Figure 1.

Preoperative imagings A; Computed tomography of L4 showing scant bone formation around the granulation tissue and few bony intertransverse bridges between the transverse process and HA. Because of intervening fibrous tissue, contact between HA and the vertebrae is limited (arrowheads). B; Gadolinium-enhanced magnetic resonance imaging (MRI) of L4. Enhancement was observed around transplanted HA (arrowheads), suggesting failure of the posterolateral fusion.