Review Question - QID 5721

An increased adductor moment during gait is associated with progression of knee osteoarthritis.

While there are biological, mechanical, and structural factors associated with the progression of knee arthritis, mechanical loading during walking has been identified as a critical factor. Most commonly, the external knee adduction moment has been the target of various interventions that aim to reduce joint loading and slow disease progression. The external knee adduction moment complements the static mechanical axis alignment measure by characterizing the ambulatory distribution of load between the medial and lateral compartments. The adduction moment has been shown to be associated with cartilage changes in medial knee arthritis as well as being sensitive to disease progression as measured by radiographs and cartilage volume.

Chehab et al. evaluated patients after 5 years of osteoarthritis advancement, and were able to show that knee adduction moments and knee flexion moments are directly correlated with thickness of remaining femoral and tibial cartilage. They report that the adduction moment is most related to the tibial cartilage thickness, while the knee flexion moment is most related to the femoral cartilage thickness.

Illustration A is a diagram that shows how the adduction moment medializes the joint forces.

Incorrect Answers:
1: This would result in a Trendelenburg gait from the abductor weakness.
2: This would result in a Trendelenburg gait from the abductor weakness.
3: This would not result in an increase in adductor moment of the lower extremity with ambulation.
4: This would lead to a stiff-ankle gait and a corresponding increase in midfoot motion.