The treatment of aneurysmal bone cysts (ABCs) of the spine remains controversial in the literature. Treatment options have included radiation, curettage and bone graft, extirpation, and various combinations of these. Conspicuously missing in previously published articles and texts are guidelines for dealing with the instability and deformity that often accompany ABCs of the spine. The index case in this report highlights the potentially devastating effects of treating the tumor in isolation without addressing the concomitant deformity and instability. The status of the structural integrity of the spine must be assessed before initiating treatment. If instability or deformity or both are already present or if the amount of osseous tissue to be resected may render the spine unstable, then instrumentation and fusion should be performed at the time of surgical resection or before other forms of therapy. We present three cases of ABCs of the spine in which the tumor itself was treated with surgical extirpation and the associated deformity and instability were treated with spinal instrumentation and long fusions.