Aquatic Training after Joint Immobilization in Rats Promotes Adaptations in Myotendinous Junctions.

The myotendinous junction (MTJ) is the muscle-tendon interface and constitutes an integrated mechanical unit to force transmission. Joint immobilization promotes muscle atrophy via disuse, while physical exercise can be used as an adaptative stimulus. In this study, we aimed to investigate the components of the MTJ and their adaptations and the associated elements triggered with aquatic training after joint immobilization. Forty-four male Wistar rats were divided into sedentary (SD), aquatic training (AT), immobilization (IM), and immobilization/aquatic training (IMAT) groups. The samples were processed to measure fiber area, nuclear fractal dimension, MTJ nuclear density, identification of telocytes, sarcomeres, and MTJ perimeter length. In the AT group, the maintenance of ultrastructure and elements in the MTJ region were observed; the IM group presented muscle atrophy effects with reduced MTJ perimeter; the IMAT group demonstrated that aquatic training after joint immobilization promotes benefits in the muscle fiber area and fractal dimension, in the MTJ region shows longer sarcomeres and MTJ perimeter. We identified the presence of telocytes in the MTJ region in all experimental groups. We concluded that aquatic training is an effective rehabilitation method after joint immobilization due to reduced muscle atrophy and regeneration effects on MTJ in rats.

Injury Patterns, Risk Factors, and Return to Sport in Brazilian Jiu Jitsu: A Cross-sectional Survey of 1140 Athletes.

BACKGROUND: Brazilian jiu jitsu (BJJ) is a growing martial art that focuses on grappling techniques. PURPOSE: To quantify the 3-year incidence of BJJ-related injuries and detect common injury patterns as well as risk factors among those practicing BJJ. It was hypothesized that there would be a high incidence of injuries, they would be caused by submissions in sparring situations, and they would occur predominantly at the extremities. STUDY DESIGN: Descriptive epidemiology study. METHODS: Active BJJ athletes were invited to take an English-language online survey developed by orthopaedic surgeons together with BJJ athletes and a sports scientist. Data were recorded regarding athlete demographics, sporting activity level, injuries within the past 3 years that caused at least a 2-week time loss, injury mechanisms, and return to sport. RESULTS: Overall, 1140 responses were received from 62 different countries; 88.9% of all athletes were male, and 63.9% were regular competitors. Within the investigated cohort, 1052 injuries were recorded in 784 athletes, for an injury incidence of 308 per 1000 athletes per year. The lower extremity (45.7%) and upper extremity (30.2%) were predominant sites of injury, with injuries to the knee (27.1%) being the most common. The most frequent knee injuries were meniscal injuries (n = 65), anterior cruciate ligament (ACL) tears (n = 36), and medial collateral ligament injuries (n = 36). ACL tears were especially associated with long time frames for return to sport. Most injuries occurred during sparring (77.6%) and were caused by submissions (29.7%) and takedowns (26.4%). Competing regularly (P = .003), older age (P < .001), and higher belt rank (P = .003) were significant risk factors for injury. CONCLUSION: Injury incidence was high among BJJ athletes surveyed, with 2 out of 3 athletes reporting at least 1 injury within a 3-year period that caused a 2-week absence from training. Most injuries occurred during sparring, and we believe that a high potential for injury reduction lies in drawing awareness to common injury patterns and sites in athletes.

Patellar sleeve avulsion fracture in a patient with Sinding-Larsen-Johansson syndrome: a case report.

BACKGROUND: Patellar sleeve avulsion (PSA) fractures are rare injuries that occur in in skeletally immature patients. Initial diagnosis is key to a successful outcome, as these injuries are easily overlooked on plain radiographs with poor results well documented from delayed management. High index of suspicion from the mechanism of injury, thorough clinical examination and Magnetic Resonance Imaging (MRI) help to avoid misdiagnosis. CASE PRESENTATION: The case of a 12-year-old male athlete with an acute PSA after a conservative treatment of a SLJ syndrome is described. The patient was referred to our clinic due to severe pain and loss of function after performing a high jump. Plain radiographs (X-ray) and MRI confirmed an inferior pole PSA which was fixed with double trans osseous ultra-high strength tapes. At the 3-month follow- up visit the patient was able to ambulate brace free. At 2-years follow up the patient was able to play soccer and ice hockey. To our knowledge, there are no case reports of inferior pole PSA with prior SLJ syndrome described in literature. CONCLUSIONS: Early clinical suspicion and distinguishing this PSA from other enchondral ossification disorders around the knee is critical to avoid misdiagnosis. Whether SLJ syndrome increases the risk of sustaining a PSA is still not clear. Trans osseous fixation with suture tapes leads to good functional results in a young athlete with inferior pole PSA.

Putative ATP-binding cassette transporter is essential for Brucella ovis pathogenesis in mice.

Brucella ovis is a major cause of reproductive failure in sheep, which is associated with epididymitis and infertility in rams. Importantly, B. ovis is one of the few Brucella species that is not zoonotic. Due to the scarcity of studies on B. ovis infection, a murine model of infection was developed. The roles of B. ovis genes encoding a putative hemagglutinin and an ABC transporter were investigated in the mouse model. The kinetics of B. ovis infection were similar in BALB/c and C57BL/6 mice, and both strains of mice developed multifocal microgranulomas in the liver and spleen, but only minimal colonization and histopathological changes were observed in the genital tract. Therefore, the mouse was considered a suitable infection model for B. ovis but not for B. ovis-induced genital disease. Two mutant strains were generated in this study (the ΔabcAB and Δhmg strains). The B. ovis ΔabcAB strain was attenuated in the spleens and livers of BALB/c mice compared to the wild-type (WT) strain (P < 0.001). Conversely, the Δhmg strain infected mice at the same level as WT B. ovis, suggesting that a putative hemagglutinin is not required for B. ovis pathogenesis. Additionally, the ΔabcAB strain did not survive in peritoneal macrophages, extracellularly in the peritoneal cavity, or in RAW 264.7 macrophages. Moreover, infection with the ΔabcAB strain was not lethal for male regulatory factor 1-knockout mice, whereas infection with the B. ovis WT strain was 100% lethal within 14 days postinfection. These results confirm that the predicted ABC transporter is required for the full virulence and survival of B. ovis in vivo.