The role of the iliotibial band during the pivot shift test.
Academic Article
Overview
abstract
PURPOSE: Several studies have suggested that the iliotibial (IT) band plays a role in knee laxity and that it may affect the magnitude of the pivot shift observed. However, the extent of the role played by the IT band, as well as its mechanism of action, is not currently known. This cadaveric study aimed to quantify the effect of the IT band and the hip abduction angle on the magnitude of anterior tibial translation (ATT) during the pivot shift. METHODS: Six fresh-frozen hip-to-toes specimens were used. Serial sectioning of the anterior cruciate ligament (ACL) and the IT band was performed. Lachman and mechanized pivot shift manoeuvres were employed at each stage, and ATT of the lateral and medial compartments was measured using navigation. Three hip abduction angles were tested for each condition: 0°, 15° and 30°. RESULTS: Sequential sectioning of the ACL and the IT band resulted in a significant increase in ATT in both the lateral (Intact = 0 ± 0.5 mm; ACL deficient = 8.1 ± 0.2 mm; ACL + IT deficient = 10.8 ± 0.3 mm) and medial (Intact = 6.7 ± 0.4 mm; ACL deficient = 8.4 ± 0.3 mm; ACL + IT deficient = 9.9 ± 0.3 mm) compartments. No significant increase in ATT was observed after changing the hip abduction angle at each stage. CONCLUSIONS: An increase in the magnitude of the pivot shift and the Lachman was observed as the constraint of the IT band was removed. Additionally, it was shown that the hip abduction angle at which the pivot shift test was performed did not significantly affect the magnitude of ATT in this cadaveric model.
