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This is a 31M with chronic pain.
DPM asked to “rule out accessory navicular”.
I suppose he saw a radiographic abnormality, but I don’t have XR to review.
Is this some bizarre form of a non-osseous coalition?
The irregular ossification is interposed between the superomedial and
inferoplantar longitudinal components of the Spring Ligament complex.
Can this be old post traumatic heterotopic ossification of the
medioplantar oblique-calcaneonavicular ligament?
There is no accessory navicular and the PTT is normal, though there is mild
tenosynovitis.
I received several answers.
A couple of you suggested a combination of “congenital” variant plus
non-osseous fusion.
Someone specified os secondarius…but that is more lateral, and can be
confused with a non-united anterior calcaneal process fracture…
the ossification in this case is plantar medial in the region of the
anterior subtalar joint adjacent to the medial-mid navicular base.
Both Paulo Dolabela Vasconcelos and Caio Nery suggested that this could be
related to an osteochondroma…which seems a possibility.
Paulo shared an article (attached) that would classify this (if it is) in
the spectrum of Trevor Disease…which I found very confusing.
I would vote for this being an unusual coalition as I do not see definite
continuity of the marrow containing area and the underlying bone. Having
said that a fractured osteochondroma such that the continuity was disrupted
would be difficult to exclude. One would expect possible additional sites
for Trevor disease so radiographs of the knee and ankle might be useful.
I have seen a recent similar case and was in the same dilemma. It was
resected and difficult to differentiate these even on path review as it
just looked like mature bone fragments. I would recommend CT as it might
better depict the osseous alterations. However, I doubt any of this will
change need for resection and maybe packing area with fat.
I am confused by what seems to be variable terminology in the literature
for intra-articular osteochondral bodies…..ranging from “intra-articular
osteochondroma, to extraosseous intra articular osteochondroma, to synovial
osteochondroma” and I asked Mark to clarify.
He answered:
Yes this terminology is confusing at best. I am not a big fan of the term
synovial or soft tissue osteochondroma as the term osteochondoma should
mean that there is continuity with the underlying bone cortex and marrow.
Pathologists sometimes use this term as it describes what is seen
pathologically. Many of these represent soft tissue chondromas with
extensive metaplastic ossification including the development of an
extensive yellow marrow space. Another consideration here is an
osteochondral fragment related to a coalition or degenerative disease.
I agree that it would be nice to see CT, though I’m not sure it will affect
management. This should be resected regardless.
I will try to contact the referring podiatrist and see if I can get follow
up.
Hilary
PS The Video of yesterday’s OCAD Lecture “Extreme Metastases” by Dr. Rob
Ashford of Leicester Hospital, UK is now available on demand in the video
section of our website at ocadmsk.com
We just had an excellent Case Conference (OCAD-Rio MSK) this morning, Focus
on Sports Imaging….that video will be made available on the site,
probably this weekend.
On Tue, Feb 23, 2021 at 12:04 PM hilary umans <hilary.umans@gmail.com>
wrote:
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Apologies…I forgot to attach the (open access) article Paulo shared
on Trevor Disease.
On Fri, Feb 26, 2021 at 11:55 AM hilary umans <hilary.umans@gmail.com>
wrote:
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