The role of spinal fusion in the treatment of cervical synovial cysts: a series of 17 cases and meta-analysis

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>This study was undertaken to compare surgical outcomes between patients with atlantoaxial versus subaxial cervical synovial cysts (CSCs) and to compare outcomes between patients who underwent decompression alone versus decompression and fusion for the treatment of CSCs.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors present a series of 17 cases involving patients treated at their institution and report the surgical outcomes. Due to the rarity of CSCs, a meta-analysis was conducted, and results of the literature search were combined with the case series to enhance the power of the study.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Seventeen patients underwent surgical treatment for CSCs at our institution: 3 patients (17.6%) had atlantoaxial cysts and 14 (82.3%) had subaxial cysts. Of the 17 patients, 16 underwent a decompression and fusion; most patients experienced symptom resolution at last follow-up, and there were no cyst recurrences. A total of 54 articles (including the current series) and 101 patients were included in the meta-analysis. The mean age at presentation was 64 ± 13.9 years, and the most common symptoms were motor and sensory deficits. Forty-one patients (40.6%) presented with atlantoaxial cysts, and 60 (59.4%) with subaxial cysts. There were no significant differences between groups in terms of presenting symptoms, Nurick scores, surgical treatment, or surgical outcomes. Fifty-two patients (51.4%) underwent surgical decompression without fusion, while 49 patients (48.6%) underwent fusion. The preoperative Nurick scores were significantly lower in the fused group (p = 0.001), with an average score of 1.32 compared with 2.75 in the nonfused group. After a mean follow-up of 16.5 months, a difference of means analysis between final and preoperative Nurick scores revealed that patients who received a decompression alone improved on average 1.66 points (95% CI 1.03–2.29) compared with 0.8 points (95% CI 0.23–1.39) in the fused group (p = 0.004). However, there was no statistically significant difference in symptom resolution between the groups, and the rate of cyst recurrence was found to be 0%.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>In this study, patients with CSCs had similar outcomes regardless of cyst location and regardless of whether they underwent decompression only or fusion. In the authors' institutional experience, 16 of 17 patients underwent fusion due to underlying spinal instability. While there were no reports of cyst recurrence in their series or in the literature in patients who only received decompression, this is likely due to the limited follow-up time available for the study population. Longer follow-up and prospective and biomechanical studies are needed to corroborate these findings.</jats:p></jats:sec>

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

“…81 Furthermore, fusion without cyst evacuation was proven to be effective in cases of cysts arising from the C1/2 joint, 76 which is clearly an exceptional location. However, symptom relief, long-term outcome, and the rate of cyst recurrence with or without fusion are not different in the literature, 14,42,99 despite an increase of mechanical back pain in the nonfusion group reported by Xu et al 100 Information concerning fusion was reported for 1668 patients in the literature, and fusion was performed in 15% during the cyst resection procedure (Supplemental Table 1). The recurrence rate in studies and reports in which 50% or more of the observed cases were initially treated with fusion was nearly equal to that in studies or reports in which less than 50% or no case was fused (2.5% vs 2.2%, p = 0.8).…”

A rare cause of root-compression: Subaxial cervical synovial cyst in association with congenital fusion

“…Spondylolisthesis of C7–T1 is also a sign of advanced degeneration as seen on our patient. To our knowledge, this is the tenth reported cervical synovial cyst in conjunction with congenital fusion [2] , [11] .…”

“…Most commonly, as all types of intraspinal, extradural cysts, [4] subaxial cervical synovial cysts are located at the level C7–T1 [1] , [2] , [3] , [11] . They appear most infrequently on level C2–C3 and C5–C6 [2] , [3] .…”

“…A number of case reports and case series have accurately described the morphology of synovial cyst in the subaxial cervical area [11] . Connections to other processes like degenerative changes, rheumatoid arthritis, congenital factors and trauma have been drawn [2] .…”

“…Connections to other processes like degenerative changes, rheumatoid arthritis, congenital factors and trauma have been drawn [2] . Coherent theories have been established about their pathogenesis of synovial cysts [11] . However, at the end of the day their aetiology remains unclear [3] , [12] .…”