Arthroscopic ACL reconstruction is a minimally invasive surgery that uses a tendon graft (often from the patient’s own body or a donor) to reconstruct the torn anterior cruciate ligament (ACL). This surgery restores knee stability and function, particularly important for those who engage in sports or physical activities that require knee strength and flexibility.
The surgery itself is painless due to anaesthesia. Post-operative pain is expected but manageable with medication and physiotherapy.
This procedure is very effective for restoring stability and function to the knee. The success rate is high, especially when combined with a comprehensive post-operative physiotherapy program.
Recovery from arthroscopic ACL reconstruction varies depending on the individual’s age, general health, and commitment to rehabilitation. In most cases, it takes around six to twelve months to fully recover and return to normal activities or sports. The first few weeks after surgery focus on reducing swelling, managing pain, and regaining basic knee movement. Patients often use crutches for a short period and wear a knee brace for support. Physiotherapy usually begins soon after surgery and progresses gradually to include exercises that strengthen the quadriceps and hamstrings, improve balance, and restore flexibility. By around three months, most patients can resume light activities such as stationary cycling or swimming. Running and sport-specific drills are typically introduced between four and six months, depending on progress. Full return to pivoting or contact sports is generally allowed only after the surgeon and physiotherapist confirm that knee strength and stability have fully returned. Consistent physiotherapy, adherence to exercise programs, and avoiding early strain on the new graft are key factors in achieving the best outcome. While recovery is gradual, most patients regain excellent knee function and stability, allowing them to return confidently to their previous level of activity.
The timeline for returning to sports after arthroscopic ACL reconstruction varies between individuals, but it generally falls within six to twelve months after surgery. The exact timing depends on several factors, including how well the graft heals, the patient’s strength, balance, and confidence in the knee, as well as the type of sport they wish to return to. In the first few months, the focus is on restoring movement, reducing swelling, and rebuilding basic muscle control. Light activities such as stationary cycling or swimming are usually introduced around two to three months after surgery. Running and sport-specific training often begin between four and six months, once the knee shows good strength and stability. However, cutting, pivoting, and contact sports require a longer recovery period because these movements place significant stress on the reconstructed ligament. Before returning to competitive sports, patients undergo a series of functional tests to assess knee stability, strength, and agility. Only when the graft has fully matured, and both legs demonstrate comparable performance, is a safe return advised. This typically happens between nine and twelve months post-surgery. Returning too early increases the risk of re-injury, so careful guidance from the surgeon and physiotherapist is essential for a successful, long-term recovery.
In arthroscopic ACL reconstruction, the damaged ligament is replaced with a graft, which serves as a scaffold for new ligament tissue to grow. The most common graft options are autografts and allografts. An autograft is tissue taken from the patient’s own body, usually from the hamstring tendon, patellar tendon, or quadriceps tendon. The hamstring tendon graft is popular because it causes less discomfort at the donor site and provides excellent strength and flexibility. The patellar tendon graft, taken from the front of the knee, offers strong fixation and is often preferred for athletes involved in high-demand sports, although it can sometimes cause anterior knee pain. The quadriceps tendon graft is another reliable option, particularly for patients who have had previous surgeries or specific anatomical considerations. An allograft, on the other hand, comes from a donor and is used less frequently in younger or highly active patients due to slightly higher re-tear rates. However, it may be suitable for older adults or revision surgeries where donor-site pain needs to be avoided. The choice of graft is made after careful discussion between the patient and surgeon, considering factors such as age, activity level, surgical history, and personal preferences.
After arthroscopic ACL reconstruction, many patients are fitted with a knee brace for the early stages of recovery. The main purpose of the brace is to protect the new graft, provide stability, and prevent sudden movements that could strain the healing ligament. Typically, the brace is worn continuously for the first few weeks, especially when walking or sleeping, to keep the knee supported and to remind the patient to move carefully. As recovery progresses and muscle strength improves, the need for the brace gradually decreases. Most surgeons recommend discontinuing the brace around four to six weeks after surgery, depending on how stable the knee feels and how well the patient performs in physiotherapy. Some patients may continue wearing a functional sports brace for additional support during higher-risk activities, particularly when returning to running or pivoting sports. However, not all surgeons routinely use braces after ACL reconstruction. Advances in surgical techniques and rehabilitation protocols mean that some patients can safely recover without one, relying instead on physiotherapy and controlled movement. The decision ultimately depends on the individual’s knee stability, graft type, and the surgeon’s specific post-operative protocol. Dr Oliver Khoo tailors brace use to each patient’s unique recovery needs and lifestyle.
Recovery time after arthroscopic ACL reconstruction varies for each person but generally ranges from six to twelve months. The timeline depends on factors such as the type of graft used, the patient’s age, overall health, and commitment to rehabilitation. In the first few weeks, the focus is on reducing swelling, regaining knee movement, and restoring basic muscle control. Most patients can walk without crutches within two to four weeks, although this may vary depending on the surgeon’s advice and the individual’s progress. By around three months, patients usually achieve better strength and range of motion, allowing them to return to light, low-impact activities such as cycling or swimming. From four to six months, more intensive exercises are introduced to rebuild muscle endurance and improve knee stability. A return to running and sport-specific movements typically occurs during this period, guided closely by a physiotherapist. Full return to pivoting or contact sports generally happens between nine and twelve months, once the graft has fully integrated and the knee has regained strength and coordination. Rushing recovery can increase the risk of re-injury, so following the prescribed rehabilitation plan is crucial. With proper care and physiotherapy, most patients regain excellent knee function and long-term stability.
Most patients regain excellent knee function after arthroscopic ACL reconstruction, particularly when they follow a structured rehabilitation program and maintain consistency with physiotherapy. The goal of surgery is to restore the stability, strength, and movement of the knee so patients can return to their normal daily activities and even competitive sports. In the early recovery phase, stiffness and weakness are common, but these gradually improve as swelling settles and exercises are introduced to strengthen the muscles around the knee. By around three months, most patients notice significant improvements in walking, bending, and basic movements. Continued physiotherapy over the following months helps rebuild balance, coordination, and muscle control, all of which are essential for full recovery. Studies show that over 90 percent of patients regain near-normal or normal knee function within a year after surgery. However, achieving this outcome depends on several factors, including the patient’s age, overall health, graft type, and adherence to the rehabilitation plan. Some mild loss of flexibility or occasional discomfort may persist for a small number of patients, especially after high-impact activities, but these are usually manageable. With time, effort, and guidance from the surgical and physiotherapy team, most people return to their previous activity levels with stable, pain-free knees.
Return to sports after arthroscopic ACL reconstruction depends on several factors, including the type of graft used, the quality of rehabilitation, and how well the knee has healed and regained strength. In most cases, patients can expect to return to sports between 9 and 12 months after surgery. However, this timeline can vary significantly from person to person. The first few months after surgery focus on reducing swelling, restoring knee motion, and rebuilding muscle strength, particularly in the quadriceps and hamstrings. Around the three to six-month mark, exercises shift toward improving balance, agility, and sport-specific movement patterns. Before returning to competitive play, the patient must demonstrate good strength symmetry between both legs, excellent balance, and stable knee control during cutting, pivoting, and jumping tasks. Many surgeons and physiotherapists now use functional testing to guide clearance for return to sport rather than relying solely on time since surgery. These tests assess muscle strength, hop performance, and knee stability under dynamic conditions. Rushing back too soon increases the risk of graft failure or re-injury. A cautious, structured rehabilitation program supervised by a physiotherapist is essential to ensure a safe and successful return to sports after ACL reconstruction.
As with any surgical procedure, arthroscopic ACL reconstruction carries some risks, although serious complications are uncommon when performed by an experienced orthopaedic surgeon. The most common risks include infection, stiffness, and ongoing knee pain. Infections are rare due to modern sterile techniques and antibiotics, but they can occasionally occur around the incision sites or within the joint. Knee stiffness may develop if rehabilitation is delayed or movement is restricted for too long, which is why early physiotherapy is important. Another potential risk is graft failure, where the reconstructed ligament stretches or tears, either due to trauma or premature return to high-impact activities. Blood clots, or deep vein thrombosis, can develop in the leg veins after surgery, though this is also rare and usually preventable with early mobilisation and proper post-operative care. Some patients may experience numbness around the incision area, which often improves over time. Long-term risks include mild weakness, reduced flexibility, or the development of early knee arthritis, particularly in patients who had significant damage before surgery. Despite these potential complications, the success rate for ACL reconstruction is very high, and most patients achieve stable, functional knees that allow a return to sport and active lifestyles under careful medical guidance.
Preparing for arthroscopic ACL reconstruction is an important step in achieving a smooth recovery and successful outcome. Before surgery, your surgeon will conduct a detailed assessment that may include a physical examination, X-rays, and an MRI scan to confirm the diagnosis and assess any additional knee damage. You’ll also discuss your medical history, medications, and any allergies to ensure your surgical plan is safe and personalised. Prehabilitation—exercises done before surgery—plays a key role in preparation. Strengthening the quadriceps, hamstrings, and core muscles can improve post-operative recovery and reduce stiffness. Gentle range-of-motion exercises are encouraged to restore full knee movement before surgery, as going into the procedure with good mobility helps prevent complications later. In the days leading up to surgery, you’ll likely be asked to stop certain medications, such as blood thinners or anti-inflammatories, that could increase bleeding risk. Fasting for several hours before the operation is also standard practice. Arranging support for transport and daily tasks during the first few days post-surgery is highly recommended, as you’ll have limited mobility initially. Finally, understanding your post-surgical rehabilitation plan, including brace use, physiotherapy, and milestones, can help you feel confident and well-prepared for the recovery journey ahead.