The anterior cruciate ligament (ACL) is a key structure in the knee, frequently injured during high-impact activities. This guide provides a detailed overview of ACL surgery, including its indications, procedure types, and recovery expectations.
What is the ACL?
The ACL is one of the four main ligaments in the knee joint, connecting the femur (thigh bone) to the tibia (shin bone). It stabilises the knee during movements involving sudden stops, pivots, or changes in direction. When the ACL is torn, knee stability can be compromised, leading to pain, instability, and difficulty with daily activities or sports. In severe cases, surgery is often required to restore proper knee function.
When Is ACL Surgery Needed?
ACL surgery may be necessary when non-surgical methods cannot adequately restore knee stability and function. Below are common scenarios where surgery is considered:
Knee instability during daily activities: Individuals experiencing frequent knee buckling or giving way during basic movements may require ACL surgery to restore stability. Persistent instability can increase the risk of secondary injuries to the meniscus or cartilage.
Returning to high-impact sports: Athletes or individuals engaged in activities involving jumping, pivoting, or sudden changes in direction often need surgical reconstruction to regain full functionality and reduce the likelihood of further injury.
Recurrent or severe ACL tears: In cases of repeated tears or injuries involving additional structures in the knee, surgery may provide a long-term solution compared to conservative management.
Types of ACL Surgery
ACL surgery involves different approaches and graft options. The choice depends on the extent of the injury and patient-specific factors.
ACL reconstruction vs ACL repair
Reconstruction replaces the damaged ligament with a graft, while repair involves reattaching the existing ligament. Reconstruction is more commonly performed, especially for severe or chronic tears, due to its higher success rate.
Autografts (tissue from your body)
Autografts are commonly taken from the patellar tendon, hamstring tendon, or quadriceps tendon. These grafts are strong and well-suited for ACL reconstruction, though recovery may take longer due to donor site healing.
Allografts (donor tissue)
Allografts are sourced from cadaver tissue and avoid the need for a secondary incision to extract graft material. They are convenient but may carry a slightly higher risk of infection or slower integration into the knee.
Preparing for ACL Surgery
Preparing for ACL surgery involves steps to optimise knee health and ensure a smoother recovery. Below are key aspects of preparation:
Physical Examination
A physical examination assesses knee stability, range of motion, and any swelling or tenderness. Specific manoeuvres, such as the Lachman test or pivot shift test, are used to evaluate the integrity of the ACL. The findings from the examination complement imaging results to provide a complete picture of the injury.
Imaging: MRI and X-Ray
Imaging techniques such as MRI and X-rays are used to confirm the diagnosis and assess the extent of the ACL injury. These scans provide detailed views of the ligament and surrounding structures, including the meniscus and cartilage. This information helps the surgeon determine the severity of the damage and plan the surgical approach.
Pre-Operative Requirements
Patients may need blood tests and other screenings to assess fitness for surgery. These tests help detect any health conditions that may affect the procedure. Current medications should be reviewed, and any that increase bleeding risks, such as blood thinners, may need to be paused temporarily.
What Happens During ACL Surgery?
ACL surgery involves several steps to ensure the graft is properly positioned, secured, and able to integrate with the surrounding tissue. Below is an overview of the key steps in the procedure:
Cleaning and Preparing the Joint
Before reconstructing the ACL, the surgeon removes the damaged ligament remnants and any loose cartilage or debris from the joint. This creates a clean surgical field and prevents interference with the placement and integration of the graft.
Arthroscopic Assessment
A small camera (arthroscope) is inserted through a small incision into the knee joint to assess the extent of the ACL tear and evaluate associated structures such as the meniscus or cartilage. This detailed view helps the surgeon plan the graft placement and address any additional injuries.
Graft Preparation and Placement
The chosen graft, whether autograft or allograft, is trimmed and prepared to match the specific dimensions of the knee. Tunnels are drilled in the femur and tibia to anchor the graft in the correct anatomical position.
Securing the Graft in Place
The graft is secured within the tunnels using screws or other fixation devices to ensure stability. The surgeon tests the graft’s tension and alignment to confirm it replicates the natural ligament’s function, balancing stability and mobility.
Final Checks and Closing the Incisions
After securing the graft, the surgeon re-inspects the joint to ensure proper placement and functionality. The incisions are then closed with sutures, and the knee is bandaged to minimise swelling and protect the surgical site.
Recovering After ACL Surgery
Recovery from ACL surgery requires a structured rehabilitation plan to restore knee function and prevent complications. Key aspects include:
Initial Post-Operative Care
Crutches and a knee brace are typically used to limit movement and protect the graft during the initial recovery period. Pain is managed with prescribed medications and cold therapy to reduce swelling and discomfort. Patients are encouraged to elevate the leg to decrease swelling and prevent stiffness. Follow-up appointments are scheduled to monitor the healing process and adjust care as needed.
Recovery Timeline
Recovery from ACL surgery occurs in phases, each targeting specific goals. During the first six weeks, the focus is on protecting the graft, reducing swelling, and regaining basic range of motion through gentle exercises.
From six to twelve weeks, muscle strengthening begins, and weight-bearing gradually increases. By three to six months, advanced exercises and sports-specific training prepare the knee for high-impact activities and full functionality.
Potential Risks and Complications
ACL surgery carries some risks, though these are uncommon. Surgical risks include infection, bleeding, and anaesthetic reactions, which are managed with appropriate care. Graft failure or loosening can occur if the graft does not integrate properly and may require further surgery.
Stiffness or reduced motion may result from scar tissue or inadequate rehabilitation but can often be improved with physiotherapy. ACL injuries, even after surgery, may increase the risk of osteoarthritis in the knee over time.
Preventing Future ACL Injuries
Preventing future ACL injuries involves maintaining strong and balanced muscles around the knee, particularly the quadriceps and hamstrings. Regular physiotherapy or exercise programmes focused on strength, flexibility, and proper movement techniques can help stabilise the joint. Using proper footwear and avoiding abrupt, high-risk movements during physical activity also reduces the chance of re-injury.
Conclusion
ACL surgery is a reliable solution for restoring knee stability and function after severe ligament injuries. Most patients achieve positive long-term outcomes with proper preparation, a precise surgical approach, and dedicated rehabilitation.
Schedule a consultation today to learn how ACL surgery can help you regain knee stability and mobility.
