Changes in the Force-velocity Relationship of Knee Muscles After ACL Reconstruction

Study Overview
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Brief Summary
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Anterior cruciate ligament (ACL) tear is a frequent and devastating injury in sport, especially in pivoting-contact disciplines. In many cases, athletes will undergo an ACL reconstruction (ACL-R) for recovering knee stability, preventing further injuries and returning to sport (RTS). Among the criteria for RTS, knee muscle strength is the most used objective criteria and especially the symmetry of knee flexors and/or extensors between the operated and uninjured knee. Isokinetic testing of knee muscle strength is considered as a reference for knee muscle testing during the follow up stages after ACL-R. This evaluation allows to measure the strength (torque) of knee flexors and extensors at several angular velocities. However, there is no relevant litterature about the force-velocity (Fo-v) relationship of knee flexors and extensors after ACL-R. The present study aimed to evaluate and test the differences between the Fo-v relationship parameters between the operated and uninjured knees at 4 months and 8 months after ACL-R, using the 2-points method with isokinetic testing. Also, the investigators aimed to test the impact of the type of surgery (patellar tendon autograft vs. hamstring tendon autograft) on the Fo-v relationship after ACL-R

Official Title
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Changes in the Force-velocity Relationship of Knee Muscles After ACL Reconstruction

Conditions
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Anterior Cruciate Ligament Injuries, Muscle Weakness

Intervention / Treatment
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* Other: Follow-up after Anterior cruciate ligament reconstruction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who have had an ACL reconstruction surgery (isolated or associated with other meniscal or ligamentary surgery) Patient included in the sport medicine follow-up protocole with intermediate and final isokinetic muscular assessment at 4 months and8 months after surgery respectively Patients who completed both tests at the 60°/s and 240°/s velocities Exclusion Criteria: Patient who did not participate in all follow-up consultations and isokinetic muscular assessments Cognitive or sensory impairment making it impossible to understand the information form Neurological, traumatic or osteoarticular history responsible for muscle imbalance prior to surgery

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ACL group<br>The patients were referred to the sport medicine department for the post ACL-R follow-up including isokinetic knee muscle strength evaluations at 4 months and 8 months after the surgery | Other: Follow-up after Anterior cruciate ligament reconstruction<br>* The patients were referred to the sport medicine department for the post ACL-R follow-up including isokinetic knee muscle strength evaluations at 4 months and 8.months after the surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in strength | Measurement of knee extensors and flexors peak strength (in newton.meter, Nm) on isokinetic dynamometer at two angular velocities of 60°/s and 240°/s respectively | Time Frame: ACL group: Two evaluations on both injured and healthy knees: (1) 4 months after surgery and (2) 8 months after surgery; Routine practice following guidelines | 
| Change in the force-velocity relationship | Calculation of the corresponding slope and maximal force (Y-intercept) of the regression line of the force-velocity curve | Time Frame: ACL group: Two evaluations on both injured and healthy knees: (1) 4 months after surgery and (2) 8 months after surgery; Routine practice following guidelines | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Individual characteristics | Personal characteristics recorded in the medical report as age, gender, type of sport and sport level of practice and return to sport after the surgery | Time Frame: ACL group: Two evaluations on both injured and healthy knees: (1) 4 months after surgery and (2) 8 months after surgery; Routine practice following guidelines | 
| Injury characteristics | Injury characteristics recorded in the medical report as the type of injury (ACL only, ACL and meniscus, ACL with other ligament injury, recurrent ACL injury) the time before surgery, the type of rehabilitation before and after surgery | Time Frame: ACL group: Two evaluations on both injured and healthy knees: (1) 4 months after surgery and (2) 8 months after surgery; Routine practice following guidelines | 
| Surgery characteristics | Surgery characteristics recorded in the medical report as the type of surgery, the surgery duration and tourniquet time | Time Frame: ACL group: Two evaluations on both injured and healthy knees: (1) 4 months after surgery and (2) 8 months after surgery; Routine practice following guidelines |