Distribution of the subtendons in the midportion of the Achilles tendon revealed in vivo on MRI

Abstract

The aim of the study was to check if the subtendons of the Achilles tendon can be identified in vivo on MRI in the midportion of the tendon. The relation of the plantaris tendon to the Achilles tendon was also examined. A retrospective study of 200 MRI of ankle joints including the Achilles tendon was conducted. Statistical analysis of the correlation between the possibility of identifying the subtendons and the side, gender, presence of the central soleus tendon and plantaris tendon variation was performed. The inter-observer agreement between two reviewers in their evaluation of the subtendons was assessed using kappa statistics. The subtendon from the lateral head of the gastrocnemius muscle was identified in 65% (k = 0.63) and was located in the anterior part of the Achilles tendon. The subtendon from the soleus muscle was recognized in 12% (k = 0.75) comprising anterior part of the tendon. In 6% the subtendon from the medial head of the gastrocnemius muscle was identified (k = 0.58). The central soleus tendon was identified in 85% of cases. Statistical analysis shows the weak correlation of the presence of the central soleus tendon and the possibility of identifying the subtendon from the soleus muscle. The plantaris tendon was directly related to the insertion of the Achilles tendon in 42.5%. Identification of the subtendons of the Achilles tendon on MRI is challenging, and most often it is only possible to find the subtendon of the lateral head of the gastrocnemius muscle.

The twisted structure of the fetal calcaneal tendon is already visible in the second trimester

“…In contrast to the adult calcaneal tendon, the twisted structure of the calcaneal tendon in fetuses has not been investigated in detail. The aponeuroses located on the surfaces of the triceps surae muscle extend downward, forming twisted subtendons [33,35]. In the soleus muscle, the aponeurosis joins anteriorly the inconsistent central tendon, significantly increasing the area of muscle fiber attachment [2].…”

The Flexor Retinaculum Connects the Surrounding Structures into the Medial Ankle Complex

“…The retinaculum proprioception effect was used in the surgical transfer of the inferior extensor retinaculum (IER) to augment the superior peroneal retinaculum [1]. Diversified collagen fiber systems within the fascia, the ligament, or the tendons [4] enable several functional units to be combined into one anatomical structure [5].…”

MRI of the Achilles tendon – a comprehensive pictorial review. Part two

“…Most partial surface tears may be related to tendon degeneration. Most of them have a vertical orientation and are located in the dorsal part of the tendon, affecting the subtendon from the medial head of the gastrocnemius [ [39] , [40] , [41] , [42] ]. Intratendinous defects are located mainly in the anteromedial part of the tendon, affecting mostly the subtendons from the lateral caput of the gastrocnemius and soleus muscles.…”