Clinical characteristics and treatment options for two types of osteoblastoma in the mobile spine: a retrospective study of 32 cases and outcomes.

PURPOSE: A retrospective study of 32 patients with osteoblastoma (OBL) in the mobile spine was performed to analyze the clinical characteristics of two types of spinal OBL. We also aimed to find influential factors for OBL in the mobile spine.

METHODS: Between 2002 and 2011, 32 patients with either conventional osteoblastoma (CO) or aggressive osteoblastoma (AO) in the mobile spine were treated in our center. All patients were treated with either total excision or subtotal excision + postoperative radiotherapy. The mean follow-up was 45.8 (18-128) months. Clinical data and surgery efficacy were analyzed to search for clinical characteristics of two subtypes of spinal OBL and discuss the possible factors influencing relapse.

RESULTS: There is significant difference between CO and AO in tumor size (p < 0.0005), preoperative alkaline phosphatase (ALP, p < 0.0005) and intraoperative blood loss (p = 0.013). Multivariate logistic regression was used to find the influential factors for relapse and the results were: preoperative ALP, b = 0.023, p = 0.029; surgery protocol, b = -7.597, p = 0.007; tumor size, ≥3/<3, b = 24.805, p < 0.0005; age, b = 0.054, p = 0.632; and pathology type, b = 1.998, p = 0.34.

CONCLUSIONS: Tumor size, preoperative ALP and CT images were helpful for distinguishing AO from CO. The difference in intraoperative blood loss between CO and AO is mainly attributed to the size of the lesion. Preoperative ALP, surgery protocol and tumor size (≥3/<3) were considered to significantly influence relapse of spinal OBL.