Anterior Cruciate Ligament (ACL) Injury

Anterior cruciate ligament (ACL) is one of the major knee ligaments that connect the thigh bone (femur) to the shin bone (tibia).  The ACL is essential for maintaining proper knee function and knee stability by preventing excessive forward movement. It is also important for various activities that involve sudden stops, changes in direction, or pivoting.

Injury to the ACL leads to knee instability, swelling, and difficulty with weight-bearing activities, commonly resulting from sudden stops, pivots, or impacts during sports or accidents.

Cuban orhopaedic surgeons are highly experienced in accurately assesses the extent of ACL injury and providing the most effective treatment plan. For this knee condition, treatment options in Cuba may include non-surgical methods like physical therapy to strengthen the surrounding muscles and improve stability, or surgical reconstruction to repair or replace the torn ligament.

If an ACL injury is left untreated, several complications can arise including:

• Chronic knee instability.
• Increased risk of additional injuries, including damage to other knee ligaments.
• Early-onset osteoarthritis.
• Muscle weakness and atrophy.
• Reduced quality of life.

Types of ACL Injuries

The Anterior Cruciate Ligament (ACL) can sustain various types of injuries, each differing in severity. ACL injuries are referred to as sprains and are classified by grade ranging from one (the least severe) to three (the most severe):

• Grade 1 Sprain: This is the mildest form of ACL injury, where the ligament is slightly stretched but not torn causing minimal instability in the knee.
• Grade 2 Sprain: In this type of injury, the ACL is partially torn resulting in moderate knee instability and pain.
• Grade 3 Sprain: This is the most severe type of ACL injury, where the ligament is completely torn or ruptured, leading to significant knee instability.

Causes of ACL Injuries

ACL injury can be the result of anything that puts too much force on the knee including:

• Sudden stops and sudden changes in direction.
• Landing awkwardly from a jump or incorrect landing techniques that do not distribute force evenly across the knee joint.
• Direct blow to the knee (commonly seen in contact sports).
• Overextension of the knee beyond its normal range of motion.
• Muscle weakness in the hamstrings or poor core strength.
• Insufficient training or improper warm-up routines before exercise.
• Anatomical factors, women are more prone to ACL injuries due to anatomical differences and hormonal fluctuations during the menstrual cycle.
• Environmental factors such as hard surfaces or wearing inappropriate footwear.
• Previous injuries, especially to the ACL, can weaken the ligament.
• Genetic factors and family history of ACL injuries can predispose individuals to similar injuries due to inherited anatomical or biomechanical traits.

Symptoms of ACL Injuries

An ACL injury can present with several symptoms that vary in intensity depending on the severity and extent of the injury:

• Sudden, severe and sharp pain typically centered in the knee joint.
  • Audible popping sound accompanied by immediate instability in the knee.
  • Swelling due to the accumulation of blood and fluid inside the joint (hemarthrosis).
  • Instability with a sense of the knee not being able to support the body’s weight properly.
  • Loss of range of motion
  • Touch sensitivity particularly along the joint line.
  • Visible discoloration around the knee due to bleeding within the joint.
  • Impaired functionality, difficulty walking and bearing weight.
  • Involuntary contractions or spasms of the muscles around the knee.

Diagnosis of ACL Injuries

Diagnosing an ACL injury begins with medical history and physical examination whereby a review of symptoms, history of injury, examination of the knee for structures integrity and comparing the injured knee to the non-injured knee. Other tests which may help confirm diagnosis include:

• X-Rays: While X-rays cannot visualize the ACL, they help rule out bone fractures and other injuries.
• Magnetic Resonance Imaging (MRI): MRI is typically used for diagnosing ACL injuries as it provides detailed images of soft tissues, including the ACL, menisci, and other ligaments. It can confirm the presence and extent of the tear.
• Computed tomography scan (CT): CT may be used if there are concerns about small bone fractures.

Treatment for ACL Injuries

Treatment for an ACL injury can vary depending on the severity of the injury and the patient’s activity level. For grade 1 and 2 injuries nonsurgical treatment such as bracing or physical therapy is most appropriate for a gradual progression back to regular activities. For more severe conditions, surgical treatment may be recommended.

Non-Surgical Treatment

• Bracing: This is a crucial part in the management of ACL injuries. Bracing provides support and stability to the knee joint by limiting the range of motion and movements that could cause further injury or strain. Bracing, especially when used with a structured physical therapy program, can significantly enhance the healing process, reduce the risk of re-injury, and support a safe return to normal activities.
• Physical therapy: Physical therapy is a key component in the treatment of ACL injuries, playing a vital role in both non-surgical and post-surgical recovery processes. It aims to restore function, improve strength, enhance flexibility, and prevent future injuries by guiding patients through a structured and progressive rehabilitation program. Included are:
  • Range of motion (ROM) exercises.
  • Quadriceps activation.
  • Strengthening exercises.
  • Weight-bearing activities.
  • Proprioception training exercises.
  • Patellar mobility.
  • Dynamic stability exercises.
  • Neuromuscular training.
  • Functional training.
  • Agility training.
  • Manual therapy.
  • Functional Electrical Stimulation (FES).

Surgical Treatment

Surgical treatment for an ACL injury, particularly in the case of a complete tear, involves reconstructing the ligament to restore stability and function to the knee. The decision to undergo surgery depends on several factors, including:

• Degree of knee instability.
• More than one ligament or the fibrous cartilage in your knee also is injured.
• The injury is causing the knee to buckle during everyday activities.
• Patient’s activity level.
• Patient’s age.

Physical therapy is often recommended prior to surgery to reduce swelling, restore knee range of motion, and strengthen surrounding muscles, to reach better post-surgical outcomes.

• ACL reconstruction: This is a knee arthroscopy (minimally invasive) surgical procedure that is carried out to replace a torn anterior cruciate ligament in the knee, that involves using tissue graft harvested from the patient’s own patellar tendon, hamstring tendon, or quadriceps tendon, or from a donor.

This procedure requires the drilling of a tunnel into the femur (thighbone) at the original attachment site of the ACL and a corresponding tunnel into the tibia (shinbone) also at the original attachment site of the ACL. The prepared graft is then threaded through the tunnels in the femur and tibia and is secured into place using screws, buttons, or other fixation devices to ensure it remains stable and properly positioned. The incisions are closed with sutures.

• ACL repair: This is a surgical procedure aimed at fixing a torn ACL, primarily by reattaching the ligament to the bone rather than replacing it with a graft, as is done in ACL reconstruction. This approach is less common and typically reserved for specific cases, such as young patients with avulsion fractures where the ligament is torn off with a piece of bone.

This is arthroscopic surgery in which small incisions are made around the knee. If the ACL has torn off with a piece of bone (avulsion fracture), the bone fragment is reattached to the femur or tibia using screws, sutures, or other fixation devices. In cases of partial tears or fresh injuries, the torn ends of the ligament are sutured back together and secured to the bone using anchors or sutures.

Postoperative physical therapy following ACL surgery is critical for a successful recovery and involves a structured, progressive rehabilitation program designed to restore knee function, strength, and stability.