Three-dimensional evaluation of postoperative swelling in treatment of zygomatic bone fractures using two different cooling therapy methods: a randomized, observer-blind, prospective study

Abstract

Background: Surgical treatment and complications in patients with zygomatic bone fractures can lead to a significant degree of tissue trauma resulting in common postoperative symptoms and types of pain, facial swelling and functional impairment. Beneficial effects of local cold treatment on postoperative swelling, edema, pain, inflammation, and hemorrhage, as well as the reduction of metabolism, bleeding and hematomas, have been described.The aim of this study was to compare postoperative cooling therapy applied through the use of cooling compresses with the water-circulating cooling face mask manufactured by Hilotherm in terms of beneficial impact on postoperative facial swelling, pain, eye motility, diplopia, neurological complaints and patient satisfaction.

Methods: Forty-two patients were selected for treatment of unilateral zygomatic bone fractures and were divided randomly to one of two treatments: either a Hilotherm cooling face mask or conventional cooling compresses. Cooling was initiated as soon as possible after surgery until postoperative day 3 and was applied continuously for 12 hours daily. Facial swelling was quantified through a three-dimensional optical scanning technique. Furthermore, pain, neurological complaints, eye motility, diplopia and patient satisfaction were observed for each patient.

Results: Patients receiving a cooling therapy by Hilotherm demonstrated significantly less facial swelling, less pain, reduced limitation of eye motility and diplopia, fewer neurological complaints and were more satisfied compared to patients receiving conventional cooling therapy.

Conclusions: Hilotherapy is more efficient in managing postoperative swelling and pain after treatment of unilateral zygomatic bone fractures than conventional cooling.

Trial registration: German Clinical Trials Register ID: DRKS00004846.

Figure 1

The coronal view of a 24-year-old patient shows an isolated zygomatical fracture on the right side. Red arrows demonstrate the fracture lines.

Figure 2

Three-dimensional reconstruction of postoperative cone beam computed tomography after osteosynthesis of a right-side zygomatical fracture, along the frontozygomatic suture, infraorbital margin and zygomatico maxillary buttress.

Figure 3

Front view (A) and lateral view (B) of a patient wearing the Hilotherm mask.

Figure 4

The final three-dimensional output of the Slim3D software is a triangulated polygon mesh, visualized as a synthetically shaded representation. Three-dimensional optical scans were recorded during six time points: T1 (day 1 after surgery, mask not shown), T2 (day 2 postoperatively, yellow mask), T3 (day 3 postoperatively, red mask), T4 (day 7 postoperatively, green mask), T5 (day 28 postoperatively, mask not shown) and T6 (day 90 postoperatively, blue mask). The reference three-dimensional model of each patient was T6. An individual mask of the midface of each patient was created and aligned to all captures and the difference in volume was thereby calculated.

Figure 5

The amount of swelling (ml) in both groups at different time points is shown. On postoperative days 1, 2 and 3, a significant downregulation of swelling could be achieved by cooling with Hilotherm compared to conventional cooling. This trend was maintained on postoperative day 7. After 28 days no differences with respect to swelling could be seen between groups.

Figure 6

Pain was calculated in terms of a visual analogue scale from subjective analysis ranging from 0 to 10. A significant increase in pain was reported in the conventional group compared to the Hilotherm group during postoperative days 1 and 2. The pain intensity was no different between groups on postoperative day 7.

Figure 7

Reduction was seen in the Hilotherm group in the neurological score at postoperative day 1, but no differences were detected after 7, 28 and 90 days between groups.

Figure 8

The overall satisfaction was significantly lower in patients receiving conventional therapy compared to patients receiving cooling therapy by Hilotherm.