Spontaneous resorption of sequestrated intervertebral disc herniation. World Neurosurg. 2012;77:146-152. [PMID: 22154147 DOI: 10.1016/j.wneu.2011.04.021]

Three Stages on Magnetic Resonance Imaging of Lumbar Degenerative Spine

PURPOSES

To propose a new lumbar degenerative staging system using the current radiological classification system.

METHODS

A cross-sectional analysis of retrospective databases between January 2018 and December 2022 was performed. Total of 410 patients for Modic changes, paravertebral muscle fat infiltration, disc degeneration, articular process degeneration, vertebral endplate degeneration and other structures, and disc displacement, Spondylolisthesis, and stenosis, and grouped patients according to stage were assessed. Visual analog scale, Japanese Orthopaedic Association, and Oswestry Disability Index scores were used to assess low back pain strength, neurological function, and quality of life, respectively.

RESULTS

The lumbar degeneration staging system consists of 8 variables, which can be divided into 3 steps: early, middle and late, and the correlation between each variable is strong (P < 0.05). The later the staging, the worse the Japanese Orthopaedic Association, visual analog scale, and Oswestry Disability Index scores.

CONCLUSIONS

Patients with later stages have worse clinical scores. This staging system recommends a uniform classification to assess lumbar degeneration.

Prediction and Mechanisms of Spontaneous Resorption in Lumbar Disc Herniation: Narrative Review

The major symptoms of lumbar disc herniation (LDH) are low back pain, radiative lower extremity pain, and lower limb movement disorder. Patients with LDH suffer from great distress in their daily life accompanied by severe economic hardship and difficulty in self-care, with an increasing tendency in the aging population. PubMed and the Cochrane Central Register of Controlled Trials were searched for relevant studies of spontaneous resorption or regression in LDH after conservative treatment and for other potential studies, which included those from inception to June 30, 2023. The objective of this narrative review is to summarize previous literatures about spontaneous resorption in LDH and to discuss the mechanisms and influencing factors in order to assess the probability of spontaneous resorption by conservative treatment. Spontaneous resorption without surgical treatment is influenced by the types and sizes of the LDH, inflammatory responses, and therapeutic factors. If the lumbar disc herniated tissue comprises a higher percentage of cartilage or modic changes have been shown on magnetic resonance imaging (MRI), resorption in LDH is prevented. The bull's eye sign on enhanced MRI, which is a ring enhancement around a protruding disc, is a vital indicator for easy reabsorption. In addition, the type of extrusion and sequestration in LDH could forecast the higher feasibility of natural reabsorption. Moreover, the higher the proportion of protrusion on the intervertebral disc tissue within the spinal canal, the greater the likelihood of reabsorption. Therefore, which illustrates the feasibility of conservative treatments for LDH. Nonsurgical management of LDH with clinical symptoms is recommended by the authors.

[Imaging of Sequestered Lumbar Discs]

Intervertebral disc herniation is frequently encountered in radiological practice. Sequestered disc herniation occurs when the disc material undergoes degeneration and completely loses continuity with the parent nucleus pulposus. Sequestered discs can reside within and outside the spinal canal, exerting a mass effect on adjacent structures, compressing nerve pathways, and eliciting a range of clinical symptoms. In particular, sequestered discs within the dura cannot be identified without durotomy. Therefore, precise preoperative localization is crucial for surgical planning. On MRI, the signal intensity of the sequestered disc may vary due to independent degeneration processes. Additionally, most sequestered disc fragments show varying degrees of peripheral enhancement depending on the degree of angiogenesis and granulation around the isolated tissue. In this article, we review various imaging findings and the location of the sequestered disc to provide patients with an accurate diagnosis and appropriate treatment direction.

Correlation of multifidus degeneration with sex, age and side of herniation in patients with lumbar disc herniation

OBJECTIVE

The aim of this study was to determine the relationship between multifidus degeneration and sex, age and side of protrusion in patients with lumbar disc herniation(LDH).

METHODS

Data were collected from September 2015 to September 2022 from patients with L4/5 and L5/S1 LDH. A total of 104 patients (62 males and 42 females) were included in this study, and there were 35 and 69 cases of L4/5 and L5/S1 LDH, respectively. Patients were divided into 4 groups according to age: group 1 (20-29), group 2 (30-39), group 3 (40-49) and group 4 (50-59). Magnetic resonance spectroscopy analysis was used to observe the fat fraction (FF) and functional cross-sectional area (f-CSA) of the defatted multifidus muscle of the protruding side (affected side) and the nonprotruding side (healthy side) of the L4/5 and L5/S1 gaps to evaluate the relationship between multifidus degeneration and sex, age and protruding side in patients with LDH.

RESULTS

Between sexes, the FF of the multifidus muscle was significantly greater in women than in men, regardless of whether it was on the affected or healthy side of the L4/5 segment or on the affected or healthy side of the L5/S1 segment (P < 0.05). Between age groups, there was a significantly positive relationship between the change in FF (%) of the multifidus muscle in patients with LDH and age, with increasing fatty infiltration of the multifidus increasing with age (P < 0.05); notably, there was a significant difference between group 4 and the remaining three groups but no significant difference between groups 1, 2 and 3. The f-CSA of the multifidus (cm2) was negatively correlated with age, with the f-CSA of the multifidus becoming more atrophic with increasing age; specifically, there was a significant difference between group 1 and the other three groups (P < 0.05) but not between groups 2, 3 and 4. Regarding the side of the herniated disc, (1) the differences in FF and f-CSA at the L4/5 and L5/S1 levels were not statistically significant between the affected side and the healthy side in patients with lumbar disc herniation at the L4/5 segment (P > 0.05); (2) the differences in FF and f-CSA at the L5/S1 level were not statistically significant between the affected side and the healthy side in patients with LDH at the L5/S1 segment (P > 0.05); (3) the difference between FF at the L4/5 level and f-CSA and FF at the L5/S1 level was not statistically significant (P > 0.05); and (4) the f-CSA at the L5/S1 level was significantly greater on the healthy side than on the affected side (P < 0.05).

CONCLUSION

The proportion of lipoatrophy in female patients with L4/5 and L5/S1 disc herniations was greater than that in male patients. Lipoatrophy of the multifidus muscle increased with age and was significantly worse in patients over 50 years of age. The f-CSA of the multifidus muscle was negatively related to age, and the f-CSA of the multifidus muscle became more atrophic with increasing age. A comparison of degeneration showed no significant difference between the L4/5 patients and the L5/S1 patients in terms of f-CSA atrophy on the affected side of the herniated disc compared to the healthy side.

Prediction of lumbar disc herniation resorption in symptomatic patients: a prospective, multi-imaging and clinical phenotype study

BACKGROUND CONTEXT

Symptomatic lumbar disc herniations (LDH) are very common. LDH resorption may occur by a "self-healing" process, however this phenomenon remains poorly understood. By most guidelines, if LDH remains symptomatic after 3 months and conservative management fails, surgical intervention may be an option.

PURPOSE

The following prospective study aimed to identify determinants that may predict early versus late LDH resorption.

STUDY DESIGN/SETTING

Prospective study with patients recruited at a single center.

PATIENT SAMPLE

Ninety-three consecutive patients diagnosed with acute symptomatic LDH were included in this study (n=23 early resorption and n=67 late resorption groups) with a mean age of 48.7±11.9 years.

OUTCOMES MEASURE

Baseline assessment of patient demographics (eg, smoking status, height, weight, etc.), herniation characteristics (eg, the initial level of herniation, the direction of herniation, prevalence of multiple herniations, etc.) and MRI phenotypes (eg, Modic changes, end plate abnormalities, disc degeneration, vertebral body dimensions, etc.) were collected for further analysis. Lumbar MRIs were performed approximately every 3 months for 1 year from time of enrollment to assess disc integrity.

METHODS

All patients were managed similarly. LDH resorption was classified as early (<3 months) or late (>3 months). A prediction model of pretreatment factors was constructed.

RESULTS

No significant differences were noted between groups at any time-point (p>.05). Patients in the early resorption group experienced greater percent reduction of disc herniation between MRI-0-MRI-1 (p=.043), reduction of herniation size for total study duration (p=.007), and percent resorption per day compared to the late resorption group (p<.001). Based on multivariate modeling, greater L4 posterior vertebral height (coeff:14.58), greater sacral slope (coeff:0.12), and greater herniated volume (coeff:0.013) at baseline were found to be most predictive of early resorption (p<.05).

CONCLUSIONS

This is the first comprehensive imaging and clinical phenotypic prospective study, to our knowledge, that has identified distinct determinants for early LDH resorption. Early resorption can occur in 24.7% of LDH patients. We developed a prediction model for early resorption which demonstrated great overall performance according to pretreatment measures of herniation size, L4 posterior body height, and sacral slope. A risk profile is proposed which may aid clinical decision-making and managing patient expectations.

Resorption of Lumbar Disk Herniation: Mechanisms, Clinical Predictors, and Future Directions

INTRODUCTION

Resorption after lumbar disk herniation is a common yet unpredictable finding. It is hypothesized that nearly 70% of lumbar herniated nucleus pulposus (HNP) undergo the resorption to a significant degree after acute herniation, which has led to nonoperative management before surgical planning.

METHODS

This narrative review on the literature from 4 databases (MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Scopus, and Cochrane) examines historical and recent advancements related to disk resorption. Studies were appraised for their description of the predictive factor (e.g., imaging or morphologic factors), pathophysiology, and treatment recommendations.

OBSERVATIONS

We reviewed 68 articles considering the possibility of resorption of lumbar HNP. Recent literature has proposed various mechanisms (inflammation and neovascularization, dehydration, and mechanical traction) of lumbar disk resorption; however, consensus has yet to be established. Current factors that increase the likelihood of resorption include the initial size of the herniation, sequestration, percentage of rim enhancement on initial gadolinium-based magnetic resonance imaging (MRI), composition of inflammatory mediators, and involvement of the posterior longitudinal ligament.

CONCLUSION

Heterogeneity in imaging and morphologic factors has led to uncertainty in the identification of which lumbar herniations will resorb. Current factors that increase the likelihood of disk resorption include the initial size of the herniation, sequestration, percentage of rim enhancement on initial MRI, composition of cellular and inflammatory mediators present, and involvement of the posterior longitudinal ligament. This review article highlights the role of disk resorption after herniation without surgical intervention and questions the role of traditional noninflammatory medications after acute herniation. Further research is warranted to refine the ideal patient profile for disk resorption to ultimately avoid unnecessary treatment, thus individualizing patient care.

[Research progress of resorption of lumbar disc herniation]

OBJECTIVE

To summarize the research progress of resorption of lumbar disc herniation (RLDH).

METHODS

The literature on RLDH at home and abroad in recent years was reviewed to summarize its influencing factors, pathogenesis, imaging findings, and predictive effect, as well as its influence on the treatment selection of lumbar disc herniation (LDH).

RESULTS

The main mechanism of RLDH is the combined effect of inflammatory response and neovascularization. Age, smoking, body mass index, and clinical manifestations are the influencing factors. Studies have shown that the annular enhancement around the nucleus pulposus on enhanced MRI images is the characteristic imaging manifestation of RLDH, which is a predictor of whether RLDH occurs. In the treatment of LDH, cyclooxygenase 2 inhibitors may have a negative impact on RLDH.

CONCLUSION

The occurrence of RLDH suggests that strict conservative treatment is the first choice for LDH treatment, but surgery is still an important treatment method when the patient's symptoms and imaging symptoms don't significantly improved after conservative treatment.

Characteristics and mechanisms of resorption in lumbar disc herniation

Lumbar disc herniation (LDH) can be spontaneously absorbed without surgical treatment. However, the pathogenesis and physiological indications for predicting protrusion reabsorption are still unclear, which prevents clinicians from preferentially choosing conservative treatment options for LDH patients with reabsorption effects. The purpose of this review was to summarize previous reports on LDH reabsorption and to discuss the clinical and imaging features that favor natural absorption. We highlighted the biological mechanisms involved in the phenomenon of LDH reabsorption, including macrophage infiltration, inflammatory responses, matrix remodeling, and neovascularization. In addition, we summarized and discussed potential clinical treatments for promoting reabsorption. Current evidence suggests that macrophage regulation of inflammatory mediators, matrix metalloproteinases, and specific cytokines in intervertebral disc is essential for the spontaneous reabsorption of LDH.

Comparison of Percutaneous Endoscopic Interlaminar Discectomy and Open Fenestration Discectomy for Single-Segment Huge Lumbar Disc Herniation: A Two-year Follow-up Retrospective Study

Purpose

Both percutaneous endoscopic lumbar discectomy (PELD) and open fenestration discectomy (OFD) are effective and safe surgical procedures for the treatment of LDH. The purpose of this retrospective study was to compare the surgical outcomes of percutaneous endoscopic interlaminar discectomy (PEID) and OFD for single-segment huge lumbar disc herniation (HLDH).

Patients and Methods

We retrospectively analyzed 91 patients diagnosed with single-segment HLDH and treated with OFD or PEID. Visual analog scale (VAS), modified Japanese orthopedic association (mJOA) and Oswestry disability index (ODI) were used to assess clinical outcomes at preoperation and postoperatively at 3, 6, 12, and 24months. Modified Macnab criteria were applied to evaluate clinically satisfaction at the final follow-up.

Results

In both groups, the VAS and ODI scores at 3, 6, 12, and 24months postoperatively showed a significant decrease and the mJOA score at 3, 6, 12, and 24months postoperatively was significantly increased compared to preoperative results (P<0.001). According to Macnab criteria at the final follow-up, the overall clinically satisfactory rate was 86.67% in the OFD group and 86.96% in the PEID group. There were no significant differences in VAS, ODI, and mJOA scores between the two groups at preoperation and postoperative 3, 6, 12, and 24months, respectively. In the PEID group, the length of hospitalization and the length of incision were significantly shorter than that in the OFD group (P<0.0001). However, there was no significant difference in operative time between groups (P=0.81).

Conclusion

Collectively, postoperative clinical results were equally favorable for both procedures, with no statistically significant difference between PEID and OFD at the two-year of follow-up. No serious complication was observed in two groups. Compared with the traditional surgery, PEID has the following benefits: less trauma, less bleeding, speedy recovery, and shorter hospitalization. Therefore, PEID may be a promising alternative to traditional surgery.

Current Management of Cervical Spondylotic Myelopathy

Cervical spondylotic myelopathy (CSM) develops insidiously as degenerative changes of the cervical spine impact the spinal cord. Unfortunately, CSM is a form of spinal cord injury in older patients that often experiences delayed treatment. This summary evaluates the pathophysiology, natural history, diagnosis, and current management of CSM. Frequently, patients do not appreciate or correlate their symptomatology with cervical spine disease, and those with radiographic findings may be clinically asymptomatic. Providers should remember the classic symptoms of CSM-poor hand dexterity, new unsteady gait patterns, new onset and progressive difficulty with motor skills. An magnetic resonance imaging is required in patients with suspected CSM, but computerized tomography myelography is an alternative in patients with implants as contraindications to magnetic resonance imaging. The management of those with CSM has continued to be a controversial topic. In general, patients with incidental findings of cervical cord compression that are asymptomatic can be managed conservatively. Those with daily moderate-severe disease that significantly affects activities of daily living should be treated operatively.

Acupuncture in the Treatment of Sequestered Intervertebral Disk Herniation

Objective: Most patients with sequestered intervertebral disk herniation (IVDH) are subjected to neurosurgery. This study was designed to demonstrate that acupuncture can be an effective treatment modality for patients with herniated disks unless the disease is complicated. Materials and Methods: Three patients with IVDH received 2-3 courses of acupuncture treatment (12 sessions each) combined with pharmacopuncture with chondroprotector. Visual analogue scale (VAS) for pain and magnetic resonance imaging findings were used to test the effectiveness of the treatment. Results: Decrease in pain severity has been observed from 7-8 points to 3-4 points in VAS after the first course of treatment. Complete resorption of hernia sequesters in 4-5 months after the treatment has been started. Conclusions: Acupuncture is an effective alternative for patients with IVDH unless surgery is indicated. Acupuncture treatment results in resorption of hernia sequester and improves pain syndrome.

Spontaneous regression of herniated cervical disc: A case report and literature review

Background

We have reviewed 75 cases plus our own single instance of spontaneous regression of herniated cervical discs.

Methods

We searched PubMed and EMBASE databases (until September 2020) utilizing the following keywords; "spontaneous regression," "herniated cervical disc," and "Magnetic Resonance Imaging (MRI) studies."

Results

In the literature, we found 75 cases of herniated cervical discs which spontaneously regressed; to this, we added our case. Patients averaged 40.95 years of age. Discs were paracentral or foraminal in 84% of the cases, with most occurring at the C5-C6 (51%) and C6-C7 (36%) levels. Symptoms included neck pain/radiculopathy (91%) or myelopathy (9%). The average interval between initial presentation and spontaneous regression of herniated discs on MRI was 9.15 months. Interestingly, on MRI, extruded/sequestrated discs were more likely to undergo spontaneous regression versus protruding discs.

Conclusion

Successive MRI studies documented the spontaneous regression of herniated cervical discs over an average of 9.15 months. Although this may prompt greater consideration for conservative treatment in younger patients without neurologic deficits, those with deficits should be considered for surgery.

Platelet-Rich Plasma and Epidural Platelet Lysate: Novel Treatment for Lumbar Disk Herniation

Lumbar herniated disks present a common cause of significant axial low back and radiating leg pain. This situation poses a risk for potentially permanent neurologic compromise, including numbness, weakness, and bowel and bladder dysfunction. Traditional treatment strategies such as medications, epidural steroids, and surgery all carry potential risk for iatrogenic sequelae. Platelet-rich plasma can be processed to isolate and concentrate the growth factors contained in platelet α granules. This solution is then referred to as platelet lysate. Lumbar injection of platelet-rich plasma along with epidural injection of platelet lysate is a novel therapeutic option that can initiate or expedite the resorption of herniated lumbar disk material, which can facilitate the decompression of the affected spinal structures. This process is thought to occur through a complex interplay of cytokines and growth factors that facilitate neovascularization along with macrophage-induced phagocytosis of the disk material. In the present report, we describe 2 patients with symptomatic herniated disks who were successfully treated with epidural injection of growth factors derived from concentrated platelet lysate.

Non-surgical treatment with XSHHD for ruptured lumbar disc herniation: a 3-year prospective observational study

Background

Lumbar disc herniation (LDH) is mainly caused by annular fiber disruption with a discrete leakage of nucleus pulposus pressing on a nerve, resulting in back pain and radiating pain. Most patients with LDH can be treated conservatively, but there are many different conservative treatments. Furthermore, most previous studies did not evaluate the long-term efficacy of these treatments and the prognosis. Therefore, an effective and safe therapeutic strategy is lacking for patients with LDH. In this study, we evaluated Xiao Sui Hua He decoction (XSHHD) in the treatment of LDH.

Methods

This was a rigorous prospective observational 3-year follow-up study. We recruited 69 participants with ruptured lumbar disc herniation (RLDH) between February 2014 and February 2016. Patients took XSHHD orally twice a day for 6 months. The primary outcome measurements were visual analogue scale (VAS) pain score, Oswestry disability index (ODI) and straight leg raising test (SLRT). The secondary outcome measurements was nucleus pulposus protrusion volume on magnetic resonance imaging (MRI). Clinical outcomes were measured at baseline (Visit 1), and at 3, 6, 12, and 36 months (Visit 2, 3, 4, and 5, respectively)..

Results

Sixty-three patients were followed-up for 3 years after treatment. SLRT and ODI after non-surgical treatment improved significantly compared with baseline (P < .001). There were no statistically significant differences at 6 months vs 36 months for SLRT and ODI. VAS scores (leg, back) after 3 years of treatment were statistically significantly different compared with baseline (P < .001; Z = − 6.93, − 6.637). The baseline protrusion volume was 2018.61 ± 601.16 mm³, and the volume decreased significantly to 996.51 ± 387.42 mm3 at 36 months (t = 12.863; P < .001). The volume of protrusion resorption rate (VPRR) at 36 months was 47.24 ± 23.99%, with significant resorption in 23 cases, partial resorption in 23 cases, no resorption in 15 cases, and increased volume in 2 cases.

Conclusions

This study showed that non-surgical treatment with XSHHD was effective, and the study clarified the natural outcomes in LDH.

Resorption of upwardly displaced lumbar disk herniation after nonsurgical treatment: A case report

BACKGROUND

The spontaneous resorption of lumbar disk herniations (LDHs) has been widely reported. However, the majority of these reports analyze the resorption of LDHs that were displaced backwards or downwards. There have been few reports on the spontaneous resorption of upwardly displaced L4/5 LDH that has caused femoral nerve symptoms.

CASE SUMMARY

A 55-year-old woman presented to our hospital with acute pain in her left leg. She had been suffering from recurrent lower back pain for approximately 1 year and began to feel pain accompanied with numbness at the anterior aspect of her left leg 7 d previously. On examination, a typical L4 nerve stimulation was noted. An upwardly displaced LDH at the L4/5 level was revealed by magnetic resonance imaging. The patient attained complete relief of her symptoms after 10 wk of nonsurgical treatment and the upwardly displaced herniation almost entirely disappeared. There was no recurrence during a follow-up of 2 years.

CONCLUSION

Clinicians should be aware that the nerves disturbed by LDHs vary according to the direction of the herniations and the probable resorption of upwardly displaced LDHs should be considered before making a decision on surgery.

The Management of Symptomatic Lumbar Disc Herniation in Pregnancy: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

Lumbar disc herniation (LDH) has been reported to affect 1 in 10 000 pregnant women. There is limited evidence available regarding the optimal management of LDH in pregnant patients. We aimed to review the current evidence for the management of symptomatic LDH in pregnancy through critical appraisal and analysis of the available literature.

METHODS

Searches were conducted in Medline, Embase, PubMed, Science Direct, and The Cochrane Library from inception using predetermined search terms. All peer-reviewed studies of pregnant women with symptomatic LDH were included. The quality of eligible articles was assessed and extracted data and characteristics were pooled for analysis. References cited by studies were screened to identify other relevant publications.

RESULTS

Thirty studies involving 52 patients were identified. Compared to surgically managed patients, conservatively managed patients had a higher full recovery rate (61.54% vs 56.41%) and reported a lower rate of persistent symptoms (30.77% vs 38.54%). Compared to patients who were treated surgically for cauda equina syndrome, patients treated surgically for sciatica had a higher full recovery rate (80.95% vs 27.78%) and reported a lower rate of persistent symptoms (14.29% vs 66.67%).

CONCLUSION

There is limited evidence to guide the management of pregnant patients with LDH. Despite a suggestion toward improved outcomes with conservative management, the presence of selection bias and the overall poor quality of current research precludes reliable conclusions from being drawn. Decision making for this patient group should be undertaken within a multidisciplinary setting.

Are There Any Risk Factors Associated with the Presence of Cauda Equina Syndrome in Symptomatic Lumbar Disk Herniation?

OBJECTIVE

Risk factors for developing cauda equina syndrome (CES) caused by lumbar disk herniation (LDH) remain controversial and have not been established yet. The aim of the study was to investigate whether there is a relationship among age, sex, body mass index (BMI), or the degree of spinal canal compromise and the presence of CES in patients undergoing lumbar microdiskectomy.

METHODS

Between 2015 and 2019, 506 patients who had an operation for LDH compressing the dural sac were prospectively identified. The "prolapse-to-canal ratio" (PCR) was calculated as a proportion of the cross-sectional area of the disk prolapse compared with the total cross-sectional area of the spinal canal.

RESULTS

In total, 35 CES (6.9%) patients were identified. Multivariate logistic regression, adjusted for age, gender, BMI, and PCR, shows that only PCR was associated with the presence of CES (P < 0.001, area under the curve 0.7431). BMI was not associated with an increased risk of CES.

CONCLUSIONS

This study demonstrates a significant correlation between the size of LDH relative to size of the spinal canal and the presence of CES. A finding of LDH causing >60% obstruction of the spinal canal should be considered a red flag, and such patients need to be watched more closely.

Polarization of Macrophages in Epidural Inflammation Induced by Canine Intervertebral Disc Herniation

Introduction: Canine interverterbral disc (IVD), although physiologically acellular, displays an inflammatory cell population consisting almost exclusively of macrophages (Mϕ) when acutely herniated. Mϕ encompass a heterogenous cell population, roughly divided into classically (M1) or alternatively activated (M2)Mϕ. Polarization into M1 Mϕ leads to strong antimicrobial activity and pro-inflammatory response. In contrast, M2Mϕ exibit anti-inflammatory function and regulate wound healing. The purpose of this study was to characterize the phenotype of the Mϕ population present in naturally occurring IVD herniation.

Materials and Methods: IVD material of dogs with IVD disease was collected during standard decompressive surgery. A negative control consisting of IVD material of dogs without IVD degeneration and a positive control consisting of canine liver and lymph node samples were also included. All samples were embedded in OCT and shock frozen. Eight micrometer cryostat sections were prepared, air dried and immunostained without prefixation or permeabilization. CD14 was used as marker Mϕ, MHCII for M1Mϕ and CD206 for M2Mϕ.

Results: Fifteen samples of dogs with IVD herniation, 10 negative, and 5 positive control samples were obtained. No positive cell was found in the negative control group. The positive control group displayed several MHCII and CD206 positive cells, all of them being simultaneously positive to CD14. All herniated samples displayed a mixed population of M1Mϕ and M2Mϕ, and some sparse Mϕ displaying markers for both M1 and M2Mϕ simultaneously.

Conclusion: The mixed phenotype encountered shows the plasticity and dynamism of Mϕ and evidences the chronic component of IVD disease despite its acute clinical presentation.

The Immune Privilege of the Intervertebral Disc: Implications for Intervertebral Disc Degeneration Treatment

The intervertebral disc (IVD) is the largest avascular organ of the body. It is composed of three parts: the nucleus pulposus (NP), the annulus fibrosus (AF) and the cartilaginous endplate (CEP). The central NP is surrounded by the AF and sandwiched by the two CEPs ever since its formation. This unique structure isolates the NP from the immune system of the host. Additionally, molecular factors expressed in IVD have been shown inhibitive effect on immune cells and cytokines infiltration. Therefore, the IVD has been identified as an immune privilege organ. The steady state of immune privilege is fundamental to the homeostasis of the IVD. The AF and the CEP, along with the immunosuppressive molecular factors are defined as the blood-NP barrier (BNB), which establishes a strong barrier to isolate the NP from the host immune system. When the BNB is damaged, the auto-immune response of the NP occurs with various downstream cascade reactions. This effect plays an important role in the whole process of IVD degeneration and related complications, such as herniation, sciatica and spontaneous herniated NP regression. Taken together, an enhanced understanding of the immune privilege of the IVD could provide new targets for the treatment of symptomatic IVD disease. However, the underlying mechanism above is still not fully clarified. Accordingly, the current study will extensively review and discuss studies regarding the immune privilege of the IVD.

Spontaneous regression of calcified thoracic herniations: Can Hounsfield-units radiodensity have a predictive value?

INTRODUCTION

Spontaneous regressions of calcified thoracic disc herniations (TDH) have been rarely described. Since now, no previous papers hypothesized that radiological factors could be able to predict the evolution of the herniation. This study shows that the radiodensity of the herniated material in herniations with spontaneous resolution might differ from that of operated herniations.

METHODS

This is a retrospective study. A cohort of patients that underwent surgical removal of a calcified thoracic disc herniation has been compared to two cases conservatively treated and a case with spontaneous regression. CT scans were evaluated to compute the average radiodensity [in Hounsfield units (HU)] of the calcified components of the herniations. All the slices of the CT scans involving the calcification were evaluated in their axial images and in their coronal and sagittal reformations. Comparison of the slices radiodensity (spontaneously resolved versus surgically treated) was performed with the unpaired Student's t test.

RESULTS

The mean density of calcification in the case with spontaneous regression was found to be 454 HU. In the control group of surgical cases observed, and the conservatively treated cases, the mean HU density showed higher values (respectively, 827 and 853 HU) (p < 0.01).

CONCLUSION

Qualitative differences between calcified TDH that resolve spontaneously or need surgical treatment might be shown by differences of radiodensity. This comparative study, in spite of the limitations due to small numbers, provides a new insight in the interpretation of the phenomenon of spontaneous resolution of calcified TDH. These slides can be retrieved under Electronic Supplementary Material.

Effects of swimming on pain and inflammatory factors in rats with lumbar disc herniation

The aim of the present study was to identify the effect of swimming on nerve root pain in rats with lumbar disc herniation (LDH). A total of 72 male Sprague Dawley rats (215±15 g) were randomly divided into three groups (n=24/group): The sham operation, model and exercise intervention groups, with the latter undergoing 4 weeks of swimming training. On days 0, 7, 14 and 28 following surgery, the changes in the post-limb mechanical claw threshold, the phospholipase A2 (PLA2), interleukin (IL)-6 and tumor necrosis factor (TNF)-α mRNA expression levels, the secretory PLA2 (sPLA2) expression, the IL-6 and TNF-α content, the nuclear factor (NF)-κBp65 protein expression level in the nucleus pulposus, and the apoptotic rate of the nucleus pulposus cells were detected. The results demonstrated that, in the model group, the threshold of hind paw withdrawal was decreased, and that the sPLA2 expression, IL-6 and TNF-α content, PLA2, IL-6 and TNF-α mRNA and NF-κBp65 protein expression levels in the nucleus pulposus were increased. The apoptotic rate of the nucleus pulposus cells was increased from day 7 following surgery, as compared with the sham operation group. In the exercise intervention group, the hind paw withdrawal threshold increased and the TNF-α and IL-6 content, sPLA2 expression and PLA2, IL-6 and TNF-α mRNA and NF-κBp65 protein expression levels were decreased from day 14 following surgery, and the apoptotic nucleus pulposus cells were decreased from day 7 following surgery, as compared with the model group. Collectively, the present data suggest that swimming can significantly reduce nerve root pain and inhibit inflammatory reaction in LDH, which can have positive effects on the treatment of LDH.

Spontaneous regression of cervical discs: Retrospective analysis of 14 cases

Cervical disc herniation is a condition which arises from compression of cervical spinal nerve root by the degenerated disc and vast majority of the patients are aged between 30 and 40 years. Spontaneous regression of cervical disc was first reported by Kriegerand Maniker in 1992. Our study is the second large series in literature. Besides, 4 patients are the first who were shown to have resorption in C 4-5.The records of patients diagnosed with cervical disc herniation who applied to the Spine Polyclinic between 2014 and 2018 were reviewed retrospectively. The files of the patients who were recommended surgery with the diagnosis of cervical disc herniation were examined. Patients who did not accept surgery on their own initiative, but who attended our outpatient clinic for a check-up were included in the study.Of a total of 14 patients, 28.57% (n = 4) were male and 71.43% (n = 10) were female. Mean age of the patients was 40.79 (range 25-60).The results of the study indicate that likelihood of spontaneous regression is higher in para-central or foraminal disc compared to central disc hernias. Although there are a limited number of case reports in the literature, conservative treatment seems to be a good option in patients without neurological deficits, with foraminal disc hernias and not requiring emergency surgery.

Clinical Efficacy and Safety of Trans-Sacral Epiduroscopic Laser Decompression Compared to Percutaneous Epidural Neuroplasty

Percutaneous epidural neuroplasty (PEN) is an effective and safe procedure for herniated lumbar disc (HLD). Although PEN has an advantage of adhesiolysis, this procedure cannot decompress the protruded disc. Recently, trans-sacral epiduroscopic laser decompression (SELD) for HLD has been introduced as a promising alternative methodology. This study evaluated the clinical efficacy and safety of SELD compared to PEN, as well as the change in protruded disc volume after SELD through pre- and postoperative magnetic resonance imaging (MRI), in patients with HLD. Thirty consecutive patients underwent SELD (SELD group), and 45 patients underwent PEN (PEN group). The Visual Analog Scale (VAS) for leg pain; Oswestry Disability Index (ODI); 12-Item Short-Form Health Survey (SF-12); preoperative and postoperative 4-, 12-, and 24-week Macnab criteria; and preoperative and 24-week postoperative lumbar spinal MRIs after SELD were obtained. There was no significant difference in age, sex, duration of symptoms, and the distributions of disc level between the two groups (all P > 0.05). Between the SELD and PEN groups, preoperative VAS, ODI, and SF-12 scores had no significant differences. However, the VAS, ODI, and SF-12 scores improved significantly after the procedures by postoperative week 24 in each group (all P < 0.05). Furthermore, improvements of VAS, ODI, SF-12, and success rate of Macnab criteria in the SELD group were better than those in the PEN group (all P < 0.05). The protruded disc volume after SELD decreased significantly (P=0.034). All clinical and functional outcomes of patients undergoing SELD and PEN for HLD improved following the procedures. Notably, SELD was superior to PEN regarding the degree of improvement in clinical and functional outcomes. Therefore, we suggest that SELD can be used as an effective alternative to PEN to provide improved clinical and functional outcomes in patients with HLD.

Spontaneous Resorption of Herniated Lumbar Disk: Observational Retrospective Study in 9 Patients

BACKGROUND

Spontaneous resorption of herniated lumbar disk was explained in the literature by different mechanisms, and multiple predictive factors for resorption were reported in numerous studies. The purpose of this study was to evaluate the phenomena of spontaneous resorption of herniated lumbar disk without surgery (mechanisms, predictive factors, expected time for resorption, and proper time for conservative treatment).

METHODS

This retrospective clinical case series included 9 patients with herniated lumbar disk on initial magnetic resonance imaging (MRI). The mean age was 39 ± 6.3 years, and the male to female ratio was 2:1. All patients presented with back pain and sciatica without motor deficit. All patients refused surgical intervention; therefore, they were treated conservatively. Patients were followed-up clinically and radiologically (MRI) in the outpatient clinic on regular visits (for 18 months).

RESULTS

Spontaneous resorption of herniated disk was found in all patients in a mean time of 8.7 ± 3.2 months. All patients recovered clinically in a mean time of 5.7 ± 1.6 weeks by conservative treatment. Large and/or sequestrated disks were associated with rapid resorption. Early recovery patients showed early spontaneous resorption of the disk.

CONCLUSIONS

Spontaneous resorption of herniated lumbar disk can occur by different mechanisms (retraction, dehydration, and inflammatory mediated mechanism). Large and/or sequestrated disks are essential predictive factors for rapid spontaneous resorption. Furthermore, early clinical recovery is usually associated with quick resorption of the herniated disk.

ABCs of the degenerative spine

Degenerative changes in the spine have high medical and socioeconomic significance. Imaging of the degenerative spine is a frequent challenge in radiology. The pathogenesis of this degenerative process represents a biomechanically related continuum of alterations, which can be identified with different imaging modalities. The aim of this article is to review radiological findings involving the intervertebral discs, end plates, bone marrow changes, facet joints and the spinal canal in relation to the pathogenesis of degenerative changes in the spine. Findings are described in association with the clinical symptoms they may cause, with a brief review of the possible treatment options. The article provides an illustrated review on the topic for radiology residents.

TEACHING POINTS

• The adjacent vertebrae, intervertebral disc, ligaments and facet joints constitute a spinal unit. • Degenerative change is a response to insults, such as mechanical or metabolic injury. • Spine degeneration is a biomechanically related continuum of alterations evolving over time.

Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level

Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain due to disc herniation caudally immigrating at L4-5 level three years ago. He refused the surgical intervention that was offered and was treated conservatively at that time. He had no neurological deficit and a history of spontaneous regression of the extruded lumbar disc; so, a conservative therapy, including bed rest, physical therapy, nonsteroidal anti-inflammatory drugs, and analgesics, was advised. In conclusion, herniated lumbar disc fragments may regress spontaneously. Reports are prone to advise conservative treatment for extruded or sequestrated lumbar disc herniations. However, these patients should be followed up closely; new herniation at adjacent/different level may occur. Furthermore, it is important to know which herniated disk should be removed and which should be treated conservatively, because disc herniation may cause serious complications as muscle weakness and cauda equine syndrome.

Spontaneous regression of herniated lumbar discs: Report of one illustrative case and review of the literature

Lumbar disc herniation (LDH) is a common disease that induces back pain and radicular pain. The most efficient method for the treatment of lumbar disc herniation is still controversial. Spontaneous regression of LDH has been recognized with the advancement of radiological diagnostic tools and can explain the reason of spontaneous relief of symptoms without treatment. The proposed hypotheses are; dehydration, retraction of the disc to the hernia in the annulus fibrosis, enzymatic catabolism and phagocytosis. In this study, the case of a patient with huge lumbar disc hernia regressing by itself has been presented and the potential mechanisms of disc regression have been discussed.

Traditional Chinese medicine treatment for ruptured lumbar disc herniation: clinical observations in 102 cases

OBJECTIVE

To explore the therapeutic effects of a traditional Chinese medicine (TCM) regimen on patients with ruptured lumbar disc herniation, including assessing its effects on prognosis and protrusion size.

METHODS

From June 2008 to December 2011, 102 patients with ruptured lumbar disc herniation who chose conservative treatment with TCM as their first choice were followed up for 2 years to assess their final surgical rate, improvement according to Japanese Orthopaedic Association (JOA) scores, and to calculate the volume and rate of resorption of their protrusions by magnetic resonance imaging (MRI).

RESULTS

(i) Eighty-three of the 102 patients (81.37%) experienced partial or complete relief; the remaining 19 (18.63%) eventually needed surgery. (ii) In the 83 patents who underwent conservative treatment, rates of excellent JOA scores at 3 months, 6 months, 1 year and 2 years were 79.52%, 81.93%, 81.93% and 83.13% respectively; differences between these and pretreatment scores are all statistically significant (P < 0.01). (iii) The volume of protrusion in the patients who chose conservative treatment decreased from 1433.89 ± 525.49 mm(3) (mean ± SD) to 1002.01 ± 592.95 mm(3), which is statistically significant (t = 6.854, P < 0.01). The average resorption rate was 27.25% ± 32.97%; in 20 patients (24.10%) the resorption rate was >50%. The remaining 63 patients had no obvious resorption; their excellent rate was 77.77%. The difference in rate of achieving an excellent outcome differed significantly between those who did and did not have resorption of their protrusions (P = 0.018).

CONCLUSION

Conservative treatment with a TCM regimen is effective for ruptured lumbar disc herniation and can promote resorption of the protrusion; however, patients who develop specific indications for surgery during such treatment should undergo surgery in a timely manner.

Spontaneous remission of a big subligamentous extruded disc herniation: case report and review of the literature

Spontaneous Regression of a Big Subligamentous Extruded Disc Herniation: Case Report And Review of The Literature The most efficient method for the treatment of lumbar disc herniation is still controversial. The most important aspect is the application of the suitable conservative or surgical treatment to the right patient at the right time. In lumbar disc herniation patients, one must not precipitate except for cases that require surgical indications as in cauda equina syndrome, evolutive motor deficit and persistence of pain in spite of the narcotics. However, the spontaneous regression mechanism has not been completely determined yet. The proposed hypotheses are; dehydration, retraction of the disc to the hernia in the annulus fibrosis, enzymatic catabolism and phagocytosis. In this study, the case of a patient with huge lumbar disc hernia regressing by itself has been presented and the potential mechanisms of disc regression have been discussed.

Migratory intradural disk herniation and a strategy for intraoperative localization

Study Design Case report. Objective Describe a case of intradural disk herniation and a method for intraoperative localization. Methods Intradural disk herniations are uncommon but well described. The diagnosis of these lesions is often difficult, and sometimes they may be diagnosed only through an intradural exploration after an expected disk fragment cannot be located. We report the case of an intradural disk herniation with an additional diagnostic difficulty-a migrated intradural disk. Results We present the first intraoperative imaging evidence of disk migration and propose a strategy to locate intradural disk fragments prior to durotomy. Conclusion Intradural disk herniations should be suspected when intraoperative findings are not congruent with imaging findings. An intraoperative myelogram may be helpful.

Spontaneous regression of cervical disc herniation: a case report

Spontaneous regression of cervical disc herniation is a rare, and such reports are few. A 39 year-old woman complained of severe neck pain associated with tingling and numbness of right upper extremity. The MRI of the cervical spine revealed a posterior disc extrusion at the C4-C5 level in the right para-central location. The patient was treated with conservative management without any surgical treatment. The patient's symptoms were significant improvement. After two years later, we performed follow-up cervical MRI that revealed significant spontaneous regression of the C4-C5 intervertebral disc extrusion.

Spontaneous regression of sequestrated lumbar disc herniations: Literature review

Lumbar disc herniations (LDH) may regress with conservative management; however, this phenomenon is poorly understood for the sequestrated subtype of LDH. We present one of the first comprehensive literature reviews specifically addressing the spontaneous regression of sequestrated intervertebral discs. We reviewed all publications with lumbar disc herniations, sequestrated subtype. Our results were then narrowed to patients who experienced spontaneous regression of the sequestration. Based on our literature review of 53 cases, patients with sequestrated lumbar disc herniations experienced symptomatic resolution in a mean of 1.33±1.34 months and radiographic resolution in 9.27±13.32 months. Symptomatic patients with sequestrated discs present similarly to those with other types of lumbar disc herniations. Sequestrations may have the highest likelihood to radiographically regress in the shortest time frame in comparison to the remaining subtypes of LDH. The most likely mechanism for regression is an inflammatory response elicited against the free fragment. Patients with disc sequestrations may be managed conservatively, in the absence of intractable pain, inability to walk, weakness or symptoms suggestive of cauda equina syndrome.

A Rare Case of Near Complete Regression of a Large Cervical Disc Herniation without Any Intervention Demonstrated on MRI

There are very few reported cases of regression of large cervical disc herniation without any intervention—the so-called spontaneous regression, demonstrated using MRI. We report a rare and interesting case of MRI that demonstrated near complete regression of a large herniated cervical intervertebral disc, without any surgical treatment.

Clinical and pathological analysis of epidural inflammation in intervertebral disk extrusion in dogs

BACKGROUND

Little is known about the pathologic changes in the epidural space after intervertebral disk (IVD) extrusion in the dog.

OBJECTIVES

To analyze the pathology of the epidural inflammatory response, and to search for correlations between this process and clinical findings.

METHODS

Clinical data from 105 chondrodystrophic (CD) and nonchondrodystrophic (NCD) dogs with IVD extrusion were recorded. Epidural material from these dogs was examined histopathologically and immunohistochemically. Using statistical analysis, we searched for correlations between severity of epidural inflammation and various clinical and pathologic variables.

RESULTS

Most dogs exhibited an epidural inflammatory response, ranging from acute invasion of neutrophils to formation of chronic granulation tissue. The mononuclear inflammatory infiltrates consisted mostly of monocytes and macrophages and only few T and B cells. Surprisingly, chronic inflammatory patterns also were found in animals with an acute clinical history. Severity of the epidural inflammation correlated with degree of the epidural hemorrhage and nucleus pulposus calcification (P = .003 and .040), but not with age, chondrodystrophic phenotype, neurologic grade, back pain, pretreatment, or duration. The degree of inflammation was statistically (P = .021) inversely correlated with the ability to regain ambulation.

CONCLUSION AND CLINICAL IMPORTANCE

Epidural inflammation occurs in the majority of dogs with IVD extrusion and may develop long before the onset of clinical signs. Presence of calcified IVD material and hemorrhage in the epidural space may be the triggers of this lesion rather than an adaptive immune response to the nucleus pulposus as suggested in previous studies. Because epidural inflammation may affect outcome, further research is warranted.