Tamir Pritsch, Nehemia Blumberg, Amir Haim, Shmuel Dekel and Ron Arbel
The authors of this study hypothesised that a medial collateral ligament (MCL) tear will also produce a positive dial test and that a valgus stress test would provide differential diagnostic information. Grade 3 tears to fresh cadaveric knees were simulated and the amount of tibial external rotation (the dial test) was measured for each knee before and after the transection. The results showed a significant increase in external rotation of the knee in 30Â° and 90Â° of flexion. More over, external rotation in 30Â° was significantly greater than external rotation in 90Â° of knee flexion. The authors concluded that whenever suspecting a posterolateral complex injury, one has to carefully perform a valgus stress test in 0Â° and 30Â°. Although the support of a clinical study is needed in order to make a definite conclusion, the dial test is probably not reliable in the presence of medial instability, and alternative diagnostic measures should be used.
Injury, Volume 37, Issue 10, October 2006, Pages 1011-1014