TTC & Hindfoot Fusion | Case Report – DynaNail® TTC Fusion System TTC And Hindfoot Fusion Case Report DynaNail TTC | Page 4

Introduction
Achieving fusion using bone graft materials has proven challenging in high-risk patients with degenerative
bone conditions or who are immuno-compromised. A study by Jeng et al. reported a 50% non-union rate
in patients who underwent TTC fusions using a femoral head allograft and in particular, no fusions in
diabetic patients. 3
This report presents two cases with diabetic patients who both underwent revision TTC fusion with
Dynanail to treat failed hindfoot arthrodesis.
Performing Surgeon
Dr. L. Daniel Latt, MD, PhD
University of Arizona Medical Center
Tuscon, AZ
Case Report #1
Background Information
The patient, an 80 year old man, former
smoker with diabetes mellitus and a
previous ankle fusion underwent a subtalar
arthrodesis
with
two
headless
compression screws. One year after the
procedure, he still had pain in the lateral
hindfoot. X-rays and CT demonstrated a
clear non-union of the subtalar arthrodesis.
Procedure
A revision subtalar arthrodesis was performed. The headless
compression screws were removed, the lateral approach to the
subtalar joint was recreated, and the subtalar joint was
curetted, drilled, and shingled. The arthrodesis site was filled
with cancellous allograft chips mixed with iliac crest bone
marrow aspirate. A 13.5 mm tunnel was drilled through the
calcaneus into the tibia and a 12 x 220 mm DynaNail was
inserted according to the recommended surgical technique.
The Compressive Element was stretched 6 mm before fixating
with screws. A 65 mm headless P-A screw and 45 mm headed
cortical L-M screw were used in the calcaneus. The proximal
and distal tibial cortical screws used were both 25 mm. An
intra-operative X-ray shown to the left reveals the Compressive
Element is stretched 4.5 mm after screw insertion.
3
Jeng CL, Campbell JT, Tang EY, Cerrato RA, Meyerson MS. Tibiotalocalcaneal arthrodesis with bulk femoral head allograft for salvage of large
defects in the ankle. Foot and Ankle International, 2013. 34(9): 1256-1266.
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