ACL Rupture: Reconstruction, Recovery & Return to Sport

What Is the ACL?

The anterior cruciate ligament (ACL) is one of four major ligaments stabilising the knee joint. It prevents the tibia from sliding forward relative to the femur and controls rotational stability. The ACL is particularly important for cutting, pivoting and jumping activities.

How Does the ACL Rupture?

ACL tears most commonly occur during non-contact sporting activities, a sudden change of direction, deceleration, or landing awkwardly from a jump. A "pop" is often felt or heard at the time of injury, followed by immediate pain, rapid swelling, and instability. Contact sports (football, soccer, basketball, netball, skiing) account for the majority of ACL injuries in Australia.

Diagnosis

Clinical examination reveals increased anterior laxity (positive Lachman test) and a positive pivot shift. MRI is used to confirm the diagnosis and assess for concurrent meniscal or cartilage injuries, which occur in up to 50% of ACL ruptures.

Should I Have Surgery?

Not all ACL ruptures require surgery. The decision depends on:

• Age and activity level
• Degree of instability
• Presence of associated injuries (meniscus, cartilage)
• Occupational demands

Young, active patients who wish to return to pivoting sports are generally recommended surgical reconstruction. Older, less active patients with a stable knee may be managed conservatively with physiotherapy.

ACL Reconstruction Surgery

ACL reconstruction involves replacing the torn ligament with a graft, most commonly the hamstring tendon (semitendinosus/gracilis) from the same leg, or the patella tendon. The graft is passed through tunnels drilled in the tibia and femur and fixed in place.

Surgery is performed arthroscopically (keyhole) under general anaesthetic and takes approximately 1–1.5 hours. Most patients go home the same day or the following morning.

Recovery Timeline

• Weeks 1–2: Swelling reduction, range-of-motion exercises, walking with crutches
• Weeks 3–6: Progressive weight-bearing, cycling, swimming
• Months 2–4: Strengthening, gym-based rehabilitation
• Months 4–6: Running, sport-specific training
• 9+ months: Return to competitive sport (criteria-based)