Radicular nerve root pain or radiculitis is a common clinical problem caused by a pinched nerve or radiculopathy.¹ The pain radiates along the sensory distribution of a nerve (dermatome)  due to inflammation or irritation of the nerve root at its connection to the spinal column.²

The sciatica is a term used to describe the pain that radiates along the sensory distribution of the sciatic nerve, affecting the lower back through the hips and buttocks and down each leg. The most frequent cause of sciatica is the compression of the nerve(s) which is resulted by a disc prolapse or stenosis.³

About 50% of the patients with sciatica report a decline in the quality of their lives and ability to function.^4,5 Intervertebral disc prolapse is the major cause of lumbosacral radiculopathy, subsequently about 10% to 15% of these patients require surgery. ^6,7 Overall, the majority of the patients with lumbosacral radiculopathy recover with non-surgical care.The conservative care includes a constellation of bed rest, medications, lumbar belts, and physiotherapy. ^8-9

The nerve root compression stimulates inflammatory processes, forming a rationale for the use of epidural corticosteroids to inhibit inflammation and ease the pain.¹⁰ In the past, epidural steroid injections have been used as an adjunctive treatment in patients with sciatica.¹¹ Since the early reports, success rates ranging from 20% to 100% with an average success rate of 67% have been documented.¹² A transforaminal epidural injection is the latest type of epidural steroid injection which involves injecting corticosteroids into the epidural space through the bony opening of the exiting nerve root, known as the foramen. It causes numbness of the nerve, alleviating the pain and reducing inflammation.¹³ However, the efficacy of steroid injection was reported to last for less than 3 months.

Despite the number of studies conducted on the topic, the efficacy of foraminal corticosteroid injections for the treatment of radicular pain remains controversial. The inconsistency between the studies on the efficacy of the foraminal injection has prompted this research where we aimed to evaluate the clinical outcome and efficacy of foraminal steroid injection in relieving chronic radicular pain in our population.

A cross-sectional observational study was conducted at the Orthopedic and Spine Unit, Hayatabad Medical Complex, Peshawar from February, 2023 to January, 2024 for a period of 1 year. Upon the issuance of ethical approval from the institutional review board, a total of  44 adult patients presenting with lumbar radiculopathy were enrolled. Informed written consent was obtained from all patients. The inclusion criteria for enrollment of patients was; consenting individuals with lower back pain due to a nerve root compression, radiating to one or both legs. Those presenting with lumbar intervertebral disc prolapse were also included in the study. Patients with known contraindications for epidural steroid injections, current infection, coagulopathy or malignancy, history of lumbar steroid injection or spinal surgery, nervous system deficits were excluded from the study. After taking complete clinical history and proper neurological examination, pre-procedural assessment, patients were prepared for the foraminal epidural steroid injection. Procedure of the treatment, any side effects or complications were disclosed to the patients.

Administration of Foraminal Epidural Steroid Injection

A double-needle paramedian technique was used to access the intervertebral foramen of L3–L4, L4–L5, and L5–S1.¹⁴ After administering a local anesthesia; a 20-gauge spinal needle of 3.5 inch was inserted to the ipsilateral transverse process, and then relayed 1 cm anteroinferiorly. A curved 25-gauge spinal needle of 6-inch was proceeded through the 20-gauge introducer needle into the safe-triangle. Proper needle placement was confirmed by the anteroposterior and lateral fluoroscopic projections. With the lateral view, the needle was positioned just below the pedicle along the ventral aspect of the intervertebral foramen. With the anteroposterior view, the needle was placed just beneath the midportion of the corresponding pedicle.

Once the needle was accurately placed, 1 ml of contrast medium was administered and the results of the epidurogram and pain response were recorded. Once enough flow of contrast to the target area was recorded and no blood or cerebrospinal fluid was observed, a total of one and a half milliliter betamethasone acetate in addition to a 2% xylocaine solution was inoculated. The patient was advised to stay in supine position for about 30 minutes to 40 minutes, postoperatively.

The patient’s vitals were monitored throughout the procedure and thereafter for half an hour. Blood glucose levels were monitored 24 hours after the procedure and all the patients were screened thereafter for any major or minor complications. Patients were followed up on the 14th day, 1-month, 3-months and 6 months of the procedure for documentation of pain, patient satisfaction and side effects of the injections.

Clinical outcome was quantified using a patient satisfaction scale, a Roland-Morris low back pain questionnaire which evaluated the improvement rate, a measurement of finger-to floor distance with the patient in fully tolerated hip flexion and a visual numeric pain scale.^{12, 15-16}

A successful treatment outcome was defined as a patient satisfaction score of 2 (good) or 3 (very good), improvement on the Roland-Morris score of 5 or higher, and pain reduction of more than 50% 1 year post treatment.

A total of 44 patients were included in the study with a mean age ± SD of 37.56 ± 10.36 years (age range = 18-50 years). There were 20 (45.45%) male participants and 24 (54.5%) female participants in the study.

A total of 39 out of 44 i.e. 88.6% patients responded to the treatment and showed promising improvement. No post procedural complications such as infection, leakage, bleeding, headache were observed among patients.

At the end of the study period of 18 months, the patient satisfaction score had increased from 0.7 ± 0.5 to 3.1 ± 0.7, the mean Roland-Morris score was increased from 7.8 ± 1.4 to 24.3 ± 1.6, the visual numeric pain decreased from 9.7 ± 1.5 to 2.3 ± 0.8, and the finger-to-floor distance reduced from 65.6 ± 1.7 cm to 18.6 ± 1.3 cm. In the present study, about 88.6% of the participants were successfully treated with a satisfying clinical outcome, with the greatest improvement within 6-8 weeks of treatment. 

Table 1. Clinical Outcome of Patients Treated with Foraminal Steroid Injection

In lumbar radiculopathy which is refractory to all conservative treatment modalities, surgical intervention is a well-established and acceptable procedure to alleviate the discomfort due to the compression of the nerve. ¹⁷ However, the spinal surgery may precipitate high cost to the patient’s family and constitutes substantial risks to the patient. With this modified corticosteroid injection technique and with the help of the technically advanced imaging tools, an inflamed and irritated nerve root can be treated with no serious adverse effects. ^18,20

In the present study, we reported a successful clinical outcome of 88.6% i.e. 39 out of 44 patients showed improvement after the administration of foraminal steroid injection to alleviate the pain caused by the radiculopathy. This finding is in line with a study conducted by Yang SC et al., who reported that 73.7% of the patients in their study showed improvement upon administration of the transforaminal epidural steroid injection.²¹ However, Ghaly RF et al., reported that transforaminal epidural steroid injection resulted in further neurological injury in a patient presenting with severe radiculopathy. ²² Ghaly RF suggested that transforaminal epidural steroid injection should be avoided when there is evident worsening severe neurologic symptoms.

Previously, it was observed that the success rates for the lumbar epidural spinal shots for relieving pain ranges between 0% to 70% with affect lasting for less than 3 months or so.^{23, 24}The disparity between the current findings and the past studies can be attributed to the advancement in the technology leading to more accurate placement of the needle. Directly injecting the corticosteroid to the exact target nerve root using the double-needle parmedian transforaminal approach combined with the consistent physiotherapy and therapy may help in achieving greater patient satisfaction with greater pain free duration.

A better patient satisfaction and clinical outcome of transforaminal epidural steroid injection can be achieved by focusing on the following main factors: the precise administration of the corticosteroid and xylocaine injection, the nerve membrane stabilizing properties of both the steroid and xylocaine, the “washout” effect of the medication, minimizing the local effects of the inflammatory mediators including interleukin-1, tumor necrosis factor, and phospholipase A2, and finally the corticosteroid acting as a potent anti-inflammatory. ^25-27

For past few decades, lumbosacral pain has been dealt by administrating the foraminal epidural steroid shots. Nevertheless, there have been very limited studies conducting the controlled trials to determine the effectiveness of transforaminal epidural steroid injections for the treatment of lumbar radiculopathy or nerve compression among patients presenting with chronic nerve root impingement or stenosis. Further research is needed to evaluate the efficacy of this treatment modality and the factors affecting the clinical outcome.

We reported a good clinical outcome with the majority of the patients showing significant improvement after the administration of foraminal epidural steroid injection for relieving the radicular pain cause by a nerve root compression at lumbosacral level of spine. It is advised to conduct further research on this topic to reach a global consensus upon the efficacy of this treatment.

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