Biological Potentials in Arthroscopic All-inside Semitendinosus Anterior Cruciate Ligament Reconstruction

A Double-blind, Randomized, Prospective, Single-center Study of Biological Potentials in Arthroscopic All-inside Semitendinosus Anterior Cruciate Ligament Reconstruction

A randomized, double-blind, prospective single-center clinical trial evaluating the effect of biological augmentation in anterior cruciate ligament (ACL) reconstruction. The study compares standard all-inside semitendinosus ACL reconstruction versus biologically enhanced reconstruction incorporating muscle tissue preservation and autologous bone and fibrin augmentation. The primary aim is to assess whether biological augmentation improves graft healing, integration, and clinical outcomes.

Anterior cruciate ligament (ACL) reconstruction outcomes depend on multiple factors including surgical technique, graft selection, fixation methods, and rehabilitation. Hamstring tendon autografts are commonly used due to favorable biomechanical properties and low donor-site morbidity. Traditionally, graft preparation involves complete removal of muscle tissue; however, emerging techniques such as the "candy stripe" method preserve residual muscle, which may provide a source of stem cells and enhance biological healing.

In addition, biological augmentation strategies-including the use of autologous bone graft and platelet-rich fibrin (PRF)-have been proposed to improve tendon-to-bone integration and accelerate ligamentization. These approaches aim to enhance graft incorporation, structural integrity, and overall functional recovery.

This study is a double-blind, randomized, prospective, single-center clinical trial including 70 patients with ACL rupture. Participants are randomly assigned into two groups (n=35 per group):

A control group undergoing standard all-inside ACL reconstruction. An intervention group undergoing biologically augmented ACL reconstruction.

All procedures are performed using an all-inside technique with semitendinosus tendon autografts. The biologically augmented group differs by:

Preservation of a thin layer of muscle tissue on the graft (candy stripe technique) Use of autologous cancellous bone collected during tunnel drilling Application of autologous fibrin glue (platelet-rich fibrin) combined with bone graft to enhance healing at graft-tunnel interfaces The primary objective is to evaluate whether biological augmentation improves graft healing and clinical outcomes compared to standard reconstruction.

Inclusion Criteria:

• Clinically and radiologically confirmed anterior cruciate ligament (ACL) rupture.
• Age between 18 and 50 years.
• Intact posterior cruciate ligament and collateral ligaments.
• Signed informed consent to participate in the study.
• Patients meeting at least one indication for concomitant lateral tenodesis, including: age under 25 years, positive pivot-shift test, presence of Segond fracture, participation in sports with frequent changes of direction and rotational knee loads, or joint hypermobility (Beighton score ≥ 7).

Exclusion Criteria:

• Previous ACL reconstruction of the same knee.
• Inability to use a graft prepared by quadruple folding of the semitendinosus tendon.
• Graft diameter < 7.5 mm.
• MRI-confirmed unsuccessful meniscal healing after repair.
• Acute joint infection or history of joint infection.