The goal of this clinical trial is to learn if using a phone app for exercises is as effective as working with a physical therapist before anterior cruciate ligament knee surgery. It will also check if exercising before surgery helps patients recover better compared to those who do not follow a specific exercise plan. The main questions it aims to answer are:

• Does the phone app help patients improve their knee strength and movement as well as seeing a physical therapist?
• Do patients who exercise before surgery have a better recovery after surgery than those who do not?

Researchers will compare the phone app group to a physical therapist group and a group with no specific exercise plan to see which method works best.

Participants will:

• Follow an exercise plan for 4 weeks before their surgery (either using the app, with a therapist, or no specific plan).
• Visit the clinic for check-ups before starting the exercises, right before the surgery, and 6 months after the surgery.
• Complete simple tests and surveys to measure their knee health.

This study is a prospective randomized controlled trial designed to investigate the effects of different preoperative rehabilitation methods on patients scheduled for Anterior Cruciate Ligament (ACL) reconstruction.

Participants will be stratified based on their injury type (Isolated ACL injury vs. ACL injury with concomitant meniscus tear) to ensure homogenous distribution. Following stratification, patients will be randomized into three parallel groups using a computer-generated block randomization method (block size of 6).

The study consists of three phases:

1. Pre-operative Intervention (4 Weeks):

   • Video Based Mobile Application Group (Unsupervised): Participants will follow a progressive exercise program via a mobile app. The app provides asynchronous video guidance, reminders, and compliance tracking. The program focuses on range of motion, edema reduction, and muscle strengthening.
   • Supervised Rehabilitation Group: Participants will undergo the exact same exercise protocol under the direct supervision of a physiotherapist (3 sessions/week) in a clinical setting.
   • Control Group: Participants will receive standard care without a specific structured exercise prescription.

2. Surgical Intervention:

   All participants will undergo ACL reconstruction surgery performed by the same surgical team using hamstring autografts.

3. Post-operative Rehabilitation:

Following surgery, ALL patients in all three groups will receive the same standardized, goal based postoperative rehabilitation program. This protocol is based on international criteria and aims to ensure that postoperative care is consistent across all groups, isolating the effect of the preoperative intervention.

Outcomes will be assessed at baseline, preoperatively (after the 4 week program), and 6 months postoperatively. Key assessment methods include:

• Isometric muscle strength testing (Quadriceps and Hamstring) using a hand-held dynamometer.
• Functional performance assessment via Single Leg Hop Tests (limb symmetry index).
• Proprioception evaluation using active joint position sense tests.
• Knee range of motion measurement with a electronic goniometer.
• Patient-reported outcomes using the IKDC 2000 Subjective Knee Evaluation Form.

The primary objective is to determine if the unsupervised digital model is non-inferior to supervised rehabilitation in improving functional outcomes.

Inclusion Criteria:

• Patients with a diagnosed unilateral Anterior Cruciate Ligament (ACL) rupture
• Patients scheduled for ACL reconstruction surgery.
• Age between 18 and 45 years.
• Patients willing to participate and sign the informed consent form.

Exclusion Criteria:

• Patients with multiple ligament injuries (e.g., combined ACL and PCL/MCL injury).
• Patients with bilateral ACL injuries.
• Presence of accompanying fractures around the knee joint.
• Presence of active infection.
• Patients who refuse surgery or withdraw consent.