Developed
by Roland Jakob
The Rolimeter is designed for measuring anterior and posterior knee joint laxity during Lachman, anterior drawer, and «step off» tests.
Description Rolimeter™
by Aircast ®
First Example
R Knee
- Chronic anterior instability with a gross Lachman value of 15 mm
- While the Anterior drawer in Flexion measures 8-10 mm only
- These values determine a pure anterior instability
Second Example
L Knee
- Testing for absent hyperextension
- The Posterior drawer in extension is positive on L Knee
- In flexion the Left anterior tibial contour is reversed pointing to a posterior sag sign
- Put the RM first on the L knee bringing the feeler in contact of the TT, then on the R knee to detect a posterior sag in mm on the L Knee
- The full reduction of the posterior drawer at 80° out of the sag position can be detected as soon as the thigh muscles are relaxed
L Posterior drawer in Extension
- Demonstration of the different steps to detect the posterior drawer (Reversed Lachman) in the 25° flexed L knee. Same sequence but with «changed hands»
- To complete, and in analogy to an «active anterior drawer» the patient’s quad muscles lift the foot against resistance pulling the tibia out from the posterior sag into a neutral position