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.

Unilateral Paramedian Transpedicular Approach for Repair of Anterior Transdural Spinal Cord Herniation: Report of a Case and Literature Review

Idiopathic spinal cord herniation is a rare but potentially treatable cause of thoracic myelopathy. The rarity and variable clinical presentation often results in missed diagnosis and delay in treatment. Posterior midline approach with laminectomy has been the most common approach performed for spinal cord herniation in cases described in the literature. A posterior approach is limited by the danger of retracting the spinal cord and difficulty visualizing the dural defect. Considering the anterior location of the dural defect, a posterolateral allows for a more ventral view without spinal cord manipulation. We report a rare case of idiopathic spinal cord herniation which was managed by unilateral paramedian transpedicular approach with an excellent clinical outcome.