The significance of isometer measurements and graft position during anterior cruciate ligament reconstruction.

Abstract

Intraoperative isometry measurements are commonly performed before bone tunnel drilling during anterior cruciate ligament reconstruction. The relationship between initial isometer measurements and final graft isometry, however, is unclear. We tested 15 cadaveric knees to determine the relationship between isometer readings and final graft isometry. We found that isometer readings may vary widely from final graft isometry because of eccentric placement of the anterior cruciate ligament graft within bone tunnels. Isometer measurements may be used, however, to predict accurate final graft isometry for specific graft positions within the bone tunnels.