Basics and Beyond ® Anatomy of the Upper Extremity

Oblique Retinacular Ligament (ORL)

• Sometimes referred to as Landsmeer's ligament
• ORL arises at the level of proximal phalanx
• A cord that runs from the sheath of the flexors (PIP joint level) to the terminal extensor tendon
• Continues to the terminal extensor tendon
• Volar to the axis of the PIP joint
• Functional importance is not totally known but it is believed to coincide with DIP joint and PIP joint movement
• When the PIP joint is flexed, the ORL relaxes allowing DIP joint flexion.  When the PIP joint extends, the ORL tightens facilitating DIP joint extension, linking PIP joint and DIP joint motion.
• Some believe that the ORL may be involved with Dupuytren’s contracture causing PIP joint flexion and DIP joint extension
• ORL contraction or tightness may cause lateral band displacement, which can lead to a boutonniere deformity.
• If the ORL is tight, the DIP joint cannot flex or will have difficulty flexing
• If DIP joint passive motion is resisted when PIP joint is extended versus flexed, then the ORL is tight or contracted since the ORL is tightened when the PIPJ is extended