En-Bloc Resection and Instrumented Reconstruction of Primary Tumors and Solitary Metastasis of the Spine**

INTRODUCTION: Primary tumors of the spine and with limitations solitary metastasis are indications for extralesional resection (en-bloc) to avoid local recurrence and further metastasis. In most tumors, especially osteosarcoma and Ewings sarcoma, additional neoadjuvant therapeutic modalities are of utmost importance for patient outcome.

MATERIAL AND METHODS: Within the last 5 years we performed 14 en-bloc resections followed by instrumented reconstruction using a posterior multisegmental internal fixator and a modular tumor cage or fibula struts anteriorly. Surgical staging and planning was performed according to the system of Boriani, Weinstein and Biagini (1997). There were 3 osteosarcoma, 3 chondrosarcoma, 4 Ewing sarcoma, one desmoblastic fibroma and one solitary metastasis in a soft tissue sarcoma, a paraganglioma and a thyroid carcinoma each. In 12 cases one vertabra was resected and in one case each 3 and 4 vertebrae. Minimum follow- up is 2 years in all patients (2-5 years)

RESULTS: In all except 3 patients (2 osteosarcoma, 1 chondrosarcoma) the extralesional approach was confirmed histologically. The patient with 4 vertebrae resected en-bloc (osteosarcoma) suffered from anterior spinal artery syndrome, which improved within the first postoperative year. This was the only early complication. The 2 osteosarcoma patients had a poor response grade (Grade 5), local recurrence and distant metastasis and died (6 months and 2 years postop.). The patient with soft tissue sarcoma metastasis died of distant metastasis 18 months postop. All other patients are alive and without signs of local recurrence or distant metastasis. All Ewings sarcoma patients had a good response grade (Grade 1 and 2). One pseudarthrosis 1 year postoperatively was successfully repaired with posterior revision.

CONCLUSION: The possibility of extralesional en-bloc resection (wide or marginal) of spinal tumors depends on tumor size and location. Extralesional resection has a strong positive influence on patient outcome. In osteosarcoma and Ewings sarcoma the response grade on preoperative chemotherapy and additional radiation in Ewings sarcoma also has a strong influence on outcome. The worst prognosis is associated with intralesional approach and poor response grade. Instrumented primary stable reconstruction is routinely possible.

LITERATURE: Boriani S, Weinstein JN, Biagini R: Spine update - primary bone tumors of the spine. Terminology and surgical staging. Spine 22 (1997) 1036-1044

** The FDA has not cleared a drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed in an “off-label” use).