Long-term outcomes and postoperative adjacent segment degeneration following lumbar fusion in elderly patients

Objective To evaluate the long-term clinical outcomes and postoperative adjacent degenerative segments( ASD) after lumbar fusion in elderly patients. Methods From M arch 1999 toJune 2006,83 patients over 60 of age with lumbar degenerative disease were treated by posterior lumbar fusion in our hospital. The correlations of ASD occurrence with gender,range of fixation,position of fixation,"floatingfusion ",and preoperative adjacent disc regeneration were analyzed.Results All patients were followed up for 84-127 months with a mean of 104. 7 months. Radiographic ASD occurred in 28. 9%( 24 of 83) of patients including18 cases were noted that ASD occurred proximal tothe prior fusion and 6 patients distally,respectively. Fusion of L1-L3 proximally and preoperative adjacent disc degeneration increased the risk of ASD,while gender,range of fusion and"floatingfusion"were not the risk factors. Patients with radiographic ASD had worse Oswestry disability index( ODI) and Japanese Orthopedic association scores( JOA) at last follow-up than those without ASD( P 0. 05). Conclusion Preexistingadjacent disc degeneration is a significant risk factor of ASD in lumbar spine. Fusion up toL1-L3 increases the risk of ASD when compared with L4 and L5. Long-term clinical outcome after lumbar spine fusion is negatively influenced by ASD.