the mythical Knot of Henry

does the Knot of Henry really exist? It is described in Last's Anatomy and other texts, but what does it really look like?
Here is a fresh cadaver dissection of a Knot of Henry on a right foot:





Because I am a Luddite and cannot work out how to label this photo and post it as well, it appears 'native'. If you click on the photo it should come out in full resolution.
The tendon held in the artery clip is Flexor Digitorum Longus, FDL, the 'Dick' in 'Tom, Dick and Harry'. Unfortunately this mnemonic leaves out 'Artery, Nerve' and should be T,D,A,N,H.
the Tibial Artery and Nerve are in the Tarsal Tunnel, between FDL anteriorly and FHL (Beef to the Heel) postero-laterally.
In this photo, the very upper-right corner of the photo is the medial malleolus, and the largest, most superior tendon is Tibialis Posterior inserting onto the navicula (Latin, 'little boat') bone, immediately above the tip of the artery clip.
More distally, to the left of the artery clip, the FDL tendon decussates over the FHL tendon, but is at the same time adherent to FHL. This is the Knot/Master Knot of Henry. Not really a Knot at all, but more reminiscent of the way FDS decussates around FDP in the fingers, except that in this Knot there is attachment as well.
The significance is that sectioning FDL above the knot allows FHL to still give some flexion to the lesser toes (eg: if harvesting FDL for a Tib Post reconstruction).
In vivo (in other words, operating), there is a leash of veins that usually needs careful diathermy, and which sits immediately anterior (above, in this picture) the knot. That is, plantar to the naviculocuneiform joint between it and the knot, in the shadowed gap in this picture.

introduction

This blog is intended as a resource and point of contact for orthopaedic fellows and trainees for accessing foot and ankle information. It is not intended as a point of referral for members of the public, nor is it to be seen as a definitive textbook.

It is being started by two friends and colleagues, Al Marsh and Al Dray, from UK and NZ respectively, as a way of posting high-pixel clinical photos for their registrars to view (rather than swamp individuals' emails with these large files), and post interesting cases/Xrays for discussion.
We hope it will grow in time to be a useful resource for trainees coming up to their final fellowship exams - the subspecialty area of Foot and Ankle is not always well-understood at this stressful time.

We make no undertaking to make regular posts, but hope that if it is successful it will gain a life of its own. The intention is to be helpful, but there is no substitute for doing your own reading/learning and seeking teaching from your consultants as you go.