Initial Discectomy Associated with Aging Lead to Adjacent Disc Disease and Recurrence

AbstractAim:Failure of surgery for lumbar disc herniation (LDH) can be commonly caused by recurrence. There are many debates regarding the risk factors of 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.

Material and Methods:Between 1999 and 2009, overall 1898 cases were operated on 142(6,4%) patients underwent re-discectomy following initially operation. The study included 64 patients who were operated on single level discectomy, and their charts analyzed retrospectively.

Results:There were 32(50%) women and mean age was 45,5 years (24–73). rLDH was diagnosed at initial level in 39(60,9%), but adjacent and/or opposite level herniation (with or without the first level) were founded in remaining 25 cases (39,1%). Recurrence at same level (SLG) and adjacent level groups (ALG) were similar according to the clinical outcomes in follow-up meanly (34,1 months). Admission period after initial operation was also parallel SLG and ALG (54,7 and 53,1 months, respectively) however mean age of ALG (49,4) was significantly higher (p≤0,05) than SLG (42,8).

ConclusIon:After disectomy, collapsed discs are biomechanically more stable than those with preserved disc height, and responses to axial compression on intervertebral disc pressure caused to deformations of adjacent levels despite of its appear to be limited. Altered biomechanical loading next to a fusion resulted in ongoing degeneration with aging at the affecting entire lumbar spine.

Keywords:lumbar disc herniation, reccurence, adjacent segment, aging

IntroductionLumbar discectomy is the most common surgical procedure performed by spine surgeons for patients compliant of back and leg pain. Numerous new techniques have been used to improve the efficacy of the surgical excision of herniated intervertebral discs; however, these procedures still include some difficulties, especially the persistence and recurrence of symptoms. Failure of surgical treatment for LDH can be caused by the true recurrence of disc herniation, new disc herniation at a different disc level, epidural fibrosis, arachnoiditis, foraminal stenosis, and segmental instability (8, 21-23, 29, 30, 32). The overall rate of unsatisfactory discectomy results ranges from 5% to 20% and recurrent disc herniation remains the major source of disability that is reported in 5% to 11% of patients (8, 21, 29, 32). The rate of necessary repeat interventions following primary discectomy ranges from 4% and 18% and depends on the duration of the follow-up (7, 12, 21, 28).There are many debates regarding the risk factors of recurrent LDH (rLDH) and it is quite difficult to define them, because many clinical and complicated biomechanical parameters are involved. Many studies have investigated various risk factors for rLDH, such as disc degeneration, trauma, age, smoking, gender, and obesity (6, 28, 29). Kim et al reported old age, high BMI, protrusion type disc, and positive Modic change as risk factors (16). Carragee et al found that the degree of annular competence after a discectomy and the type of herniation were correlated with the recurrent rates after discectomies (5). However, these factors have not reflected the biomechanical stress on the affected disc level and joint, which might be related to rLDH. The purposes of this study were to evaluate the long-term result of repeat surgery for recurrent disc herniation, and to compare the frequency of recurrence where levels as contra-laterally, bilaterally, and adjacent segments.