Dial Test for Knee Instability
The Dial Test comes from a paper in 1991 from Dr. Richard Loomer (Loomer, R. L. (1991). A test for knee posterolateral rotatory instability. Clinical Orthopaedics and Related Research (1976-2007), 264, 235-238). He developed this test for knee posterolateral instability that is a variation of the posterolateral drawer test. He describes this test based upon demonstrations from Dr. John Patrick McConkey where he describes holding a patient’s hip and knee in 90° of flexion then externally rotating the tibia to see if the leg rotates posteriorly and externally. In a later study (Veltri, D. M. & Warren, R. F. (1993). Journal of the American Academy of Orthopaedic Surgeons, 1 (2), 67-75), there is discussion that when the knee has more posterior translation, external rotation and varus angulation at 30° compared to 90°, it’s more evident that there is a posterolateral corner injury than a PCL injury.
How to perform it:
In the original article it was performed as follows:
-Patient is in supine and examiner at their feet
-Flex the hips and knees to 90° with the knees together.
-Externally rotate the feet
A positive is both when there is excessive external rotation and the tibial tubercle drops posteriorly
There is a more common variation:
-Patient is in the prone position with examiner at their feet
-Flex the knees to 30° and externally rotate the feet, compare both sides
-Flex the knees to 90° and externally rotate the feet, compare both sides.
A positive is:
-Isolated posterolateral injury, more than 10° of ER at 30° but not 90°
-PCL instability if more than 10° of ER at 90° but not at 30°
-Combined PCL injury and instability if more than 10° ER at 30° and 90°
One paper (Norris, R., Kopkow, C., & McNicholas, M. J. (2018). Interpretations of the dial test should be reconsidered. A diagnostic accuracy study reporting sensitivity, specificity, predictive values and likelihood ratios. Journal of ISAKOS, 3(4), 198-204) looked at 87 subjects who were undergoing knee ligament surgery. They found the test had a sensitivity of 20% and specificity of 100%. They came to the conclusion that if the test is negative at 30° then it can rule out a posterolateral corner (PLC) injury, if it’s postivie at 30° and 90° there is the PLC injury with a possible PCL or other knee ligament injury. Also, if the test is positive, that other tests should be performed too
What do you think of this test? How do you use it? Let me know in the comments.
Connect with me!!
Instagram: / matt_pt_dip_mdt
TikTok: / matt_thept
Medbridge: https://medbridgeeducation.com/matt-t... Save over $100 with code MATT
Find some deals here: https://linktr.ee/mattthept
Pick up a shirt here: https://gagreflextees2025.myshopify.com/