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Introduction: Spinal cysts have traditionally been treated with surgery since it was first described in 1950. However, there have been rare instances where these cysts have resolved on their own without the need for surgical intervention. Here, we discuss the 27th reported case of such spontaneous resolution in the medical literature and delve into the details of this unique case., Case Presentation: This report details a rare case of a 58-year-old Middle Eastern female who suffered from severe radicular and lumbar pain. Radiological study showed the presence of a cyst in the lumbar column. Noninvasive treatment was chosen after ensuring that there were no other symptoms requiring surgery. The patient showed gradual improvement over the course of 12 months, after which the pain completely disappeared., Discussion: The surgical approach is currently the main treatment for spinal cysts, but spontaneous resolution, despite its rarity, may be worth considering as a preferred therapeutic approach in the future. This avenue has not been thoroughly explored or studied. Due to the etiology of these cysts and their location within mobile joints, a longer period of conservative management including rest and physical therapy may play a pivotal role in promoting natural resolution., Conclusion: Conservative treatment of cysts should continue for at least 8 months, using painkillers and physical therapy without lumbar bracing. Surgery remains the most effective means of treatment to date. Further research is needed to validate and establish standardized treatment protocols., (© 2024. The Author(s).)

Tubular retractors in minimally invasive lumbar stenosis permit surgeons to achieve satisfactory neural decompression while minimizing the morbidity of the surgical access. 1-3 Transtubular lumbar decompression requires intraoperative image guidance and microscopic magnification to achieve precise and reproductible surgical results. Use of 2-dimensional image guidance in transtubular lumbar decompression has a major limitation due to the lack of multiplanar orientation. Consequently, there is a risk of incomplete decompression and excessive bone removal resulting in iatrogenic instability. Furthermore, available microscopes have limited optics (short focal lengths) and unsatisfactory surgeon ergonomics. To overcome these limitations, the authors present a step-by-step video of the navigated exoscopic transtubular approach (NETA) for spinal canal decompression (Video 1). The patient suffers from bilateral L5 radiculopathy due to L4-L5 bilateral synovial cysts responsible for severe L4-L5 canal stenosis. During the entire surgical procedure, NETA implements the use of navigation based on intraoperative 3-dimensional (3D) fluoroscopic images for retractor placement, bone mapping, and neural decompression. 4 NETA represents a modification of the "standard" MIS transtubular technique for bilateral lumbar decompression. NETA is based on the use of neuronavigation during each surgical step to guide the placement of tubular retractor. This tailors the bone resection to achieve adequate neural decompression while minimizing the risks of potential spine instability. After precise placement of the tubular retractor, bone removal and neural decompression are accomplished under robotic exoscope magnification with 4k 3D images. Using a 3D robotic exoscope (Modus V, Synaptive, Toronto, Canada) allows better tissue magnification and improves surgeon ergonomics during lumbar decompression through tubular retractors. 5 , 6 ., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Synovial or ganglion cysts are the most common soft tissue tumors of the wrist and hand and can arise from joints or tendons. Intratendinous synovial cysts, in contrast, are rare and their pathogenesis is still a matter of debate. The treatment of synovial cysts of articular origin using arthroscopy is commonly used with good results. For cysts of tendon origin, that is, extra-articular, when located at the ankle, shoulder, knee, and wrist, endoscopic treatment has also been described in a procedure called tenoscopy. We describe the technique and the good results using tenoscopy for a patient treated for an intratendinous synovial cyst located at the extensor communis tendon of the third digit. It is a reproducible, safe technique with low morbidity, and the patient has had no complications or recurrence., Competing Interests: Conflicts of Interest and Source of Funding: The authors report no conflicts of interest and no source of funding, (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Although lumbar synovial cysts (LSCs) are frequently described in the literature, they are a relatively uncommon cause of low back and radicular leg pain. Furthermore, their spontaneous resolution is an even rarer event. The standard treatment of the lumbar synovial cyst is surgical excision. Spontaneous resolution in the literature is a sporadic event. In our experience, we have had two cases where the lumbar synovial cyst disappeared spontaneously. To date, only nine cases of spontaneous resolution of synovial cysts have been documented in the literature. In this discussion, we highlight a pathology that typically suggests surgical intervention, yet conservative treatment can be a viable alternative. We present two cases of large synovial cysts that were initially scheduled for surgery but ultimately resolved spontaneously without any treatment. While the spontaneous resolution of lumbar synovial cysts is extremely rare, conservative strategies are an option that should not be overlooked. Our cases contribute to the growing body of evidence on the spontaneous regression of symptomatic LSC, potentially enhancing the understanding of the disease's natural progression in the future.

Background and Objectives: The term "Juxtafacet cyst" refers to both synovial cysts and ganglion pseudocysts associated with the lumbar facet joint. As conservative treatment for the juxtafacet cyst has a minimal effect, complete excision through surgery is considered the first choice of treatment. In this study, we retrospectively reviewed the clinical outcomes of percutaneous epidural neuroplasty for symptomatic lumbar juxtafacet cysts. Materials and Methods: We conducted a retrospective review of 34 patients with symptomatic juxtafacet cysts who visited a single institute from January 2010 to September 2023. Patients who received conservative treatment for at least 6 weeks but experienced no or insufficient effects were eligible for this study. After neuroplasty, a medical history check and neurological examination were performed during follow-up at 2 weeks, 1 month, 2 months, 3 months, 6 months, and once a year thereafter. Results: The pain improved for all patients to a VAS score of 3 or less immediately after neuroplasty; however, four of those patients (11%) had pain that worsened eventually to the same level as before the procedure and required surgery. The results showed that, regardless of cyst size, in cases with severe stenosis of the spinal canal, the outcome of neuroplasty was poor and often eventually required surgery. The cyst size was not associated with the procedure results. In addition, if the cyst was present at the L4-L5 level, or if diabetes mellitus was present, the likelihood of future surgery was significant ( p -value = 0.003). Conclusions : Percutaneous neuroplasty showed a better success rate than other non-surgical treatments. In addition, severe spinal stenosis (Schizas grade C or higher), L4-L5 level, or diabetes mellitus produced a high possibility of surgery due to recurrence.

Introduction: Inter-dural juxta-facet spinal cysts occur rarely. They form as part of the degenerative spinal disease process and can be misdiagnosed as synovial cysts or ganglion cysts. We report the case of a thoracic inter-dural juxta-facet spinal cyst causing acute compressive thoracic myelopathy., Methods: The data was collected retrospectively from patient records. The literature review was performed in PubMed., Results: We report a case of symptomatic inter-dural juxta-facet thoracic spinal cyst. The literature review showed a variety of different spinal cysts including arachnoid cyst, discal cyst, ganglion cyst, epidermoid cyst and synovial cysts. Micro-instability and repeated microtrauma associated with degenerative changes are most likely contributors to its formation. Asymptomatic cysts can show spontaneous resolution. When symptomatic, they can be managed with surgical excision with good patient outcome., Conclusion: Inter-dural spinal cysts can be diagnosed and surgically excised to produce excellent post-operative outcome. High pre-operative index of suspicion of this diagnosis together with good understanding of the intraoperative anatomy are essential to avoid inadvertent dural breach.

Ganglion cyst of the temporomandibular joint (TMJ) is an uncommon pathology with uncertain etiology. There is no consensus on their management. The current systematic review aimed to discuss the clinical and histopathological features of ganglion cysts of TMJ, to aid in appropriate treatment. A literature search was done and a total of 20 cases were retrieved from published databases such as PubMed, SCOPUS, and Google Scholar. The cyst presented with swelling in all the cases followed by pain (50 %) and trismus (35 %) as other common symptoms. Though CT and MRI proved helpful in determining the location of the cyst, a histopathological examination was essential in concluding its final diagnosis. It is a pseudocyst lined by dense fibro-connective tissue with myxoid tissue degeneration. Histologically, it is essential to distinguish them from the clinically and radiographically similar true cyst of TMJ, synovial cyst. The lining of ganglion cyst is devoid of epithelium and synovial cells. Surgical excision was found to be the treatment of choice with minimal recurrence (10 %) being reported., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The treatment of lumbar spinal synovial cysts (LSCs) which are relatively rare but can cause neurogenic dysfunction and intractable pain has been a controversial topic for many years. Surgical excision of LSCs is the standard treatment for patients in whom conservative treatment options fail. This meta-analysis was undertaken to compare clinical outcomes between minimally invasive approaches using tubular retractors (microscopic vs. endoscopic) and traditional percutaneous approaches for LSCs. Studies reporting surgical management of LSCs were searched in the Cochrane Library, PubMed and Web of Science database. This meta-analysis was reported following the PRISMA Statement, registered in Prospero (CRD42021288992). A total of 1833 patients were included from both the related relevant studies (41 studies, n = 1831) and the present series (n = 2). Meta-analysis of minimally invasive tubular approaches revealed no statistically significant difference in pain improvement, dural tear, residual cyst, recurrence and operation time between minimal groups with traditional groups (p > 0.05). Minimal groups had better Functional improvement of 100% (95% CI 1.00-1.00; p < 0.001, I 2  = 75.3%) and less reoperation rates of 0% (95% CI - 0.00-0.00; p = 0.007, I 2  = 47.1%). Postoperative length of hospital stay and intraoperative bleeding in minimal groups were also less than traditional groups (p < 0.05). Subgroup analysis revealed endoscopic groups had less operation time (p = 0.004), and there was no significant difference in the rest. For patients with LSCs but without obvious clinical and imaging evidence of vertebral instability, even when preoperative stable grade 1 spondylolisthesis is present, minimally invasive tubular approaches without fusion may provide the best outcome in surgical management., (© 2023. The Author(s).)

Synovial cysts of the spine are degenerative cystic lesions that can lead to severe symptoms secondary to compression of the spinal cord, individual nerve roots, and/or the cauda equina. Some believe the etiology of this entity is related to increased motion across the facet joint and instability. We report a case of a lumbar synovial cyst located at the same level as a previously inserted spinous process fusion device. This case illustrates that, unlike a transpedicular instrumented fusion where the risk of synovial cyst formation is zero, a spinal process fusion can still lead to synovial cyst formation likely due to persistent micromotion across that segment., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Facet joint (FJ) disease is a common cause of axial low back pain with many minimally invasive image-guided treatment options. This article discusses fluoroscopic and CT-guided intraarticular FJ injections, medial branch (MB) radiofrequency ablation (RFA), and lumbar facet synovial cyst (LFSC) aspiration, rupture, or fenestration. Additionally, the article will highlight medial branch blocks (MBBs) utilized to diagnose facet-mediated pain and to predict outcomes to RFA., (© 2022. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Hemorrhage into a juxtafacet cyst is rare and cyst rupture with hemorrhagic extension into the epidural space is even less commonly seen. We describe the case of a patient with a hemorrhagic synovial cyst with rupture associated to abundant bleeding in the epidural space. A 61-year-old man had a 5-month history of worsening low back pain radiating into the right leg with associated weakness and numbness. A magnetic resonance imaging scan showed the presence of a mild anterior spondylolisthesis of L5 on S1 with increased synovial fluid into both facet joints. A suspected synovial cyst of the right facet joint at level L5-S1, with signal characteristics consistent with hemorrhage was seen. Caudally, epidural blood was evident from S1 to S2 that involved spinal canal and right S1 and S2 foramens. These findings were confirmed at surgery.

Objective: Lumbar facet cysts (LFCs) can cause neurological dysfunction and intractable pain. Surgery is the current standard of care for patients in whom conservative therapy fails, those with neurological deficits, and those with evidence of spinal instability. No study to date has comprehensively examined surgical outcomes comparing the multiple surgical treatment options for LFCs. Therefore, the authors aimed to perform a combined analysis of cases both in the literature and of patients at a single institution to compare the outcomes of various surgical treatment options for LFC., Methods: The authors performed a literature review in accordance with PRISMA guidelines and meta-analysis of the PubMed, Embase, and Cochrane Library databases and reviewed all studies from database inception published until February 3, 2023. Studies that did not contain 3 or more cases, clearly specify follow-up durations longer than 6 months, or present new cases were excluded. Bias was evaluated using Cochrane Collaboration's Risk of Bias in Nonrandomised Studies-of Interventions (ROBINS-I). The authors also reviewed their own local institutional case series from 2015 to 2020. Primary outcomes were same-level cyst recurrence, same-level revision surgery, and perioperative complications. ANOVA, common and random-effects modeling, and Wald testing were used to compare treatment groups., Results: A total of 1251 patients were identified from both the published literature (29 articles, n = 1143) and the authors' institution (n = 108). Patients were sorted into 5 treatment groups: open cyst resection (OCR; n = 720), tubular cyst resection (TCR; n = 166), cyst resection with arthrodesis (CRA; n = 165), endoscopic cyst resection (ECR; n = 113), and percutaneous cyst rupture (PCR; n = 87), with OCR being the analysis reference group. The PCR group had significantly lower complication rates (p = 0.004), higher recurrence rates (p < 0.001), and higher revision surgery rates (p = 0.001) compared with the OCR group. Patients receiving TCR (3.01%, p = 0.021) and CRA (0.0%, p < 0.001) had significantly lower recurrence rates compared with those undergoing OCR (6.36%). The CRA group (6.67%) also had significantly lower rates of revision surgery compared with the OCR group (11.3%, p = 0.037)., Conclusions: While PCR is less invasive, it may have high rates of same-level recurrence and revision surgery. Recurrence and revision rates for modalities such as ECR were not significantly different from those of OCR. While concomitant arthrodesis is more invasive, it might lead to lower recurrence rates and lower rates of subsequent revision surgery. Given the limitations of our case series and literature review, prospective, randomized studies are needed.

BACKGROUND This study was performed to evaluate the clinical effectiveness of needle aspiration vs surgical excision for symptomatic synovial cysts of the hip. MATERIAL AND METHODS This retrospective study analyzed the clinical data of patients diagnosed with synovial cysts of the hip and treated in a single-center hospital from January 2012 to April 2022. Patients receiving needle aspiration were assigned to group A and those treated with surgery were assigned to group B. Demographic characteristics, etiology, symptoms, cyst location, postoperative complications and recurrence, Harris Hip Score (HHS) and Visual Analog Scale of Pain (VAS) scores before treatment and at 3, 6, and 12 months after treatment were recorded to assess hip function in both groups. RESULTS This study recruited 44 patients, with 18 patients in group A and 26 in group B, and the 2 arms were well-balanced in terms of baseline patient profiles. Needle aspiration resulted in significantly better pain mitigation for patients at 24 h, 48 h, and 72 h after treatment vs surgical interventions (P<0.05). Needle joint aspiration resulted in significantly better function restoration of the hip joint than surgery at 3 months after treatment, as evidenced by the lower HHS score of 85.31±13.16 in group A vs 78.51±11.66 in group B (P=0.002). Surgery was associated with a significantly lower incidence of disease relapse (0.00%) vs needle aspiration (27.7%) (P=0.004). CONCLUSIONS Needle aspiration in the treatment of symptomatic synovial cysts of the hip causes less damage to the soft tissue and leads to faster recovery in the short term than surgical resection. Surgical resection has a lower recurrence rate and better long-term efficacy.

Background: Spinal synovial cysts are lesions that most commonly occur in the lumbar region. The need for an instrumented spinal fusion in addition to lumbar decompression with removal of the synovial cyst is unknown., Objective: To test the hypothesis that select patients who underwent decompression with instrumented fusion for lumbar synovial cysts would be less likely to have subsequent surgery (SS) in a 2-year period than patients treated with laminectomy alone., Methods: This retrospective cohort study was performed using IBM MarketScan Commercial Claims and Encounters Database. Patients who had a lumbar synovial cyst diagnosis and laminectomy surgery with or without fusion surgery were included in this study. Patients were tracked for SS 2 years after surgery. Laminectomy patients were propensity score-matched to laminectomy with fusion (LF) patients using a 2:1 ratio. The log-rank test and Cox regression were used to compare the cumulative incidence of SS between groups., Results: There were 7664 and 1631 patients treated with laminectomy and LF before matching. After matching, there were 2212 laminectomy and 1631 LF patients and patient characteristics were balanced. The 2-year incidence of recurrent SS was 3.1% ([CI]: 2.2%, 4.0%) and 1.7% (95% CI: 0.9%, 2.5%) laminectomy and LF, respectively. Compared with laminectomy, LF had a statistically significant lower risk of recurrent SS (hazard ratio: 0.56 [95% CI: 0.32-0.97]; P -value: .04)., Conclusion: All patients who had concomitant lumbar fusion showed decreased chance of having a cyst- or noncyst-related recurrence SS when compared with all patients undergoing laminectomy alone, regardless of diagnosis at the time of SS., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Purpose: Ganglion cysts are benign soft tissue lesions found in joints, most commonly wrists. The incidence for juxtafacet cysts, the condition under which spinal ganglion cysts are categorized, is between 0.06% and 5.8%. Spinal ganglion cysts often arise in the most mobile segment of the lumbar spine, L4-L5. Patients commonly present with pain, radiculopathy, and weakness. Conservative management is used, but surgical resection is the most common treatment modality. We aim to review the literature and present a rare case of an L2-L3 situated spinal ganglion cyst, treated with maximal safe resection., Methods: A systematic review of literature was conducted in accordance with PRISMA guidelines. PubMed, Web of Science, and Cochrane databases were queried using Boolean operators and search terms, "spinal ganglion cyst, lumbar ganglion cyst, and lumbar juxtafacet cyst". Presentation, surgical management, and postoperative course of a 29-year-old male with an L2-L3 spinal ganglion cyst are also described., Results: The search yielded 824 articles; 23 met inclusion criteria. These papers consisted of 27 spinal ganglion cyst cases with disaggregated patient data. 63.0% of patients were male, and 53.4 years (range: 23-86) was the average age at presentation. Mean symptom duration was 1.9 years (range: 3 days-12 years). 70.4% of patients reported complete symptom resolution. 14.8% of cases noted neural foramen involvement., Conclusions: Spinal ganglion cysts are benign lesions typically presenting with radiculopathy. Maximal safe resection is an effective treatment modality with low complication rates. Future studies are needed to understand if neural foramen involvement leads to increased symptom severity., Competing Interests: Declaration of Competing Interest All authors declare that they have no personal, financial, or institutional conflict of interest., (Copyright © 2022. Published by Elsevier B.V.)

Objective: To evaluate effectiveness and safety of computed tomography (CT)-guided cyst rupture with intraarticular contrast-enhanced injection of steroid and local anesthetic as first choice therapy in patients with facet joint cyst-induced radicular pain., Design: Retrospective data set analysis., Setting: University hospital., Subjects: One hundred and twenty-one patients suffering from radicular pain attributable to facet joint cysts were included., Methods: The rate of patients without following surgery was assessed and defined as surrogate to measure effectiveness. Patients' characteristics, procedure-associated complications, technical aspects, and imaging findings on magnetic resonance imaging (MRI) were analyzed. A subgroup of 65 patients (54%) underwent telephone interview to assess pain relief and clinical outcome measured by Numeric Rating Scale and Oswestry Disability Index. Analyses between the groups with and without surgery were performed by Fisher exact test and two-sample unpaired t-test, respectively., Results: The effectiveness of CT-guided cyst rupture was found to be 66.1%. Procedure-induced pain yielded in premature abort in two cases (1.7%). The detection of epidural contrast agent was statistically significantly associated with no need for surgery (P = .010). The cyst level was associated with the status of following surgery (P = .026), that is, cysts at lower lumbar spine were easier to rupture than cysts at other locations (cervical, thoracic, or upper lumbar spine). No further significant association was found., Conclusions: CT-guided cyst rupture as the first-choice therapy in patients with cyst-induced radicular pain was safe and effective. Successful cyst rupture was associated with no need for surgery. Cysts at lower lumbar spine revealed the highest success rate., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Lumbar synovial cysts (LSCs) can cause painful radiculopathy and sensory and/or motor deficits. Historically, first-line surgical treatment has been decompression with fusion. Recently, minimally invasive laminectomy without fusion has shown equal or superior results to traditional decompression and fusion methods., Objective: This study investigates the long-term efficacy of minimally invasive laminectomy without fusion in the treatment of LSC as it relates to the rate of subsequent fusion surgery., Methods: A retrospective review was performed over a 10-year period of patients undergoing minimally invasive laminectomy for symptomatic LSCs. The primary end point was the rate of revision surgery requiring fusion., Results: Eighty-five patients with symptomatic LSCs underwent minimally invasive laminectomy alone January 2010-August 2020 at our institution. The most common location was L4-5 (72%). Preoperative imaging identified spondylolisthesis (grade 1) in 43 patients (57%), none of which was unstable on available dynamic radiographs. Average procedure duration was 93 minutes, with 78% of patients discharged home on the same day of surgery. Over 46 months of mean follow-up, 17 patients (20%) required 19 revision operations. Of those operations, 16 were spinal fusions (17.6%). Median time to fusion surgery was 36 months. There were no identifiable risk factors on multivariate regression analysis that predicted the need for fusion., Conclusions: Minimally invasive laminectomy is an effective first-line treatment for symptomatic LSCs and avoids the need for fusion in most treated patients. Of our patients, 18% required a fusion over 46 months, suggesting that further studies are required to guide patient selection., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Spinal synovial cysts are acquired, fluid-filled lesions of the facet joint that most commonly occur in the lumbar spine. They are thought to arise from degenerative changes and to result from segmental instability. Although the treatment of these lesions has been studied, the long-term implications and effects of the different strategies for surgical intervention (i.e., decompression and fusion vs. decompression alone) have not yet been elucidated or established., Methods: Using an all-payer database with 53 million patient records (MARINER-53), patients with a diagnosis of lumbar synovial cysts were identified. Patients who had undergone lumbar fusion versus laminectomy were matched 1:1 using binomial and gaussian logistic regression models to evaluate the need for future lumbar surgery within 5 years after their index procedure., Results: No statistically significant differences were noted between the 5-year rates of subsequent intervention, additional laminectomy, or fusion among patients who had undergone index decompression and fusion (n = 51; 10.5%) versus decompression alone (n = 43; 8.8%; P = 0.39). Furthermore, no significant differences were found in the odds of intervention type after index decompression and fusion versus decompression alone (subsequent laminectomy: odds ratio, 0.59; 95% confidence interval, 0.32-1.09; subsequent fusion: odds ratio, 1.14; 95% confidence interval, 0.64-2.02)., Conclusions: Patient-specific factors and surgeon-patient-shared decision-making should be used when planning interventions for these lesions. However, synovial cysts might not require a fusion procedure for presumed instability. Further investigation is required, using randomized and prospective studies, to further evaluate the effective treatment of this entity., (Published by Elsevier Inc.)

Temporomandibular joint (TMJ) synovial cysts are rare, unlike peripheric locations like the wrist or the knee. They share similar presentations with ganglion cyst, benign and sometimes malignant lesions. Only histopathological analysis confirms diagnosis in some cases, finding a true cyst lined by synoviocytes containing synovial fluid. They seem to be related to an increased articular pressure following trauma. In this study we present two cases of TMJ synovial cyst and a systematic review of the literature. A total of 32 cases were retrieved from published literature in PubMed, Cochrane Library and ClinicalTrials.gov databases using the search terms 'TMJ synovial cyst', 'temporomandibular synovial cyst', 'jaw joint synovial cyst'. Swelling (91.3%) and pain (78.3%) were the most common symptoms. MRI was the most commonly used imaging modality that was found to be beneficial for diagnosis. In almost all cases the cyst was removed under general anesthesia, allowing histopathological examination. Only two patients still had pain after removal of the cyst. No recurrence was observed ., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Objective: Lumbar synovial cysts (LSCs) represent a relatively rare clinical pathology that may result in radiculopathy or neurogenic claudication. Because of the potential for recurrence of these cysts, some authors advocate for segmental fusion, as opposed to decompression alone, as a way to eliminate the risk for recurrence. The objective of this study was to create a predictive score for synovial cyst recurrence following decompression without fusion., Methods: A retrospective chart review was completed of all patients evaluated at a single center over 20 years who were found to have symptomatic LSCs requiring intervention. Only patients undergoing decompression without fusion were included in the analysis. Following this review, baseline characteristics were obtained as well as radiological information. A machine learning method (risk-calibrated supersparse linear integer model) was then used to create a risk stratification score to identify patients at high risk for symptomatic cyst recurrence requiring repeat surgical intervention. Following the creation of this model, a fivefold cross-validation was completed., Results: In total, 89 patients were identified who had complete radiological information. Of these 89 patients, 11 developed cyst recurrence requiring reoperation. The Lumbar Synovial Cyst Score was then created with an area under the curve of 0.83 and calibration error of 11.0%. Factors predictive of recurrence were found to include facet inclination angle > 45°, canal stenosis > 50%, T2 joint space hyperintensity, and presence of grade I spondylolisthesis. The probability of cyst recurrence ranged from < 5% for a score of 2 or less to > 88% for a score of 7., Conclusions: The Lumbar Synovial Cyst Score model is a quick and accurate tool to assist in clinical decision-making in the treatment of LSCs.

Background: There is controversy regarding the treatment of symptomatic synovial cysts, specifically, the need for a concomitant fusion when surgical resection of the synovial cysts is required. We present a retrospective review of a series of patients treated for symptomatic synovial cysts of the lumbar region during the last 20 years by a single surgeon, analyzing the current available literature., Methods: Retrospective review. The same surgical technique was applied to all patients. Demographic, clinical, surgical data and synovial cyst recurrence rate were recorded. Postoperative results reported by patients were documented according to the McNab score., Results: Sixty nine subjects, with mean follow-up of 7.4 years. 62% (43) were female, with a mean 57.8 years at the time of surgery. In 91.3% (63), the primary management was conservative for a minimum period of 3 months. All subjects underwent surgery due to the failure of conservative treatment. The segment most operated on was L4-L5 (63.77%). 91.3% (63) of the sample reported excellent and good and 6 subjects (8.6%) fair or poor results. There was no evidence of synovial cysts recurrence at the operated level., Conclusion: In symptomatic synovial cysts, it seems that conservative treatment is only effective in a limited number of patients and in the short term. Thus, the recommendation of a surgical indication should proceed as soon as the conservative management fails to result in significant symptom relief. Based on our results, we recommend, together with the resection of the cyst, the instrumentation of the segment to avoid its recurrence and the management of axial pain., (© 2022. The Author(s).)

Symptomatic bilateral juxtafacet ganglion cysts are relatively uncommon in the degenerated spine. The literature describes 16 cases of bilateral ganglion or synovial cysts, none reported sciatica and neurogenic claudication simultaneously. We present a case of a 60-year-old woman who presented with symptoms of bilateral sciatica and neurogenic claudication. Magnetic resonance imaging of the lumbar spine revealed bilateral lesions related to the facet joints at the L4/5 level, causing bilateral lateral recess stenosis and narrowing of the central canal due to encroachment of these bilateral lesions at the same level. She underwent an elective central canal decompression of the L4/5 level and excision of the facet cysts bilaterally with lateral recess decompression, which resulted in good relief of both the radicular and claudication symptoms.

Background: The presence of symptomatic lumbar facet cysts has been associated with segmental instability. Given this association, decompression versus decompression with fusion is a frequently debated topic. Multiple grading scales have been devised to identify patients at high risk for development of cyst recurrence; however, there exists no external evaluation of these scales., Methods: A retrospective review of 54 patients undergoing initial treatment for lumbar synovial cysts at a single institution over the past 12 years was conducted. Surgical treatment consisted of decompression with cystectomy without fusion. Patients were assessed and classified according to the NeuroSpine Surgery Research Group (NSURG) and Rosenstock Classification systems. Five neurosurgeons reviewed the preoperative magnetic resonance images, and results were classified. Interrater reliability was assessed using both Gwet's AC1 coefficient and Krippendorff's alpha. A 1-way analysis of variance was used to evaluate predictive ability of both classification systems., Results: In total, of the 54 patients who underwent decompression, 7 had cyst recurrence. Overall cyst recurrence was most common in NSURG grade 2 cysts (3/12, 25%) followed by grade 1 cysts (4/27, 14.8%). Of the NSURG grade 3 and 4 patients, none had cyst recurrence. In the Rosenstock grades the most common recurrence was in grade 3 cysts (1/4, 25%) followed by grade 1 cysts (5/26, 19.2%). Interrater reliability demonstrated good reproducibility on Gwet's AC1 and Krippendorff's alpha on both grading scales. Neither score was predictive of cyst recurrence (P > 0.05)., Conclusions: The Rosenstock and NeuroSpine scores demonstrate good overall interrater reliability but are inconsistent in their ability to predict recurrence of lumbar facet cysts., (Crown Copyright © 2021. Published by Elsevier Inc. All rights reserved.)

Objective: Numerous studies have reported on synovial facet joint cysts of the spine as a primary lesion. The exact pathogenesis of those cysts is still controversial, but degeneration and destabilization seem to be underlying mechanisms. However, only a few reports have thus far investigated synovial cysts of the spine as postoperative complications of decompression surgery. In this retrospective clinical study, the authors focused on synovial cysts of the lumbar facet joints as complications after lumbar decompression surgery, with the aim of elucidating their pathophysiology., Methods: A total of 326 patients with 384 segments treated with posterior decompression surgery without fusion were included in the study. Of these segments, 107 were surgically decompressed unilaterally and 277 were decompressed bilaterally. After surgery, 18 of the 384 segments developed a complication of symptomatic facet synovial cyst. The anatomical and morphological evaluations of these segments were performed using functional plain radiographs, CT scans, and MR images., Results: All of the 18 segments with postoperative lumbar facet synovial cyst were treated with bilateral lumbar posterior decompression. There was no significant radiological lumbar spinal instability in any segments, although 17 of 18 segments demonstrated facet articular spondylotic changes. Moreover, 12 of 18 patients demonstrated lumbar retrolisthesis in the neutral position., Conclusions: Based on the authors' results, they propose that patients with lumbar degenerative disease who have a potential biomechanical lumbar instability such as disruption of the facet articular surface and hydrarthrosis or lumbar facet tropism might have a high risk for formation of lumbar facet synovial cyst after bilateral posterior decompression surgery.

Objective: Lumbar synovial cysts (LSC) are one of the manifestations of spinal degenerative cascade. Spinal stenosis or presence of instability in these patients can lead to various symptoms and surgery is indicated following failure of non-operative management for symptomatic synovial cysts. Surgery when performed consists of either decompression with resection of cyst with our without fusion. The efficacy and complications of minimally invasive techniques using tubular retractors (microscopic or endoscopic) in comparison to traditional open techniques remain to be studied., Methods: A comprehensive search of different databases was performed to retrieve studies describing the use of minimal invasive techniques using tubular retractors (both microscopic and endoscopic) in patients with LSC. Meta-analysis with subgroup analysis and metaregression was done., Results: Twenty articles were selected for the systematic review and meta-analysis with total of 388 patients. Eighty-six percent of patients (95% Confidence Interval (CI): 80-90%) had favorable outcome as per Macnab's criteria (excellent and good outcome) with the pooled standard mean difference between preoperative and postoperative Oswestry Disability Index (ODI) being -4.44 (95% CI -8.78 to -0.10, p-value=0.0474, I 2 82%). The pooled percentage change in visual analogue scale (VAS) after surgery was 76.5% (95% CI 66.9-84%, I 2 82%). The pooled proportion of incidental durotomies, cyst recurrence and patients requiring operation being 8% (95% CI 5-11%, I 2 0%), 4% (95% CI 2-7%, I 2 0%,) and 5% (95% CI 3-9%) respectively. Studies were homogeneous with an I 2 value of 0%. Subgroup analysis revealed no significant difference in the outcome rates or complication rates between the microscopic and endoscopic subgroups., Conclusion: Minimally invasive techniques for the resection of LSC is a safe and effective alternative to traditional surgical approaches with no difference between the microscopic and endoscopic approaches., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Cystic adventitial disease is a rare, nonatherosclerotic disease that affects various arteries and veins, involving the formation of a mucinous cyst within the adventitia. The etiology of the cystic adventitial disease is currently unclear, with several hypotheses having been suggested. The purpose of this retrospective observational study was to evaluate the etiology of popliteal cystic adventitial disease based on imaging and surgical findings and to evaluate the efficacy of surgical treatment., Methods: From April 2013 to January 2020, nine patients were diagnosed with the popliteal cystic adventitial disease and underwent surgical treatment. We performed complete resection of the cyst and the affected segment of the popliteal artery, followed by interposition with autologous reversed small saphenous vein or great saphenous vein., Results: The resected adventitial cyst tissue was multilobular, filled with high-viscosity mucus. Pathologic examination of the surgical specimen revealed intramural cysts filled with gelatinous material located between the media and the adventitia, consistent with the clinical diagnosis of cystic adventitial disease. The median follow-up period was 27.5 months (range: 2-91 months). All patients underwent cyst excision with graft interposition, and the overall graft patency was 80.9 months (95% CI: 62.2-99.6 months)., Conclusions: Computed tomography, magnetic resonance imaging, and surgical findings confirmed communication between the synovial cyst and arterial adventitia. It is recommended that priority be given to surgical resection and graft interposition because this can eliminate the disease's cause and reduce its recurrence., (Copyright © 2020. Published by Elsevier Inc.)

Background: The management of lumbar synovial cysts (LSC) has been a controversial topic for many years. Whereas many authors label LSC as markers of instability and thus necessitating fusion, others suggest that decompression alone without fusion is a viable initial treatment option. Our objective was to clarify outcomes in patients undergoing decompression alone and decompression with fusion for symptomatic LSC and identify factors for cyst recurrence., Methods: A retrospective case series was performed of all patients undergoing initial treatment for LSC at a single institution ranging from January 1999 to February 2020. Surgical treatment included either decompression with cystectomy or decompression with cystectomy and a fusion procedure. Preoperative symptoms were collected and included radicular pain, motor deficits, sensory deficits, or bowel/bladder changes. Radiographic data were calculated individually and confirmed with radiology reports. Categorical variables were assessed using χ 2 analysis and continuous variables were assessed with the 2-sample t test., Results: In total, 161 patients were identified as presenting with symptomatic LSC. Of these, 104 patients underwent decompression alone versus 57 who underwent decompression and fusion. In the decompression group 11 patients required reoperation at the level of the cyst compared with none in those undergoing fusion as their initial procedure (10.5% vs. 0%, P = 0.012). On subgroup analysis of those undergoing decompression as their initial procedure, patients with cyst recurrence demonstrated a statistically significant greater coronal facet inclination angle compared with those without cyst recurrence (52.4° vs. 40.6°, P = 0.02)., Conclusions: Decompression alone is a reasonable choice for the initial management of LSC, although it does carry a significant risk of same-level reoperation due to cyst recurrence and spondylolisthesis. Preoperative coronal facet inclination angle may be a useful measurement in predicting cyst recurrence following decompression., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Ganglion cysts are benign soft tissue lesions, usually arising from periarticular connective tissue. These are very rarely reported in the spine, but when seen can cause radiculopathy or myelopathy., Case Presentation: A 68-year-old female patient presented with worsening radiculopathy and right foot drop and imaging noted a right L5-S1 foraminal mass. The lesion was gross totally resected. Histological analysis revealed myxoid degeneration and inflammation, without a synovial lining, consistent with ganglion cyst., Discussion: While uncommon, intra-foraminal ganglion cysts can be distinguished from synovial cysts through imaging and histology and are typically amenable to surgical resection. Greater knowledge and insight about differentiating ganglion versus synovial cyst may prevent resection of facet joints and prevent a fusion procedure.

The authors report a patient with neuropathy of inferior gluteal and pudendal nerves following periarticular synovial cyst of the hip joint. Effectiveness of treatment was analyzed. ENMG and MRI of pelvic soft tissues and hip joint were applied to confirm neuropathy of inferior gluteal and genital nerves. Periarticular synovial cyst of the hip joint followed by compression and ischemia of inferior gluteal and pudendal nerves was detected. In pre- and postoperative period, intensity of pain syndrome was assessed using visual-analogue scale. Neuropathic pain and quality of life were evaluated using the Leeds scale (LANSS) and NeuroQoL questionnaire, respectively. The patient underwent microsurgical neurolysis and decompression of inferior gluteal and pudendal nerves and resection of periarticular synovial cyst of the hip joint. Complete regression of pain syndrome and improvement in quality of life were observed after surgery. Compression of neurovascular structures with periarticular hip cysts followed by clinical and neurological disorders is an indication for microsurgical neurolysis and resection of cyst.

Aim: To examine the prevalence of symptomatic lumbar synovial facet cysts in lumbar spinal magnetic resonance imaging (MRI) of patients who admitted to neurosurgery clinic, retrospectively. Also, we aimed to report the clinic and radiologic outcome of patients with symptomatic spinal synovial cyst, who undergo conservative treatment., Material and Methods: One thousand two hundred forty-three patients who admitted to Ordu University Neurosurgery outpatient clinic between 2015-2019 and underwent lumbosacral MRI and lumbosacral computed tomography examinations were reviewed retrospectively. The disappearance of cysts during radiologic follow up was accepted as spontaneous complete resolution, besides reduction in cyst dimensions and/or contrast enhancement were considered as radiologic regression. Decrease in radiculopathy, back pain and neurologic deficit complaints were also considered as clinical improvement., Results: Thirteen patients (8 men, 5 women) with lumbar synovial cysts who admitted to the neurosurgery outpatient clinic with low back and radicular pain complaints were included in the study. Nine patients (69.2%) had clinical and radiological improvement, 1 female patient (7.7%) was operated due to the leg pain, progressive motor deficit and lumbar disc hernia. Radiological spontaneous complete resolution was detected in 3 patients (23.1%). Spontaneous complete resolution period was determined between 3 months to 24 months., Conclusion: The symptomatic lumbosacral synovial cyst treatment algorithm has not been fully demonstrated. However, as in our series, spontaneous complete resolution of cysts and effectiveness of conservative treatment in symptomatic patients should not to be underestimated and immediate invasive procedures should be postponed.

Of Background Data: Despite a good understanding of the natural history of spinal synovial cysts (SCs), a widespread agreement regarding their optimal management is still lacking. This is particularly true for SCs occurring at the C1-C2 level, which are rare, but oftentimes lead to a rapidly evolving cervical myelopathy., Methods: We report a series of 4 patients (M:F ratio=1:1; mean age 63.5 years) presenting with progressive cervical myelopathy secondary to ventrally located C1-C2 SCs. All patients underwent a postero-lateral facet-sparing intradural approach with total excision of the SCs. Functional status was assessed pre- and postoperatively with Nurick scale and the modified Japanese Orthopaedic association grading. Furthermore we conducted a systematic review, following PRISMA guidelines of pertinent literature to contextualize the options for surgical management of such lesions., Results: Complete excision of the SCs was confirmed radiologically and on histological analysis. All measures of functional status improved post-operatively, and no cyst recurrence or need for instrumented fusion were noted during follow up (range from 22 to 88 months)., Conclusion: Our experience suggests that the facet-sparing intradural approach provides excellent clinical outcomes without causing any C1-C2 instability. This is in keeping with the take home message emerging from our literature review, which confirms that treatment should aim at radical resection of SCs while minimizing the risk of postoperative instability., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Background: Lumbar juxtafacet cysts are benign lesions that grow at the level of facet joints or within neighboring structures. Recently, there is an ongoing trend toward less invasive procedures for treating degenerative spine diseases. Here we report a multicenter study of full-endoscopic surgery for juxtafacet cyst removal., Methods: We prospectively collected patients with a diagnosis of lumbar juxtafacet cyst surgically treated in 3 institutions between January 2017 and August 2019. Patients of any sex and age were eligible if they had a single level unilateral lumbar juxtafacet cyst, invalidating radicular pain lasting >6 weeks, adequate imaging, and failed percutaneous or conservative treatment. Age at diagnosis; sex; preoperative, postoperative, and 6-month leg pain; surgical and medical complications; spine instability (preoperatively and at 6 and 12 months); and follow-up time were collected., Results: Thirty-five patients were enrolled. Median operative time was 78 minutes, and mean leg pain went from a preoperative value of 6.8 (standard deviation [SD] = 1.2) to a postoperative value of 3.4 (SD = 1.1, P < 0.001) to 2.1 (SD = 1.7, P < 0.001) at 6 months. At a median follow-up of 15 months, approximately 89% of patients were pain-free or improved. We had 2 recurrences of radicular pain, treated conservatively. Only 2 surgical complications (6%) occurred: 2 small dural tears, both resolved without further intervention., Conclusions: Full-endoscopic surgery is feasible and safe for juxtafacet cyst removal. Our results are consistent with findings from recent full-endoscopic and series, with outcomes overlapping those reported for open or tubular techniques., (Copyright © 2020 Elsevier Inc. All rights reserved.)

We report the case of a patient with a right-sided L4 synovial cyst, which had been causing significant pain, who had a successful transfacet epidural steroid injection to rupture the cyst. Using fluoroscopy, the needle was advanced through the right L4 facet joint and the cyst was ruptured using saline. The needle was then advanced into the epidural space and a transfacet epidural steroid injection was done. The patient's symptoms resolved. Repeat magnetic resonance imaging (MRI) done 2 years later showed no recurrence of the cyst. We discuss the role of transfacet epidural steroid injection in synovial cysts treatment.

Study Design: Case report., Objective: To describe a modified posterior approach for decompression and excision of a multiloculated atlanto-axial cyst., Summary of Background Data: Atlanto-axial cyst with myelopathy is rare. A direct decompression through anterior approach or an indirect decompression through posterior approach has been proposed. We report a rare multiloculated large C1-C2 cyst extending down to C3 body with myelopathy that created a dilemma in choice of approach. A modified posterior approach was adopted for decompression., Methods: A 72-year-old lady, known case of Rheumatoid arthritis, presented with cervical myelopathy which was rapidly progressive since 2 months being her to wheel chair bound. She had clumsiness of gait and bilateral grip weakness. Both upper and lower extremities had nonfunctional power (medical research council scale grade 2). Deep tendon reflexes were exaggerated. Sensation was reduced in trunk and both extremities. Magnetic resonance imaging and computed tomography scan showed a large multiloculated cyst compressing spinal cord. Here author used modified posterior approach from the right side to access the cyst. The C2 ganglion excision, vertebral artery isolation, and resection of the pars allowed an approach similar to transforaminal decompression in the lumbar spine. A large antero-lateral epidural part of the cyst was excised. The retro-dental cyst was decompressed by puncturing cyst. Biopsy confirmed a synovial cyst., Result: The patient showed rapid neurological recovery after surgery. Postoperative magnetic resonance imaging at 3 months showed complete resolution of cyst. At 2-year follow-up, there was a complete neurological recovery with residual spasticity., Conclusion: A customized posterior approach allowed near total excision of a rare multiloculated large C1-2 cyst extending to the C3 body. This allowed visualisation anterior to the spinal cord without undue retraction that saved an additional anterior decompression., Level of Evidence: 5.

Synovial cysts of the lumbar spine result from degeneration of the facet capsule, and their prevalence may be as high as 10% in symptomatic patients. Although conservative management is possible, the majority of patients will require resection. Traditional procedures for resection use an ipsilateral approach requiring partial or complete resection of the ipsilateral facet complex, possibly leading to further destabilization. A contralateral technique using minimally invasive tubular retractors for synovial cyst resection avoids facet disruption, minimizes soft-tissue trauma, and limits disruption of the ligamentous and bony structures. Additionally, by approaching contralateral, the cyst/dura interface is better visualized especially at the depths of the lateral recess. Seeing the full extent of this interface from an ipsilateral approach is very difficult without decompressing the cyst, which, in turn, makes dissecting and separating the remaining cyst wall more difficult and increases the risk of durotomies.1,2  We report the case of a 53-yr-old female who presented with persistent left leg pain in an L5 distribution that was associated with some mild lower back pain. She was refractory to conservative management that included physical therapy along with a series of epidural steroid injections. She was noted to have some weakness with dorsiflexion on the left side and as absent a straight leg raise. Given the predominance of her leg over her back symptoms along with the patient's age, a minimally invasive contralateral approach for resection of the synovial cyst was offered as opposed to more traditional decompression and fusion. Institutional Review Board approval and patient consent for solitary case reports are not needed at our institution., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Case: The exact underlying etiology behind synovial facet cysts remains unclear, and optimal surgical management continues to be a challenge. The authors present a series of 3 patients who underwent primary lumbar decompression and developed postoperative facet cysts within 6 months of index surgery requiring operative intervention. No patients had radiographic evidence of instability. Average follow-up after revision surgery was 14 months., Conclusion: We report on the 3 cases with the phenomenon of postoperative facet cysts and present a complication that falls within the spectrum of lumbar decompression surgery with several successful treatment options.

Case: We present the case of a 69-year-old man arriving to our clinic after a previous outside hospital recommendation of L1-S1 fusion due to degenerative scoliosis. A thoracic spine synovial cyst was identified through magnetic resonance imaging. The patient had rapid progression of his neurologic deficit due to cyst enlargement. We elected to perform cyst decompression and instrumented fusion of the involved thoracic segment. The patient rapidly regained full neurologic function. After the one-year follow-up, he remained asymptomatic with no progression of thoracolumbar degeneration., Conclusions: Thoracic spine synovial facet cysts are uncommonly encountered. Decompression alone or decompression and fusion are both viable treatment options depending on the surgeon's assessment of spine stability after decompression. This diagnosis should be considered in patients presenting with unilateral lower extremity upper motor neuron findings.

Purpose: Facet cysts develop due to degeneration of the zygapophyseal joints and can lead to radiculopathy and neurogenic claudication. Various surgical options are available for facet cyst excision. The aim was to facilitate surgical treatment of lumbar facet cysts based on a new classification., Methods: We retrospectively analyzed all patients of the last 10 years in whom a facet cyst was surgically removed (ipsilateral laminotomy, contralateral laminotomy, and segmental fusion). Several radiological parameters were analyzed and correlated with the patients' outcome (residual symptoms, perioperative complications, need for re-operation, need for secondary fusion, facet cyst recurrence)., Results: One hundred eleven patients (55 women; median age 64 years) could be identified. Thirty-three (48%) of 69 cases, for which MRI data were available, were classified as medial facet cyst (compressing the spinal canal), 6 facet cysts were localized intraforaminal (9%) and 30 cases (43%) mediolateral (combination of both). The contralateral approach had the lowest rate for revision surgery (7.5%, p = .038) and the lowest prevalence of residual complaints (7.5%, p = .109). A spondylolisthesis and a higher/steeper angle of the facet joints were associated with poorer patient outcome., Conclusions: Lateral facet joint cysts are best resected by a contralateral approach offering the best outcome while medial cysts are suitable for removal by an ipsilateral laminotomy. The approach of mediolateral cysts can be determined by the width of the lamina and the angle of the joint. Segmental fusion should be considered in cases with detected spondylolisthesis and/or steep facet joints.

Objective: Lumbar facet cysts are commonly seen in degenerative lumbar conditions causing stenosis and radiculopathy. Extraforaminal lumbar facet cysts are a rare entity and present a surgical challenge because of their location. Transforaminal endoscopic spine surgery is an emerging technique in spine surgery but has never been described as a treatment option for lumbar radiculopathy in the setting of extraforaminal lumbar facet cyst., Methods: A technique for the transforaminal endoscopic treatment of an extraforaminal lumbar facet cyst is presented in 2 patients. We retrospectively reviewed 321 cases of patients who underwent transforaminal endoscopic surgery in a 4-year period with a minimum follow-up of 2 years., Results: A series of 2 patients who underwent transforaminal endoscopic foraminotomy and cyst resection procedures for extraforaminal lumbar facet cysts between 2014 and 2017 is presented: A 51-year-old woman with a right L4-5 extraforaminal cyst improved from a preoperative visual analog scale (VAS) of 7 and Oswestry disability index (ODI) of 26 to a 1-year postoperative VAS score of 2 and ODI of 4; and a 71-year-old woman with a left L5-S1 extraforaminal cyst improved from a preoperative VAS of 7 and ODI of 30 to a 1-year postoperative VAS score of 2 and ODI of 6., Conclusions: Transforaminal endoscopic surgery for a lumbar radiculopathy in the setting of an extraforaminal lumbar facet cyst is presented as a unique minimally invasive approach for the treatment of extraforaminal lumbar facet cyst that avoids facet resection and fusion., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objectives: The treatments described for spinal synovial cysts range from percutaneous puncture to arthrodesis. There is a fear of postoperative instability after surgical resection of cysts, mainly when they are associated with degenerative spondylolisthesis. The objective of the article is to address the postoperative instability and recurrence rate of the symptoms after microsurgery without fusion., Methods: We report a consecutive series of 50 patients with lumbar synovial cysts operated on with microsurgery without arthrodesis. Functional status was assessed postoperatively by the MacNab success scale and by self-assessment using the Weiner scale, the 36-item short-form health survey (SF-36), and the Oswestry scale. The presence of preoperative and postoperative instability was determined with static and dynamic lumbar spine X-rays before surgery and in the last follow-up at 2 years to evaluate the presence of spondylolisthesis before and after surgery. Facet inclination angle and stage of disc degeneration at the level of the cysts were evaluated. Disc degeneration was defined by the modified Pfirrmann grading system., Results: The mean Oswestry index was 12 ± 12.6% (median 8, 0-53). Based on the MacNab scale, 98% were considered excellent and good. The Weiner scale showed that low back pain was present in 16% of patients postoperatively. There was significant improvement of leg strength and pain in 96% and 94%, respectively. Only 3 patients were reoperated on with late fusion. Total surgical resection was obtained in all cases, with a late fusion rate of only 6% and no recurrence at the operated site., Conclusions: The microsurgical treatment for synovial cysts without arthrodesis presented excellent and good results in the majority of cases. It is necessary to carry out prospective randomized studies to clarify the best therapeutic options., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Intraspinal synovial cyst (ISC) is a well-documented pathology. It is sometimes found in the degenerative lumbar spine and can result in neurological disorders. ISC typically contains xanthochromic fluid, blood, inflammatory tissue, and/or osseous structures, enclosed by fibrous tissue. Regarding the treatment modalities, the effectiveness of both nonsurgical management, such as oral analgesics, needle aspiration, and intra-articular injection of corticosteroid drugs, and surgical management, have been reported. Previous studies have described that the ISC can contain gas, which is derived from the vacuum phenomenon of an adjacent facet joint; however, this clinical condition has never been systematically investigated because of its rarity. In the present report, we describe the case of a 68-year-old male with gas-containing ISC in the lumbar spine who was successfully treated with surgical management; additionally, we performed a literature review to discuss the decision-making process for cases of gas-containing ISC. Based on our findings and previous literature, we recommend that considering the peculiarity of the content of such lesions in addition to the ball-valve effect of a synovial cyst, prompt transition to surgical management would be pertinent when nonsurgical treatment cannot achieve satisfactory outcomes in such cases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)