MRI FOR PLANTAR FASCIA: TEARS, FASCIITIS AND ANATOMY

We’re going to look at MRI of the plantar fascia again, and in today’s video, we’re going to just focus on the MRI appearance of the various bands of the plantar fascia. There are three of them, two of which are more important. The most common area on MRI to see plantar fasciitis or plantar fascia tears, is going to be the central band, so we’re going to look in this video at the anatomy and how to separate out these three bands. We’re going to go over the plantar fascia and look at the normal anatomy, and the normal appearance of the plantar fascia.

The plantar fascia is basically an aponeurotic thickening, which is very important in maintaining the longitudinal arch of the foot, and it attaches proximally to the calcaneus. As it goes distally, it breaks up into three bands: there’s a central band, a medial band, and a lateral band, and the most important one is the central band, as this is the thickest and largest of them. It actually lies more medially on the calcaneus than centrally, but this is called the central band, and we have the lateral band out here. The central band lies deep to the flexor digitorum brevis muscle.

So, the flexor digitorum brevis lies deep to that, and as it continues distally in the foot, it eventually breaks up into five bands, which go towards the toes. They’re not that important for us in terms of assessment. Our main assessment is going to be proximally in the foot. The lateral band lies deep to the abductor digiti minimi, and this band inserts onto the base of the fifth metatarsal. So, this is the insertion of the base of the fifth metatarsal, and if we look at it on the axial scans, this is the insertion side of the lateral band of the aponeurosis, and it lies fairly close to the insertion side of the peroneus brevis. This is the peroneus brevis here. The peroneus brevis inserts more laterally, more superiorly onto the base, and the plantar aponeurosis, a lateral band, inserts more centrally and at the inferior margin.

The medial band is not something you really need to worry too much about. It’s a pretty thin band, and you don’t tend to see any abnormalities of it. It lies superficial to the abductor hallucis, so this is the abductor hallucis here, and it lies on the superficial margin of it.