Background: Intradiscal platelet-rich plasma (PRP) has emerging evidence for the treatment of discogenic low back pain. However, procedural access becomes technically challenging at the L5-S1 level in the presence of severe disc collapse, steep lumbosacral lordosis, or high iliac crest morphology, which may preclude standard posterolateral or transforaminal trajectories.

Case Report: A 42-year-old man with chronic discogenic low back pain demonstrated severe L5-S1 degeneration (modified Pfirrmann grade 6) with approximately 3-mm residual disc height, rendering conventional intradiscal access unsafe or impossible. A modified computed tomography-guided interlaminar trajectory passing briefly through the thecal sac was used to achieve intradiscal access. Two milliliters of ultra-high cell-count PRP was injected into the disc nucleus. During controlled needle withdrawal, small aliquots of PRP were deposited at the dural puncture sites to biologically reinforce the needle tract.

Conclusions: Our case describes a technically feasible intradiscal PRP delivery route for end-stage L5-S1 disc collapse when all conventional access methods are obstructed. No postprocedure cerebrospinal fluid leak symptoms or neurological complications occurred, and early symptomatic improvement was reported. Further investigation is warranted to evaluate safety, reproducibility, and broader clinical applicability.

KEYWORDS: Case report, PRP, disc collapse, intradiscal, transdural