Influence of the Different Types of Tibial Fixation in the Reconstruction of the Anterior Cruciate Ligament of the Knee: Osseous Integration, Ligament Maturation and Clinical Results.

Influence of different tibial fixation methods in anterior cruciate ligament (ACL) reconstruction: bone integration, graft maturation, and clinical outcomes.

Primary Objective

To assess whether any of the four tibial fixation techniques is superior in terms of:

Graft-bone integration (CT/MRI),

Graft maturation (MRI),

Clinical outcomes (IKDC, Lysholm, Tegner scores; manual and instrumented knee stability with KT-1000 arthrometer).

Secondary Objectives

Compare clinical outcomes among groups (IKDC, Lysholm, Tegner).

Compare re-rupture rates and patient satisfaction.

Study Design

Prospective randomized trial.

The study will be registered in the international Clinical Trials registry.

Inclusion Criteria

Age ≥18 years.

Complete ACL rupture treated with arthroscopic ACL reconstruction using autologous hamstring tendons.

Exclusion Criteria

Age ≥55 years.

Patients treated with allografts, bone-patellar tendon-bone grafts, or quadriceps tendon grafts.

Malpositioned tunnels (evaluated by MRI at 6 months postop).

Previous knee surgery.

Femoral or tibial deformities.

Multiligament injuries.

Note: Soft tissue procedures (e.g., meniscal repair) are not exclusion criteria.

Randomization

Patients meeting inclusion/exclusion criteria will be randomized (via Research Randomizer: https://www.randomizer.org/

) into 3 groups:

Group A (TORN): bioabsorbable interference screw, same diameter as the tunnel.

Group B (TORN+1): bioabsorbable interference screw, one mm larger than the tunnel diameter.

Group C (TORN-BT): interference screw (same size as tunnel) + second fixation with cortical button/plate.

Sample size: 37 patients per group, 111 total.

Follow-up

Radiographic, CT, and MRI evaluation pre-op, at 15 days, and at 1 year post-op.

Clinical and radiological follow-up for 1 year.

Statistical Analysis

In the prospective phase, Student's t-test will be performed for comparison of pre- and postoperative variables. All variables will also be compared between groups and within groups (baseline vs. end of follow-up) using analysis of variance (ANOVA).

Linear regression models will be applied to test for potential significance that could be masked by confounding factors.