Should We Label All Synovial Cysts as Unstable?

Outcomes and adverse events for spinal synovial cysts surgical treatment: a systematic review and meta-analysis

BACKGROUND

Spinal synovial cysts (SSCs) are a rare cause of nerve root and spinal cord compression. Surgical excision of SSCs remains the mainstay of treatment in the presence of unremitting symptoms or neurological deficits, but the choice of the surgical approach remains controversial. The goal of this study was to compare clinical outcomes and adverse events associated with traditional approaches (interlaminar or laminectomy/hemilaminectomy) and minimally invasive approaches (microsurgical tubular approaches or endoscopic approaches) for SSCs.

METHODS

Studies reporting surgical management of SSCs were searched in three online databases (PubMed, the Cochrane Library, and Web of Science). This meta-analysis was reported following the PRISMA Statement. It was registered at the International Prospective Register of Systematic Reviews (CRD42021288992). The Cochrane Collaboration's Risk of Bias in Nonrandomised Studies-of Interventions (ROBINS-I) was used to evaluate bias. Extracted research data were statistically analyzed using Stata 16 and SPSS statistics 25.

RESULTS

A total of 22 related relevant studies were included. Meta-analysis revealed no statistically significant difference in dural tear, residual cyst, recurrence, reoperation, and operation time between minimally invasive approaches and traditional approaches (p > 0.05), but minimally invasive approaches had a good functional improvement (p = 0.004). Postoperative length of hospital stays and intraoperative bleeding in traditional approaches were also higher than in minimally invasive approaches (p < 0.05).

CONCLUSION

Based on the available evidence, minimally invasive approaches may be better than traditional approaches in the treatment of SSCs. Minimally invasive approaches had the advantages of improving clinical satisfaction, with a similar complication rate to traditional approaches. Moreover, endoscopic and microsurgical tubular approaches had similar outcomes.

Significance of Facet Fluid Index in Anterior Cervical Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To correlate cervical facet fluid characteristics to radiographic spondylolisthesis, determine if facet fluid is associated with instability in cervical degenerative spondylolisthesis, and examine whether vertebral levels with certain facet fluid characteristics and spondylolisthesis are more likely to be operated on.

OVERVIEW OF LITERATURE

The relationship between facet fluid and lumbar spondylolisthesis is well-documented; however, there is a paucity of literature investigating facet fluid in degenerative cervical spondylolisthesis.

METHODS

Patients diagnosed with cervical degenerative spondylolisthesis were identified from a hospital's medical records. Demographic and surgical characteristics were collected through a structured query language search and manual chart review. Radiographic measurements were made on preoperative MRIs for all vertebral levels diagnosed with spondylolisthesis and adjacent undiagnosed levels between C3 and C6. The facet fluid index was calculated by dividing the facet fluid measurement by the width of the facet. Bivariate analysis was conducted to compare facet characteristics based on radiographic spondylolisthesis and spondylolisthesis stability.

RESULTS

We included 154 patients, for whom 149 levels were classified as having spondylolisthesis and 206 levels did not. The average facet fluid index was significantly higher in patients with spondylolisthesis (0.26±0.07 vs. 0.23±0.08, p <0.001). In addition, both fluid width and facet width were significantly larger in patients with spondylolisthesis (p <0.001 each). Cervical levels in the fusion construct demonstrated a greater facet fluid index and were more likely to have unstable spondylolisthesis than stable spondylolisthesis (p <0.001 each).

CONCLUSIONS

Facet fluid index is associated with cervical spondylolisthesis and an increased facet size and fluid width are associated with unstable spondylolisthesis. While cervical spondylolisthesis continues to be an inconclusive finding, vertebral levels with spondylolisthesis, especially the unstable ones, were more likely to be included in the fusion procedure than those without spondylolisthesis.

Percutaneous uniportal full-endoscopic surgery for treating symptomatic lumbar facet joint cysts under local anesthesia combined with monitored anesthesia care: a preliminary report of eight cases with at least 1 year follow-up

Background

Lumbar facet joint cysts (FJCs) are a relatively rare clinical pathology that can result in radiculopathy or neurogenic claudication. Various treatments such as percutaneous aspiration and surgery have been reported to have good clinical outcomes. However, few clinical studies have aimed to treat symptomatic lumbar FJCs by using uniportal full-endoscopic (UFE) surgery. This study aimed to investigate the preliminary clinical outcomes of UFE surgery for the treatment of lumbar FJCs under local anesthesia combined with monitored anesthesia care (MAC).

Methods

Eight patients (five males and three females) with symptomatic lumbar FJCs who underwent UFE surgery under local and MAC anesthesia were enrolled in this study between January 2018 and April 2022. The clinical characteristics, radiological features, operative information, visual analog scale (VAS) score, Oswestry disability index (ODI), and overall outcome rating based on the modified MacNab criteria were retrospectively analyzed.

Results

Of the eight patients, four underwent a transforaminal approach and four underwent an interlaminar approach. Postoperatively, the mean VAS score for leg pain decreased from 6.1 before surgery to 0.6 after surgery, and the ODI decreased from 74.5% to 14.7%. All patients were followed up for more than 1 year, and the good-to-excellent rate based on the modified MacNab criteria remained 100% at the last follow-up. No complications occurred during the follow-up period.

Conclusion

Lumbar FJCs can cause severe radiating leg pain and/or neurogenic claudication due to the dural sac compression and nerve roots. As an alternative treatment, UFE decompression under local and MAC anesthesia may provide effective clinical outcomes for symptomatic lumbar FJCs.

Creation and validation of a predictive model for lumbar synovial cyst recurrence following decompression without fusion

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.

Five-Year Outcomes After Decompression and Fusion Versus Decompression Alone in the Treatment of Lumbar Synovial Cysts

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.

Cervical facet joint effusion: A sign of instability in cervical degenerative spondylolisthesis

Aims:

The aim of this study was to trace the association between cervical facet joint effusion and cervical degenerative spondylolisthesis (CDS). CDS has not received as much attention as its lumbar counterpart. Identification of features of instability on magnetic resonance imaging (MRI) is crucial to avoid missing presence of CDS.

Materials and Methods:

The authors retrospectively reviewed cervical spine MRI scans and upright lateral flexion-extension radiographs of 17 consecutive patients at a single institution between January 2017 and June 2018 that revealed CDS. Presence of cervical facet joint effusion and CDS was recorded. Data were analyzed to deduce possibility of an association between cervical facet joint effusion and CDS.

Results:

Seventeen patients fulfilled the inclusion criteria of cervical spondylotic myelopathy associated with CDS. Out of these, 10 patients revealed facet joint effusion at C3-C4 (4 patients) and C4-C5 (6 patients) levels. The mean age of patients was 65.8 years (49–79) and M:F was 2.2:1. Amount of facet joint effusion varied and ranged from 1.6 mm to 4.7 mm on the axial images. Ten patients (58.82%) demonstrated facet joint effusion associated with mobile CDS. Seven patients (41.17%) with CDS and without facet effusion did not demonstrate mobility of more than 0.5 mm in flexion-extension radiographs.

Conclusion:

The current study acknowledges the association of “cervical facet effusion” and CDS. Clinically measurable facet joint effusion on MRI suggests the need for further attempts to diagnose CDS.

The Fate of Lumbar Facet Cyst After Indirect Decompression Using Oblique Lateral Interbody Fusion in Degenerative Spondylolisthesis

Favorable clinical outcomes have been reported for oblique lateral interbody fusion (OLIF) for various lumbar degenerative diseases. However, there is only limited evidence on the safety and effectiveness of OLIF in degenerative spondylolisthesis with lumbar facet cyst (LFC), and OLIF is often regarded as a relative contraindication for these patients. The authors prospectively enrolled patients who underwent a single-level OLIF for degenerative spondylolisthesis with LFC to evaluate the morphological changes of LFC and their clinical significance following OLIF. Twenty patients with a mean age of 69.6 years (range, 65-86 years) were enrolled. At 1 week postoperative, 5 (25%) patients had a residual cyst, whereas 15 (75%) patients had completely resolved cysts on magnetic resonance imaging (MRI). No patient had a residual cyst on the 1-year postoperative MRI. Patients with cyst resolution (n=15) on the 1-week postoperative MRI had a larger slip percentage difference on the preoperative dynamic radiograph when compared with patients with no cyst resolution (n=5) (4.7%±2.8% vs 1.3%±0.3%, P=.002). The group with cyst resolution also showed a greater expansion of facet fluid width following OLIF, although this was not statistically significant (1.2±0.7 mm vs 0.7±0.5 mm, P=.098). For both groups, all preoperative clinical scores showed a significant improvement at 1 year after OLIF, but there was no significant difference between the groups at all time points. Preliminary 1-year follow-up results from this prospective series suggest that OLIF can be a useful option for fusion surgery in LFC patients with apparent segmental instability. [Orthopedics. 2021;44(5):306-312.].

Classification and Reliability of Lumbar Facet Cysts Grading Scales

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.

Outcomes and complications following minimally invasive excision of synovial cysts of the lumbar spine: A systematic review and meta-analysis

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, I² 82%). The pooled percentage change in visual analogue scale (VAS) after surgery was 76.5% (95% CI 66.9-84%, I² 82%). The pooled proportion of incidental durotomies, cyst recurrence and patients requiring operation being 8% (95% CI 5-11%, I² 0%), 4% (95% CI 2-7%, I² 0%,) and 5% (95% CI 3-9%) respectively. Studies were homogeneous with an I² 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.

A Practical Approach to Spine Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) plays an important role in the evaluation of patients with spine disorders, providing excellent evaluation of both normal and pathologic anatomy. Interpreting MRI findings can be difficult as anatomic abnormalities may not correlate with clinical symptoms and MRI may show abnormal findings in asymptomatic individuals. Using a systematic approach to interpreting a spinal MRI can help to achieve an accurate diagnosis and guide therapeutic decision-making, surgical intervention, and treatment monitoring.

Comparison of Decompression versus Decompression and Fusion for Lumbar Synovial Cysts and Predictive Factors for Cyst Recurrence

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 χ² 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.

Rapid Neurologic Deterioration due to an Enlarging Thoracic Spine Synovial Cyst: A Case Report

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.

[Minimally invasive resection of spinal synovial cysts: Technical note]

Objetivo:

Presentar el algoritmo de tratamiento, técnica quirúrgica y resultados de una serie de pacientes con quistes sinoviales espinales resecados con técnica mínimamente invasiva (MIS).

Introducción:

Los quistes sinoviales espinales se originan a partir de la dilatación y potencial ruptura de la vaina sinovial de una articulación facetaria, la resección quirúrgica es considerada el tratamiento de elección en pacientes sintomáticos. La utilización de técnicas MIS podrían disminuir la disrupción de la faceta articular comprometida reduciendo el riesgo de inestabilidad postoperatoria.

Material y métodos:

Se evaluaron retrospectivamente 21 pacientes con quistes sinoviales espinales operados mediante abordaje y descompresión MIS, se analizaron los signos, síntomas, tiempo quirúrgico, estadía hospitalaria, evolución y complicaciones. Se utilizó la escala visual analógica (EVA), para evaluar el dolor y la escala de Weiner y los criterios de Macnab modificados para medir la satisfacción posoperatoria del paciente.

Resultados:

Se trataron quirúrgicamente 21 pacientes (13 mujeres, 8 hombres), el 76,2% (n = 16) de los pacientes de la serie no requirió artrodesis, el 23,8% (n = 5) restante fue fusionado. Realizamos 13 (61,9%) hemilaminectomías contralaterales, 7 hemilaminectomías ipsilaterales (33,3%) y una laminectomía en el QS S1-S2 con técnica MIS. El seguimiento promedio fue de 26 meses, el tiempo de cirugía fue de 150,33 ± 63,31 min., con una estadía hospitalaria de 2,5 ± 1,78 días. La EVA disminuyó de 8,3 preoperatoria a 2,3 postoperatoria. Siguiendo la escala de Macnab; 16 pacientes refirieron resultados excelentes, 4 buenos y 1 regular, el 95,2% de los pacientes percibió que el procedimiento tuvo mucho/bastante éxito según la escala de Weiner.

Conclusión:

El abordaje mínimamente invasivo es un procedimiento seguro y eficaz para la resección completa de quistes sinoviales espinales. Proporciona resultados clínico-funcionales excelentes preservando músculos, ligamentos y facetas articulares.