Minimally invasive pain and spine interventions for low backache

Pravesh Kanthed; Nitika Vyas; Prateek Arora; Samarjit Dey

doi:10.4103/ijpn.ijpn_122_22

REVIEW ARTICLE

Year : 2022 | Volume : 36 | Issue : 4 | Page : 24-30

Minimally invasive pain and spine interventions for low backache

Pravesh Kanthed¹, Nitika Vyas¹, Prateek Arora², Samarjit Dey³
¹ Choithram Hospital and Research Centre, Indore, Madhya Pradesh, India
² Department of Anaesthesiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
³ Department of Anaesthesiology, All India Institute of Medical Sciences, Mangalagiri, Andhra Pradesh, India

Date of Submission	10-Dec-2022
Date of Decision	13-Dec-2022
Date of Acceptance	16-Dec-2022
Date of Web Publication	30-Dec-2022

Correspondence Address:
Dr. Prateek Arora
Department of Anaesthesiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/ijpn.ijpn_122_22

Abstract

Various pain generators can lead to low backpain. It includes conditions affecting the muscles, lumbar spine, joints, traversing and exiting nerve roots etc. The IASP named 2021 the year as the Global Year About Back Pain, highlighting its importance. Multiple modalities exist for the treatment of conditions causing low-back pain, including non-pharmacological therapies, drugs, percutaneous minimally invasive techniques and surgeries. This review aims at providing a cursory view of the common ailments causing low backache and its corresponding minimally invasive techniques.

Keywords: Low back pain, lumbar spondylosis, MIPSI, Sacroilitis

How to cite this article:
Kanthed P, Vyas N, Arora P, Dey S. Minimally invasive pain and spine interventions for low backache. Indian J Pain 2022;36, Suppl S1:24-30

How to cite this URL:
Kanthed P, Vyas N, Arora P, Dey S. Minimally invasive pain and spine interventions for low backache. Indian J Pain [serial online] 2022 [cited 2023 Mar 31];36, Suppl S1:24-30. Available from: https://www.indianjpain.org/text.asp?2022/36/4/24/366475

Introduction

Low back pain is an extremely common medical entity and the most common cause of disability in the population younger than 45 years. It is a major cause of work absenteeism with significant emotional, physical, and economic ramifications.^[1] Around four out of five people have lower back pain at some point in their lives. It is one of the most common reasons people visit health-care providers. Fortunately, the majority of cases resolve in 6 weeks with or without treatment.

The differential diagnosis of back pain is extensive, physical findings may vary from one examination to the next, and investigations are inconclusive quite often. Many potential etiologies are broken mainly into five primary categories.^[1]

Mechanical: Most commonly, this is due to injury to the spine, intervertebral discs, or soft tissues. Fractures such as spondylolisthesis can be both acute or chronic. Lumbago often is labeled as acute back pain or a strain to either the quadratus lumborum muscle or the paraspinal muscles. Disc herniation is a common type of traumatic back pain. Pregnancy is also a mechanical cause of back pain
Degenerative: Osteoarthritis of the spine includes facet joint osteoarthritis, sacroiliac joint osteoarthritis, spinal stenosis, and degenerative disc disease. Furthermore, osteoporotic compression fractures are also a degenerative process
Inflammatory: This is caused primarily due to inflammatory (seronegative) spondyloarthropathies such as ankylosing spondylitis. Sacroiliitis is most commonly seen
Oncologic: This is caused by lytic lesions to the spine, cancers of the marrow, or compressive nerve phenomena from adjacent space-occupying lesions, often presenting as pathological fractures
Infectious: Infections of the spine, discs, epidural abscesses, or muscular/soft tissue abscesses.

Pain often gets better with rest, physical therapy, and medication. In some cases, pain can make it difficult or impossible to walk, sleep, work, or do everyday activities. The goal of interventional pain management is to reduce the pain so that the patient can lead an active, pain-free life.

A considerable overlap exists in the etiology, and multiple etiologies can be present at the same time, in a patient. It is common for a patient to have a prolapsed disc as well as facet arthropathy as a pain generator for low backache. A meticulous history, clinical examination, and finally diagnostic blocks or minimally invasive pain and spine interventions (MIPSIs) help in clinching the diagnosis. These procedures have both diagnostic and therapeutic values. Several modalities or a combination can be used depending on the disease process, and although there is an increasing popularity of ultrasound, fluoroscopes remain the most commonly employed choice of imaging. In this narrative, the procedures have been described keeping fluoroscopy in mind.

The most common interventions for treating back pain are:^[2]

Epidural MIPSI

Interlaminar approach
Transforaminal approach-subpedicular and Kambin's triangle approach
Caudal approach.

Facet joint MIPSI

Intra-articular
Medial branch nerve block.

Sacroiliac joint MIPSI
Intradiscal procedures.

Discography
Intradiscal ozone (O3)
Intradiscal steroid
Platelet-rich plasma (PRP).

Epidural Minimally Invasive Pain and Spine Intervention

Epidural MIPSI is among the commonly performed procedures in managing pain secondary to disc herniation and radiculopathy with evidence demonstrated by multiple systematic reviews of controlled studies and evidence-based guidelines.^[2]

Interlaminar approach

The goal of this interventional pain medicine procedure is the relief of radicular pain and is a therapeutic option in the cervical, thoracic, or lumbar spine. Injectate typically is composed of a combination of anesthetics and steroids.

The interlaminar approach allows for medication spread over a larger area than transforaminal epidural injection and can be advantageous in patients with multi-level spinal pathology.^[3]

However, the intrinsic nature of the dorsal approach of interlaminar injection results in a limited ventral spread of injectate compared to transforaminal epidural MIPSI, which can limit efficacy in a pathology-dependent manner.^[3]

Indications

The clinical findings of patients who are most likely to benefit from epidural MIPSI are those who have back pain with a radicular component due to herniated nucleus pulposus.^[4] Radicular pain in the cervical spine may refer to pain radiating down the upper extremity, while in the lumbar spine, classic radicular pain radiates down the lower extremity. Physical examination findings may include those which correspond to radiculopathy, including a positive Spurling test for the cervical spine, or a positive straight leg raise for the lumbar spine.^[5],[6] Patients with spinal stenosis also may benefit from epidural MIPSI; however, recent studies continue to delineate optimal injectate composition.^[7],[8]

Transforaminal approach

Percutaneous injection-based therapies, including transforaminal epidural steroid injection (TFESI), are being used with increasing frequency to treat radiculopathy resulting from a herniated disc or degenerative lumbar spinal stenosis.^{[9],[10],[11]} In contrast to an interlaminar or a caudal epidural steroid injection, TFESI provides a low volume of concentrated medication to a selected nerve root/dorsal root ganglion [Figure 1].

Figure 1: Radiographic image of the lumbar spine (AP view) showing radiocontrast dye spread over the exiting nerve roots at L3 and L4 via the transforaminal approach

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The transforaminal approach is preferred for epidural steroid MIPSI because injection into the relevant nerve root may maximize drug concentration and it is possible to inject toward the anterior epidural space [Figure 2] of the nerve root related to symptoms, which is the site of discoradicular conflict.^[11],[12]

Figure 2: Radiographic image of the lumbar spine (lateral view) showing radiocontrast dye spread in the anterior epidural space

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There are two types of transforaminal approaches [Figure 3]: I. Subpedicular approach: Currently, the subpedicular approach is the most common method used clinically. In this method, the injection needle is progressed toward the safer triangle under the inferior surface of the pedicle to locate the superolateral spinal nerve related to symptoms.^[13] This location is favored because agents can be injected into the anterior epidural space, i.e., the inflammatory site between the back of the herniated intervertebral disc and the anterior nerve root dural sleeve. The risk of damaging the dura mater is decreased, as the injection needle goes through the border of the lateral upper intervertebral foramen.^[11],[14] However, Murthy et al.^[15] reported that the Adamkiewicz artery runs through the safe triangle and injection at this site might transfer agents within the artery or directly damage the vessel, which can even cause paraplegia.^[15]

Figure 3: (a) Schematic representation of “Kambin's triangle.” The hypotenuse is the exiting nerve; the base is the caudal vertebral body, and the height is the traversing nerve root. (b) Schematic description for TFESI with Kambin's triangle versus the subpedicular approach (target L5 nerve root). Ann Rehabil Med 2011;35:833-43. DOI: 10.5535/arm. 2011.35.6.833. TFESI: Transforaminal epidural steroid injection

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II. Kambin's triangle approach: Kambin's triangle is defined as a right-angle triangle over the dorsolateral disc. The hypotenuse is the exiting nerve root, the base (width) is the superior border of the caudal vertebra, and the height is the dura/traversing nerve root.^[16] The triangle is where endoscopic lumbar intervertebral disc surgery is conducted posterolaterally. Approaches used in this area have several merits, including increased safety, such as protection of the epidural and nervous system, prevention of venous congestion and chronic nervous edema, and prevention of epidural bleeding and scarring in tissues around the nerve and epidural. Crall et al.^[17] reported no statistical differences in the immediate treatment effects from injections into four parts of the intervertebral foramen, noting that the preganglionic approach did not show difference or superiority in treatment effects when compared to the existing subpedicular approach.

Caudal epidural minimally invasive pain and spine intervention

Caudal epidural MIPSI has been used for the management of chronic low back pain (CLBP) and sciatica. In 1901, Sicard introduced the injection of cocaine through the caudal route into the epidural space and ever since caudal epidural steroid MIPSI is commonly used when dealing with chronic low back and/or radicular pain.^[18] Caudal epidurals are considered the safest and easiest, with minimal risk of inadvertent dural puncture, even though requiring relatively high volumes.^[19],[20] However, the recent literature has shown that while caudal epidural injections may not be superior to either interlaminar or transforaminal, they may provide equal effectiveness.^{[19],[20],[21],[22],[23],[24],[25],[26]}

The patient is usually placed in a prone position for fluoroscopy-guided caudal epidural injection. In the lateral view of fluoroscopy, the sacral hiatus could be identified as an abrupt drop-off at the end of the S4 lamina^[27] [Figure 4]. The needle trajectory can be visualized and navigated accordingly into the sacral canal, not beyond the S2 foramen. By injecting contrast medium under fluoroscopy, the placement of the needle tip within the sacral epidural space can be verified and intravascular or intrathecal needle tip placement can be detected [Figure 5].

Figure 4: Sagittal view of the sacrum. SH red double-ended arrow: anterior-posterior diameter of sacral hiatus at its apex. Biomed Res Int 2017;2017:9217145. DOI: 10.1155/2017/9217145. SH: sacral hiatus

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Figure 5: Radiographic image showing the spread of contrast agent in the caudal space (fir tree appearance)

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Facet Joint Minimally Invasive Pain and Spine Intervention

The facet or zygapophyseal joints are considered to be common sources of chronic axial spinal pain.^[28],[29] In addition to causing localized spinal pain, facet joints may refer pain to adjacent structures. Lumbar facet joints may refer to pain in the back, buttocks, and proximal lower extremities. Referred pain may assume a pseudo-radicular pattern, making the underlying diagnosis difficult to confirm, without the use of diagnostic injections.^[28],[29] A facet injection is an injection of local anesthetic and steroids into a joint in the spine. A medial branch block (MBB) injection is similar, but the medication is placed outside the joint space near the nerve that supplies the joint called the medial branch (a steroid may or may not be used).

Intra-articular facet minimally invasive pain and spine intervention

Facet joint MIPSI is one of the most commonly performed procedures among all spinal interventions.^[30] Facet joint pain can arise from osteoarthritis, segmental instability, trauma, meniscoid impingement, and inflammatory synovitis.^[31],[32] Patients with facet joint pain may present with symptoms of neck pain, back pain, and pain worsened with hyperextension, bending laterally, and rotation. Facet-mediated pain is typically axial, with rare radiation into the upper extremities or lower extremities in cervical and lumbar facet diseases, respectively. Facet joint pain is a diagnosis of exclusion after other etiologies have been ruled out. Thus, performing facet joint MIPSI under image guidance has become a valuable tool in diagnosing facet joint pain and may provide therapeutic benefits.^[33]

Here, an injection is made into the joint space of the facet joint in the spine. A recent narrative review by Bogduk^[34] suggested that intra-articular facet joint injections were no better than placebo for chronic lumbar spine pain. Slipman et al.,^[35] in a review of the evidence for the use of zygapophyseal injections and radiofrequency denervation in the treatment of low back pain, found limited evidence for intra-articular injections in the lumbar spine and moderate evidence for radiofrequency neurotomy in the lumbar spine. Fuchs et al.^[36] investigated the efficacy and safety of intra-articular sodium hyaluronate compared with intra-articular glucocorticoids (triamcinolone acetonide) in the treatment of chronic nonradicular lumbar pain. Nash^[37] compared the effects of intra-articular injections with medial branch MIPSI.

Medial nerve branch minimally invasive pain and spine intervention

Medial branch nerves richly supply the facet joints. Each facet joint is innervated by both the medial branch of the primary dorsal ramus of the nerve exiting at its level and the medial branch of the above vertebral level^[38] [Figure 6].

Figure 6: Schematic representation of lumbar zygapophyseal (facet) joint and its innervation by the medial branch nerve. ADOPTED from MBBs-La Plata Physical Medicine. Available from: https://laplataphysicalmedicine.com/medial-branch-blocks. MBBs: Medial branch blocks

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Often, history of present illness, physical examination, and radiologic evidence are insufficient in correctly diagnosing facet-mediated CLBP; therefore, positive response to a series of diagnostic lumbar MBBs with local anesthetics is a necessary precursor to lumbar medial branch nerve RFA.^[39],[40] Positive diagnostic lumbar MBB is loosely defined as experiencing transient >80% pain relief of CLBP on a single or series of two diagnostic lumbar MBBs. Interestingly, some patients with CLBP achieve significant and protracted pain relief and/or functional improvement after diagnostic lumbar MBBs alone and do not require lumbar RFA. In these patients, the analgesic effects of local anesthetics appear to be prolonged, providing pain relief to some for weeks to months, outlasting the pharmacokinetics of the anesthetics employed.^[41]

Sacroiliac Joint Minimally Invasive Pain and Spine Intervention

The sacroiliac joint has been implicated as the primary source of pain^{[42],[43],[44],[45],[46],[47],[48]} in 10%–26.6%^{[49],[50],[51]} of cases with suspected sacroiliac joint pain. The sacroiliac joint is a diarthrodial joint^[52] which receives innervation from the lumbosacral nerve roots.^{[53],[54],[55],[56],[57],[58],[59],[60],[61],[62]} The rationale for the use of sacroiliac joint MIPSI as the gold standard for diagnosing sacroiliac joint pain is based upon the fact that sacroiliac joints are richly innervated and are capable of being a source of low back pain and referred pain in the lower extremity.^{[42],[43],[44],[45],[46],[47],[48],[49],[50],[51],[53],[54],[55],[56],[57],[58],[59],[60],[61],[62],[63],[64],[65],[66]} The sacroiliac joint can be anesthetized with intra-articular injection of local anesthetic performed under fluoroscopic guidance with confirmation of contrast spread throughout the joint space [Figure 7]. Intra-articular injections with a steroid and/or radiofrequency neurotomy of the S1-S3 lateral branches and L5 dorsal rami have been employed to manage chronic sacroiliac joint pain.^[42],[47] The systematic evaluation of diagnostic and therapeutic interventions of the sacroiliac joint showed moderate evidence of the accuracy of diagnostic sacroiliac joint MIPSI with a prevalence of 10%–26.6% and a false-positive rate of 20%–22%.^{[49],[50],[51]}

Figure 7: Radiographic image showing needle placement and radiocontrast spread in the sacroiliac joint

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Intradiscal Procedures

Intradiscal procedures focus on introducing substances inside the disc which is suspected to be the pain generator. These can be diagnostic alone or may involve the administration of the following therapeutic agents. Some commonly performed procedures include the following.

Discography

A lumbar discogram, also called lumbar discography, is a minimally invasive, presurgical diagnostic test devised to determine if an intervertebral disc in the lower spine is the primary cause of back pain with or without leg pain (sciatica). The test involves injecting a radiopaque contrast agent into the central part of the intervertebral disc that is suspected to be the source of pain [Figure 8]. The injection increases pressure within the disc and stimulates symptoms.^[67]

Figure 8: Radiographic image showing radiocontrast spread inside the disc in (a) Anteroposterior and (b) Lateral views

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Provocative discography, despite the invasiveness and high false-positive rates (33%–35%), is still the gold standard for the diagnosis of DLBP.^[68] The test is positive when it presents contrast leakage and reproduces patients' concordant pain during the procedure. A study showed that positive provocative discography screening significantly improved surgical outcomes.^[69]

Ozone therapy

O3 is an allotropic form of oxygen, primarily known for its ecological properties, industrial application, and therapeutic effects. Questions persist concerning its potential toxicity as an oxidant agent versus its reported clinical efficacy. Several mechanisms of action have been proposed to explain the efficacy of O3 therapy including analgesic, anti-inflammatory, and oxidant actions on proteoglycans (e.g., in the nucleus pulposus). O3 is administered in the form of an oxygen-O3 gas mixture at nontoxic concentrations ranging from 1 μg to 40 μg of O3 per mL of oxygen, using various percutaneous methods.^[70] O3 is a strong oxidizing agent that quickly reacts and oxidizes the proteoglycans in the nucleus pulposus, which results in a small reduction of disc volume and subsequently contributes to pain relief. The suggested premise is that a small volume reduction results in a significant decrease in pressure. In addition, it has been shown to have anti-inflammatory/analgesic and natural antibacterial and antiviral effects.^[70],[71]

Intradiscal steroid

When degenerative changes exist in the nucleus pulposus, some of the force between the vertebral end plates is exerted directly on the annulus fibrosus. Degeneration of some central fibers appears first, subsequently leading to tears and fissures. Although in the early phases these changes are microscopic in appearance, they cause an inflammatory reaction in the surrounding, sensitive, longitudinal ligaments of the spine. This creates a clinical picture of acute low back pain.

Inflammation, either from direct chemical irritation or secondary to an autoimmune response to the nucleus pulposus, has been implicated as the primary pain source.^[72] Both steroids and nonsteroidal anti-inflammatory drugs have partial effectiveness in treating the pain associated with inflammation.^[73]

When the symptom of pain is thought to result from inflammation, it is natural to think that an anti-inflammatory agent can be useful for treatment. Therefore, the rationale for using intradiscal steroids is to suppress the inflammation within the disc, thereby alleviating the patient's symptoms.^[74]

Platelet-rich plasma

PRP is defined as autologous blood with platelet concentrations above the physiological baseline. It is obtained by a centrifugation process which separates the liquid and solid components of blood.^[75],[76] PRP is postulated to promote endogenous healing processes; however, the mechanism remains unclear. It is reported that healing occurs after PRP stimulates the recruitment, proliferation, and differentiation of cells involved in regeneration via several growth factors and proteins released from the platelets.^[77] Nonetheless, platelets contain antibacterial proteins and are capable of migrating to injury sites.^[78] Disc degeneration is a sequential process possibly starting with a circumferential tear in the annulus fibrosus that progresses to a radial tear, herniation, loss of disc height, and resorption.^[79] In skin wound healing, platelets can bring disrupted cells closer together. Likewise, platelets pull the edges of degenerated disc tears together, leading to the healing of cells. However, this is quite challenging due to the avascular nature of discs, which are not highly vascularized like skin.^[79]

Conclusion

Many modalities and interventions can be used to treat back pain. As each patient is different from another, so has to be its treatment plan. No one interventional procedure can be superior to another. Correct diagnosis based on history, clinical examination, and diagnostic and therapeutic interventions, can give a positive outcome in these patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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