Staging and treatment of osteoblastoma in the mobile spine: a review of 51 cases

Abstract

To define the role of Enneking staging system and of the consequent different treatment options on the outcome of osteoblastoma (OBL) of the spine. A retrospective review of 51 patients with OBL of the mobile spine conducted to compare the outcomes among the different types of treatments at long term follow-up (25-229months, av.90). These 51 patients were previously staged according to Enneking staging system and treatment selected accordingly. 10 stage two (st.2) OBLs were treated with intralesional excision and 41 stage three (st.3) OBLs were treated either by intralesional excision or en bloc resection. The intralesional excision group was divided considering the use or not of radiation therapy after surgery. The recurrence rate was compared among these groups and also considering previous open surgery ("non intact" vs. "intact"). The statistical significance was defined using the Fisher Exact test. No local recurrence occurred in the st.2 patients treated by intralesional excision. Considering the st.3 patients, 2 local recurrences out of 13 patients occurred in the en bloc resection (15.4%) group. All occurred in "non intact" cases (67%). In the intralesional group, 5 local recurrences out of 27 patients occurred (18%) being none in the group that received radiation therapy after surgery. Two occurred in the "intact" (7%) and three in the "non intact" group (75%). Considering all patients, the difference between the recurrence rate between "intact" and "non intact" groups was statistically significant (p<0.002). Intralesional excision proved to be effective in st.2 lesions and en bloc resection in st.3. Radiotherapy seems to be an effective adjuvant treatment when en bloc resection is not feasible or requires unacceptable functional sacrifices. The first treatment significantly affects the prognosis as previously treated patients have worse prognosis.