Anterior cruciate ligament is one of the main stabilisers of the knee along with posterior cruciate ligament. They are called cruciate ligaments because they form a cross inside the knee.
It is one of the strongest ligaments in the body and therefore great force is required to tear the ligament. The most common cause of injury is a pivoting mechanism of upper body at the knee with a planted foot. Other mechanism are a valgus force (ie imagine the leg is pulled out across the knee. This mechanism commonly results in associated medial collateral ligament injury.
(Image courtesy: https://commons.wikimedia.org/wiki/File:918_Knee_Injury.jpg)
The common presentation is an acute definite injury followed by immediate swelling and pain in the knee. Weight-bearing on the knee may be difficult but may still be possible, Once the acute symptoms settle down, the most common symptom is feeling of instability or the knee actually giving way.
The treatment of ACL injury can be conservative or surgical. Few papers have reported upto 70% successful conservative treatment for ACL injuries in low demand individuals. However the current consensus favours operative treatment, as the rate of re-injury within one year has been reported to be quite high in more recent prospective studies, along with injury to adjacent structures such as meniscii.
Surgical treatment is mainly reconstruction rather than repair. Reconstruction basically means that patients own spare tendon is used to replace the torn ACL. The spare tendon can be one or two of the hamstrings tendon or a part of the patellar tendon or peroneus longus tendon. The tendon is harvested and fixed inside the bone tunnels drilled in femur and tibia using special screws (interference screws) or anchors or buttons anchored outside the bone, No matter what tendon is used, or what fixation method is used, the results are predictably good for each and it ultimately boils down to surgeon preference.
ACL surgery requires extensive rehabilitation post-operatively and most hospitals now have a graded physiotherapy protocols leading up to return to sport testing, Typically this is 1 year post surgery for high end contact sports.
While ACL injury is common, treatment is complex and requires a multi-disciplinary team approach for optimal outcomes.
To know more details about the actual ACL surgery, or specific individualised advice, click the link below: