Rapid Spontaneous Resolution of Lumbar Intraspinal Facet Cyst after Lateral Lumbar Interbody Fusion

INTRODUCTION: Intraspinal facet cysts resistant to conservative treatment are treated surgically. Surgical treatment was generally resection and decompression, but complications of dural tear and recurrence sometimes occurred. We present good clinical results and rapid spontaneous resolution following treatment of five cases of lumbar intraspinal facet cyst after lateral lumbar interbody fusion (LLIF). METHODS: Multicenter series of five cases of lumbar intraspinal facet cyst with segmental instability treated with LLIF. The cross-sectional area (CSA) of the thecal sac and facet cyst on T2-weighted axial magnetic resonance imaging and the distance of facet joint (FJ) gap on axial computed tomography were measured preoperatively and postoperatively. Patient data and clinical and radiographic results were described. RESULTS: Of five patients, one was male and four were female, with an average age of 72.6 (61-76) years. The mean preoperative CSA of facet cyst was 40.09 mm(2). In all cases, intraspinal facet cyst resolved within two weeks after LLIF and good clinical results were obtained. The mean CSA of the thecal sac increased from 64.18 mm(2) preoperatively to 95.72 mm(2) postoperatively. The mean distance of FJ gap increased from 0.8 (0-1.5) mm preoperatively to 3.1 (0.5-6.0) mm postoperatively. CONCLUSIONS: LLIF may be indicated for intraspinal facet cysts with segmental instability.