and maturation are potential risk factors in this population; however, the current body of literature is both inconclusive and considered at high risk of bias. The aim of this study was therefore to examine whether growth rate, maturity status, and maturity tempo are associated with injury risk in an elite sports academy. Anthropometric, skeletal maturity and injury data collected prospectively over four seasons (117 athlete-seasons) were included in the analyses. Growth rate for stature was associated with greater risk of bone (incidence rate ratio (IRR): 1.5 per one standard deviation increase above the mean; 95% CI: 1.1-1.9) and growth plate injuries (IRR: 2.1; 1.5-3.1). Growth rate for leg length was associated with greater overall injury risk (IRR: 1.3; 1.0-1.7) as well as the risk of bone (IRR: 1.4; 1.0-1.9) and growth plate injuries (IRR: 2.1; 1.4-3.0). Athletes with greater skeletal maturity, expressed as skeletal age (IRR: 0.6 per year; 0.5-0.9) and percentage of predicted mature height (IRR: 0.8 per percent increase; 0.7-1.0), were less prone to growth plate injuries. Rate of change in skeletal age was associated with an increased risk of bone injuries (IRR: 1.5; 1.0-2.3). The results of this study suggest that rapid growth in stature and leg length, skeletal maturity status, and maturity tempo represent risk factors for certain injury types in adolescent athletics.

Improvement of image quality applying iterative scatter correction for grid-less skeletal radiography in trauma room setting.

BACKGROUND: Iterative reconstruction is well established for CT. Plain radiography also takes advantage of iterative algorithms to reduce scatter radiation and improve image quality. First applications have been described for bedside chest X-ray. A recent experimental approach also provided proof of principle for skeletal imaging. PURPOSE: To examine clinical applicability of iterative scatter correction for skeletal imaging in the trauma setting. MATERIAL AND METHODS: In this retrospective single-center study, 209 grid-less radiographs were routinely acquired in the trauma room for 12 months, with imaging of the chest (n = 31), knee (n = 111), pelvis (n = 14), shoulder (n = 24), and other regions close to the trunk (n = 29). Radiographs were postprocessed with iterative scatter correction, doubling the number of images. The radiographs were then independently evaluated by three radiologists and three surgeons. A five-step rating scale and visual grading characteristics analysis were used. The area under the VGC curve (AUCVGC) quantified differences in image quality. RESULTS: Images with iterative scatter correction were generally rated significantly better (AUCVGC = 0.59, P < 0.01). This included both radiologists (AUCVGC = 0.61, P < 0.01) and surgeons (AUCVGC = 0.56, P < 0.01). The image-improving effect was significant for all body regions; in detail: chest (AUCVGC = 0.64, P < 0.01), knee (AUCVGC = 0.61, P < 0.01), pelvis (AUCVGC = 0.60, P = 0.01), shoulder (AUCVGC = 0.59, P = 0.02), and others close to the trunk (AUCVGC = 0.59, P < 0.01). CONCLUSION: Iterative scatter correction improves the image quality of grid-less skeletal radiography in the clinical setting for a wide range of body regions. Therefore, iterative scatter correction may be the future method of choice for free exposure imaging when an anti-scatter grid is omitted due to high risk of tube-detector misalignment.