Prognostic Factors Influencing Survival and Oncological Outcome in Patients with Parosteal Osteosarcoma

This study aimed to evaluate the significance of radiological (magnetic resonance imaging [MRI]) findings, surgical, and previous interventions on prognosis with oncological and functional outcome in patients with parosteal osteosarcoma (POS). Twenty-seven patients (8 male/19 female) who were operated with the diagnosis of primary POS in our institution were retrospectively reviewed. The epidemiological data, biopsy method, misdiagnosis/improper interventions, and delay in diagnosis were noted. The lesions’ maximum circumferential extension, maximum longitudinal extension, intramedullary involvement, and neurovascular extensions in MRI sections were evaluated, and the resection type (segmental intraarticular/segmental intercalary/hemicortical), reconstruction type (biologic/non-biologic), and surgical margins were noted. Functional and oncological results at the last follow-up were assessed. The mean age was 31.6 (12–73) years, and mean follow-up was 80.8 (24–270) months. Intramedullary involvement percentage was related with maximum circumferential extension percentage and maximum longitudinal extension. (p = 0.006, p = 0.005) The intramedullary involvement ratio of ≤ 10