The association between lumbosacral radiculopathy and the ipsilateral gluteal trigger point has been demonstrated in 74% of previous studies in patients with chronic low back pain. It has also been found to be associated with lumbosacral radiculopathy, central sensitization and myofascial pain in previous studies.

From these data, it can be hypothesized that the presence of a myofascial trigger point in the relevant muscle segment may alter the efficacy of the transforaminal epidural steroid injection (TFESI) procedure used in the treatment of lumbosacral radiculopathy. We could not find any study on this subject in the literature. Although the most accurate level for the TFESI procedure is determined according to the patient's examination and imaging findings, patients may not benefit from the procedure sufficiently due to the trigger points on the same side as the radicular pain before the procedure. Another hypothesis is that active trigger points will transform into latent or normal tissue after the TFESI procedure and patients will benefit significantly. This assumption will provide insight into the possible underlying mechanism in some patients who do not benefit from the TFESI procedure. If the active trigger points become latent or there is a significant change in the pressure pain threshold after the TFESI procedure, the formation mechanism of the trigger points will be understood.

TFESI is one of the procedures routinely applied to patients diagnosed with lumbosacral radiculopathy in investigator's clinic. Among the patients who are planned to undergo TFESI procedure, those who are suitable for our study will be selected. Data such as demographic characteristics, height, weight, which leg the pain is reflected in, additional diseases, medications, the stage of the disc herniation, pressure on which nerve root, presence and number of active trigger points, muscles will be recorded before the procedure. Numerical Rating Scale (NRS), Short Form-12, Central Sensitivity Inventory (CSI), Doulour Neuropathic 4 (DN4), 6-point Likert Scale, Jenkins Sleep Scale, Istanbul Low Back Pain Disability Index, Pressure Pain Threshold (active trigger points will be evaluated with an algometer) will be applied to the patients before the procedure. The patients will be evaluated for the presence of active trigger points before the procedure and the patients will be divided into 2 groups as those with active trigger points and those without. The same procedure will be applied to both groups as planned before inclusion of the patients in the study, in the same way as the patients ineligible for the study. Patients will be re-evaluated with the scales and methods mentioned above at the 3rd week, 3rd and 6th months after the first procedure. TFESI procedure will be performed again in the 3rd week and 3rd month for the patients whose NRS values decrease less than 50 percent after the previous procedure.

Inclusion Criteria:

• Having low back pain for at least 3 months due to lumbosacral radiculopathy
• Root compression due to paracentral disc herniation at L4-L5 or L5-S1 levels in accordance with the patient's complaint and clinical findings in lumbar MRI imaging
• Being unresponsive to conservative treatment
• Volunteering to participate in the study and signing a consent form

Exclusion Criteria:

• History of surgery on the lumbar region/interventional procedure in the last 6 months
• Presence of additional musculoskeletal disease (such as lateral epicondylitis, tendinitis)
• Disease that may change the anatomical or physiological structure of the relevant regions (such as rheumatoid arthritis, osteoporosis)
• Presence of coagulopathy
• Presence of lumbar spinal stenosis
• Having a diagnosis of fibromyalgia
• Being pregnant or breastfeeding
• History of allergy to the injectables to be administered
• Having a diagnosis of mental, psychiatric or neurological disease that may complicate the application of the study.