I admit treatment outcomes for sesamoid
fractures can be perplexing, and in some cases,
less than ideal. Physiologic reasons exist.
Previous literature discusses off-loading, PT,
injections and removal for symptomatic non-
unions. I once read about an ORIF with small
cortical screw placement across a sesamoid
fracture was tried, but never read any long-term
follow up on its success, and whether any other
similar attempts were tried; so, I naturally
assumed the outcome was not very good, and the
surgeon abandoned that particular approach.
From personal anecdotal experience, the
overwhelming majority of sesamoid fractures do
not heal, yet their non-unions tend to remain
relatively asymptomatic, often successfully
managed via off-loading. This is an important
concept to acknowledge when deciding whether to
employ a new treatment for the occasional,
symptomatic non-union.
I tend to incorporate a "Pareto" principle (80-
20 rule) mind set regarding contemplation of a
new treatment, especially for a minority of poor
outcomes. That certainly was not the case when I
advocated cimetidine as a primary treatment for
verrcua back in 1985; There was a need and
significant market to employ a novel, anecdotal
treatment containing evidenced based medicine
for efficacy, in a very active patient
population who simply could not afford to take
the time off required from typical excisions,
especially for "in season" student athletes;
hence its rationale.
Dr. Kass presents an interesting, semi-invasive
treatment proposal: U.S. bone allograft
placement for a sesamoid fracture with electric
bone stimulation. I commend his "outside the
box" thinking, especially given past treatment
outcomes in some cases. On the surface, Dr.
Kass' proposal makes some physiologic sense.
Here are some concerns I'd share: a) I envision
the largest obstacle to allograft incorporation
is the fact that of all pedal bones, the blood
supply to the sesamoids is the poorest.
Given that, my hunch is the overwhelming
majority of allografts would not successfully
incorporate with the host bone; b) The graft-
host interface surface area is very small,
another detriment to osteoinduction/conduction.
c) post graft placement, do you keep the patient
non-weight bearing 8 weeks to allow time for
graft incorporation? How practical is this for a
sesamoid? d) Suppose the allograft stimulates
fracture healing, how does a clinician control,
even eliminate heterotopic bone from forming
along the dorsal and/or plantar surface of the
sesamoid? The former would ultimately interfere
with its gliding mechanism and likely create
degenerative arthritis of that articulation; the
latter could create a painful plantar spur which
might necessitate remodeling; e) electric bone
stimulation works best when an adequate blood
supply exists. It doesn't work at all in pseudo-
arthroses, and is less successful in atrophic
non-unions.
Should a clinician expect EBS to work given the
sesamoid's blood supply? f) If not, as another
alternative, would placement of a cortical screw
along with the allograft stimulate primary bone
healing and prevent this potential complication?
Isn't that impractical considering a sesamoid's
size, small graft interface, and blood supply?
g) If actually tried, now this treatment becomes
invasive. Doesn't that defeat your original
intended purpose for a conservative attempt?
These are some of the concepts/questions one
must evaluate prior to undertaking a new
proposed treatment. We should have some
obligation to incorporate the 80-20 rule. Is
this all worth trying to treat a
minority of poor results?! Strictly from the
philosophical standpoint of attempting another
measure of conservative care...perhaps.
Ultimately, one must question practicality,
anticipated efficacy of graft incorporation, and
associated out-of-pocket expenses, i.e., a)
graft material procurement, and b) ultrasound
guidance technical component. If someone does
try this novel and innovative approach, I'm very
curious to learn whether the graft incorporates
and whether any of the aforementioned adverse
sequellae occur.
Barry Mullen, DPM, Hacketstown, NJ,
yazy630@aol.com
