LIVRE JDG 2016

SECONDARY RESTRAINTS TO INTERNAL ROTATION…

In contrast, Kittl found the ALL played no

significant role in rotational control [6]. In a

robotic experiment similar to that of Parsons,

using a six degree of freedom system, he

determined the superficial and deep components

of the ITB to be the primary restraints to

internal rotation from 30-90°, with the ACL

having a significant contribution at 0° only. Al

Saiegh found no increase in internal rotation

after division of the ALL in a navigation based

study, although the ALL was identified in only

six of 14 specimens in this study [34].

Fig. 2:

Variation in impact of ALL sectioning on rotation between specimens, with little effect in cadaver 2

(a) and large effect in cadaver 5 (b). Ext rot, External rotation; Int Rot, Internal rotation. a) Extension, b) 45°.

Fig. 3:

Internal rotation in extension (a) and at 45° of flexion (b). In extension loss of the lateral meniscal

posterior root causes a significant increase in internal rotation, while at 45° loss of the ALL is more

important. ACL-, ACL deficient state; M-/ALL+, Meniscal root sectioned with ALL intact; M+/ALL-, Meniscal

root intact, ALL sectioned; M-/ALL-, both meniscal root and ALL sectioned.