Novel Ultrasound Anatomical Measurement of the Deep Transverse Metatarsal Ligament: An Intra-Rater Reliability and Inter-Rater Concordance Study

Abstract

Insufficient space below the Deep Transverse Metatarsal Ligament (DTML) could be an etiological factor for Morton’s Neuroma (MN). To date, there is a lack of studies measuring the space below the DTML. For this reason, this study assesses the intra- and inter-rater concordance and reproducibility of measurements of the space below the DTML between the third and the fourth metatarsal heads (M3 and M4) using ultrasound imaging to assess and verify the reliability and reproducibility of measurements of the space under the DTML. Forty feet from twenty patients were examined using ultrasound by three trained evaluators at two different times. The two measurements taken on each foot were: base (b)—distance between M3 and M4, and height (h)—distance between the DTML and the plantar skin surface. This was a quantitative, observational, analytical study. The concordance rate between observers for measurements of height and base were 98.5% and 99.5%, respectively. The mean area obtained of the space was 54.6 mm2 and 57.2 mm2 for both the left and right foot (p > 0.05). Reproducibility over time calculated in pre- and post-measurements showed an intraclass correlation coefficient of 1.00 (95%CI: 0.99–1.00), which leads us to conclude that the measurements are perfectly reproducible. Both measurements (height and base) of the space under the DTML, performed by ultrasound, are reliable and reproducible.

Study of the Anatomical Association between Morton’s Neuroma and the Space Inferior to the Deep Transverse Metatarsal Ligament Using Ultrasound

“…Other studies have used US for the diagnosis and evaluation of NM, but none have metrically analyzed the anatomical structures related to NM [ 1 , 7 , 8 , 9 , 10 , 11 ]. In addition, our study adds the clinical advantages of using US [ 19 ], through a protocol that we evaluated in a previous work that obtained a concordance of 99.58%, thus guaranteeing the measurements [ 6 ]. All this guarantees that the evaluations of the new measurements (h, b) studied with US have been carefully verified, with the opinion of two evaluators.…”

“…The anatomical US measurements below the DTML followed the same examination protocol. A preliminary examination protocol was carried out with the US, in which the probe was pressed on the plantar area both in the transverse position or short axis and in the longitudinal position or long axis to locate the DTML [ 6 ].…”

“…There are studies which link this compression with the development of MN, and, on the other hand, there are studies that describe the diagnosis of NM through the use of US, as well as the ultrasonic anatomical description [ 1 , 4 , 6 , 7 , 8 , 9 , 10 , 11 ]. Nevertheless, none has measured the anatomical space below the DTML.…”

Infiltrative Type I Collagen in the Treatment of Morton’s Neuroma: A Mini-Series

“…Although specific positive tests for MN are lacking, tenderness associated with touch remains clinical evidence of the presence of Morton's neuroma. However, the support to clinicians deriving from imaging investigations is essential for both the discovery and localization of MN [8]. So far, the diagnostic confirmation of MN's presence is based on two different types of imaging assessments, as well as magnetic resonance imaging (MRI) and ultrasound (US).…”