lnterbody Fusion for Disc Disease Following Discectomy

Introduction: Axial pain often follows lumbar discectomy. Workup frequently identifies no neural compression or instability while demonstrating findings similar to de novo degenerative disc disease (DDD). lnterbody fusion for axial pain following discectomy has not been studied. We aim to define the use of interbody fusion in this patient population.

Methods: This retrospective study focuses on seventeen patients with a prior single–level discectomy without evidence of instability. Patients underwent interbody fusion at the level of prior discectomy and were assessed in regards to axial pain, narcotic use and functional status a minimum of one year following surgery (mean=21 months).

Results: The study group consists of eight females and nine males with a mean age of 46 years. Eight patients had workman's compensation claims (WCC). Fourteen patients underwent an anterior interbody fusion while three underwent posterior interbody fusion (PLIF). Radiographic fusion was obtained in 94%. A good clinical result was defined by lack of narcotic use, return to work and greater than 90% relief of axial pain. Forty–seven percent of patients achieved a good clinical outcome. Fifty–two percent (9/17) returned to gainful employment. Nine of 17 patients reported greater than 90% relief of back pain. Good and bad outcome groups did not differ in age (46 vs. 46 yrs) or length of follow–up (23 vs. 18 months). Seventy–five percent of patients without WCC had good outcomes while less than a quarter of cases related to WCC had a good outcome (P less than 0.05). Of the nine patients with a poor result, only one had an unequivocal discogram with six reporting pain at multiple levels. Neither of the two patients who underwent two level fusions nor the three patients with PLIFs had a good outcome.

Conclusion: Although limited by retrospective design and study size, the results suggest that a select group of patients with axial pain following discectomy may benefit from interbody fusion. Absence of WCC, an unequivocal discogram and limitation of fusion to a single level were associated with a good outcome.