Dial Test

Original Editors - Gaëlle Vertriest as part of the Vrije Universiteit Brussel's Evidence-based Practice project

Top Contributors - Tomer Yona, Gaëlle Vertriest, Rachael Lowe, Admin, Kim Jackson, Yvonne Yap, Uchechukwu Chukwuemeka, Daphne Jackson, Wanda van Niekerk, Tony Lowe, Kai A. Sigel and WikiSysop

Purpose 

The purpose of the Dial Test is to diagnose posterolateral instability and to differentiate between isolated PLC injury and combination PLC/PCL injury .
The test can be clinically valuable when:

1. Three posterolateral structures (Popliteus tendon, Popliteofibular ligament, Lateral collateral ligament) are injured.

2. There is combined injury to the PCL and two other posterolateral structures.

Its important to know that when only one or two structures are injured , the dial test is not enough to diagnose the injury.             For an isolated PCL tear, the posterior drawer test or sag tests are more relevant.

Clinically Relevant Anatomy

 Relevant structure of the posterolateral corner in the knee 

Technique

It is possible to do the test both in a prone and supine position, and is performed in both 30° and 90° knee flexion.  The dial test inspects the external rotation at the knee joint.   

The patient is in prone: performing the test is sensitive to the notice of a PLC-injury in a PCL-injured knee.  The knees are held together and bent at 30°, the therapist stands behind the table and keeps the feet in dorsiflexion. He turns the lower legs and feet outwards and compares the motion of the feet.   Repeat the test with the knees at 90°.   

The patient is in supine: there are 2ways to perform this test.
1) As in prone position: the knees are held together and bent at 30°, the therapist stands behind the table and keeps the feet in dorsiflexion. He turns the lower legs and feet outwards and compares the amount of rotation of the tibial tubercle. Repeat the test with the knees at 90°.  

2) One leg is hanging off the edge of the table with the knee in 30° of flexion. The therapist stands beside the table and stabilizes the thigh with one hand; the other hand executes an external rotation of the foot. By observing the tibial tubercle motion, we can indicate any posterolateral knee injury. With an increase, compare to the normal contralateral side.

  

If the dial test at 30° is positive, perform the test when the knee is flexed on 90°. The thigh does not touch the table, hold the leg in your hands or put the foot down on the table.

 

Key Research

add links and reviews of high quality evidence here (case studies should be added on new pages using the case study template)

Evaluation

The evaluation of the test for both prone and supine position:
The dial test is positive when there is more than 10° of external rotation in the injured knee compared to the uninjured knee.  

Standard injury	Mild injury	Moderate injury	Severe Injury
<5°	6-10°	11-19°	>20°

 

There are different injuries:
    - An isolated injury to the PLC: more than 10° of external rotation in the injured knee is present at 30° of flexion, but not at 90° of flexion.
    - Instability of the PCL: more than 10° of external rotation in the injured knee is present at 90° of flexion, but not at 30° of flexion.
    - A combined injury: more than 10° of external rotation in the injured knee is present at 30° and 90° of flexion. This is an injury of the PCL and the PLC.

Recent Related Research (from Pubmed)

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