ACL (Anterior Cruciate Ligament) Injury

The ACL is one of the most commonly injured ligaments in the knee.  It helps provide stability to the knee joint, and is especially useful with cutting and pivoting activities.  It can be injured without direct contact to the knee, and is often torn when the body is rotating and the foot is planted.  When the ligament tears, patients often feel a “pop” in the knee and have swelling.  It may be difficult to put weight on the affected leg for several days.  Initial treatment includes ice, compression, and elevation.

ACL tears can often be diagnosed on physical examination.  An MRI is often used to confirm a tear of the ligament, as well as to identify whether additional structures have been injured.  A high percentage of patients with ACL tears have continued instability in the knee during sporting or work-related activities. 

The majority of patients who are active with sports or at work may require anterior cruciate ligament reconstruction. Surgical treatment then requires reconstruction of the ligament using a graft taken from either your own body (autograft) or a donor (allograft).  The most appropriate type of graft for any individual patient is determined through an evaluation and discussion with your sports medicine physician.  The appropriate graft is then threaded through the knee joint with the help of arthroscopic tools and placed where the normal anterior cruciate ligament was.  The graft is secured to both the thigh bone and the lower leg bone and then biologically heals in to become the anterior cruciate ligament over the following months.  Any other injuries to the knee joint are also arthroscopically evaluated and treated at the same time.  This outpatient procedure often requires a period of bracing followed by a structured physical therapy program.  


Following ACL reconstruction, a patient’s return to such activities as biking may occur within the first 3 to 6 weeks, treadmill running by 10 to 12 weeks, outdoor running by 3 to 4 months, and full unlimited pivoting type sports by 6 to 8 months. 

ACL Injury Prevention (AOSSM) 

ACL Injury (AAOS)