Which gait finding may be observed in a patient with knee OA?

Which gait finding may be observed in a patient with knee OA?

• A. Varus thrust
• B. Trendelenburg sign
• C. Antalgic gait with wide base
• D. Foot drop

Answer: (A)

Knee osteoarthritis, especially in the medial compartment, often leads to a varus alignment when the limb bears weight. In walking, this can appear as a varus thrust—an abrupt, transient bowing of the knee into varus during early stance as the leg accepts weight and the joint moment collapses due to cartilage loss and ligamentous laxity. This dynamic instability is a classic gait finding in knee OA because the damaged joint cannot maintain a straight alignment throughout the initial weight-bearing phase. Other gait signs point to different issues. A Trendelenburg sign reflects hip abductor weakness rather than knee joint pathology. An antalgic gait indicates pain avoidance and can involve a shortened stance time on the affected side; a wide base is more typical of other conditions affecting balance rather than a feature of knee OA. Foot drop denotes dorsiflexor weakness leading to toe clearance problems, not knee joint mechanics. Thus, the varus thrust best fits the gait change you’d expect with knee OA.

Knee osteoarthritis, especially in the medial compartment, often leads to a varus alignment when the limb bears weight. In walking, this can appear as a varus thrust—an abrupt, transient bowing of the knee into varus during early stance as the leg accepts weight and the joint moment collapses due to cartilage loss and ligamentous laxity. This dynamic instability is a classic gait finding in knee OA because the damaged joint cannot maintain a straight alignment throughout the initial weight-bearing phase.

Other gait signs point to different issues. A Trendelenburg sign reflects hip abductor weakness rather than knee joint pathology. An antalgic gait indicates pain avoidance and can involve a shortened stance time on the affected side; a wide base is more typical of other conditions affecting balance rather than a feature of knee OA. Foot drop denotes dorsiflexor weakness leading to toe clearance problems, not knee joint mechanics.

Thus, the varus thrust best fits the gait change you’d expect with knee OA.