Development of a test battery to enhance safe return to sports after anterior cruciate ligament reconstruction

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Machine learning methods in sport injury prediction and prevention: a systematic review

Purpose: Injuries are common in sports and can have signifcant physical, psychological and fnancial consequences. Machine learning (ML) methods could be used to improve injury prediction and allow proper approaches to injury prevention. The aim of our study was therefore to perform a systematic review of ML methods in sport injury prediction and prevention. Methods: A search of the PubMed database was performed on March 24th 2020. Eligible articles included original studies investigating the role of ML for sport injury prediction and prevention. Two independent reviewers screened articles, assessed eligibility, risk of bias and extracted data. Methodological quality and risk of bias were determined by the Newcastle–Ottawa Scale. Study quality was evaluated using the GRADE working group methodology. Results: Eleven out of 249 studies met inclusion/exclusion criteria. Diferent ML methods were used (tree-based ensemble methods (n=9), Support Vector Machines (n=4), Artifcial Neural Networks (n=2)). The classifcation methods were facilitated by preprocessing steps (n=5) and optimized using over- and undersampling methods (n=6), hyperparameter tuning (n=4), feature selection (n=3) and dimensionality reduction (n=1). Injury predictive performance ranged from poor (Accuracy=52%, AUC=0.52) to strong (AUC=0.87, f1-score=85%). Conclusions: Current ML methods can be used to identify athletes at high injury risk and be helpful to detect the most important injury risk factors. Methodological quality of the analyses was sufcient in general, but could be further improved. More efort should be put in the interpretation of the ML models

Surgical technique: posterior cruciate ligament (PCL) reconstruction using double posteromedial arthroscopic portals

The posterior cruciate ligament (PCL) reconstruction is a technically demanding surgical procedure that requires optimal identification of both the femoral and the tibial anatomical footprints. To aid the tibial tunnel placement and many authors recommend creating a posteromedial (PM) portal. The further addition of a second PM portal, which could be used as a "working portal", may further allow a more straightforward reconstruction by improving the identification of the anatomical footprint, the clearing of the stump, and the graft passage

Cartilaginous tibial eminence fractures in children: which recommendations for management of this new entity ?

PURPOSE: Cartilaginous tibial eminence fracture (CTEF) is a new pattern of ACL rupture in children under the age of nine. MRI signs have been recently reported, but no series gave information about outcomes. It was hypothesized that primary treatment gave better results than delayed management due to frequent misdiagnosis. METHOD: This retrospective study focused on 15 patients, managed acutely (n = 7) or delayed (n = 8). The patients' median age at the time of initial injury was 6.5 years (range 5-9). Lysholm, IKDC 2000 subjective scores, and the measurement of the residual laxity by a side-to-side difference with a KT-1000 junior arthrometer were used at the time of revision. RESULTS: After a mean follow-up of 9.8 years (range 1-18.5), the mean Lysholm and IKDC subjective scores were, respectively, 97.7 ± 2.6 and 97 ± 3.4. The median residual laxity was 2 mm (range 0-4). Non-operative treatment lead to 2 failures: intermeniscal ligament entrapment and combined avulsion fracture at the femoral site. Suture fixation of the avulsed fragment allows regularly good results when performed acutely or even 4 years after the injury. The hypothesis that primary treatment gives better result than delayed treatment tends to be wrong as 2 failures were reported in each group. An ACL reconstruction was performed in 3 out of the 4 treatment failures. Progressive resorption of the avulsed fragment was noticed in 3 of the 4 failures suggesting an associated ACL resorption. CONCLUSION: CTEF has a good prognosis even after misdiagnosis and treatment at the time of non-union; this could be due to low-energy mechanism of injury and low rate of associated lesion. Orthopaedic treatment for acute minimally displaced fractures is only indicated under strict MRI control, and suture fixation is the recommended strategy in other situations. Conservative management of non-union could expose to ACL involution and cannot be recommended. LEVEL OF EVIDENCE: Retrospective case series, Level IV

Epidemiology of injuries in high-level youth sport in Luxembourg [Abstract]

peer reviewe

A novel approach to enhance ACL injury prevention programs

Abstract Efficacy studies have demonstrated decreased anterior cruciate ligament (ACL) injury rates for athletes participating in injury prevention programs. Typically, ACL injury prevention programs entail a combination of plyometrics, strength training, agility and balance exercises. Unfortunately, improvements of movement patterns are not sustained over time. The reason may be related to the type of instructions given during training. Encouraging athletes to consciously control knee movements during exercises may not be optimal for the acquisition of complex motor skills as needed in complex sports environments. In the motor learning domain, these types of instructions are defined as an internal attentional focus. An internal focus, on one’s own movements results in a more conscious type of control that may hamper motor learning. It has been established in numerous studies that an external focus of attention facilitates motor learning more effectively due to the utilization of automatic motor control. Subsequently, the athlete has more recourses available to anticipate on situations on the field and take appropriate feed forward directed actions. The purpose of this manuscript was to present methods to optimize motor skill acquisition of athletes and elaborate on athletes’ behavior

Sports injuries and risk factors in youth soccer [Abstract].

peer reviewe

Möglichkeiten und Perspektiven zum Einsatz der künstlichen Intelligenz in der Sportorthopädie

peer reviewedIn many scientific fields, the growth of knowledge is progressing extremely rapidly. However, this also requires new techniques to identify relevant data from the mass of evidence. Scientific evidence can help improve therapeutic decision-making as well as injury prevention and optimize return to sport activity. Artificial intelligence (AI) enables these processes to be significantly assisted. As these new concepts are known to very few orthopedic surgeons and sports physicians, this article will explain basic concepts of AI, clarify differences with classical statistics, and describe its potential applications in sports orthopedics

Altered movement during single leg hop test after ACL reconstruction:implications to incorporate 2-D video movement analysis for hop tests

Purpose There is a lack of objective factors which can be used in guiding the return to sport (RTS) decision after an anterior cruciate ligament reconstruction (ACLR). The purpose of the current study was to conduct qualitative analysis of the single leg hop (SLH) in patients after ACLR with a simple and clinical friendly method and to compare the possible difference in movement pattern between male and female patients. Methods Sixty-five patients performed the single leg hop (SLH) test at 6.8 +/- 1.0 months following isolated ACLR. Digital video camcorders recorded frontal and sagittal plane views of the patient performing the SLH. Knee flexion at initial contact (IC), peak knee flexion, knee flexion range of motion (RoM), and knee valgus RoM were calculated. In addition, limb symmetry index (LSI) scores were calculated. Results No differences were found in movement pattern between males and females. Movement analysis revealed that males had a decrease in knee flexion at IC (p = 0.018), peak knee flexion (p = 0.002), and knee flexion RoM (p = 0.017) in the injured leg compared to the non-injured leg. Females demonstrated a decrease in peak knee flexion (p = 0.011) and knee flexion RoM (p = 0.023) in the injured leg compared to the non-injured leg. Average LSI scores were 92.4% for males and 94.5% for females. Conclusions Although LSI scores were > 90%, clinical relevant altered movement patterns were detected in the injured leg compared to the non-injured leg. Caution is warranted to solely rely on LSI scores to determine RTS readiness

Low rates of patients meeting return to sport criteria 9 months after anterior cruciate ligament reconstruction:a prospective longitudinal study

Purpose The purpose of the current prospective study was to assess the changes over time in patients tested at 6 months and 9 months after anterior cruciate ligament reconstruction (ACLR) with a return to sport (RTS) test battery. It was hypothesized that more patients passed RTS criteria at 9 months compared to 6 months. Methods Sixty-two ACLR patients performed a test battery at an average of 6.5 +/- 0.7 and 9.5 +/- 0.9 months after ACLR. All patients underwent a standardized rehabilitation protocol. The test battery consisted of the following tests: a jump-landing task assessed with the Landing Error Scoring System (LESS), three single-leg hop tasks (single-leg hop test, triple-leg hop test, side hop test), isokinetic quadriceps and hamstring strength at 60, 180 and 300 degrees/s and two questionnaires (IKDC and ACL-RSI). Cut off criteria were set as Limb Symmetry Index (LSI)>90% (for isokinetic strength and for single-leg hop tasks), LESS56 respectively. Results At 6 months, two patients (3.2%) passed all criteria. At 9 months, seven patients (11.3%) passed all criteria. Patients improved in all RTS criteria over time except for the IKDC score. Twenty-nine patients (46.8%) did not pass the strength criterion at 60 degrees/s at 9 months after ACLR. Conclusions The percentages of patients passing all RTS criteria were low at both 6 and 9 months after ACLR. Quadriceps strength revealed persistent deficits and the lack of improvement in the IKDC score questionnaires shows insufficient self-reported knee function for RTS