ACL Reconstruction Surgery
The ACL is the main ligament that keeps the knee stable during twisting. When it tears the knee gives way; active patients are usually treated with arthroscopic reconstruction.
The anterior cruciate ligament (ACL) connects the thigh bone to the shin bone inside the knee and keeps the knee stable, especially during twisting and sudden changes of direction. An ACL tear is one of the most common serious knee injuries in sport.
How does the ACL tear?
The injury usually happens without contact, during a sudden stop, a change of direction or a poor landing from a jump. Football, basketball, volleyball, handball and skiing carry a higher risk. Many patients describe hearing a “pop” in the knee at the moment of injury. The knee swells within a short time and it becomes hard to keep playing.
Symptoms
- Marked swelling within hours of the injury
- A feeling of instability and giving way, especially when turning
- Unsteadiness when walking, difficulty going down stairs
- Catching and locking if a meniscus tear is also present
Diagnosis
On examination, tests such as the Lachman and anterior drawer tests assess whether the shin bone slides forward too much. MRI shows the ligament tear and the meniscus, cartilage or other ligament injuries that often come with it.
Treatment options
Non-surgical treatment
For less active patients who do not play pivoting sports and do not experience giving way, a physiotherapy programme focused on strengthening can be enough.
ACL reconstruction
Reconstruction is recommended for active patients, those who want to return to sport and those whose knee gives way in daily life. Because a torn ACL usually does not heal when stitched, a new ligament is made using a graft from the patient’s own tendons (the hamstring tendons, the patellar tendon or the quadriceps tendon). The operation is done arthroscopically through small incisions. The graft is placed in tunnels drilled in the bone and fixed with special screws or suspension devices. Any meniscus tear is treated in the same session.
Knees that stay untreated for a long time and give way often are at higher risk of meniscus and cartilage damage, so the timing of treatment matters.
Rehabilitation and return to sport
Rehabilitation is as important to the result as the surgery itself.
- First 2 weeks: Reducing swelling, straightening the knee fully, walking with support
- Weeks 2-6: Stopping crutches, normal walking, muscle strengthening
- Months 3-4: Gradual return to running
- Months 6-9: Sport-specific training and then competition, once strength, balance and functional tests are adequate
The return-to-sport decision is based on muscle strength and functional tests, not on time alone.
Choosing the graft
The tendon used for the new ligament is chosen according to age, sport, any kneecap symptoms and previous operations. Each graft has strengths and weaknesses, and the choice is discussed together before surgery.
Frequently asked questions
Can an ACL tear heal without surgery?
A completely torn ACL usually does not heal on its own. In less active patients, however, a strengthening programme can restore a good degree of knee stability.
When will I walk after surgery?
Patients usually start walking with support the day after surgery. Crutches are often stopped within a few weeks.
Can the new ligament tear again?
There is a risk of re-tear, and it is higher with an early return to sport. Completing rehabilitation and passing the tests before competing reduces this risk.
Do I need physiotherapy before surgery?
Yes. Recovery after surgery is easier if the swelling has settled, the knee straightens fully and the muscles are strong beforehand.
The information on this page is general and does not replace an examination. An examination is needed to decide which treatment suits you.