Assessing Sesamoid Subluxation: How Good Is the AP Radiograph?

Abstract

Subluxation of the metatarsosesamoid joints frequently occurs with the development of hallux valgus deformity, and the restoration of a normal metatarsosesamoid articulation has been proposed as essential for achieving a biomechanically sound operative result. The position of the sesamoid bones on the AP radiograph is used often to assess the pre- and postoperative relationship between the hallucal sesamoids and the metatarsal sulci. We evaluated the validity of this approach. Thirty subjects with hallux valgus and 30 control subjects participated in this study by undergoing both AP and tangential weightbearing radiographs. The sesamoid station on the AP radiographs was compared with the position of the sesamoids on tangential radiographs, using a new continuous measure to estimate subluxation. In approximately half of the cases, we found a difference between the apparent sesamoid station on the AP radiograph and the true position on the tangential one. Increased metatarsal rotation was associated with misclassification of the sesamoid station on the AP radiograph. We conclude that the standard method for measuring the sesamoid station on the AP radiograph is not valid. Surgeons wishing to evaluate the metatarsosesamoid joint should obtain weightbearing tangential radiographs.

Quantitative Analysis of the Degree of Frontal Rotation Required to Anatomically Align the First Metatarsal Phalangeal Joint During Modified Tarsal-Metatarsal Arthrodesis Without Capsular Balancing

“…This result is consistent with the studies by Inman (20), Talbot and Saltzman (21), and Dayton et al (13,14), which showed a pronated metatarsal will increase the sesamoid position on anteroposterior radiographs. In conjunction with the work by Okuda et al (6,12,18) and Grode and McCarthy (1), we advance the idea that the sesamoid position, lateral rounding of the metatarsal head, and the appearance of a medial eminence are effective indicators of the rotational position in the assessment, correction, and follow-up of patients with bunion deformities.…”

The Relationship Between the Sesamoid Complex and the First Metatarsal After Hallux Valgus Surgery Without Lateral Soft-Tissue Release: A Prospective Study

“…They recommended taking measurements from tangential radiographs using the Walter-M€ uller view. Some investigators have agreed with them (22,25); however, the Walter-M€ uller view requires dorsiflexion of the MTPJ (1,25,29), which moves the sesamoid complex distally and dorsally.…”

“…Currently, some surgeons have questioned just how best to determine the position of the sesamoid complex, and some have studied the relationship between the first metatarsal head and the sesamoid complex (21,23,29,40). Talbot and Saltzman (29) reported a discrepancy in the measurements between anteroposterior and tangential simple radiographs in 50% of 60 cases.…”

“…The position of the sesamoid complex relative to the first metatarsal has been studied by several investigators (9,13,14,23,(25)(26)(27)(28)(29). In 1923, Silver (5) emphasized the importance of restoring the relationship between the first metatarsal and the sesamoid complex when correcting hallux valgus surgically.…”

PedCAT for Radiographic 3D-Imaging in standing position

“…The medial sesamoid was chosen instead the 1 st metatarsal head because it is regularly closer to the foot sole / ground. The medial sesamoid was chosen instead of the lateral sesamoid because it is less likely to completely dislocate from underneath the 1 st metatarsal head in forefoot deformities such as hallux valgus [23,25].…”