Transforaminal percutaneous endoscopic discectomy in the treatment of far-lateral lumbar disc herniations in children

Purpose

The use of transforaminal percutaneous endoscopic discectomy for the treatment of far-lateral lumbar disc herniations has been applied mostly in adults. However, transforaminal percutaneous endoscopic discectomy in children has probably been rarely documented. The aim of this study was to assess the efficacy of transforaminal percutaneous endoscopic discectomy in the treatment of far-lateral lumbar disc herniations in children.

Methods

Overall, 12 cases of far-lateral lumbar disc herniations were treated with the procedure of transforaminal percutaneous endoscopic discectomy between January 2010 and December 2014. There were seven male and five female children included, with an average age of 12.6 years (11–16 years). Pre-operative and post-operative (6 weeks, 6 months and 12 months) clinical outcome data (back and leg visual analog scale [VAS] and Macnab criteria) were collected along with clinical assessments of motor strength (graded 0–5).

Results

All patients were discharged to home on the same day of surgery. The average leg VAS score improved from 8.6?±?1.6 to 2.1?±?0.4 (p?<?0.005). Six patients had excellent outcomes, five had good outcomes, one had fair outcomes, and none had poor outcomes, according to the Macnab criteria. Eleven of 12 patients had excellent or good outcomes, for an overall success rate of 91.6 %. No patients required re-operation. There were no incidental durotomies, infections, vascular or visceral injuries. There was one complication, a case of leg numbness caused by ganglion injury. The numbness improved after two weeks. After three months, it was obvious that the total area of numbness in the legs had become smaller. At last follow-up, the patient had no pain, and only a few areas with numbness remained and did not affect the patient’s activities of daily living.

Conclusions

Transforaminal percutaneous endoscopic discectomy achieved satisfactory results for children with far-lateral lumbar disc herniations.

     

Irrigation endoscopic discectomy: a novel percutaneous approach for lumbar disc prolapse

Purpose

The purpose of this study is to present a new endoscopic procedure, aiming to achieve the success rate equivalent to microsurgical discectomy, while addressing the drawbacks and limitations of other percutaneous techniques.

Methods

A series of 43 patients with uncontained lumbar disc herniation underwent surgery with irrigation endoscopic discectomy (IED). The endoscope and instruments are placed directly over the surface of the lamina through two posterior skin portals 5 mm each without any muscle retraction or dilatation. Pump irrigation is used for the opening of a potential working space. The rest of the procedure is performed endoscopically like the standard microsurgical discectomy.

Results

Outcome according to modified Macnab criteria was excellent in 78 %, good in 17 %, and poor in 5 % of patients. VAS for leg pain dropped from 78 preoperatively to 7, and the Oswestry Low-Back Pain Disability Questionnaire dropped from 76 to 19. The mean time for postoperative ambulation was 4 h, hospital stay was 8 h, and for return to work was 7 days.

Conclusions

Preliminary clinical experience with IED shows it to be as effective as microsurgical discectomy, and in comparison to other percutaneous procedures addressing noncontained herniations, a reduction in the cost, technical difficulty and surgical invasiveness has been demonstrated.     

Surgical technique and effectiveness of microendoscopic discectomy for large uncontained lumbar disc herniations: a prospective,randomized, controlled study with 8 years of follow-up

Background

There is a long-held concept among spine surgeons that endoscopic lumbar discectomy procedures are reserved for small-contained disc herniation; 8-year follow-up has not been reported. The purpose of this study is to assess microendoscopic discectomy (MED) in patients with large uncontained lumbar disc herniation (the antero-posterior diameter of the extruded fragment is 6–12 mm or more on axial cuts of MRI) and report long-term outcome.

Methods

One hundred eighty-five patients with MED or standard open discectomy underwent follow-up for 8 years. Primary (clinical) outcomes data included Numerical Rating Scale (NRS) for back and leg symptoms and Oswestry Disability Index (ODI) to quantify pain and disability, respectively. Secondary (objective) outcomes data included operative time, blood loss, postoperative analgesics, length of hospital stay, time to return to work, reoperation and complication rate, patient satisfaction index (PSI), and modified (MacNab) criteria.

Results

At the end of the follow-up, the leg pain relief was statistically significant for both groups. NRS back pain, ODI, PSI and MacNab criteria showed significant deterioration for control group. Secondary outcomes data of MED group were significantly better than the control group.

Conclusions

Large, uncontained, lumbar disc herniations can be sufficiently removed using MED which is an effective alternative to open discectomy procedures with remarkable long-term outcome. Although the neurological outcome of the two procedures is the same, the morbidity of MED is significantly less than open discectomy. Maximum benefit can be gained if we adhere to strict selection criteria. The optimum indication is single- or multi-level radiculopathy secondary to a single-level, large, uncontained, lumbar disc herniation.     

Association of facet tropism with lumbar disc herniation

Purpose

Facet tropism is defined as asymmetry between left and right facet joints and is postulated as a possible cause of disc herniation. In the present study, the authors used a 3-T MRI to investigate the association between facet tropism and lumbar disc herniation at a particular motion segment. They also examined whether the disc herniated towards the side of the more coronally oriented facet joint.

Methods

Sixty patients (18–40 years) with single level disc herniation (L3–L4, L4–L5, or L5–S1) were included in the study. Facet angles were measured using MRI of 3-T using the method described by Karacan et al. Facet tropism was defined as difference of 10° in facet joint angles between right and left sides. Normal disc adjacent to the herniated level was used as control. We also examined if disc herniated towards the side of more coronally oriented facet.

Results

Twenty-five herniations were at L4–L5 level and 35 at L5–S1. Statistical analysis was performed using the Fischer Exact Test. At L4–L5 level, 6/25 cases had tropism compared to 3/35 controls (p = 0.145). At L5–S1 level, 13/35 cases had tropism as compared to 1/21 controls (p = 0.0094). Of 19 cases having tropism, the disc had herniated towards the coronally oriented facet in six (p = 0.11).

Conclusion

The findings of the study suggest that facet tropism is associated with lumbar disc herniation at the L5–S1 motion segment but not at the L4–L5 level.     

Microendoscopic discectomy versus open discectomy for lumbar disc herniation: a meta-analysis

Purpose

To compare the outcomes of microendoscopic discectomy and open discectomy for patients with lumbar disc herniation.

Methods

An extensive search of studies was performed in PubMed, Medline, Embase, Cochrane library and Google Scholar. The following outcome measures were extracted: visual analogue scale (VAS), Oswestry disability index (ODI), complication, operation time, blood loss and length of hospital stay. Data analysis was conducted with RevMan 5.0.

Results

Five randomized controlled trials involving 501 patients were included in this meta-analysis. The pooled analysis showed that there was no significant difference in the VAS, ODI or complication between the two groups. However, compared with the open discectomy, the microendoscopic discectomy was associated with less blood loss [WMD = ?151.01 (?288.22, ?13.80), P = 0.03], shorter length of hospital stay [WMD = ?69.33 (?110.39, ?28.28), P = 0.0009], and longer operation time [WMD = 18.80 (7.83, 29.76), P = 0.0008].

Conclusions

Microendoscopic discectomy, which requires a demanding learning curve, may be a safe and effective alternative to conventional open discectomy for patients with lumbar disc herniation.

     

Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis

Purpose

Assessing the benefits of surgical treatments for sciatica is critical for clinical and policy decision-making. To compare minimally invasive (MI) and conventional microdiscectomy (MD) for patients with sciatica due to lumbar disc herniation.

Methods

A systematic review and meta-analysis of controlled clinical trials including patients with sciatica due to lumbar disc herniation. Conventional microdiscectomy was compared separately with: (1) Interlaminar MI discectomy (ILMI vs. MD); (2) Transforaminal MI discectomy (TFMI vs. MD). Outcomes: Back pain, leg pain, function, improvement, work status, operative time, blood loss, length of hospital stay, complications, reoperations, analgesics and cost outcomes were extracted and risk of bias assessed. Pooled effect estimates were calculated using random effect meta-analysis.

Results

Twenty-nine studies, 16 RCTs and 13 non-randomised studies (n = 4,472), were included. Clinical outcomes were not different between the surgery types. There is low quality evidence that ILMI takes 11 min longer, results in 52 ml less blood loss and reduces mean length of hospital stay by 1.5 days. There were no differences in complications or reoperations. The main limitations were high risk of bias, low number of studies and small sample sizes comparing TF with MD.

Conclusions

There is moderate to low quality evidence of no differences in clinical outcomes between MI surgery and conventional microdiscectomy for patients with sciatica due to lumbar disc herniation. Studies comparing transforaminal MI with conventional surgery with sufficient sample size and methodological robustness are lacking.     

Anterior discectomy and total disc replacement for three patients with multiple recurrent lumbar disc herniations

Background context

Although results of primary discectomy are generally excellent with relief of leg pain, recurrent lumbar disc herniation is relatively common ranging from 5% to 25%. Patients with recurrent herniation may undergo revision surgery; however, this carries with it increased risks and lower success rates. Many surgeons will advocate a fusion in addition to repeat discectomy after the third recurrent herniated disc. With the approval of lumbar total disc arthroplasty, there now exists another option for the patient with three or more recurrent disc herniations to preserve motion, theoretically decrease the rate of adjacent-level disease, and ameliorate the patient’s symptoms.

Purpose

The purpose of this case report is to describe our experience using total disc replacement (TDR) in three patients after prior partial hemilaminectomy and discectomy for the treatment of a third and fourth recurrent lumbar disc herniation.

Study design

This article is a report of three cases from a spine specialty center describing an alternative surgical technique for patients with multiple recurrent lumbar disc herniation.

Methods

Comprehensive chart review of three patients with recurrent lumbar herniation who underwent TDR.

Results

Anterior discectomy and TDR were undertaken, and at most recent follow-up (8–12 months), all patients had improvement of their visual analog scale and Oswestry Disability Index. No patient had postoperative complications or reoperation.

Conclusions

Recurrent disc herniation is a relatively common problem that may be difficult to treat. Traditionally, a patient presenting with three or more recurrent disc herniation may likely have undergone revision discectomy with fusion. The current case report suggests that TDR may be an alternative option in select patients.     

Full endoscopic contralateral transforaminal discectomy for distally migrated lumbar disc herniation

Background  

Discectomy of distally, inferiorly migrated disc herniations below midpedicle level of the vertebral body in the lower lumbar spine is known to be very difficult by endoscopy. The purpose of this study was to introduce the technical possibility of percutaneous endoscopic lumbar discectomy using a contralateral transforaminal approach for distally migrated disc herniation.     

Exiting root injury in transforaminal endoscopic discectomy: preoperative image considerations for safety

Purpose

To evaluate the clinical and radiological risk factors for exiting root injuries during transforaminal endoscopic discectomy.

Methods

We retrospectively examined cohort data from 233 patients who underwent percutaneous endoscopic lumbar discectomy for lumbar disc herniation between January 1st, 2010 and December 31st, 2011. We divided the patients into the two groups: those who presented a postoperative exiting root injury, such as postoperative dysesthesia or motor weakness (Group A, n = 20), and those who did not suffer from a root injury (Group B, n = 213). We examined the clinical and radiological factors relating exiting root injuries. We measured the active working zone with the exiting root to the upper facet distance (Distance A), the exiting root to disc surface distance at the lower facet line (Distance B) and the exiting root to the lower facet distance (Distance C) in magnetic resonance imaging (MRI).

Results

Group A exhibited a shorter Distance C (6.4 ± 1.5 versus 4.4 ± 0.8 mm, p < 0.001) and a longer operation time (67.9 ± 21.8 versus 80.3 ± 23.7 min, p = 0.017) relative to Group B. The complication rate decreased by 23 % per each 1-mm increase in Distance C (p = 0.000). In addition, the complication rate increased 1.027-fold per each 1-min increase in the operation time (p = 0.027).

Conclusion

We recommend measuring the distance from the exiting root to the facet at the lower disc level according to a preoperative MRI scan. If the distance is narrow, an alternative surgical method, such as microdiscectomy or conventional open discectomy, should be considered.     

Reoperation after lumbar disc surgery in two hundred and seven patients

Purpose

The purpose of this study was to compare the causes and characteristics of reoperations after different primary operations for lumbar disc herniation (LDH).

Methods

Out of a series of 5,280 patients who underwent operations for LDH between 2001 and 2012, 207 patients (135 male and 72 female, mean age 47.7 years) underwent primary and revision operations, which were included in this study. The following clinical parameters were retrospectively assessed: the primary surgical methods, the intervals between primary and revision operations, and surgical findings in the revisions.

Results

In total, 232 lumbar discs underwent reoperations. One hundred and nineteen reoperations were performed after microendoscopic discectomy (MED group), 68 after percutaneous endoscopic lumbar discectomy (PELD group) and 45 after open disc surgery (open group). The locations of revision operations had priority over those of primary surgery, with a moderate correlation (kappa coefficient = 0.533). A total of 46.6 % of reoperations were performed within 0.5 years after primary surgery, and 35.3 % were performed between one and five years. Real recurrent herniation (homolateral herniations at the same level) was significantly more common than other reoperative surgical findings (70.6 % in PELD group, 47.1 % in MED group, 37.8 % in open group). The overall mean interval until revision surgery was 18.9 months (8.1 months in the PELD group vs. 19.7 months in the MED group vs. 33.1 months in the open group, p < 0.01).

Conclusions

For LDH, real recurrent herniation was the most common cause of reoperations, and more reoperations for real recurrent herniations and shorter intervals were found after minimally invasive endoscopic discectomy than after open disc surgery.     

Percutaneous endoscopic treatment of foraminal and extraforaminal disc herniation at the L5-S1 level

Background  

Microsurgery of foraminal and extraforaminal disc herniation at the L5-S1 level remains a challenge because of the limited access by a high iliac crest, the sacral ala, large transverse processes of L5 and hidden disc fragments lateral to the zygapophyseal joint. Our aim was to present the outcome of percutaneous endoscopic lumbar discectomy (PELD) of these lateral and far lateral disc herniations at the L5-S1 level using the newly described foraminal retreat technique in a group of patients with similar preoperative diagnostic studies.     

A predictive model for disability in patients with lumbar disc herniation

Background

Lumbar disc herniation may influence patients’ daily activities and social interactions; however, no predictive models of disability could be found for patients with lumbar disc herniation. We aimed to explore predictive factors for disability in patients with lumbar disc herniation.

Methods

The sample included 216 patients recruited from the orthopedic outpatient clinics at a medical center in northern Taiwan. Data were collected on patients’ pain, fatigue, depression, disability, and demographics. Hierarchical multiple regression analysis was used in model verification. Path analysis was used to investigate causal relationships between disability and other factors.

Results

In path analysis, the most influential factor affecting the disability level was the pain level (standardized regression coefficient, b = 0.746), followed by the fatigue level (b = 0.138) and depression level (b = 0.100). The depression level was directly affected by the fatigue level (b = 0.416) and the pain level (b = 0.367), the fatigue level was directly affected by the pain level (b = 0.538), and the pain level was directly affected by age (b = 0.140) and previous surgery (b = 0.260).

Conclusions

We recommend that health-care providers regularly assess and treat pain and depression to reduce/prevent disability among patients with lumbar disc herniation, even among those who are apparently functioning well in the community.     

Comparison of early and late percutaneous endoscopic lumbar discectomy for lumbar disc herniation

Background

The optimal timing for percutaneous endoscopic lumbar discectomy (PELD) in cases of lumbar disc herniation (LDH) is debatable. This retrospective study sought to determine which category of PELD surgical intervention time resulted in greater improvement in clinical outcomes.

Methods

We retrospectively reviewed the medical records of 145 patients who underwent PELD for single-level LDH. The patients were divided into three categories according to the duration of leg pain before surgery, the early and late group being symptomatic for ≤3 months and >3 months, ≤6 months and >6 months, ≤12 months and >12 months. Surgical time, blood loss, postoperative hospital stay, hospitalization cost, rates of reoperation due to surgical failure, Macnab criteria assessment, visual analogue scale (VAS) of back pain, leg pain and numbness, Japanese orthopedic association low back pain score (JOA) before and after surgery were compared.

Results

No significant differences were found between the early and late groups according to different categories in patients’ demographics, surgical time, blood loss, preoperative and postoperative VAS (lower-back pain, leg pain and numbness) scores, JOA scores and distribution of Macnab criteria assessment. Early PELD surgical intervention did not result in greater improvement of clinical outcomes. Later surgical intervention resulted in about one-third surgical failure rates for patients being symptomatic for >6 months (≤6 months, 11/96, 11.5 %; >6 months, 2/49, 4.1 %; P?=?0.245) and >12 months (≤12 months, 12/120, 10.0 %; >12 months, 1/25, 4.0 %; P?=?0.568) of the early surgical intervention groups. Significant difference was observed between the comorbidities and non-comorbidities group in the rate of reoperation (P?=?0.040).

Conclusions

Early PELD surgical intervention did not result in greater improvement of clinical outcomes for patients with lumbar disc herniation. Later surgical intervention resulted in less failure rates for patients than the early surgical intervention groups. PELD performed when the leg pain before surgery being symptomatic for >6 months may be good for avoiding surgical failure and reducing the duration of leg pain.     

Clinical assessment of a CMC/PEO gel to inhibit postoperative epidural adhesion formation after lumbar discectomy: a randomized, control study

Purpose

To evaluate effectiveness of carboxymethylcellulose/polyethylene oxide (CMC/PEO) gel in improving clinical outcomes after the first-time lumbar discectomy.

Method

Ninety-three patients with herniated lumbar disc at L4–L5 or L5–S1 were enrolled and randomized into two groups: CMC/PEO gel treatment group and control group. All the patients underwent laminotomy and discectomy by posterior approach. The preoperative and postoperative Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) scores for lower-back pain and leg pain were analyzed and compared between two groups at 30- and 60-day time points.

Results

No patient presented with any clinically measurable adverse event during surgery. There were no significant differences between the treated group and the control group on the preoperative ODI and VAS scores. In general, the ODI and VAS scores decreased in both groups at all the time points. At the 30-day time point, the VAS scores for back pain and leg pain and the ODI scores in treatment group were lower by 9.9 % (P = 0.0302), 27.0 % (P = 0.0002) and 16.3 % (P = 0.0007) than those in control group. And at the 60-day time point, the ODI and VAS scores further decreased in both groups. The VAS scores for leg pain in treatment group were lower by 4.5 % than that in the control group (P = 0.0149). However, no significant difference was detected between two groups on the ODI and VAS scores for back pain.

Conclusions

The results demonstrated that CMC/PEO gel is effective in reducing posterior dural adhesions in the spine with no apparent safety issues. It can improve patients’ postoperative clinical outcome.     

Relationship between neovascularization and degenerative changes in herniated lumbar intervertebral discs

Purpose

Lumbar disc degeneration may be associated with intensity of neovascularization in disc herniations. Our study was designed to evaluate how much the severity of histodegeneration is related to the development of neovascularization and to the level of pleiotrophin in the herniated lumbar discs.

Methods

Surgically excised lumbar disc specimens were obtained from 29 patients with noncontained (i.e., extruding through the posterior longitudinal ligament) and 21 patients with contained disc herniations. The histodegeneration scores and levels of neovascularization were estimated according to semiquantitative analysis in lumbar disc and endplate samples. Immunohistochemical staining were performed to identify the newly formed blood vessels and to detect the presence of pleiotrophin in the specimens.

Results

Higher levels of disc and endplate neovascularity were registered in noncontained herniations. The level of neovascularization was significantly related to the score of histodegeneration in the herniated disc tissues but not in the endplate specimens. Both contained and noncontained herniations had the highest values of histodegeneration in conjunction with the highest level of neovascularization but the relations between neovascularity and degenerative changes remained to be significant only in the group of noncontained herniations. Registration or frequency of pleiotrophin positive cells did not correlate significantly with histodegeneration or level of neovascularization in the disc samples.

Conclusion

Severe histodegeneration of the lumbar disc herniations is associated with enhanced neovascularization and potentially also spontaneous regression of the herniated tissue.     

The translaminar approach for cranially extruded lumbar disc herniations

Objective

To remove extruded disc fragments impinging the exiting root. To spare the interlaminar space and the facet joint.

Indication

Cranially migrated disc herniation.

Contraindication

Severe spinal canal stenosis.

Surgical technique

Microscope from skin to skin, 25 mm skin incision about 5 mm off the midline, conventional subperiosteal route or transmuscular access by blunt splitting the multifidus muscle. A translaminar hole (diameter 10 mm) is drilled off. The epidural exploration starts along the thecal sac until the axilla of the exiting root is reached. An extruded or subligamentous disc fragment(s) is removed. If an extensive annular perforation is detected, the disc space should be cleared (20% of the cases).

Postoperative management

Same day mobilization.

Results

A total of 84 patients (46 men) underwent the translaminar approach. The mean age was 57 years (range 27–80 years). Follow-up examinations by an independent observer at 1 and 6 weeks; 3, 6 and 12 months and once yearly thereafter (mean follow-up 27 months). Extruded (61%) and subligamentous (39%) disc fragments were found. In 4 cases the translaminar hole was enlarged to a laminotomy. In 12 patients the disc space was cleared. The outcome (MacNab criteria) was excellent (67%), good (27%), fair (5%), and poor (1%). The incidence of recurrent disc herniations was 7%.     

The distribution of infection with <Emphasis Type="Italic">Propionibacterium acnes</Emphasis> is equal in patients with cervical and lumbar disc herniation

Background

Cervical and back pains are important clinical problems affecting human populations globally. It is suggested that Propionibacterium acnes (P. acnes) is associated with disc herniation. The aim of this study is to evaluate the distribution of P. acnes infection in the cervical and lumbar disc material obtained from patients with disc herniation.

Methods and material

A total of 145 patients with mean age of 45.21 ± 11.24 years who underwent micro-discectomy in cervical and lumbar regions were enrolled into the study. The samples were excited during the operation and then cultured in the anaerobic incubations. The cultured P. acnes were detected by 16S rRNA-based polymerase chain reaction.

Results

In this study, 145 patients including 25 cases with cervical and 120 cases with lumbar disc herniation were enrolled to the study. There was no significant difference in the age of male and female patients (p = 0.123). P. acnes infection was detected in nine patients (36%) with cervical disc herniation and 46 patients (38.3%) with lumbar disc herniation and no significant differences were reported in P. acnes presence according to the disc regions (p = 0.508.). Moreover, there was a significant difference in the presence of P. acnes infection according to the level of lumbar disc herniation (p = 0.028).

Conclusion

According to the results, the presence of P. acnes is equal in patients with cervical and lumbar disc herniation. There was a significant difference in the distribution of P. acnes infection according to level of lumbar disc herniation.

Level of Evidence

II

     

Postdural disc herniation at L5/S1 level mimicking an extradural spinal tumor

Introduction

Postdural disc herniation has been documented rarely and the pathogenesis is still unknown. The average age of postdural disc herniations is between 50 and 60 years, and the sites most frequently affected by postdural lumbar disc herniations are L3–L4 and L4–L5, only less than 10 % in L5–S1. Although magnetic resonance imaging (MRI) is a useful tool in the diagnosis of this disease, the postdural disc herniation is usually misdiagnosed as extradural spine tumor preoperatively. The definitive diagnosis is made during operation or according to the postoperative pathology.

Methods

In this article, we described here a 48-year-old male patient who presented with intermittent pain in the low back and frequent urination for 4 years as well as hypesthesia and pain of the left lower extremity for 1 month.

Results

A standard total laminectomy was performed and the histopathological diagnosis was consistent with a degenerated intervertebral disc. The patient presented significant relief of the pain and of the neurological symptoms, but no improvement of frequent urination, in the postoperative period.

Conclusions

The diagnosis of postdural disc herniations is very difficult and mainly based on intraoperative and histopathological results. Early surgical intervention is important to relieve symptoms and prevent severe neurological deficits.

     

Complications of lumbar disc herniations following trans-sacral epiduroscopic lumbar decompression: a single-center,retrospective study

Background

Trans-sacral epiduroscopic lumbar decompression (SELD) is an emerging procedure for the treatment of lumbar disc herniation (LDH), with favorable outcomes having been reported. However, the complications associated with SELD have not been comprehensively evaluated to date. Therefore, the aim of our study was to describe the incidence rate, types, and characteristics of complications following SELD and management outcomes.

Methods

Retrospective analysis of the surgical and clinical outcomes for 127 patients (average age, 42.2?±?15.2 years) who underwent SELD for LDH at L2-3, L3-4, L4-5, and/or L5-S1, performed by a single experienced spine surgeon at a single center, between January 2015 and April 2017, was conducted.

Results

All procedures were successful, with a mean follow-up of 12.3?±?2.3 months. Complications were identified in 8 patients (6.3%), including 3 cases of incomplete decompression (2.4%), 2 cases of recurrent disc herniation (1.6%), and one case each of hematoma, dural tearing, and subchondral osteonecrosis (0.8%). Among these cases with complications, only 2 cases with incomplete decompression and one case with recurrent LDH did not improve with conservative treatment and required re-operation using an open approach. The rate of complications decreased from 12.6% when considering only the first 50 cases to 2.6% for cases 51–127.

Conclusions

Incomplete decompression, recurrent herniation, epidural hematoma, dural tear, and subchondral osteonecrosis were identified as complications of SELD, although the overall rate of complications was low. Practice with the procedure and careful patient selection can lower the risk of complications.

     

Does nuclear tissue infected with bacteria following disc herniations lead to Modic changes in the adjacent vertebrae?

Purpose

To investigate the prevalence of infected herniated nucleus material in lumbar disc herniations and to determine if patients with an anaerobic infected disc are more likely to develop Modic change (MC) (bone oedema) in the adjacent vertebrae after the disc herniation. MCs (bone oedema) in vertebrae are observed in 6 % of the general population and in 35–40 % of people with low back pain. These changes are strongly associated with low back pain. There are probably a mechanical cause and an infective cause that causes MC. Several studies on nuclear tissue from herniated discs have demonstrated the presence of low virulent anaerobic microorganisms, predominantly Propionibacterium acnes, in 7–53 % of patients. At the time of a herniation these low virulent anaerobic bacteria may enter the disc and give rise to an insidious infection. Local inflammation in the adjacent bone may be a secondary effect due to cytokine and propionic acid production.

Methods

Patients undergoing primary surgery at a single spinal level for lumbar disc herniation with an MRI-confirmed lumbar disc herniation, where the annular fibres were penetrated by visible nuclear tissue, had the nucleus material removed. Stringent antiseptic sterile protocols were followed.

Results

Sixty-one patients were included, mean age 46.4 years (SD 9.7), 27 % female. All patients were immunocompetent. No patient had received a previous epidural steroid injection or undergone previous back surgery. In total, microbiological cultures were positive in 28 (46 %) patients. Anaerobic cultures were positive in 26 (43 %) patients, and of these 4 (7 %) had dual microbial infections, containing both one aerobic and one anaerobic culture. No tissue specimens had more than two types of bacteria identified. Two (3 %) cultures only had aerobic bacteria isolated. In the discs with a nucleus with anaerobic bacteria, 80 % developed new MC in the vertebrae adjacent to the previous disc herniation. In contrast, none of those with aerobic bacteria and only 44 % of patients with negative cultures developed new MC. The association between an anaerobic culture and new MCs is highly statistically significant (P = 0.0038), with an odds ratio of 5.60 (95 % CI 1.51–21.95).

Conclusion

These findings support the theory that the occurrence of MCs Type 1 in the vertebrae adjacent to a previously herniated disc may be due to oedema surrounding an infected disc. The discs infected with anaerobic bacteria were more likely (P < 0.0038) to develop MCs in the adjacent vertebrae than those in which no bacteria were found or those in which aerobic bacteria were found.