What level of pain are patients happy to live with after surgery for lumbar degenerative disorders?
This study by Fekete et al, which has been approved for publication in The Spine Journal, provided an alternative approach to evaluating clinical outcomes in patients with degenerative lumbar disorders.
The study population was derived from a spine surgery outcomes database and EUROSPINE Spine Tango Registry. Over 6900 patients in the database met the inclusion criteria of which 6467 completed the baseline questionnaire. The Core Outcomes Measure Index (COMI) questionnaire was used by the investigators to evaluate back and leg pain, level of function, symptom-specific well-being (5 point scale), quality of life, and level of disability. Utilizing the question of “if you had to spend the rest of your life with symptoms you now have, how would you feel about it?” the authors used the top two potential responses (very satisfied or satisfied) to serve as proxy for an acceptable state of recovery.
Using this criteria, the cut-off score for indicating a satisfactory symptom state post-recovery was found to be less than or equal to 2 (on a 0 to 10 scale) for those with a lumbar disc herniation, and less than or equal to 3 for those treated for spinal stenosis, spondylolisthesis, deformity, or degenerative disc disease. This outcome was defined at 12 months postoperatively. It is unclear how the recorded diagnosis was determined and how patients were classified if they had more than one diagnosis (ie disc herniation and spondylolisthesis)?
In this study, 47% of patients reported an acceptable symptom state following lumbar spine surgery using the aforementioned criteria. The authors do make the valid point that those with pathology such as a herniated disc may be less accepting of any residual pain and expect complete relief moreso than those with other degenerative conditions of longer duration. There are varying explanations to account for this.
So how do we define success for those who undergo lumbar spinal surgery? As pointed out by Fekete, “the success of treatment should be measured in relation to its goals.” To patients, pain relief is one of the most important factors, if not the primary factor in determining outcome. Defining the level of pain that is considered acceptable, is very challenging, but is important if we wish really define surgical success.
As this was a cross-sectional study, there are inherent limitations present. Pain perception is highly subjective. There are many factors including psychosocial and other medical comorbities which can influence pain scores. The potential for secondary gain was not evaluated in this study, but certainly would affect point estimates of success in certain populations. While the results of this interesting study present a different approach to determining success, generalizability of the results are significantly limited due to study design and the potential for differences in cultural factors such as pain perception (Swiss population studied).