Clinical Trials

The purpose of this study is to investigate the effects of multimodal perioperative educational resources including a typical preoperative consultation with the surgeon, this same consultation in conjunction with a concise, informative video, worksheet, and quiz, and this same consultation in conjunction with a one time in-person educational session with worksheet and quiz.

The overall primary objective of this 21-site international randomized trial is to determine if graft type (QT, BPTB or HT) with or without a lateral extra-articular tenodesis (LET) will affect the rate of Anterior Cruciate Ligament (ACL) clinical failure 2 years after surgery.

The purpose of this study is to analyze the difference between the Blood Flow Restriction (BFR) and SHAM-BFR groups in change in muscle diameter (hypertrophy) from 2 weeks pre-operative to 8-10 days post-operative.

The overall goal of this project is to reduce risk of second anterior cruciate ligament (ACL) injury in vulnerable populations (active athletes between 14 = 24 years old) through the identification of relative injury risk groups based on subject-specific movement patterns prior to second injury, as well as through the determination of effect for differential rehabilitation protocols following initial ACL reconstruction and prior to return to sport. As nearly one-third of athletes who have a primary ACL injury and return to sport will experience a secondary injury, results from the proposed work will allow us to prospectively identify high risk patients who are the most appropriate recipients of enhanced treatment, including targeted training, which may reduce the risk of second ACL injury. Secondary ACL injury has the potential to end athletic careers, promote the development of osteoarthritis, and have debilitating effects on quality of life. Hence, the information gathered in this investigation will offer ACL injured athletes the optimal potential to reduce or potentially prevent these negative health effects before they are initiated.

The purpose of this study is to establish arthrogenic muscle inhibition (AMI) as a neural mechanism by examining the bilateral neuromotor drive of thigh musculature from AMI progression after anterior cruciate ligament (ACL) injury. The study will also determine the inhibitory effect of aberrant proprioceptive afferents on quadriceps and hamstring motor output. Furthermore, this study will determine the efficacy of neurofeedback to induce central changes that provide peripheral benefits to muscle activation.

The objective of this study is to investigate the clinical utility of the mi-eye 2™ device. This will be done by measuring the frequency with which the MRI and mi-eye 2™, respectively, change the Investigator’s primary diagnosis, confidence in diagnosis and management plan, in a routine clinical setting.

The purpose of this study is to compare the clinical results from knee  reconstruction surgery with an irradiated versus a non-irradiated ligament graft.

The purpose of this study is to better understand the mechanisms that can cause knee osteoarthritis (OA) following anterior cruciate ligament (ACL) rupture and ACL reconstruction (ACLR). Those who suffer an ACL injury have a dramatically increased risk of developing early onset knee OA compared to those who do not injure their ACL. While research has established a causal link between ACL injury and OA, the mechanism behind it is still unclear.

Aim 1 of this project will be entirely cadaveric and, thus, classified as not-human-subjects research by the Mayo Clinic IRB. Eight fresh-frozen cadaveric lower extremities (no history of knee trauma; < 50 years of age) will be acquired from a vendor that has provided >50 specimens with similar criteria in the past three years.5 Specimens will be thawed 24 hours prior to testing. 3D musculoskeletal (MSK) US images of the ACL in the intact knee will be acquired with an Aixplorer Mach 30 (SuperSonic Imagine, Bothell, WA). Literature described imaging techniques from both the anterior and posterior aspect of the knee will be used. SWE stiffness of the ACL will be calculated from the obtained images for cross-correlation against mechanical failure properties. Once images have been collected, each specimen will be resected such that the bone-ACL-bone complex remains intact. These complexes will be individually secured into custom mechanical fixtures and placed into a uniaxial hydraulic tensioner (MTS Systems, Eden Prairie, MN). Each structure will be exposed to 50 stress/relaxation cycles that vary ligament tension from 0-3% to remove viscoelastic effects. Specimens will then be tensioned at 20%/sec until failure is achieved. During tensioning, the hydraulic tensioner will measure displacement and a uniaxial load cell mounted to the tensioner will record linear force enacted on the tissue. ACL strain will be calculated as the linear displacement divided by the neutral ligament length (longest distance between ACL origin and insertion where the load cell registers 0 N force). Linear regression models will determine the significance of association between failure properties (ultimate strain, stress, and tensile strength) and US stiffness.

            For Aim 2, 40 total lower extremities will be recruited for 3D US imaging of the ACL at their pre-surgical clinical visit. This will include the injured limb from 20 pre-surgical patients with an MRI-confirmed ACL rupture and 20 healthy control limbs with no documented history of injury or scheduled surgery. Subjects recruited for the injured limb cohort may be dual-recruited as controls so long as their contralateral limb satisfies the inclusion criteria. US images will be acquired from both the anterior and posterior aspect of each knee. Injured versus control status will be documented by the collecting research team member. These images will be assessed and descriptively categorized by a separate, blinded, experienced rater for tear presence, location, severity, and type. For injured limbs, the clinical MRI for each subject will be acquired and similarly categorized. For healthy limbs, a research MRI will be scheduled and similarly categorized. Chi-Square test of independence will be used to assess statistical correlation between the US and MRI image classification. Receiver operator curves will be used to assess sensitivity and specificity of US and MRI diagnoses of ACL injuries against known clinical conditions.

Aim 1 of this project will be entirely cadaveric and, thus, classified as not-human-subjects research by the Mayo Clinic IRB. Eight fresh-frozen cadaveric lower extremities (no history of knee trauma; < 50 years of age) will be acquired from a vendor that has provided >50 specimens with similar criteria in the past three years.5 Specimens will be thawed 24 hours prior to testing. 3D musculoskeletal (MSK) US images of the ACL in the intact knee will be acquired with an Aixplorer Mach 30 (SuperSonic Imagine, Bothell, WA). Literature described imaging techniques from both the anterior and posterior aspect of the knee will be used. SWE stiffness of the ACL will be calculated from the obtained images for cross-correlation against mechanical failure properties. Once images have been collected, each specimen will be resected such that the bone-ACL-bone complex remains intact. These complexes will be individually secured into custom mechanical fixtures and placed into a uniaxial hydraulic tensioner (MTS Systems, Eden Prairie, MN). Each structure will be exposed to 50 stress/relaxation cycles that vary ligament tension from 0-3% to remove viscoelastic effects. Specimens will then be tensioned at 20%/sec until failure is achieved. During tensioning, the hydraulic tensioner will measure displacement and a uniaxial load cell mounted to the tensioner will record linear force enacted on the tissue. ACL strain will be calculated as the linear displacement divided by the neutral ligament length (longest distance between ACL origin and insertion where the load cell registers 0 N force). Linear regression models will determine the significance of association between failure properties (ultimate strain, stress, and tensile strength) and US stiffness.

            For Aim 2, 40 total lower extremities will be recruited for 3D US imaging of the ACL at their pre-surgical clinical visit. This will include the injured limb from 20 pre-surgical patients with an MRI-confirmed ACL rupture and 20 healthy control limbs with no documented history of injury or scheduled surgery. Subjects recruited for the injured limb cohort may be dual-recruited as controls so long as their contralateral limb satisfies the inclusion criteria. US images will be acquired from both the anterior and posterior aspect of each knee. Injured versus control status will be documented by the collecting research team member. These images will be assessed and descriptively categorized by a separate, blinded, experienced rater for tear presence, location, severity, and type. For injured limbs, the clinical MRI for each subject will be acquired and similarly categorized. For healthy limbs, a research MRI will be scheduled and similarly categorized. Chi-Square test of independence will be used to assess statistical correlation between the US and MRI image classification. Receiver operator curves will be used to assess sensitivity and specificity of US and MRI diagnoses of ACL injuries against known clinical conditions.