AOFAS Annual Summer Meeting
June 20-23, 2012
San Diego, Ca.
Mark Hofbauer, DPM
William T. DeCarbo, DPM
Jaytinder Sandhu, DPM
Pittsburgh, Pa
www.theorthopedicgroup.com
Digital Arthrodesis with a One-Piece IntraMedullary Fixation Device: A Retrospective
Review
Mark H. Hofbauer, DPM, FACFAS
My disclosure is in the
Final AOFAS Program Book.
I have a potential conflict with this presentation as I
am on Stryker’s speaker’s bureau
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Correction of lesser digital deformities via proximal
interphalangeal joint (PIPJ) arthrodesis has traditionally
been accomplished with externally placed Kirschner
wires
Although intramedullary devices are available, hesitation
to utilize these devices often centers around concerns of
increased complication rates or the need for hardware
removal
We present a case series where a one piece memory
Nitinol intramedullary fixation device was utilized for PIPJ
arthrodesis
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A retrospective chart and radiographic review of 35 patients with 65
hammertoe implants was performed
Our goal was to assess union rates, complication rates and the need
for hardware removal for all implants in digits two, three and four
Successful fusion was defined by the following parameters:
§  no joint pain, no digital erythema or edema, and radiographic evidence of bony
trabeculation on at least two radiographic views
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Fifth digit implants were not utilized
All procedures were performed by the same surgeon utilizing the
same surgical technique
Post operatively, patients were permitted protective weight bearing in
a surgical shoe for 2-4 weeks
Return to normal shoe gear and full activity is permitted at 4-6 weeks
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Thirty-five patients were
included in this study,
thirty-two females and
three males
Mean follow up time of
27 months (Range 12-40
months; SD: 7)
Mean age was 62.2
years (Range 27-82, SD
12.5)
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Complications were noted
in four patients (6.1%)
§  one asymptomatic non-
union (1.5%)
§  two hardware failures (3%)
§  one implant displacement
(1.5%)
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To date, no patients
required revisional
surgery or hardware
removal
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Several methods for PIPJ fusion when correcting digital
deformities have been described in the literature including use
of k-wires, silicone implants, allograft bone, stainless-steel
wire suture, titanium screws and absorbable screws
Our focus in this study was to evaluate the efficacy of a onepiece memory Nitinol intramedullary fixation device to correct
digital deformities
Implantable devices offer both one and two-component
options
Success rates for these devices have been reported to range
from 54-97%
With one-piece implants, fusion rates have been reported at
93% with no additional surgeries or implant removal required
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In our experience, utilizing a one piece memory Nitinol
intramedullary internal fixation device for PIPJ arthrodesis
provided a success rate of 93.8%, which is comparable to
previously reported rates
Despite having a 6.1% complication rate, none of our patients
required a second procedure or removal of hardware
There are limitations in our study
§  This is by design a retrospective analysis which is therefore inherently
limited in application
§  In addition, future research is needed to evaluate if fusion rates vary or
are dependent on which digits (two, three or four) are being addressed
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The authors suggest an intramedullary approach
for PIPJ arthrodesis when faced with digital
deformities
In our experience a one-piece memory Nitinol
intramedullary fixation device offers low
complication rates, does not require removal,
provides a cosmetically appealing alternative to
fixation with percutaneous K-wires and avoids
potential pin track complications
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