Anterior Cruciate Ligament Injury or ACL tear is one of the most common types of knee injury seen in not only athletes but anyone of any age. This injury usually results from a sports injury as it is not easy to break the ACL because it is one of the strongest ligaments of the knee that not only stabilizes it but prevents it from anterior translation as its name suggests. 

When it breaks people often hear a popping sound that indicates the tear. The bones get unstable and often rub together that can create cracking sound as well. Knee becomes unstable and the pain that follows is very unbearable.

Sign & Symptoms 

• Popping sound when it breaks
• Unstable knee
• Unbearable pain in the knee
• Redness around the joint
• Swelling 
• Tenderness
• Loss of range of motion 
• Inability to stand still with loads on knee

Grades Of Tear

1. First Grade: It is the grade of mild injury where a few fibres of the ligament are torn, the pain, swelling and redness is comparatively not that unbearable. It can be easily managed with conservative treatment such as RICE.
2. Second Grade: It is the grade of partial or moderate tear where about half of the ACL tears away. This is comparatively more severe than the first grade. The pain, swelling, redness and instability is quite unbearable and it can also be managed by conservative treatment.
3. Third Grade: It is the grade of complete tear. The entire ligament breaks into two. Symptoms can be worse and it’s not manageable with conservative treatment. Surgery is often suggested in this grade.

Causes 

• Often happens in sports Injuries
• Suddenly slowing down from running 
• Quickly changing direction in speed 
• Landing awkwardly on the ground from high jumps
• Direct blow on the anterior side
• Road Traffic Accidents
• Faulty biomechanics during gym or exercises

Management 

The management of the ACL injury often varies based upon the grade of severity it lies in. If it is third grade, the surgery is the only option, rest of the post operative treatment can be managed with physiotherapy. However, some conservative treatment came be helpful in first two grades such as:

• Cryotherapy or cold therapy for reducing swelling and redness 
• Rest is mandatory to prevent it from further tear
• Some anti-inflammatory drugs can be suggested i.e. NSAIDs 
• Supportive braces and bandages for immobilization
• Walking aids for supportive standing

Physiotherapy Management 

ACL Rehabilitation Overview

ACL rehabilitation is typically divided into phases  with specific goals and exercises best suitable for the patients. The progression through these phases depends on individual recovery and whether the treatment is surgical or conservative.

Phases of ACL Rehabilitation

1. Prehabilitation (Pre-surgical Phase)
   1. Goals:
      1. Reduce swelling and inflammation
      2. Restore range of motion (ROM)
      3. Strengthen surrounding muscles
   2. Exercises:
      1. Isometric quadriceps contractions
      2. Straight leg raises
      3. Heel slides
      4. Stationary cycling
2. Phase 1: Acute Post-operative Phase (Weeks 0–2)
   1. Goals:
      1. Protect the surgical site
      2. Control pain and swelling
      3. Knee extension and at least 90° flexion
      4. Initiate muscle activation
   2. Interventions:
      1. Use of cryotherapy
      2. Neuromuscular electrical stimulation (NMES)
      3. Gentle ROM exercises
      4. Partial weight-bearing with assistive devices
3. Phase 2: Early Rehabilitation Phase (Weeks 2–6)
   1. Goals:
      1. Improve ROM
      2. Increase weight-bearing capacity
      3. Enhance muscle strength
   2. Exercises:
      1. Closed kinetic chain exercises (e.g., mini squats)
      2. Leg presses
      3. Step-ups
      4. Balance and proprioception training
4. Phase 3: Intermediate Rehabilitation Phase (Weeks 6–12)
   1. Goals:
      1. Restore full ROM
      2. Improve muscular strength and endurance
      3. Enhance neuromuscular control
   2. Exercises:
      1. Lunges
      2. Single-leg squats
      3. Plyometric drills
      4. Agility exercises
5. Phase 4: Advanced Rehabilitation Phase (Months 3–6)
   1. Goals:
      1. Prepare for return to sport
      2. Ensure dynamic knee stability
      3. Achieve symmetrical strength and function
   2. Exercises:
      1. Sport-specific drills
      2. Cutting and pivoting maneuvers
      3. Jumping and landing techniques
6. Phase 5: Return to Field  Phase (After 6 Months)
   1. Criteria for Return:
      1. No pain or swelling
      2. Full ROM
      3. Strength and functional tests 
      4. Psychological readiness