Despite the multiple patho-aetiological basis of Hallux valgus (HV), corrective osteotomy is a common and globally performed orthopaedic procedure. Over-correction of the inter-metatarsal angle (IMA), however, is not without consequence. Through increased joint pressures, over-correction may predispose to joint degeneration. Hypothesizing that over-correction leads to an increase in intra-articular joint pressures, we constructed a mechanical simulation of the 1st metatarsal-phalangeal joint. The vector forces of Flexor Hallucis Longus, Extensor Hallucis Longus, Extensor Hallucis Brevis and Adductor Hallucis, acting upon the 1st proximal phalanx were simulated with tensioned weighted rope. A Foley catheter balloon inflated to 1.5ml, simulated intra-articular distractive vector forces. The joint was freely mobile. At 5° IMA intervals from 10° valgus to 15° varus, intrarticular pressures were recorded using a contact pressure (Graseby™, Introduction
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