Sodium and quantitative hydrogen parameter changes in muscle tissue after eccentric exercise and in delayed-onset muscle soreness assessed with magnetic resonance imaging.

The objective of the current study was to assess sodium (23 Na) and quantitative proton (1 H) parameter changes in muscle tissue with magnetic resonance imaging (MRI) after eccentric exercise and in delayed-onset muscle soreness (DOMS). Fourteen participants (mean age: 25 ± 4 years) underwent 23 Na/1 H MRI of the calf muscle on a 3-T MRI system before exercise (t0), directly after eccentric exercise (t1), and 48 h postintervention (t2). In addition to tissue sodium concentration (TSC), intracellular-weighted sodium (ICwS) signal was acquired using a three-dimensional density-adapted radial projection readout with an additional inversion recovery preparation module. Phantoms containing saline solution served as references to quantify sodium concentrations. The 1 H MRI protocol consisted of a T1 -weighted turbo spin echo sequence, a T2 -weighted turbo inversion recovery, as well as water T2 mapping and water T1 mapping. Additionally, blood serum creatine kinase (CK) levels were assessed at baseline and 48 h after exercise. The TSC and ICwS of exercised muscles increased significantly from t0 to t1 and decreased significantly from t1 to t2. In the soleus muscle (SM), ICwS decreased below baseline values at t2. In the tibialis anterior muscle (TA), TSC and ICwS remained at baseline levels at each measurement point. However, high-CK participants (i.e., participants with a more than 10-fold CK increase, n = 3) displayed different behavior, with 2- to 4-fold increases in TSC values in the medial gastrocnemius muscle (MGM) at t2. 1 H water T1 relaxation times increased significantly after 48 h in the MGM and SM. 1 H water T2 relaxation times and muscle volume increased in the MGM at t2. Sodium MRI parameters and water relaxation times peaked at different points. Whereas water relaxation times were highest at t2, sodium MRI parameters had already returned to baseline values (or even below baseline values, for low-CK participants) by this point. The observed changes in ion concentrations and water relaxation time parameters could enable a better understanding of the physiological processes during DOMS and muscle regeneration. In the future, this might help to optimize training and to reduce associated sports injuries.

Effects of exercise and cold-water exposure on microvascular muscle perfusion.

PURPOSE: Microvascular blood flow (MBF) and its intramuscular regulation are of importance for physiological responsiveness and adaptation. The quantifiable in-vivo monitoring of MBF after cycling or systemic cold-water exposure may reveal new insights into capillary regulatory mechanisms. This study aimed to assess the role of exercise and cold therapy on MBF by using contrast-enhanced ultrasound (CEUS). METHODS: Twenty healthy athletes were recruited and randomly assigned to an intervention (IG) or a control group (CG). MBF was quantified in superficial (rectus femoris, RF) and deep muscle layers (vastus intermedius, VI). Representative perfusion parameters (peak enhancement (PE) and wash-in area under the curve (WiAUC)) were measured after a standardized measurement protocol for both groups at resting conditions (t0) and after cycling (20 min., 70% Watt max, t1) for both groups, after cold-water immersion exposure for IG (15 min., 12°C) or after precisely 15 minutes of rest for CG (t2) and for both groups after 60 minutes of follow-up (t3). RESULTS: At t1, MBF in VI increased significantly compared to resting conditions in both groups in VI (p= 0.02). After the cold-water exposure (t2), there were no statistically significant changes in perfusion parameters as well as after 60 minutes of follow-up (t3) (p = 0.14). CONCLUSION: Cycling leads to an upregulation of MBF. However, cold exposure does not change the MBF. The implementation of CEUS during different physiological demands may provide deeper insight into intramuscular perfusion regulation and regenerative processes.

Effect of compression garments on muscle perfusion in delayed-onset muscle soreness: A quantitative analysis using intravoxel incoherent motion MR perfusion imaging.

The aim of this prospective cohort study was to evaluate the effect of compression garments under resting conditions and after the induction of delayed-onset muscle soreness (DOMS) by MR perfusion imaging using intravoxel incoherent motion (IVIM). Magnetic resonance imaging of both lower legs of 16 volunteers was performed before and after standardized eccentric exercises that induced DOMS. A compression garment (21-22 mmHg) was worn during and for 6 h after exercise on one randomly selected leg. IVIM MR imaging, represented as total muscle perfusion D*f, perfusion fraction f and tissue diffusivity D, were compared between baseline and directly, 30 min, 6 h and 48 h after exhausting exercise with and without compression. Creatine kinase levels and T2-weighted images were acquired at baseline and after 48 h. DOMS was induced in the medial head of the gastrocnemius muscle (MGM) in all volunteers. Compression garments did not show any significant effect on IVIM perfusion parameters at any time point in the MGM or the tibialis anterior muscle (p > 0.05). Microvascular perfusion in the MGM increased significantly in both the compressed and noncompressed leg between baseline measurements and those taken directly after and 30 min after the exercise: the relative median f increased by 31.5% and 24.7% in the compressed and noncompressed leg, respectively, directly after the exercise compared with the baseline value. No significant change in tissue perfusion occurred 48 h after the induction of DOMS compared with baseline. It was concluded that compression garments (21-22 mmHg) do not alter microvascular muscle perfusion at rest, nor do they have any significant effect during the regeneration phase of DOMS. In DOMS, only a short-term effect of increased muscle perfusion (30 min after exercise) was observed, with normalization occurring during regeneration after 6-48 h. The normalization of perfusion independently of compression after 6 h may have implications for diagnostic and therapeutic strategies and for the better understanding of pathophysiological pathways in DOMS.

Different Effects of Foam Rolling on Passive Tissue Stiffness in Experienced and Nonexperienced Athletes.

CONTEXT: Foam rolling (FR) has been developed into a popular intervention and has been established in various sports disciplines. However, its effects on target tissue, including changes in stiffness properties, are still poorly understood. OBJECTIVE: To investigate muscle-specific and connective tissue-specific responses after FR in recreational athletes with different FR experience. DESIGN: Case series. SETTING: Laboratory environment. PARTICIPANTS: The study was conducted with 40 participants, consisting of 20 experienced (EA) and 20 nonexperienced athletes (NEA). INTERVENTION: The FR intervention included 5 trials per 45 seconds of FR of the lateral thigh in the sagittal plane with 20 seconds of rest between each trial. MAIN OUTCOME MEASURES: Acoustic radiation force impulse elastosonography values, represented as shear wave velocity, were obtained under resting conditions (t0) and several times after FR exercise (0 min [t1], 30 min [t2], 6 h [t3], and 24 h [t4]). Data were assessed in superficial and deep muscle (vastus lateralis muscle; vastus intermedius muscle) and in connective tissue (iliotibial band). RESULTS: In EA, tissue stiffness of the iliotibial band revealed a significant decrease of 13.2% at t1 (P ≤ .01) and 12.1% at t3 (P = .02). In NEA, a 6.2% increase of stiffness was found at t1, which was not significantly different to baseline (P = .16). For both groups, no significant iliotibial band stiffness changes were found at further time points. Also, regarding muscle stiffness, no significant changes were detected at any time for EA and NEA (P > .05). CONCLUSIONS: This study demonstrates a significant short-term decrease of connective tissue stiffness in EA, which may have an impact on the biomechanical output of the connective tissue. Thus, FR effects on tissue stiffness depend on the athletes' experience in FR, and existing studies have to be interpreted cautiously in the context of the enrolled participants.

Trefoil Factor 3 (TFF3) Is Involved in Cell Migration for Skeletal Repair.

The aim of the study was to explore the possible role of Trefoil Factor Family peptide 3 (TFF3) for skeletal repair. The expression of TFF3 was analyzed in human joint tissues as well as in a murine bone fracture model. Serum levels of TFF3 following a defined skeletal trauma in humans were determined by ELISA. The mRNA expression of TFF3 was analyzed under normoxia and hypoxia. Expression analysis after stimulation of human mesenchymal progenitor cells (MPCs) with TFF3 was performed by RT2 Profiler PCR Array. The effect of recombinant human (rh)TFF3 on MPCs was analysed by different migration and chemotaxis assays. The effect on cell motility was also visualized by fluorescence staining of F-Actin. TFF3 was absent in human articular cartilage, but strongly expressed in the subchondral bone and periosteum of adult joints. Strong TFF3 immunoreactivity was also detected in murine fracture callus. Serum levels of TFF3 were significantly increased after skeletal trauma in humans. Expression analysis demonstrated that rhTFF3 significantly decreased mRNA of ROCK1. Wound healing assays showed increased cell migration of MPCs by rhTFF3. The F-Actin cytoskeleton was markedly influenced by rhTFF3. Cell proliferation was not increased by rhTFF3. The data demonstrate elevated expression of TFF3 after skeletal trauma. The stimulatory effects on cell motility and migration of MPCs suggest a role of TFF3 in skeletal repair.

Evaluation of Rock Climbing Related Injuries in Older Athletes.

INTRODUCTION: With the growing enthusiasm from people of all ages about rock climbing and bouldering, adaptions and medical conditions of the older athlete have become increasingly important. We aimed to analyze injury demographics, distribution, and severity for the older rock-climbing athlete. METHODS: During a 3-y period, we performed a single-center injury surveillance in athletes ≥35 y of age presenting with rock climbing-related injuries or complaints. A standard questionnaire and examination protocol were conducted. RESULTS: A total of 198 patients (age 44.2±7.1 [35-77] y) (mean±SD, with range) with 275 independent injuries were recorded. Ninety percent of all injuries affected the upper extremity, 6% the lower extremity, and 4% other body regions. The Union Internationale des Associations d'Alpinisme injury scores were 2.0±0.3 (1-4), and no fatalities occurred. Acute injuries were observed in 32% and overuse injuries in 68% of all injuries. Among the overuse injuries, 47% were classified as degenerative overuse conditions. Athlete age did not significantly correlate with the development of overuse injuries and UIAA injury score, but subgroup analysis showed a weak correlation of the climber age with the development of degenerative conditions (P<0.05). The leading diagnosis of degenerative conditions was subacromial impingement syndrome of the shoulder. CONCLUSIONS: Compared to younger athletes, older rock climbers demonstrate a higher proportion of overuse injuries, especially degenerative conditions. Profound knowledge of climbing injuries patterns and conditions in older rock climbers is crucial to prevent injuries among all age groups and to decrease the number of degenerative injuries.

Compartment Syndrome of the Foot: An Evidence-Based Review.

Compartment syndrome of the foot (CSF) is a surgical emergency, with high risk of morbidity and poor outcome, including persistent neurologic deficits or amputation. Uncertainty remains regarding surgical approaches, pressure monitoring values, and the extent of surgical treatment. This review provides a summary of the current knowledge and reports evidence-based diagnostic and therapeutic management options for CSF. Articles describing CSF were identified from MEDLINE, PubMed, and Cochrane databases up until February 2018. Experimental and original articles, systematic and nonsystematic reviews, case reports, and book chapters, independent of their level of evidence, were included. Crush injuries are the leading cause of CSF, but CSF can present after fractures of the tarsal or metatarsal bones and dislocations of the Lisfranc or Chopart joints. CSF is often associated with persistent neurologic deficits, claw toes, amputations, and skin healing problems. Diagnosis is made after accurate clinical evaluation combined with intracompartmental pressure monitoring. A threshold value of <20 mmHg difference between the diastolic blood pressure and the intracompartmental pressure is considered diagnostic. Management consists of surgery, whereby 2 dorsal incisions are combined with a medioplantar incision to the calcaneal compartment. The calcaneal compartment can serve as an "indicator compartment," as the highest-pressure values can regularly be measured within this compartment. Appropriately powered studies of CSF are necessary to further evaluate and compare diagnostic and therapeutic options.

Healing Response of a Structural Hamstring Injury: Perfusion Imaging 8-Week Follow-Up.

CONTEXT: Hamstring injuries are frequently observed in various sports disciplines both in elite and recreational sport. OBJECTIVE: To quantify intramuscular tissue perfusion via contrast-enhanced ultrasound in the acute phase and during the healing of a structural muscle injury confirmed by high-resolution magnetic resonance imaging. DESIGN: Case study. SETTING: Laboratory environment. PATIENT: A 32-year-old wakeboarder (height = 176 cm, body weight = 76 kg, and body mass index = 24.5 kg/m2) with an acute indirect muscle injury of the semimembranosus muscle. MAIN OUTCOME MEASURES: Average values of quantifiable contrast-enhanced ultrasound, represented as peak enhancement and wash-in area under the curve, as well as conventional ultrasound, 1.5T magnetic resonance imaging were assessed at 48-hour, 3-week, and 8-week postinjury. RESULTS: Average values of the quantitative perfusion analysis at 48-hour and 8-week postinjury revealed an approximate 5-fold increase in peak enhancement, and the wash-in area under the curve increased more than 3-fold in the center of the lesion. Magnetic resonance imaging, performed 48 hours after the injury to gather reference data as gold standard, revealed a grade III structural muscle tear. CONCLUSIONS: The authors are able to demonstrate significant changes in intramuscular tissue perfusion in the center of the structural lesion as well as in the adjacent tissue. Quantifiable contrast-enhanced ultrasound seems to be able to gather relevant data for the assessment and monitoring of muscle injuries and could be established as a valuable tool for further studies focusing on healing processes or therapeutic interventions.

Contrast-Enhanced Ultrasound as a New Investigative Tool in Diagnostic Imaging of Muscle Injuries-A Pilot Study Evaluating Conventional Ultrasound, CEUS, and Findings in MRI.

OBJECTIVE: To emphasize the diagnostic value of contrast-enhanced ultrasound (CEUS) in the imaging of muscle injuries with different degrees of severity by comparing findings to established imaging modalities such as conventional ultrasound and magnetic resonance imaging (MRI). DESIGN: Case series. SETTING: Institutional study. Conventional ultrasound and CEUS were performed in the Department of Internal Medicine. Magnetic resonance imaging was carried out in the Department of Radiology within the Magnetom Avanto 1.5T and Magnetom Skyra fit 3T (Siemens Healthineers, Erlangen, Germany) and in the Institution of Imaging Diagnostics and Therapy (Magnetom Avanto 1.5T; Siemens, Erlangen, Germany). PATIENTS: Fifteen patients who underwent an acute muscle injury were recruited. MAIN OUTCOME MEASURES: The appearance and detectable size of muscle injuries were compared between each imaging modality. The injuries were assessed by 3 independent observers and blinded between imaging modalities. RESULTS: All 15 injuries were identified on MRI and CEUS, whereas 10 injuries showed abnormalities in conventional ultrasound. The determination and measurement revealed significant differences between conventional ultrasound and CEUS depending on injury severity. Contrast-enhanced ultrasound revealed an impairment of microcirculation in grade I lesions (corresponding to intramuscular edema observed in MRI), which was not detectable using conventional ultrasound. CONCLUSIONS: Our results indicate that performing CEUS seems to be a sensitive additional diagnostic modality in the early assessment of muscle injuries. Our results highlight the advantages of CEUS in the imaging of low-grade lesions when compared with conventional ultrasound, as this was the more accurate modality for identifying intramuscular edema.

Application of Acoustic Radiation Force Impulse Elastography in Imaging of Delayed Onset Muscle Soreness: A Comparative Analysis With 3T MRI.

CONTEXT: Delayed onset muscle soreness is one of the most common reasons for impaired muscle performance in sports and is associated with reduced muscle strength and frequently observed both in professional and recreational athletes. OBJECTIVE: To emphasize the diagnostic value of acoustic radiation force impulse (ARFI) in imaging of delayed onset muscle soreness by comparing findings with high-resolution 3T magnetic resonance imaging T2-weighted sequences. DESIGN: Case series. SETTING: Laboratory environment. PARTICIPANTS: Fifteen healthy students (7 females and 8 males; mean [SD]: age 24 [4] y, height 178 [10] cm, body weight 67 [12] kg). MAIN OUTCOME MEASURES: ARFI values, represented as shear wave velocities of the gastrocnemius muscle and soleus muscle, as well as conventional ultrasound, high-resolution 3T magnetic resonance imaging, creatine kinase activity, extension range of the ankle joint, calf circumference, and muscle soreness were assessed before (baseline) and 60 hours after (postintervention) a standardized eccentric exercise. RESULTS: ARFI shear wave velocity values of the gastrocnemius muscle revealed a statistically significant decrease of 19.1% between baseline (2.2 [0.26] m/s) and postintervention (1.78 [0.24] m/s); P = .01. At follow-up, the magnetic resonance imaging investigations showed intramuscular edema for the gastrocnemius muscle in all participants corresponding to a significant raise in T2 signal intensity (P = .001) and in T2-time values (P = .004). CONCLUSIONS: ARFI elastography seems to be an additional sensitive diagnostic modality in the diagnostic workup of delayed onset muscle soreness. Intramuscular shear wave velocities could represent an additional imaging marker for the assessment and monitoring of ultrastructural muscle injuries and therefore be helpful for individual training composition in elite sports.

Effect of Compression Garments on the Development of Edema and Soreness in Delayed-Onset Muscle Soreness (DOMS).

Delayed-onset muscle soreness (DOMS), an ultrastructural muscle injury, is one of the most common reasons for impaired muscle performance. The purpose of this study was to investigate the influence of sport compression garments on the development of exercise-induced intramuscular edema in the context of DOMS. DOMS was induced in 15 healthy participants. The participants performed a standardized eccentric exercise of the calf muscles. Magnetic resonance imaging (MRI) was performed at baseline and 60h after exercise (T2-weighted signal intensity and T2 relaxation time was evaluated in each compartment and the intramuscular edema in the medial head of the gastrocnemius muscle was segmented). After the exercise, a conventional compression garment (18-21 mmHg) was placed on one randomized calf for 60h. The level of muscle soreness was evaluated using a visual analogue pain scale. T2-weighted signal intensity, T2 relaxation time and intramuscular edema showed a significant interaction for time with increased signal intensities/intramuscular edema in the medial head of the gastrocnemius muscle at follow-up compared to baseline. No significant main effect for compression or interaction between time and limb occurred. Further, no significant differences in the soleus muscle and the lateral head of the gastrocnemius muscle were noted between limbs or over time. After exercise, there was significantly increased muscle soreness in both lower legs in resting condition and when going downstairs and a decreased range of motion in the ankle joint. No significant difference was observed between the compressed and the non-compressed calf. Our results indicate that wearing conventional compression garments after DOMS has been induced has no significant effect on the development of muscle edema, muscle soreness, range of motion and calf circumference.

Intramuscular Perfusion Response in Delayed Onset Muscle Soreness (DOMS): A Quantitative Analysis with Contrast-Enhanced Ultrasound (CEUS).

The purpose of this study was to analyse intramuscular perfusion response in ultrastructural muscle lesions, by applying contrast-enhanced ultrasound (CEUS) to a delayed onset muscle soreness (DOMS) model. Results of this analysis were compared to high-resolution 3 Tesla MRI T2-weighted sequences. 14 healthy participants were recruited. Average perfusion parameters, represented as Peak enhancement (contrast agent inflow) and wash-in area under curve (WiAUC) of the gastrocnemius (GM) and soleus muscle (SM) were assessed before (baseline) and 60 h after inducing DOMS by eccentric exercise. Additionally, conventional ultrasound, high-resolution 3T MRI, creatine kinase level, range of motion (ROM) of the ankle joint, calf circumference and muscle soreness data were collected. Perfusion quantification revealed a statistically significant increase of intramuscular perfusion, corresponding to an increase in peak enhancement of 129.6% (p=0.0031) and in WiAUC of 115.2% (p=0.0107) in the gastrocnemius muscle at post-intervention. At follow-up, the MRI investigations showed intramuscular oedema for GM in all participants corresponding to a significant rise in T2 signal intensity (p=0.001) and in T2 time value (p=0.005). CEUS seems to be able to detect intramuscular perfusion changes and therefore may contribute to gaining deeper insight into the histopathology, inflammatory reactions and regeneration processes of ultrastructural muscle lesions.

Acute Effects of Lateral Thigh Foam Rolling on Arterial Tissue Perfusion Determined by Spectral Doppler and Power Doppler Ultrasound.

Hotfiel, T, Swoboda, B, Krinner, S, Grim, C, Engelhardt, M, Uder, M, and Heiss, R. Acute effects of lateral thigh foam rolling on arterial tissue perfusion determined by spectral Doppler and power Doppler ultrasound. J Strength Cond Res 31(4): 893-900, 2017-Foam rolling has been developed as a popular intervention in training and rehabilitation. However, evidence on its effects on the cellular and physiological level is lacking. The aim of this study was to assess the effect of foam rolling on arterial blood flow of the lateral thigh. Twenty-one healthy participants (age, 25 ± 2 years; height, 177 ± 9 cm; body weight, 74 ± 9 kg) were recruited from the medical and sports faculty. Arterial tissue perfusion was determined by spectral Doppler and power Doppler ultrasound, represented as peak flow (Vmax), time average velocity maximum (TAMx), time average velocity mean (TAMn), and resistive index (RI), and with semiquantitative grading that was assessed by 4 blindfolded investigators. Measurement values were assessed under resting conditions and twice after foam rolling exercises of the lateral thigh (0 and 30 minutes after intervention). The trochanteric region, mid portion, and distal tibial insertion of the lateral thigh were representative for data analysis. Arterial blood flow of the lateral thigh increased significantly after foam rolling exercises compared with baseline (p ≤ 0.05). We detected a relative increase in Vmax of 73.6% (0 minutes) and 52.7% (30 minutes) (p < 0.001), in TAMx of 53.2% (p < 0.001) and 38.3% (p = 0.002), and in TAMn of 84.4% (p < 0.001) and 68.2% (p < 0.001). Semiquantitative power Doppler scores at all portions revealed increased average grading of 1.96 after intervention and 2.04 after 30 minutes compared with 0.75 at baseline. Our results may contribute to the understanding of local physiological reactions to self-myofascial release.

Incompliance of total hip arthroplasty (THA) patients to limited weight bearing.

INTRODUCTION: Limited weight bearing of the lower extremity is a commonly applied procedure in orthopedic rehabilitation following trauma surgery and joint replacement. The compliance of patients with limited weight bearing after cementless total hip arthroplasty has not yet been surveyed using sensor-loaded insoles. The objective of this study was to investigate foot loadings in patients after THA under the assumption of limited weight bearing. METHODS: Peak pressures for the hindfoot, midfoot and forefoot were obtained from 14 patients (10 women, 4 men, age 63 ± 12 years, height 172 ± 9 cm, weight 92 ± 20 kg, BMI 31 ± 6 kg/m(2)) by means of dynamic pedobarography, with full weight bearing preoperatively (baseline) and at 8-10 days after cementless total hip arthroplasty, walking again on even floor, and also walking upstairs and downstairs with a restriction of weight bearing to 10 % body weight, taught by an experienced physiotherapist with a bathroom scale. RESULTS: Foot loadings with limited weight bearing on even floor remained up to 88 % from full weight bearing preoperatively. Walking upstairs and downstairs under the same condition was approximately equal to a bisection of peak pressures from full weight bearing. CONCLUSIONS: Patients following cementless do not comply with limited weight bearing when they are trained by the use of a bathroom scale.

Pathogenesis and Diagnosis of Proximal Hamstring Tendinopathies.

The proximal hamstring complex is a highly vulnerable area that is especially prone to injury. Proximal hamstring tendinopathies (PHTs) remain challenging in diagnosis, treatment, rehabilitation, and prevention due to a large variety of different injuries, slow healing response, persistent symptoms, and functional impairments. PHTs are often misdiagnosed or underdiagnosed, leading to delayed treatment and therapy failure. In addition, many athletes are at a high risk of PHT recurrence, a leading cause of prolonged rehabilitation and impaired individual performance. Until now, there have been no clear criteria for the diagnosis and classification of PHT. Tendinopathies can be graded based on their symptoms and onset. Additionally, radiological characteristics exist that describe the severity of tendinopathies. The diagnosis usually includes a battery of pain provocation tests, functional tests, and imaging to ensure a proper classification. Understanding the specific tasks in the pathogenesis and diagnostic process of PHT requires knowledge of functional anatomy, injury pattern and pathophysiological mechanisms as well as examination and imaging techniques. This work provides a structured overview of the pathogenesis and diagnostic work-up of PHT, emphasizing structured examination and imaging to enable a reliable diagnosis and rapid treatment decisions.

Suitability of Slaughterhouse-Acquired Pig Eyes as Model Systems for Refractive Ultraviolet and Infrared Femtosecond Laser Research.

PURPOSE: To elucidate whether it is feasible to use porcine eyes from scalded, abattoir-acquired animals for refractive femtosecond laser research. METHODS: An infrared laser (FS 200) and an ultraviolet laser (prototype version) were tested for their applicability on scalded pig eyes. Fifty porcine eyes were divided into two equally-sized groups and assigned to either the infrared or the ultraviolet laser. Both laser groups were comprised of five subgroups of n = 5 eyes each. Group A: non-scalded eyes (negative control); group B: eyes taken from tunnel-scalded animals; group C1: eyes taken from tank-scalded animals without opaque corneal lesion; group C2: eyes taken from animals with opaque corneal lesion; group D: eyes scalded in toto in the laboratory (positive control). In each group the lasers were employed to create a stromal flap. The quality of the laser cuts and the resulting flap beds, as well as of the porcine corneas themselves, was examined by anterior segment optical coherence tomography and scanning electron microscopy. RESULTS: All scalded specimens exhibited substantial corneal swelling, most pronounced in group C2. After ultraviolet laser application, the tank- and tunnel-scalded samples displayed marked irregularities and an increased degree of surface roughness in the flap beds. After infrared laser application, this was only the case in the tank-scalded specimens. CONCLUSION: It is not recommended to use eyes taken from scalded pigs for ultraviolet femtosecond laser experiments. For infrared femtosecond lasers, eyes taken from tunnel-scalded animals may represent an acceptable alternative, if non-scalded eyes are not available.

Importance of heat therapy in the treatment of pain in the daily clinical practice.

BACKGROUND: Musculoskeletal (MSK) pain includes a wide variety of causes and conditions. Despite the heterogeneity of MSK pain, it is possible to identify some common clinical features and treatments. Heat therapy (HT) is one of the most common and could be a suitable non-pharmacological approach. OBJECTIVE: To obtain a European overview on the use of non-pharmacological approaches and the role of heat therapy in the treatment of MSK pain. METHODS: Through a two-cycle Delphi-like method, an international board of experts reached a consensus on 13 questions for a survey to healthcare professionals who provide direct patient care. Between November 2021 and January 2022, the resulting web survey was distributed to professionals with the collaboration of ten European scientific societies and associations. Univariate and bivariate analyses were performed on collected data. RESULTS: Two hundred eighty-two answers were validated. Most of the respondents had extensive professional experience. Participants were widely distributed throughout Europe. HT is administered to about 50% of patients, with a higher percentage administered to those affected by low back pain (92%) and neck pain (84%). The choice of exogenous HT is based on both personal clinical experience and scientific evidence. HT is primarily chosen due to its relaxation effect, high safety profile and enhancement of tissue perfusion. The use of HT is recommended by 86.5% of respondents. CONCLUSION: Experts indicate that exogenous HT represents a valid therapeutic choice and is widely used in Europe. Patients should be informed about the use of heat therapy as a valuable self-management therapy option.

Moderate evidence exists for four microRNAs as potential biomarkers for tendinopathies and degenerative tendon ruptures at the upper extremity in elderly patients: conclusion of a systematic review with best-evidence synthesis.

PURPOSE: The aim of this systematic review was to investigate tendon-specific microRNAs (miRNAs) as biomarkers for the detection of tendinopathies or degenerative tendon ruptures. Also, their regulatory mechanisms within the tendon pathophysiology were summarized. METHODS: A systematic literature research was performed using the PRISMA guidelines. The search was conducted in the Pubmed database. The SIGN checklist was used to assess the study quality of the included original studies. To determine the evidence and direction of the miRNA expression rates, a best-evidence synthesis was carried out, whereby only studies with at least a borderline methodological quality were considered for validity purposes. RESULTS: Three thousand three hundred seventy studies were reviewed from which 22 fulfilled the inclusion criteria. Moderate evidence was found for miR-140-3p and miR-425-5p as potential biomarkers for tendinopathies as well as for miR-25-3p, miR-29a-3p, miR-140-3p, and miR-425-5p for the detection of degenerative tendon ruptures. This evidence applies to tendons at the upper extremity in elderly patients. All miRNAs were associated with inflammatory cytokines as interleukin-6 or interleukin-1ß and tumor necrosis factor alpha. CONCLUSIONS: Moderate evidence exists for four miRNAs as potential biomarkers for tendinopathies and degenerative tendon ruptures at the upper extremity in elderly patients. The identified miRNAs are associated with inflammatory processes.

What makes an orthopaedic paper highly citable? A bibliometric analysis of top orthopeadic journals with 10-year follow up.

PURPOSE: To examine a series of papers from top ranked orthopaedic journals with respect to the number of citations over a 10-year observation period to identify factors that lead to high citation rates. METHODS: The Web of Science database was consulted to identify all published papers from the first-year term of 2010 (January-May) from four top orthopaedic journals: AJSM, Arthroscopy, JBJS Am and KSSTA. The database was used to analyze and compare the papers with respect to their characteristics and citations up to 2019. Basic information for each paper was collected including the author, country, study type and average citations per year (ACY). The most (Top20%) and least (Bottom20%) frequently cited papers were identified and differences were extracted. RESULTS: Five hundred sixteen papers were included with a total of 19,261 citations. Most of the published papers were from the United States (n = 245). On average, a paper received 37.3 citations over the 10-year observation period. The most cited paper was cited 322 times. The most cited study type was randomized controlled trial (RCT) (Ø80.8). The Top20% papers were cited 37 times more often than the Bottom20%. Among the Top20%, the largest group was cohort study (n = 20) followed by case series (n = 19). Among others, the number of authors, the number of keywords and the number of references significantly correlated with the number of citations (p < 0.001). CONCLUSIONS: Factors influencing citation frequency were identified.

[Imaging of muscle injuries in sports medicine]. / Bildgebung von Muskelverletzungen im Sport.

BACKGROUND: Early diagnosis of muscle injuries is indispensable in order to initiate appropriate treatment and to facilitate optimal healing. PURPOSE: The aim of this review is to provide an update on imaging of muscle injuries in sports medicine with a focus on ultrasound and magnetic resonance imaging (MRI) and to present experimental approaches in addition to routine diagnostic procedures. MATERIALS AND METHODS: A PubMed literature search for the years 2012-2022 using the following keywords was performed: muscle, muscle injury, muscle imaging, muscle injury classification, delayed onset muscle soreness, ultrasound, MRI, sodium MRI, potassium MRI, ultra-high-field MRI, injuries of athletes. RESULTS: Imaging is crucial to confirm and assess the extent of sports-related muscle injuries and may help establishing treatment decisions, which directly affect the prognosis. This is of importance when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be necessary. In addition to established methods such as B­mode ultrasound and 1H­MRI, individual studies show promising approaches to further improve the imaging of muscle injuries in the future. Prior to the integration of contrast-enhanced ultrasound and X­nuclei into clinical routine, additional studies are needed to validate these techniques further. CONCLUSION: B­mode ultrasound represents an easily available, cost-effective modality for the initial diagnosis of muscle injuries. MRI is still considered the reference standard and enables an accurate morphological assessment of the extent of the injury. There are still no imaging approaches available for the objective determination of the optimal point of return to play.