Isolated Gluteal (Buttock) Pain Due to L2-3 Degenerative Disc Disease: A Case Report Highlighting Diagnostic Challenges and the Role of Spinal Injection in Guiding Management

High lumbar degenerative disc disease (DDD) is an uncommon cause of radiculopathy and may present with atypical clinical features, creating diagnostic uncertainty and delaying appropriate management. We report the case of a 48-year-old man who presented with chronic isolated right gluteal pain without lower limb symptoms or sciatic radiation. The initial differential diagnosis included sacroiliac joint dysfunction and piriformis syndrome. Lumbar imaging demonstrated advanced L2-3 degenerative disc disease with severe foraminal stenosis. Because of the unusual presentation, a selective L2-3 transforaminal epidural steroid injection was performed as a diagnostic and therapeutic procedure, resulting in marked temporary pain relief and confirming the symptomatic level. Following recurrence of symptoms, the patient underwent L2-3 transforaminal lumbar interbody fusion with decompression and instrumentation, with significant postoperative improvement. This case highlights that isolated buttock pain may represent an atypical manifestation of upper lumbar radiculopathy and emphasizes the value of targeted diagnostic injections in identifying the pain generator before definitive surgical treatment.