Conservative versus surgical treatment in patients with lumbar disc herniation

BACKGROUND AND OBJECTIVES : Herniated disc is a common pathology, affecting about 5 to 10 cases per 1000 adults annually. A conservative or a surgical approach to treatment can be adopted. The present study’s objective was to evaluate each of these approaches. CONTENTS : An integrative literature review was carried out, ai-ming to understand which treatment provides greater benefits in the short, medium, and long term for patients with low back disc herniation. Of the 4941 articles found, 4852 were excluded by title, 75 by abstract and 14 were selected for the study. Of these 14 studies, 10 considered the conservative approach more beneficial to patients, while 4 considered the surgical conduct more beneficial. CONCLUSION : Surgical treatment is a good option for those cases in which patients have debilitating pain and need rapid pain relief. However, in the long run, there is no superiority of surgery over conservative treatment.


INTRODUCTION
Low back pain, or lumbago, and low back pain radiating to the lower limbs, or lumbosciatalgia, are common complaints in medical care. About 85% of cases involve low back disc herniation 1 , with an incidence of 5 to 20 cases in every 1000 adults 2 , being more common in people in the third to fifth decade of life, with a proportion twice as high in the male gender 2 . The intervertebral disc is composed of the fibrous ring and the nucleus pulposus 3 . The fibrous ring rupture is more frequent in the posterior part, where the collagen bundles are less dense, resulting in the expulsion of the nucleus pulposus 3 . Clinically there is increased pain when sitting, coughing or sneezing, and relief on standing or walking. Radiation of pain to the lower extremity and neurological symptoms such as numbness, motor weakness, and urinary or fecal incontinence are signs of advanced disease with disc prolapse, nerve root compression, or spinal stenosis 4 . The presence of disc protrusion doesn't necessarily mean that the patient will be symptomatic; in many cases it may be just an incidental finding on imaging exams 2 . There may be spontaneous regression of the herniated material and consequent improvement of symptoms, so that in more than 85% of patients the symptoms caused by acute herniated disc will resolve in 8 to 12 weeks, with no specific treatment 2 . Considering the possibility of conservative or surgical management, there are doubts as to which is the best for these patients in the short, medium and long term. The objective of this studye was to compare these two approaches to the available evidence in the literature.

CONTENTS
In order to perform the integrative review, first the problem was identified, then a literature search was performed, with delimitation of descriptors, databases and inclusion and exclusion criteria. Following that, the data obtained was evaluated and analyzed and the final text was composed.
The studies search occurred in September and October 2020, using the keywords: Conservative Treatment, Surgical procedures, Nucleus Pulposus, and intervertebral disc displacement. Free terms do not present in DeCS were also used. Studies in Portuguese, English, and Spanish published in the last five years that compared surgical and conservative treatment for lumbar disc herniation were included. Articles that included patients with radicular symptoms of diseases other than lumbar disc herniation, that included children or adolescents, and articles about cervical or thoracic disc herniation were excluded. A total of 4941 articles were found in the Scielo, Pubmed, Cochrane, CAPES, LILACS, and Revista Science platforms. Of those, 4852 were excluded by title, 76 by abstract, and only 14 were selected for meeting the inclusion criteria. Two authors acting independently examined the titles and abstracts of the articles obtained through the electronic search. The third author did a full reading of the final text. The data were not pooled due to the heterogeneity of the methodology used in each article. Figure 1 presents the summary of the article selection process. Table 1 shows the authors, surgical treatment, conservative treatment, and the main conclusions of each study. A cohort study 5 that retrospectively analyzed 277.941 symptomatic patients diagnosed with low back disc herniation found that 97% of them obtained success with conservative treatment and only 3% underwent surgery. According to the study, independent predictors of conservative treatment failure were male gender and previous opioid use. The study concluded that the best option for initial treatment is conservative treatment, since a high percentage of patients recover or experience gradual or substantial improvement within 4-6 weeks of treatment 1,7,8 . When comparing short-, medium-, and long-term outcomes, a systematic review published in 2019 found that surgery provides significantly greater short-and medium-term pain reduction, but this difference did not persist on the long term 9 . A cohort study with 370 patients showed that surgical treatment decreased lower back pain by 6 weeks more than conservative treatment; however, after 3 months, no relevant clinical difference was observed between the groups 10 . Another systematic review, with a sample of 2271 patients, came to the same conclusion, because within 1 to 3 months and 3 to 6 months, pain assessed by the visual analog scale (VAS) showed better results in patients who underwent surgery, but in the long term the results were similar 11 . Another study that assessed pain using the VAS, including 128 patients, 64 in the surgical group and 64 in the non-surgical group, concluded that at the end of the 6 months follow-up the patients who underwent surgery had a lower VAS score, which decreased from 7.7 at the beginning to 2.8 at the end of the study, compared to patients who received clinical treatment, whose pain decreased from 8 to 5.5 12 . A meta-analysis 13 that evaluated surgery with simple discectomy and discectomy with bone-anchored device versus continued conservative treatment, presented evidence that surgery is more effective for symptom relief than persisting with continued conservative treatment in cases where the patient is refractory to initial conservative treatment 13 . The evaluation of the success or failure of disc protrusion treatment by the quantitative sensory test (QST), which uses different stimuli to evaluate the perception of temperature and pain, found no differences in all parameters evaluated at the 3 to6 months follow-ups in patients treated conservatively with steroid injections or with surgical treatment 14 .

RESULTS
One of the studies compared total disc replacement surgery in 69 patients. In 57 patients who were treated conservatively there was no difference between surgery and conservative treatment at the 8-year follow-up, supporting the theory that the possible development of adjacent intervertebral disc degeneration is part of the natural course of disc degeneration, regardless of the treatment that was instituted 15 . Surgery provided better results by decompressing the affected nerve root when the outcome analyzed was the improvement of neuropathic pain. A study 16 that evaluated neuropathic pain using the Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) score found that the mean preoperative S-LANSS decreased from 11.4 to 7.5 one month after surgery, but a similar reduction was not observed in the group submitted to conservative treatment.  Intertransverse t r a n s m u s c u l a r microsurgery 83 patients were monitored, 37 of whom underwent surgery and 46 underwent conservative treatment. If surgical treatment for foraminal / extraforaminal low back disc herniation is delayed, the risk of persistent neuropathic pain (NP) may increase. NP can be prevented by sufficient decompression of the dorsal root ganglion.
Arts et al. 12 Systematic review and m e t a -analysis Non-surgical multimodal treatments, physical therapy, spinal manipulation, and epidural steroid injections.
Low back discectomy with bone anchored annular closure and low back discectomy Surgical treatment (low back discectomy and low back discectomy with bone anchored annular closure) is more effective than continuous conservative treatment for low back disc herniation. Low back discectomy with bone anchored annular closure > low back discectomy > conservative treatment. Surgical treatment was more effective in reducing leg pain, back pain and disability (herniated disc symptoms).

Bailey et al. 11
Prospective cohort Patient education, activities and exercises, use of oral analgesics and active physical therapy, as well as epidural injection of glucocorticoids.
Microdiscectomy Out of a total of 128 patients, 64 underwent conservative treatment and 64 surgical treatments. At the beginning of the study, the leg pain intensity score was 7.7 in the surgery group and 8 in the non-surgery group. At 6 months, the score for pain intensity was 2.8 in the surgery group and 5.2 in the non-surgery group Delgado-López et al. 1 Literature review The recommended initial treatment is generally conservative since a high percentage of patients recover or experience gradual and substantial pain improvement within 4-6 weeks. Both people who undergo surgery and those who are not submitted to it experience similar levels of pain after one year.
Chen et al. 10 Systematic review with s y s t e m atic reviews and meta--a n a l y s e s of randomized clinical trials Physical therapy, pharmacological therapy, and rest Clinical data suggest that surgery is more effective in improving physical function and quality of life than non-operative treatment. For patients with low back disc herniation, there is evidence that surgical treatment is more effective than conservative treatments in reducing short-and medium-term pain, short-term quality of life, and mediumand long-term disability.

DISCUSSION
Low back pain caused by herniated disc impacts several areas of an individual's life, especially between the 3 rd and 5 th decade of life 2 , when they are in an active working phase. There are Systematic review Physical therapy, pharmacological treatment, spinal manipulation, chiropractic treatment or a combination of these.
Surgery reduced leg pain by 6-20 points on a zero to 100 point pain scale at up to 26 weeks of follow-up. Differences between groups did not persist at 1 year or later. Minimal differences were observed at 2 years. Compared with nonsurgical interventions, surgery probably reduces pain and improves function in the short to medium term, but the difference does not persist in the medium to long term.
Garcia-Saiz et al. 13 Prospective cohort Epidural injection Simple discectomy 74 patients participated in the study: 50 underwent conservative treatment and 24 surgical treatments. After one month of follow-up, the patients submitted to surgery had better results on the QST than the patients submitted to steroid injection, this difference disappeared after 6 months of follow-up, when no statistically significant differences were found in any parameter measured by the QST.

Abou-Elroos et al. 20
Randomized controlled trial Physical therapy and rehabilitation (modification of activities); soft tissue massage; electrotherapy; static exercises for abdominal muscles, back muscles, and hip extensors; stretching exercises for the hamstrings, as well as range of motion (ROM) exercises; and pharmacological treatment with muscle relaxants, analgesics, anti-inflammatory drugs, pregabalin, and vitamin B complex.

Surgical discectomy
An extended physical therapy and rehabilitation program is beneficial and successful in patients with a recent diagnosis of low back disc herniation. This program can better improve functional capacity and facilitate the return to work compared to early surgical intervention. Other studies have reported that patients with low back disc prolapse who were treated surgically had better physical function and ability to work than those who were treated conservatively after 3 months; however, this difference was decreasing at the 2 years follow-up.

Petersen, Juhl and Fournier 17
Prospective cohort Multidisciplinary team with rheumatologists, physical therapists, chiropractors, and a social worker. Treatment included a thorough examination, biopsychosocial approach on patient concerns, education on activities of daily living, individually adapted exercises, and manual therapy based on physical examination findings.

Not specified.
Approximately 30% of patients with low back disc herniation or low back spinal stenosis were unsuccessful at 2-year follow-up when they underwent surgery after unsuccessful conservative treatment. Surgical treatment was associated with better outcomes than cases in which surgery was not an option. Regarding patients with low back disc herniation, factors associated with failure to achieve a disability outcome were male gender, low schooling level, high pain intensity, and generalized pain location. NSAIDs = nonsteroidal anti-inflammatory drugs. The studies 5,[6][7][8][9]11,13,14,17,20 report that conservative management is most beneficial to patients, while studies 10,11,12,15 report that surgical management is most beneficial to patients.
reports of prodromal history of mild to moderate axial pain for months, followed by an acute episode of pain radiating to lower limbs, distinguishing lumbosciatalgia 17 . Knowing the treatment options and the right moment to indicate a certain therapy is essential to improve quality of life of these patients and to enable them to return to their work activities as soon as possible. The evaluation of the success of therapy for lumbar disc herniation is heterogeneous because some articles 10,11,13 used the pain scale, others 9,10,11 applied quality of life questionnaires, such as the Short-Form Health Survey (SF-36), and disability level indexes, such as the Oswestry Disability Index, making it difficult to compare the results of the selected studies. In any case, it was clear that conservative treatment is the first option due to the benign nature of the disease and the high percentage of spontaneous regression of disc herniations 1,7,8 . On the other hand, there are cases in which surgical intervention is the absolute indication, such as cauda equina syndrome or significant paresis, which should be immediately operated 8 .
The ideal moment to indicate surgery in non-urgent cases is still uncertain, but conservative treatment for at least 6 weeks is recommended 7 . There is also the possibility of assessing the predictors of failure in prolonged conservative treatment, thus indicating surgery earlier. A cohort study 18 showed that male gender, low education, intense and generalized pain are predictors of conservative treatment failure. When comparing surgical and conservative treatment using pain scales, it was evidenced that surgery presents better results in the short and medium term; however, in the long term, patients had the same results, regardless of the type of treatment used [9][10][11] . This research is in agreement with classic studies that are emphatic in stating that after 1, 4 or 10 years of follow-up the comparative results between conservative and surgical treatment of herniated disc sciatalgia are statistically similar 19 .
Although MRI is an excellent method for diagnosing herniated disc, there is no indication for it to be used as a parameter of treatment failure or success, because most patients report symptom improvement long before any radiological improvement is seen 20 . The prolonged physical therapy and rehabilitation program is more beneficial and successful for patients with a recent diagnosis of low back disc herniation than early surgical intervention, because it improves the functional capacity and facilitates return to work 20 .

CONCLUSION
Conservative treatment is the initial treatment recommended for all cases of disc herniation, because it provides an earlier return to work activities. Surgical treatment is a good option for those cases that present debilitating pain and need quick relief; nevertheless, in the long term, for a period of one year or more, surgery is not superior to conservative treatment. As with all treatment, the patient's expectations and wishes must be taken into account when choosing different approaches.