Initial Discectomy Associated with Aging Leading to Adjacent Disc Disease and Recurrence.

Abstract

Failure of surgery for lumbar disc herniation (LDH) can be commonly caused by recurrence. There are many debates regarding the risk factors of recurrent LDH (rLDH) and it is very difficult to define them because many clinical and complicated biomechanical parameters are involved. The purpose of study was to evaluate the long term result of re-discectomy for LDH at the same level and adjacent segments. Between 1999 and 2009, 1898 cases were operated and 142 (6.4%) patients underwent re-discectomy following initial operation. The study included 65 patients who were operated for single level discectomy, and their charts were analyzed retrospectively. There were 33 (50.8%) women and mean age was 45.5 years (24-73 years). rLDH was diagnosed at the initial level in 40 (61.5%) but adjacent and/or opposite level herniation (with or without the first level) was found in the remaining 25 cases (39.1%). Recurrence at the same level (SLG) and adjacent level groups (ALG) were similar according to the clinical outcomes in follow-up (mean 34.1 months). Admission period after initial operation was also parallel in SLG and ALG (54.7 and 53.1 months, respectively). However, the mean age of ALG (49.4 years) was significantly higher (p≤0.05) than SLG (42.8 years). After discectomy, collapsed discs are biomechanically more stable than those with preserved disc heights, and responses to axial compression on intervertebral disc pressure produced deformations of adjacent levels despite limitations. Altered biomechanical loading next to a fusion resulted in ongoing degeneration with aging at the affected entire lumbar spine.