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

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Cruciate Ligament Rupture; Cruciate Ligament Reconstruction; Cruciate Ligament Injury
• Intervention / Treatment: Procedure: ACL reconstruction

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 70
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Marin Glavčić, MD; Phone Number: Marin Glavčić , MD +385 1; Email: mglavcic@kbd.hr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Standard ACL Reconstruction (Control Group); Standard all-inside ACL reconstruction with internal brace augmentation Patients undergo arthroscopic all-inside ACL reconstruction using a quadrupled semitendinosus tendon autograft. The graft is prepared using standard techniques. Fixation is achieved using suspensory fixation devices and internal brace augmentation. No biological augmentation is applied.	Procedure: ACL reconstruction; Participants will undergo arthroscopic all-inside anterior cruciate ligament reconstruction using an autologous semitendinosus graft. In the experimental intervention, a biologically augmented graft is used, including preservation of muscle tissue on the tendon (candy stripe technique) and application of autologous cancellous bone combined with platelet-rich fibrin at the graft-bone interface. In the control intervention, a standard tendon-only graft is used without biological augmentation. In both groups, graft configuration, tunnel creation, fixation technique, and surgical protocol are identical, and all procedures are performed by the same surgeon.
Active Comparator: Biologically Augmented ACL Reconstruction (Experimental Group); Biologically augmented all-inside ACL reconstruction Patients undergo arthroscopic all-inside ACL reconstruction using a semitendinosus tendon autograft with biological augmentation. The procedure includes: Preservation of a thin layer of muscle tissue on the tendon graft (candy stripe technique) Collection of autologous cancellous bone during tunnel drilling Preparation of autologous platelet-rich fibrin (PRF) from peripheral blood Creation of a composite graft using autologous bone mixed with fibrin glue Application of the biological composite material into femoral and tibial sockets to enhance graft integration Fixation is performed using standard suspensory devices consistent with the control group.	Procedure: ACL reconstruction; Participants will undergo arthroscopic all-inside anterior cruciate ligament reconstruction using an autologous semitendinosus graft. In the experimental intervention, a biologically augmented graft is used, including preservation of muscle tissue on the tendon (candy stripe technique) and application of autologous cancellous bone combined with platelet-rich fibrin at the graft-bone interface. In the control intervention, a standard tendon-only graft is used without biological augmentation. In both groups, graft configuration, tunnel creation, fixation technique, and surgical protocol are identical, and all procedures are performed by the same surgeon.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SNQ	To analyze and compare T2 signal-to-noise ratio values on magnetic resonance imaging at 6 weeks, 6 and 12 months postoperatively within and between the two study groups. The SNQ is calculated as the ratio of the graft T2 signal intensity to the signal intensity of a reference tissue on MRI. Higher SNQ values indicate higher graft signal, which corresponds to lower graft maturity/quality. Scale: Continuous numerical value (exact values depend on MRI signal calibration).	6 weeks, 6 and 12 months postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Bone Tunnel Diameter	The diameter of the femoral and tibial bone tunnel measured on MRI at 6 and 12 months postoperatively compared to the intraoperatively drilled diameter. Units: Millimeters (mm) Directionality: Higher values indicate tunnel widening	6 and 12 months postoperatively
Knee Stability - Anterior Tibial Translation	The anterior-posterior stability of the operated knee measured with the Lachmeter device at 12 months postoperatively. Units: Millimeters (mm) of anterior tibial translation Directionality: Higher values indicate greater laxity (worse stability)	12 months postoperatively
KOOS - Pain Subscale	Knee Injury and Osteoarthritis Outcome Score (KOOS) - Pain subscale, assessing knee pain. Scale: 0-100 (0 = extreme pain, 100 = no pain; higher scores = better outcome)	Before surgery, 6 weeks, 6 months, 12 months postoperatively
KOOS - Symptoms Subscale	KOOS - Symptoms subscale, assessing knee symptoms (e.g., swelling, stiffness). Scale: 0-100 (0 = severe symptoms, 100 = no symptoms; higher scores = better outcome)	Before surgery, 6 weeks, 6 months, 12 months postoperatively
KOOS - Activities of Daily Living (ADL) Subscale	KOOS - ADL subscale, assessing functional ability in daily activities. Scale: 0-100 (0 = extreme limitation, 100 = no limitation; higher scores = better outcome)	Before surgery, 6 weeks, 6 months, 12 months postoperatively
KOOS - Sports/Recreation Subscale	KOOS - Sports/Recreation subscale, assessing function during sport or recreational activity. Scale: 0-100 (0 = extreme limitation, 100 = no limitation; higher scores = better outcome)	Before surgery, 6 weeks, 6 months, 12 months postoperatively
KOOS - Quality of Life (QoL) Subscale	KOOS - QoL subscale, assessing knee-related quality of life. Scale: 0-100 (0 = extreme problem, 100 = no problem; higher scores = better outcome)	Before surgery, 6 weeks, 6 months, 12 months postoperatively
KDC-SKF (International Knee Documentation Committee - Subjective Knee Form)	Patient-reported measure of knee function, symptoms, and sports activity. Scale: 0-100 (0 = worst knee function, 100 = best knee function; higher scores = better outcome)	Before surgery, 6 weeks, 6 months, 12 months postoperatively
Rerupture rate	Rates of reruptures of ACL graft in operated patients	1 year, 2 years and 5 years postoperatively

Collaborators and Investigators

• Sponsor: University Hospital Dubrava
• Collaborators: Arthrex GmbH

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2032

Study Registration Dates

• First Submitted: March 26, 2026
• First Submitted That Met QC Criteria: March 26, 2026
• First Posted (Actual): April 1, 2026

Study Record Updates

• Last Update Posted (Actual): April 16, 2026
• Last Update Submitted That Met QC Criteria: April 13, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Anterior Cruciate Ligament; Knee; Arthroscopy; Tissue Remodeling; Semitendinosus Muscle
• Other Study ID Numbers: 024/0719-3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No