BACKGROUND: The purpose of this systematic literature review is to analyse the isolated biomechanics of the posterior oblique ligament of the knee. In the current literature, the biomechanical aspect of the posterior oblique ligament was analysed in several articles, but this was always done in association with other capsuloligamentous structures.
METHODS: A systematic review of the existing literature was performed to identify all studies dealing with the biomechanics of the posterior oblique ligament. Two independent investigators performed the research using the MEDLINE, CINAHL, Scopus, Embase and Cochrane databases.
FINDINGS: A total of 10 articles analysed the biomechanics of the posterior oblique ligament, confirming the importance of this ligament for the stability of the knee in different positions. The posterior oblique ligament is the main stabiliser against internal rotation in early flexion angles (0°-30°) and it is an important restraint to posterior tibial translation in the posterior cruciate ligament deficient knee. Furthermore, the posterior oblique ligament bears up to 47% of the force borne by the anterior cruciate ligament in resisting the internal rotation loads when a pivot-shift maneuver is simulated.
INTERPRETATION: This review confirms that the posterior oblique ligament is an anatomically well-defined and distinct structure that plays a key role in stabilising the knee, especially in internal rotation. The posterior oblique ligament is frequently injured along with other anatomical structures. Future studies should develop clinical tests to evaluate the functionality and stability of the the posterior oblique ligament.