11.2.4\ Microdiscectomy

11.2.4.1\ Discussion

Microdiscectomy is a minimally invasive technique for treating symptomatic disc herniations and consists of curettage of disc material under surgical microscope visualization typically done with a midline or paramedian approach (Fig. 11.11). Portions of ligamentum flavum are often removed (flavectomy) in order to provide adequate access to the disc and to contribute to decompression of the spinal canal (Fig. 11.12). The posterior elements otherwise remain intact,

a b

thereby preserving stability of the spinal column. Clinical success of microdiscectomy is over 90% at 6 months and over 80% at 10 years. Complications are uncommon and include infection,­ dural tear, nerve root injury, and residual or re-herniation of disc fragments. Imaging is important for evaluating potential complications. Occasionally, hemostatic agents placed near the disc space can resemble a residual or re-herniated disc fragment, except these materials tend to have lower signal on T1-weighted and T2-weighted MRI sequences than does disc material (Fig. 11.13).

Fig. 11.11  Microdiscectomy. Preoperative sagittal T2-weighted MRI (a) shows a disc herniation at L5–S1 (arrow). Sagittal T2-weighted MRI (b) obtained after

microdiscectomy shows interval resection of the herniated disc material, without significant alteration to the surrounding structures