A Radioanatomical Evaluation of the Plantaris Tendon with Magnetic Resonance Imaging Method and a Review of the Literature in the Light of Our Findings

Abstract

Introduction: Variations of the plantaris muscle and tendon are common. Ultrasonography and magnetic resonance imaging (MRI) are radiological methods for evaluating the plantaris tendon. This study aimed to perform a radioanatomical evaluation of the plantar tendon using MRI and to compare our findings with the literature data. Materials and Methods: The presence of the plantaris tendon in 155 ankle magnetic resonance studies of 139 patients, its diameter, its course, the localization of the calcaneal attachment of the tendon, and its relationship with the Achilles tendon were evaluated. Student’s t-test was used for those with normal distribution in numerical data, and the Mann–Whitney U test was used for those who did not. Pearson Chi-square test was used in the evaluation of categorical data, depending on the assumptions. P <0.05 was considered statistically significant. Results: A total of 139 patients, 89 (67.74%) females, and 50 (32.26%) males were included in the study. In 115 (74.2%) of 142 cases in which the plantaris tendon was imaged, the plantaris tendon was inserted into the calcaneus separately from the Achilles tendon and was joining the Achilles tendon at various levels in 27 cases (17.41%). In 27 cases where the plantaris tendon joined with the Achilles tendon, the distance from the junction point to the calcaneal insertion was 15 ± 9.90 cm. Conclusion: Our study is one of the limited number of studies in the literature to examine the thickness and termination levels of the plantaris tendon. We believe that our measurements will contribute to future radioanatomical meta-analyses.