RT Journal Article SR Electronic T1 Minimally invasive surgery for lumbar synovial cysts with coexisting degenerative spondylolisthesis JF International Journal of Spine Surgery JO Int J Spine Surg FD International Society for the Advancement of Spine Surgery SP 37 DO 10.14444/3037 VO 10 A1 Daniel R. Denis A1 Daniel Hirt A1 Saumya Shah A1 Daniel C. Lu A1 Langston T. Holly YR 2016 UL http://ijssurgery.com//content/10/37.abstract AB Background About one third of lumbar synovial cysts are associated with degenerative spondylolisthesis. Segmental instability is thought to contribute to the pathogenesis and recurrence of synovial cysts and lumbar fusion has been advocated as a treatment of choice in the presence of spondylolisthesis. In patients with spondylolisthesis, minimally invasive resection of lumbar synovial cysts, without fusion, could minimize surgically induced segmental instability while providing good pain relief.Methods Clinical and radiological outcomes of lumbar synovial cyst patients with and without spondylolisthesis were retrospectively compared. Pain outcomes were assessed with modified Macnab criteria.Results Fifty-three patients (18 with grade 1 spondylolisthesis) underwent minimally invasive synovial cyst resection and all had either excellent or good pain outcome at ≤ 8 post- operative weeks (P = 1.000, n = 53). At > 8 post-operative weeks (mean (SD) follow-up of 200 (175) weeks), excellent or good outcomes were noted in 89% of patients without spondylolisthesis and in 75% of patients with spondylolisthesis (P = 0.425, n = 40). Four patients developed a new grade 1 spondylolisthesis at a mean follow-up of 2.6 ± 2.1 years. Nine patients were assessed for spondylolisthesis measurements at 1.2 ± 1.3 years of follow up and no significant difference was observed (5 ± 0 vs 5 ± 1 mm; P = 0.791). Two patients without spondylolisthesis and none of the patients with spondylolisthesis had a synovial cyst recurrence.Conclusion Patients with concomitant lumbar degenerative spondylolisthesis and synovial cyst can have good short- and long-term clinical outcomes with minimally invasive surgery without fusion. Post-operative segmental instability does not appear to be significant in patients with spondylolisthesis.All patients included in this article signed an informed consent for the use of their medical information for research.