Postoperative Low Back Pain Research Articles

Association of Serum Serotonin and Pain in Patients with Chronic Low Back Pain before and after Spinal Surgery.

Introduction In this study we are aiming to evaluate the changes of serum serotonin and its association with pain in patients suffering from chronic low back pain before and after lumbar discectomy surgery. Patients and Methods A prospective study was performed on the patients referring to the outpatient clinic in Besat hospital, Hamadan University of Medical Sciences, Hamadan, Iran, during 2016. A 2 mL fasting blood sample was collected from each patient at preoperative day 1 and postoperative day 14 and they were measured for level of serum serotonin. Besides, all patients were asked for severity of their low back pain in preoperative day 1 and postoperative day 14 and scored their pain from zero to ten using a Numerical Rating Scale. Results Forty patients with the mean age of 47 ± 13 yrs/old (range 25–77) including 15 (37.5%) males were enrolled into the study. The overall mean score of preoperative pain was significantly decreased from 7.4 ± 2.18 (range 4–10) to the postoperative pain score 3.87 ± 2.92 (range 0–10) (P < .001). The overall levels of pre- and postoperative serum serotonin were 3.37 ± 1.27 (range 1.1–6.4) and 3.58 ± 1.32 (range .94–7.1) ng/mL, respectively, with no significant difference (P = .09). The levels of pre- and postoperative serum serotonin were significantly higher in males and patients older than 50 yrs/old compared to the females and patients younger than 50 yrs/old, respectively (P = .03 and .005, respectively). A significant inverse correlation between the postoperative levels of pain and serum serotonin was observed (r = -.36 and P = .02). Conclusion A negative medium strength linear relationship may exist between the postoperative serum serotonin and low back pain.

Lumbar disc herniation treated by microendoscopic discectomy : Prognostic predictors of long-term postoperative outcome.

Microendoscopic discectomy (MED) is becoming an established and effective minimally invasive surgical method for the treatment of lumbar disc herniation (LDH); however, the absence of prognostic factors for long-term outcomes after MED results in alack of specific criteria for appropriate patient selection. Therefore, we evaluated the long-term outcomes and associated predictors in patients who underwent MED for LDH. Baseline and follow-up data for 664LDH patients who suffered from sciatica and underwent primary MED were reviewed retrospectively. Variables at baseline that were analyzed as potential prognostic factors included sociodemographic characteristics, clinical findings, and imaging features. Follow-up data including improvements in the Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI), postoperative low back pain (LBP), reoperation, and excellent/good results according to the modified MacNab criteria were set as outcome variables for univariate and further multivariate logistic regression analyses. The mean follow-up period was 63.8 ± 20.0months (range 24-96months). On average, sufficient improvements in both the VAS score (72.8%) and ODI (63.4%) were observed. In addition, alow postoperative LBP rate (23.9%), low reoperation rate (7.1%), and high rate of excellent/good clinical outcomes (89.9%) were achieved. Amultivariate analysis indicated that older age, shorter disease duration, higher preoperative VAS score, lower preoperative ODI, shorter surgical time, lower severity of disc and adjacent disc degeneration, and lower severity of lumbar multifidus atrophy contributed to superior clinical outcomes. Excellent long-term outcomes after primary MED were achieved and specific sociodemographic, clinical, and imaging variables were identified as prognostic factors that can be used to guide patient selection and clinical decision making.

Comparison Between Percutaneous Endoscopic Lumbar Discectomy and Minimally Invasive Transforaminal Lumbar Interbody Fusion for Lumbar Disc Herniation with Biradicular Symptoms

To compare the clinical outcomes of patients with lumbar disc herniation with bi-radicular symptoms undergoing percutaneous endoscopic lumbar discectomy (PELD) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). From January 2008 to January 2016, 89 consecutive patients with lumbar disc herniation with biradicular symptoms were treated with PELD or MIS-TLIF. The data were collected prospectively for analysis including clinical and radiographic results after revision surgery and complications. During the follow-up period, the postoperative data between the 2 treatment groups showed no significant difference in the mean total postoperative visual analog score for leg pain and the Japanese Orthopedic Association and Oswestry disability index scores. In the MIS-TLIF group, the recovery rate and satisfaction rate were higher than those in the PELD group, and the difference was statistically significant. The only postoperative factor that was significantly different was postoperative back pain, which was lower in the MIS-TILF group. The other significant differences between the 2 treatment groups were associated with the complications such as intervertebral infection and adjacent segment disease. Both PELD and MIS-TLIF, as treatments for lumbar disc herniation with biradicular symptoms, showed favorable clinical outcomes. Compared with MIS-TLIF, PELD had the following advantages: 1) it is performed under local anesthesia and 2) there is rare possibility of "fusion disease," such as ASD. However, the PELD is also revealed several problems, including a relatively lower success rate and satisfaction, a relative higher rate of postoperative long-term chronic low back pain and the possibility of recurrence, despite the low incidence.

Influence of Skeletal Muscle Mass and Spinal Alignment on Surgical Outcomes for Lumbar Spinal Stenosis.

Study Design Retrospective observational study.Purpose We considered the relationship between spinal alignment and skeletal muscle mass on clinical outcomes following a surgery for lumbar spinal stenosis (LSS).Overview of Literature There are no reports of preoperative factors predicting residual low back pain following surgery for LSS.Methods Our target population included 34 women (mean age, 74.4 years) who underwent surgery for LSS. Prior to and 6 months after the surgery, systemic bone mineral density and lean soft tissue mass were measured using dual-energy X-ray absorptiometry. Skeletal muscle mass index (SMI) was calculated as the sum of the arm and leg lean mass in kilograms divided by height in meters squared. The spinal alignment was also measured. Clinical outcomes were evaluated using the Japanese Orthopedic Association scoring system, leg and low back pain Visual Analog Scale, and Roland–Morris Disability Questionnaire (RDQ). Additionally, we examined the bone mineral density, skeletal muscle mass, and spinal alignment before and after the surgery. We used the Spearman correlation coefficient to examine the associations among clinical outcomes, preoperative muscle mass, and spinal alignment.Results Sarcopenia (SMI <5.46) was observed in nine subjects (26.5%). Compared with normal subjects (SMI >6.12), RDQ was significantly higher in subjects with sarcopenia (p =0.04). RDQ was significantly negatively correlated with SMI (r =−0.42, p <0.05). There was a significant positive correlation between postoperative RDQ and pelvic tilt (PT; r =0.41, p <0.05). SMI and PT were significantly negatively correlated (r =−0.39, r <0.05).Conclusions Good postoperative outcomes were negatively correlated with low preoperative appendicular muscle mass, suggesting that postoperative outcomes were inferior in cases of decreased appendicular muscle mass (sarcopenia). Posterior PT due to decreased limb muscle mass may contribute to postoperative back pain, showing that preoperatively reduced limb muscle mass and posterior PT are predictive factors in the persistence of postoperative low back pain.

Preoperative practice of surgical position reduces postoperative pain and discomfort in patients receiving kidney surgeries: a nonrandomized pilot study.

ObjectiveProlonged maintenance of surgical position often results in postoperative pain and discomfort in patients. The present study aimed to investigate the effect of preoperative practice of surgical position on postoperative pain and general comfort in patients receiving kidney surgeries.MethodsFor this nonrandomized pilot study, 74 patients receiving kidney surgeries were selected using the probability sampling method. Patients from ward 1 were assigned to the practice group (n=35), and those from ward 2 were assigned to the control group (n=39). The practice group were instructed to practice the surgical position for 3 days prior to the surgery. Postoperative pain and comfort were surveyed using two questionnaires for 3 days, respectively. The postoperative pain scores were compared using the Student’s t-test.ResultsThe two groups did not differ significantly in wound pain on postoperative days 1–3 (P > 0.05). However, the practice group showed significantly reduced low back pain and contralateral shoulder pain than the control group for 3 postoperative days (P < 0.05). The physical domain score was significantly higher in the practice group than in the control group (P < 0.01).ConclusionPreoperative practice of surgical position can effectively reduce postoperative low back pain and contralateral shoulder pain in patients receiving kidney surgeries and improve the physical comfort.

Comparison of posterolateral fusion and posterior lumbar interbody fusion for treatment of degenerative spondylolisthesis: Analysis of spino-pelvic sagittal balance and postoperative chronic low back pain

ObjectiveThis study aims to compare the spino-pelvic sagittal balance and clinical outcomes of patients treated with posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative spondylolisthesis. Patients and MethodsA total of 72 patients (28 patients treated with PLF and 44 patients treated with PLIF) were studied. The spino-pelvic sagittal balance, Numerical Rating Scale (NRS), and Oswestry Disability Index (ODI) of the PLF and PLIF groups were compared. The incidence of postoperative chronic low back pain (improvement of NRS less than 50%) in the two groups was also recorded. ResultsSignificant restoration of spino-pelvic sagittal balance was observed in the PLIF group after surgery. Both groups achieved significant improvements in NRS and ODI postoperatively. Significant differences in postoperative lumbar lordosis and pelvic tilt were found between the PLF and PLIF groups. Significant difference in the incidence of postoperative chronic low back pain was also detected between the two groups. ConclusionPLF and PLIF can improve the clinical outcomes of patients with degenerative spondylolisthesis. PLIF can achieve better restoration of spino-pelvic sagittal balance parameters and less incidence of postoperative chronic low back pain than PLF.

Polyetheretherketone Rods in Lumbar Spine Degenerative Disease: Mid-term Results in a Patient Series Involving Radiological and Clinical Assessment.

To evaluate the satisfaction of patients operated due to degenerative lumbar spinal diseases with dynamic stabilization placing polyetheretherketone (PEEK) rods and to share their radiological and clinical results (mid-term) with visual analogue scale (VAS) and Oswestry disability index (ODI) scores. The preoperative and postoperative low back pain, leg pain VAS and ODI scores of 172 patients who were operated for degenerative spinal diseases, were evaluated. Preoperative and postoperative lumbar lordosis were compared. The patients included to the study were evaluated postoperatively around the 2nd year with lumbar MRI by means of adjacent segment disease (ASD) and additional problems. A statistically but not radiologically-by means of sagittal profile reconstruction-significant increase in lumbar lordosis angle was achieved. Significant improvement was observed in the comparison of preoperative and postoperative period in the analysis of patients’ preoperative low back pain (p < 0.0001), and decompression-related leg pain VAS scores (p < 0.0001). Significant improvement was also observed in the ODI scores of the patients (p < 0.0001). Among 172 patients with dynamic stabilization, there were 10 patients who underwent reoperation (5.8%). Although it is statistically significant, it can be seen that the lumbar lordosis can not be corrected at significant degrees radiographically in the operations performed with the PEEK rod. Dynamic stabilization with PEEK rod is insufficient for sagittal correction, but the mid-term results reached satisfactory reoperation rates clinically outcomes. Rate of ASD is quite low in stabilization with PEEK rod.

Short-term effectiveness of accurate decompression via foraminoplasty in treatment of lumbar lateral recess stenosis

To discuss the effectiveness and the safety of accurate decompression via foraminoplasty in treating lumbar lateral recess stenosis patients who accompanied by disk-flavum ligamentum space and bony lateral recess stenosis, and to analysis the short-term effectiveness of the surgical procedures. Forty-five lumbar lateral recess stenosis patients accompanied by disk-flavum ligamentum space and bony lateral recess stenosis were treated by accurate decompression via foraminoplasty between January 2013 and January 2016. There were 29 males and 16 females with a median age of 58 years (range, 42-82 years). The disease duration was 3-96 months (mean, 24.4 months). The lesion segment included L 4, 5 in 36 cases and L 5, S 1 in 9 cases. The visual analogue scale (VAS) score of low back pain and leg pain at preoperation and last follow-up were recorded, and the modified Macnab criteria was used to evaluate the effectiveness at last follow-up. Postoperative CT and MRI were reviewed to evaluate the stability and decompression of the lumbar spine. All operations were successfully completed. All the 45 patients were followed up 3-18 months (median, 11 months). Dural tear occurred in 2 cases during operation, bone graft removed into the spinal canal in 1 case, postoperative low back pain occurred in 5 cases, and there was no nerve root injury, hematoma formation, or other complications. The leg pain VAS score at last follow-up (0.6±1.2) was significantly improved when compared with preoperative score (5.7±1.4) ( t=8.981, P=0.001); and the low back pain VAS scores showed no significant difference between preoperation and last follow-up (1.5±1.3 vs. 1.7±1.4; t=0.535, P=0.585). According to the modified Macnab criteria, the results were excellent in 20 cases, good in 22 cases, fair in 2 cases, and poor in 1 case at last follow-up, and the excellent and good rate was 93.3%. Accurate decompression via foraminoplasty is an effective, safe, and less invasive way for treating lumbar recess stenosis patients accompanied by disk-flavum ligamentum space and bony lateral recess stenosis.

Manipulative rehabilitation applied soon after lumbar disc surgery improves late post-operative functional disability: A preliminary 2-year follow-up study.

Studies have shown late post-operative physical disability and residual pain in patients following lumbar disc surgery despite growing evidence of its beneficial effects. Therefore, rehabilitation is required to minimise the late post-operative complications. To assess the feasibility of manipulative rehabilitation to improve late post-operative outcomes. Twenty-one patients aged 25-65 years undergoing lumbar microdiscectomy were randomly assigned to the rehabilitation group (n= 14) or active control group (n= 7) by simple randomisation. Eight rehabilitation sessions were initiated 2-3 weeks after surgery. Thirty-minute sessions were conducted twice weekly for four weeks. Post-operative physical disability and pain were assessed at baseline and at the two-year follow-up. Post-operative physical disability improved more in patients who had undergone rehabilitation than in those who had received control care (63% vs. -23%, P< 0.05). Post-operative residual low back and leg pain were alleviated in the treatment group (26% and 57%, respectively), but intensified in the control group (-5% and -8%, respectively). This study demonstrated the potential of manipulative rehabilitation and importance of post-operative management after lumbar disc surgery. Definitive trials with larger sample sizes are required to confirm the feasibility and potential therapeutic effectiveness of this approach.

Risk Factors of Postoperative Low Back Pain for Low-Grade Degenerative Spondylolisthesis: An At Least 2-Year Follow-Up Retrospective Study.

A retrospective study was conducted to clarify the risk factors of postoperative low back pain (LBP) for low-grade degenerative spondylolisthesis. A total of 239 patients who underwent posterior lumbar fusion between January 2011 and January 2015 were included in this analysis. We investigated patient characteristics, surgical characteristics, and radiographic characteristics. The mean visual analog scale (VAS) score of LBP decreased dramatically after the operation. The mean preoperative VAS score was greater in patients with severe lumbar multifidus (LM) intramuscular adipose tissue (IMAT). The postoperative VAS score was dramatically lower in patients with shorter symptom duration. Postoperative LBP disappeared more often in patients with shorter symptom duration. LBP VAS changing showed significant differences in different symptom duration groups and LM IMAT groups. LM IMAT and symptom duration were risk factors for postoperative LBP. Patients with severe LM IMAT reported more severe LBP before the operation. Postoperative LBP disappeared more often in patients with shorter symptom duration.

The Effectiveness of Neural Mobilization for Neuromusculoskeletal Conditions: A Systematic Review and Meta-analysis.

Study Design Systematic review with meta-analysis. Objectives To determine the efficacy of neural mobilization (NM) for musculoskeletal conditions with a neuropathic component. Background Neural mobilization, or neurodynamics, is a movement-based intervention aimed at restoring the homeostasis in and around the nervous system. The current level of evidence for NM is largely unknown. Methods A database search for randomized trials investigating the effect of NM on neuromusculoskeletal conditions was conducted, using standard methods for article identification, selection, and quality appraisal. Where possible, studies were pooled for meta-analysis, with pain, disability, and function as the primary outcomes. Results Forty studies were included in this review, of which 17 had a low risk of bias. Meta-analyses could only be performed on self-reported outcomes. For chronic low back pain, disability (Oswestry Disability Questionnaire [0-50]: mean difference, -9.26; 95% confidence interval [CI]: -14.50, -4.01; P<.001) and pain (intensity [0-10]: mean difference, -1.78; 95% CI: -2.55, -1.01; P<.001) improved following NM. For chronic neck-arm pain, pain improved (intensity: mean difference, -1.89; 95% CI: -3.14, -0.64; P<.001) following NM. For most of the clinical outcomes in individuals with carpal tunnel syndrome, NM was not effective (P>.11) but showed some positive neurophysiological effects (eg, reduced intraneural edema). Due to a scarcity of studies or conflicting results, the effect of NM remains uncertain for various conditions, such as postoperative low back pain, cubital tunnel syndrome, and lateral epicondylalgia. Conclusion This review reveals benefits of NM for back and neck pain, but the effect of NM on other conditions remains unclear. Due to the limited evidence and varying methodological quality, conclusions may change over time. Level of Evidence Therapy, level 1a. J Orthop Sports Phys Ther 2017;47(9):593-615. Epub 13 Jul 2017. doi:10.2519/jospt.2017.7117.

The Long-term Clinical Effect of Minimal-Invasive TLIF Technique in 1-Segment Lumbar Disease.

A prospective cohort double-center study. To assess the clinical effect of minimally invasive transforaminal lumbar interbody fusion (miTLIF) using the tunnel technique. A series of short-term studies have indicated that miTLIF could reduce blood loss and improve clinical results. However, long-term clinical study and magnetic resonance imaging research are still scare. From January 2008 to January 2009, 187 patients with 1-segment lumbar disease requiring intervertebral fusion were enrolled in this study. Patients were divided into 2 groups according to the operative methods. Postoperative low back pain (LBP), postoperative lumbar function, the fusion rate, lower extremity pain relief, variation of lumbar lordosis, and implant failure were assessed. At 48 months postoperation, the cross-sectional area of the paraspinal muscle was measured using magnetic resonance imaging. The mean duration of follow-up was 54.4±5.9 months. The intermuscular pressure generated by the tunnel in the miTLIF group was lower than that generated in the oTLIF group. Patients in the miTLIF group reported a lower degree of LBP at all timepoints. The ODI scores were similar to the VAS scores. No significant differences were found in fusion rate, lower extremity pain relief, lumbar lordosis, or implant failure rate. A significant difference was found between the 2 groups in postoperative cross-sectional area. This study confirmed the advantages of miTLIF in reducing postoperative LBP, improving postoperative quality of life and preventing paraspinal muscle atrophy compared with oTLIF, while achieving a similar therapeutic outcome. The lower intermuscular pressure generated by minimally invasive tunnel and subsequent moderate muscle atrophy were presumed to be possible reasons for its superiority.

Clinical and radiological outcomes after decompression and posterior fusion in patients with degenerative scoliosis

Objective: The prevalence of degenerative scoliosis (DS) increases with age and an overall increase is seen due to the aging population. This study aims to evaluate the clinical and radiological outcomes after decompression and posterior fusion in patients with DS.Methods: In this is prospective study, 43 patients with DS, aged 37 to 70 years, were eligible to undergo decompression and posterior fusion. Primary outcomes were low back pain (LBP) with or without radicular pain, which was evaluated preoperatively and at 12 and 24 months after surgery with the use of a visual analog scale (VAS), and the quality of life (QOL), which was assessed at the same time periods by the Oswestry Disability Index (ODI) questionnaire. The Cobb's method was used to measure the degree of scoliosis in each patient preoperatively and at 24 hours, 12 and 24 months after the surgery.Results: VAS scores improved significantly from a mean of 8.18 preoperatively to 4.48 at 12 months and 3.07 at 24 months postoperatively (P < .001). The mean radicular pain scores also decreased significantly (P < .001). At postoperative 12 months, the mean ODI score was significantly lower than the mean preoperative ODI score (47.81 ± 16.06 vs. 72.18 ± 12.28; P = .001). ODI score at 24 months postoperatively was significantly better than the preoperative ODI (15.53 ± 7.21 vs. 72.18 ± 12.28; P = .016). The mean Cobb angle changed significantly from 31.4° ± 4.88 preoperatively to 3.28° ± 2.10 at 24 months postoperatively (P < .001).Conclusions: Our findings suggest that decompression and posterior fusion in the patients with DS is an effective surgical method which is associated with satisfying clinical results in terms of improvement of postoperative LBP, radicular pain, and QOL, and correction of Cobb angle at 12 and 24 months after the surgery and restoration of sagittal alignment at 2 months postoperatively.

Diagnosing Discogenic Low Back Pain Associated with Degenerative Disc Disease Using a Medical Interview.

PurposesTo evaluate the usefulness of our original five questions in a medical interview for diagnosing discogenic low back pain (LBP), and to establish a support tool for diagnosing discogenic LBP.Materials and MethodsThe degenerative disc disease (DDD) group (n = 42) comprised patients diagnosed with discogenic LBP associated with DDD, on the basis of magnetic resonance imaging findings and response to analgesic discography (discoblock). The control group (n = 30) comprised patients with LBP due to a reason other than DDD. We selected patients from those who had been diagnosed with lumbar spinal stenosis and had undergone decompression surgery without fusion. Of them, those whose postoperative LBP was significantly decreased were included in the control group. We asked patients in both groups whether they experienced LBP after sitting too long, while standing after sitting too long, squirming in a chair after sitting too long, while washing one’s face, and in the standing position with flexion. We analyzed the usefulness of our five questions for diagnosing discogenic LBP, and performed receiver operating characteristic (ROC) curve analysis to develop a diagnostic support tool.ResultsThere were no significant differences in baseline characteristics, except age, between the groups. There were significant differences between the groups for all five questions. In the age-adjusted analyses, the odds ratios of LBP after sitting too long, while standing after sitting too long, squirming in a chair after sitting too long, while washing one’s face, and in standing position with flexion were 10.5, 8.5, 4.0, 10.8, and 11.8, respectively. The integer scores were 11, 9, 4, 11, and 12, respectively, and the sum of the points of the five scores ranged from 0 to 47. Results of the ROC analysis were as follows: cut-off value, 31 points; area under the curve, 0.92302; sensitivity, 100%; and specificity, 71.4%.ConclusionsAll five questions were useful for diagnosing discogenic LBP. We established the scoring system as a support tool for diagnosing discogenic LBP.

Percutaneous Endoscopic Lumbar Diskectomy and Minimally Invasive Transforaminal Lumbar Interbody Fusion for Recurrent Lumbar Disk Herniation

To compare the clinical outcomes of patients with recurrent lumbar disk disease undergoing percutaneous endoscopic lumbar diskectomy or minimally invasive transforaminal lumbar interbody fusion at a single clinic. From January 2008 to January 2014, 401 consecutive patients with first recurrence of lumbar disk herniation were treated with percutaneous endoscopic lumbar diskectomy (PELD) or minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). These data collected prospectively for analysis were clinical and radiographic results after revision surgery and complications. During the follow-up period, postoperative data between both groups showed no significant differences in the mean total postoperative visual analog scale score for leg pain, Japanese Orthopaedic Association score, and Oswestry Disability Index score. The recovery rate was 92.3% in the PELD and 97.4% in the MIS-TLIF group. Regarding satisfactory rate, the PELD group (91.3%) was lower than the MIS-TLIF group (95.2%). Six cases of dural tear were observed in the MIS-TLIF group. The second recurrence occurred in 12 patients in the PELD group. In the PELD group, 1 patient suffered from permanent neurologic deficit. One case of postoperative intervertebral infection was captured in the MIS-TLIF group. Both PELD and MIS-TLIF showed favorable clinical outcomes for recurrent disk herniation. Compared with MIS-TLIF, PELD has the following several advantages: 1) performed under local anesthesia; 2) performed with very few approach-related complications, such as dural tear; and 3) rare possibility of fusion disease, such as adjacent segment. However, PELD is also faced with several problems, such as 1) the relative higher rate of postoperative long-term chronic low back pain, and (2) the possibility of recurrence, despite the opportunity being low.

Risk Factors of Postoperative Low Back Pain for Lumbar Spine Disease

A retrospective study was conducted to clarify the risk factors of postoperative low back pain (LBP) for lumbar spine disease. A total of 401 patients who underwent lumbar operation between January 2011 and December 2011 were included in this analysis. We investigated patient characteristics and surgical approaches and also compared the radiographic characteristics. The mean visual analogue scale (VAS) score decreased dramatically after the operation. The mean preoperative VAS score was greater in patients underwent posterior lumbar interbody fusion (PLIF) with longer duration of symptoms, longer operation time, and severe lumbar multifidus (LM) intramuscular adipose tissue (IMAT). The preoperative VAS score was dramatically lower in patients with lumbar herniation. The postoperative VAS score was dramatically lower in patients who underwent PLIF with longer operation time and mild LM IMAT. Postoperative LBP disappeared more often in patients who underwent PLIF with longer operation times. The number of operative levels and type of lumbar spine disease also were associated with postoperative LBP. Type of surgery, operation time, number of operative level, and type of disease were risk factors for the postoperative LBP. Patients underwent PLIF with shorter symptom duration, longer operation time severe LM IMAT, and lumber spondylolisthesis reported more severe LBP before the operation. Patients underwent discectomy with shorter operation times.

Letter to the Editor: The effect of methylene blue on postoperative low-back pain.

Letter to the Editor: The effect of methylene blue on postoperative low-back pain.

Serum creatine phosphokinase levels as an indicator of muscle injury following lumbar disc surgery: Comparison of fully endoscopic discectomy and microdiscectomy

ObjectiveThe aim of this study is to make a comparison between fully endoscopic lumbar discectomy (FELD) and conventional microdiscectomy (MD) by using pre- and postoperative serum creatine phosphokinase (CPK) levels in correlation with postoperative low-back pain. MethodsFortyfive consecutive patients who underwent surgery for lumbar disc herniation were allocated into three groups with 15 patients on each: (1) FELD with interlaminar approach (IL), (2) FELD with transforaminal approach (TF), (3) Conventional MD. Serum CPK levels pre- and 1, 6, 12 and 24h postoperatively, patients’ body mass index (BMI), operation duration and hospital stays were recorded. The low-back pain pre- and postoperatively was assessed with the use of the 100mm visual analog scale (VAS) and the “Oswestry Disability Index” (ODI). ResultsThere were 16 female (35.5%) and 29 male (64.5%) patients with a mean age of 44.1 years. CPK levels at 6th, 12th and 24th hours postoperatively were found significantly lower in TF and IL groups compared to MD group (p<0.004). Mean operation duration was significantly shorter in MD group (p: 0.014). There was a significant decrease in both the VAS and ODI scores after the surgery in all patient groups (p<0.001). Postoperative VAS scores were found significantly higher in MD group (p: 0.04). ConclusionMinimal invasive nature of FELD procedures compared to the MD was substantiated by serum CPK levels in this study. To draw definitive conclusions regarding pain relief, larger patient samples should be evaluated, although postoperative VAS scores were found in favor of FELD.

Results after Lumbar Discectomy for Herniated Disc in Worker's Compensation Patients: more than 15 Years of Follow- up

Introduction Published literature has identified worker's compensation population to have worse results after lumbar discectomy for herniated disc compared with general population. However the advantage of complete follow-up due to its captive population is well know. This study aims to evaluate lumbar discectomy outcomes, prognostic factors and recurrence rate after more than15 years of follow-up. Material and Methods A retrospective review of 50 worker's compensation patients operated consecutively between 1997–1998 in Hospital del Trabajador for primary herniated lumbar disc was performed. Electronic medical records analysis was conducted until June 2015. Primary outcomes were surgical complications, sick leave, return to work, work compensation, chronic postoperative low back pain and reoperation for recurrent lumbar disc herniation. Statistical analysis looking for prognostic factors in lumbar discectomy evolution was realized. Results We found 44 men and 6 women with a mean age of 36.5 (22–66) years. One hundred percent follow-up was achieved with a mean time of 18 (17.5–18.5) years. Most patients were light workers (58%). Lumbar herniated discs were mostly located at L5-S1 ( n = 35) followed by L4-L5 ( n = 12). 74% were posterolateral disc herniations and 22% were central. Mean preoperative, postoperative and total sick leave was 37.9 (1–109), 57.7 (28–175) and 95.6 (35–203) days respectively. An intraoperative complication rate of 2% was seen, while no infectious complications were reported. All patients returned to work, most of them to the same work (88%). 10% received work compensation. During follow up, 32% (16/50) required a new period of sick leave with a mean sick free time of 64.4 (4–135) months. 8 of these were due to a new episode of low back pain. The rest were 6 recurrent disc herniations and 2 other level disc herniations that required new surgery. At 5, 10 and more than 15 years of follow-up recurrence rate was 8%, 12% and 12% respectively, while chronic low back pain was 8%, 10% and 12% respectively. Psychological disorders found in 18% patients were associated with longer sick leave (62.8 versus 56.6 days. p &lt; 0.05) and higher need of work compensation (33% versus 4.9%, p &lt; 0.05). Patients with preoperative infiltrations (33/50) required more new periods of sick leave (33% versus 5.9%, p &lt; 0.05). Age, type of work, previous low back pain episodes, disc herniation characteristics and preoperative sick leave showed no statistically significant association with postoperative evolution. Conclusion As found in previous study, the presence of physiological disorders, also known as non-organic symptoms, and preoperative infiltrations were associated with worse results after lumbar discectomy. This manifested as longer sick leave periods and higher need of work compensation. Age, type of work, disc herniation characteristics and preoperative sick leave did not represent bad prognostic factors. Disc herniation recurrence rate increased from 8% at 5 years of follow-up to 12% at 10 and over 15 years of follow-up. This recurrence rate is similar to the one reported in literature. Ten percent of postoperative chronic low back pain at 10 years and 12% with more than 15 years of follow-up was observed.

Unilateral Approach for Bilateral Microsurgical Decompression of Lumbar Spinal Stenosis: Synopsis of 15 Years of Experience with this Surgical Method

Introduction The surgical aim in the treatment of symptomatic lumbar spinal stenosis is the relief of the patient's complaints by an adequate neural decompression. In a preliminary cadaver study the unilateral laminotomy for bilateral access to the lumbar spinal canal was investigated, and the experiences were evaluated in a clinical study. Material and Methods Microsurgical decompression was performed by partial resection of the ipsilateral facet, the medial portion of the laminar arch, the contralateral facet and by complete removal of the ligamentum flavum bilaterally. Anatomical, radiological and morphometrical studies on 4 adult cadaver spine specimens have proved the feasibility of this unilateral approach. Complete bilateral flavectomy and partial bilateral facetectomy were the essential surgical steps for an adequate operative decompression. The clinical practicability in the treatment of lumbar spinal stenosis was initially confirmed in 254 patients. Results The postoperative morphometric evaluation in the cadaver study clearly demonstrates that bilateral ligamentectomy and recess decompression were adequately and successfully achieved via unilateral approach. The clinical evaluation of this technique was performed in 254 patients with symptomatic mono- or multisegmental lumbar stenosis. Postoperatively, 229 of the 254 patients with neurogenic claudication (90.2%) demonstrated a marked improvement of the walking distance. The follow-up of 249 patients (mean follow-up time was 37 months) demonstrated an excellent result without pain in 77 patients (30.9%); a good outcome with mild residual pain, but a normal working capacity in 130 patients (52.2%); and a fair outcome with unchanged postoperative low-back pain but markedly improved working capacity and walking distance in 41 patients (16.4%). There was only one patient with surgically induced, permanent neurological deterioration (0.5%). In nine patients, an inadvertent dural tear occurred, and due to unchanged symptoms three patients with a multisegmental stenosis had to be re-operated on at an additional level. During the past 15 years the author has experience with this method in over 1600 microsurgical decompression procedures. Conclusion Unilateral laminotomy and bilateral spinal canal decompression represents a safe, effective and minimally invasive surgical method and meanwhile is a routine microsurgical strategy for the treatment of patients with lumbar spinal stenosis.