Transforaminal Injection

Transforaminal injections are a treatment option that offers a ray of hope to many people suffering from back, neck, and spinal pain. This method aims to deliver the medication as close as possible to the source of pain and to calm the inflammation around the nerve root. This application, which can yield very effective results, is important in understanding the complex structure of the spine and focusing on the correct spot. It can be compared to looking through a small doorway and applying the medication directly on the problem inside. In this way, a “precision strike” is made to the area where the problem occurs.

What Is a Transforaminal Injection and How Does It Work?

A transforaminal injection is a treatment method that aims to reach the nerve root through the small bony openings called “foramina” located on the sides of the spinal column. These foramina can be thought of as narrow passageways through which the nerves, akin to electrical cables, exit the spine and distribute to different parts of the body. When these nerves become compressed or irritated while passing through the narrow tunnel, pain results. A transforaminal injection provides direct anti‑inflammatory medication (usually a corticosteroid) and sometimes a local anesthetic to the area of compression.

This method can be compared to clearing the weeds around a specific tree in a garden instead of spraying the entire garden with herbicide. By applying the medication directly to the problematic area, unnecessary exposure of the entire “garden” is avoided, thereby reducing side effects and enhancing the targeted effectiveness of the treatment. The local anesthetic offers immediate, short‑term relief from pain, while the corticosteroid reduces inflammation in the area, providing more lasting improvement.

The working mechanism of a transforaminal injection is based on “calming the inflamed nerve root.” Sinus inflammation around the nerve root makes the nerve as tender and painful as a swollen finger. Once the inflammation decreases, the pressure and sensitivity on the nerve also decrease, thus alleviating the pain. This relief may be noticed immediately in some cases and within a few days in others. During the procedure, the spinal canal and nerve roots are visualized with X‑ray (fluoroscopy) to ensure that the injection is administered in the exact location. This is like “tracking the target through a scope”; it increases the accuracy and reduces potential risks.

Why Are Transforaminal Injections Used for Pain Management?

Many methods are tried in pain management: physical therapy, medications, and surgical interventions. One of the main reasons for choosing transforaminal injections is that they target the very source of the pain. For example, in cases of lumbar disc herniation, the disc material may compress the nerve root, triggering inflammatory processes. This compression and inflammation result in pain signals radiating along the nerve. Transforaminal injections work by applying a corticosteroid to the inflamed, sensitized nerve root to quell the swelling.

The goal in pain treatment is not only to relieve pain but also to facilitate the patient’s return to daily life. Transforaminal injections are extremely effective in this regard; if the source of pain is clearly identified, the injection is performed in a targeted manner. It is akin to sealing a leak directly at the source on a roof, so you don’t have to repaint the entire house or undertake major repairs.

Furthermore, one advantage of transforaminal injections is that they are far less invasive compared to surgery. Considering the risks of anesthesia, long recovery periods, and possible complications associated with surgery, injections are often used as a first‑line or intermediary treatment. Severe back pain, sciatica, and symptoms of cervical disc herniation can significantly diminish a patient’s quality of life. Oral painkillers may sometimes be insufficient, and the systemic side effects of some medications can be troublesome. In contrast, transforaminal injections offer a “spot‑on” solution to the problem with minimal systemic side effects. This method helps the patient return quickly to daily activities and is sometimes combined with physical therapy or exercise to further enhance its effectiveness.

How Is a Transforaminal Injection Applied to the Spine?

You can imagine this procedure as a delicate maneuver. Using a thin and long needle through the small openings (foramina) in the spine, the needle is guided right next to the nerve. As the needle travels through the unseen path between bones and tissues, an X‑ray imaging device called fluoroscopy is used. It is similar to observing the inside of a machine with a camera while trying to repair a faulty part… Every step is taken with care to ensure that the target is not missed.

The procedure generally begins with the patient lying in a supine or sometimes a slightly lateral position. The skin is cleaned with an appropriate antiseptic solution and sterile conditions are ensured. In some cases, local anesthetic is applied to the injection area to reduce discomfort during the procedure. The needle is then advanced in millimetric increments. As the needle tip is directed into the foramen, the physician continuously monitors the fluoroscopy screen. Once the needle is confirmed to be in the correct position, a contrast agent is typically injected. The contrast agent acts like a red line on a roadmap, showing where the medication will spread.

After confirming the correct position, a mixture containing corticosteroid and local anesthetic is slowly injected. This cocktail of medications envelops the nerve root to control inflammation and soothe pain signals. The procedure generally lasts about 10–15 minutes, though the entire process, including preparation and post‑procedure observation, may take longer. To ensure patient comfort, a calm environment is maintained throughout the procedure, minimizing stress during the injection.

Given the sensitive structures of the spine, every detail is critical. Variables such as the needle’s gauge, angle, and the amount of medication are precisely calculated. The ultimate goal is to achieve maximum effect with minimal intervention. After the procedure, a slight pain, burning, or pressure sensation in the injection area may be felt for a few hours, but this typically subsides quickly.

What Medications Are Used in Transforaminal Injections?

In transforaminal injections, two main categories of medications are commonly used: corticosteroids and local anesthetics. Corticosteroids are potent agents in suppressing inflammatory processes in the body. These drugs can be thought of like a fire extinguisher: applied directly where there is inflammation. Common corticosteroid derivatives used include methylprednisolone, triamcinolone, betamethasone, or dexamethasone. Each has a different duration of action, dissolution, and distribution in the tissue. Some act more quickly, while others provide longer‑term relief.

Local anesthetics temporarily block pain signal transmission from the injection area. This can be compared to creating a brief interruption in an electrical circuit; the pain signal from the nerve to the brain is temporarily blocked. Lidocaine or bupivacaine are typically mixed with the corticosteroid, thus providing both short‑term pain control and increasing patient comfort in the first hours after the procedure.

The use of a contrast agent is also important. To clearly visualize the injection area under fluoroscopy and verify that the medication is spreading to the correct area, iodinated contrast agents are usually preferred. These contrasts can be thought of like a dye that highlights the color of water flowing through a pipe. The aim is to increase the safety and accuracy of the injection.

The choice of corticosteroid depends on the physician’s experience and the patient’s condition. For example, a long‑acting steroid may be chosen to provide more lasting relief, or a short‑acting steroid may be used to achieve a quicker but temporary effect. In this regard, factors such as the patient’s overall health, susceptibility to side effects, and the presence of chronic diseases like diabetes are important considerations.

Who Can Benefit from Transforaminal Injections?

Spinal pain can result from a variety of causes. Prolonged sitting at a desk, poor posture, heavy lifting, or genetic predisposition can lead to the degeneration of spinal discs over time, resulting in nerve root compression. Transforaminal injections are particularly beneficial for individuals experiencing pain due to nerve root inflammation or compression.

People suffering from severe pain radiating to the legs or arms due to lumbar (herniated disc) or cervical disc herniation can benefit from this procedure. Similarly, in cases of spinal stenosis or narrowing of the foramina that compresses the nerve root and causes pain to radiate to the buttocks, legs, or back, transforaminal injections help reduce discomfort and improve mobility.

Sometimes patients do not obtain sufficient relief from oral painkillers or may suffer from the side effects of these medications. In such cases, delivering the medication directly to the target area via injection prevents unnecessary systemic exposure to high doses of medication. Additionally, transforaminal injections can be an effective option for individuals who have had previous back or neck surgery and continue to experience pain, but do not wish to undergo further surgery.

The duration of pain is also an important factor. In patients with acute pain, the effect of the injection may be more pronounced and rapid. However, even in patients with chronic pain, this method serves as an important step in pain management. Still, every patient is unique, and the decision for injection should be supported by a detailed examination and imaging findings.

What Complaints Are Treated with Transforaminal Injections?

Transforaminal injections are primarily used to treat “radicular pain,” which results from inflammation or compression of the nerve roots exiting the spinal cord. They are preferred for pain originating in the lumbar (lower back), cervical (neck), and, less commonly, thoracic (upper back) regions. Conditions such as lumbar disc herniation, cervical disc herniation, spinal stenosis, adhesions around the spinal cord, and foraminal stenosis are among the most common disorders treated with transforaminal injections.

For example, lumbar disc herniation is a familiar diagnosis for many: the disc material protrudes slightly between the vertebrae, compressing the nerve root and causing pain that radiates down the leg, accompanied by numbness, tingling, and weakness. Transforaminal injections come into play by applying a corticosteroid to the compressed area to “extinguish the fire.” This also effectively relieves pain in the hip and leg areas.

Spinal stenosis, on the other hand, is a process in which the narrowing of the spinal canal restricts the movement of neural tissues. In this condition, the narrowed area forces the nerves to pass through a tight tunnel; over time, the nerve root becomes inflamed and pain, especially during walking, increases. Transforaminal injections target the area where the nerve root is most compromised, aiming to reduce this irritation.

Furthermore, this method is an effective tool in relieving pain caused by scar tissue formation after surgery or in cases of failed back surgery syndrome. In these situations, when post‑surgical tissue puts pressure on the nerve root, a transforaminal injection provides a localized solution. All these various conditions are evaluated based on the severity and source of the spinal pain to determine the suitability of the injection.

How Do Transforaminal Injections Differ from Other Epidural Injections?

Epidural injections fundamentally refer to the administration of medication into the epidural space surrounding the spinal cord. However, the approach used significantly affects how well the medication reaches the target area. The most common types of epidural injections include interlaminar, caudal, and transforaminal approaches.

• An interlaminar injection is administered through the space between the laminae at the back of the vertebrae, reaching the epidural space. The medication distribution is broader, but it may not always precisely target the nerve root.
• A caudal injection is given through the sacral hiatus at the lower end of the back, and the medication can spread over a wide area, though it may not focus exactly at the nerve root level.
• A transforaminal injection is directed through the lateral opening called the foramen, targeting the nerve root where it exits. It offers a “precision strike” to the area most affected by compression and inflammation.

This difference can be compared to a traffic accident on a highway. An interlaminar or caudal injection is like entering a general congested area; it may partially solve the traffic problem, but it might not reach the exact lane where the accident occurred. A transforaminal injection, on the other hand, is like an ambulance going directly to the accident scene—right at the heart of the problem. If there is a “fire” at the nerve root, this is the most effective method to extinguish it.

If the source of the patient’s complaint is confined to a single nerve root, the transforaminal approach generally yields more successful results because the majority of the medication is concentrated in that area. Although interlaminar injections are also effective and sometimes preferred in cases of widespread or bilateral pain, transforaminal injections stand out in unilateral, nerve‑root‑focused pain. Studies have shown that in the short and medium term, this method reduces the need for pain medications and increases physical activity in many patients.

How Effective Are Transforaminal Injections as a Pain Reliever?

Although the effectiveness of transforaminal injections varies from person to person, many scientific studies agree that this method is highly successful in relieving nerve‑related pain in the back, neck, and associated limbs. The reduction in pain after the injection allows patients to more easily resume daily activities. In cases such as disc herniation or nerve root compression, patients who have difficulty walking due to pain have been shown to significantly increase their walking distance after the injection.

The degree of pain relief often depends on the severity of the pain before the injection, the patient’s overall health, and the duration of the pain. In cases of acute (recent onset) pain, injections generally produce a faster response, while in chronic pain patients a slightly longer wait may be necessary to see the full effect. Nonetheless, many cases of chronic pain have also shown significant relief following the procedure.

In terms of duration, some patients experience significant relief for several weeks to a few months, while others may have near‑pain‑free or much milder pain for up to a year. If the effect of a single injection is insufficient, repeat injections can be scheduled. These repeats are not necessarily done “every month” but are adjusted based on the patient’s response, the degree of pain reduction, and possibly in conjunction with supportive methods such as physical therapy.

Another factor that increases success is the precision of the procedure. When performed under fluoroscopy guidance, the needle is accurately directed to the correct nerve root, ensuring that the medication reaches its target. Thus, when the source of the pain is definitively identified and the injection is administered with proper technique, transforaminal injections become an important component of pain management for many patients.

What Are the Potential Side Effects of Transforaminal Injections?

As with any medical procedure, transforaminal injections have potential side effects and risks, though most are mild and temporary. After the procedure, some patients may experience pain or a sensation of pressure in the injection area for a few hours. Some patients might notice temporary numbness or weakness near the injection site, which is caused by the local anesthetic’s temporary blockade of nerve conduction and usually resolves within a few hours.

Side effects related to corticosteroids can include short‑term facial flushing, mild edema, insomnia, or palpitations. These effects can be viewed as a transient bodily response to steroids and typically subside within 1–2 days. Diabetic patients may experience temporary fluctuations in blood sugar levels; therefore, it is recommended that individuals with diabetes closely monitor their blood sugar after the procedure.

Rarely, serious complications may occur. These include infection (such as epidural abscess or meningitis), bleeding, nerve injury, accidental injection of air into the epidural space (air embolism), or inadvertent injection into a blood vessel. However, these complications are very rare, and when the injection is performed under sterile conditions by experienced practitioners using appropriate imaging guidance, the risk is minimized. In cervical transforaminal injections, there have been rare reports of significant vascular injuries. Therefore, the use of contrast agents and careful verification of the needle tip position under fluoroscopy are of utmost importance during the procedure.

How Long Does the Pain-Relieving Effect Last After a Transforaminal Injection?

The duration of the pain-relieving effect after a transforaminal injection depends on individual factors, the cause of the pain, and the type of corticosteroid used in the procedure. Some patients report that the local anesthetic’s effect reduces the pain to almost zero within the first few hours. However, this initial effect is typically short-lived since the local anesthetic’s maximum impact lasts only a few hours.

Once the corticosteroid begins to work, a more sustained relief usually starts within 2–3 days or sometimes up to a week. This is due to the gradual suppression of the inflammatory process in the body. For example, a person with a lumbar disc herniation and severe leg pain might report, “My walking distance improved significantly and my pain decreased by about 70%,” 3–5 days after the injection. This relief can last for weeks or even months.

Over time, there is a potential for the pain to return. In some patients, pain remains at minimal levels for months, while in others it may become significant again after a few weeks. This may be due to the underlying structural issues in the spine not being fully resolved or due to lifestyle factors. For instance, returning to strenuous physical activity too early, before complete recovery, can re-aggravate the back. A treatment protocol supported by physical therapy and exercises can help prolong the pain-relieving effect of the injection.

If the pain recurs and becomes severe again, a repeat injection may be considered under the supervision of a doctor. Repeat injections are generally scheduled not monthly, but at intervals of several months or, if necessary, about once a year. Throughout this process, the important goal is to maintain long-term control of the pain source and maximize the patient’s quality of life.

What Can Be Expected During the Recovery Process After a Transforaminal Injection?

After the procedure, patients are generally advised to remain under observation in the hospital or clinic for the first few hours. This period allows for early detection and management of any immediate side effects. It is normal to experience a mild pain or burning sensation, or even a brief “electric shock” feeling at the injection site. For example, you may feel a slight ache radiating down your leg or a mild burning at the needle entry point, but these sensations typically pass quickly.

It is advisable to avoid heavy lifting, strenuous exercise, or prolonged sitting for the first 24–48 hours. Think of this period like the first days of nurturing a newly planted seedling; the better you care for it, the stronger its roots will grow and the more fruitful it will be in the long run. Similarly, the spine needs some rest after receiving the new treatment. However, complete immobility is not recommended. Light walking or gentle exercises can support circulation and positively influence the recovery process.

The course of recovery varies from person to person. Some may experience significant relief by the next day, while others might need up to a week to see the full effect. During this period, even if some mild pain persists, the main goal of significantly reducing severe pain is usually achieved. Individuals with chronic conditions such as diabetes should monitor their blood sugar levels more closely after the procedure, as corticosteroids can temporarily elevate blood sugar.

If, after the injection, there is a sudden onset of severe headache, fever, increased redness at the injection site, or marked neurological symptoms (such as leg weakness or loss of coordination), prompt medical evaluation is necessary. These may be signs of serious complications. However, overall, the post‑injection period is generally uneventful with simple pain management and mild rest leading to recovery.

Are There Any Risks or Complications Associated with Transforaminal Injections?

Although transforaminal injections are much less risky than surgical interventions, they are not entirely without risk. As with any procedure performed near the spine, caution and precision are paramount. When the needle is directed under fluoroscopy guidance, risks are minimized; however, there remains a theoretical possibility of vascular injury, nerve damage, or infection.

• Infection: Although the risk is very low when the injection is performed under sterile conditions, severe infections such as epidural abscess or meningitis have been rarely reported in the literature.
• Bleeding: Patients taking blood thinners or those with bleeding disorders have a higher risk of developing a hematoma, which could put pressure on the nerve root or spinal canal.
• Intravascular Injection: If the needle inadvertently enters a blood vessel, the medication can enter the systemic circulation. This undesirable event is largely prevented with proper technique.
• Nerve Injury: Direct contact of the needle with the nerve root or complications in its vicinity may result in nerve damage, which can manifest as increased pain, numbness, or, rarely, muscle weakness.
• Air Embolism: Although very rare, the accidental injection of air during the procedure can lead to an air embolism.

Although these complications might sound alarming, their incidence is extremely low when the procedure is performed by experienced specialists using appropriate equipment and imaging guidance. Large‑scale studies have reported serious adverse effects or complication rates of less than 1%. Nonetheless, given the critical nature of the spine, even a low probability of complications is important.

How Can You Prepare for a Transforaminal Injection Appointment?

Preparation before a transforaminal injection is important to ensure that the procedure is safe and comfortable. Although the recommended steps are generally simple and do not vary significantly, they may change depending on individual health conditions. Generally, the following points are emphasized:

• Medication Assessment: If you regularly use blood thinners (such as aspirin, clopidogrel, warfarin, or heparin derivatives), it is important to inform your doctor before the procedure. If necessary, short‑term adjustments in dosage or usage may be made.
• Allergy Information: Individuals with a history of allergy to contrast agents or corticosteroids should notify their doctor in advance. Allergic reactions can range from skin rashes to anaphylaxis.
• Nutrition and Hydration: Fasting for an extended period is generally not required before the procedure; however, if sedation is used, you may be asked to fast until a specified time as directed by your doctor. Adequate water intake supports overall body function and helps maintain healthy blood vessels.
• Comfortable Clothing: Choose loose, easily removable clothing to allow easy access to the back and neck regions.
• Accompaniment: On the day of the injection, especially for procedures in the lumbar area, you might experience temporary leg weakness or numbness afterward. Having someone accompany you for safe transportation is advisable, as driving might not be safe.
• Pre‑Procedure Briefing: For those with high levels of anxiety before the procedure, sedatives are generally not recommended; however, in special cases, a low dose of sedation may be administered. In any case, it is important to discuss your concerns, pain threshold, and overall health during the doctor’s evaluation.

Prof. Dr. Özgür KILIÇKESMEZ

Prof. Dr. Özgür Kılıçkesmez graduated from Cerrahpaşa Medical Faculty in 1997. He completed his specialization at Istanbul Education and Research Hospital. He received training in interventional radiology and oncology in London. He founded the interventional radiology department at Istanbul Çam and Sakura City Hospital and became a professor in 2020. He holds many international awards and certificates, has over 150 scientific publications, and has been cited more than 1500 times. He is currently working at Medicana Ataköy Hospital.