What does it mean when a joint is open-pack?

What does it mean when a joint is open-pack?

• A. The ligaments are slack
• B. The least amount of cartilage is contacting
• C. The joint surfaces have no contact
• D. The joint surfaces are maximally congruent

Answer: (B)

Open-packed position is the loose-packed state of a joint, where the capsule and ligaments are lax and the joint is in its least congruent arrangement. In this position the joint surfaces are not pressed firmly together, so there is minimal contact between the cartilage surfaces and the joint has its greatest amount of space or play. That is why describing it as the least amount of cartilage contacting best captures what happens in open-pack. The ligaments being slack is part of this state, but the defining feature is the reduced contact between the articulating surfaces, not a complete lack of contact or maximal surface congruence.