Anatomical Proximity Between Sciatic Nerve and Ischial Spine and its Relationship to the Development of Deep Gluteal Pain Syndrome.

OBJECTIVE: Deep gluteal syndrome (DGS) is a medical diagnosis in which the pathoanatomy of the subgluteal space contributes to pain. The growing recognition that gluteal neuropathies can be associated with the presence of a bone-neural conflict with irritation or compression may allow us to shed some light on this pathology. This study aims to determine whether the location of the sciatic nerve (SN) in relation to the ischial spine (IS) contributes to the development of DGS. METHODS: The SN - IS relationship was analyzed based on magnetic resonance imaging (MRI) in 15 surgical patients (SPs), who underwent piriformis release, and in 30 control patients who underwent MRI of the pelvis for reasons unrelated to sciatica. The SN exit from the greater sciatic foramen was classified as either zone A (medial to the IS); zone B (on the IS); or zone C (lateral to the IS). RESULTS: The SN was significantly closer to the IS in SPs than in MRI controls (P = 0.014). When analyzing patients of similar age, SNs in SPs were significantly closer (P = 0.0061) to the IS, and located in zone B significantly more (P = 0.0216) as compared to MRI controls. Patients who underwent surgery for piriformis release showed a significant decrease in pain postoperatively (P < 0.0001). CONCLUSIONS: The results from this study suggest that the relationship between the IS and SN may play a role in the development of DGS. This may also help establish which patients would benefit more from surgical intervention.

MRI findings correlate with difficult dissection during proximal hamstring repair and with postoperative sciatica.

OBJECTIVE: This study examines the correlation between MRI findings and difficult dissection during proximal primary hamstring repair and postoperative sciatica. MATERIALS AND METHODS: A total of 32 cases of surgically repaired hamstring tendon tears that underwent preoperative and postoperative MRI were divided into sciatica (n = 12) and control (n = 20) groups based on the presence or absence of postoperative sciatica. Cases were scored by two blinded musculoskeletal radiologists for imaging features associated with difficult surgical dissection and the development of subsequent sciatica. Intra- and interrater agreements, as well as correlation of MRI findings with symptoms (odds ratio, OR), were calculated. RESULTS: On preoperative MRI, diffuse hamstring muscle edema pattern suggestive of active denervation (OR 9.4-13.6), and greater sciatic perineural scar circumference (OR 1.9-2) and length (OR 1.2-1.3) were significantly correlated with both difficult dissection and postoperative sciatica. Preoperatively, a greater number of tendons torn (OR 3.3), greater tear cross-sectional area (CSA, OR 1.03), and increased nerve T2-weighted signal (OR 3.2) and greater perineural scar thickness (OR 1.7) were also associated with difficult dissection, but not postoperative sciatica. On postoperative MRI, hamstring denervation, sciatic nerve tethering to the hamstring tendon, and development of perineural scar and greater perineural scar extent were all significantly correlated with postoperative sciatica. CONCLUSION: Preoperative hamstring MRI demonstrates findings predictive of difficult sciatic nerve dissection; careful MRI evaluation of the nerve and for the presence and extent of perineural scar is important for preoperative planning. Preoperative and postoperative MRI both depict findings that correlate with postoperative sciatica.

Practice variation in surgical treatment for lumbar degenerative disc disease: exploring regional and hospital factors influencing surgical rates.

The presence of significant, unwarranted variation in treatment suggests that clinical decision making also depends on where patients live instead of what they need and prefer. Historically, high practice variation in surgical treatment for lumbar degenerative disc disease (LDDD) has been documented. This study aimed to investigate current regional variation in surgical treatment for sciatica resulting from LDDD. We conducted a retrospective, cross-sectional analysis of all Dutch adults (>18 years) between 2016 and 2019. Demographic data from Statistics Netherlands were merged with a nationwide claims database, covering over 99% of the population. Inclusion criteria comprised LDDD diagnosis codes and relevant surgical codes. Practice variation was assessed at the level of postal code areas and hospital service areas (HSAs). Multivariable logistic regression analysis was employed to identify variables associated with surgical treatment. Among the 119,148 hospital visitors with LDDD, 14,840 underwent surgical treatment. Practice variation for laminectomies and discectomies showed less than two-fold variation in both postal code and HSAs. However, instrumented fusion surgery demonstrated a five-fold variation in postal code areas and three-fold variation in HSAs. Predictors of receiving surgical treatment included opioid prescription and patient referral status. Gender differences were observed, with males more likely to undergo laminectomy or discectomy, and females more likely to receive instrumented fusion surgery. Our study revealed low variation rates for discectomies and laminectomies, while indicating a high variation rate for instrumented fusion surgery in LDDD patients. High-quality research is needed on the extent of guideline implementation and its influence on practice variation.

The long-term outcome of revision microdiscectomy for recurrent sciatica.

PURPOSE: To study the long-term outcome of revision microdiscectomy after classic microdiscectomy for lumbosacral radicular syndrome (LSRS). METHODS: Eighty-eight of 216 patients (41%) who underwent a revision microdiscectomy between 2007 and 2010 for MRI disc-related LSRS participated in this study. Questionnaires included visual analogue scores (VAS) for leg pain, RDQ, OLBD, RAND-36, and seven-point Likert scores for recovery, leg pain, and back pain. Any further lumbar re-revision operation(s) were recorded. RESULTS: Mean (SD) age was 59.8 (12.8), and median [IQR] time of follow-up was 10.0 years [9.0-11.0]. A favourable general perceived recovery was reported by 35 patients (40%). A favourable outcome with respect to perceived leg pain was present in 39 patients (45%), and 35 patients (41%) reported a favourable outcome concerning back pain. The median VAS for leg and back pain was worse in the unfavourable group (48.0/100 mm (IQR 16.0-71.0) vs. 3.0/100 mm (IQR 2.0-5.0) and 56.0/100 mm (IQR 27.0-74.0) vs. 4.0/100 mm (IQR 2.0-17.0), respectively; both p < 0.001). Re-revision operation occurred in 31 (35%) patients (24% same level same side); there was no significant difference in the rate of favourable outcome between patients with or without a re-revision operation. CONCLUSION: The long-term results after revision microdiscectomy for LSRS show an unfavourable outcome in the majority of patients and a high risk of re-revision microdiscectomy, with similar results. Based on also the disappointing results of alternative treatments, revision microdiscectomy for recurrent LSRS seems to still be a valid treatment. The results of our study may be useful to counsel patients in making appropriate treatment choices.

Efficiency of interlaminar uniportal endoscopic lumbar discectomy.

AIM: Prospective evaluation of the results of endoscopic lumbar discectomy. METHODS: 95 patients were consecutively enrolled in the study between 2017 and 2021. We monitored low back pain and sciatica according to the Visual Analogue Scale (VAS), the limitations in daily activities (Oswestry Disability Index, ODI), overall satisfaction according to a 0-100 % scale, and the rate of surgical complications and reoperations. RESULTS: Postoperatively, the VAS values of low back pain and sciatica decreased significantly from 5 to 1 point and from 6 to 1 point, respectively, and the pain remained in the tolerable range (VAS 1-2) throughout the follow-up period. The ODI score improved significantly from severe disability (46 %), preoperatively, to moderate disability at discharge and one month after surgery (29 % and 22 %, respectively), down to minimal disability at 3 and 12 months after surgery (12 % and 14 %, respectively). Overall patient satisfaction improved significantly at all follow-up time points (46 %, 70 %, 77 %, 80 %, and 78 %, respectively). Reoperation rate was 6.3 %. Cerebrospinal fluid leakage was observed in one case only (1.1 %). Transient postoperative perianogenital sensory impairment occurred in two patients (2.1 %). There was no evidence of surgical site infection or haematoma. CONCLUSION: Endoscopic discectomy provides significant pain relief and improves the patient's ability to perform activities of daily living, contributing to greater satisfaction. It is a safe method with a low risk of surgical and neurological complications (Tab. 3, Fig. 3, Ref. 27).

Amyloid Deposition: An Unusual Case of Deep Gluteal Syndrome and Sciatic Nerve Compression: A Case Report.

CASE: Soft-tissue amyloidomas are exceedingly rare, with only a few cases reported in the literature. There are no reports of sciatic nerve compression secondary to a soft-tissue amyloidoma. We report a unique case of a 71-year-old man with an incidentally found amyloidoma who was initially believed to have deep gluteal syndrome. He had a favorable outcome after surgical decompression. CONCLUSION: For patients who do not have classic examination and electromyography/nerve conduction findings of piriformis syndrome, providers should explore other etiologies of peripheral nerve compression including soft-tissue amyloidoma.

Full endoscopic versus open discectomy for sciatica: randomised controlled non-inferiority trial.

OBJECTIVE: To assess whether percutaneous transforaminal endoscopic discectomy (PTED) is non-inferior to conventional open microdiscectomy in reduction of leg pain caused by lumbar disc herniation. DESIGN: Multicentre randomised controlled trial with non-inferiority design. SETTING: Four hospitals in the Netherlands. PARTICIPANTS: 613 patients aged 18-70 years with at least six weeks of radiating leg pain caused by lumbar disc herniation. The trial included a predetermined set of 125 patients receiving PTED who were the learning curve cases performed by surgeons who did not do PTED before the trial. INTERVENTIONS: PTED (n=179) compared with open microdiscectomy (n=309). MAIN OUTCOME MEASURES: The primary outcome was self-reported leg pain measured by a 0-100 visual analogue scale at 12 months, assuming a non-inferiority margin of 5.0. Secondary outcomes included complications, reoperations, self-reported functional status as measured with the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery. Outcomes were measured until one year after surgery and were longitudinally analysed according to the intention-to-treat principle. Patients belonging to the PTED learning curve were omitted from the primary analyses. RESULTS: At 12 months, patients who were randomised to PTED had a statistically significantly lower visual analogue scale score for leg pain (median 7.0, interquartile range 1.0-30.0) compared with patients randomised to open microdiscectomy (16.0, 2.0-53.5) (between group difference of 7.1, 95% confidence interval 2.8 to 11.3). Blood loss was less, length of hospital admission was shorter, and timing of postoperative mobilisation was earlier in the PTED group than in the open microdiscectomy group. Secondary patient reported outcomes such as the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery, were similarly in favour of PTED. Within one year, nine (5%) in the PTED group compared with 14 (6%) in the open microdiscectomy group had repeated surgery. Per protocol analysis and sensitivity analyses including the patients of the learning curve resulted in similar outcomes to the primary analysis. CONCLUSIONS: PTED was non-inferior to open microdiscectomy in reduction of leg pain. PTED resulted in more favourable results for self-reported leg pain, back pain, functional status, quality of life, and recovery. These differences, however, were small and may not reach clinical relevance. PTED can be considered as an effective alternative to open microdiscectomy in treating sciatica. TRIAL REGISTRATION: NCT02602093ClinicalTrials.gov NCT02602093.

Quality of conscious sedation using dexmedetomidine during full-endoscopic transforaminal discectomy for sciatica: a prospective case series.

INTRODUCTION: Percutaneous transforaminal endoscopic discectomy (PTED) is increasing in popularity as a minimally invasive procedure to treat sciatica caused by lumbar disc herniation. The objective of the current study is to evaluate safety of and satisfaction with the use of local anesthesia and conscious sedation during PTED. METHODS: During a 12-month inclusion period, patients were prospectively included in this single center case series. Inclusion criteria consisted of sciatica lasting for at least 6 weeks, which was not responsive to conservative treatment. PTED was performed using dexmedetomidine as sedative and lidocaine as local anesthesia. Measurements included the numeric rating scale (NRS, from 0 to 10) for leg pain, back pain, COMI-back, and NRS for anxiety of anesthesia and perioperative continuously monitored hemodynamics. Furthermore, satisfaction with the sedation was scored by patients, surgeons, and anesthesiologists. RESULTS: Ninety-two consecutive patients were enrolled. Of all patients, 18.5% had anxiety for undergoing surgery under local anesthesia. All but one patient underwent PTED successfully. There was one case of conversion due to severe, uncontrollable back pain during surgery. Throughout the procedure, hemodynamic parameters showed no clinically relevant change compared to baseline. Anesthesiologic complications were three cases (3.4%) of self-limiting hypoxia and five cases (8.6%) of nausea and/or vomiting. Surgeons and anesthesiologists had a high satisfaction rate (> 87%) with the conscious sedation during the procedure, while satisfaction with sedation was scored 8.4 ± 2.2 by patients. CONCLUSIONS: PTED performed under local anesthesia and conscious sedation is safe and effective to treat sciatica and yields high satisfaction rates from surgeons, anesthesiologists, and patients.

Microdiscectomy for sciatica: reality check study of long-term surgical treatment effects of a Lumbosacral radicular syndrome (LSRS).

PURPOSE: It remains unclear whether the long-term results of RCTs regarding the outcome of microdiscectomy for lumbosacral radicular syndrome (LSRS) are generalizable. The purpose of this study was to determine the external validity of the outcome preseneted in RCTs after microdicectomy for LSRS in a patient cohort from a high-volume spine center. METHODS: Between 2007 and 2010, 539 patients had a single level microdiscectomy for MRI disk-related LSRS of whom 246 agreed to participate. Questionnaires included visual analogue scores (VAS) for leg pain, RDQ, OLBD, RAND-36 and Likert scores for recovery, leg and back pain. Lumbar re-operation(s) were registered. RESULTS: Mean age was 51.3, and median time of follow-up was 8.0 years. Re-operation occurred in 64 (26%) patients. Unfavorable perceived recovery was noted in 85 (35%) patients, and they had worse leg and back pain than the 161 (65%) patients with a favorable recovery: median VAS for leg pain 28/100 mm versus 2/100 mm and median VAS for back pain 9/100 mm versus 3/100 mm, respectively. In addition, the median RDQ and OLBD scores differed significantly: 9 vs 3 for RDQ and 26 vs 4 for OLBD, respectively (p < 0.001). CONCLUSION: In this cohort study, the long-term results after microdiscectomy for LSRS were less favorable than those obtained in RCTs, possibly caused by less strict patient selection than in RCTs. Our findings emphasize that patients, who do not meet the same inclusion criteria for surgery as in RCTs, should be informed about the chances of a less favorable result.

Surgeons preference for lumbar disk surgery: a discrete choice experiment.

PURPOSE: Multiple surgical techniques are practiced to treat sciatica caused by lumbar disk herniation. It is unknown which factors surgeons find important when offering certain surgical techniques. The objective of this study is threefold: 1) determine the relative weight surgeons place on various characteristics of sciatica treatment, 2) determine the trade-offs surgeons make between these characteristics and 3) identify preference heterogeneity for sciatica treatment. METHODS: A discrete choice experiment was conducted among members of two international neurosurgical organizations. Surgeons were asked on their preferences for surgical techniques using specific scenarios based on five characteristics: effectiveness on leg pain, risk of recurrent disk herniation, duration of postoperative back pain, risk of complications and recovery period. RESULTS: Six-hundred and forty-one questionnaires were filled in, the majority by neurosurgeons. All characteristics significantly influenced the preferences of the respondents. Overall, the risk of complications was the most important characteristic in the decision to opt-in or opt-out for surgery (35.7%). Risk of recurrent disk herniation (19.6%), effectiveness on leg pain (18.8%), postoperative back pain duration (13.5%) and length of recovery period (12.4%) followed. Four latent classes were identified, which was partly explained by the tenure of the surgeon. Surgeons were willing to trade-off 57.8% of effectiveness on leg pain to offer a treatment that has a 1% complication risk instead of 10%. CONCLUSION: In the context of this discrete choice experiment, it is shown that neurosurgeons consider the risk of complications as most important when a surgical technique is offered to treat sciatica, while the risk of recurrent disk herniation and effectiveness are also important factors. Neurosurgeons were prepared to trade off substantial amounts of effectiveness to achieve lower complication rates.

Bilateral ganglion cysts at L4/5 causing central canal stenosis and producing sciatica and neurogenic claudication: a case report.

Symptomatic bilateral juxtafacet ganglion cysts are relatively uncommon in the degenerated spine. The literature describes 16 cases of bilateral ganglion or synovial cysts, none reported sciatica and neurogenic claudication simultaneously. We present a case of a 60-year-old woman who presented with symptoms of bilateral sciatica and neurogenic claudication. Magnetic resonance imaging of the lumbar spine revealed bilateral lesions related to the facet joints at the L4/5 level, causing bilateral lateral recess stenosis and narrowing of the central canal due to encroachment of these bilateral lesions at the same level. She underwent an elective central canal decompression of the L4/5 level and excision of the facet cysts bilaterally with lateral recess decompression, which resulted in good relief of both the radicular and claudication symptoms.

Percutaneous transforaminal endoscopic discectomy in a nine-year-old patient with sciatica: case report, technical note and overview of the literature.

Percutaneous transforaminal endoscopic discectomy (PTED) is an alternative procedure to open microdiscectomy (OM) to treat sciatica caused by lumbar disk herniation. Even though robust evidence comparing PTED with OM is lacking, PTED is becoming increasingly popular to treat spinal disorders. In this technical report, the surgical technique and outcomes of PTED in a 9-year-old patient are described. Furthermore, an overview of the literature on full-endoscopic techniques to treat sciatica is given, showing that PTED is feasible, safe and effective to treat lumbar disk herniation in the pediatric population.

Back pain is also improved by lumbar disc herniation surgery.

Background and purpose - Indication for lumbar disc herniation (LDH) surgery is usually to relieve sciatica. We evaluated whether back pain also decreases after LDH surgery.Patients and methods - In the Swedish register for spinal surgery (SweSpine) we identified 14,097 patients aged 20-64 years, with pre- and postoperative data, who in 2000-2016 had LDH surgery. We calculated 1-year improvement on numeric rating scale (rating 0-10) in back pain (Nback) and leg pain (Nleg) and by negative binomial regression relative risk (RR) for gaining improvement exceeding minimum clinically important difference (MCID).Results - Nleg was preoperatively (mean [SD]) 6.7 (2.5) and Nback was 4.7 (2.9) (p < 0.001). Surgery reduced Nleg by mean 4.5 (95% CI 4.5-4.6) and Nback by 2.2 (CI 2.1-2.2). Mean reduction in Nleg) was 67% and in Nback 47% (p < 0.001). Among patients with preoperative pain ≥ MCID (that is, patients with significant baseline pain and with a theoretical possibility to improve above MCID), the proportion who reached improvement ≥ MCID was 79% in Nleg and 60% in Nback. RR for gaining improvement ≥ MCID in smokers compared with non-smokers was for Nleg 0.9 (CI 0.8-0.9) and -Nback 0.9 (CI 0.8-0.9), and in patients with preoperative duration of back pain 0-3 months compared with > 24 months for Nleg 1.3 (CI 1.2-1.5) and for Nback 1.4 (CI 1.2-1.5).Interpretation - LDH surgery improves leg pain more than back pain; nevertheless, 60% of the patients with significant back pain improved ≥ MCID. Smoking and long duration of pain is associated with inferior recovery in both Nleg and Nback.

[Retrospective study of surgical management of lumbosciatica in the Department of Orthopaedics in Tataouine, Tunisia: about 44 cases]. / Étude rétrospective concernant la prise en charge chirurgicale des lombosciatiques communes dans le Département d'Orthopédie de Tataouine, Tunisie: à propos de 44 cas.

Lumbosciatica is a public health problem because of its socio-professional impact. The purpose of our study is to evaluate the indication for surgical treatment and the role of each technique used. We conducted a retrospective study in the Department of Orthopaedics in Tataouine. The study involved 44 patients with common lumbosciatica and having undergone surgical treatment over the period from 2013 to 2018. The information sheet included the epidemiological data and the clinical data. The patients underwent radiological assessment including lumbar spine x-ray (frontal and lateral views) and lumbar computed scan (CT) scan which clarified the cause of sciatica. Surgical treatment was indicated after medical treatment failure, in patients with hyperalgesia and in patients with neurological complication. In our study, herniated disc was the primary cause of lumbosciatica (50% of cases) followed by lumbar spinal stenosis (25%), spondylolisthesis (22.7%) and transverse mega-apophysis of L5 vertebrae (2.3%). Traditional discectomy was the most used technique for surgical treatment of herniated disc. Eight patients had spondylolisthesis. They underwent laminectomy associated with posterior arthrodesis. Lumbar spinal stenosis was treated with laminectomy alone in 54.54% of cases. Outcome was favorable during the follow up period in 90% of cases (Visual Analog Scale 3±1 at follow-up). Surgical technique depends on etiology and imaging data on which to base the choice of arthrodesis stages.

Surgery versus Conservative Care for Persistent Sciatica Lasting 4 to 12 Months.

BACKGROUND: The treatment of chronic sciatica caused by herniation of a lumbar disk has not been well studied in comparison with acute disk herniation. Data are needed on whether diskectomy or a conservative approach is better for sciatica that has persisted for several months. METHODS: In a single-center trial, we randomly assigned patients with sciatica that had lasted for 4 to 12 months and lumbar disk herniation at the L4-L5 or L5-S1 level in a 1:1 ratio to undergo microdiskectomy or to receive 6 months of standardized nonoperative care followed by surgery if needed. Surgery was performed by spine surgeons who used conventional microdiskectomy techniques. The primary outcome was the intensity of leg pain on a visual analogue scale (ranging from 0 to 10, with higher scores indicating more severe pain) at 6 months after enrollment. Secondary outcomes were the score on the Oswestry Disability Index, back and leg pain, and quality-of-life scores at 6 weeks, 3 months, 6 months, and 1 year. RESULTS: From 2010 through 2016, a total of 790 patients were screened; of those patients, 128 were enrolled, with 64 in each group. Among the patients assigned to undergo surgery, the median time from randomization to surgery was 3.1 weeks; of the 64 patients in the nonsurgical group, 22 (34%) crossed over to undergo surgery at a median of 11 months after enrollment. At baseline, the mean score for leg-pain intensity was 7.7 in the surgical group and 8.0 in the nonsurgical group. The primary outcome of the leg-pain intensity score at 6 months was 2.8 in the surgical group and 5.2 in the nonsurgical group (adjusted mean difference, 2.4; 95% confidence interval, 1.4 to 3.4; P<0.001). Secondary outcomes including the score on the Owestry Disability Index and pain at 12 months were in the same direction as the primary outcome. Nine patients had adverse events associated with surgery, and one patient underwent repeat surgery for recurrent disk herniation. CONCLUSIONS: In this single-center trial involving patients with sciatica lasting more than 4 months and caused by lumbar disk herniation, microdiskectomy was superior to nonsurgical care with respect to pain intensity at 6 months of follow-up. (Funded by Physicians' Services Incorporated Foundation; ClinicalTrials.gov number, NCT01335646.).

Lumbar disc extrusions reduce faster than bulging discs due to an active role of macrophages in sciatica.

OBJECTIVE: This retrospective observational histological study aims to associate the size and type of disc herniation with the degree of macrophage infiltration in disc material retrieved during disc surgery in patients with sciatica. METHODS: Disc tissue of 119 sciatica patients was embedded in paraffin and stained with hematoxylin and CD68. Tissue samples were categorized as mild (0-10/cm2), moderate (10-100/cm2), and considerable (> 100/cm2) macrophage infiltration. All 119 patients received an MRI at baseline, and 108 received a follow-up MRI at 1-year. MRIs were reviewed for the size and type of the disc herniations, and for Modic changes in the vertebral endplates. RESULTS: Baseline characteristics and duration of symptoms before surgery were comparable in all macrophage infiltration groups. The degree of macrophage infiltration was not associated with herniation size at baseline, but significantly associated with reduction of size of the herniated disc at 1-year post surgery. Moreover, the degree of macrophage infiltration was higher in extrusion in comparison with bulging (protrusion) of the disc. Results were comparable in patients with and without Modic changes. CONCLUSION: Macrophage infiltration was positively associated with an extruded type of disc herniation as well as the extent of reduction of the herniated disc during 1-year follow-up in patients with sciatica. This is an indication that the macrophages play an active role in reducing herniated discs. An extruded disc herniation has a larger surface for the macrophages to adhere to, which leads to more size reduction.

Five-year Reoperation Rates and Causes for Reoperations Following Lumbar Microendoscopic Discectomy and Decompression.

STUDY DESIGN: Retrospective study of prospectively collected outcome data. OBJECTIVE: The aim of this study was to investigate reoperation cases and determine whether or not the experience period of a single surgeon was associated with the causes of reoperations following lumbar microendoscopic discectomy for disc herniation (MEDH) and microendoscopic decompression for spinal stenosis (MEDS). SUMMARY OF BACKGROUND DATA: There have been few studies that investigated reoperation cases following MEDH and MEDS. METHODS: Between June 2005 (first experience of MEDH) and September 2013, the same surgeon had been using MEDH and/or MEDS on 441 consecutive patients. The follow-up rate was 89.3%. The causes and rates of reoperations (RORs) were determined at 5 years after the initial operations. We also investigated the experience period of a single surgeon (EPS, interval between June 2005 and initial operation: median, 37 months). RESULTS: The 5-year reoperation rate for all patients combined was 12.4% (49/394). The main causes for reoperations were recurrence of disc herniation (ROR, 7.01%) and increase of postoperative spondylolisthesis and/or instability (ROR, 9/394 = 2.28%); two of the nine cases were caused by excessive decompression, and the EPSs were 11 and 16 months. The other causes for reoperations were postoperative epidural hematoma (ROR, 0.76%; median EPS, 20 months), insufficient decompression (ROR, 0.25%; EPS, 17 months), and residual segmental scoliosis (ROR, 7.69%); two segmental scoliosis cases did not provide relief from sciatica, and therefore L4/5 transforaminal interbody fusions were performed. CONCLUSION: Postoperative epidural hematoma and excessive or insufficient decompression were often observed in the initial series of patients as the causes for reoperations. We think that it is important to be aware of and prevent such potential problems in any initial series of patients, as there are limitations to any surgical indications for the use of microendoscopic decompression for degenerative segmental scoliosis because of original traction and/or kinking of nerve roots. LEVEL OF EVIDENCE: 4.