Subperiosteal abscess (SPA) can lead to devastating morbidity and mortality. Prompt management is important; however, the choice of management route is controversial. This study investigates factors associated with surgical management and defines a cut-off abscess volume prompting surgical intervention.

SPA cases presented to King Saud University Medical City (KSUMC) from 2014 to 2023 were reviewed. The surgical approach was studied in association with factors including age, gender, symptoms and signs, laboratory results, computed tomography (CT) characteristics, medications, and surgical approach. Multiple statistical tests were used for analysis, including student t-test, chi-square, multiple logistic regression analysis, and receiver operating characteristic (ROC) analysis.

Patients were managed medically (n = 14, 45.16%) or surgically (n = 17, 54.84%). The average duration of antibiotics was 15 days. Superior SPA favors surgical management (OR = 6.722, CI [1.332–33.913], p = 0.029), along with the use of steroids (OR = 5.625, CI [0.915–34.572], p = 0.049), and abscess volume (OR = 10.003, CI [1.418–70.540], p < 0.001). However, the only factor attributing to a surgical decision on multivariate logistic regression analysis was abscess volume (OR = 5.126, CI [1.023–25.694], p = 0.047). SPA volume of ≥ 0.648 ml strongly prompts surgical management, with a sensitivity of 94.1% and a specificity of 71.4% (p = 0.000).

SPA volume increases the likelihood of surgical intervention by five times, especially when abscess volume is ≥ 0.648 ml.