Application of Indocyanine Green Angiography for Closed Operative Calcaneus Fractures

Fractures of the calcaneus comprise 2% of all adult fractures. These fractures make up 60%
of all tarsal injuries, the majority of which are closed, displaced intra-articular
fractures. Despite the injury's prevalence, dispute over the appropriate method of treatment
remains ongoing. Several studies have shown that an open, surgical approach is superior to
either a non-surgical or percutaneous approach with regard to restoring proper alignment and
structure of the hindfoot, depending on the severity of the displacement, and provided that
certain patient conditions do not preclude surgery. Adequately restoring hindfoot structure
is paramount to good clinical outcome; not only is proper alignment integral for fully
recovering physiological functionality, but also in preventing further complications such as
subtalar arthritis that present commonly in malunited calcaneal fractures.

Though literature may show that open reduction and internal fixation (ORIF) techniques
provide a better long term outcome of severely displaced intra-articular fractures,
proponents of both non surgical and percutaneous approaches argue that the superiority of
the outcome may be mitigated by the fact that open surgical procedures are laden post
operatively with numerous wound complications. These complications include, but are not
limited to, both deep and superficial infections resulting in slough, dehiscence, necrosis,
and erythema in and around the surgical site. Managing infections of the surrounding soft
tissue and vasculature of the calcaneus following operative treatment indeed seems to
present a great challenge to treating physicians, with wound healing complications present
in 2-25% of cases.

A necessity for surgical wound repair is adequately vascularized tissue, which can be
difficult to come by during closure of the wound due to the undermining and displacement of
soft tissue during surgery. Sufficiently perfused soft tissue can also be difficult to
differentiate from tissues that are inadequately vascular based on traditional clinical
criteria such as color, warmth, and dermal bleeding. The degree of this avascularity can
depend on many factors relating to the patient, necessitating studies be conducted
identifying what factors place a prospective patient at a higher risk for developing wound
healing problems post operatively. Studies of this nature thus far have noted that factors
such as age, sex, height, weight, Bohler's angle, tobacco usage, and pre-existing conditions
such as diabetes, vascular disease, and immune deficiencies may be indicative of increased
likelihood for developing post surgical complications. Another risk factor of particular
interest is the timing of surgery after the incidence of injury. Current literature
regarding treatment of hindfoot injuries shows a moderate degree of uniformity, advocating a
delay in operative measures until the soft tissue swelling around the injury has had time to
subside: a window of approximately 7-14 days after injury. Additionally, in their
investigation of Bohler's angle as a predictor for wound healing complications, Shuler and
colleagues noted the pre and post operative Bohler's angle differential to be a significant
predictor of developing infections, postulating that the increase in heel height during
surgery may concomitantly increase soft tissue tension substantially enough to disrupt
proper blood supply to the surgical site during healing. These findings lend tremendous
support to the idea that blood perfusion in soft tissue plays a significant role in
predicting wound healing complications. However, to our knowledge, the use of angiography to
correlate pre and post operative soft tissue perfusion patterns with post operative
complication in patients undergoing ORIF of fractured calcanei has never been investigated.

Indocyanine green (ICG) angiography has been utilized in a myriad of other fields of
medicine to evaluate perfusion in different tissues. It has been used in cardiac surgery to
asses bypass patency, in microsurgery to assist in free tissue transfers, and in plastic
surgery to assess areas of future necrosis during mastectomy operations. Recently, ICG
angiography has been used in general surgery to detect ischemic tissues and aid surgeons in
determining the appropriate extent of debridement necessary prior to wound closure in
laparotomy procedures. Though its utility in other disciplines of medicine are currently
being further developed and understood, the implications of ICG angiography in orthopaedic
surgery have gone unrecognized. We postulate that soft-tissue perfusion patterns elucidated
by ICG angiography in the heels of patients that have incurred calcaneal fractures may be
predictive of wound healing complications that develop after surgery. This information could
allow surgeons to greatly reduce the complication rate of open reduction procedures on
calcaneus fractures by early utilization of appropriate, patient specific prophylactic
measures, and could provide an additional contraindication to this operation for patients
whom otherwise were not aware they are at an elevated risk.

Inclusion Criteria:

- Persons 18-65 years of age with closed unilateral operative Calcaneus fractures that
may be approached by an extended lateral incision

Exclusion Criteria:

- Patients declining participation

- Patients with vascular disease or injury requiring vascular repair

- Patients that have undergone prior ankle or hindfoot surgery

- Patients with additional hindfoot injury or injuries

- Patients with open calcaneal fracture

- Patients with head injury

- Patients with injury greater than 3 weeks old

- Patients who are pregnant or currently nursing

- Patients who are incapable of personally understanding the informed consent document
due to mental incapacitation or inability to speak and understand English.