ACL Injury

Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries, particularly in young and physically active individuals. Despite advances in reconstruction techniques, graft failure and rerupture remain clinically relevant. Revision ACL surgery is more complex than primary reconstruction and is associated with inferior outcomes, with rerupture rates of approximately 13%, reaching up to 25% when both subjective and objective failure criteria are considered. The main goal of ACL reconstruction is to restore anteroposterior and rotational knee stability, prevent secondary meniscal and cartilage damage, and enable return to sport. Surgical outcomes depend on several intraoperative factors, including graft choice and tunnel geometry, which are particularly relevant in revision settings. Diagnosis of ACL rerupture is primarily clinical, based on instability tests (Lachman, anterior drawer, pivot shift), and supported by instrumental assessment such as the KT-1000 arthrometer, which provides an objective measure of joint laxity. Revision ACL reconstruction can be performed using different surgical techniques (single-bundle, double-bundle, or combined extra-articular procedures) and graft types (autograft or allograft). Surgical strategy depends on multiple factors such as meniscal and cartilage status, previous surgery characteristics, tunnel positioning/enlargement, and fixation devices. However, no consensus exists regarding the optimal approach in terms of mid- to long-term outcomes. A major long-term complication is the development of osteoarthritis, particularly in this typically young and active patient population. Identification of modifiable factors, such as surgical technique and graft type, may help reduce failure risk and joint degeneration. This study aims to evaluate clinical and radiographic outcomes over a follow-up period exceeding two years in patients undergoing revision ACL reconstruction with different surgical techniques and graft types. The study also integrates objective knee laxity assessment using KT-1000 and markerless motion analysis based on artificial intelligence. Functional movements are recorded via video and analyzed using Sports2D software, enabling 2D kinematic analysis without markers or sensors, providing quantitative functional data to complement clinical and radiographic evaluation.

Hundreds of thousands of youth athletes require surgery for knee injuries annually. The incidence of operative knee injuries has skyrocketed, but surgery can be delayed due to late recognition and barriers, such as insurance, language, and difficulty navigating the healthcare system. Delays may have lifelong effects, including arthritis, persistent instability, poor patient reported outcomes, and reoperation. There is little patient-centered research on barriers to orthopaedic care, and none on interventions to reduce disparities in pediatric sports medicine. This study will focus on Hispanic children, a growing population nationally and 38% of the Chicago's children, who are at increased risk of delayed knee surgery and its sequelae compared to white, non-Hispanic patients. The overall objectives are to identify barriers to timely knee surgery in Hispanic athletes and develop an intervention to implement evidence on expedient treatment. The aim of this study is to evaluate feasibility, acceptability, and appropriateness of a culturally-tailored intervention in a pilot study of Hispanic youth soccer leagues. The proposed study will drive creation of a future community trial of a culturally-tailored intervention.

This is a multicenter randomized, placebo-controlled trial to assess whether a 6-month course of oral montelukast after ACL reconstruction reduces systemic markers of inflammation and biochemical and imaging biomarkers of cartilage degradation. This study will specifically target older ACL reconstruction patients with concomitant meniscal injuries as this group is at greatest risk of rapid PTOA progression. Patients will randomly be assigned to receive oral montelukast (10 mg) versus placebo daily for 6 months after surgery.

The overall aim of this multicenter RCT is to determine whether concomitant ALL reconstruction in children undergoing and ACL reconstruction will longitudinally result in a lower rate of graft failure than ACL reconstruction alone.

The goal of this prospective, cross-sectional study is to test the strength of the soleus muscle in participants who have a ACL tear confirmed by MRI. Previous studies have shown that the soleus muscle, which one of the muscles situated in the calf, decreases mechanical loading on the ACL. Therefore, we aim to test soleus muscle strength using a seated plantar flexor test. The main questions we aim to answer are: * Do patients with ACL tears demonstrate inter-limb soleus strength asymmetry (\>10%) * Do patients with ACL tears have soleus muscle weakness compared with uninjured (normative) participants? * Do changes in soleus strength values correlate with patient reported outcomes and stability, as measured by the IKDC questionnaire? To achieve this the VALD force frame will be used as the testing device for plantar flexor strength testing. This device records the force generated by the movement. This will be repeated three times on each leg as part of the testing procedure. Furthermore, as part of the testing procedure participants will be required to fill out an IKDC form to assess their knee stability. Interrater reliability of the force frame will be investigated. Further data from participants without ACL tears will be used to compare results. Thus allowing us to see if people with ACL tears have a weakness in the soleus muscle.

The aim of our study is to evaluate the effect of accelerated rehabilitation post ACL reconstruction with and without augmentation on graft healing and return to normal activity clinically by scoring system and radiologically.

This is a prospective, observational cohort study aimed at establishing a database of normative biomechanics for healthy athletes and surveying these athletes for 12 months following baseline testing for the occurrence of new musculoskeletal injuries, with a particular emphasis on ACL injuries.

Lower limb injuries represent the majority of sports-related injuries, with knee injuries being among the most common. In particular, anterior cruciate ligament (ACL) injuries are considered highly devastating and career-threatening for both professional and amateur athletes. Current surgical and rehabilitation treatments often fail to provide fully satisfactory short- and long-term outcomes. A very high risk of re-injury exists, especially in younger patients, with up to 35% experiencing a second ACL injury, alongside a significant long-term risk of early knee osteoarthritis. Most ACL injuries are non-contact or indirect contact injuries, implicating biomechanical factors and neuromuscular control as key determinants of injury mechanisms. Recent literature shows that patients suffering a non-contact ACL injury have a higher risk of re-injury compared to those with contact injuries, suggesting a significant cognitive component in injury processing, surgery, rehabilitation, and return to sport. Recent rehabilitation studies have introduced targeted neuromotor training designed to "rebuild" biomechanical and neuromuscular patterns to avoid mechanisms leading to re-injury. Movement quality tests are used post-training to confirm the reduction of risky biomechanical patterns, often resulting in a score indicating movement quality. Given the brain's involvement in such injuries, pioneering studies have used functional magnetic resonance imaging (fMRI) to investigate changes in cortical brain areas following ACL injury and reconstruction. Evidence shows adaptations in both central and peripheral nervous systems, with altered sensorimotor cortex activation in patients during simple motor tasks, differing from healthy subjects. Prefrontal cortex alterations correlate with severe quadriceps muscle activation asymmetries, linking these brain patterns to post-injury return-to-sport outcomes. However, no studies have yet evaluated the interaction between cortical activation (neural compensations) measured by fMRI and outcomes from targeted neuromotor training during ACL rehabilitation. Understanding brain activation implications is crucial for developing large-scale rehabilitation protocols to reduce the risk of a second, potentially more devastating, knee injury. This study aims to reveal whether a neuromotor training protocol can positively influence cognitive brain areas related to human movement, particularly by reducing risky injury patterns. It will be the first to test whether dedicated neuromuscular training effectively reduces neural compensations and cortical activation related to non-automated movement, favoring automation areas important for a safe return to sport. Patients will directly benefit from participating in the innovative neuromotor training program, with functional MRI scans conducted before training begins (post-surgery) and after training completion. Indirectly, the study will assess whether neuromotor training can adapt patient neuromotor patterns to reduce re-injury risk, ultimately benefiting future patients undergoing ACL reconstruction.

The study is intended to include all patients who will undergo surgical reconstruction of the anterior cruciate ligament (ACL). The patients will be monitored and evaluated preoperatively and also at 6 months and 1, 2 and 5 years after the intervention through a clinical visit or telephone interview. Such assessments will include the administration of questionnaires to determine the patient's functional symptoms and the objective examination of the knee during a medical examination to quantify its stability.

Submission of the KOOS ACL questionnaires in Italian for the purpose of validation and cultural adaptation of the KOOS-ACL scale for the Italian population.

This study will utilize the Moxy wearable sensor to measure muscle oxygen saturation levels in athletes following lower extremity surgery (ACL or Hip arthroscopy) to evaluate their Return-to-Play. The acquired data will complement current protocols utilized by Dr. Voos and Dr. Salata in this regard and will add quantifiable evidence to enable a robust measurement of the surgical limb versus non-surgical limb.

Clinical evaluation for the patients with partial ACL tear who had ACL augmentation

The purpose of this study to investigate the effect of using losartan (a blood pressure lowering drug with anti-scarring properties) on preventing primary postoperative arthrofibrosis (formation of abnormal scar tissue) in the knees in participants undergoing anterior cruciate ligament (ACL) repair surgery of their knee.

The goal of this pilot randomized clinical trial is to look into the efficacy of concentrated bone marrow aspirate (cBMA) in improving post traumatic osteoarthritis (PTOA) symptoms in patients undergoing revision anterior cruciate ligament reconstruction surgery. The main questions it aims to answer are whether clinical outcomes, such as pain, are improved in patients who get cBMA with surgery, if there is a change in circulating markers of inflammation and what part of the cellular and molecular composition of cBMA may explain its effects.

The purpose with this present study is to investigate the effect og a non-surgical regime in patients with an Anterior Cruciate ligament injury. The effect will be measured by patient reported outcome scores, level of function and how many of the patients are converting to operative treatment.

The goal of this study is to gather pilot data to help inform a future clinical trial. As such, the investigators will employ a randomized clinical trial design, but data will only be collected on 9 total subjects. Nine subjects will be randomized to 2 split-belt intervention groups (one group where early stance loading is trained and the other where midstance loading is trained) and a placebo group. The goal of this study is to explore the adaptations in knee loading from a 6-week split-belt training intervention. The investigators' main question for this aim is: 1. Does knee loading, measured by the sagittal plane knee moment, change to a greater extent in the split-belt treadmill training groups compared to the placebo group? 2. Are there differences in training-related knee loading changes between individuals trained in the early stance vs. midstance loading split-belt training?

A major complication after cruciate ligament injury and surgery is arthrogenic muscle inhibition of the quadriceps, which is characterised by a deficit in voluntary muscle activation in the affected leg. This can hinder rehabilitation processes, lead to impaired knee function, and negatively impact the patients' quality of life. The primary objective of this study is to assess whether voluntary quadriceps activation on the injured side is facilitated by the concomitant application of neuromuscular electrical stimulation (NMES) on the contralateral quadriceps.

This study aims to evaluate and compare the acute effects of Kinesio taping applied to the knee and ankle on balance, proprioception, and anterior cruciate ligament (ACL) injury risk using the Landing Error Scoring System (LESS). Designed as a randomized crossover trial, the study will include 24 healthy volleyball athletes with at least 5 years of experience. All participants will receive both ankle and knee taping interventions, separated by a one-week washout period. Assessments will be conducted at four time points: before and after each taping. Outcome measures include the Y-Balance Test, proprioception tests, and LESS.

This study aims to investigate the association between femoral notch morphology, as assessed by MRI, and the risk of ACL injury

Muscle haemodynamics has so far been assessed using at most 2-3 near-infrared spectroscopy devices on isolated muscles and without correlating variables. At the same time, research on musculoskeletal pathologies is limited, and there are no studies that analyse the haemodynamic changes that occur when the anterior cruciate ligament (ACL) is injured and whether these changes last over time. The aim of the study is to monitor and evaluate the physiological changes produced by ACL injury on muscle performance using non-invasive near-infrared spectroscopy (NIRS) devices in trained athletes. This descriptive cross-sectional observational multicentre multicentre study, with Balearic Islands ethics committee IB 5585/24PI, will include males aged 18-65 years who have undergone ACL surgery, divided into 3 groups that: have an evolution of less than 6 months (ACL1), more than 2 years since the surgical intervention and are already practising normal physical-sports activities (ACL2) and the control group (CON) that has never suffered an ACL affectation to date. The 3 groups will perform an incremental intervallic test (4:1) on a cycloergometer or treadmill (according to the specificity of their sport), where different muscular haemodynamic variables will be assessed using 12-24 NIRS devices. The main study variables will be the muscular haemodynamic values of each muscle analysed and their correlation between them: muscular oxygen saturation, absolute capillary haemoglobin, loaded and unloaded with oxygen and relative muscular haemoglobin blood flow, loaded and unloaded with oxygen. Secondary variables will be heart rate, socio-demographic variables (age, toxic habits, injury and sports history) and subjective perception of effort (RPE-20).

The aim of this study is to investigate the differences in graft failure between patients that underwent ACL reconstruction using allograft tendons and patients that underwent ACL reconstruction using autograft tendons in patients older than 40 y.o. and after at least 2 years of follow-up. The hypothesis of the study is that there will be a difference in graft failure and patient reported functional outcomes between allograft and autograft ACL reconstruction.

The anterior cruciate ligament (ACL) injury is common in athletes aged 18 to 35. ACL reconstruction (ACLR) aims to restore knee stability in the process of returning to sports. Post-surgical rehabilitation focuses on optimizing biomechanical parameters, with neuromuscular and functional tests assessing muscle strength, proprioception, and dynamic stability. Isokinetic allows the measurement of muscle strength symmetry and proprioception, while the single-leg hop and landing tasks assess functional stability and are predictive of sports resumption and injury prevention. Despite progress, concerns remain about neuromuscular factors impacting knee stability, especially during landings, which can increase the risk of secondary ACL injuries. This study proposes examining knee strength and proprioception using isokinetic dynamometry, alongside biomechanical assessments from functional tests, to explore their relationship to biomechanical features during landings, at 6-to-12 months post-ACL reconstruction. The hypothesis is that better muscle strength and proprioception correlate with improved knee control during landing tasks.

Anterior cruciate ligament (ACL) injuries are common in sports and often require a long and challenging rehabilitation process. Athletes who sustain these injuries typically engage in pivoting and cutting sports, where these motor tasks must be performed simultaneously with cognitive tasks such as decision-making and keeping an eye on the opponent. Directing attention to both cognitive and motor tasks leads to cognitive-motor interference, which is associated with movement patterns that increase the risk of ACL (re)injury. Therefore, it is crucial that before returning to such demanding sports after ACL reconstruction, athletes sufficiently develop and automate safe yet efficient motor skills to free up attentional capacity for decision-making, thereby reducing the risk of suboptimal movement patterns and reinjury. However, current rehabilitation programs often primarily focus on the motor component in a single-task manner, giving insufficient attention to the cognitive component that is inseparable from sports. This randomized controlled trial aims to investigate the effects of implementing motor-cognitive dual tasks in the end phase rehabilitation after ACL reconstruction on muscle function, functional outcomes, and patient-reported outcomes.

The goal of this observational study is to explore the significance of subject-reported outcomes and clinical parameters in relation to the occurence of prolonged presence of arthrogenic muscle responses (AMR) in anterior cruciate ligament (ACL) reconstructed patients. The main questions it aims to answer are: 1\. Is there a link between the long-term occurence of AMR in ACL reconstructed patients and the level of kinesiophobia experienced before or after their ACL surgery? We hypothesize that ACL patients with higher levels of kinesiophobia are more likely to exhibit prolonged AMR as an unconscious reaction to protect their affected knee joint. 2\. Is the long-term presence of AMR in ACL reconstructed patients linked to their subjective knee function and stability (at certain time points throughout their recovery)? Our hypothesis is that poorer subjective knee function and stability might be associated with the presence of prolonged arthrogenic muscle responses in ACL reconstructed patients. 3\. Is the prolonged presence of AMR in ACL reconstructed patients linked to their pain levels (at certain time points throughout their recovery)? Our hypothesis is that ACL patients with higher pre- and/or postsurgical pain levels may exhibit a higher degree of long-lasting AMR. 4\. Is the long-term presence of AMR in ACL reconstructed patients linked to clinical parameters such as swelling, isometric quadriceps and hamstrings strength and knee range of motion (at certain time points throughout their recovery)? Our hypothesis is that ACL patients with poorer outcomes in terms of these clinical parameters may be more likely to exhibit prolonged AMR. Participants will: * Fill in the following questionnaires 1 week before surgery and at 1 and 3 months after surgery: * Demopgraphical information * Knee Injury and Osteoarthritis Outcome Score (KOOS) * Lysholm Score (only question 1) * Tegner Activity Scale (current activity level, pre-injury activity level and desired activity level after recovery) * Numeric Rating Score (NRS) for pain levels during the day \& during the night * ACL-Return to Sport after Injury Scale (ACL-RSI) * Complete a testing protocol 5 months after their surgery, which includes bilateral electromyographical measurements of the hamstrings and quadriceps during jumping tasks and a quadriceps inhibition measurement using the interpolated twitch method to evaluate the presence of prolonged AMR.

Currently, most patients with an anterior cruciate ligament injury undergo surgery. There is a general belief that surgical reconstruction is necessary to safely return to sports and to prevent early knee osteoarthritis or additional meniscus injuries. But there is insufficient scientific evidence to support this belief. Moreover, several studies show that surgical reconstruction of the cruciate ligament does not guarantee successful return to sports or the prevention of osteoarthritis and secondary meniscus injuries. Therefore, immediate surgery after an anterior cruciate ligament injury is questioned. So far, only two RCTs (KANON study and COMPARE study) have assessed this, and they could not show that immediate reconstruction is an added value (in terms of symptoms, knee function, activity level, osteoarthritis or additional meniscal injuries) compared to a conservative approach consisting of rehabilitation and late surgery for persistent knee instability. Therefore, this additional multicenter RCT, aims to 1) verify these results and 2) to identify predictors that predict which patients in the conservative group will not require late surgery. This has not been investigated to date. It is suspected that factors such as symptoms, strength, findings on the MRI scan and psychological factors may play a role in whether or not a patient will be able to successfully rehabilitate without surgical repair. This information is invaluable to physicians because it allows them to decide which treatment is best for the patient.