Analysis of the significance of the measurement of acceleration with respect to lateral laxity of the anterior cruciate ligament insufficient knee.

The purpose of this study was to assess dynamically the lateral thrust of anterior cruciate ligament (ACL) insufficient knees, and from the findings determine any relationship between ACL insufficiency and the later development of osteoarthritis (OA). We investigated 80 knees in 40 patients awaiting ACL reconstruction and 25 knees of 25 patients, which had undergone ACL reconstruction. An acceleration sensor was fixed to the anterior tibial tubercle and this 'acted' in two directions--medial lateral and perpendicular. The peak value of the lateral acceleration immediately after heel strike was significantly greater in the ACL insufficient knees when compared to their opposite normal knees. When the periods from injury were compared, the lateral thrust of the injured side after 3 years or more was significantly greater than in the first 3 years. There was no significant difference between the normal knees and the ACL reconstructed knees. The results indicated that the lateral acceleration peak value was significantly greater in the ACL insufficient knees than in their opposite normal knees.