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 ®

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