Search

Jonas Krueckel,1 Dominik Szymski,1 Julia Lenz,1 Julian Fluegel,2 Johannes Weber,1 Leonard Achenbach,3 Rainer Meffert,4 Volker Alt,1 Kai Fehske4,5 1Department of Trauma Surgery, University Medical Center Regensburg, Regensburg, Germany; 2Department of Orthopaedic Surgery, Arcus Clinics Pforzheim, Pforzheim, Germany; 3Department of Orthopaedic Surgery, Koenig Ludwig Haus Wuerzburg, Wuerzburg, Germany; 4Department of Trauma Surgery, University Hosptial Wuerzburg, Wuerzburg, Germany; 5Department of Orthopedic and Trauma Surgery, Johanniter Waldkrankenhaus Bonn, Bonn, GermanyCorrespondence: Kai Fehske, Department of Orthopedic and Trauma Surgery, Johanniter Waldkrankenhaus Bonn, Waldstraße 73, Bonn, 53177, Germany, Email Fehske_k@ukw.de Jonas Krueckel, Department of Trauma Surgery, University Medical Center Regensburg, Regensburg, Germany, Email jonas.krueckel@ukr.dePurpose: While injuries among elite tennis athletes are extensively documented, a notable research gap exists regarding tennis injuries among club-level players. This study examines tennis injuries in German league players, with a particular emphasis on the impact of racquet properties and court surfaces, distinguishing between chronic and acute injuries.Patients and Methods: Retrospectively analyzing data from 600 tennis players over a 1.5-year period, a standardized questionnaire covered anthropometrics, injury characteristics, equipment usage, and court surface conditions.Results: The study identified 1012 tennis-related injuries, averaging 1.7 per player. Acute injuries predominantly affected the lower extremity (56%), with ankle injuries being the most prevalent, and ligaments were the most commonly affected structures (36.4%). Chronic complaints (reported by 364 athletes) focused on the upper extremity (63.2%), primarily tendon injuries (56.8%). Racket properties exhibited no significant impact on chronic upper extremity injuries.Conclusion: This study highlights a high incidence of acute lower extremity injuries, especially ankle ligament injuries, among German league tennis players. It offers crucial insights for devising targeted injury prevention strategies applicable to amateur, semi-professional, and professional tennis players, despite finding no significant link between racquet material and chronic upper extremity injuries.Keywords: tennis, injury, epidemiology, court surface, racquet material, ankle, ligament

Dominik Szymski,1 Leonard Achenbach,2,3 Martin Siebentritt,4 Karola Simoni,5 Norbert Kuner,5 Christian Pfeifer,1 Werner Krutsch,1,6 Volker Alt,1 Rainer Meffert,2 Kai Fehske2 1Department of Trauma Surgery, University Medical Centre Regensburg, Regensburg, Germany; 2Department of Trauma-, Hand-, Plastic- and Reconstructive Surgery, University Wuerzburg, Wuerzburg, Germany; 3Department of Orthopaedics, Koenig-Ludwig-Haus, University Wuerzburg, Wuerzburg, Germany; 4Department for Anesthesiology and Operative Intensive Care, Bayreuth, Germany; 5General Medicine and Dermatology, Medical Center for General Medicine, Dermatology, Paediatrics and Internal Medicine, Costa Calma Fuerteventura, Costa Calma, Spain; 6Sports-Orthopedics, SportDocs Franken, Nuremberg, GermanyCorrespondence: Kai FehskeDepartment of Trauma-, Hand-, Plastic- and Reconstructive Surgery, University Wuerzburg, Wuerzburg, GermanyTel +49 931 201 37001Fax +49 931 201 37009Email kai.fehske@ukw.deIntroduction/Background: Surfing, wind surfing and kite surfing enjoy a growing popularity with a large number of athletes worldwide. The aim of this study was to identify and compare the injury profiles and compare the injury profiles of these three extreme water sports.Materials and Methods: These data for this retrospective cohort study were collected through an online standardised questionnaire during the 2017– 18 season. The questionnaire included questions about anthropometry, skill level, injury diagnosis, injury mechanism, environmental conditions and training regimes.Results: The 626 athletes included reported 2584 injuries. On average, each athlete sustained 4.12 injuries during the season. The most frequent injury location was in the lower extremity, in particular the foot, with 49 (16.4%) injuries in surfing, 344 (18.3%) in wind surfing and 79 (19.7%) in kite surfing. Surfing demonstrated a particularly high rate of head injuries (n = 37; 12.4%). Other frequent injury types were skin lesions (up to 42.1%) and contusions (up to 40.5%). The most common injury across all surfing sports was skin lesions of the foot (wind surfing: 11.7%; kite surfing: 13.2%; surfing: 12.7%). In surfing, skin lesions of the head were frequently observed (n = 24; 8.0%). In surfing, a ‘too large wave’ (n = 18; 24.7%) was main cause of the injury, while in wind surfing (n = 189; 34.5%) and kite surfing (n = 65; 36.7%) ‘own incompetence’ led to the most injuries.Conclusion: This unique study compares injury epidemiology and mechanism in the three most popular surfing sports: wind surfing, kite surfing and surfing. Overall, injuries were sustained mainly in the lower extremity, while surfing also demonstrated a high rate of head injuries.Keywords: water sports, injury, training, ankle, foot, epidemiology

Volker Krutsch,1 Annabelle Clement,2 Tobias Heising,3 Leonard Achenbach,4 Christian Pfeifer,2 Johannes Weber,2 Volker Alt,2 Werner Krutsch2,5 1Department of Otorhinolaryngology, Paracelsus Medical University Nuremberg, Nuremberg, Germany; 2Department of Trauma Surgery, University Medical Centre Regensburg, Regensburg, Germany; 3Department of Internal Medicine, Marienhospital Osnabrueck, Osnabrueck, Germany; 4Department of Trauma Surgery, University Hospital Wuerzburg, Wuerzburg, Germany; 5SportDocsFranken, Nuremberg, GermanyCorrespondence: Werner KrutschDepartment of Trauma Surgery, University Medical Centre Regensburg, Franz-Josef-Strauß Allee 1, Regensburg 93053, GermanyTel +49 176 24225995Email werner.krutsch@ukr.dePurpose: Small-field soccer is a popular type of amateur sports worldwide. One type of small-field soccer growing in popularity is bubble-soccer, but injury risks and injury patterns are still unclear. This study investigates the factors influencing injuries in bubble-soccer for the first time.Materials and Methods: This prospective cohort study of an outdoor tournament investigated the injury incidence and injury patterns as well as the factors influencing injuries in bubble-soccer matches. Data were collected according to the statement on data collection and injury definition. Preparation and physical outcome were assessed for both sexes.Results: Of 145 players (104 men, 41 women), 58 players sustained 94 injuries during the tournament and 64% of injuries affected the lower extremities. The most common traumatic injuries were skin lesions (37.5%), acute pain (15.6%) and contusion (7.8%). More female players (3818.2/1000 h bubble-soccer) than male players (1474.4) were affected by injury, mostly to the knees or the head. Also, women significantly more often reported neck pain than men (p< 0.042); 29.0% of players felt uncomfortable wearing the bubble, and 21.4% reported neurological symptoms such as headache or dizziness after the match.Conclusion: Bubble-soccer shows a relatively high injury incidence. Women had a higher injury incidence and were more often affected by traumatic injuries to the head and neck including feeling of discomfort and headache or neck pain after the match. Adequate preparation seems to be essential for injury prevention, and players should recognise the high injury risk of bubble-soccer.Keywords: bubble soccer, injury, soccer, risk factor, prevention

Volker Krutsch,1 Stephan Grechenig,2 Oliver Loose,3 Leonard Achenbach,4 Johannes Zellner,2 Heiko Striegel,5 Volker Alt,2 Johannes Weber,2 Markus Braun,6 Stephan Gerling,7 Werner Krutsch2 1Department of Otorhinolaryngology, Head and Neck Surgery, Paracelsus Medical University, General Hospital Nuremberg, Nuremberg, Germany; 2Department of Trauma Surgery, University Medical Center Regensburg, Regensburg, Germany; 3Clinic of Pediatric Surgery, Olga Hospital, Clinic Stuttgart, Stuttgart, Germany; 4Department of Trauma Surgery, University Hospital Würzburg, Würzburg, Germany; 5Department of Sports Medicine, University Hospital Tuebingen, Tuebingen, Germany; 6Department of Sports Medicine, Clinic Westfalen, Dortmund, Germany; 7Department of Paediatric and Young Adult Medicine, Clinic St. Hedwig, Barmherzige Brüder Regensburg, Regensburg, GermanyCorrespondence: Werner KrutschDepartment of Trauma Surgery, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, Regensburg 93053, GermanyTel +49 941 9446805Email werner.krutsch@ukr.dePurpose: Injury data of professional soccer players obtained from media reports are frequently used in scientific research, but the accuracy of such data is still unclear.Patients and Methods: Injuries of professional soccer players of the German first and second league were documented by continuously screening media reports over one season (2015– 2016). After the season, the validity of media-reported injuries was anonymously analyzed by the team physicians of 8 different soccer clubs.Results: A total of 255 injuries of 240 players of 8 professional soccer teams had been published online, of which 146 were confirmed by the team doctors as correct, yielding a rate of 57.3% of confirmed media-reported injuries. In addition, 92 injuries without media registration were detected and added to the online statistics, resulting in 347 injuries and an overall weak validity of media-based data of 42.1%. Statistical analysis showed that the validity of media-reported injury data depended on both the individual soccer club and the body site affected by injury: publications on knee injuries (78.2%) had a higher validity than those on foot injuries (46.2%), and publications on severe injuries had a higher validity (joint dislocation: 100%; ligament rupture: 82.9%; fracture: 73.3%) than those on minor injuries. Publications on specific severe soccer injuries, such as anterior cruciate ligament (ACL) injuries, had a validity of 100%.Conclusion: Media-based injury data were only valid for a few severe injury types such as ACL injuries. In daily soccer routine and scientific research, media-based data should thus only be used in combination with specific criteria or verification processes.Keywords: professional football, injury, evidence, media-based, severe injury, ACL

Anaerobic microbial oxidation of Fe(II) was only recently discovered and very little is known about this metabolism. We recently demonstrated that several dissimilatory perchlorate-reducing bacteria could utilize Fe(II) as an electron donor under anaerobic conditions. Here we report on a more in-depth analysis of Fe(II) oxidation by one of these organisms, Dechlorosoma suillum. Similarly to most known nitrate-dependent Fe(II) oxidizers, D. suillum did not grow heterotrophically or lithoautotrophically by anaerobic Fe(II) oxidation. In the absence of a suitable organic carbon source, cells rapidly lysed even though nitrate-dependent Fe(II) oxidation was still occurring. The coupling of Fe(II) oxidation to a particular electron acceptor was dependent on the growth conditions of cells of D. suillum. As such, anaerobically grown cultures of D. suillum did not mediate Fe(II) oxidation with oxygen as the electron acceptor, while conversely, aerobically grown cultures did not mediate Fe(II) oxidation with nitrate as the electron acceptor. Anaerobic washed cell suspensions of D. suillum rapidly produced an orange/brown precipitate which X-ray diffraction analysis identified as amorphous ferric oxyhydroxide or ferrihydrite. This is similar to all other identified nitrate-dependent Fe(II) oxidizers but is in contrast to what is observed for growth cultures of D. suillum, which produced a mixed-valence Fe(II)–Fe(III) precipitate known as green rust. D. suillum rapidly oxidized the Fe(II) content of natural sediments. Although the form of ferrous iron in these sediments is unknown, it is probably a component of an insoluble mineral, as previous studies indicated that soluble Fe(II) is a relatively minor form of the total Fe(II) content of anoxic environments. The results of this study further enhance our knowledge of a poorly understood form of microbial metabolism and indicate that anaerobic Fe(II) oxidation by D. suillum is significantly different from previously described forms of nitrate-dependent microbial Fe(II) oxidation. [ABSTRACT FROM AUTHOR]

Green bean plants were grown in a greenhouse in soil removed from a soybean field in 1996 that had a high incidence of soybean sudden death syndrome (SDS). Over a period of 4 weeks, isolations were made from taproot tissue of green bean plants to recover Fusarium isolates. Ten isolates of Fusarium solani were recovered and used to inoculate soybean and green bean plants in the greenhouse. These 10 isolates caused typical SDS symptoms on the soybean plants and caused a root and crown rot on green bean plants. The green bean plants did not develop typical symptoms associated with soybean SDS but, rather, leaves on infected plants showed yellowing and necrosis. Molecular data indicated that these 10 isolates were identical to Fusarium solani f. sp. glycines that cause soybean sudden death syndrome. All isolates were re-isolated from greenhouse-inoculated soybean and green bean plants. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that at elevated temperatures in temperate lakes small cladoceran species are competitively superior to large species, which would cause a shift to smaller species in pelagic communities. As a measure of competitive ability, threshold food concentration, for growth (C0) were determined in a flow-through system at 16, 20, 24 and 28 deg.C. Four lake species were tested (in theorder of decreasing size): Daphnia pulicaria, D. galeata, D. ambiguaand Ceriodaphnia reticulata. C0 increased at temperaturesabove 20 deg.C, but the rank order of species was retained, i.e., the larger species had lower C0 at all temperatures. The twosmallest species showed a dramatic increase of C0 at 28 deg.C, hence their competitive ability was severely reduced. The hypothesis was rejected. In the temperature range tested, small cladoceranspecies were not competitively superior to large ones. The observed size shift from larger to smaller zooplankton in lakes with increasing temperature may be due to selective factors other than direct competition (e.g., predation, food quality). [ABSTRACT FROM AUTHOR]

Purpose: To identify the potential role of humeral retrotorsion (HRT) and range of motion (ROM) as a risk factor for shoulder overuse injury in elite youth handball players. The hypothesis was that increased HRT is associated with an increased risk of shoulder overuse injury., Methods: Over two seasons, 258 elite youth handball players (52% boys; age:14±0.8years) were included. Pre-season assessment included HRT and glenohumeral internal (IR) and external (ER) rotational ROM using ultrasound and a manual goniometer. Sports-specific adaptations between male and female athletes and the dominant and nondominant shoulder were calculated. In addition, players completed standardized questionnaires over the 2018-2019 or 2019-20 season and reported any shoulder overuse symptoms using the Western Ontario Shoulder Index questionnaire., Results: Comparing male and female players showed significantly decreased HRT and decreased internal ROM in the dominant side of male athletes (p≤0.027). No other difference was found. Significant side-to-side differences between the dominant and non-dominant shoulder were found for HRT, IR, and ER, regardless of sex (p<0.001). For total range of motion (TROM), only female athletes showed a significant increase in the dominant arm (p=0.032). The dominant side showed a significantly higher glenohumeral internal rotation deficit (GIRD) in male athletes than in female athletes (10°±17° vs. 5°±10°, p=0.011). Adaptations in HRT, ER gain, and TROM gain were not significant. Over the course of the two seasons, 20 athletes reported shoulder overuse injuries. Although GIRD was borderline non-significant (p=0.056), none of the parameters tested were significantly associated with shoulder overuse injuries., Conclusion: Despite significant side-to-side differences and sport-specific adaptations, individual pre-season screening of humeral retrotorsion and soft tissue adaptations does not identify elite youth handball athletes at increased risk of shoulder overuse injury., (Copyright © 2024. Published by Elsevier Inc.)

Background: To identify mechanisms and patterns of anterior cruciate ligament (ACL) injury in adult women's professional football by means of video match analysis., Methods: ACL match injuries sustained in Germany's first women's league during the 2016-2017 to 2022-2023 seasons were prospectively analysed by three expert raters using a standardised observation form. Epidemiological and injury data, as well as the medical history of ACL tears, were obtained from media reports and the statutory accident insurance for professional athletes., Results: Thirty-seven ACL injuries sustained in official football matches were included in the video analysis, of which 24 (65%) had associated knee injuries, mainly meniscus and collateral ligament injuries. According to the categorised contact mechanisms, 17 (46%) were non-contact injuries, 14 indirect contact injuries (38%) and six direct contact injuries (16%). Of the 17 non-contact injuries, seven (41%) occurred during the first 15 min of the match. Contact mechanisms did not differ between primary and secondary ACL injuries to the same or the contralateral side. Most injuries (80%) of field players occurred during horizontal movements such as sprinting (n=9, 26%), change-of-direction manoeuvres (n=7, 19%), stopping (n=5, 14%) and lunging (n=5, 14%). Four distinct repetitive patterns of ACL match injuries were identified: (1) non-contact 'pressing ACL injury' (n=9), (2) indirect contact 'parallel sprinting and tackling ACL injury' (n=7), (3) direct contact 'knee-to-knee ACL injury' (n=6) and (4) non-contact 'landing ACL injury' (n=4)., Conclusion: Most of the identified patterns of ACL injuries in women's professional football have great potential for prevention., Competing Interests: Competing interests: CK and HB are employed by the VBG., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To compare the standard Yo-Yo intermittent recovery (IR) test and an agility Yo-Yo IR test with a higher number of change-of-direction movements to cardiorespiratory match performance., Methods: The study included 11 professional male handball players (age 24.5 [4.6] y) of a German second-league team. The performance parameters of the players of the seasons 2016-17 to 2018-19 were analyzed. The Yo-Yo IR test was compared to a Yo-Yo IR test with multiple multidirectional changes of direction in response to visual stimuli, which was conducted on a SpeedCourt (Yo-Yo SC IR). Peak oxygen uptake (VO2peak) and maximum heart rate (HRmax) were measured. Between-methods differences of individual athletes were quantified with Bland-Altman plots., Results: HRmax was not statistically different during the Yo-Yo SC IR test compared to the Yo-Yo IR test (181 [10] vs 188 [8] beats·min-1; P = .16). Agreement between the 2 tests was moderate for HRmax and good for heart rates >180 beats·min-1. Mean average VO2peak was 51.7 (3.9) and 50.9 (2.8) mL·min-1·kg-1 for the Yo-Yo SC IR test and the Yo-Yo IR test (P = .693), respectively., Conclusions: A Yo-Yo test with multidirectional changes of direction in response to visual stimuli yielded good agreement with the frequently used linear running tests and can be used to assess players' VO2peak. The HRmax achieved during this test should be used with caution.

Objective: Two-stage exchange with an antibiotic-loaded polymethylmethacrylate (PMMA) spacer is standard treatment for chronic periprosthetic joint infection of the shoulder. We present a safe and simple technique for patient-specific spacer implants., Indication: (Chronic) periprosthetic joint infection of the shoulder., Relative Contraindications: Known allergy against components of PMMA bone cements. Inadequate compliance for two-stage exchange. Patient is unfit to undergo two-stage exchange., Surgical Technique: Hardware removal, histologic and microbiologic samples, and debridement. Preparation of targeted or calculated antibiotic-loaded PMMA. Tailoring of patient-specific spacer. Spacer implantation., Postoperative Management: Rehabilitation protocol. Antibiotic treatment. Reimplantation after successful eradication of infection., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

The aim was to investigate side-to-side and sex differences of anterior and inferior capsule thickness (ACT, ICT) between the throwing and non-throwing shoulder (TS, NTS) in youth elite handball players. 125 youth female and male elite handball players (14.1±0.7yo) were assessed for ACT and ICT by ultrasound . ACT measurement was performed from anterior (3 o'clock) in upright position and for ICT from inferior (6 o'clock) in supine position. Measurements of ICT in the TS of all athletes (1.4±0.2 mm) differed significantly but marginally to those in the NTS (1.3±0.2 mm) ( p = 0.001). Female (1.2±0.2 mm vs. 1.3±0.2 mm; p = 0.007) but not male youth players (1.4±0.2 mm vs. 1.4±0.2 mm, p = n.s.) demonstrated slight differences in ICT in the TS compared with the NTS. Although significant, the thickness in the TS compared to the NTS was within the measurement accuracy of the ultrasonic assessment. No difference in ACT was observed in the TS (1.4±0.3 mm) compared to the NTS (1.4±0.3 mm) for both sexes (n.s.).In conclusion, the anterior and inferior capsule thickness in youth elite handball athletes is not or only marginally different between throwing and non-throwing shoulders.

Introduction: To date, there is no valid single test or battery of tests for informing return-to-play (RTP) decisions following an acute shoulder injury. The purpose of this exploratory study is to evaluate a diagnostic test battery based on a Delphi consensus at the time of unrestricted return to team training after acute shoulder injury., Methods and Analysis: Data for this prospective multicentre cohort study are collected at two measurement time points: when the respective physician clears the patient for RTP (t1) and 12 months after RTP (t2). The study participants are 18-35 years old athletes participating at a professional level in the following team sports: handball, basketball, ice hockey, soccer, volleyball and American football. Maximum comparability will be ensured via uninjured matched pair teammates. To assess the subjective assessment of shoulder functioning and the athlete's readiness to RTP, patient-reported outcome measures (Western Ontario Shoulder Instability Index, Quick-Disabilities of the Arm, Shoulder and Hand, Psychological Readiness of Injured Athlete to Return to Sport and Shoulder Instability-Return to Sport after Injury) will be completed. After a medical check-up with a range of motion and anthropometric measurements as well as clinical tests, the participants will perform a structured warm-up protocol. The functional tests comprise handgrip strength, upper quarter Y-balance test, isometric strength, closed kinetic chain upper extremity stability test, wall hop test, functional throwing performance index and the unilateral seated shot put test and isokinetic tests., Ethics and Dissemination: The results of this study will be disseminated through peer-reviewed publications and scientific presentations at national and international conferences. Ethical approval was obtained through the Institutional Review Board of Martin-Luther-University Halle-Wittenberg (reference number: 2022-016)., Trial Registration Number: DRKS00028265., Competing Interests: Competing interests: HB works for the sponsor of the study as an advisor in the prevention field of sport (prevention department) and IB as an advisor in the field of insurance and benefits (rehabilitation department). Both supervise research projects in their departments and accompany the project participants until successful completion of the study. This is usually defined as successful implementation and transfer of the study results into practice., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To evaluate the functional outcome of partial reconstruction margin convergence in the treatment of massive, irreparable posterosuperior rotator cuff tear (RCT)., Methods: This retrospective, single-center study included all patients that were operated by means of a partial repair and infraspinatus shift for a massive, posterosuperior cuff tear between 2009 and 2016, either in arthroscopic or mini-open technique. Outcome measures included sex- and age-adapted Constant Score (saCS), Western Ontario Rotator Cuff (WORC) Index, Disabilities of Arm, Shoulder and Hand Scores (DASH), and relative effect per patient (REPP)., Results: Fifty-six shoulders in 54 patients (mean age: 66 ± 7 years) were evaluated at a mean follow-up of 40 ± 9 months. The mean tear size was Bateman 3.1 ± 0.7 and Patte 2.3 ± 0.4. All clinical scores showed improvement. The saCS improved from 64.1 ± 13.4 to 90.4 ± 13.7 (p < 0.0001), the DASH score from 51.8 ± 9.4 to 10.2 ± 13.4 (p < 0.0001) and the WORC index from 47.1% ± 8.6 to 87.9% ± 13.7 (p < 0.0001). The abduction strength of the affected side (1.7 ± 1.6 kg) was not restored to the same level as the contralateral side (5.4 ± 2.7 kg, p < 0.0001)., Conclusion: Partial cuff repair for posterosuperior, massive cuff tears yields good clinical outcome with a low rate of complications and high proportion of good and excellent responders., Level of Evidence: Level IV, therapeutic case series., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: ACL injuries are one of the most severe injuries in football, but medical consequences and performance outcomes after return to competition are only rarely investigated. Aim of this study was to analyse the time of return to competition (RTC) in German professional, semi-professional and amateur football. Also, this investigation highlights the rate of career ending and performance outcome after RTC in different playing levels by the measurement of playing level, performed matches and played minutes., Methods: Database of this investigation is the 'ACL registry in German Football' with prospectively collected injury data. Between 2014 and 2018, four seasons in professional (1st-3rd league), semi-professional (4th-6th league) and amateur leagues (7th league) were analysed regarding the return to competition period and performance parameters. Data were collected for three subsequent seasons after injury and compared with the pre-injury and injury season. Data collection was performed using standardized methods., Results: A total of 607 ACL injuries were registered during the 4-year period with a mean RTC time of 337.1 day (SD: 183). After primary ACL ruptures, the fastest RTC was found in professional football (247.3 days), while in semi-professional (333.5 d; p < 0.0001) and amateur football (376.2 d; p < 0.0001) a prolonged absence was detected. Re-ruptures occurred in 17.8% (n = 108) and showed similar trend with fastest RTC in professionals (289.9 days; p = 0.002). Within the first three seasons after injury, 92 players (36.7%) in semi-professional and 24 (20%) in professionals had to end their career. Keeping the level of play was only possible for 48 (47.5%) of professionals, while only 47 (29.6%) of semi-professionals and 43 (28.1%) of amateurs were able to. Only in professional football, no significant difference could be seen in the played minutes and games after 2 years compared to the pre-injury season., Conclusion: Lower playing levels and re-ruptures are the main factors for a prolonged return to competition after ACL rupture in German football. Significant reduction in playing level and a high rate of career endings were found for all levels of play. However, only professional players were able to regain their playing minutes and games 2 years after injury, while lower classed athletes did not reach the same amount within 3 years., Level of Evidence: Level III., (© 2022. The Author(s).)

Purpose: Anterior cruciate ligament (ACL) injuries are a common severe type of football injury. Injury prevention measures should be adapted to the respective type of sports and be based on sports-specific strategies. A football-specific ACL registry including prospective ACL injury data of both sexes and at different skill levels is lacking in the literature., Methods: In Germany, a prospective 'ACL registry for German Football' was implemented in the 2014-15 football season. Professional football leagues (1 st to 3 rd national league), semi-professional football leagues (4 th until 6 th leagues) and amateur football leagues (7 th league and below) were monitored regarding the incidence of ACL injuries, risk factors, general treatment and rehabilitation. After the registration of an injury, injured players were sent a standardised questionnaire., Results: Overall, 1,206 ACL ruptures were registered in the investigated population of more than 56,000 players, resulting in a prevalence of 2.1%. The highest prevalence was found in men's amateur football (2.7%) as well as in men's and women's professional football (2.1% each)., Conclusion: This football-specific ACL registry provides for the first-time longitudinal data about ACL injury patterns and treatment at all football levels. This report describes the considerations for data collection and presents first epidemiological results of 6 years of ACL injury registration.

A series of new mixed-substituted heteronuclear precursors with preformed Si-Ge bonds has been synthesized via a two-step synthesis protocol. The molecular sources combine convenient handling with sufficient thermal lability to provide access to group IV alloys with low carbon content. Differences in the molecule-material conversion by chemical vapor deposition (CVD) techniques are described and traced back to the molecular design. This study illustrates the possibility of tailoring the physical and chemical properties of single-source precursors for their application in the CVD of Si 1- x Ge x coatings. Moreover, partial crystallization of the Si 1- x Ge x has been achieved by Ga metal-supported CVD growth, which demonstrated the potential of the presented precursor class for the synthesis of crystalline group IV alloys.

Background and Objectives : The aim of the present study was to evaluate the efficacy of a multimodal pain therapy (MPM) regarding the objective parameter muscle strength of segment-dependent lower limb muscle groups before and after such a treatment. Materials and Methods : 52 patients with a history of low back pain and/or leg pain received standardized multimodal pain management. Strength of segment indicating lower limb muscles were assessed for each patient before and after ten days of treatment by handheld dynamometry. Results : Overall strength increased significantly from 23.6 kg ± 6.6 prior to treatment to 25.4 ± 7.3 after treatment, p ≤ 0.001. All muscle groups significantly increased in strength with exception of great toe extensors. Conclusions : Despite lower basic strength values at the beginning of treatment, all investigated muscle groups, except for the great toe extensors, showed a significant increase of overall strength after completion of the multimodal pain management concept. Increased overall strength could help with avoiding further need of medical care by supporting patients' autonomy in daily life activities, as well as maintaining working abilities. Thus, our study is the first to show a significant positive influence on lower limb strength in patients with low back pain after a conservative MPM program.

Purpose: Anterior cruciate ligament (ACL) injuries are a common severe type of football injury at all levels of play. A football-specific ACL registry providing both prospective ACL injury data according to the skill level and risk factors for ACL injury is lacking in the literature., Methods: This study is based on the prospective 'ACL registry in German Football' implemented in the 2014-15 season. Professional (1st-3rd league), semi-professional (4th-6th league) and amateur leagues (7th league) were analysed regarding the incidence and risk factors for ACL injuries. Injuries were registered according to the direct reports of the injured players to the study office and double-checked via media analysis. After injury registration, the players received a standardised questionnaire. Data were analysed from the 2014-15 to the 2018-19 football season., Results: Overall, 958 ACL injuries were registered during the 5-year study period. The incidence of ACL injuries was highest in amateur football (0.074/1000 h football exposure) compared to professional (0.058/1000 h; p < 0.0001) and semi-professional football (0.043/1000 h; p < 0.0001). At all skill levels, match incidence (professional: 0.343; semi-professional: 0.249; amateur: 0.319) was significantly higher than training incidence (professional: 0.015; semi-professional: 0.004; amateur: 0.005). Major risk factors were previous ACL injury (mean: 23.3%), other knee injuries (mean: 19.3%) and move to a higher league (mean: 24.2%)., Conclusion: This sports-specific ACL registry provides detailed information on the incidence and risk factors for ACL injuries in football over five years. Risk factors are skill level, match exposure, move to a higher league and previous knee injury. These factors offer potential starting points for screening at-risk players and applying targeted prevention., Level of Evidence: II., (© 2021. The Author(s).)

Objectives: Handball is associated with a high risk of overuse shoulder injury. This study investigated if an injury prevention programme effectively reduces overuse injury to the throwing shoulder of handball athletes., Methods: 61 men's and women's handball teams (u-19 and senior athletes) were cluster-randomised into an intervention and a control group in the 2019-2020 season. Players of the intervention group regularly carried out an injury prevention programme. Both groups documented overuse shoulder injuries via an online questionnaire every second week. The primary endpoint was the prevalence of overuse injury to the throwing shoulder. Secondary endpoints were the influence of compliance on the primary endpoint and intensity of overuse shoulder symptoms measured by a shortened, handball-specific Western Ontario Shoulder Index (WOSI)., Results: 31 teams (295 players) in the intervention group and 30 teams (284 players) in the control group were included for analyses. The overall questionnaire response rate was 61%. The average prevalence of overuse shoulder injury did not significantly differ between the intervention group (n=109, 38.4% (95% CI 32.9% to 44.2%)) and the control group (n=106, 35.9% (95% CI 30.7% to 41.6%), p=0.542). Compliance with the intervention programme did not significantly affect overuse shoulder injury (p=0.893). Using generalised estimating equations for WOSI, the estimated mean for the intervention group was 44.6 points (95% CI 42.0 to 47.1) and 47.6 points for the control group (95% CI 44.9 to 50.3, p=0.111)., Conclusions: A multicomponent exercise programme using rubber bands and stretching did not significantly reduce the prevalence or symptoms of overuse throwing shoulder injury in handball athletes of both sexes. Randomised controlled study; level of evidence I., Trial Registration Number: ISRCTN99023492., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)