28 Interventional and Semi-invasive Procedures
for Low Back Pain and Disc Herniation
M.K. Schäufele
28.1
Terminology
Semi-invasive procedures for low back pain and disc herniations include a wide range of procedures. For the purpose of this chapter, the focus will be on spinal in- jection procedures, radiofrequency denervation proce- dures, and advanced interventional pain management procedures. The terminology of the different proce- dures is described in the corresponding sections.
28.2
Surgical Principle
Percutaneous spinal procedures are generally per- formed under fluoroscopic X-ray guidance, except for certain special procedures, such as vertebral biopsies, which may be performed under CT guidance. All these procedures can be performed on an outpatient basis.
They can be safely done under local anesthesia and when necessary, under conscious sedation. A dedicated procedure suite is recommended with radiolucent pro- cedure table, monitoring equipment, and a high quality C-arm. Percutaneous spinal injection procedures de- mand an excellent three-dimensional knowledge of the radiographic anatomy of the spine.
After the patient is positioned on the procedure ta- ble, the C-arm is positioned to identify the target tissue.
The “universal lumbar view” (Fig. 28.1) allows identifi- cation of all target tissues. It is obtained by tilting the C- arm to accommodate for the lumbar lordosis, followed by rotating the C-arm into a 20 – 30° oblique view. Usu- ally, a 22-gauge or 25-gauge spinal needle of various lengths is then inserted parallel to the X-ray beam (“tunnel view”) and slowly advanced under frequent radiographic imaging with AP, oblique, and lateral C- arm projections. Once the target area is reached and af- ter negative aspiration, a small amount of non-ionic contrast (such as Omnipaque 300) is injected. The in- jection of dye confirms appropriate positioning of the needle tip into the target tissue. Depending on the type of procedure, target tissues such as the nerve root sleeve, epidural space, or facet joint capsule can be
identified. Dye injection also ensures that the needle is not placed inadvertently in the intravascular space.
Next, a combination of a small amount of local anes- thetic and, in the case of a therapeutic injection, a pre- servative-free steroid (such as Depo-Medrol or Celesto- ne Soluspan) is injected. The needle is removed and the patient is observed for about 30 – 45 minutes in the re- covery area. Significant side effects are rare and the ma- jority of patients can resume normal activities the next day.
Fig. 28.1. Universal radiographic lumbar view (“Scottie dog view”) allows target visualization for all lumbar spinal injec- tions.1 Transforaminal epidural, 2 interlaminar epidural, 3 in- tra-articular facet joint injection,4 medial branch injection, 5 intradiscal access for discography and intradiscal procedures
For the purpose of this chapter, the most commonly performed interventional spine procedures are dis- cussed, including epidural steroid injections, facet (zy- gapophyseal) joint injections, and radiofrequency neu- rotomies as well advanced interventional pain proce- dures, such as spinal cord stimulators and intrathecal drug delivery systems.
28.3 History
The first description of a caudal injection for patients with intractable sciatica was described in 1925 [14]. Ro- becchi first described injection of steroids into the spinal canal in 1952 [11]. The discovery of high levels of inflam- matory cytokines in a herniated nucleus pulposus, such as phospholipase A2 by Saal in 1990, as well as other cyto- kines, contributed to the understanding of the significant inflammatory component that contributes to radicular pain [13]. Bogduk postulated that for “any structure to be deemed the cause of back pain, this structure should have been shown to be a source of pain in patients” [3]. This led to the development and use of precision injection techniques to selectively block pain transmission from potentially painful structures in the spine, such as the segmental spinal nerve roots, facet joints, and sacroiliac joints. In addition to the usefulness of these injection techniques for diagnostic purposes, additional injection of anti-inflammatory agents such as glucosteroids or ap- plication of radiofrequency energy for denervation pro- cedures have expanded the therapeutic spectrum. Simi- lar to advances in interventional cardiology, interventio- nal spine procedures have become important diagnostic and therapeutic tools for spine specialists and stand in the treatment algorithm between the more traditional pharmaceutical therapies/physical medicine techniques and traditional open surgery. The advances in digital fluoroscopic imaging and mobile C-arm technology have greatly enhanced the ability to perform these procedures with maximum precision and safety for the patient.
28.4 Advantages
Outpatient procedure
Procedures are performed under local anesthesia or mild conscious sedation
Patients can resume regular activities the following day
Minimal side effects No skin incision
No permanent structural alteration of the spinal canal or surrounding soft tissues
Useful for diagnostic and therapeutic purposes
28.5
Disadvantages
Therapeutic effects are often temporary Significant learning curve
Multiple injections may be necessary to identify the pain generator
28.6 Indications
One has to differentiate between spinal injections for diagnostic purposes and spinal injections for thera- peutic purposes. The pain generator is often unclear in patients with chronic spinal pain. The history and physical examination often cannot reliably identify the source of the patient’s pain [8]. Furthermore, imaging studies such as X-ray, myelography, and MRI have a high rate of false-positive abnormalities that often do not correlate with the patient’s pain [1]. Precision diag- nostic injections are useful to determine the origin of a patient’s pain. The double-block technique is recom- mended for diagnostic procedures to decrease the number of false-positive responses. First, a small amount of short-acting local anesthetic is injected into the target tissue (such as lidocaine 2 %). If the patient experiences at least 50 %, preferably 70 % of pain relief, the procedure is repeated with a second, longer-acting local anesthetic (such as Bupivacaine 0.5 %) to confirm the diagnosis.
In case of therapeutic spinal injections, the goal is to minimize the patient’s pain through application of an anti-inflammatory medication, usually a steroid, at the site of pain and inflammation. Patients with acute or chronic radiculopathy may benefit from epidural ste- roid injections, whereas patients with facet-mediated pain may benefit from facet injections, medial branch injections, or radiofrequency neurotomies to dener- vate the painful facet joints. Chronic neuropathic pain syndromes may benefit from an implanted spinal cord stimulator, and patients with complex, intractable pain syndromes may benefit from intrathecal drug delivery systems.
28.7
Contraindications
Bleeding diathesis and anticoagulant therapy, including platelet-inhibitors.
Pregnancy.
Bacterial infection.
Allergy to non-ionic contrast dye or local anes- thetics.
Patients with diabetes mellitus need to monitor
their postinjection blood sugar if steroids are injected.
Patients with artificial heart valves may require treatment with preoperative antibiotics.
28.8
Patient’s Informed Consent
Patients may experience weakness or numbness after the injection consistent with the therapeutic duration of the local anesthetic that was injected. Therefore, pa- tients should not drive until they have normal sensa- tion and strength. If steroids were injected, patients may experience a steroid flush, irritability, and insom- nia for a few days as well as stomach irritability. Injec- tion site soreness usually subsides within a few days.
Occasionally, a temporary increase in pain is noted. In case of interlaminar epidural steroid injections, the risk for a spinal headache exists in the inadvertent case of an intrathecal injection. In case of radiofrequency neuro- tomies, temporary neuralgias are not uncommon but usually subside within a few weeks. Significant side ef- fects, such as epidural hematomas resulting in spinal cord injury, epidural abscesses, discitis, and intravas- cular injections resulting in permanent neurological deficits have been described but are extremely rare [5, 6, 9]. Implantable devices may pose the risk of infec- tion, including epidural abscess and meningitis, lead and catheter migration, medication overdose, and hardware failure.
28.9
Surgical Technique
The requirements for interventional spine procedures include a sterile operating room or procedure room, monitoring equipment for blood pressure, pulse oxi- metry and EKG, high-quality digital C-arm fluorosco- py, sterile preparation, resuscitative equipment, nee- dles, gowns, injectable agents, intravenous fluids, seda- tive agents, and trained personnel for preparation and monitoring of the patients.
28.9.1
Facet (Zygapophyseal) Joint Injections
Diagnostic injections of the facet (“Z”) joint can be per- formed to test the hypothesis that the target joint is the source of the patient’s pain [4]. These joints can be anesthetized either with intra-articular injections of lo- cal anesthetic or by anesthetizing the medial branches of the dorsal rami, the innervating branches to the tar- get joint. Each joint is innervated by medial branches of the corresponding segmental nerve and the segmental
nerve above. If the pain is not relieved, the joint cannot be considered the source of the pain. True positive re- sponses are secured by performing controlled blocks, usually with comparative local anesthetic blocks: the same joint is anesthetized by using a local anesthetic of different duration.
Lumbar facet joints have been shown to be capable of being the source of low back pain with referred pain into the lower limb. History and physical examination findings are unreliable in determining facet joint pain [7]. Therefore, injection of these joints is necessary to prove or refute the diagnosis of facet-mediated pain.
The facet joint is a true synovial lined joint allowing the spine to flex, extend, and rotate. The most common cause of facet joint disease is osteoarthritis. The senso- ry nerve endings entering the facet joint capsule be- come irritated by an inflammatory process resulting in a sensation of pain.
If facet joint injections are performed for therapeu- tic purposes, steroids are added to the injectate. For lumbar facet joint injections, the target joint is lined up through an oblique C-arm projection (“Scottie dog view”; Fig. 28.1). The C-arm is rotated to the contralat- eral side until the posterior facet joint line just becomes visible. Injection of the lower lumbar facet joints re- quires usually more rotation than the upper facet joints. In case of severely degenerated joints, visualiza- tion of the facet joint line may be difficult and may re- quire rotation of the C-arm to the ipsilateral side to al- low entry into the joint. Once the facet joint line is iden- tified, a 22-gauge or 25-gauge needle is advanced into the joint. The joint is usually most accessible in the su- perior or inferior recess of the joint capsule. Once the needle has entered the joint, a distinct change in resis- tance is noted. Intra-articular placement is confirmed with injection of a small amount of non-ionic contrast, such as 0.2 cc Omnipaque 300 (Fig. 28.2a, b). Next, a small amount of local anesthetic such as 0.5 – 1 cc lido- caine 1 % or 2 %, or Bupivacaine 0.25 % or 0.5 % is in- jected. For therapeutic injections, a small amount of steroid such as 20 – 40 mg Depo-Medrol is added.
28.9.2
Medial Branch Injections
Each facet joint is innervated by two medial branches.
In the case of the L4-5 facet joint, for example, the facet
joint is innervated by the medial branches of the dorsal
rami of L3 and L4. Therefore, successful treatment of
the target facet joint with spinal injections requires an
injection of the two supplying medial branches. For in-
jection in the lumbar spine, the universal spine view
(Fig. 28.1) is again used. The needle is placed in the
groove where the transverse process joins the superior
articular process. In the lateral view, the needle should
remain posterior of the neuroforamen. A small amount
a b Fig. 28.2a, b. Right L4-5 intra-articular facet injections, AP and lateral
of local anesthetic such as 0.5 cc lidocaine 1 – 2 % or 0.5 cc Marcaine 0.25 – 0.5 % is injected. For therapeutic injections, a small amount of steroid such as 20 – 40 mg Depo-Medrol is added.
28.9.3
Medial Branch Radiofrequency Neurotomies (“Facet Denervation”)
If a patient experiences 50 %, preferably 70 %, relief of pain from diagnostic intra-articular facet joint injec- tions or medial branch injections, but without long- term relief, they can be considered for radiofrequency
a b
Fig. 28.3a, b. Bilateral C4, C5 medial branch radiofrequency neurotomy (denervation of the C4 – 5 cervical facet joint bilaterally), AP and lateral; the patient is s/p C5/6 ACDF
neurotomies with the goal to provide the patient with
longer lasting pain relief. With proper technique, pa-
tients may have significant pain relief for approximate-
ly 6 – 12 months in the lumbar spine, or 1 – 2 years in the
cervical spine. The needle placement is similar to the
technique described for medial branch injections. Spe-
cialized electrodes and radiofrequency equipment is
commercially available. Precise needle placement is
necessary for a successful procedure (Fig. 28.3). Radio-
frequency heating is usually performed at 70 – 80 °C be-
tween 60 and 90 seconds in one to three different loca-
tions in the target area. Prior to the lesioning, sensory
testing is performed to assure proper placement of the
needle close to the medial branch. Motor testing is per- formed to assure that the needle tip is placed not too close to the segmental motor nerve.
28.9.4
Epidural Injections
Several different techniques have been described for epidural steroid injections. They include interlaminar epidural steroid injections, selective nerve root injec- tion/transforaminal epidural steroid injections, and caudal epidural steroid injections.
28.9.4.1
Caudal Epidural Steroid Injection
Caudal epidural steroid injection is the least specific epi- dural steroid injection, but is also technically the easiest to perform. The patient is placed in the prone position.
The caudal epidural space is approached via the sacral hiatus. The hiatus can usually be identified manually, but fluoroscopic placement assures placement into the spinal canal and not into the soft tissues. Usually a 22- gauge, 3.5-inch needle is placed through the sacral hia- tus up to the S2 – 3 level. On the AP view, the needle tip should not extend significantly beyond the intersecting line between the sacroiliac joints. The needle should be positioned in the midline unless the patient complains about radicular symptoms only on one side. To confirm epidural flow, 1 – 2 cc of contrast dye, such as Omnpa- que 300, is injected. Intravascular uptake is not uncom-
a b
Fig. 28.4a, b. Lumbar interlaminar epidural steroid injection, AP and lateral. Note the contrast flow primarily in the dorsal epidu- ral space
mon and needs to be recognized. If this is the case, the needle needs to be repositioned. The thecal sac extends to the S2 level in adults and dural puncture is possible.
Caudal epidural steroid injections usually require larg- er volumes of medication; an injection of 10 cc is neces- sary to reach the L4-5 level. Commonly, a combination of a lower concentration local anesthetic, such as lido- caine 1 % or Bupivacaine 0.25 %, 6 – 10 cc, and a steroid such as 80 – 120 mg Depo-Medrol is injected.
28.9.4.2
Interlaminar Epidural Steroid Injection
This approach is similar to the classic anesthesiologist’s approach of the interlaminar space for epidural anes- thesia. The patient is placed in the prone position. Us- ing the universal view (Fig. 28.1), the interlaminar win- dow on the affected side is identified. An interlaminar epidural steroid injection should not be performed on a patient with a previous spinal surgery at this level be- cause the posterior epidural space may be altered and injection may result in an intrathecal injection, possi- bly resulting in spinal block and postpuncture head- aches. The needle is advanced into the posterior epidu- ral space, usually with the loss of resistance technique.
A glass syringe is filled with air or sterile saline. The
needle is slowly advanced through the ligamentum fla-
vum. Once loss of resistance is noted, epidural place-
ment is confirmed. Aspiration should be negative for
CSF or blood. To confirm epidural placement, 1 or 2 cc
of contrast dye is injected (Fig. 28.4). A combination of
2 – 5 cc of local anesthetic such as lidocaine 1 % or Bupi- vacaine 0.25 % and steroid such as 40 – 80 mg Depo- Medrol is injected.
28.9.4.3
Selective Nerve Root Injection/Transforaminal Injection With the transforaminal technique, the needle tip is placed superior to the nerve root and anterior into the epidural space. This technique allows specific blockade of one nerve root with a small amount of local anesthet- ic and can provide helpful diagnostic information about the source of a patient’s pain, especially in pa- tients with unclear history and physical findings and multilevel abnormalities on imaging studies. The pa- tient is placed in the prone position on the fluoroscopy table. A small gauge (22-gauge or 25-gauge) spinal nee- dle is inserted into the anterior and superior aspect of the corresponding neural foramen using the universal view (Fig. 28.1). One has to be careful with advancing the needle once the neural foramen is entered, to avoid nerve root injury. Once the needle is placed successful- ly in the anterior and superior aspect of the neural fora- men and not more medial than the 6 o’clock position of the pedicle in the AP view, a small amount of contrast such as 0.5 – 1 cc Omnipaque is injected (Fig. 28.5).
Next, a combination of 1 – 3 cc lidocaine 1 – 2 % or Bupi- vacaine 0.25 – 0.5 % with steroid is injected (40 – 80 mg Depo-Medrol or 6 – 12 mg Celestone Soluspan). For a selective nerve root injection, which serves primarily for diagnostic purposes by specifically blocking only one nerve root, the injection is stopped once the con- trast has reached the medial wall of the pedicle to avoid
a b
Fig. 28.5a, b. Lumbar transforaminal epidural steroid injection, AP and lateral. Note the contrast flow along the nerve root into the anterior epidural space
spill into the epidural space. The amount of contrast in- jected is noted and the same amount of local anesthetic (usually of higher concentration) such as lidocaine 2 – 4 % or Marcaine 0.5 – 0.75 % is injected. The patient is observed after the procedure and appropriate and successful blockade of the segmental spinal nerve is confirmed with corresponding motor and sensory defi- cits. The patient’s change in pain is recorded on a pain diagram.
28.9.5
Sacroiliac Joint Injection
The sacroiliac joint injection is best performed under
fluoroscopic guidance with contrast enhancement. Ro-
senberg et al. [12] showed that intra-articular injection
into the joint was achieved in only 22 % of patients with
clinically guided sacroiliac joint injections. The pur-
pose of sacroiliac joint injections is primarily diagnos-
tic. Some patients can achieve prolonged relief with in-
tra-articular steroid injections into the joint, but often
the results are only temporary. Radiofrequency tech-
niques to denervate the sacroiliac joint so far have not
produced good reliable clinical outcomes. The patient
is placed prone on the fluoroscopy table. From an AP
position, the C-arm is slowly rotated until the anterior
and the posterior joint lines separate. The needle tip
should be placed into the lower aspect of the joint ap-
proximately 1 cm above its inferior joint line, where the
joint is most accessible. A 22-gauge 3.5-inch spinal nee-
dle is advanced into the joint. Once the needle is in the
joint, a change in resistance is noted. Intra-articular in-
jection is confirmed with 0.5 – 1 cc of contrast dye
Fig. 28.6. Intra-articular sacroiliac injection with arthrogram, AP
(Fig. 28.6). AP and lateral images can be used to deter- mine if capsular tears exists. A combination of 1 – 2 cc of local anesthetic such as lidocaine 1 – 2 % or Bupiva- caine 0.25 – 0.5 % with or without steroids is then in- jected.
28.9.6 Discography
Discography is a diagnostic procedure to determine the source of a patient’s low back pain. It is performed in patients in whom discogenic pain is suspected. Discog- raphy is the only functional test to determine if a pa- tient’s disc is painful. Contrast material is injected into the nucleus pulposus through a percutaneously placed needle. The most important assessment is the patient’s pain response to the injection of non-ionic contrast in- to the nucleus. In addition, information about the disc morphology and imaging of possible fissures and tears into the annulus are obtained. This procedure is usually performed on patients who have primarily axial back pain and have not responded to non-surgical treat- ments. These patients are usually considered for intra- discal therapies or fusion surgeries. The patient is placed in an oblique position on the procedure table.
The needles are usually placed opposite to the patient’s painful side through a posterolateral approach, using the universal view for lumbosacral injections (Fig. 28.1). Intradiscal access is usually achieved by a double-needle technique using an 18-gauge introducer needle through which a 25-gauge needle is placed into the center of the disc. Alternatively, a 22-gauge 5- or 7- inch spinal needle can be placed directly into the disc
by a single-needle technique. The needle is placed along the center of the X-ray beam into the inferior as- pect of the disc to avoid injury of the nerve root. Nee- dle position is confirmed in AP and lateral projections in the center of the disc. Non-ionic contrast dye is in- jected either manually or with manometry into the disc. A maximum of 3 cc of dye is injected into the disc and the pain response is recorded (VAS scale;
Fig. 28.7). Injections with manometric measurements allow standardization of the pain responses. The Inter- national Spinal Injection Society recommends that pa- tients with discs painful at 15 psi over opening pres- sure are considered to have a positive discogram, and patient’s who have concordant pain between 15 and 50 psi over opening pressure are considered to have a probable painful disc at this level. The opening pres- sure is a measure of the internal disc pressure and re- fers to the initial appearance of dye in the disc with in- jection. Intradiscal placement of needles into one or two adjacent presumably normal discs is recommend- ed to obtain a “normal control level.” Discography is operator dependent and requires significant experi- ence on the operator’s part.
28.9.7
Epidural Adhesiolysis
The purpose of percutaneous epidural lysis of adhe- sions is to perform a mechanical and chemical lysis of adhesions in the epidural space, which may have formed after previous surgery or previous inflammato- ry processes with resulting scar formation in the epidu- ral space. This can be accomplished through an epidu- ral catheter or spinal endoscope. The patient is placed in the prone position. A special epidural catheter (Racz catheter) or spinal endoscope is placed into the epidu- ral space, usually through a caudal approach. Non-ion- ic dye is injected to visualize scar formation indirectly by contrast filling defects. A spring-guided catheter is then placed directly into the scar formation. Attempts are made for mechanical disintegration of the scar.
Chemical adhesiolysis is then attempted by injection of a combination of local anesthetic, hypertonic saline, and a steroid. Traditionally, this procedure has been performed as an inpatient procedure with serial injec- tions over a 3-day period. Recently, this procedure is more commonly done as single injection as an outpa- tient procedure. With a spinal endoscope, the scar for- mation can be directly visualized and mechanically al- tered.
28.9.8
Implantable Therapies
Spinal cord stimulation systems and implantable intra-
thecal devices such as intrathecal opioid pumps are
a b
Fig. 28.7a, b. Lumbar discogram L3-4, L4-5, L5-S1. Note the large posterolateral annular tears with contrast extravasation at L4-5 and small annular tear at L5-S1; normal disc morphology of L3-4
considered advanced interventional pain management procedures and are appropriate treatment options for chronic pain syndromes that have not responded to other less invasive treatments. Spinal cord stimula- tions are primarily indicated for patients with chronic neuropathic pain such as chronic radicular pain and chronic regional pain syndromes. In the majority of cases, an epidural lead is placed as trial stimulation, usually in the thoracic spine for lower extremity pain syndromes. This lead is left with an external program- mer for about a week to determine the effectiveness of the treatment. If the patient reports at least 50 % im- provement of pain, a permanent system is implanted.
Most of the currently used systems are fully implanted, similar to pacemakers (Fig. 28.8). They can be activat- ed through telemetry by the patient or health care pro- vider.
Intrathecal opioid pumps can be of great benefit for patients with difficult and severe chronic pain syn- dromes, especially in cancer pain. They are increasing- ly used for chronic benign pain syndromes that are not otherwise controllable. In most cases, the patient un- dergoes testing through a temporary intrathecal appli- cation (single-shot of temporary catheter) of opioids to determine the therapeutic effect. If this test provides significant pain relief, the system is then fully implant- ed. An intrathecal catheter is implanted and connected
with a subcutaneous medication reservoir, similar in size to a hockey puck. This medication reservoir con- tains a pump. Usually, the reservoir is filled with mor- phine. Other pharmacologic agents, such as local anes- thetics, can be used as well. The pumps require fre- quent refills, sometimes once a month.
28.10
Postoperative Care and Complications
Most patients are usually monitored for about 30 – 45 minutes after the procedure. In the case of epi- dural steroid injections, they should be specifically as- sessed for signs of spinal block, which would indicate intrathecal placement of the needle. The patient should not be discharged before motor and sensory deficits have resolved. Complications for all these procedures are rare and have been discussed in the section on pa- tient’s informed consent.
28.11 Results
The scientific evidence is summarized for each of the
discussed procedures according to the classification
a b
Fig. 28.8. Implanted spinal cord stimulator; patient is s/p L5-S1 fusion for spondylolisthesis with postoperative persistent back and leg pain. a a. p. view, b lateral view
Table 28.1. Designation of levels of evidence (ASIPP, adapted from Manchikanti 2000) [10]
Level I Conclusive: Research-based evidence with multi- ple relevant and high quality scientific studies or consistent reviews of meta-analyses
Level II Strong: Research-based evidence from at least one properly designed randomized, controlled trial of appropriate size (with at least 60 patients in the smallest group); or research-based evi- dence from multiple properly designed studies of smaller size; or at least one randomized Level III Moderate: Evidence from a well-designed small
randomized trial or evidence from well-designed trials without randomization, or quasi random- ized studies, single group, pre-post cohort, time series, or matched case-controlled studies or pos- itive evidence from at least one meta-analysis Level IV Limited: Evidence from well-designed non-ex-
perimental studies from more than one center or research group
Level V Indeterminate: Opinions of respected authori- ties, based on clinical evidence, descriptive stud- ies, or reports of expert committees
published by the American Society for Interventional Pain Physicians (Table 28.1).
28.11.1
Diagnostic Facet Joint Injection
The validity, specificity, and sensitivity of facet joint in- jections are considered strong in the diagnosis of facet joint pain.
28.11.2
Therapeutic Intra-articular Facet Joint Injections
There is strong evidence of short-term relief and limit- ed evidence of long-term relief for chronic neck and low back pain.
28.11.3
Therapeutic Medial Branch Injections
There is some strong evidence of short-term relief and
moderate evidence of long-term relief of pain of facet
joint origin.
28.11.4
Medial Branch Neurotomies
There is strong evidence of short-term relief and mod- erate evidence of long-term relief of chronic spinal pain of facet joint origin.
28.11.5
Caudal Epidural Steroid Injections
There is strong evidence for short-term relief and mod- erate evidence for long-term relief.
28.11.6
Interlaminar Epidural Steroid Injections
There is moderate evidence of short-term relief and limited evidence for long-term relief.
28.11.7
Diagnostic Transforaminal Epidural Steroid Injections The current evidence provides moderate evidence of transforaminal epidural steroid injections in the pre- operative evaluation of patients with negative or incon- clusive imaging studies, but with clinical findings of nerve root irritation.
28.11.8
Therapeutic Transforaminal Epidural Steroid Injections There is strong evidence for short-term and long-term relief.
28.11.9
Sacroiliac Joint Injections
The evidence of specificity and validity of sacroiliac joint diagnostic injections is moderate.
28.11.10
Epidural Adhesiolysis
There is moderate evidence for short-term and long- term relief with repeat interventions.
28.11.11 Discography
The evidence for lumbar discography is strong for dis- cogenic pain provided lumbar discography is per- formed based on the history, physical examination, im- aging data, and analysis of other precision diagnostic techniques.
28.11.12
Spinal Cord Stimulation
The evidence for spinal cord stimulation and proper se- lective population of neuropathic pain is moderate for long-term relief.
28.11.13
Implantable Intrathecal Drug Delivery Systems
There is moderate evidence indicating the long-term effectiveness of intrathecal infusion systems.
28.12
Critical Evaluation
Semi-invasive and interventional procedures for the treatment of painful spinal disorders have become in- creasingly popular since the 1990s. This is due not only to the better understanding of the pathophysiology of spinal pain and the ability to specifically identify and target painful structures with percutaneous proce- dures, but also because of advances in imaging technol- ogy. Similar to developments in other areas of medi- cine, there is an increasing demand for less invasive, outpatient procedures to alleviate a patient’s pain.
While many of these procedures allow a patient to re- turn to full function with minimal downtime, future re- search needs to improve on implementation of ran- domized controlled trials to determine useful from useless procedures, and to improve on the therapeutic effects of injectable pharmaceutical agents and the de- livery methods. Several international societies work on the standardization of these procedures, but much work in this area remains to be done [2]. If the appro- priate research studies continue to support the effec- tiveness of interventional spinal procedures, their im- portance as intermediate therapy between traditional non-surgical and surgical treatment for spinal disor- ders will likely increase.
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