Prevention of severe knee injuries in men's elite football by implementing specific training modules.

PURPOSE: Injury prevention of knee injuries by means of training and warm-up exercises has been investigated in several studies in amateur football. However, the number of investigations in elite football is limited despite the currently higher injury incidence of severe knee injuries. Therefore, the purpose of this study was to investigate whether specifically adapted preventive training modules may reduce severe knee injuries in elite football. METHODS: In a prospective controlled cohort study of elite football players in Germany, an injury prevention programme with 5 modules was implemented in the season of 2015-2016. The training modules were specifically adapted to this skill level and based on scientific evidence, team coach preferences, and the specific environment of this playing level. Of the 62 teams taking part in this study, 26 used the new trainings modules and 36 continued their standard programme as a control group. Success of the programme was documented by means of an injury report over one season. The primary outcome was reduction in severe knee injuries. RESULTS: A pre-seasonal investigation had identified five modules to be implemented in the training routine. Postural stability, mobilisation of lower extremity joints, leg and trunk stabilisation, jumping, and landing exercises as well as agility movements were incorporated into the programme to prevent severe knee injuries in elite football. Over the season, the study group (529 players) with the adapted training modules had sustained 52 severe knee injuries (incidence: 0.38 per 1000 h football exposure; prevalence: 9.8%) compared to 108 severe knee injuries in the control group (601 players) using the standard programme (incidence: 0.68 per 1000 h football exposure; prevalence: 18.0%; p < 0.05). The overall injury incidence for any other type of injury was comparable between the two groups (3.3 vs. 3.4 in h 1000 football, n.s.). CONCLUSION: Appropriate preventive training modules reduce severe knee injuries in elite football significantly. The key for the sustainability of preventive training measures are programmes specifically adapted to the demands of the playing level and to the preferences of the coaches LEVEL OF EVIDENCE: II.

Tenomodulin regulates matrix remodeling of mouse tendon stem/progenitor cells in an ex vivo collagen I gel model.

Tenomodulin (Tnmd) is predominantly expressed in tendon and ligament tissues. Loss of Tnmd in mice leads to a profound phenotype in vitro, characterized by reduced self-renewal but increased senescence of mouse tendon stem/progenitor cells (mTSPCs), as well as in vivo, by significantly impaired early tendon healing. Interestingly, injuried Achilles tendons from Tnmd-deficient mice showed inferior tendon repair, which was characterized by less contracted fibrovascular scars with disorganized matrix composition in comparison to wild type (WT) mice at day 8 after injury. To better understand Tnmd role in tendon repair, here we implemented an ex vivo three-dimensional (3D) collagen gel model and investigated whether Tnmd knockout affects the collagen contraction of mTSPCs. TSPCs were isolated from WT and Tnmd knockout (KO) tendons at 6, 9, 12, and 18 months of age. Adhesion assay demonstrated that loss of Tnmd in mTSPCs resulted in reduced adhesion to collagen type I. Quantitative time-dependent analysis revealed that Tnmd-deficient mTSPCs of all ages have significantly reduced capacity to contract collagen matrix in comparison to WT cells. Furthermore, 18 months old mTSPCs of both genotypes showed lower collagen contractility than cells obtained from 6, 9, and 12 months old animals, demonstrating an overall effect of organismal aging on matrix remodeling. Nevertheless, both cell types had a similar survival rate for the 5 days of cultivation within the gels. Lastly, quantitative PCR for 48 different genes revealed that the knockout of Tnmd majorly affected the gene expression profile of mTSPCs, as several transcription factors, tendon matrix, collagen cross-linking, and lineage maker genes were down-regulated. Taken together, our results clearly demonstrated that loss of Tnmd in mTSPCs led to profoundly altered gene expression profile, insufficient adhesion to collagen type I, and impaired ability to contract the extracellular matrix.

Risk factor analysis for delayed union after subtrochanteric femur fracture: quality of reduction and valgization are the key to success.

BACKGROUND: Subtrochanteric femur fractures (SFF) are uncommon, but have a high complication rate concerning non-union and mechanical complications. There is ongoing discussion about risk factors for delayed fracture healing after SFF. The purpose of this study was to evaluate potential risk factors for delayed fracture healing after SFF. METHODS: This retrospective radio-morphometric case control study compares 61 patients after SFF in two groups (uncomplicated healing within 6 months postoperatively vs. delayed union) concerning radiographical properties. The patients were analyzed concerning the following parameter: Quality of the reduction according to Baumgaertner, CCD-angle, Tip-Apex Distance, leg-length shortening and fracture healing according to the RUSH Score. RESULTS: The mean RUSH-Score at 6 months postoperatively was 21.32(±4.57). At that point of time, only 29/61 fractures were radiographically fully consolidated (timely fracture healing) and 32 patients were rated as delayed union. The total revision rate was 9/61 (14.7%), whereof four patients required revision for symptomatic non-union of the SFF. The results of the radio-morphometric measurement showed a significant difference between both groups concerning the degree of reduction measured according to Baumgaertner (p = 0.022). The postoperative ipsilateral CCD-angle was different between the two groups (p = 0.019). After 12 months postoperatively, 48/61 (78.6%) of fractures were rated healed without any further intervention. CONCLUSIONS: Delayed union after SFF occurs frequently. In our patient population, the quality of reduction and the postoperative CCD-angle were the key factors to avoid delayed union. LEVEL OF EVIDENCE: Level III, Therapeutic study. TRIAL REGISTRATION: Clinical Trial Registry University of Regensburg Z-2018-1074-1. Registered 04. Aug 2018. https://studienanmeldung.zks-regensburg.de.

Contact times of change-of-direction manoeuvres are influenced by age and the type of sports: a novel protocol using the SpeedCourt® system.

PURPOSE: Side-to-side asymmetry in side-cutting manoeuvres is a known risk factor for severe knee injury. Potential leg asymmetry during ground contact times of different change-of-direction manoeuvres was evaluated in athletes by means of the recently developed SpeedCourt® system. The hypotheses were that ground contact times and the limb symmetry index are affected by age and the type of sports. METHODS: One-hundred and sixty-five athletes (149 men, 16 women, age 16.5 ± 5.1) of popular team sports such as football, team handball and baseball were assessed by means of three different tests [side-hop, lateral change-of-direction (COD) and diagonal COD] using the SpeedCourt® system. Analysis included the factors age, sex, type of sports, ground contact time, leg symmetry index and limb dominance. RESULTS: During lateral but not diagonal COD tests, football players had shorter contact times than players of team handball (p = 0.026) and baseball (p = 0.015) of the same age group. The side-hop tests yielded differences in the leg symmetry index between players < 16 years and players > 16 years (p < 0.01). Mean ground contact time differed in each of the side-hop, lateral COD and diagonal COD tests (143.5 ± 20.0 vs. 256.2 ± 66.1 vs. 320.4 ± 55.0). Contact times and test durations of side-hop, lateral COD and diagonal COD tests were shorter for older players (p < 0.01). CONCLUSIONS: Ground contact times of side-hop and change-of-direction manoeuvres are influenced by age, the type of sports and limb dominance. Such information is fundamental for future sports medicine research and needs to be considered in pre-season screening or when used as a criterion for return-to-competition of players with previous severe knee injury. Assessment of change-of-direction manoeuvres should be included in future return-to-competition test batteries. LEVEL OF EVIDENCE: III.

Injury incidence in semi-professional football claims for increased need of injury prevention in elite junior football.

PURPOSE: Injuries are a common occurrence in football. Sufficient epidemiological data are available in professional football but not in salaried semi-professional football. This study investigates the injury incidence at different levels of semi-professional football with focus on junior football. METHODS: The data were based on injury reports provided by players and medical staff over the 2015-2016 season, which corresponded to the consensus statement for data samples in football. This study investigated the injury incidence and prevalence of five skill levels of semi-professional football (the fourth to the seventh league and elite junior football). RESULTS: 1130 players had sustained 2630 injuries over the 2015-2016 season. The overall injury incidence was 9.7 per 1000 h football exposure; prevalence with at least one injury was 79%. The highest overall injury incidence in elite junior football was 10.4 in 1000 h football exposure. The fifth league had the lowest incidence with 9.0 in 1000 h football (p < 0.05). Traumatic injuries most often occurred in the fourth league (3.9 in 1000 h football). The body areas most affected by traumatic injury were knees, ankles and thighs. Elite junior players had a significantly higher incidence of overuse complaints (7.4 in 1000 h football) than the fourth league (5.4, p = 0.005). The body areas most affected by overuse complaints were the lower back, thigh and groin. No differences were found between the different positions on field. CONCLUSIONS: Salaried semi-professional football involves a high overall injury incidence. The highest incidence, particularly of overuse injuries, was seen in elite junior football. These findings should be incorporated in specific injury prevention training or screenings beginning in junior football. Level of evidence II.

Patient-related quality of life after pelvic ring fractures in elderly.

PURPOSE: Pelvic ring fractures, occurring in elderly patients are a challenging problem. Little known is about the patient-related outcome after these injuries. The primary objective of this study is to evaluate the quality of life after pelvic ring injuries in patients aged over 60 years. METHODS: Patients (≥ 60 years) with pelvic ring fractures treated in our trauma department between 2004 and 2014 were included. Next to patient data, injury-related details as well as treatment details were assessed. After a follow-up of at least two years, the survival rate and the patient-related outcome were evaluated using the SF-36 and the EQ-5D score. RESULTS: One hundred ninety-six patients (138 women; 58 men; mean age 75.3 ± 7.8 years) were identified. Ninety-six patients were treated operatively, 100 patients conservatively. The overall complication rate was significantly lower for conservatively compared to operatively treated patients (conservatively 18% vs. operatively 33%; p = 0.014). The total mortality rate over 2 years is 29% with no significant difference of the two-year survival rate (2-year survival rate: operatively 77% vs. non-operatively 65%; p = 0.126). Fifty-five patients completed the SF-36 and EQ-5D score after a mean follow-up of 4.2 ± 2.9 years. The mean physical component score of the SF-36 is 33.6 ± 8.3, and the mean mental component score is 45.3 ± 8.4. The mean EQ-5D VAS reached 62.5 ± 27.9. CONCLUSION: Elderly patients with pelvic ring fractures show a high mortality rate and a limited patient-related outcome. While the complication rate of conservatively treated patients is lower compared to operated patients, the two year survival rate is steady.

Clinical application of a minimally invasive cement-augmentable Schanz screw rod system to treat pelvic ring fractures.

PURPOSE: The purpose of this study is to analyze the results using the USS fracture MIS system (DePuy Synthes) to treat instable pelvic ring fractures. As its outstanding feature, it is the only Schanz screw and rod system at present that combines angular stability, perforation/fenestration of the screws for cement-augmentation, a variable screw length, and a large screw diameter. MATERIALS AND METHODS: Retrospective investigation of 134 pelvic ring fractures treated in 2012-2013. Twenty-five patients obtained the abovementioned implant. Besides baseline characteristics of the included patients and the surgical procedure, a clinical/radiological follow-up of six months was analyzed. RESULTS: Dividing the collective into two groups, I high-energy trauma and II fragility fracture of the pelvis, the following results were recorded: group I: ten patients, six male, age 48.4 ± 19.7 years. Mean ISS 41 ± 22.5, fracture classification: AO/OTA type 61 B1/C1/C3 = 1/5/4. Operative treatment: three transiliac internal fixator, seven iliolumbar fixation, one implant was cement-augmented. Group II: 15 patients, 14 female, age 77.5 ± 10.1 years. Fracture classification according to Rommens: FFPII/III/IV = 6/1/8. Operative treatment: eight transiliac internal fixator, seven iliolumbar fixation, 14 implants were cement-augmented. Overall surgical side complications: 16%. Radiological examination: correct positioning of all ilium screws. Follow-up after six month (16 patients): all showed fracture consolidation. One ilium screw was broken close to the connecting clamp. CONCLUSION: The investigated Schanz screw rod system is a suitable implant to broaden the established procedures to stabilize dorsal pelvic ring fractures. TRIAL REGISTRATION: The study is registered at the Clinical Trial Registry University of Regensburg (Number Z-2017-0878-3).

Bone Marrow Aspirate Concentrate for the Treatment of Avascular Meniscus Tears in a One-Step Procedure-Evaluation of an In Vivo Model.

Avascular meniscus tears show poor intrinsic regenerative potential. Thus, lesions within this area predispose the patient to developing knee osteoarthritis. Current research focuses on regenerative approaches using growth factors or mesenchymal stem cells (MSCs) to enhance healing capacity within the avascular meniscus zone. The use of MSCs especially as progenitor cells and a source of growth factors has shown promising results. However, present studies use bone-marrow-derived BMSCs in a two-step procedure, which is limiting the transfer in clinical praxis. So, the aim of this study was to evaluate a one-step procedure using bone marrow aspirate concentrate (BMAC), containing BMSCs, for inducing the regeneration of avascular meniscus lesions. Longitudinal meniscus tears of 4 mm in size of the lateral New Zealand White rabbit meniscus were treated with clotted autologous PRP (platelet-rich plasma) or BMAC and a meniscus suture or a meniscus suture alone. Menisci were harvested at 6 and 12 weeks after initial surgery. Macroscopical and histological evaluation was performed according to an established Meniscus Scoring System. BMAC significantly enhanced regeneration of the meniscus lesions in a time-dependent manner and in comparison to the PRP and control groups, where no healing could be observed. Treatment of avascular meniscus lesions with BMAC and meniscus suturing seems to be a promising approach to promote meniscus regeneration in the avascular zone using a one-step procedure.

Long-term outcome after surgical treatment of intra-articular tibial plateau fractures in skiers.

INTRODUCTION: Tibial plateau fractures occur frequently during downhill skiing. There is a lack of information about the outcome and development of posttraumatic osteoarthritis after internal fixation of such fractures at long-term follow-up in skiers. MATERIALS AND METHODS: A population of 83 skiers was followed up in a case series after internal fixation of intra-articular tibial plateau fractures AO-OTA 41 B1-B3 and C1-C3. Functional outcomes Visual Analog Scale, Tegner Activity Scale, Modified Lysholm Score, Hospital for Special Surgery (HSS) Knee Score and X-ray images of the affected knees (preoperative, postoperative and at time of follow-up) were obtained. Radiological evaluation focused on severity of osteoarthritis according to the Kellgren and Lawrence score of the lateral, medial and retropatellar knee compartments separately. Subgroup analyses for fracture type and age were performed separately. RESULTS: Patients age was 49.8 ± 12.9 years (range 19-74 years) at the time of surgery, with a mean follow-up period of 10.3 ± 1.9 years (range 6-14 years). All tibial plateau fractures affected the lateral compartment, while the medial compartment was affected in addition as part of bicondylar fractures in two cases. Both the Tegener Activity Scale and Lysholm Score decreased significantly during the follow-up period and their median values dropped from 6 (range 3-7) to 5 (range 2-7) and from 100 (range 90-100) to 95 (range 58-100), respectively (both p < .01). The median clinical knee function at the time of follow-up revealed an HSS Knee Score of 96.5 points (range 74-100). Among the whole patient population, the radiological evaluation at follow-up revealed a significantly higher grade of osteoarthritis in all compartments of the knee joint compared to the time of the operation (p < .01). The grade of osteoarthritis in the lateral compartment was significantly higher than that in the medial and retropatellar compartments (p < .01). CONCLUSIONS: In addition to physiologic aging, progression of radiologic signs of osteoarthritis following internal fixation of intra-articular tibial plateau fractures in an athletic population of skiers is most severe in the lateral knee compartment corresponding to fracture location. However, the long-term functional outcomes seem to be very satisfactory.

Social capital in a regional inter-hospital network among trauma centers (trauma network): results of a qualitative study in Germany.

BACKGROUND: As inter-hospital alliances have become increasingly popular in the healthcare sector, it is important to understand the challenges and benefits that the interaction between representatives of different hospitals entail. A prominent example of inter-hospital alliances are certified 'trauma networks', which consist of 5-30 trauma departments in a given region. Trauma networks are designed to improve trauma care by providing a coordinated response to injury, and have developed across the USA and multiple European countries since the 1960s. Their members need to interact regularly, e.g. develop joint protocols for patient transfer, or discuss patient safety. Social capital is a concept focusing on the development and benefits of relations and interactions within a network. The aim of our study was to explore how social capital is generated and used in a regional German trauma network. METHODS: In this qualitative study, we performed semi-standardized face-to-face interviews with 23 senior trauma surgeons (2013-14). They were the official representatives of 23 out of 26 member hospitals of the Trauma Network Eastern Bavaria. The interviews covered the structure and functioning of the network, climate and reciprocity within the network, the development of social identity, and different resources and benefits derived from the network (e.g. facilitation of interactions, advocacy, work satisfaction). Transcripts were coded using thematic content analysis. RESULTS: According to the interviews, the studied trauma network became a group of surgeons with substantial bonding social capital. The surgeons perceived that the network's culture of interaction was flat, and they identified with the network due to a climate of mutual respect. They felt that the inclusive leadership helped establish a norm of reciprocity. Among the interviewed surgeons, the gain of technical information was seen as less important than the exchange of information on political aspects. The perceived resources derived from this social capital were smoother interactions, a higher medical credibility, and joint advocacy securing certain privileges. CONCLUSION: Apart from addressing quality of care, a trauma network may, by way of strengthening social capital among its members, serve as a valuable resource for the participating surgeons. Some member hospitals could exploit the social capital for strategic benefits.

3D analysis of Osteosyntheses material using semi-automated CT segmentation: a case series of a 4 corner fusion plate.

BACKROUND: Scaphoidectomy and midcarpal fusion can be performed using traditional fixation methods like K-wires, staples, screws or different dorsal (non)locking arthrodesis systems. The aim of this study is to test the Aptus four corner locking plate and to compare the clinical findings to the data revealed by CT scans and semi-automated segmentation. METHODS: This is a retrospective review of eleven patients suffering from scapholunate advanced collapse (SLAC) or scaphoid non-union advanced collapse (SNAC) wrist, who received a four corner fusion between August 2011 and July 2014. The clinical evaluation consisted of measuring the range of motion (ROM), strength and pain on a visual analogue scale (VAS). Additionally, the Disabilities of the Arm, Shoulder and Hand (QuickDASH) and the Mayo Wrist Score were assessed. A computerized tomography (CT) of the wrist was obtained six weeks postoperatively. After semi-automated segmentation of the CT scans, the models were post processed and surveyed. RESULTS: During the six-month follow-up mean range of motion (ROM) of the operated wrist was 60°, consisting of 30° extension and 30° flexion. While pain levels decreased significantly, 54% of grip strength and 89% of pinch strength were preserved compared to the contralateral healthy wrist. Union could be detected in all CT scans of the wrist. While X-ray pictures obtained postoperatively revealed no pathology, two user related technical complications were found through the 3D analysis, which correlated to the clinical outcome. CONCLUSION: Due to semi-automated segmentation and 3D analysis it has been proved that the plate design can keep up to the manufacturers' promises. Over all, this case series confirmed that the plate can compete with the coexisting techniques concerning clinical outcome, union and complication rate.

Beach handball is safer than indoor team handball: injury rates during the 2017 European Beach Handball Championships.

PURPOSE: Beach handball is a relatively new type of sports, which was derived from team handball. Medical issues such as frequency and severity of injury are yet unknown. The purpose of this study was to investigate the injury pattern and injury rates of this new type of sports. METHODS: This study investigated the injury incidence of 30 national teams (10 senior and 20 u-17 teams, 16 men's and 14 women's teams) participating in the 2017 European Beach Handball Championships. Reports on injuries sustained during the senior and u-17 youth tournaments were provided by the medical staff of each team. Injury incidence was differentiated between age and sex, and between the five field positions (goalkeeper, wing, central defender, pivot, and specialist). RESULTS: During the tournaments, 87 injuries were recorded yielding an overall injury incidence of 286.1 per 1000 match hours. Time-loss due to injury was 49.3 per 1000 match hours. Senior players had a higher overall injury incidence with 395.3 injuries than u-17 players with 205.7 injuries per 1000 h match hours (p < 0.01). Comparison of the injury incidence between the two sexes showed 330.23 injuries per 1000 h handball exposure for male players and 234.9 injuries for female players (n.s.). The most frequent injury type was sprains (21 injuries, 24.1%) followed by contusions (19 injuries, 21.8%) and skin abrasions with (15 injuries, 17.2%). Central defenders and specialists had the highest injury incidence. Thighs, ankles, as well as foot and toes (altogether 12 injuries, all 13.8%) were the three most frequently injured anatomic sites. CONCLUSIONS: Beach handball seems to have a lower incidence of time-loss injuries than that reported for indoor team handball. This study is an important basis for developing injury prevention strategies in this sports that should focus on thighs, ankles, feet and toes. Further research into this new type of sports is essential to identify risk factors and to develop adequate injury prevention measures. LEVEL OF EVIDENCE: II.

Injury mechanism of midfacial fractures in football causes in over 40% typical neurological symptoms of minor brain injuries.

PURPOSE: The injury mechanisms of midfacial fractures may be typical causes of concussion, but hardly any scientific data on midfacial injuries sustained in football are available. Head and brain trauma represent frequent injuries in athletes of different sports that require appropriate treatment by sports and trauma physicians. This study investigated the management of midfacial fractures in football and the association of such fractures with concomitant brain injury. METHODS: In a prospective cohort study lasting 24 months (2012 to 2013), midfacial injuries of football players were analysed with regard to the injury mechanisms, first aid procedures on the field, treatment and return-to-play. To analyse concomitant and potentially overlooked minor brain injuries due to the trauma, we retrospectively investigated the neurological symptoms of the study population. RESULTS: The study included 132 football players (37 semi-professionals and 95 amateurs) with midfacial fractures. The main injury mechanisms were head-to-head and head-to-elbow trauma. The mean period of return-to-play after trauma was 33.5 days, which was significantly shortened if a protective face mask was worn (mean 10.4 days earlier, p = 0.0006). Semi-professional football players returned to play earlier (p = 0.009) and more often used protective face masks (p = 0.001). 55 players (41.6%) had neurological symptoms immediately after trauma as a possible sign of concomitant minor brain injury. 5 of 132 players with concussion had been hospitalised for 24 h, but no persistent neurological symptoms were detected. CONCLUSION: In football, midfacial fractures represent moderate-to-severe injuries with time away from sports of more than 4 weeks. Over 40% of athletes with a midfacial fracture showed concomitant neurological symptoms as a sign of minor brain injury. Therefore, sports physicians and other staff supervising athletes in daily practice should be aware of the presence of neurological symptoms. LEVEL OF EVIDENCE: Level III.

Neuromuscular exercises prevent severe knee injury in adolescent team handball players.

PURPOSE: Team handball is associated with a high risk of severe knee injury that needs to be reduced, particularly at the youth level. The purpose of this study was to show how an injury-prevention programme effectively reduces severe knee injury in adolescent team handball players. METHODS: Of 23 adolescent handball teams of both sexes, 13 were randomly allocated into the intervention group (168 players) and 10 into the control group (111 players). Players of the intervention group regularly participated in an injury-prevention programme for one season. Handball exposure and sustained injuries were documented for both groups on a monthly basis. The primary outcome parameter of the injury-prevention programme was the incidence of severe knee injury. RESULTS: Of the 279 included players, 68 (24%) sustained 82 injuries yielding an overall incidence of 1.85 injuries per 1000 h handball exposure (intervention group: 50 injuries/incidence: 1.90/1000 h; control group: 32 injuries/incidence: 1.78/1000 h). Knee injury was the second most frequent injury in adolescent team handball. The primary outcome parameter, severe knee injury occurred significantly more often in the control group [mean age (SD) 15.1 (1.0), injury incidence 0.33/1000 h] than in the intervention group [mean age (SD) 14.9 (0.9), injury incidence 0.04/1000 h]. The odds ratio was 0.11 (95% CI 0.01-0.90), p = 0.019. Other injuries to the lower extremities showed no significant difference between the two groups. CONCLUSIONS: Frequent neuromuscular exercises prevent severe knee injury in adolescent team handball players and should thus be included in the practical routine as well as in the education of team coaches.

Increased injury rates after the restructure of Germany's national second league of team handball.

PURPOSE: Scientific injury data in men's professional team handball injuries are rare and even less scientific information exists on injury prevention. In 2011, Germany's national second team handball league was restructured by merging the existing two regional leagues into one league. This study evaluates the injury patterns in professional team handball and compares the injury rates between the first and second league before and after the restructure. METHODS: All players of Germany's national first and second men's team handball leagues have mandatory trauma insurance with the same insurance company. This retrospective cohort study analysed the injury data of three consecutive seasons 2010-2013 using standardized injury definitions. RESULTS: 1194 professional team handball players were included in this study. The majority of severe injuries affected the lower extremities, shoulders, and hands. The average injury incidence significantly differed between the first (4.9 injuries per 1000 h) and the second league (3.9 per 1000 h, p < 0.01). The injury incidence in the restructured second league had increased from 3.7 to 4.1 per 1000 h (p < 0.01) and prevalence from 67.1 to 79.3% (p < 0.001), thus almost to the same levels of the first league. The second league showed more time-loss injuries at all severity levels. CONCLUSION: This study yielded a high injury incidence after the restructure of the national second team handball league and presents details on prevalence, incidence, and patterns of injury in professional men's team handball. This study is an important basis for developing injury prevention strategies that should focus on the shoulders, hands, and lower extremities and on reducing the number of matches and travel burden. LEVEL OF EVIDENCE: III.

Reduced joint-awareness in bicruciate-retaining total knee arthroplasty compared to cruciate-sacrificing total knee arthroplasty.

PURPOSE: There is rising impact of patient-reported outcome (PRO) measurement in joint arthroplasty over the past years. Bicruciate-retaining implants have shown more physiologic knee kinematics and provide superior proprioceptive capacities. The aim of this study was to evaluate if the functional properties of this new implant design lead to improved PRO results after total knee arthroplasty (TKA). METHODS: This prospective, controlled trial compares PRO of bicruciate-retaining total knee arthroplasty (BCR-TKA) to unicondylar knee arthroplasty (UKA) and standard posterior-stabilized total knee arthroplasty (PS-TKA). We evaluated 102 patients (34 patients in each group) 18 months postoperatively after knee arthroplasty. Primary outcome measure was the Forgotten Joint Score (FJS). RESULTS: The BCR-group showed the same level of joint awareness as the UKA-group (p = 0.999). The second control group of PS-TKA patients had a lower mean score value in the FJS compared to the BCR-group (p = 0.035) and UKA-group (p = 0.031). There was no correlation of age, gender, body mass index (BMI) and the FJS. No relevant floor- or ceiling effects occurred. CONCLUSIONS: This study found reduced joint awareness for BCR-TKA compared to a standard total knee arthroplasty. The score values of the BCR-group were equal to the UKA-group. Further prospective, randomized studies to investigate long-term survivorship of bicruciate-retaining implants are needed. LEVEL OF EVIDENCE: Level II.

Injury prevention and return to play strategies in elite football: no consent between players and team coaches.

INTRODUCTION: Injuries are a common problem in football. To improve prevention strategies, the players' (p) and coaches' (c) views need to be disclosed as they have a strong impact on return to play decisions. The aim of this study is to reveal current opinions with regard to injury prevention and return to play strategies to introduce new strategies in elite football. MATERIALS AND METHODS: In a retrospective data analysis of elite salaried football players (n = 486) and team coaches (n = 88), a detailed investigation by means of a standardized questionnaire was carried out. In a preseason period of the 2015/16 season and as part of a large interventional research project in elite salaried German football, a request about players' and team coaches' knowledge and opinions was performed. Topics such as injury prevention, return to play after injuries, the importance of screening tests, general problems of injuries in football, or the decision-making in terms of prevention and return to play in elite football were investigated. RESULTS: The study revealed a high interest in injury prevention and screening tests among players and coaches (p 82.5%; c 99.1%). The participants of the study reported warm-up exercises (p 76.4%; c 74.7%), regeneration training (p 54.1%; c 56.3%), and core stability (p 53.8; c 70.1%) as the most important prevention methods, but the additional investigation of the teams' current daily training routine showed that the transfer is incomplete. Coaches are more familiar with scientific published warm-up programs like FIFA 11 + than players (42.5 vs. 12.6; p < 0.001). Knee injuries (p 90.7%; c 93.1%) and ACL injuries in particular were reported as the most severe and common problem in elite football. Players and coaches expressed different attitudes concerning return to play decisions. While players want to decide themselves (81.4%), team coaches consult medical advice ahead of the decision of return to play after injuries (83.5%; p < 0.001). Decisions against the doctor's recommendation are often made by both groups (p 64.4% vs. c 87.1%; p < 0.001). CONCLUSION: The basic knowledge of prevention and injuries is sufficient in elite football, but the transfer from theoretical knowledge to practical routine is suboptimal. The study also shows possibilities to improve the prevention process and communication between players, coaches, doctors, and physiotherapists, while there is no consent between players and coaches regarding return to play decision.

Correction to: Intra-ligamentary autologous conditioned plasma and healing response to treat partial ACL ruptures.

With regards to Berardo Di Matteo, second author. The author's name is incorrectly listed on Pub-Med. The first and last name have been mixed up.

Intra-ligamentary autologous conditioned plasma and healing response to treat partial ACL ruptures.

INTRODUCTION: Conservative treatment of partial ACL ruptures is associated with a high failure rate, and often patients undergo ACL reconstruction. ACL preservation by trephination of the ACL origin and application of Autologous Conditioned Plasma (ACP) seems to be an intriguing new treatment option to favour ACL tissue healing and avoid traditional reconstruction. The aim of this study was to describe the mid-term outcomes of this new ACL preserving technique. MATERIALS AND METHODS: Twenty-four patients (mean age 41.8 years) affected by partial rupture of one or both ACL bundles were included in the present trial. The partial ACL tears were arthroscopically assessed and classified according to a new five step grading system. All patients were treated by trephination of the femoral ACL stump and intra-ligamentary application of ACP. The postoperative outcome was evaluated by both subjective scores and stability testing up to a mean of 25.1 months' follow-up. Adverse events and failure rate were also documented. RESULTS: Clinical outcome was good to excellent with IKDC subjective 82.7 (SD 11.8), Lysholm 87.6 (SD 8.1), Tegner 5.3 (SD 2.1), Cincinnati 88.7 (SD 14.8). The failure rate (i.e. persisting knee instability assessed clinically or by rolimeter) was 12.5%. At objective measurements, knee joints showed a firm endpoint in Lachman test, negative pivot shift phenomenon and a significant reduction in AP-laxity compared to pre-operative status by rolimeter testing (p = 0.002). Return to sport practice was achieved after mean 4.8 months (SD 4.1). CONCLUSIONS: ACL stump trephination and concomitant intra-ligamentary application of ACP revealed promising results at mid-term follow-up to treat partial ACL lesions.

Patient-related outcome of unstable pelvic ring fractures stabilized with a minimal invasive screw-rod system.

BACKGROUND: Clinical and radiological outcomes of operatively treated unstable pelvic ring fractures are well documented, whereas little is known about the patient's related outcome. The purpose of this study is to evaluate the patient-reported outcome after minimal invasive treatment of pelvic ring fractures using the SF-36 and EQ-5D medical outcome scores. METHODS: Patients with unstable pelvic ring fractures treated in our trauma department with a minimal invasive screw-rod system between 01/2004 and 12/2014 were included. Next to patient data (sex, age), injury related details (fracture type, additional injuries, Injury Severity Score (ISS)) as well as operation details (method, time to operation, general complications, adverse events associated with the surgical procedure, revision surgery, fracture reduction) were assessed. The patient related outcome was evaluated using the SF-36 and the EQ-5D score. RESULTS: A total of 105 patients (57 men; 48 women; mean age 56 ± 21 years) were identified as candidates for the study. 60 patients completed the SF-36 and EQ-5D score after a mean follow-up of five years (60.5 months (14-142 months)). Of these patients 77% were multiply injured with a mean ISS of 26 ± 19. Within the respondent group 22% showed type B and 78% type C pelvic ring fractures. In 82% the dorsal pelvic ring fracture was stabilized using a minimally invasive transiliac internal fixator, in 18% an iliolumbar fixation was performed respectively. The mean physical component score of the SF-36 was 37.9 ± 12.0, the mean mental component score was 49.8 ± 12.5. The mean EQ-5D VAS reached 70.5 ± 24.4. CONCLUSION: Patients being multiply injured and treated with minimal invasive treated dorsal pelvic ring fractures were suffering more especially concerning physical domains compared to the healthy reference population. Nevertheless, the overall patient-related outcome is comparable to pelvic ring fractures in general. TRIAL REGISTRATION NUMBER: Clinical Trial Registry University of Regensburg Z-2017-0878-3 . Registered 22. July 2017. Retrospectively registered.