Overview of anterior cruciate ligament (ACL) tear

Figure 1. Key points for anterior cruciate ligament (ACL) tear.

[NB1]

  • Anterior cruciate ligament (ACL) tear is a common sports-related injury.
  • Early clinical diagnosis is difficult because of swelling.
  • Magnetic resonance imaging (MRI) scan is usually the investigation of choice.
  • Initial management should involve the POLICE regimen [NB2], analgesia and nonweightbearing.
  • Counsel patients about nonsurgical and surgical treatment options.
Note:

NB1: This list is a summary guide only; refer to full text.

NB2: POLICE = Protection, Optimal Loading, Ice, Compression, Elevation.

The anterior cruciate ligament (ACL) prevents anterior translation of the tibia on a fixed femur and is important in maintenance of rotatory stability of the knee. The most common injury to the ACL is a complete tear.

ACL tears occur most frequently in a sporting situation when the person is landing from a jump, pivoting on the knee, or decelerating suddenly, with the knee in a slightly flexed and valgus position. Many ACL tears occur in noncontact situations, but they also occur in combination with medial collateral ligament and medial meniscal injuries, following application of a significant valgus stress to the knee.