The anterior and posterior cruciate ligaments allow for flexion and extension of the knee. Tears of these ligaments are a common result of sudden movements that cause strain. Injury can occur from sudden stops or from trauma to the knee as a result of sports activities. When the tear is severe, surgery is often needed. Rehabilitation and exercises to retain mobility of the joint and to preserver strength prior to surgery. After surgery, the recovery process follows a distinctive set of steps.
Anterior Cruciate Ligament Tears and Repairs

Introduction

Tears of the anterior and posterior cruciate ligaments are a common knee injury that affect people of all ages and activity levels. The injury can range from minor to severe, depending on the extent of the tearing. Some, but not all require surgery to restore range of motion to affected joint. The injury often requires extensive rehabilitation to regain function. The following explore the cycle of this injury further.

Physiology of the Injury

The knee consists of the intersection of three bones, the femur, tibia, and patella. The patella sits in front of the joint to provide protection to the soft tissues. Ligaments connect these bones and keep the knee stable. The cruciate ligaments are located on the inside of the knee joint. They form an X with the anterior cruciate ligament in the front and the posterior cruciate ligament in the back. These ligaments allow for the extension and flexion of the knee (OrthoInfo, 2019). A tear to these ligaments disrupts the ability to move the knee and can affect the ability to walk.

An injury to these ligaments can have an effect on the normal homeostasis of the body by reducing the ability to move the knee in the full range of motion and can interfere with stability when standing and with mobility (OrthoInfo, 2019). The injury will also activate the inflammatory and potentially the immune response. The injury can also have an impact on the body if the pain causes the person to lose sleep or be unable to perform daily activities. Pain from the injury can be a source of stress and activate the cortisol response. In addition, compensating for the injury can cause strain or damage to other joints in the body. The injury can have an impact on the overall health of the person and affect the body beyond the ability to move the knee.

The impact of the injury on the body depends on the grade of the injury. They are classified into Grade 1 sprains, which are mildly damaged ligaments that have been slightly stretched. Grade 2 sprains are where the ligament has been stretched to the point where it becomes loose and may have a partial tear (OrthoInfo, 2019). A Grade 3 sprain is where a complete tear of the ligament has occurred (OrthoInfo, 2019). The knee is unstable with a grade 3 strain and will typically require surgery to repair.

Etiology

The most common cause of a cruciate ligament tear is changing direction rapidly or stopping suddenly. It can also be caused by suddenly slowing down while running or landing incorrectly while jumping (OrthoInfo, 2019). One of the most common causes of a cruciate ligament tear is from impact due to contact sports such as football, soccer, or baseball (OrthoInfo, 2019). Improper alignment of the joint when bearing weight can cause a ligament strain or tear.

Female athletes have a tendency to experience ACL tears more frequently than males. It has been proposed that this is due to different in muscular strength and neuromuscular control (OrthoInfo, 2019). It has also been suggested that estrogen creates increased looseness in the ligaments, which increases the risk for injury (OrthoInfo, 2019). Regardless of age, physical conditioning and attention to proper alignment when performing any type of task will help to prevent damage to the knee joints and tissues.

Signs and Symptoms

When a cruciate ligament tear occurs, the symptoms are sudden and noticeable. The person may hear a pop and the knee may give out. There will also be pain and swelling at the injury site. The swelling will increase over the next 24 hours. The person typically loses range of motion and there is tenderness in the joint. The person may experience pain while walking, or when moving from sitting to standing. The pain and swelling may resolve in 24 hours, but returning to full activity runs the risk of further injury, possible damaging the meniscus (OrthoInfo, 2019).

Diagnosis of the injury includes a physical examination of the structures of the injured knee and imaging tests which may include an MRI. X-rays will sometimes be performed to determine if there has been damage to the surrounding bone (OrthoInfo, 2019). This is especially the case if the injury occurred in connection to a fall or impact. An MRI can help visualize the soft tissues, such as the cruciate ligament and is more useful for diagnostic purposes than an X-ray, in most cases.

Treatment and Return to Function

Several factors affect the speed of healing the return to full function. The first is the level of physical activity that is desired. The time it...…set of exercises works the major muscle groups and is relatively safe with various degrees of injury. These exercises are recommended prior to surgery, but they are also used as the next phase of rehab, if physical therapy will be used without surgery.

Type of Surgery

ACL repair involves using a graft to replace the torn ligament. Graphs are typically from the person’s own body. The most common tendons used are the patellar tendon or one of the hamstring tendons (Healthlink BC, 2015). Sometimes the graft is taken from a deceased donor (Healthlink BC, 2015). In some cases, a piece of the bone is also separated and must be reattached during surgery (Healthlink BC, 2015). In most cases, the surgery can be done arteroscopically with only a few small incisions (Healthlink BC, 2015).

Post-surgery Protocols with Rehab Exercises

Many persons who undergo surgery for repair of the cruciate ligament are under the misconception that because it is usually possible to go home the same day as surgery, that the recovery process will be easy and fast (UMPC Orthopaedic Care, 2015). However, regardless of how long one must stay in the hospital, the recovery process to full functionality is a long process. Full recovery can take between 2 to 9 months post-surgery (UMPC Orthopaedic Care, 2015).

In the first two weeks after surgery, no weight bearing will be allowed. Crutches are typically required for the first four weeks after surgery (UMPC Orthopaedic Care, 2015). Sometimes, a passive motion machine is used that provides movement without relying on the knee muscles. Resting and caring for the incision site is a priority in the first few weeks (UMPC Orthopaedic Care, 2015).

In 2-4 weeks weight bearing will begin and physical therapy is typically 2-3 times per week. In weeks 2-9, the difficulty of the physical therapy increases with the goal of returning to regular physical activity (UMPC Orthopaedic Care, 2015). The individual goals of the patient will determine the intensity and length of the physical therapy after surgery (UMPC Orthopaedic Care, 2015).

Conclusion

A tear of the anterior and/or posterior cruciate ligament is a common injury caused by overexertion or trauma to the knee. The length of recovery time and whether it requires surgery depends on the grade of the injury. This injury requires a long healing process, even for minor injuries. If surgery is needed, a graft is taken from another portion of the body, in most cases. The rehabilitation process focuses on regaining strength, while avoiding reinjury. Full recovery is a long process, depending on the degree of strength and activity level…