Lateral thrust is a sudden sideways movement of the knee which occurs in the early stance phase of walking when the joint space is narrowed on the medial side.

lateral thrust
At rest the knees look straight but, as the walking person takes weight on the affected side, the knee thrusts outwards.


Medial compartment insufficiency

The problem is due to early deterioration of the normal 'joint spacers' on the medial side - that is, the medial meniscus and/or the medial joint cartilage, or after a meniscectomy when the meniscus has been surgically removed.

Varus thrust

Structural and functional consequences of meniscectomy

Although a patient may feel relief after a meniscectomy, there is invariably an effect on the joint which in the longer term may lead to joint surface damage and structural changes.



Medial knee loading is altered in subjects with early osteoarthritis during gait but not during step-up-and-over task. Meireles S, Wesseling M, Smith CR, Thelen DG, Verschueren S and Jonkers I. PLoS One. 2017; 12(11): e0187583.

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