Incidence of osteitis of the paranasal sinuses in chronic rhinosinusitis

Osteitis of the paranasal sinuses (PNSs) is considered as a manifestation of chronic rhinosinusitis (CRS), but its prevalence and clinical manifestations remain poorly studied. Objective. To evaluate the incidence and severity of osteitis of the PNSs in patients with CRS. Patients and methods. A retrospective analysis of 300 computed tomography (CT) scans of the PNSs was performed. The study included 44 patients with a history of PNS surgery and 256 patients without it. Among them, 90 (30.0±2.6%) patients had a form of the disease with nasal polyps, and 210 (70.0±2.6%) — CRS without them. The prevalence of pathological changes in the PNSs was assessed using the Lund-Mackay staging system, and the severity of osteitis was evaluated using the Global Osteitis Scoring Scale (GOSS). The Mann-Whitney U test and Pearson’s χ2 test were used to compare groups. Results. In the total sample, osteitis was detected in 34 patients (11.3±1,.8%). Among patients with nasal polyps, osteitis was found in 27 out of 90 (30.0±4.4%), while among patients without polyps — in 7 out of 210 (3.3±1.2%; p<0.001). Among 44 patients with a history of surgical interventions on PNSs, osteitis was diagnosed in 18 (40.9±7.4%) cases, among 256 non-operated patients — in 16 (6.3±1.5%; p<0.001). In terms of the number of lesions of the PNSs (106 cases), osteitis of the ethmoid cells (59 cases; 55.6±4.8%) and maxillary sinuses (41 cases; 38.7±4.7%) was predominant; it was less common in the sphenoid (4 cases; 3.8±1.9%) and frontal sinuses (2 cases; 1.9±1.3%). In patients with CRS with osteitis, a clinically insignificant degree (GOSS<5) was more often recorded — in 21 (61.8±8.3%) cases; mild (GOSS 5—20) — in 11 (32.4±8.0%); moderate (GOSS 21—35) and severe (GOSS>35) degrees accounted for 1 case each (2.9±2.9%). In the group of patients with osteitis, the median score on the Lund-Mackay staging system was 9.0, and in the group without osteitis — 7.0; the differences were borderline and did not reach the level of statistical significance (U=5408.0; p=0.05). In patients with clinically significant osteitis, the median Lund-Mackay score was statistically significantly higher and amounted to 14.0 points compared to 7.0 points in the group without osteitis (U=2445.5; p=0.010). Conclusion. Osteitis of the walls of the PNSs, as detected by computed tomography, is revealed in approximately one in ten patients with CRS, significantly more often in persons with past history of surgery. In patients with CRS, the presence of nasal polyps is associated with a higher incidence of osteitis, which indicates a possible role of nasal polyps as a risk factor for the involvement of the PNS bone structures. Clinically significant osteitis is associated with greater severity of pathological changes in the PNSs on CT, which requires further study of its role in the course and outcomes of CRS.