Radiological analysis of upper lumbar disc herniation and ... - Springer

L3–4 disc herniation patients matched much more closely those of L4–5 and L5–S1 disc herniation patients, and therefore they proposed that future studies of upper versus lower disc herniation should include L3–L4 herniation in the lower category [20]. Because of the rarity of ULD, its pathogenesis has not been thoroughly studied. ................
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