Tunnel Widening in Augmented ACL Integration Via PrP Enriched Collected Autologous Bone vs Standard ACL Technique

A Single-center, Patient-blinded, Randomized, 2-year, Parallel-group, Superiority Study to Compare the Efficacy of Augmented ACL Integration Via Platelet-rich-plasma Enriched Collected Autologous Bone Versus Standard ACL Technique

The purpose of this clinical study is to compare the outcomes of two surgical techniques for reconstruction of the anterior cruciate ligament (ACL) after a single, primary ACL rupture.

The main question to be answered is:

- Does less widening of the tibial tunnel occur when a bone/Platelet rich plasma (PrP) composite material is placed directly into the tibial tunnel after fixation of the implant (experimental group) compared to the same surgery without the use of the composite material (control group)?

Participants will be randomized into one of the two groups and they will not know which group they belong to. After 12 months they will undergo CT, MRI, medical examination and functional knee testing. They will have a further medical examination and functional knee testing at 24 months. Patient Reported Outcomes will be collected before surgery, 6, 12 and 24 months after surgery.

To be successful, an ACL reconstruction requires a strong incorporation of the tendon to the bone within or at the margin of the tunnel, but the tunnel itself is at risk of widening, therefore compromising the tendon attachment. A composite of harvested healthy autologous bone fragments from the tunnel and autologous thrombin and fibrin, generated from the patient's PrP could be used at the interface between tunnel and ACL graft at the tibia and femur to reduce frequency of tunnel widening and therefore improve graft-bone-integration.

The study seeks primarily to determine less tibial tunnel widening when a bone/PrP-composite is applied directly in the tibial tunnel compared to the same surgery without using the composite, measured with CT and MRI.

Secondary study objectives are to evaluate femoral tunnel widening, tibial and femoral graft incorporation, graft maturation and knee function (clinical, functional, patient reported) over the course of 24 months follow-up and to evaluate occurrence of procedure- and product-related adverse events and complications.

This is a prospective, single-center, single-blinded, 2-arm-parallel, randomized, controlled study with 24 months follow-up. Participants will be recruited from the Knee Surgery department at Schulthess Klinik when scheduled for ACL reconstruction. The study sample comprises 107 patients, allocated 1:1 on experimental and control arm. Outcome measures are taken at 0, 6, 12, and 24 months. The total study duration is 48 months. The study duration per patient is 24 months.

Inclusion Criteria:

• Age 18-50 years
• Primary ACL rupture
• Time from injury to surgery: 4 weeks to 6 months
• Single ACL rupture (isolated rupture)
• ACL surgery with one of the participating senior surgeons
• Informed Consent as documented by signature

Exclusion Criteria:

• Concomitant ligamentous instability/rupture
• Requirement for Meniscus suture (partial resection accepted, hoop and roots remain intact)
• Requirement for cartilage invasive treatment (debridement accepted)
• Osteoarthritis at index knee joint
• Leg axis deviation over 3° valgus or 4° varus
• Claustrophobia (contra-indication for the MRI)
• Women who are pregnant or breast feeding or intention to become pregnant during the study
• Known or suspected non-compliance, drug or alcohol abuse
• Inability of the patient to follow the study procedures, e.g. language problems, psychological disorders, dementia, etc.