Microsurgical excision without fusion as a safe option for resection of synovial cyst of the lumbar spine: long-term follow-up in mono-institutional experience

Spontaneous Resolution of Symptomatic Synovial Cysts of the Lumbar Spine: A Comprehensive Review with Two Illustrative Cases

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.

Lumbar parafacetal cyst-spinal segmental instability is the cause and stabilization is the treatment: A clinical report of eight surgically-treated patients

Objective

The authors report the results of "only-fixation" of the affected spinal segment without any decompression of the bones or soft tissue or manipulation of the cyst wall or contents in eight cases having lumbar parafacetal cyst (LPFC). This surgical strategy was based on the concept that LPFCs are secondary to spinal instability, has a protective or adaptive role, and is reversible following stabilization.

Materials and Methods

During the period from January 2018 to January 2023, eight consecutive patients having LPFC were surgically treated. There were 5 males and 3 females, and their ages ranged from 48 to 72 years (average 63 years). Seven patients had a single cyst and one patient had multiple cysts. The patients presented with symptoms classically attributed to lumbar canal stenosis. Apart from the cyst-affected spinal segment, degenerative alterations were observed in adjoining spinal segments in six out of seven patients having a single cyst. All patients underwent "only fixation" of the unstable spinal segments without any kind of bone or soft-tissue resection and without any manipulation or handling of the cyst wall or contents.

Results

During the follow-up period that ranged from 12 to 57 months (average 29 months), all patients improved from their symptoms. The recovery was observed in the immediate postoperative period and was lasting.

Conclusions

LPFCs are one of the several secondary alterations observed in spinal degeneration. Identification of unstable spinal segments and their fixation constitutes rational treatment of lumbar parafacetal cysts. Direct handling and resection of cysts are unnecessary.

Decompression with or without Fusion for Lumbar Synovial Cysts—A Systematic Review and Meta-Analysis

The management of symptomatic lumbar synovial cysts (LSC) is still a matter of debate. Previous systematic reviews did not stratify data according to different treatment techniques or incompletely reported comparative data on patients treated with lumbar posterior decompression (LPD) and lumbar decompression and fusion (LDF). The aim of our study was to compare LPD and LDF via a systematic review and meta-analysis of the existing literature. The design of this study was in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The review questions were as follows: among patients suffering from symptomatic lumbar synovial cysts (population) and treated with either posterior lumbar decompression or posterior decompression with fusion (intervention), who gets the best results (outcome), in terms of cyst recurrence, reoperation rates, and improvement of postoperative symptoms (comparison)? The search of the literature yielded a total of 1218 results. Duplicate records were then removed (n = 589). A total of 598 articles were screened, and 587 records were excluded via title and abstract screening; 11 studies were found to be relevant to our research question and were assessed for eligibility. Upon full-text review, 5 were excluded because they failed to report any parameter separately for both LPD and LDF. Finally, 6 studies for a total of 657 patients meeting the criteria stated above were included in the present investigation. Our analysis showed that LDF is associated with better results in terms of lower postoperative back pain and cyst recurrence compared with LPD. No differences were found in reoperation rates and complication rates between the two techniques. The impact of minimally invasive decompression techniques on the different outcomes in LSC should be assessed in the future and compared with instrumentation techniques.

New classification of facet joint synovial cysts

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.

Coflex interspinous implant placement leading to synovial cyst development: case report

Interspinous process devices (IPDs) have been developed as less-invasive alternatives to spinal fusion with the goal of decompressing the spinal canal and preserving segmental motion. IPD implantation is proposed to treat symptoms of lumbar spinal stenosis that improve during flexion. Recent indications of IPD include lumbar facet joint syndrome, which is seen in patients with mainly low-back pain. Long-term outcomes in this subset of patients are largely unknown. The authors present a previously unreported complication of coflex (IPD) placement: the development of a large compressive lumbar synovial cyst. A 64-year-old woman underwent IPD implantation (coflex) at L4-5 at an outside hospital for low-back pain that occasionally radiates to the right leg. Postoperatively, her back and right leg pain persisted and worsened. MRI was repeated and showed a new, large synovial cyst at the previously treated level, severely compressing the patient's cauda equina. Four months later, she underwent removal of the interspinous process implant, bilateral laminectomy, facetectomy, synovial cyst resection, interbody fusion, and stabilization. At the 3-month follow-up, she reported significant back pain improvement with some residual leg pain. This case suggests that facet arthrosis may not be an appropriate indication for placement of coflex.

Lumbar ganglion cyst: Nosology, surgical management and proposal of a new classification based on 34 personal cases and literature review

AIM

To analyze different terms used in literature to identify lumbar extradural cysts and propose a common scientific terminology; to elaborate a new morphological classification of this pathology, useful for clinical and surgical purposes; and to describe the best surgical approach to remove these cysts, in order to avoid iatrogenic instability or treat the pre-existing one.

METHODS

We retrospectively reviewed 34 patients with symptomatic lumbar ganglion cysts treated with spinal canal decompression with or without spinal fixation. Microsurgical approach was the main procedure and spinal instrumentation was required only in case of evident pre-operative segmental instability.

RESULTS

The complete cystectomy with histological examination was performed in all cases. All patients presented an improvement of clinical conditions, evaluated by Visual Analogic Scale and Japanese Orthopaedic Association scoring.

CONCLUSION

Spinal ganglion cysts are generally found in the lumbar spine. The treatment of choice is the microsurgical cystectomy, which generally does not require stabilization. The need for fusion must be carefully evaluated: Pre-operative spondylolisthesis or a wide joint resection, during the operation, are the main indications for spinal instrumentation. We propose the terms “ganglion cyst” to finally identify this spinal pathology and for the first time its morphological classification, clinically useful for all specialists.

Synovial cysts of the spine: long-term follow-up after surgical treatment of 141 cases in a single-center series and comprehensive literature review of 2900 degenerative spinal cysts

OBJECTIVE Synovial cysts of the spine are rare lesions, predominantly arising in the lumbar region. Despite their generally benign behavior, they can cause severe symptoms due to compression of neural structures in the spinal canal. Treatment strategies are still a matter of discussion. The authors performed a single-center survey and literature search focusing on long-term results after minimally invasive surgery. METHODS A total of 141 consecutive patients treated for synovial cysts of the lumbar spine between 1997 and 2014 in the authors' department were analyzed. Medical reports with regard to signs and symptoms, operative findings, complications, and short-term outcome were reviewed. Assessment of long-term outcome was performed with a standardized telephone questionnaire based on the Oswestry Disability Index (ODI). Furthermore, patients were questioned about persisting pain, symptoms, and further operative procedures, if any. Subjective satisfaction was classified as excellent, good, fair, or poor based on the Macnab classification. RESULTS The approach most often used for synovial cyst treatment was partial hemilaminectomy in 70%; hemilaminectomy was necessary in 27%. At short-term follow-up, the presence of severe and moderate leg pain had decreased from 93% to 5%. The presence of low-back pain decreased from 90% to 5%. Rates of motor and sensory deficits were reduced from 40% to 14% and from 45% to 6%, respectively. The follow-up rate was 58%, and the mean follow-up period was 9.3 years. Both leg pain and low-back pain were still absent in 78%. Outcome based on the Macnab classification was excellent in 80%, good in 14%, fair in 1%, and poor in 5%. According to the ODI, 78% of patients had no or only minimal disability, 16% had moderate disability, and 6% had severe disability at the time of follow-up. In this cohort, 7% needed surgery due to cyst recurrence, and 9% required a delayed stabilization procedure after the initial operation. CONCLUSIONS Surgical treatment with resection of the cyst provides favorable results in outcome. Excellent or good outcome persisting for a long-term follow-up period can be achieved in the vast majority of cases. Complication rates are low despite an increased risk of dural injury. With facet-sparing techniques, the stability of the segment can be preserved, and resection of spinal synovial cysts does not necessarily require segmental fusion.

Evaluation and Treatment of Lumbar Facet Cysts

Lumbar facet cysts are a rare but increasingly common cause of symptomatic nerve root compression and can lead to radiculopathy, neurogenic claudication, and cauda equina syndrome. The cysts arise from the zygapophyseal joints of the lumbar spine and commonly demonstrate synovial herniation with mucinous degeneration of the facet joint capsule. Lumbar facet cysts are most common at the L4-L5 level and often are associated with spondylosis and degenerative spondylolisthesis. Advanced imaging studies have increased diagnosis of the cysts; however, optimal treatment of the cysts remains controversial. First-line treatment is nonsurgical management consisting of oral NSAIDs, physical therapy, bracing, epidural steroid injections, and/or cyst aspiration. Given the high rate of recurrence and the relatively low satisfaction with nonsurgical management, surgical options, including hemilaminectomy or laminotomy to excise the cyst and decompress the neural elements, are typically performed. Recent studies suggest that segmental fusion of the involved levels may decrease the risks of cyst recurrence and radiculopathy.

Postlaminectomy Bilateral Lumbar Intraspinal Synovial Cysts

Lumbar intraspinal synovial cysts are included in the difference diagnosis of lumbar radiculopathy. Developing imaging modalities has result in increased reporting about these lesions. However, the case of bilateral new lumbar intraspinal synovial cysts after laminectomy has been rarely reported. We report of a rare case with bilateral lumbar intraspinal synovial cysts after laminectomy, requiring surgical excision.

Minimally invasive resection of lumbar intraspinal synovial cysts via a contralateral approach: review of 13 cases

OBJECT

The authors sought to determine patient-related outcomes after minimally invasive surgical (MIS) lumbar intraspinal synovial cyst excision via a tubular working channel and a contralateral facet-sparing approach.

METHODS

All the patients with a symptomatic lumbar intraspinal synovial cyst who underwent surgery at the University of Iowa Hospitals and Clinics with an MIS excision via a contralateral approach were treated between July 2010 and August 2014. There was a total of 13 cases. Each patient was evaluated with preoperative neurological examinations, lumbar spine radiography, MRI, and visual analog scale (VAS) scores. The patients were evaluated postoperatively with neurological examinations and VAS and Macnab scores. The primary outcomes were improvement in VAS and Macnab scores. Secondary outcomes were average blood loss, hospital stay duration, and operative times.

RESULTS

There were 5 males and 8 females. The mean age was 66 years, and the mean body mass index was 28.5 kg/m2. Sixty-nine percent (9 of 13) of the cysts were at L4–5. Most patients had low-back pain and radicular pain, and one-third of them had Grade 1 spondylolisthesis. The mean (± SD) follow-up duration was 20.8 ± 16.9 months. The mean Macnab score was 3.4 ± 1.0, and the VAS score decreased from 7.8 preoperatively to 2.9 postoperatively. The mean operative time was 123 ± 30 minutes, with a mean estimated blood loss of 44 ± 29 ml. Hospital stay averaged 1.5 ± 0.7 days. There were no complications noted in this series.

CONCLUSIONS

The MIS excision of lumbar intraspinal synovial cysts via a contralateral approach offers excellent exposure to the cyst and spares the facet joint at the involved level, thus minimizing risk of instability, blood loss, operative time, and hospital stay. Prospective randomized trials with longer follow-up times and larger cohorts are needed to conclusively determine the superiority of the contralateral MIS approach over others, including open or ipsilateral minimally invasive surgery.

Midline synovial and ganglion cysts causing neurogenic claudication

Typically situated posterolateral in the spinal canal, intraspinal facet cysts often cause radicular symptoms. Rarely, the midline location of these synovial or ganglion cysts may cause thecal sac compression leading to neurogenic claudication or cauda equina syndrome. This article summarizes the clinical presentation, radiographic appearance, and management of three intraspinal, midline facet cysts. Three patients with symptomatic midline intraspinal facet cysts were retrospectively reviewed. Documented clinical visits, operative notes, histopathology reports, and imaging findings were investigated for each patient. One patient presented with neurogenic claudication while two patients developed partial, subacute cauda equina syndrome. All 3 patients initially responded favorably to lumbar decompression and midline cyst resection; however, one patient required surgical stabilization 8 mo later. Following the three case presentations, we performed a thorough literature search in order to identify articles describing intraspinal cystic lesions in lateral or midline locations. Midline intraspinal facet cysts represent an uncommon cause of lumbar stenosis and thecal sac compression. Such entities should enter the differential diagnosis of midline posterior cystic lesions. Midline cysts causing thecal sac compression respond favorably to lumbar surgical decompression and cyst resection. Though laminectomy is a commonly performed operation, stabilization may be required in cases of spondylolisthesis or instability.

The diagnosis and management of synovial cysts: Efficacy of surgery versus cyst aspiration

Background:

The surgical management of lumbar synovial cysts that have extruded into the spinal canal remains controversial (e.g. decompression with/without fusion).

Methods:

The neurological presentation, anatomy, pathophysiology, and surgical challenges posed by synovial cysts in the lumbar spine are well known. Neurological complaints typically include unilateral or, more rarely, bilateral radicular complaints, and/or cauda equina syndromes. Anatomically, synovial cysts constitute cystic dilatations of synovial sheaths that directly extrude from facet joints into the spinal canal. Pathophysiologically, these cysts reflect disruption of the facet joints often with accompanying instability, and potentially compromise both the cephalad and caudad nerve roots.

Results:

Aspiration of lumbar synovial cysts, which are typically gelatinous and non-aspirable, and typically performed by “pain specialists” (e.g. pain management, rehabilitation, radiologists, others) utilizing fluoroscopy or CT-guided aspiration, is associated with 50–100% failure rates. Surgical decompression with/without fusion (as the issue regarding fusion remains unsettled) results in the resolution of back and radicular pain in 91.6–92.5% and 91.1–91.9% of cases, respectively.

Conclusions:

After a thorough review of the literature, it appears that the treatment with the best outcome for patients with synovial cysts is cyst removal utilizing surgical decompression; the need for attendant fusion remains unsettled. The use of an alternative treatment, percutaneous aspiration of cysts, appears to have a much higher recurrence and failure rate, but may be followed by surgery if warranted.