Question: what does it mean to fuse the spine
[{'answer': 'joins two or more vertebrae', 'provenance': [{'wikipedia_id': '3047799', 'title': 'Spinal fusion', 'start_paragraph_id': 1, 'start_character': 119, 'end_paragraph_id': 1, 'end_character': 146, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'a neurosurgical or orthopedic surgical technique that joins two or more vertebrae'}, {'provenance': [{'wikipedia_id': '3047799', 'title': 'Spinal fusion', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 635, 'bleu_score': 0.979484453366057, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15452879585531294579}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3047799', 'title': 'Spinal fusion', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['Spinal fusion, also called spondylodesis or spondylosyndesis, is a neurosurgical or orthopedic surgical technique that joins two or more vertebrae.', 'Spinal fusion, also called spondylodesis or spondylosyndesis, is a neurosurgical or orthopedic surgical technique that joins two or more vertebrae', 'Spinal fusion, also called spondylodesis or spondylosyndesis, is a neurosurgical or orthopedic surgical technique that joins two or more vertebrae.']}}]}]