- The anterior drawer test is a physical examination doctors use to test the stability of the knee’s anterior cruciate ligament (ACL).
- Doctors may use this test, along with images and other exams, to determine if a person has injured their ACL and recommend treatment options.
- This test may not be as accurate in diagnosing an ACL injury as some other diagnostic options.
A doctor can usually conduct an anterior drawer test in less than five minutes. The steps for the anterior drawer test are usually as follows:
- You’ll lie down on an exam table.
- A doctor will ask you to bend your knee, leaving your foot on the exam table.
- The doctor will put their hands on either side of your lower knee joint. They will put gentle pressure behind your knee and attempt to move the lower leg slightly forward. Your foot will stay on the exam table during that time.
- If your tibia (lower leg) moves out of place during the test, this indicates an injury of the ACL. Your ACL is responsible for maintaining the stability of the tibia. If the tibia moves forward, this indicates to a doctor the ACL isn’t working properly.
- A doctor will grade or estimate how severe the injury is by how far they can displace the ACL. They grade the tear from one to three (I, II, or III), with three being the worst tear. A grade I tear moves 5 millimeters, a grade II tear moves between 5 and 10 millimeters, and a grade III tear moves more than 10 millimeters.
A doctor can also conduct this exam while you are seated with your feet flat on the floor. Ideally, the exam shouldn’t be painful, and you usually don’t have to do anything special to prepare.
A doctor may also test the functioning of other knee ligaments by rotating your knee one direction and then the other to test how well these ligaments work. Unfortunately, it’s possible to injure more than one ligament at a time.
According to an article in
Some older studies note a lower sensitivity (accuracy) level for detecting ACL injuries — as low as
Another test used to diagnose ACL injuries is the Lachman test. The same 2013 study reports the Lachman test has a sensitivity of about 94 percent.
Both tests improved their accuracy when people were under general anesthesia.
Doctors will use the anterior drawer test findings along with other assessments to confirm if you have injured your ACL.
If the anterior drawer test is positive, and the ligaments aren’t as supportive as they should be, a person may need a variety of treatments based on the severity of their injuries.
Examples of treatments after positive test results, include:
- at-home care, such as rest, ice, compression, and elevation
- protective braces
- and physical therapy to strengthen the muscles around the injured leg
In some instances, a doctor may recommend surgery. This is especially true if a person has injured multiple ligaments or is very physically active and wants to return to the playing field.
The anterior drawer test is one test for ACL injuries, but it isn’t the only one.
Doctors may also use a physical exam called the Lachman test to evaluate the ACL. This test involves feeling the back of the knee while moving the joint. The damaged ligaments often feel “mushy” to the examiner.
The pivot test is another test a doctor may use. This test involves extending, rotating, and flexing the knee. A doctor will feel the knee joint and determine how the tibia interacts with the femur (upper leg bone).
The McMurray test is another option. This test involves manipulating the leg in such a way that a doctor will hear or feel a “snap” of the knee’s meniscus when the knee is extended.
Doctors often recommend imaging studies to visualize the ACL injury as well as bone or soft tissue injuries. An MRI scan is usually especially helpful.
A doctor will also take into consideration if a person experienced an injury. Hearing a “pop” during the injury, could indicate a person had a ligament injury. Immediate pain or instability can also indicate an ACL tear. A doctor will also ask a person to walk and view how unstable the knee is.
With several of these diagnostic methods combined, a doctor will make a diagnosis.
The anterior drawer test can help confirm if you’ve injured your ACL. Doctors will likely use it with other tests to be thorough.
If your injury is severe, a doctor will recommend a combination of treatments that range from exercise to surgery. If you think you may have injured your ACL or knee, talk to your healthcare provider, who will likely refer you to an orthopedic surgeon.