Foot & Ankle International - 2017 FAI Supplement - 22S

some authors have reported unexplained postoperative pain
and paresthesia over the lateral aspect of the foot despite
hardware removal. The purpose of this study was to determine the contact and injury rate of surrounding anatomic
structures with either the use of the traditional intramedullary
screw (IMS) inserted "high and inside" or a novel intramedullary nail (IMN) inserted "low and outside" through a relative "safe-zone."

Foot & Ankle International, 38(S1)
DOI: 10.1177/1071100717S00019
©The Author(s) 2017

Comparison of Contact and Damage
to Anatomic Structures in the Fixation
of Zone II Fifth Metatarsal Fractures
With an Intramedullary Screw or an
Intramedullary Nail
David Garras, MD, Samuel Adams, MD,
Brian Burgess, DPM
Category: Sports, Trauma
Keywords: Zone II, Fifth metatarsal fracture, intramedullary
nail, safe-zone, high and inside, low and outside
Introduction/Purpose: Percutaneous intramedullary screw
fixation of Zone II fifth metatarsal fractures has become
commonplace. The potential for injury to the important surrounding anatomy has not been well documented, though

22S

Methods: Zone II fifth metatarsal fractures were created in
ten cadaver matched-pairs using a 1mm thick saw through a
small incision. Fractures were randomized to receive either
an IMS or an IMN. The surgical technique was performed in
accordance with the manufacturer's instructions. For the IMS
group, the guide pin was inserted percutaneously according
to the "high and inside" starting point on the base of the fifth
metatarsal using fluoroscopy; followed by insertion of the
3.5mm drill, tissue protector, tap, and screw. For the IMN
group, the guide pin was inserted percutaneously "low and
outside," positioned slightly medial and dorsal to the tip of
the tuberosity of the fifth metatarsal; followed by the 5.2mm
reamer, tissue protector, and IMN. Dissection was performed
to identify damage or contact to the peroneus brevis tendon
(PB), peroneus longus tendon (PL), sural nerve (SN), lateral
insertion of the plantar fascia (PF) and cuboid-fifth metatarsal jointspace.
Results: There were significantly more episodes of PB injury,
PL contact, SN contact, and presence in the cuboid-fifth metatarsal jointspace for the IMS group. There were significantly
more episodes of contact of the PF with the IMN group but no
episodes of damage. The results are summarized in Table 1.
Images of contact and damage are shown in Figure 1.
Fluoroscopic images of the IMN inserted through the "low and
outside" position are shown in Figure 2.
Conclusion: We have demonstrated significant contact and
injury to surrounding structures with the placement of a "high
and inside" IMS for the fixation of Zone II fifth metatarsal
fractures. We believe there is a relative safe zone at the "low
and outside" position that affords less potential damage to the
important surrounding structures. Consideration should be
given to the development of implants inserted through the
relative safe zone.

Foot & Ankle International 38(1S)

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