The Validity of Muscle Ultrasound in the Diagnostic Workup of Sarcopenia Among Older Adults: A Scoping Review.

Purpose: Muscle ultrasound has emerged as a promising method in the diagnostic work-up of sarcopenia. The objective of this scoping review was to explore the validity of muscle ultrasound against the latest sarcopenia definitions among older adults. Methods: We adhered to the PRISMA guidelines for scoping reviews. A systematic search of databases was performed by two independent reviewers. All articles comparing the performance of ultrasound to an internationally acknowledged sarcopenia definition among older adults (≥60 years) and published between 2019/01/01 (the year updated sarcopenia definitions were introduced) and 2023/11/15 were included. Data were extracted and collated by muscle and muscle parameters. Results: Out of 2290 articles screened, six studies comprising 24 validity tests among a total of 1619 older adults (mean age 74.1 years, 52.2% female) were included. The validity tests investigated the rectus femoris (n = 7), biceps brachii (n = 5), gastrocnemius medialis (n = 4), tibialis anterior (n = 4), soleus (n = 3), and rectus abdominis (n = 1). The parameter muscle thickness (MT) (n = 14) was most commonly measured. The latest European and Asian sarcopenia definitions (EWGSOP2, AWGS2) were applied as reference standards in four validity tests each. None of the studies used the Sarcopenia Definition and Outcome Consortium (SDOC) criteria. The highest area under the curve AUC (0.92, 95% confidence interval [CI] 0.89-0.94) was found for the muscle thickness of the rectus femoris muscle. Due to substantial heterogeneity among the studies, pooling of data using a meta-analytic approach was not feasible. Conclusion: Limited number of studies have examined the validity of muscle ultrasound for diagnosing sarcopenia based on recent definitions among older adults. Thereby, muscle thickness of the rectus femoris showed promising results regarding validity. Further studies are needed to investigate the validity of key muscles and to validate muscle ultrasound among older hospitalized patients.

Definitions and adverse outcomes of sarcopenia in older patients in orthopedic and trauma care: A scoping review on current evidence.

PURPOSE: Sarcopenia, defined as the loss of muscle mass and strength, can hinder postoperative recovery and raise mortality rates. However, the current evidence on the harmful effects of sarcopenia in older patients in orthopedic and trauma care is unclear. This scoping review investigates different definitions that were used for the diagnosis of sarcopenia in older patients in orthopedic and trauma care and what adverse consequences have been examined. METHODS: We performed a comprehensive literature search in PubMed and Embase, following the PRISMA guidelines. We included original studies that examined clinical outcomes (such as length of hospital stay, rate of non-home discharge, rate of subsequent falls, rate of refractures, mortality, and functional outcome/quality of life) in older patients in orthopedic and trauma care (aged 65 years and above) with diagnosed sarcopenia (S) compared to a group without sarcopenia (NS). RESULTS: Our search identified 2,748 publications. Out of these, 23 articles met the inclusion criteria. Most publications were from Asia (n = 13). A total of 6174 patients were examined, with a prevalence of sarcopenia in 14-92%. 11 articles focused on patients with hip joint pathologies. Most studies diagnosed sarcopenia according to the Asian Working Group on Sarcopenia (AWGSOP1 or AWGSOP2) definitions (n = 10). Length of hospital stay was investigated in 13 studies. Seven studies assessed rates of non-home discharge rates. Subsequent falls were not investigated in any of the studies. 1 study reported the overall refracture rate (S: 10.4%; NS: 5.8%). Mortality was assessed in 11 studies (S: 1-60.5%; NS: 0-39.5%). The functional outcome/quality of life was investigated by 17 studies (Barthel Index decline S: -4.5 to -15.3 points; NS: -11.7 to -54.7 points). CONCLUSION: Sarcopenia has been increasingly studied in older patients in orthopedic and trauma care but there is a lack of consistent definition criteria. This scoping review suggests that sarcopenia may be associated with prolonged length of stay, higher rates of non-home discharge, and increased mortality among older patients in orthopedic and trauma care. However, prospective studies are necessary to establish the relationship between sarcopenia and refractures, falls, and functional outcome/quality of life among older patients in orthopedic and trauma care.

The influence of intervertebral disc overloading on nociceptor calcium flickering.

Introduction: Mechanical overloading can trigger a degenerative-like cascade in an organ culture of intervertebral disc (IVD). Whether the overloaded IVD can influence the activation of nociceptors (i.e., the damage sensing neurons) remains unknown. The study aims to investigate the influence of overloaded IVD conditioned medium (CM) on the activation of nociceptors. Methods: In the static loading regime, force-controlled loading of 0.2 MPa for 20 h/day representing "long-term sitting and standing" was compared with a displacement-controlled loading maintaining original IVD height. In the dynamic loading regime, high-frequency-intensity loading representing degenerative "wear and tear" was compared with a lower-frequency-intensity loading. CM of differently loaded IVDs were collected to stimulate the primary bovine dorsal root ganglion (DRG) cultures. Calcium imaging (Fluo-4) and calcitonin gene-related peptide (CGRP) immunofluorescent labeling were jointly used to record the calcium flickering in CGRP(+) nociceptors. Results: Force-controlled loading led to a higher IVD cell death compared to displacement-controlled loading. Both static and dynamic overloading (force-controlled and high-frequency-intensity loadings) elevated the frequency of calcium flickering in the subsurface space of CGRP(+) nociceptors compared to their mild loading counterparts. Conclusion: In the organ culture system, IVD overloading mediated an altered IVD-nociceptor communication suggesting a biological mechanism associated with discogenic pain.

Chemonucleolysis combined with dynamic loading for inducing degeneration in bovine caudal intervertebral discs.

Chemonucleolysis has become an established method of producing whole organ culture models of intervertebral disc (IVD) degeneration. However, the field needs more side-by-side comparisons of the degenerative effects of the major enzymes used in chemonucleolysis towards gaining a greater understanding of how these organ culture models mimic the wide spectrum of characteristics observed in human degeneration. In the current work we induced chemonucleolysis in bovine coccygeal IVDs with 100 µL of papain (65 U/mL), chondroitinase ABC (chABC, 5 U/mL), or collagenase II (col'ase, 0.5 U/mL). Each enzyme was applied in a concentration projected to produce moderate levels of degeneration. After 7 days of culture with daily dynamic physiological loading (0.02-0.2 MPa, 0.2 Hz, 2 h), the cellular, biochemical and histological properties of the IVDs were evaluated in comparison to a PBS-injected control. Papain and collagenase, but not chABC, produced macroscopic voids in the tissues. Compared to day 0 intact IVDs, papain induced the greatest magnitude glycosaminoglycan (GAG) loss compared to chABC and col'ase. Papain also induced the greatest height loss (3%), compared to 0.7%, 1.2% and 0.4% for chABC, col'ase, and PBS, respectively. Cell viability in the region adjacent to papain and PBS-injection remained at nearly 100% over the 7-day culture period, whereas it was reduced to 60%-70% by chABC and col'ase. Generally, enzyme treatment tended to downregulate gene expression for major ECM markers, type I collagen (COL1), type II collagen (COL2), and aggrecan (ACAN) in the tissue adjacent to injection. However, chABC treatment induced an increase in COL2 gene expression, which was significant compared to the papain treated group. In general, papain and col'ase treatment tended to recapitulate aspects of advanced IVD degeneration, whereas chABC treatment captured aspects of early-stage degeneration. Chemonucleolysis of whole bovine IVDs is a useful tool providing researchers with a robust spectrum of degenerative changes and can be utilized for examination of therapeutic interventions.

Osseous microarchitecture in frequent fracture zones of the distal clavicle.

Background: Fracture classifications of the distal clavicle are based on ligamentous integrity. The influence of osseous microarchitecture on fracture occurrence, morphology, and the lesion's stability has not yet been investigated. We aimed to characterize osseous microarchitecture according to common fracture classification systems based on ligamentous integrity and investigated the possible effects of age, gender, and osteoporosis in distal clavicle fractures. Methods: N = 20 human cadaveric distal clavicles were scanned using XtremeCT with an isometric voxel size of 82 µm. In the sagittal plane, each data set was evaluated in 11 sections of approximately 7 mm thickness. Three topographic regions were defined: the bone lateral to the trapezoid (LTR), intertubercular (ITR), and medial to the conoid (MCR) ligament. Cortical bone mineral density (BMD) [mgHA/cm3] and cortical porosity (1- (BV/TV) [%]) were determined and evaluated relative to age and gender. Results: Along the mediolateral axis, there was an >20-fold increase in median cortical porosity (P ≤ .001). There were significant differences in cortical porosity between LTR and ITR (P ≤ .001) but not between ITR and MCR (P = .09). In ITR, cortical porosity was significantly greater in >60-year-old compared to younger donors (P = .01). For BMD, there was an >2-fold decrease toward the distal apex (P ≤ .001). BMD was significantly greater in ITR compared to LTR (P ≤ .001) and in MCR compared to ITR (P = .02). In ITR and MCR, clavicles of >60-year-old donors had significantly lower BMD values compared to younger donors (P < .01). Across all 3 regions, frequency distribution of low bone mass did not significantly differ between <60-year-olds and >60-year-olds (P > .6). Conclusion: The distal clavicle features a characteristic bony microarchitecture. The present study revealed a significant difference in bone quality of lateral, intertubercular, and medial zones of the distal clavicle and could specify target areas and strategies for surgical treatment of unstable fractures. Age, gender, and osteoporosis have a limited effect on bone quality and fracture genesis. In contrast, ligamentous quality is supposed to exert a substantial influence on fracture characteristics, especially in ITR. Fracture morphology of the distal clavicle is determined by a bony-ligamentous conjunction, which remains to be characterized.

Effect of C-Clamp Application on Hemodynamic Instability in Polytrauma Victims with Pelvic Fracture.

Background and Objectives: C-clamp application may reduce mortality in patients with unstable pelvic fractures and hemodynamic instability. Decreasing C-clamp use over the past decades may have resulted from concerns about its effectiveness and safety. The purpose of this study was to document effective hemodynamic stabilization after C-clamp application by means of vital parameters (primary outcome parameter), and the subsequent effect on metabolic indices and volume management (secondary outcome parameters). Materials and Methods: C-clamp application was performed between 2014 and 2021 for n = 13 patients (50 ± 18 years) with unstable pelvic fractures and hemodynamic instability. Vital parameters, metabolic indices, volume management, and the correlation of factors and potential changes were analyzed. Results: After C-clamp application, increases were measured in systolic blood pressure (+15 mmHg; p = 0.0284) and mean arterial pressure (+12 mmHg; p = 0.0157), and a reduction of volume requirements (p = 0.0266) and bolus vasoactive medication needs (p = 0.0081) were observed. The earlier C-clamp application was performed, the greater the effect (p < 0.05; r > 0.6). Heart rate, shock index, and end-tidal CO2 were not significantly altered. The extent of base deficit, hemoglobin, and lactate did not correlate with changes in vital parameters. Conclusions: In the majority of hemodynamically unstable trauma patients not responding to initial fluid resuscitation and severe pelvic fracture, early C-clamp application had an additive effect on hemodynamic stabilization and reduction in volume substitution. Based on these findings, there is still a rationale for considering early C-clamp stabilization in this group of severely injured patients.

Characteristics of Prehospital Death in Trauma Victims.

BACKGROUND: Using Injury Severity Score (ISS) data, this study aimed to give an overview of trauma mechanisms, causes of death, injury patterns, and potential survivability in prehospital trauma victims. METHODS: Age, gender, trauma mechanism, cause of death, and ISS data were recorded regarding forensic autopsies and whole-body postmortem CT. Characteristics were analyzed for injuries considered potentially survivable at cutoffs of (I) ISS ≤ 75 vs. ISS = 75, (II) ISS ≤ 49 vs. ISS ≥ 50, and (III) ISS < lethal dose 50% (LD50) vs. ISS > LD50 according to Bull's probit model. RESULTS: In n = 130 prehospital trauma victims (45.3 ± 19.5 years), median ISS was 66. Severity of injuries to the head/neck and chest was greater compared to other regions (p < 0.001). 52% died from central nervous system (CNS) injury. Increasing injury severity in head/neck region was associated with CNS-injury related death (odds ratio (OR) 2.7, confidence interval (CI) 1.8-4.4). Potentially survivable trauma was identified in (I) 56%, (II) 22%, and (III) 9%. Victims with ISS ≤ 75, ISS ≤ 49, and ISS < LD50 had lower injury severity across most ISS body regions compared to their respective counterparts (p < 0.05). CONCLUSION: In prehospital trauma victims, injury severity is high. Lethal injuries predominate in the head/neck and chest regions and are associated with CNS-related death. The appreciable amount (9-56%) of victims dying at presumably survivable injury severity encourages perpetual efforts for improvement in the rescue of highly traumatized patients.

A Hyaluronan and Platelet-Rich Plasma Hydrogel for Mesenchymal Stem Cell Delivery in the Intervertebral Disc: An Organ Culture Study.

The purpose of the present pilot study was to evaluate the effect of a hydrogel composed of hyaluronic acid (HA) and platelet-rich plasma (PRP) as a carrier for human mesenchymal stem cells (hMSCs) for intervertebral disc (IVD) regeneration using a disc organ culture model. HA was mixed with batroxobin (BTX) and PRP to form a hydrogel encapsulating 1 × 106 or 2 × 106 hMSCs. Bovine IVDs were nucleotomized and filled with hMSCs suspended in ~200 µL of the PRP/HA/BTX hydrogel. IVDs collected at day 0 and nucleotomized IVDs with no hMSCs and/or hydrogel alone were used as controls. hMSCs encapsulated in the hydrogel were also cultured in well plates to evaluate the effect of the IVD environment on hMSCs. After 1 week, tissue structure, scaffold integration, hMSC viability and gene expression of matrix and nucleus pulposus (NP) cell markers were assessed. Histological analysis showed a better preservation of the viability of the IVD tissue adjacent to the gel in the presence of hMSCs (~70%) compared to the hydrogel without hMSCs. Furthermore, disc morphology was maintained, and the hydrogel showed signs of integration with the surrounding tissues. At the gene expression level, the hydrogel loaded with hMSCs preserved the normal metabolism of the tissue. The IVD environment promoted hMSC differentiation towards a NP cell phenotype by increasing cytokeratin-19 (KRT19) gene expression. This study demonstrated that the hydrogel composed of HA/PRP/BTX represents a valid carrier for hMSCs being able to maintain a good cell viability while stimulating cell activity and NP marker expression.

Spinal injury in alpine winter sports: a review.

INTRODUCTION: Alpine winter sports have become increasingly popular over recent decades, with a similar increase in accident incidence. This review provides an overview of the most recent literature concerning spinal injury epidemiology, mechanisms, patterns and prevention strategies in the context of alpine winter sports. MATERIAL AND METHODS: The PubMed, Cochrane Library, and EMBASE databases were searched using the keywords spine injury, alpine injury, spine fracture, skiing injuries, snowboard injuries. 64 published studies in English and German met a priori inclusion criteria and were reviewed in detail by the authors. RESULTS: There are various mechanisms of injury in alpine winter sports (high speed falls in skiing, jumping failure in snowboarding) whilst regionality and injury severity are broadly similar. The thoracolumbar spine is the most common region for spinal injury. Spinal cord injury is relatively rare, usually accompanying distraction and rotation type fractures and is most commonly localised to the cervical spine. Disc injuries seem to occur more commonly in alpine winter sport athletes than in the general population. DISCUSSION: Despite awareness of increasing rates and risks of spinal injuries in alpine winter sports, there has been little success in injury prevention.