A synovial cyst-induced vertebral artery dissection in bow hunter's stroke: illustrative case.

BACKGROUND: Bow hunter's stroke (BHS) is a rare condition characterized by occlusion of the vertebral artery (VA) due to a head rotation. BHS typically results from neck hyperrotation, often due to anatomical factors. The authors present a case of BHS in a young male patient exacerbated by os odontoideum (OD), resulting in atlantoaxial dislocation, which ultimately led to VA dissection. OBSERVATIONS: A man in his 20s presented with persistent dizziness and nausea and initially received a diagnosis of a brain infarction. However, imaging revealed VA dissection caused by an OD with an associated synovial cyst. Surgical intervention, specifically atlantoaxial posterior fixation, resolved the instability and allowed for natural regression of the synovial cysts, preventing further vascular events. In this case, the OD with atlantoaxial dislocation was identified as the causative factor for BHS. The coexistence of a synovial cyst was a unique finding, likely triggered by chronic irritation caused by the OD. LESSONS: This case emphasizes the importance of thorough cervical spinal evaluation in young patients presenting with posterior circulation stroke. https://thejns.org/doi/10.3171/CASE2487.

A challenge diagnosis of lumbar synovial facet cyst. A case report.

INTRODUCTION AND IMPORTANCE: Synovial cysts occur more frequently in the lumbar spine, especially at L4-5 level. Traditional open surgical management with posterolateral arthrodesis is the currently recommended treatment. CASE PRESENTATION: This is a 64-year-old woman with no prior pathological history. Initial clinical and radiological assessment concluded that there was advanced right coxarthrosis with a degenerative lumbar spine. The patient therefore had a total hip arthroplasty secondarily presented an intermittent neurogenic claudication without sphincter disorders. The MRI concluded at a compressive synovial facet cyst at the L4-L5 level. The patient underwent surgical treatment. At two years postoperatively, the walking distance was significantly improved while maintaining moderate lower back pain. CLINICAL DISCUSSION: The diagnosis of synovial facet cysts of spine is a challenge that depends heavily on history, physical examination, and MRI. MRI will demonstrate not only the nature of the cystic lesion, but also its relationship to the root, the cord or the thecal sac. The L4-L5 level of the lumbar spine is the most common location of the synovial cyst of the facet joints. As in our case, surgical treatment combining posterolateral arthrodesis is currently recommended for these types of lesions. Surgical treatment, as in our case, is sometimes delayed when this pathology is associated with advanced osteoarthritis of the hips. CONCLUSION: Improved imaging capabilities such as magnetic resonance imaging (MRI) have resulted in increased reporting, diagnostic yield and treatment of spinal synovial cysts. Surgical treatment combining posterolateral arthrodesis is the treatment for this lesion.

Synovial Cyst of the extensor digitorum superficialis: A case report.

Background: A synovial cyst is a herniation of synovial tissue through a joint capsule, often mistaken for a ganglion cyst. The key distinctions are that synovial cysts have a synovial cell lining, while a ganglion cyst is delineated by dense fibrous connective tissue. Typically found near joints, synovial cysts are associated with conditions like osteoarthritis, prevalent in females aged 20 to 50. We present a rare case of a synovial cyst in the extensor digitorum superficialis of the right hand. Case summary: A 53-year-old Hispanic female visited our hand clinic due to a 3-year history of pain on the back of her right hand. At exploration, a 3 × 3 cm soft tumor was identified. Surgery revealed a clear-yellowish mass within the extensor digitorum superficialis tendon. Following the surgery, synovial cyst was confirmed by pathology and the patient was discharged without complications. Conclusion: This case highlights the rare presentation of an intratendinous synovial cyst and emphasizes the importance of a comprehensive understanding of synovial cysts in the differential diagnosis of hand tumors.

Arthroscopy-assisted Procedures in Hand and Wrist Surgery: An Update. Where Are We So Far?

Wrist and hand arthroscopy, despite being an old tool, has gained popularity and advanced in assisting in the treatment of various injuries and conditions in the region in recent years. Dorsal, volar, ulnar, and radial accessory portals are used to reach all points of the carpal and hand joints. The minimal tissue damage, lesser injury to the capsule and its mechanoreceptors, the assessment of injuries associated with the reason for surgery, and aesthetically more favorable scars have attracted many doctors and their patients. As a result, there has been an increase in publications and diversifications of arthroscopic techniques. The aim of this update article is to present the advances and the evidence available in the literature to assist readers in their decision on which technique to use in the treatment of wrist and hand conditions.

Evaluation and Treatment of Lumbar Spine Extradural Cysts: A Narrative Review.

The main objective was to describe the different types and characteristics of lumbar spine extradural cysts and their optimal treatment options with a focus on endoscopic technique. We searched Pubmed, EMBASE, Medline, and Google Scholar for articles published between 1967 and 2020 using the keywords "Spinal Cyst," "Extradural Cyst," and "Lumbar Cyst." The various anatomical and histological types of the extradural cysts with their presentations, etiologies, imaging, and optimal treatment with a focus on endoscopic techniques were reviewed from the articles. Lumbar spinal cysts are relatively rare pathologies that might cause radicular symptoms similar to lumbar disc herniation. Spinal extradural cysts are classified either histologically based on the cyst lining tissues (synovial cysts or non-synovial, ganglion cysts) or anatomically based on the structure of origin (epidural cysts, ligamentum flavum cysts, discal cysts, post-discectomy pseudocysts, posterior longitudinal ligament cysts, facet cysts). Surgical excision is the recommended treatment of symptomatic cysts with endoscopic techniques being a viable option. Extradural lumbar cysts can be identified based on their histological structure or depending on their structure of origin. Regardless of their classification, they could all give similar clinical findings, and the optimal treatment would be surgical excision with endoscopic technique being a viable option with a satisfactory outcome.

Arthroscopy-assisted Procedures in Hand and Wrist Surgery: An Update. Where Are We So Far? / Procedimentos assistidos por artroscopia no punho e na mão: Atualização. Onde nós estamos?

Abstract Wrist and hand arthroscopy, despite being an old tool, has gained popularity and advanced in assisting in the treatment of various injuries and conditions in the region in recent years. Dorsal, volar, ulnar, and radial accessory portals are used to reach all points of the carpal and hand joints. The minimal tissue damage, lesser injury to the capsule and its mechanoreceptors, the assessment of injuries associated with the reason for surgery, and aesthetically more favorable scars have attracted many doctors and their patients. As a result, there has been an increase in publications and diversifications of arthroscopic techniques. The aim of this update article is to present the advances and the evidence available in the literature to assist readers in their decision on which technique to use in the treatment of wrist and hand conditions.

Resumo A artroscopia de punho e mão, apesar de ser uma ferramenta antiga, tem ganhado popularidade e avançado no auxílio do tratamento das mais diversas lesões e doenças da região nos últimos anos. Utilizam-se portais acessórios dorsais, volares, ulnares e radiais para se alcançar todos os pontos das articulações do carpo e da mão. O menor dano tecidual, a menor lesão da cápsula e de seus mecanoceptores, a avaliação de lesões associadas ao motivo da cirurgia e as cicatrizes esteticamente mais favoráveis têm atraído muitos médicos e seus pacientes. Com isso, houve um aumento das publicações e diversificações de técnicas artroscópicas. O objetivo deste artigo de atualização é mostrar os avanços e o que temos de evidência na literatura para apoiar os leitores na sua decisão sobre qual técnica utilizar nos tratamentos das doenças do punho e da mão.

Cystic soft tissue tumours of the dorsal aspect of the wrist have two distinct histological subtypes.

In total, 38 patients with cystic dorsal wrist tumours managed with surgical excision were prospectively followed up for 2 years. Tissue was examined histologically after primary surgery and at recurrence. Two distinct tissue types were found: ganglion cyst and synovial cyst.

Full endoscopic resection of large bilateral synovial cysts in lumbar spine.

Synovial spinal cysts cause radiculopathy and back pain, with rare reports of cauda equina syndrome. Hypermobility and instability are cornerstones for synovial cyst formation. The incidence is around 5%, and data for bilateral cysts are lacking. Surgery is indicated after conservative measures fail. Recurrence is common and is potentially due to joint violation and destabilization from open surgery. This could be prevented via ultra-minimally invasive approaches. The authors present full endoscopic removal of bilateral synovial cysts in a patient with grade 1 stable spondylolisthesis and include a 360° view for confirmation of complete decompression. Postoperatively, the patient reported immediate pain relief. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23208.

Conservative treatment of a synovial cyst in a golden eagle (Aquila chrysaetos) with triamcinolone acetonide.

In human and veterinary medicine, the treatment of synovial cysts involves medical or surgical approach. When medical treatment is chosen, triamcinolone acetonide is one of the most used drugs. In this case, intracystic triamcinolone was administered for the treatment of a non-infectious elbow synovial cyst in a subadult female Golden eagle (Aquila chrysaetos), unable to fly. The bird was brought to a wildlife rescue center after an aerial fight with a conspecific. After the treatment, no clinically detectable adverse effects were noted and there was no recurrence within two weeks. Given the improvement of the clinical conditions and the recovery of flight ability, the animal was released back into the wild 17 days after administration of the drug.

Articular arthrodesis with the facet wedge technique for the treatment of unstable lumbar degenerative disease and associated conditions: A retrospective study of 96 patients.

Background: Lumbar articular fusion with the facet wedge (FW) technique is gaining increasing interest among surgeons for the treatment of vertebral instability due to its limited invasiveness and ease of use. Studies on cadavers have reported biomechanical properties similar to pedicle screws. Yet, the evidence supporting their use is still limited and moreover focused only on spinal degenerative disease. Methods: 96 cases of lumbar articular fusion with the FW techniques performed at 3 different centers between 2014 and 2022 were retrospectively analyzed based on the specific surgical indications: 1) degenerative spondylolisthesis/unstable lumbar stenosis; 2) synovial cysts; 3) adjacent segment disease (ASD). Medical records were reviewed to identify rates of complications and measures of functional outcome (ODI, low back pain VAS and modified Macnab scale) were collected both at baseline and at the follow-up visits. Wilcoxon signed-rank test was adopted to test for significant functional improvements. Results: Significative clinical improvements were observed from baseline to follow-up regarding ODI and VAS scores. Overall rate of moderate and severe complications (according to Landriel-Ibañez scale) was 7.9%. Only 3.4% of patients with degenerative disease developed ASD requiring reoperations. Only one case of radicular deficit and one of device mobilization were reported. 2/4 cases of synovial cysts treated with unilateral fusions developed contralateral complications. 9 out of 16 (56.25%) patients who underwent long-term postoperative CT scans presented adequate degree of articular fusion. Conclusion: FW technique is easy, safe, and effective. Its low rate of complications justifies its use for cases of mild lumbar instability.

Spinal calcifying pseudoneoplasm of the neuraxis (CAPNON) associated with facet joint pathologies: CAPNON diagnostic and pathogenic insights.

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumor-like fibro-osseous lesion that can develop anywhere in the neuraxis. Approximately a half of reported CAPNONs developed in the spinal region, mostly close to the facet joint (FJ). The diagnosis of spinal CAPNONs is challenging given the existence of mimics and associated pathologies including calcific degeneration of the FJ ligaments (DFJL) and synovial cysts (SCs). The pathogenesis of CAPNON remains elusive, although there have been a few hypotheses including degenerative, reactive, proliferative and immune-mediated processes. Our present study examined clinical, radiological and pathological features of 12 spinal CAPNONs in comparison to 9 DFJL foci, and diagnostic and pathogenic relationship between CAPNONs and FJ pathologies. On imaging, CAPNONs were all tumor-like and typically bigger than DFJL foci. All CAPNONs showed pathologically diagnostic features including characteristic cores, consistently identifiable core-surrounding/peripheral palisading of macrophages and other cells including multinucleated giant cells, variable infiltration of CD8+ T-cells, and multifocal immunopositivity of neurofilament light chain (NF-L). These features were absent or limited in the DFJL foci with statistically significant differences from CAPNONs, except calcifications. Spinal CAPNONs co-existed with DFJL foci in all cases; some had transitional foci with overlapping focal CAPNON and DFJL-like features. These findings, along with our previously reported relationship between CAPNONs and SCs, suggest that spinal CAPNONs may occur in association with or in transition from calcifying/calcified degenerative lesions of FJ ligaments and/or SCs when a reactive proliferative process is complemented by other pathogenic changes such as immune-mediated pathology and NF-L deposition/expression.

Evolution of lumbar degenerative spondylolisthesis with key radiographic features.

Spondylolisthesis is a common finding in middle-aged and older adults with back pain. The pathophysiology of degenerative spondylolisthesis is a subject of controversy regarding not only its etiology but also the mechanisms of its progression. It is theorized that degeneration of the facets and discs can lead to segmental instability, leading to displacement over time. Kirkaldy-Willis divided degenerative spondylolisthesis into three phases: dysfunction, instability, and finally, restabilization. There is a paucity of literature on the unification of the radiological hallmarks seen in spondylolisthesis within these phases. The radiographic features include (1) facet morphology/arthropathy, (2) facet effusion, (3) facet vacuum, (4) synovial cyst, (5) interspinous ligament bursitis, and (6) vacuum disc as markers of dysfunction, instability, and/or restabilization. We discuss these features, which can be seen on X-ray, CT, and MRI, with the intention of establishing a timeline upon which they present clinically. Spondylolisthesis is initiated as either degeneration of the intervertebral disc or facet joints. Early degeneration can be seen as facet vacuum without considerable arthropathy. As the vertebral segment becomes increasingly dynamic, fluid accumulates within the facet joint space. Further degeneration will lead to the advancement of facet arthropathy, degenerative disc disease, and posterior ligamentous complex pathology. Facet effusion can eventually be replaced with a vacuum in severe facet osteoarthritis. Intervertebral disc vacuum continues to accumulate with further cleft formation and degeneration. Ultimately, autofusion of the vertebra at the facets and endplates can be observed. With this review, we hope to increase awareness of these radiographical markers and their timeline, thus placing them within the framework of the currently accepted model of degenerative spondylolisthesis, to help guide future research and to help refine management guidelines.

Facet joint disorders: from diagnosis to treatment.

One of the most common sources of spinal pain syndromes is the facet joints. Cervical, thoracic, and lumbar facet joint pain syndromes comprise 55%, 42%, and 31% of chronic spinal pain syndromes, respectively. Common facet joint disorders are degenerative disorders, such as osteoarthritis, hypertrophied superior articular process, and facet joint cysts; septic arthritis; systemic and metabolic disorders, such as ankylosing spondylitis or gout; and traumatic dislocations. The facet pain syndrome from osteoarthritis is suspected from a patient's history (referred pain pattern) and physical examination (tenderness). Other facet joint disorders may cause radicular pain if mass effect from a facet joint cyst, hypertrophied superior articular process, or tumors compress the dorsal root ganglion. However, a high degree of morphological change does not always provoke pain. The superiority of innervating nerve block or direct joint injection for diagnosis and treatment is still a controversy. Treatment includes facet joint injection in facet joint osteoarthritis or whiplash injury provoking referred pain or decompression in mass effect in cases of hypertrophied superior articular process or facet joint cyst eliciting radicular pain. In addition, septic arthritis is treated using a proper antibiotic, based on infected tissue or blood culture. This review describes the diagnosis and treatment of common facet joint disorders.

Successful treatment of facet joint synovial cyst through percutaneous rupture: a case report.

Facet joint synovial cysts can cause significant back pain and radiculopathy. Treatment options for symptomatic facet joint synovial cysts include surgical excision, facet joint steroid injections, and cyst aspiration. Herein, we report our experience of successfully rupturing a lumbar facet joint synovial cyst through a percutaneous approach with two needles using forceful pressure under C-arm fluoroscopic guidance. The patient experienced immediate symptom improvement that persisted throughout the 24-month follow-up. Our experience highlights that the volume effect technique is a valuable treatment option for symptomatic facet joint synovial cysts under fluoroscopic guidance.

Management of rare atlantoaxial synovial cyst case with extension to the cerebellopontine angle: illustrative case.

BACKGROUND: Synovial cysts are a common finding in degenerative spine disease, most frequently involving the facet joints of the lumbar spine. Synovial cysts are less common in the cervical spine and rarely involve the atlantoaxial junction. OBSERVATIONS: In this case report, the authors detail a unique presentation of a left atlantoaxial synovial cyst with large intracranial extension into the cerebellopontine angle causing progressive cranial nerve palsies resulting in tinnitus, vertigo, diminished hearing, gait imbalance, left trigeminal hypesthesia, left facial weakness, and dysarthria. The patient underwent a retromastoid craniectomy for resection of the synovial cyst, resulting in improvement and resolution of symptoms. Follow-up occurred at 6 weeks, 3 months, and 5 months postoperatively without recurrence on imaging. LESSONS: The authors describe acute and long-term management of a unique presentation of an atlantoaxial synovial cyst including retromastoid craniectomy, intervals for follow-up for recurrence, and possible treatment options in cases of recurrence. A systematic literature review was also performed to explore all reported cases of craniocervical junction synovial cysts and subsequent surgical management.

Extradural lumbar arteriovenous fistula imitating a synovial cyst: illustrative case.

BACKGROUND: Spinal dural arteriovenous fistula is the most common spinal vascular malformation. It usually presents with neurological deficits due to venous congestive myelopathy. Sometimes, however, the symptoms are radicular and can imitate those of a disc hernia or synovial cyst. OBSERVATIONS: In this illustrated case, a 34-year-old male patient presented with radicular pain due to nerve root compression. In the magnetic resonance imaging (MRI) examination of the spine, a synovial cyst was suspected, so the patient underwent no further examination before surgery. Intraoperatively, the authors were surprised to see a vascular malformation, which was shown to be an extradural arteriovenous fistula according to the histopathological examination. LESSONS: In atypical MRI findings of the spine, vascular malformations should be considered. In cases with a spinal dural arteriovenous fistula, the thrombosis risk can be high and lead to a need for prolonged anticoagulation.

Synovial Cyst in the Setting of an Interspinous Fusion Device.

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.

Simple Microsurgical Extirpation as a Method of Choice in Treating Symptomatic Spinal Facet Joint Cysts: A Retrospective Case Series.

BACKGROUND: Facet joint cysts (FJCs) are a cause of radiculopathy, back pain, cauda equina syndrome, and/or claudication. They mostly affect the lumbar spine in the elderly, prevailing in women, and are connected to spinal degeneration and instability. We aimed to evaluate the safety and efficacy of open surgical decompression and cyst excision without a subsequent fusion. METHODS: We evaluated neurologic symptoms and potential signs of spinal instability on preoperative versus postoperative radiological examination. We performed a histological assessment of the extirpated cysts. Statistical analysis was then performed. RESULTS: Of a total of 66 patients, 44 were included in the present study. The average age was 61.2 years. Female patients prevailed (61.4%). The mean follow-up was 5.3 years. The segment most frequently affected by a FJC was L4-L5 (65.9%). Cyst resection led to significant relief from neurologic symptoms for most patients. Thus, 95.5% of our patients reported their postoperative outcome as excellent. Preoperatively, 43.2% and 47.4% of patients had had radiographic signs of instability on magnetic resonance imaging and signs of spondylolisthesis on dynamic radiographs in the operated segment, respectively, with 54.5% manifesting signs of spondylolisthesis in the same segment on a postoperative dynamic radiograph. Despite spondylolisthesis progression, no patient required reoperation. Histologically, pseudocysts without synovium were more frequent than were synovial cysts. CONCLUSIONS: Simple FJC extirpation is a safe and effective method for resolving radicular symptoms, with excellent long-term outcomes. It does not lead to the development of clinically significant spondylolisthesis in the operated segment; thus, no supplementary fusion with instrumented stabilization is required.

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.

A rare gas-containing lumbar synovial cyst treated by percutaneous transforaminal endoscopic cystectomy: A case report and literature review.

Spinal synovial cysts are rare entities for which standard surgical strategies are inconsistent. Here, we present an uncommon intraspinal gas-containing synovial cyst treated by percutaneous transforaminal endoscopic cystectomy. A 52-year-old man presented with radicular pain and intermittent claudication that had persisted for one month. Computed tomography revealed an intraspinal cystic lesion anteromedial to the left L4-L5 articular joint and the center of the lesion manifested gas contents. A transforaminal endoscopic procedure was performed and confirmed as a safe and minimally invasive technique for gas-containing lumbar synovial cysts. It provides a valuable substitution and supplementation to open surgery.