Combined ACL and peripheral instability: The Western experience

In this chapter we analyze our experience concerning ACL lesion with an associated peripheral instability, as peripheral structures are getting more and more attention. We know that combined damage of the ACL and the posterolateral structures of the knee have been associated to Chronic anterior cruciate ligament laxity, in particular rotational laxity associated with a severe pivot-shift test (PST). Posterolateral structures, that may not have been yet directly identified, probably act as secondary restraints to the PST, supplementing the primary restraint role of the ACL in anteroposterior laxity, with emphasis on rotatory laxity and internal rotation. The persistence of this rotatory laxity has been reported even after cases of uneventful ACL reconstruction, suggesting that a single-bundle intra-articular reconstruction could not be sufficient to completely restore rotational knee stability in certain patients (Tashman et al, Am J Sports Med 32(4):975“983, 2004). The rationale behind extra-articular plasty is therefore to create a restraint in internal tibial rotation, and that's why we adopted in our Institute since 1993 Marcacci’s technique with good results and good graft survivorship. Authors who favour the supplementary extra-articular plasty to standard ACL reconstruction, report the reduction of the PST and lateral tibial translation, however the introduction of evidence-based inclusion criteria for any similar technique as a primary or a revision option, is difficult and remains sporadical and empirically-based.