The knee is one of the largest joints in the body — where the thigh bone (femur) meets the leg bone (tibia), with the kneecap (patella) in front. It's stabilised by major ligaments, including two cruciate ligaments running criss-cross inside the joint.
The ACL is the main restraint to forward translation of the tibia relative to the femur. It is one of the commonest ligaments to be injured in sport.
Causes of ACL injuries
An ACL can be injured in isolation, or alongside the collateral ligaments or meniscus, depending on the force and mechanism of the injury — commonly a sudden twist, pivot or awkward landing.
Main symptoms of an ACL tear
- A 'POP' sensation at the moment of injury or a fall
- Instability of the knee joint
- A 'give way' feeling, with locking if a meniscal tear is also present
On examination there is effusion (swelling) and instability, demonstrated by the Drawer's and Lachman's tests. Diagnosis is confirmed with an MRI, which shows the extent of the injury and guides the correct line of treatment. A standing X-ray of the lower limb tells us about the overall alignment of the knee.
Treatment
The standard treatment of an ACL injury is arthroscopic ACL reconstruction using the patient's own (autologous) grafts — most commonly hamstrings, quadriceps or BTB (patella tendon) grafts. The patient is admitted on the day of surgery; after routine investigations, surgery is performed the same day and typically lasts around one hour.
Rehabilitation
- Rehabilitation begins the same evening, under an expert physiotherapist
- The next day, the patient walks with crutches or a walker
- Rehabilitation continues for 4–6 weeks
- Driving is usually possible after 6 weeks
- Sports activities usually resume after 9–12 months, as the load on the knee is gradually increased
Originally published on dranilraheja.com.
