Clinical anatomy of the anterior cruciate ligament and pre-operative prediction of ligament length

Abstract

BACKGROUND : Ligament grafts used in anterior cruciate ligament (ACL) reconstruction need to be the correct length for proper functioning. If the graft length is incorrect, the patient could risk knee instability, loss of range of motion, or failure of graft fixation. Easier and time-efficient reconstruction will be facilitated if the length of the ACL is predicted in advance. Apart from examining the morphological properties of the ACL, this study aimed to determine whether the epicondylar width of an individual can be used to predict ACL length and thereby assist in restoring the normal anatomy of the ACL. METHODS : Ninety-one adult cadavers were studied. Patellar ligament (PL) length, ACL length, ACL width and the maximum femoral epicondylar width (FECW) were measured. RESULTS : The morphology of the ACL and PL was determined. The results revealed that FECW was the most reliable predictor of ACL length. A linear regression formula was developed in order to determine ACL length by measuring maximum FECW. CONCLUSIONS : ACL and PL morphology compared well with the results found in previous studies. An individual's FECW can be used to predict ACL length pre-operatively. These results could improve pre-operative planning of ACL reconstruction.