LAUSR

L facet cysts are an uncommon but problematic source of pain and neurologic dysfunction. Although a plethora of terminology has been used to describe cystic formations adjacent to facet joints, such as juxtafacet cysts, cystic malformations of the mobile spine, synovial cysts, and pseudocysts, for the purpose of this article we will refer to this pathology as “lumbar facet cysts.” It is well known that lumbar facet cysts are closely linked to facet degeneration. Kusakabe et al1 reviewed pathology specimens from 46 lumbar facet cysts, finding moderate to severe degenerative facet disease in all specimens and the size of the cyst positively associated with the degree of facet degeneration. Although strong associations have been found between degenerative spondylolisthesis and lumbar facet cysts, lumbar facet cysts can be commonly found without evidence of spondylolisthesis. Banning et al2 noted on review of 33 operatively treated lumbar facet cysts that 91% were associated with significant facet degeneration, whereas only 41% were associated with spondylolisthesis. Similar studies reviewing magnetic resonance imaging report only ∼32% to 54% of lumbar facet cysts are associated with spondylolisthesis.3–6 Furthermore, it is unclear whether instability is strongly correlated with lumbar facet cyst formation. Chugh et al7 were unable to associate increased incidence of lumbar facet cysts in patients with unstable degenerative spondylolisthesis, noting 10 lumbar facet cysts in 26 unstable spondylolistheses (> 3 mm change between flexion and extension views) and 18 lumbar facet cysts in 60 stable spondylolistheses (P> 0.05). It would appear to be erroneous to say that the presence of a lumbar facet cyst alone is a proxy of instability. Multiple case series of simple decompression and lumbar facet cyst resection have been published stating successful results. Campbell et al8 reported their experience with 158 decompressions for lumbar facet cysts, finding a low reoperation rate of <8% for patients with <15% lithesis on preoperative imaging, with lower reoperation rates associated with smaller facet cyst size. Metellus et al5 performed lumbar decompressions for lumbar facet cysts in 77 patients with spondylolisthesis found in 48% preoperatively and reported excellent or good outcomes in 97.4%, 1 revision fusion, and 1 recurrence at an average 45-month follow-up. Siu and Stoodley9 reported their experience of 46 facet cysts resections with decompressions, noting 7 patients progressing to grade 1 spondylolisthesis and 3 lumbar facet cyst recurrences during a 43-month average follow-up timeframe with 1 revision laminectomy. Van Dijke and colleagues reviewed 314 patients undergoing operative treatment of lumbar facet cysts, with 224 decompressions (35% with spondylolisthesis) compared with 90 decompression and fusion (63% with spondylolisthesis). After accounting for confounding variables, they were unable to demonstrate a difference in either persistence or recurrence of radiculopathy or back pain following these 2 procedures, although there was a higher reoperation rate in decompression versus fusion (8.5% vs. 2.2%, P=0.047). Subgroup analysis of the decompression cohort comparing those with and without spondylolisthesis found no difference in recurrence and/or persistence of either radiculopathy or back pain after the procedure.10 Conversely, several case series have been published suggesting inferior results from decompression alone for lumbar facet cysts. Xu and colleagues reported on 167 patients with lumbar facet cysts having underwent either hemilaminectomy, bilateral laminectomy, laminectomy with uninstrumented fusion, or laminectomy with instrumented fusion. Although no significant difference in cyst recurrence was found across all 4 treatment groups, subgroup analysis concluded laminectomy had a significantly increased cyst recurrence incidence compared with fusion groups. However, the recurrence of lumbar Received for publication April 1, 2019; accepted August 17, 2019. From the *Indiana Spine Group, Carmel, IN; and †Department of Orthopedic Surgery, NYU Langone Orthopedic Hospital, NYU Langone Health, New York, NY. B.S.B.: consultancy with Innovative Surgical Designs and Nexus Spine. J.D.S.: consultancy with Medtronic. R.C.S.: royalties with Medtronic. T.S.P.: consultancies with Globus, K2M, NuVasive, Medicrea, Innovasis. A.H.S. declares no conflict of interest. Reprints: Barrett S. Boody, MD, Indiana Spine Group, 13225 North Meridian Street, Carmel, IN 46032 (e-mail: [email protected]). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. CONTROVERSIES IN SPINE SURGERY