Execution:
- Patient is in supine lying position with the knees bent to 90° so that the foot soles touch each other
- The examiner places both hypothenar on the anteromedial aspect of the patient’s tibias and the middle fingers palpate the lateral joint line, lateral collateral ligament and posterolateral corner
- The examiner applies a virus force to both knees simultaneously
Positive Outcome: The test is positive in case a noticeably palpable difference on the affected side is palpated compared to the non-affected side
|
Study |
Reliability | Sn | Sp | LR+ |
LR- |
| Gomes et al. (2016) |
Inter-rater ĸ=0.86 |
91.7 | 94.5 | 16.67 |
0.09 |
| Comment: Norris et al. (2017) argue that while the test position may exert load on the lateral collateral ligament, it may not suffice to also assess the posterolateral corner. From a biomechanical point-of-view, in order to stress the popliteus tendon and popliteofibular tendon the tibia has to be externally rotated. They go on to state that the frog leg test position, with the femur in external rotation, will lead to relative internal tibial rotation and thus the PLC structures cannot be accurately assessed. While the test can be a good way to assess the integrity of the lateral collateral ligament, which is an integral part of the PLC, they mention that intraoperatively, PLC injuries can occur without the involvement of LCL injuries and may therefore be missed by the test | |||||
