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

Paweł Szaro,Khaldun Ghali Gataa,Mateusz Polaczek,Bogdan Ciszek

doi:10.3390/app10227972

Abstract

This study aimed to prove the hypothesis that the medial structures of the ankle are interconnected through the flexor retinaculum’s projections. We conducted a retrospective re-evaluation of 132 MRI examinations of the ankle joint from 57 females and 75 males with an age range of 18–65 and a mean age of 35 years. The correlation between the presence of connections between the flexor retinaculum and the deltoid ligament, the spring ligament, the inferior extensor retinaculum, the paratenon, the fibulotalocalcaneal ligament, the fascia covering the abductor hallucis, and the flexor fibrous sheath were studied. The most common connections of the flexor retinaculum were to the deltoid ligament (97%), the fibulotalocalcaneal ligament (84.1%), and the flexor fibrous sheath (83.3%). Interconnection between the flexor retinaculum and the deltoid ligament correlated with the presence of connections between the flexor retinaculum and the inferior extensor retinaculum, the paratenon, and the spring ligament. Side difference was noticed in connections to the flexor fibrous sheath, the deltoid ligament, the fascia on the abductor hallucis, and the paratenon (p < 0.05). The flexor retinaculum formed a more complex anatomical unit with adjacent structures.

Highlights

The primary function of the flexor retinaculum (FR) is to maintain the tibialis posterior and the flexor digitorum longus tendons to the underlying medial malleolus during the ankle joint movements [1]
This study aims to test the hypothesis that the structures about the medial malleolus connect through the FR, which is a fascial element, and that these connections can be revealed on routine MRI
The first contribution of the present study is that we proved the presence of connections between the FR and the deltoid ligament (DL), the spring ligament (SL), the fibrous sheath of flexors (FFS), the paratenon of the Achilles tendon, the abductor hallucis (AbH), and the inferior extensor retinaculum (IER) in routine MRI ankle examinations

Summary

Introduction

The primary function of the flexor retinaculum (FR) is to maintain the tibialis posterior and the flexor digitorum longus tendons to the underlying medial malleolus during the ankle joint movements [1]. The FR has a stabilizing and mechanical importance, tethering the tibialis posterior tendon, keeping it in the groove, and preventing dislocation [3]. It is an essential element of proprioception, described in the literature as a typical fascial feature [1]. Diversified collagen fiber systems within the fascia, the ligament, or the tendons [4]

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