Introduction: The conventional radiological assessment of hallux valgus (HV) involves measuring the intermetatarsal angle, HV angle, congruity of the metatarsophalangeal joint and the overall clinical deformity of the forefoot. However, in the current practice, these angles are seldom measured. We observed consistent displacement of the lateral sesamoid (LS) along with HV deformity. The position of the LS in relation to the head of the first metatarsal has never been studied before. We aim to study this pattern of the LS and to quantify the severity of the deformity which could help make clinical decisions.

Methods: 112 radiographs of 60 consecutive patients who underwent a weight bearing radiographs of their feet were studied. Statistical analysis was performed to identify the correlation of displacement with conventional angle measurements.

Results: A definite pattern in displacement of the lateral sesamoid was noted. This displacement also showed a statistical correlation with the conventional measurement of inter-metatarsal angle.

Discussion: Previous research which studied the displacement of medial sesamoid in these deformities was not received with great enthusiasm due to the difficulty in locating the medial sesamoid through the head of the metatarsal. In contrast, the lateral sesamoid lies laterally and any progressive deformity makes it more accessible to assessment. We report a consistent pattern in the displacement of the LS and classified as the position as normal, mild, moderate and severe. As it does not involve any measurements, we believe, this is a quick and reliable technique of assessment of HV deformity and should help to base our operative decisions.