What confirmation for clinical diagnosis of ACL tears?

Dr MH Binet

Knee ACL tears are a common ski injury. The first diagnosis is made by the hand of the physician. More experienced is the practitioner, more ACL tears are clinically found out. But with the increasing numbers of old injuries, of partial tears of the ACL, of associated lesions, the diagnosis is not always clear after the clinical tests.

The other exams currently made in the emergency rooms are X Rays. We know that the radiography do not bring often useful information except the classic “Segond’s fracture”. The gold standard is the MRI which is not available in the medical centres of the ski resorts.

A new device called Genou Rob is presented. This machine is able to measure the tibial plateau movement when applied different loads. The mobility is measured in mm comparatively to the non-injured knee. When the difference between the curves is larger than 2.8 mm and when the curves inclination is different, the ACL is supposed to be torn; when the difference is larger than 2 mm and if the curves inclination is not different, the ACL is supposed to be partially torn.

Study:

We have tested this machine with recent knee injuries all tested have been made before 24 hours after the injury.

96 fresh knee injuries have been tested: the clinical tested allow to separate in:

ACL tears: with a positive Lachman and Jerk test

ACL possible partial tears: with asymmetric Lachman test and positive Jerk.

Doubt on ACL damage: small tibial plateau mobility when Jerk test is applied.

Results:

Only 3 fresh knee injuries could not be tested because of pain (mostly after hemarhrosis punction)

All clinically ACL diagnosis have been confirmed.

75% of the clinically uncertain injuries have been classified as total ACL tears.

Discussion :

This machine is not able to be used instead an MRI, it does not bring the same information (no information on meniscus tears, no information on bone bruised) but the results brought by this machine can confirm the clinical impression and sometimes help to find some ACL tears not easily apparent with clinical tests.

We think a comparative study between results of GenouRob and MRI would help to separate complete tears of ACL and partial ruptures.

Conclusion:

GenouRob has been invented by a specialized knee-surgeon to confirm the results after surgery. But it is definitely a great help for physicians in emergency rooms to confirm the ACL tears.