Indian Spine Journal

CASE REPORT
Year
: 2019  |  Volume : 2  |  Issue : 2  |  Page : 190--194

An Unconventional and Novel Therapeutic Technique of Anterior Indirect Decompression in a Case of C6–C7 Synovial Cyst Associated with Radiculopathy


Bharat R Dave, Gayadhar Behera, Yash Shah, Ajay Krishnan 
 Department of Spine, Stavya Spine Hospital and Research Institute, Ahmedabad, Gujarat, India

Correspondence Address:
Dr. Bharat R Dave
Stavya Spine Hospital and Research Institute, Ahmedabad, Gujarat
India

Abstract

Synovial cysts are infrequent findings in the spine and mostly located in the lumbar area. Even rarer is the occurrence of a synovial cyst in the cervical spine. The pathology arises from the facet joint and may cause pain, radiculopathy, or myelopathy. Few cases of symptomatic subaxial synovial cysts have been reported in the literature. Surgery is indicated in the presence of severe pain and neurologic compromise and involves the decompression of the cyst and the associated neural elements. Hemilaminectomy is the surgical treatment most commonly reported in the literature. However, other procedures such as complete laminectomy, CT-guided aspiration, and anterior corpectomy have been described. On the background of available literature till date, we report an unconventional and novel therapeutic technique of anterior indirect decompression in an uncommon case of a C6-C7 synovial cyst. A 67-year-old female patient had left upper limb radicular pain along the forearm and lateral fingers for 2 months. She had severe neck pain in extension and weak triceps (4/5) with the Neck Disability Index (NDI) score of 51.11% and visual analog scale (VAS) score of 8/10. Plain x-rays were suggestive of spondylosis. T2WI of MRI scan demonstrated cystic lesion on ventral aspect of C6-C7 (L) facet suggestive of synovial cyst. Anterior cervical discectomy and fusion was done, and indirect posterior decompression of the cyst was achieved. There was a complete resolution of radiculopathy immediate postoperative period with magnetic resonance imaging (MRI) showing the evidence. Motor weakness resolved by 3 months with NDI score of 8.88% and VAS of 2/10. She was asymptomatic with no evidence of disease recurrence on MRI at 24 months.



How to cite this article:
Dave BR, Behera G, Shah Y, Krishnan A. An Unconventional and Novel Therapeutic Technique of Anterior Indirect Decompression in a Case of C6–C7 Synovial Cyst Associated with Radiculopathy.Indian Spine J 2019;2:190-194


How to cite this URL:
Dave BR, Behera G, Shah Y, Krishnan A. An Unconventional and Novel Therapeutic Technique of Anterior Indirect Decompression in a Case of C6–C7 Synovial Cyst Associated with Radiculopathy. Indian Spine J [serial online] 2019 [cited 2019 Nov 18 ];2:190-194
Available from: http://www.isjonline.com/text.asp?2019/2/2/190/263285


Full Text



 Introduction



Spinal synovial cysts are intraspinal, extradural extrusions of the synovium through a capsular defect of a degenerative or unstable facet joint.[1] Histologically, they are cystic dilatations of synovium internally lined by pseudostratified columnar cells and secrete clear fluid.[2] Symptomatic synovial cysts more often occur in lumbar spine compared to cervical.[3] The etiology is uncertain and often varied such as degenerative, traumatic, and inflammatory.[4] Usually they are known to be initiated by facet joint degeneration, erosion through the joint capsule and are generally precipitated by instability or traumatic events.[2] They are commonly reported at cervicothoracic junction (C7–T1), implying the propensity of a cervical cyst at a transitional location between the fixed and mobile spine segments.[2]

Surgery is advised when there is persistent severe pain with or without neurological deficit, aiming at cyst excision and neural decompression. Decompression (hemilaminectomy) is the most common surgical procedure performed as per the literature.[2] Here, we discuss the clinical picture, imaging findings of a very uncommon C6–C7 cervical synovial cyst with neurological deficit, and an unconventional novel therapeutic surgical approach of anterior indirect decompression of the cyst along with a brief literature review.

 Case Report



A 67-year-old female presented with neck pain and left upper limb radiating pain for 2 months with a progressive increase of symptoms over 2 weeks. The pain was worse with neck extension, relatively better with flexion. There was no history of trauma. The patient was initially treated by conservative means and physiotherapy for a short period without any relief of symptoms. On physical examination, she had radiating pain from the neck over the left scapula, shoulder, along the lateral border of the forearm and lateral fingers. Neurological examination revealed the motor weakness of left triceps (4/5), wrist flexors (4/5), sensory deficit over C6–C7 distribution, and decreased left triceps reflex. Upper motor neuron signs were absent. Visual analog scale (VAS) score for arm pain and the Neck Disability Index (NDI) scores were 8/10 and 51.11%, respectively. Plain radiograph of the cervical spine revealed features suggestive of spondylosis [Figure 1]a. Magnetic resonance imaging (MRI) scans showed a T2 hyperintense cystic lesion over the ventral aspect of left C6–C7 facet joint compressing the exiting C7 nerve root in the intervertebral foramen [Figure 2]. The left C6–C7 facet showed features of degeneration [Figure 2].{Figure 1}{Figure 2}

Considering synovial cyst to be a sign of hypermobility, fusion was considered. In our case, it was planned for staged anterior surgery and posterior surgery both, but first anterior was chosen because of familiarity and better fusion rates. The patient was operated in supine position under general anesthesia with standard Southwick–Robinson approach. After level confirmation, an anterior transverse incision was made, C6–C7 disc space was exposed, and discectomy was done. The disc space was gradually and carefully distracted 1–2 mm more to achieve indirect decompression of the facet cyst. Local bone graft from the osteophytes and posterior bony end plate was used to fill the cage. Cage was inserted in a snug fit manner in the disc space followed by anterior cervical plating [Figure 1]b. No complications were encountered during surgery. Surgical time was 45 min with 50 ml of blood loss. The postoperative period was uneventful with a reduction in the left arm pain (VAS – 3/10). Postoperative screening MRI revealed a significant reduction in cyst size [Figure 3], presumed probably due to the relocation of fluid into the distracted facets. Second posterior stage of the surgery was abandoned when we noticed postoperative complete resolution of symptoms and adequacy of decompression on MRI. The patient was discharged on the 3rd postoperative day. Motor power improved by 3 months with NDI score of 8.88% and VAS score of 2/10. Follow-up MRI at the end of 3 months showed complete disappearance of the cyst with no neural compression [Figure 4]. She was asymptomatic with no evidence of disease recurrence and no implant-related complications at the end of 24-month follow-up [Figure 5].{Figure 3}{Figure 4}{Figure 5}

 Discussion



The occurrence of spinal synovial cysts is rare in the cervical spine, unlike the lumbar spine. The most common location reported in the literature is at the cervicothoracic junction (C7–T1). Lyons et al. reported 17 cases of C7–T1 cysts in their series of 35 cases.[2] A meta-analysis by Bydon et al. also stated C7–T1 to be the most common location (42 out of 101 cases).[5] There are only nine cases of symptomatic synovial cysts at C6–C7 described till now. Uschold et al. reported three cases of C6–C7 synovial cysts in their series of 12 cases.[6] Usually they are known to be initiated by facet joint degeneration, erosion through the joint capsule and are generally precipitated by instability or traumatic events.[2] Synovial cyst in the present case was located in relation to the left C6–C7 facet joint. Most probably, cervical spondylosis along with facet joint degeneration triggered the development of cyst, though there were no signs of instability or inflammatory arthritis.

Cervical spinal cysts may be clinically asymptomatic or may present with radiculopathy, myelopathy, or radiculomyelopathy with variable severity depending on their location, size, and their relationship to adjacent neural structures.[2],[7],[8] Unilateral lesions usually present with same side radiculopathy, though large cysts can cause bilateral symptoms.[9] Bydon et al. in the largest ever meta-analysis of previous 53 publications and 101 patients (including their series of 17 cases) reported that the most common presenting symptoms were radiculopathy (88.2%) and motor deficit (70.5%) in their own series of 17 patients and motor deficit (84.2%) and sensory deficit (61.4%) in the meta-analysis group.[5] Uschold et al. in their single-institution case series of 12 cases of subaxial cervical juxtafacet cysts reported neck pain and myeloradiculopathy to be most common presenting complaints.[6] Similarly, Lyons et al. in their series of 35 surgically treated subaxial cervical cysts also documented radiculopathy (22 cases) as most common presenting complaint followed by myelopathy (13 cases).[2] As per the meta-analysis by Bydon et al., the mean age at presentation ranged from 55.3 to 75.4 years, and 55.4% of patients were male. The demography and symptomatology of our patient also match the above-published literature who was a 67-year-old female with neck pain and predominant radiculopathy with a motor deficit.

Plain radiographs of the cervical spine in a patient of cervical synovial cyst show variable grades of spondylosis with or without instability. The most sensitive and specific method of detecting cervical synovial cysts is MRI. It clearly depicts the exact location, size, extent, and involvement of adjacent neural structures. MRI also helps in the planning of surgical approach. A synovial cyst is iso- to hypointense on T1 images and hyperintense on T2 images with peripheral enhancement on contrast administration.[10],[11] MRI of the present case showed T2 hyperintense and T1 hypointense lesions located on the ventral aspect of C6–C7 left facet with compression over exiting C7 nerve root. Differentials considered were a metastatic disease, meningioma, schwannoma, cystic neurofibroma, dermoid cyst, parasitary cyst, perineural cyst, extradural arachnoid cyst, hypertrophic synovitis, and hypertrophic pigmented villonodular synovitis. There are no strict guidelines in therapeutic management because of the rarity of cervical synovial cysts and lack of general consensus. However, the common agreement and standard treatment have been surgical excision along with adequate decompression, especially in patients with neurological symptoms.[11],[12] Management of patients with cervical synovial cysts is based on clinical presentation. Asymptomatic lesions can be addressed with conservative treatment and close follow-up since spontaneous regression of the cyst with the removal of mechanical stresses has been well documented.[11],[13] Steroid injection into spinal synovial cyst is debatable, and many surgeons believe that it is associated with high failure rates.[11] Percutaneous cyst aspiration though less invasive provides only temporary improvement and is associated with risk of neurologic complications. Hence, its use is limited to patients with cervical spinal cyst with associated comorbidities who may not be surgically fit.[3] Many surgical options are described for patients with spinal synovial cysts. Decompression of the spinal cord and the affected root increases the chances of speedier neurological recovery, and excellent results at follow-up have been reported.[3],[12] At present, minimally invasive as well as open decompression techniques with or without instrumented fusion are possible options. Decompression can be obtained by hemilaminectomy, complete laminectomy, or laminoplasty. In the case of instability, a supplementary instrumented fusion is recommended.[2] Furthermore, many reports recommend mandatory excision of the synovium in the facet joint to prevent recurrence.[2],[3]

The present case of C6–C7 synovial cyst with left radiculopathy was managed with a novel technique of indirect decompression through anterior approach without addressing the cyst, unlike various earlier reported cases[14],[15],[16],[17],[18] [Table 1]. The logical principle considered here was the proposed pathophysiology for the development of spinal facet cyst that is relative instability of degenerative spine near the junctional area. Hence, addressing the instability helped managing the cyst to regress and the symptoms to disappear. We could achieve this in a safer way of anterior approach and fusion of the C6–C7 segment with minimum blood loss, less postoperative discomfort, and faster recovery without any complications. The mild gentle distraction of the segment during fusion resulted in the redistribution of the cyst fluid alleviating the radiculopathy symptoms in the immediate postoperative period. Complete disappearance of the cyst was seen at 3 months with no neural compression on MRI. The patient was asymptomatic with no evidence of disease recurrence and no implant-related complications at 24 months of follow-up. However, larger series may be needed to prove its regular applicability or superiority on posterior approaches in such conditions. Nevertheless, many surgical techniques are available; the ideal surgical option remains a matter of debate; and the outcome varies depending on the cyst location, size, its adherence to the dura, concomitant spine segment pathology, and the type of decompression planned.[10],[11],[13]{Table 1}

 Conclusion



Subaxial cervical synovial cysts are very uncommon. The indirect decompression with anterior cervical discectomy and fusion has given good result in the case reported; however, the patient and the surgeon need to understand the requirement of direct decompression in case of no relief in symptoms and chances of recurrence as cyst excision is not done. We believe that an anterior approach provides indirect decompression with interbody fusion, is a novel technique of management and can be considered in similar type of pathologies.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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