Outcome of Salvage Lumbar Fusion after Lumbar Arthroplasty

STUDY DESIGN Retrospective review. PURPOSE This study aims to define the role of lumbar fusion for persistent back pains after the lumbar disc replacement. OVERVIEW OF LITERATURE Little is written about lumbar fusion after optimally placed lumbar arthroplasty in patients with persistent lower back pains. METHODS Retrospective review of cases of lumbar artificial disc requiring subsequent fusion because of persistent back pains despite optimally placed artificial discs. Outcomes were evaluated using Oswestry Disability Index (ODI) and visual analogue scale (VAS). Clinical improvements indicated 25% improvement in ODI and VAS values. RESULTS Five patients met the study criteria. The mean baseline ODI for the five patients was 52. The mean baseline VAS scores for back and leg pains were 76 and 26, respectively. All the five patients had optimally placed prosthesis. The indication for surgery was the constant low back pains found in all the patients. Revision surgery involved disc explantation and fusion in two of the patients and posterolateral fusion without removing the prosthesis in three. None of the patients achieved adequate pain control after the revision surgery despite the solid bony fusion documented by postoperative computed tomography. The mean ODI value after the fusion was 55. The mean values for back and leg pains VAS were 72 and 30, respectively. CONCLUSIONS Lack of good pain relief after successful lumbar artifical disc replacements may indicate different etiology for the back pains. The spine-treating surgeons should have a high threshold level to perform salvage fusion at that level.