BACKGROUND CONTEXT Lumbar laminectomy with fusion has been the most commonly performed operative treatment in lumbar stenosis with concomitant instability or deformity. Although this usually provides adequate decompression of the neural elements, it leaves only the transverse processes and a fraction of the facet joint as available bony surface for fusion, likely contributing to a reported pseudarthrosis rate of up to 35%. Sublaminar decompression “SLD,” a new lamina-preserving technique for lumbar spinal decompression, has potential advantages over conventional laminectomy; these include preserving the dorsal bony surface for fusion, minimizing dead space, and potentially decreasing incidental durotomies and epidural hematomas. Although a favorable clinical outcome has been reported, the adequacy of decompression compared to laminectomy has not been studied. PURPOSE The objective of this study is to radiographically evaluate the adequacy of decompression using SLD as compared to the more commonly done traditional laminectomy in a cadaveric spine model. STUDY DESIGN/SETTING Cadaveric. PATIENT SAMPLE Not applicable. OUTCOME MEASURES The extent of decompression of the cadaveric spines after either laminectomy or sublaminar decompression, assessed by CT and MRI. METHODS Ten cadaveric spines were randomized to two groups; either conventional laminectomy with medial facetectomy or SLD at L2-L5 performed by two senior fellowship trained spine surgeons. The adequacy of decompression at the central canal, lateral recesses, and foramina was measured using pre- and postoperative MRI and CT, then analyzed by two blinded observers according to a predefined protocol. Interrater reliability was calculated using the intraclass correlation coefficient (ICC). RESULTS There was no significant difference in preoperative parameters between the groups, except foramen height on CT (p=0.006). The interrater reliability was good to excellent for all but one measurement. At the disc level, MRI demonstrated that SLD resulted in improved AP diameter at the lateral recess (p CONCLUSIONS The novel “SLD” allows comparable or better decompression of the spinal canal compared to traditional laminectomy. In addition, preserving the posterior elements has several advantages: providing a larger fusion bed, minimizing dead space and potentially decreasing incidental durotomies in patients undergoing decompression and posterior lumbar fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.