ACL Reconstruction

The anterior cruciate ligament runs diagonally through the middle of the knee, connecting the thighbone, or femur, to the shinbone, or tibia. Together with the other ligaments it keeps the shinbone from sliding forward and rotating too far, which is what allows you to cut, pivot and land with confidence. Because the ligament sits in joint fluid and has a limited blood supply, a complete tear does not usually heal back together, so surgery replaces it rather than stitching it. In ACL reconstruction the torn remnants are cleared, small tunnels are drilled in the femur and tibia at the points where the original ligament was attached, and a tendon graft is passed through them and fixed in place. Over the following months the body gradually remodels the graft into tissue that behaves like a ligament, a process known as ligamentisation, which is one reason why rehabilitation takes so long.

An ACL tear typically happens during football, basketball, skiing, handball or similar sports, when the foot is planted and the knee twists, or when the knee straightens suddenly on landing. Many people feel or hear a pop, followed by swelling within hours. The diagnosis is made by examination and confirmed by MRI, which also shows damage to the meniscus, the cartilage cushions of the knee, or to other ligaments. Reconstruction is usually recommended for people who want to return to sports involving pivoting, jumping or quick changes of direction, for people whose knee keeps giving way during ordinary activities, for physically demanding jobs, and when a repairable meniscus tear or another ligament injury is present. Repeated episodes of giving way can damage the meniscus and joint cartilage over time. Less active people whose knee feels stable after a structured physiotherapy programme may reasonably choose not to have surgery, a decision to make together with the surgeon.

ACL reconstruction is done arthroscopically, through two or three small incisions about 1 centimetre long, using a thin camera and fine instruments. It is carried out under general anaesthesia or a spinal anaesthetic, often with a nerve block to ease pain afterwards. The surgeon first inspects the whole joint and treats any meniscus or cartilage damage. The graft is then taken through a separate small incision. The three common choices from your own body are the hamstring tendons at the back of the thigh, the central part of the patellar tendon below the kneecap with a small bone block at each end, and part of the quadriceps tendon above the kneecap. Each has advantages, and the choice depends on your sport, age, anatomy and the surgeon's experience. Donor grafts from a tissue bank are sometimes used, mainly for older or revision patients, as they fail more often in young athletes. Tunnels are drilled, the graft is passed through and fixed with screws or buttons, and the operation usually takes about 1 to 2 hours.

Good candidates are active adults and teenagers with a confirmed ACL tear, a knee that feels unstable and the time and motivation for a long rehabilitation. In children whose growth plates are still open, special techniques that protect those plates are used. Surgery is usually planned a few weeks after the injury, once swelling has settled, the knee straightens fully and the thigh muscles are working again, because operating on a stiff, swollen knee raises the risk of lasting stiffness. This preparation phase, sometimes called prehabilitation, is guided by a physiotherapist. You will need an MRI, a clinical examination, blood tests and a review of your medicines, with blood thinners paused if advised. For international patients, the MRI images and report can usually be reviewed remotely, so the graft choice and timing are discussed before travel and confirmed at the in-person consultation on arrival.

Most people go home the same day or the next morning, walking with crutches and allowed to put weight on the leg as comfort permits, unless a meniscus repair calls for more protection. Some teams use a brace in the first weeks. Physiotherapy starts within days, focusing on straightening the knee fully, reducing swelling and switching the thigh muscles back on. Crutches are usually set aside within one to two weeks, desk work often resumes after one to two weeks, and driving may take two to six weeks depending on which knee was operated on. Running usually starts around three to four months, followed by agility and sport-specific training. For travel, plan about 7 to 10 days abroad so the wound can be checked and the exercises taught in person; your team will advise on preventing blood clots during the flight. Most of the rehabilitation then continues with a physiotherapist near home, guided by a written programme and remote follow-up.

ACL reconstruction is a common and well-established operation, and most patients regain a knee that feels stable in daily life and sport. Like any surgery it has risks. Infection inside the joint is rare but serious and needs prompt treatment. Stiffness, especially difficulty straightening the knee fully, is one of the more common problems and is reduced by good preparation and early physiotherapy. Other risks include numbness of a patch of skin near the incisions, pain at the front of the knee or when kneeling, particularly after a patellar tendon graft, blood clots and, rarely, problems with the fixation. The new graft can tear again, a risk that is higher in young people returning to pivoting sport and in those who return too early, which is why return is based on passing strength, hop and movement tests, usually not before about nine months. Even after a successful reconstruction, the knee keeps a higher long-term risk of osteoarthritis than an uninjured knee.