Background: Despite the evident progress in treating vertebral column degenerative diseases, the rate
of a so-called “failed back surgery syndrome” associated with pain and disability remains relatively high.
However, this term has an imprecise definition and includes several different morbid conditions following
spinal surgery, not all of which directly illustrate the efficacy of the applied technology; furthermore,
some of them could even be irrelevant.
Objective: To evaluate and systematize the reasons for persistent pain syndromes following surgical
nerve root decompression.
Study Design: Prospective, nonrandomized, cohort study of 138 consecutive patients with radicular
pain syndromes, associated with nerve root compression caused by lumbar disc herniation, and resistant
to conservative therapy for at least one month. The minimal period of follow-up was 18 months.
Setting: Hospital outpatient department, Russian Federation
Methods: Pre-operatively, patients were examined clinically, applying the visual analog scale (VAS),
Oswestry Disability Index (ODI), magnetic resonance imaging (MRI), discography and computed
tomography (CT). According to the disc herniation morphology and applied type of surgery, all participants
were divided into the following groups: for those with disc extrusion or sequester, microdiscectomy was
applied (n = 65); for those with disc protrusion, nucleoplasty was applied (n = 46); for those with disc
extrusion, nucleoplasty was applied (n = 27). After surgery, participants were examined clinically and
the VAS and ODI were applied. All those with permanent or temporary pain syndromes were examined
applying MRI imaging, functional roentgenograms, and, to validate the cause of pain syndromes,
different types of blocks were applied (facet joint blocks, paravertebral muscular blocks, transforaminal
and caudal epidural blocks).
Results: Group 1 showed a considerable rate of pain syndromes related to tissue damage during the
intervention; the rates of radicular pain caused by epidural scar and myofascial pain were 12.3% and
26.1% respectively. Facet joint pain was found in 23.1% of the cases. Group 2 showed a significant rate
of facet joint pain (16.9%) despite the minimally invasive intervention. The specificity of Group 3 was the
very high rate of unresolved or recurred nerve root compression (63.0%); in other words, in the majority of
cases, the aim of the intervention was not achieved. The results of the applied intervention were considered
clinically significant if 50% pain relief on the VAS and a 40% decrease in the ODI were achieved.
Limitations: This study is limited because of the loss of participants to follow-up and because it is
nonrandomized; also it could be criticized because the dynamics of numeric scores were not provided.
Conclusion: The results of our study show that an analysis of the reasons for failures and partial effects
of applied interventions for nerve root decompression may help to understand better the efficacy of the
interventions and could be helpful in improving surgical strategies, otherwise the validity of the conclusion
could be limited because not all sources of residual pain illustrate the applied technology efficacy. In the
majority of cases, the cause of the residual or recurrent pain can be identified, and this may open new
possibilities to improve the condition of patients presenting with failed back surgery syndrome.
Key words: microdiscectomy, nucleoplasty, epidural scar, facet joint pain, recurrent herniation,
myofascial pain
An Analysis of Reasons for Failed Back
Surgery Syndrome and Partial Results after
Different Types of Surgical Lumbar Nerve Root
Decompression
