2.3. Study variables

The primary predictor variable was COVID-19 symptoms before surgery (Table 1 ) [3], which were recorded as binary (AS-COVID vs. MS-COVID).

Severity grades and epidemiology of COVID-19 (in Germany; n > 1.7 Millions) [3], and meta-analytic data with respect to viral shedding [8].

Note: 95% CI – 95% confidence interval.

The main outcome variable was PVS detected in ES/IP (i.e. the inner side of ES in contact with the nasal alar skin, and both sides of IP) removed from the patients (Fig. 1 ), using an NAAT/RT-PCR. This variable was categorical (positive vs. negative on ES/IP). Viral RNA was extracted from the swabs using our previously described method [2]. The primary author (P.P.) performed every surgery (including fracture repair, IP insertion, and ES application), which conformed to suggestions by the AO CMF (https://surgeryreference.aofoundation.org/) and lasted 10–20 min. Intraoperatively, the patients including their mouth, were covered by disposable draping materials (Raucodrape® Abdecktücher, Lohmann & Rauscher GmbH & Co. KG, Rengsdorf, Germany), and the eyelids were closed and held together with 12 mm-wide 3M™ Steri-Strip™ (3 M Deutschland GmbH, Neuss, Germany). After fracture repair, we packed the nares with Merocel® nasal sponge (Medtronic GmbH, Meerbusch, Germany), soaked in the 50/50 mixture of 0.1% oxymetazoline and 2% lidocaine, for a few days, and used an external splint made of Biplatrix® rapid plaster bandage (BSN Medical, Hamburg, Germany) for 7–14 days.

Clinical photograph showing postoperative closed reduction of isolated nasal bone fracture with external nasal splint made of gypsum (yellow star) and intranasal Merocel® packings (red stars).

The other variables were demographic (gender; age), clinical (time to treatment between the COVID-19 cure [please see the three indications of the COVID-19 cure in the section “Study Design and Sample Description”] and operative treatment [days]; length of hospital stay from surgery to discharge [LOS, days]), and operative (lengths of NS/IP [days]) groups.