Radiculopathy associated with disc herniation

Return to sports following discectomy: does a consensus exist?

INTRODUCTION

In the USA, lumbar discectomy is one of the most commonly performed spinal procedures. As certain sports are considered to be major risk factors for disc herniation, the question remains as to when highly active patients should return to their previous level of activity. This study aimed to analyze spine surgeons' opinions on when patients may return to activities following discectomy as well as their underlying rationale for their decision.

METHODS

A questionnaire was designed by five different fellowship-trained spine surgeons for the 168 members of the Spine Society of Australia. Questions on the surgeons experience, decision making, preferred surgical technique, the postoperative rehabilitation and the response to patient expectations were included.

RESULTS

In total, 83.9% of surgeons discuss the postoperative level of activity with their patients. Sport is considered as an important contributor for good functional outcome by 71.0% of surgeons. Surgeons recommend avoiding, often permanently, weightlifting (35.7%) of the time, rugby (21.4%), horseback riding (17.9%) as well as martial arts (14.3%) postoperatively even with previous training. The return to high levels of activity is considered as a major risk factor for disc herniation recurrence by 25.8% of surgeons. Return to high level of activity is typically recommended after 3 months by 48.4% of surgeons.

CONCLUSION

So far no consensus on the rehabilitation protocol and return to level of activity exists. Recommendations depend on personal experience as well as the individuals' training, and typically, a period of avoidance of sport for up to 3 months is recommended.

LEVEL OF EVIDENCE

Level III, therapeutic and prognostic study.

Revalidating Pfirrmann's Magnetic Resonance Image-Based Grading of Lumbar Nerve Root Compromise by Calculating Reliability among Orthopaedic Residents

Background

Intervertebral disc herniations lead to subsequent compromise of the nerve root. The root can either have a mere contact with the disc material or be pushed aside or compressed. This was earlier graded by Pfirrmann and colleagues. We intend to revalidate this grading system by performing a reliability analysis among orthopaedic residents.

Methods

Fifty axial cut magnetic resonance (MR) images of the affected lumbar disc level that belonged to different patients (age, 37.8 ± 10.4 years; 33 males and 17 females) were chosen and given to five orthopaedic residents for grading according to the Pfirrmann's MR image-based grading of lumbar nerve root compromise. Responses were received in the form of categorical variables and reliability was assessed.

Results

On doing percentage statistics, we found that 14 images had 100% agreement, 22 had 80% agreement and 14 had 60% agreement. We inferred an overall agreement of 80% ± 15.1%. In addition, interrater reliability was determined by calculating the Fleiss' kappa, which was found to be 0.521, signifying moderate agreement. Intrarater reliability was determined by calculating Cohen's kappa, which was found to be 0.696, signifying substantial agreement.

Conclusions

Our residents took only a short time to learn and reproduce this grading system as ratings that proved to be moderately reliable. Even though the value of kappa was slightly lower, reliability was similar to that of the original authors. We think that this grading system can be adopted in day-to-day practice by framing appropriate rules to interpret MR images where the nerve roots are not visible.

Treatment of lumbar degenerative disc disease-associated radicular pain with culture-expanded autologous mesenchymal stem cells: a pilot study on safety and efficacy

Background

Degenerative disc disease (DDD) is a common cause of lower back pain with radicular symptoms and has a significant socioeconomic impact given the associated disability. Limited effective conservative therapeutic options result in many turning to surgical alternatives for management, which vary in the rate of success and also carry an increased risk of morbidity and mortality associated with the procedures. Several animal based studies and a few human pilot studies have demonstrated safety and suggest efficacy in the treatment of DDD with mesenchymal stem cells (MSCs). The use of bone marrow-derived MSCs for the treatment of DDD is promising and in the present study we report on the safety and efficacy findings from a registry based proof of concept study using a percutaneous intradiscal injection of cultured MSCs for the management of DDD with associated radicular symptoms.

Methods

Thirty-three patients with lower back pain and disc degeneration with a posterior disc bulge diagnosed on magnetic resonance imaging (MRI) met the inclusion criteria and were treated with culture-expanded, autologous, bone marrow-derived MSCs. Prospective registry data was obtained at multiple time intervals up to 6 years post-treatment. Collected outcomes included numeric pain score (NPS), a modified single assessment numeric evaluation (SANE) rating, functional rating index (FRI), measurement of the intervertebral disc posterior dimension, and adverse events.

Results

Three patients reported pain related to procedure that resolved. There were no serious adverse events (i.e. death, infection, or tumor) associated with the procedure. NPS change scores relative to baseline were significant at 3, 36, 48, 60, and 72 months post-treatment. The average modified SANE ratings showed a mean improvement of 60% at 3 years post-treatment. FRI post-treatment change score averages exceeded the minimal clinically important difference at all time points except 12 months. Twenty of the patients treated underwent post-treatment MRI and 85% had a reduction in disc bulge size, with an average reduction size of 23% post-treatment.

Conclusions

Patients treated with autologous cultured MSCs for lower back pain with radicular symptoms in the setting of DDD reported minor adverse events and significant improvements in pain, function, and overall subjective improvement through 6 years of follow-up.

NCT03011398. A Clinical Registry of Orthobiologics Procedures. https://clinicaltrials.gov/ct2/show/NCT03011398?term=orthobiologics&rank=1

Changes in expression of mRNA for interleukin-8 and effects of interleukin-8 receptor inhibitor in the spinal dorsal horn in a rat model of lumbar disc herniation

STUDY DESIGN

Autologous nucleus pulposus obtained from coccygeal intervertebral discs was grafted on the proximal of L5 dorsal root ganglion. Pain behavior, mRNA expression of Interleukin-8 (IL-8), and immunohistochemical changes were assessed.

OBJECTIVE

The purpose of this study is to investigate temporal changes of IL-8 expression in the spinal cord and dorsal root ganglion and the pain-related behaviors with time course and to elucidate whether repertaxin (IL-8 receptor inhibitor) attenuates pain-related behaviors in a rat model of lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

Inflammatory mediators like cytokines and chemokines have been implicated in radicular pain because of disc herniation. IL-8, known as CXCL8, is a chemokine, which has been reported to be associated with painful degenerative disc disorders and chronic inflammatory pain states.

METHODS

Lumbar disc herniated rat model was made by implantation of the autologous nucleus pulposus, harvested from the coccygeal vertebra of each tail, on the left L5 nerve root just proximal to the dorsal root ganglion. Rats were tested for mechanical allodynia and thermal hyperalgesia at 2 days before surgery, and on days 1, 5, 10, 20, 30, 40, 50, and 60 postoperatively. Experimental group was intrathecally injected with the IL-8 receptor inhibitor at L5 level on postoperative day 10. Mechanical allodynia of the plantar surface of both hindpaw was tested on 30 minutes, 1, 3 hours, 1, 3, 5, and 10 days after administration. For the staining of astrocytes and microglia, immunohistochemical study was done 20 days after surgery.

RESULTS

Mechanical allodynia in ipsilateral hindpaw developed 1 day after surgery and lasted until 60 days and thermal withdrawal latency decreased significantly on the ipsilateral side 10 days after surgery and gradually increased through day 60. The IL-8 receptor inhibitor attenuated the mechanical allodynia caused by nucleus pulposus when it was administered on postoperative day 10 and reduced microglial activation and phosphorylated form of mitogen-activated protein kinase (pERK) expression in the spinal dorsal horn.

CONCLUSION

IL-8 might be a potential therapeutic target in chronic radicular neuropathic pain because of disc herniation, CXCL8 inhibitor could be one of its promising therapeutic agents.

Adalimumab for the Treatment of Refractory Sciatica Induced by Disc Prolapse

Ten patients with back pain and sciatica were selected according to certain inclusion criteria for a study to assess the efficacy of the Anti TNF agent Adalimumab in the treatment of refractory sciatica pain induced by a lumbar disc prolapse in patients who failed to improve following lumbar epidural steroid or disc surgery. Each was given a subcutaneous injection of 40mg Adalimumab repeated after two weeks. Patients were assessed regularly on weeks 0, 2, 4 and 8 employing the Visual Analogue Score (VAS) for leg pain and back pain and the Straight Leg Raising (SLR) test. The median improvement of the leg pain VAS was 55. Median improvements of back pain VAS was 37. Median improvement of the SLR was 45. The study demonstrated the beneficial effect of adalimumab therapy in reducing the back and leg pain associated with sciatica in this difficult to treat group of patients. The improvement of leg pain was more significant than that of back pain. The response was better in patients with symptoms of shorter duration and with less SLR restriction at base line.

Changes in spinal cord expression of fractalkine and its receptor in a rat model of disc herniation by autologous nucleus pulposus

STUDY DESIGN

Behavior, mRNA and immunohistochemical assessment of the expression of fractalkine (CX3CL1) and its receptor (CX3CR1) in a rat model of disc herniation by autologous nucleus pulposus (NP) implantation.

OBJECTIVE

To evaluate the changes in expression of fractalkine and its receptor in the spinal cord and their association with pain behavior in a rat model of disc herniation.

SUMMARY OF BACKGROUND DATA

Chemokines have recently been implicated in the pathophysiology of neuropathic pain. They mediate astrocytic migration and microglial proliferation, which are involved in the regulation of nociceptive transmission. Fractalkine is a chemokine, which participates in the mechanisms of neuropathic pain as a mediator of neuron-glia interactions.

METHODS

Sixty-six rats (NP-treated = 47, sham = 19) were implanted with autologous NP (approximately 3 mg) on the left L5 nerve root, just proximal to the dorsal root ganglion and tested for thermal hyperalgesia and mechanical allodynia before surgery and on days 1, 5, 10, 20, and 30 after surgery. The changes of expression of fractalkine and its receptor in the spinal cord were studied using real time PCR and immunohistochemistry.

RESULTS

Rats developed ipsilateral mechanical allodynia at day 1 and bilateral thermal hyperalgesia at day 5 after surgery, and these changes in sensitivity persisted throughout the observation period. The expression of mRNA for fractalkine in the spinal cord was increased by day 5 and remained upregulated for the duration of the experiment. The immunostaining for fractalkine increased in neurons and astrocytes and that for the fractalkine receptor increased in microglia in the dorsal horn ipsilateral to the disc herniation.

CONCLUSION

Our results indicate that autologous implantation of NP induces thermal hyperalgesia and mechanical allodynia, and leads to an upregulation of fractalkine and its receptor in spinal neurons and glia, implicating fractalkine in association with radicular pain.

[Long-lasting low back pain and MRI changes in the intervertebral discs]

BACKGROUND

Although low back pain is usually temporary, some patients do not recover and need treatment. Therefore, it is important to uncover causal and contributing factors. Here we give an overview of recent research on MRI findings and genetic factors that may be important for development of long-lasting low back pain.

MATERIAL AND METHODS

A non-systematic search in PubMed and EMBASE was performed. The relevant research articles identified, as well as the authors' knowledge of the field formed the basis for this review.

RESULTS

It is generally accepted that low back pain often stems from intervertebral discs, facet joints and lumbar multifundi muscles. However, it is also known that many patients with pronounced disc degeneration have so-called Modic changes, i.e. MRI changes in bone marrow close to the vertebral endplates. Several recent studies have shown an association between such changes and pain. It has also been demonstrated that patients with Modic changes and low back pain often have concomitant inflammation and growth of nociceptive nerve fibers into the endplates. To which extent this occurs, may be partly based on genetics.

INTERPRETATIONS

Genetic factors may contribute to low back pain. New knowledge about genetic factors and Modic changes can create a basis for better diagnostics and more specific treatment of patients with long-lasting low back pain.

Percutaneous Laser Disc Decompression for the Treatment of Lumbar Disc Herniation: A Review

BACKGROUND

Discontinuation of the marketing of chymodactin has reawakened interest in other percutaneous techniques for treating lumbar disc herniation. Developed in the 1980s, the concept of laser disc decompression is based on the percutaneous introduction of an optical fiber into the intervertebral disc and administering laser energy. The procedure allows for the vaporization of a small amount of the nucleus pulposus and hence a reduction in the intradisc pressure and relief of radicular pain.

OBJECTIVES

To review of the literature and summarize the technical modalities, mechanism, indications for, and results of percutaneous laser disc decompression for treating lumbar disc herniation.

METHODS

We identified studies of percutaneous laser disc decompression published between January 1980 and June 2006 in the MEDLINE, EMBASE, and Cochrane Library databases. The search terms used were percutaneous laser disc decompression, laser, and spine or lumbar, disc or disk. The articles underwent a stepwise selection process on the basis of their title, abstract, and full text.

RESULTS

Experimental and clinical studies have investigated the modality of percutaneous laser disc decompression, but no consensus exists on the type of laser to use, the wavelength, duration of application, or appropriate energy applied. Studies have evaluated the impact of different techniques on the amount of disc removed, intradisc pressure, and damage to neighboring tissue. Several open studies have been published, but their methodology and conclusions are questionable, and no controlled study has been performed.

CONCLUSIONS

Although the concept of laser disc nucleotomy is appealing, this treatment cannot be considered validated for disc herniation-associated radiculopathy resistant to medical treatment.