A Systematic Review and Meta-Analysis of Outcomes and Adverse Events for Juxtafacet Cysts Treatment =================================================================================================== * Enrico Giordan * Paolo Gallinaro * Altin Stafa * Giuseppe Canova * Roberto Zanata * Elisabetta Marton * Jacopo Del Verme ## Abstract **Background** Different procedures have been used for the treatment of lumbar juxtafacet cysts (JFCs). Recently, full-endoscopic cyst excision has been suggested as a reasonable alternative. We performed a meta-analysis to assess the overall rates of favorable outcomes and adverse events for each available treatment and determine the outcome and complication rates concerning spine stability. **Methods** Multiple databases were searched for English-language studies involving adult patients with lumbar JFCs who had been followed for more than 6 months. Outcomes included the proportion of patients with a satisfactory outcome. Adverse events included recurrence and revision rates as well as intraoperative complications. We further stratified the analysis based on the spine’s condition (degenerative listhesis vs without degenerative listhesis). **Results** A total of 43 studies, including 2226 patients, were identified. Over 80% of patients experienced satisfactory improvement after surgical excision but only 66.2% after percutaneous cyst rupture and aspiration. Overall, recurrence and revision rates were almost double in patients with preoperative degenerative listhesis at the cyst level, especially in the minimally invasive group (2.1% vs 31.3% and 6.8% vs 13.1%, respectively). The rate of full-endoscopic satisfactory outcomes was approximately 90%, with low rates of adverse events (<2%). **Conclusion** We analyzed the outcome and adverse event rates for each kind of available treatment for JFC. Full endoscopy has outcomes and rates of adverse events that overlap with open and minimally invasive approaches. **Level of Evidence** 2A. * juxtafacet cyst * lumbar * synovial cyst * endoscopic * spine * minimally invasive * percutaneous * cyst rupture ## INTRODUCTION Lumbar juxtafacet cysts (JFCs) are common in patients with degenerative spine disease and are responsible for radicular pain and neurological symptoms. The development of JFCs is linked to degenerative spondylosis, segmental instability, and trauma.1–3 The reported incidence of JFCs among patients undergoing lumbar surgery ranges from 0.1% to 0.8%, and degenerative listhesis is estimated to be present in 38% to 75% of these patients.4,5 JFC treatment’s mainstay is laminectomy/hemilaminectomy and cyst excision, sometimes coupled with total facetectomy and fusion.6 Conservative management or percutaneous cyst rupture and aspiration,7 typically used in the elderly or those unwilling or unsuited for surgical treatment,8 is mostly temporarily effective and has high recurrence rates.9–12 Recently, minimally invasive techniques have been used to treat such patients, expanding spinal surgeons' therapeutic choices.13 The full-endoscopic approach has also gained importance in the surgeon’s armamentarium and, more recently, has been used for degenerative disease treatment.14 Several studies have tried to review and compare the outcomes and adverse events of different surgical techniques for JFCs.15–17 However, because some of these studies did not report results per the surgical procedure, they lacked detailed information about their possible outcomes. This is especially true regarding patient selection based on suspected spine instability at the cyst level. Therefore, we restricted our literature analysis to studies with detailed information about surgical management and spine stability to compare actual surgical options. For the first time in literature, this resulted in an extensive stratified analysis of outcomes and adverse events for each type of procedure: open, minimally invasive, percutaneous, and full-endoscopic management of lumbar JFCs. ## Methods A comprehensive search of several databases (ie, PubMed, Epub Ahead of Print, Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus) was conducted with the help of an expert medical reference librarian. The search terms were “juxtafacet cyst,” “synovial,” “ganglion,” “lumbar,” “lumbar cysts,” “cyst,” and “spinal cyst,” which were used alone and in combination. Controlled vocabulary supplemented with the keywords was used to search for JFC formation in patients diagnosed with degenerative spinal diseases. Inclusion criteria were as follows: 1. description of JFCs in both longitudinal and retrospective series that discussed the following: * synovial cysts in continuity with the capsule of the facet joints * ganglion cyst 2. ≥5 patients 3. mean or median follow-up <6 months 4. published in English between January 2000 and April 2020 5. consecutive series of patients treated with the following: * percutaneous techniques (cyst rupture and aspiration) * open surgery (interlaminar approach or laminectomy/hemilaminectomy and cyst excision) * minimally invasive approaches (ipsilateral or contralateral microsurgical tubular approaches) * full-endoscopic surgery (interlaminar and/or transforaminal full-endoscopic access) 6. intraoperative or histological confirmation of JFCs 7. preoperative imaging adequate to assess spinal stability (either spine CT or MRI and dynamic x-ray) 8. patients who did not undergo instrumented fusion at the cyst level 9. patients with or without preoperative degenerative listhesis at cyst level Studies dealing with patients with higher than grade I preoperative degenerative listhesis based on the Meyerding classification,18 with vertebral body slippage confirmed through dynamic x-rays or in case of isthmic spondylolisthesis, were excluded. Among these patients, the spine was considered severely unstable and suitable only for fusion procedures, thus perceiving cyst formation as an epiphenomenon of severe spinal instability. Studies with patients who underwent prior instrumented fusion at the cyst level were excluded. ### Data Abstraction We categorized the studies into 4 groups based on surgical technique, including patients who underwent either surgical or microsurgical cyst excision in the open surgery group. We included studies on patients who underwent microsurgical cyst excision with tubular retraction system in the minimally invasive group. The full-endoscopic group included those studies with patients who underwent endoscopic interlaminar or transforaminal approaches. In the percutaneous group, we included studies only on patients who had undergone computed tomography (CT or fluoroscopically guided JFC rupture and aspiration). For each study, we extracted the following data: patient’s age (years), sex, JFC level, operative time (minutes), hospitalization time (days), follow-up (months), overall outcome, description of the procedure, intraoperative adverse events, whether the adverse events (both medical and surgical) manifested after more than 30 days, same-level JFC recurrence, the proportion of patients with preoperative spinal instability, method of assessing spinal instability (ie, spine CT, dynamic x-rays, or spine magnetic resonance imaging [MRI]), time from lumbar cyst treatment to the development of spinal instability at the affected level (months), and the proportion of patients requiring revision surgery for recurrence or developing instability at the treated level. We noted the surgical approach utilized for each surgical procedure (open vs minimally invasive vs full endoscopic vs percutaneous). We excluded patients with prior fusion surgery at the level of the JFC, but we collected the percentage of patients undergoing fusion surgery either at the surgery time or at developing instability. The outcomes were defined as "satisfactory" based on MacNab or modified MacNab criteria,19 and the values were collected at the last follow-up visit or at least 6 months after the intervention. Only excellent and good scores were considered satisfactory. In some studies, we extracted the degree of postoperative satisfaction (“excellent” and “good”) from scores or scales similar to or attributable to MacNab’s criteria. We included preoperative degenerative listhesis when the listhesis at the cyst level described in the pooled studies was within: (1) Meyerding grade 1 and (2) without vertebral body slippage on dynamic lumbar x-ray. Every other intervention at the previously treated level or additional arthrodesis to overcome a developing spinal instability was considered as “revision surgery.” In the percutaneous group, revisions were divided into 2 subgroups: those needing an additional percutaneous cyst puncture and those requiring surgical cyst excision for symptom control. The following intraoperative adverse events were considered: nerve root damage, dural tear, seroma, and epidural hematoma. When possible, we separately extracted the subpopulations of patients with confirmed preoperative degenerative listhesis from the investigated segment, calculating outcomes and adverse events for each population (no signs of preoperative degenerative listhesis or instability vs preoperative degenerative listhesis). We also abstracted the mean interval between the first surgery and the development of a more severe degree of spinal instability (ie, Meyerding grade