Background The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and instrumented posterior lumbar interbody fusion (iPLIF) in patients with lumbar disc hiation and Modic endplate changes.Our hypothesis was that iPLIF could provide better outcome for patients with refractory lumbar disc hiation and Modic changes (LDH-MC).Methods Ninety-one patients with single-segment LDH-MC were recruited.All patients experienced low back pain as well as radicular leg pain,and low back pain was more severe than leg pain.Forty-seven patients were treated with discectomy and 44 were treated with iPLIE The outcomes of both low back pain and radicular leg pain using visual analogue scale (VAS) as well as the clinical outcome related to low back pain using Japanese Orthopaedic Association (JOA) score were assessed before and 18 months after surgery,respectively.Results Both low back and leg pain were significantly improved 18 months after simple discectomy and iPLIE Compared to patients undergoing simple discectomy,low back pain was significantly reduced in patients undergoing iPLIE but there was no significant difference in leg pain between two groups.Solid fusion was achieved in all patients who underwent iPLIF.Conclusions In patients with LDH-MC,iPLIF can yield significantly superior outcome on the relief of low back pain compared to simple discectomy.Simple discectomy can relieve radicular leg pain as efficient as iPLIE Accordingly,iPLIF seems to be a reliable treatment for patients with LDH-MC and predominant low back pain.