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Concept: Anterior cruciate ligament injury


The effects of hip muscle strength and activation on anterior cruciate ligament injury biomechanics, particularly knee valgus loading, have been reported in isolation and with equivocal results. However, the combination of these factors influences joint biomechanics. This investigation evaluated the influence of hip strength on gluteal activation and knee valgus motion. Maximal isometric hip abduction (ABD) and external rotation (ER) contractions were used to define High and Low strength groups. Knee kinematics and gluteus maximus (GMax) and medius (GMed) EMG amplitudes obtained during landing were compared between High and Low strength groups after controlling for the potential confounding influence of sex. Knee valgus motion did not differ between the High and Low hip ABD and ER strength groups. However, the Low ABD and ER strength groups displayed greater GMed and GMax EMG amplitudes, respectively, compared to the High strength groups. These findings suggest that weaker individuals compensate for a lack of force production via heightened neural drive. As such, hip muscle strength influences knee valgus motion indirectly by determining neural drive requirements.

Concepts: Knee, Anterior cruciate ligament, Electromyography, Muscular system, Ligament, Anterior cruciate ligament injury, Cruciate ligament, Gluteal muscles


Clinical features of anterior cruciate ligament (ACL) injury are important for its prevention, diagnosis and treatment. However, few studies have reported such data, especially in China. The purpose of this study was to describe the clinical characteristics of ACL injury on a large cohort.

Concepts: Knee, Anterior cruciate ligament, Cultural studies, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Ligaments


In October 2017, the International Olympic Committee hosted an international expert group of physiotherapists and orthopaedic surgeons who specialise in treating and researching paediatric ACL injuries. Representatives from the American Orthopaedic Society for Sports Medicine, European Paediatric Orthopaedic Society, European Society for Sports Traumatology, Knee Surgery & Arthroscopy, International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine, Pediatric Orthopaedic Society of North America and Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte attended. Physiotherapists and orthopaedic surgeons with clinical and research experience in the field, and an ethics expert with substantial experience in the area of sports injuries also participated. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision-making with children and the potential long-term ramifications of the injury. This consensus statement addresses six fundamental clinical questions regarding the prevention, diagnosis and management of paediatric ACL injuries. The aim of this consensus statement is to provide a comprehensive, evidence-informed summary to support the clinician, and help children with ACL injury and their parents/guardians make the best possible decisions.

Concepts: Medicine, Surgery, Physician, Knee, Anterior cruciate ligament, Anterior cruciate ligament injury, Cruciate ligament, Arthroscopy


Clinical trials have demonstrated that preventive neuromuscular training (PNMT) can be effective to reduce ACL injuries in young females. However, the magnitude of the overall effect of PNMT for ACL injury reduction has not reached consensus. In addition, the effects of individual exercises in PNMT that optimise ACL injury reduction are unknown.

Concepts: Clinical trial, Medical statistics, Effect, Effectiveness, Knee, Anterior cruciate ligament, Anterior cruciate ligament injury, Cruciate ligament


The Royal Dutch Society for Physical Therapy (KNGF) instructed a multidisciplinary group of Dutch anterior cruciate ligament (ACL) experts to develop an evidence statement for rehabilitation after ACL reconstruction.

Concepts: Evidence-based medicine, Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Hamstring


Graft survivorship, reinjury rates, and career length are poorly understood after anterior cruciate ligament (ACL) reconstruction in the elite collegiate athlete. The purpose of this study was to examine the outcomes of ACL reconstruction in a National Collegiate Athletic Association (NCAA) Division I athlete cohort.

Concepts: Knee, Anterior cruciate ligament, College football, Ligament, Anterior cruciate ligament injury, Cruciate ligament, Division I, Ivy League


A controversial discussion is held on using stabilizing knee braces after anterior cruciate ligament (ACL) surgery. The current study investigated the influence of a stabilizing knee brace on results after ACL reconstruction using patellar tendon autografts.

Concepts: Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Hamstring, Lateral meniscus


Surgery involving arthroscopic reconstruction of the injured ligament is the gold standard treatment for torn anterior cruciate ligament (ACL). Recent studies support the hypothesis of biological self-healing of ruptured ACL. The aim of the study is to evaluate, in an animal model, the efficacy of a new technique, dynamic intraligamentary stabilization that utilizes biological self-healing for repair of acute ACL ruptures.

Concepts: Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Arthroscopy


E.A. JOY, J.R. TAYLOR, M.A. NOVAK, B. FINK, , M. CHEN, and C.A. PORUCZNIK. Females are three times more likely to injure their anterior cruciate ligament (ACL) while playing soccer than males. ACL injury prevention programs (IPP) involving stretching and strengthening drills can reduce the incidence of ACL injury when incorporated into routine training. The rate of implementation among coaches is largely unknown. The purpose of this study is to determine the rate of implementation of ACL IPP, to identify factors that influence implementation, and to acquire information to assist in design dissemination and implementation strategies. Study subjects were coaches of female soccer players age 11 - 22 years in Utah (n=756). Data was gathered using a web-based survey, followed by a qualitative study in which “best practice coaches”-coaches who met criteria for successful implementation of ACL IPP-were interviewed via telephone. A minority of survey respondents, 19.8% (27/136), have implemented ACL IPP. Factors associated with successful implementation include length of coaching experience and presence of additional support staff such as a strength and conditioning coach or athletic trainer. “Best practice coaches” (14/136) unanimously agreed on the following: (1) there are performance-enhancing benefits of ACL IPP; (2) education on ACL injury prevention should be required for licensure; and (3) dissemination and implementation will require soccer associations to enact policies that require injury prevention programs. In conclusion, a minority of girls soccer coaches have implemented ACL IPP and those that have do so because they believe prevention improves performance and that soccer organizations should enact policies requiring ACL injury prevention education and implementation. Efforts to implement ACL IPP should be driven by soccer organizations, emphasize performance-enhancing benefits, and engage additional coaching staff.

Concepts: Female, Knee, Anterior cruciate ligament, Implementation, Ligament, Anterior cruciate ligament injury, Cruciate ligament, Injury prevention


STUDY DESIGN: Within and between subject cross sectional study. OBJECTIVES: To investigate symmetry in hop test performance, strength, and lower extremity kinematics 6-9 months post anterior cruciate ligament reconstruction (ACLR). BACKGROUND: Despite the extensive body of literature in persons following ACLR, no study has comprehensively evaluated measures of strength, lower extremity kinematics and functional performance of hop tests in this population. METHODS: 22 men (age, 28.8± 11.2 years) 6-9 months (7.01±0.93) following ACLR using a bone-patella tendon bone autograft and 22 healthy men (24.8 ± 9.1 years) participated. Participants completed a self-reported questionnaire and underwent isokinetic strength testing and functional and kinematic assessment of the single, triple, and crossover hop tests. Two-way ANOVAs were used to test for differences between the ACLR group and the control group and between the two lower extremities of the ACLR group. RESULTS: Compared to the control group, the ACLR group had greater isokinetic knee extension torque deficits at all speeds (p≤0.001) and greater performance asymmetry for all 3 hop tests (p<0.001). Compared to the intact lower extremity, the involved lower extremity of the ACLR group exhibited less ankle dorsiflexion and knee flexion at propulsion (p≤0.014) and landing phases (p≤0.032). When compared to the control group the involved lower extremity exhibited less ankle dorsiflexion in the propulsion phase (p<0.001) but higher hip flexion in the landing phase (p=0.014). CONCLUSION: Patients following ACLR demonstrate functional hop and isokinetic knee extension deficits as well as kinematic differences during the propulsion and landing phases of the hop tests at 6-9 months after surgery.J Orthop Sports Phys Ther. Epub 14 January 2013. doi:10.2519/jospt.2013.3967.

Concepts: Knee, Anterior cruciate ligament, Extension, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Hamstring