- Email: [email protected]
Decompressive laminectomy without fusion for lumbar facet joint cysts
Journal of Clinical Neuroscience xxx (2018) xxx–xxx
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical study
Decompressive laminectomy without fusion for lumbar facet joint cysts Kevin C. Siu, Marcus A. Stoodley ⇑ Department of Clinical Medicine, Faculty of Medicine and Health Sciences, Neurosurgery Unit, Suite 201, Level 2, 2 Technology Place, Macquarie University, NSW 2109, Australia
a r t i c l e
i n f o
Article history: Received 3 January 2018 Accepted 24 September 2018 Available online xxxx Keywords: Lumbar synovial cyst Laminectomy Spinal instability Facet joint
a b s t r a c t Lumbar synovial facet joint cysts cause nerve root compression and radiculopathy. Excision of these cysts is often performed for patients with significant symptoms. There is uncertainty regarding the need for performing a concomitant arthrodesis to prevent spinal instability. This study was performed to assess the rate of postoperative spinal instability with patients undergoing laminectomy without fusion for treatment of lumbar facet joint cysts. Patients who had received a decompressive laminectomy for excision of lumbar spinal cyst(s) without fusion from 2000 to 2015 were reviewed. Their progress was monitored over a 15 year period (2000–2015). SF-12 health surveys were completed at each clinic appointment. Patients were also contacted via phone and mail to assess their postoperative quality of life and to determine whether any further spinal surgery was performed. Forty-six patients were studied with an average follow up of 43 months (1 month–13 years). Two patients had subsequent spinal surgery, neither of which was a fusion. The mean preoperative SF-12 scores were 28 for physical function and 44 for mental function, while the final postoperative follow up score was 33 for physical function and 50 for mental function. Lumbar spinal facet joint cyst excision can be performed by laminectomy without fusion. The rate of subsequent fusion surgery is low. Ó 2018 Elsevier Ltd. All rights reserved.
1. Introduction Facet joint cysts are benign lesions that arise adjacent to the facet joints of the vertebral column. They may be found throughout the spine, but occur in the lumbar spine with the highest frequency [6]. Cysts are assumed to be the result of degenerative changes and have been reported with increasing frequency as a result of improved neuroimaging methods [6,12,16]. However, they are still considered uncommon with detection in approximately 1% of CT and MR studies performed of the spinal column [6]. Facet joint cysts are usually asymptomatic until they progress to a size large enough to compress nerve roots [14]. Surgical excision is the preferred treatment for symptomatic lumbar synovial cyst(s) [6,16]. The approach to the excision of lumbar synovial cysts varies depending on size, location and patient anatomy – hence surgical intervention involves various combinations of hemilaminectomy, laminectomy, medial facetectomy or total facetectomy with or without arthrodesis [16]. There has been debate regarding the need for performing a concomitant arthrodesis at the time of excision of lumbar synovial ⇑ Corresponding author at: Neurosurgery Unit, Suite 201, Level 2, The Australian School of Advanced Medicine, 2 Technology Place, Macquarie University, NSW 2109, Australia. E-mail addresses: [email protected] (K.C. Siu), marcus.stoodley@mq. edu.au (M.A. Stoodley).
cysts. Some authors claim that arthrodesis is a necessary procedure as cyst excision often disrupts spinal architecture and results in future spinal instability [5–7,12]. There have also been reports that superior outcomes are achieved by performing a spinal segment fusion compared to patients who did not receive fusion [7]. However, more recent studies promote microsurgical approaches, which reduce the amount of spinal disruption and advocate against performing a concomitant spinal arthrodesis [5,9]. The current study aims to analyse patients who underwent decompressive laminectomy without arthrodesis and assess their long-term postoperative outcomes with the end point of whether or not a subsequent spinal fusion procedure was performed. It was hypothesised that a protocol of laminectomy without fusion for patients with facet joint cysts does not result in a high rate of spinal instability. 2. Materials and methods Ethics approval was obtained from the Macquarie University Human Research Ethics Committee. The patients included in the study comprised individuals over the age of 30 who had excision of a lumbar facet joint cyst confirmed intraoperatively without a spinal fusion procedure being performed between August 2000 to April 2015. Patients with facet joint cysts associated with grade 2 or higher spondylolisthesis or dynamic x-ray demonstrating
https://doi.org/10.1016/j.jocn.2018.09.013 0967-5868/Ó 2018 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013
2
K.C. Siu, M.A. Stoodley / Journal of Clinical Neuroscience xxx (2018) xxx–xxx
instability were excluded. Laminectomies were performed with a midline approach, removal of the spinous process and preservation of the facet joints by undercutting. Postoperative imaging was performed only if there were new or persisting symptoms. All patients completed the 12-Item Short Form Survey (SF-12) preoperatively and at all postoperative clinic visits. In order to obtain the most up-to-date information, patients were contacted via mail with a participant information and consent form along with an SF-12 questionnaire. Patients who responded were also contacted by phone to determine whether any further spinal procedures had been performed. Patient demographics, symptoms and signs prior to surgery, medical co-morbidities, level and side of lumbar spinal cyst, presence of stenosis and spondylolisthesis, date of operation, and preoperative SF-12 data were extracted from a prospectively collected clinical database and entered into an Excel spreadsheet (Microsoft, Redmond, WA) for data processing and analysis. Postoperative follow up data and SF-12 health survey results were also included in the spreadsheet.
3. Results Forty-six patients (17 males and 29 females) with an average age of 67 satisfied the inclusion criteria. All patients were reviewed postoperatively in clinic. Twenty-one patients (45%) responded to the mailed questionnaire and agreed to be contacted. One patient declined to participate. Follow up ranged from 1 month to 13 years (median ± SD, 37 ± 43 months). Demographic and clinical data are shown in Table 1. The most common symptoms were sciatic pain (46 patients, 100%), back pain (35 patients, 76%), and neurogenic claudication (24 patients, 52%). Facet joint cysts were most commonly found at the L4/5 level (30 patients, 65%), followed by the L5/S1 level (12 patients, 26%). No cysts were identified rostral to the L3/4 level. Canal stenosis was most prevalent at the L4/5 level (31 patients, 67%), followed by the L3/4 level (19 patients, 41%). Preoperative grade 1 spondylolisthesis was present in 18 patients (39%), most commonly at the L4/5 level (Table 1). Eight patients had spinal surgery prior to the laminectomy for facet joint cyst. Five patients had a single level laminectomy, two patients had a two level laminectomy and one patient had a microdiscectomy and foraminotomy. The most common procedure performed was a laminectomy at a single level for 32 patients. Two level procedures were performed for 11 patients. Five complications were experienced in the patient cohort. Three patients experienced persistent or recurrent radicular pain from either new or persistent canal stenosis. One of which required a subsequent repeat laminectomy at the same level. One patient was diagnosed with a pulmonary embolism in the postoperative period requiring anticoagulation and another patient experienced a small dural tear intraoperatively. New postoperative grade 1 spondylolisthesis was detected in seven patients and was most common at the L4/5 level (4 patients), followed by L5/S1 (2 patients) and L3/4 (1 patient). All of the newly developed postoperative spondylolisthesis was at the level of the excision of the lumbar facet joint cyst. Ten patients (22%) received facet joint steroid injections following surgery for treatment of back pain. Cyst recurrence or development of a cyst in a new location occurred in five patients (11%) with one patient undergoing revision laminectomy. Two patients had further spinal surgery after the original laminectomy: one had a microdiscectomy for a foraminal disc protrusion at the level of the initial facet joint cyst operation and the other had a laminectomy at the level below for persistent symptoms related to canal stenosis following the facet joint cyst excision.
Table 1 Patient demographic and clinical data. Variable
Value
Total number of patients (n) Mean age in years (range) Sex (M/F) Radicular pain Back pain Left lower limb pain Right lower limb pain Left lower limb pain > Right lower limb pain Right lower limb pain > Left lower limb pain Weakness Paraesthesia Straight leg raise positive Neurogenic claudication Rheumatoid arthritis
46 (100%) 67 (47–87) 17/29 (37%, 63%) 46 (100%) 35 (76%) 34 (74%) 21 (46%) 26 (57%) 18 (39%) 8 (17%) 22 (48%) 23 (50%) 24 (52%) 3 (7%)
Canal Stenosis L1/2 L2/3 L3/4 L4/5 L5/S1
1 (2%) 6 (13%) 19 (41%) 31 (67%) 9 (20%)
Preoperative spondylolisthesis L2/3 L3/4 L4/5 L5/S1
1 2 9 6
Lumbar synovial cysts L3/4 L4/5 L5/S1
6 (13%) 30 (65%) 12 (26%)
Left sided cysts Right sided cysts Bilateral cysts
23 (50%) 16 (35%) 7 (15%)
Number of levels operated 1 2 3 4
32 (70%) 11 (24%) 2 (4%) 1 (2%)
Cyst recurrence Mean follow-up period in months (range)
5 (11%) 43 (1–148)
(2%) (4%) (20%) (13%)
The average (±SD) preoperative SF-12 health survey physical and mental health composite scale scores were 28 ± 7 and 44 ± 11 respectively. The postoperative scores were grouped into less than 3 months, 3–6 months, 6–12 months, and over 12 months (Fig. 1). The average SF-12 health survey physical and mental health scores from last reported follow up were 34 ± 9 and 50 ± 11. The SF-12 physical and mental health difference scores showed an improvement following surgery over the follow up period (Table 2).
Fig. 1. Pre-operative and postoperative Short-form 12 scores for patients undergoing laminectomy without fusion for lumbar facet joint cysts.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013
3
K.C. Siu, M.A. Stoodley / Journal of Clinical Neuroscience xxx (2018) xxx–xxx Table 2 Average scores for preoperative SF-12 and final SF-12. Pre-operative
SF-12 (PCS) SF-12 (MCS)
28 44
Months <3
3–6
6–12
34 49
30 46
31 51
4. Discussion There has been an increased number of lumbar spinal fusion operations performed worldwide with an increase of over 200% over the past decade in the United States and an increase of 175% in Australia [2]. Lumbar synovial facet joint cysts are generally treated with a laminectomy with or without a fusion. Some authors advocate performing a fusion procedure when lumbar facet joint cysts are excised as surgical decompression and involvement of the facet joints have been suggested to disrupt spinal stability [7,12]. Fusion procedures have been associated with an increased rate of complications (up to 18%) when compared to laminectomy decompression alone [8]. These include an increased likelihood of incidental durotomies, deep venous thrombosis and wound infections. The current study indicates that there is a low rate of spinal instability following excision of lumbar facet joint cyst(s) in the absence of significant spondylolisthesis, and that a fusion procedure is generally not necessary. Lumbar synovial facet joint cysts were found to be more common in females in a 1.7:1 ratio and were often identified in patients in their sixth decade of life. The findings were consistent with studies performed by Amato [1], Mavrogenis [12] and Sabo [15] which show a slight female preponderance to development of lumbar facet joint cysts and that they tend to develop in patients around sixty years of age. There were no fusion procedures performed in the cohort studied. Two participants had spinal surgery following the excision of their lumbar spinal cyst. It is possible that some patients were lost to follow up and had spinal surgery elsewhere, or that patients with back pain and instability were not offered spinal fusion, although there was no evidence for this in the clinical records. The SF-12 data showed that patient health outcomes improved across both physical and mental health component scores from the preoperative to postoperative period. A study reviewing SF-12 scores for the general population in South Australia showed that patients tend to score lower on physical health scale, but higher on the mental health scale with increasing age [3]. Luo et al. conducted an analysis of SF-12 surveys completed in a population of patients with back pain and also demonstrated that the physical component score of the SF-12 declines with increasing age in a population with back pain [10]. The scores in the current study revealed progressively increasing mental health and physical health outcomes with the excision of facet joint cysts without fusion (Table 2). Preoperative or intraoperative detection of spondylolisthesis has been used as an indication for performing a concomitant spinal fusion [11]. However, the presence of preoperative spondylolisthesis was not always associated with spinal instability following a lumbar laminectomy for excision of a spinal cyst. In the study performed by Lyons, et al. there was only one patient who had preoperative spondylolisthesis who developed subsequent spinal instability necessitating fusion [11]. In the study performed by Metellus et al. 48% of patients who participated had preoperative spondylolisthesis and subsequent fusion was performed in one patient [13]. In the current study, eighteen patients (39%) had preoperative spondylolisthesis, which was most common at the L4/5 level. This
Final recorded
Final score – Pre-operative score
34 50
5 6
is consistent with the study performed by Banning et al. [4] who found that 12 patients (41%) had preoperative spondylolisthesis and also found that the most common level was at L4/5. In their study, two patients underwent concurrent resection and fusion and another two patients required a surgical fusion at a later stage. The rate of fusion for patients in Banning’s study is approximately 14%. However, their study did not report the grade of spondylolisthesis and it is possible that the fusion rate may be lower for patients with low grade spondylolisthesis. New postoperative spondylolisthesis was detected in seven patients in the postoperative period in this study with the spondylolisthesis developing at the level of the original cyst excision. None of these patients underwent a fusion operation. However, there may be an underreporting of the presence of postoperative spondylolisthesis arising from the lack of indication for further imaging following resolution of symptoms following cyst excision. It is possible that some patients were lost to follow up and had subsequent surgery performed elsewhere. Onofrio and Mih reviewed 12 patients with lumbar spinal cysts where 8 patients (67%) displayed evidence of spondylolisthesis at or adjacent to the index vertebral level following excision [14]. No fusion procedures were performed in their study and most of their patients had a beneficial outcome with partial or complete resolution of their primary presenting symptoms. Mavrogenis, et al. performed a study on 24 patients with lumbar synovial cysts where preoperative spondylolisthesis was not reported [12]. In their study, 10 patients were found intraoperatively to have segmental instability and spinal fusion was performed for all 24 of their patients. Excellent or good results were reported in 20 of the patients. Amato, et al. reviewed 40 patients, 10 with preoperative spondylolisthesis (25%) and one patient had a concomitant fusion at time of excision [1]. In the same study at follow up, a further 4 patients developed instability requiring fusion. The data from the studies reviewed above and the current study suggests that spinal fusion rates following excision of a lumbar spinal cyst range from 0 to 14% when the impact of the grade of spondylolisthesis is not taken into consideration. The current study suggests that the rate of developing spinal instability requiring fusion following excision of a lumbar spinal facet joint cyst is low in patients with grade 1 spondylolisthesis. Khan et al. claimed that patients who received spinal segment fusions had superior outcomes [7]. While the current study is unable to compare a non-fusion population to a fusion population, the postoperative increase in both physical and mental SF-12 scores suggests an improvement to general health following laminectomy alone. The technique by which lumbar spinal cysts are excised may play an important role in the long term stability of spinal architecture. Performing a laminectomy and cyst excision by undercutting and preserving the facet joint integrity may reduce the likelihood of instability. Five patients (11%) in the current study developed cyst recurrence with one of these patients requiring repeat surgery at a caudal level for persistent symptoms. Cyst recurrence was detected in two patients (5%) enrolled in the study performed by Amato et al. [1] The conditions surrounding recurrence of spinal cysts remain to be elucidated.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013
4
K.C. Siu, M.A. Stoodley / Journal of Clinical Neuroscience xxx (2018) xxx–xxx
5. Conclusions Treatment of symptomatic lumbar synovial cyst by laminectomy with or without the presence of grade 1 spondylolisthesis is safe and has a low rate of subsequent spinal fusion. Sources of support No conflicts of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jocn.2018.09.013. References [1] Amato V, Giannachi L, Irace C, Corona C. Lumbar synovial cysts: microsurgical treatment and outcome in 40 cases: review and critical analysis of the literature. Spine Neurosurg 2014, 2014.. [2] Atkinson L, Zacest A. Surgical management of low back pain. Med J Aust 2016;204:299–300. [3] Avery J, Dal Grande E, Taylor A. Quality of life in South Australia as measured by the SF12. Health Status Questionnaire 2004. [4] Banning CS, Thorell WE. Leibrock LG: Patient outcome after resection of lumbar juxtafacet cysts. Spine (Phila Pa 1976) 2001;26:969–72. [5] Bashir el F, Ajani O. Management of lumbar spine juxtafacet cysts. World Neurosurg 2012;77:141–6.
[6] Epstein NE. Lumbar synovial cysts: a review of diagnosis, surgical management, and outcome assessment. J Spinal Disord Tech 2004;17:321–5. [7] Khan AM, Synnot K, Cammisa FP, Girardi FP. Lumbar synovial cysts of the spine: an evaluation of surgical outcome. J Spinal Disord Tech 2005; 18:127–31. [8] Knafo S, Page P, Pallud J, Roux FX, Abi-Lahoud G. Surgical management of spinal synovial cysts: a series of 23 patients and systematic analysis of the literature. J Spinal Disord Tech 2015;28:211–7. [9] Landi A, Marotta N, Tarantino R, Ruggeri AG, Cappelletti M, Ramieri A, et al. 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. Neurosurg Rev 2012;35:245–53. discussion 253. [10] Luo X, George ML, Kakouras I, Edwards CL, Pietrobon R, Richardson W, et al. Reliability, validity, and responsiveness of the short form 12-item survey (SF12) in patients with back pain. Spine (Phila Pa 1976) 2003;28:1739–45. [11] Lyons MK, Atkinson JL, Wharen RE, Deen HG, Zimmerman RS, Lemens SM. Surgical evaluation and management of lumbar synovial cysts: the Mayo Clinic experience. J Neurosurg 2000;93:53–7. [12] Mavrogenis AF, Papagelopoulos PJ, Sapkas GS, Korres DS, Pneumaticos SG. Lumbar synovial cysts. J Surg Orthopaedic Adv 2012;21:232–6. [13] Metellus P, Fuentes S, Adetchessi T, Levrier O, Flores-Parra I, Talianu D, et al. Retrospective study of 77 patients harbouring lumbar synovial cysts: functional and neurological outcome. Acta Neurochir (Wien) 2006; 148:47–54. discussion 54. [14] Onofrio BM, Mih AD. Synovial cysts of the spine. Neurosurgery 1988; 22:642–7. [15] Sabo RA, Tracy PT, Weinger JM. A series of 60 juxtafacet cysts: clinical presentation, the role of spinal instability, and treatment. J Neurosurg 1996; 85:560–5. [16] Xu R, McGirt MJ, Parker SL, Bydon M, Olivi A, Wolinsky JP, et al. Factors associated with recurrent back pain and cyst recurrence after surgical resection of one hundred ninety-five spinal synovial cysts: analysis of one hundred sixty-seven consecutive cases. Spine (Phila Pa 1976) 2010; 35:1044–53.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical study
Decompressive laminectomy without fusion for lumbar facet joint cysts Kevin C. Siu, Marcus A. Stoodley ⇑ Department of Clinical Medicine, Faculty of Medicine and Health Sciences, Neurosurgery Unit, Suite 201, Level 2, 2 Technology Place, Macquarie University, NSW 2109, Australia
a r t i c l e
i n f o
Article history: Received 3 January 2018 Accepted 24 September 2018 Available online xxxx Keywords: Lumbar synovial cyst Laminectomy Spinal instability Facet joint
a b s t r a c t Lumbar synovial facet joint cysts cause nerve root compression and radiculopathy. Excision of these cysts is often performed for patients with significant symptoms. There is uncertainty regarding the need for performing a concomitant arthrodesis to prevent spinal instability. This study was performed to assess the rate of postoperative spinal instability with patients undergoing laminectomy without fusion for treatment of lumbar facet joint cysts. Patients who had received a decompressive laminectomy for excision of lumbar spinal cyst(s) without fusion from 2000 to 2015 were reviewed. Their progress was monitored over a 15 year period (2000–2015). SF-12 health surveys were completed at each clinic appointment. Patients were also contacted via phone and mail to assess their postoperative quality of life and to determine whether any further spinal surgery was performed. Forty-six patients were studied with an average follow up of 43 months (1 month–13 years). Two patients had subsequent spinal surgery, neither of which was a fusion. The mean preoperative SF-12 scores were 28 for physical function and 44 for mental function, while the final postoperative follow up score was 33 for physical function and 50 for mental function. Lumbar spinal facet joint cyst excision can be performed by laminectomy without fusion. The rate of subsequent fusion surgery is low. Ó 2018 Elsevier Ltd. All rights reserved.
1. Introduction Facet joint cysts are benign lesions that arise adjacent to the facet joints of the vertebral column. They may be found throughout the spine, but occur in the lumbar spine with the highest frequency [6]. Cysts are assumed to be the result of degenerative changes and have been reported with increasing frequency as a result of improved neuroimaging methods [6,12,16]. However, they are still considered uncommon with detection in approximately 1% of CT and MR studies performed of the spinal column [6]. Facet joint cysts are usually asymptomatic until they progress to a size large enough to compress nerve roots [14]. Surgical excision is the preferred treatment for symptomatic lumbar synovial cyst(s) [6,16]. The approach to the excision of lumbar synovial cysts varies depending on size, location and patient anatomy – hence surgical intervention involves various combinations of hemilaminectomy, laminectomy, medial facetectomy or total facetectomy with or without arthrodesis [16]. There has been debate regarding the need for performing a concomitant arthrodesis at the time of excision of lumbar synovial ⇑ Corresponding author at: Neurosurgery Unit, Suite 201, Level 2, The Australian School of Advanced Medicine, 2 Technology Place, Macquarie University, NSW 2109, Australia. E-mail addresses: [email protected] (K.C. Siu), marcus.stoodley@mq. edu.au (M.A. Stoodley).
cysts. Some authors claim that arthrodesis is a necessary procedure as cyst excision often disrupts spinal architecture and results in future spinal instability [5–7,12]. There have also been reports that superior outcomes are achieved by performing a spinal segment fusion compared to patients who did not receive fusion [7]. However, more recent studies promote microsurgical approaches, which reduce the amount of spinal disruption and advocate against performing a concomitant spinal arthrodesis [5,9]. The current study aims to analyse patients who underwent decompressive laminectomy without arthrodesis and assess their long-term postoperative outcomes with the end point of whether or not a subsequent spinal fusion procedure was performed. It was hypothesised that a protocol of laminectomy without fusion for patients with facet joint cysts does not result in a high rate of spinal instability. 2. Materials and methods Ethics approval was obtained from the Macquarie University Human Research Ethics Committee. The patients included in the study comprised individuals over the age of 30 who had excision of a lumbar facet joint cyst confirmed intraoperatively without a spinal fusion procedure being performed between August 2000 to April 2015. Patients with facet joint cysts associated with grade 2 or higher spondylolisthesis or dynamic x-ray demonstrating
https://doi.org/10.1016/j.jocn.2018.09.013 0967-5868/Ó 2018 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013
2
K.C. Siu, M.A. Stoodley / Journal of Clinical Neuroscience xxx (2018) xxx–xxx
instability were excluded. Laminectomies were performed with a midline approach, removal of the spinous process and preservation of the facet joints by undercutting. Postoperative imaging was performed only if there were new or persisting symptoms. All patients completed the 12-Item Short Form Survey (SF-12) preoperatively and at all postoperative clinic visits. In order to obtain the most up-to-date information, patients were contacted via mail with a participant information and consent form along with an SF-12 questionnaire. Patients who responded were also contacted by phone to determine whether any further spinal procedures had been performed. Patient demographics, symptoms and signs prior to surgery, medical co-morbidities, level and side of lumbar spinal cyst, presence of stenosis and spondylolisthesis, date of operation, and preoperative SF-12 data were extracted from a prospectively collected clinical database and entered into an Excel spreadsheet (Microsoft, Redmond, WA) for data processing and analysis. Postoperative follow up data and SF-12 health survey results were also included in the spreadsheet.
3. Results Forty-six patients (17 males and 29 females) with an average age of 67 satisfied the inclusion criteria. All patients were reviewed postoperatively in clinic. Twenty-one patients (45%) responded to the mailed questionnaire and agreed to be contacted. One patient declined to participate. Follow up ranged from 1 month to 13 years (median ± SD, 37 ± 43 months). Demographic and clinical data are shown in Table 1. The most common symptoms were sciatic pain (46 patients, 100%), back pain (35 patients, 76%), and neurogenic claudication (24 patients, 52%). Facet joint cysts were most commonly found at the L4/5 level (30 patients, 65%), followed by the L5/S1 level (12 patients, 26%). No cysts were identified rostral to the L3/4 level. Canal stenosis was most prevalent at the L4/5 level (31 patients, 67%), followed by the L3/4 level (19 patients, 41%). Preoperative grade 1 spondylolisthesis was present in 18 patients (39%), most commonly at the L4/5 level (Table 1). Eight patients had spinal surgery prior to the laminectomy for facet joint cyst. Five patients had a single level laminectomy, two patients had a two level laminectomy and one patient had a microdiscectomy and foraminotomy. The most common procedure performed was a laminectomy at a single level for 32 patients. Two level procedures were performed for 11 patients. Five complications were experienced in the patient cohort. Three patients experienced persistent or recurrent radicular pain from either new or persistent canal stenosis. One of which required a subsequent repeat laminectomy at the same level. One patient was diagnosed with a pulmonary embolism in the postoperative period requiring anticoagulation and another patient experienced a small dural tear intraoperatively. New postoperative grade 1 spondylolisthesis was detected in seven patients and was most common at the L4/5 level (4 patients), followed by L5/S1 (2 patients) and L3/4 (1 patient). All of the newly developed postoperative spondylolisthesis was at the level of the excision of the lumbar facet joint cyst. Ten patients (22%) received facet joint steroid injections following surgery for treatment of back pain. Cyst recurrence or development of a cyst in a new location occurred in five patients (11%) with one patient undergoing revision laminectomy. Two patients had further spinal surgery after the original laminectomy: one had a microdiscectomy for a foraminal disc protrusion at the level of the initial facet joint cyst operation and the other had a laminectomy at the level below for persistent symptoms related to canal stenosis following the facet joint cyst excision.
Table 1 Patient demographic and clinical data. Variable
Value
Total number of patients (n) Mean age in years (range) Sex (M/F) Radicular pain Back pain Left lower limb pain Right lower limb pain Left lower limb pain > Right lower limb pain Right lower limb pain > Left lower limb pain Weakness Paraesthesia Straight leg raise positive Neurogenic claudication Rheumatoid arthritis
46 (100%) 67 (47–87) 17/29 (37%, 63%) 46 (100%) 35 (76%) 34 (74%) 21 (46%) 26 (57%) 18 (39%) 8 (17%) 22 (48%) 23 (50%) 24 (52%) 3 (7%)
Canal Stenosis L1/2 L2/3 L3/4 L4/5 L5/S1
1 (2%) 6 (13%) 19 (41%) 31 (67%) 9 (20%)
Preoperative spondylolisthesis L2/3 L3/4 L4/5 L5/S1
1 2 9 6
Lumbar synovial cysts L3/4 L4/5 L5/S1
6 (13%) 30 (65%) 12 (26%)
Left sided cysts Right sided cysts Bilateral cysts
23 (50%) 16 (35%) 7 (15%)
Number of levels operated 1 2 3 4
32 (70%) 11 (24%) 2 (4%) 1 (2%)
Cyst recurrence Mean follow-up period in months (range)
5 (11%) 43 (1–148)
(2%) (4%) (20%) (13%)
The average (±SD) preoperative SF-12 health survey physical and mental health composite scale scores were 28 ± 7 and 44 ± 11 respectively. The postoperative scores were grouped into less than 3 months, 3–6 months, 6–12 months, and over 12 months (Fig. 1). The average SF-12 health survey physical and mental health scores from last reported follow up were 34 ± 9 and 50 ± 11. The SF-12 physical and mental health difference scores showed an improvement following surgery over the follow up period (Table 2).
Fig. 1. Pre-operative and postoperative Short-form 12 scores for patients undergoing laminectomy without fusion for lumbar facet joint cysts.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013
3
K.C. Siu, M.A. Stoodley / Journal of Clinical Neuroscience xxx (2018) xxx–xxx Table 2 Average scores for preoperative SF-12 and final SF-12. Pre-operative
SF-12 (PCS) SF-12 (MCS)
28 44
Months <3
3–6
6–12
34 49
30 46
31 51
4. Discussion There has been an increased number of lumbar spinal fusion operations performed worldwide with an increase of over 200% over the past decade in the United States and an increase of 175% in Australia [2]. Lumbar synovial facet joint cysts are generally treated with a laminectomy with or without a fusion. Some authors advocate performing a fusion procedure when lumbar facet joint cysts are excised as surgical decompression and involvement of the facet joints have been suggested to disrupt spinal stability [7,12]. Fusion procedures have been associated with an increased rate of complications (up to 18%) when compared to laminectomy decompression alone [8]. These include an increased likelihood of incidental durotomies, deep venous thrombosis and wound infections. The current study indicates that there is a low rate of spinal instability following excision of lumbar facet joint cyst(s) in the absence of significant spondylolisthesis, and that a fusion procedure is generally not necessary. Lumbar synovial facet joint cysts were found to be more common in females in a 1.7:1 ratio and were often identified in patients in their sixth decade of life. The findings were consistent with studies performed by Amato [1], Mavrogenis [12] and Sabo [15] which show a slight female preponderance to development of lumbar facet joint cysts and that they tend to develop in patients around sixty years of age. There were no fusion procedures performed in the cohort studied. Two participants had spinal surgery following the excision of their lumbar spinal cyst. It is possible that some patients were lost to follow up and had spinal surgery elsewhere, or that patients with back pain and instability were not offered spinal fusion, although there was no evidence for this in the clinical records. The SF-12 data showed that patient health outcomes improved across both physical and mental health component scores from the preoperative to postoperative period. A study reviewing SF-12 scores for the general population in South Australia showed that patients tend to score lower on physical health scale, but higher on the mental health scale with increasing age [3]. Luo et al. conducted an analysis of SF-12 surveys completed in a population of patients with back pain and also demonstrated that the physical component score of the SF-12 declines with increasing age in a population with back pain [10]. The scores in the current study revealed progressively increasing mental health and physical health outcomes with the excision of facet joint cysts without fusion (Table 2). Preoperative or intraoperative detection of spondylolisthesis has been used as an indication for performing a concomitant spinal fusion [11]. However, the presence of preoperative spondylolisthesis was not always associated with spinal instability following a lumbar laminectomy for excision of a spinal cyst. In the study performed by Lyons, et al. there was only one patient who had preoperative spondylolisthesis who developed subsequent spinal instability necessitating fusion [11]. In the study performed by Metellus et al. 48% of patients who participated had preoperative spondylolisthesis and subsequent fusion was performed in one patient [13]. In the current study, eighteen patients (39%) had preoperative spondylolisthesis, which was most common at the L4/5 level. This
Final recorded
Final score – Pre-operative score
34 50
5 6
is consistent with the study performed by Banning et al. [4] who found that 12 patients (41%) had preoperative spondylolisthesis and also found that the most common level was at L4/5. In their study, two patients underwent concurrent resection and fusion and another two patients required a surgical fusion at a later stage. The rate of fusion for patients in Banning’s study is approximately 14%. However, their study did not report the grade of spondylolisthesis and it is possible that the fusion rate may be lower for patients with low grade spondylolisthesis. New postoperative spondylolisthesis was detected in seven patients in the postoperative period in this study with the spondylolisthesis developing at the level of the original cyst excision. None of these patients underwent a fusion operation. However, there may be an underreporting of the presence of postoperative spondylolisthesis arising from the lack of indication for further imaging following resolution of symptoms following cyst excision. It is possible that some patients were lost to follow up and had subsequent surgery performed elsewhere. Onofrio and Mih reviewed 12 patients with lumbar spinal cysts where 8 patients (67%) displayed evidence of spondylolisthesis at or adjacent to the index vertebral level following excision [14]. No fusion procedures were performed in their study and most of their patients had a beneficial outcome with partial or complete resolution of their primary presenting symptoms. Mavrogenis, et al. performed a study on 24 patients with lumbar synovial cysts where preoperative spondylolisthesis was not reported [12]. In their study, 10 patients were found intraoperatively to have segmental instability and spinal fusion was performed for all 24 of their patients. Excellent or good results were reported in 20 of the patients. Amato, et al. reviewed 40 patients, 10 with preoperative spondylolisthesis (25%) and one patient had a concomitant fusion at time of excision [1]. In the same study at follow up, a further 4 patients developed instability requiring fusion. The data from the studies reviewed above and the current study suggests that spinal fusion rates following excision of a lumbar spinal cyst range from 0 to 14% when the impact of the grade of spondylolisthesis is not taken into consideration. The current study suggests that the rate of developing spinal instability requiring fusion following excision of a lumbar spinal facet joint cyst is low in patients with grade 1 spondylolisthesis. Khan et al. claimed that patients who received spinal segment fusions had superior outcomes [7]. While the current study is unable to compare a non-fusion population to a fusion population, the postoperative increase in both physical and mental SF-12 scores suggests an improvement to general health following laminectomy alone. The technique by which lumbar spinal cysts are excised may play an important role in the long term stability of spinal architecture. Performing a laminectomy and cyst excision by undercutting and preserving the facet joint integrity may reduce the likelihood of instability. Five patients (11%) in the current study developed cyst recurrence with one of these patients requiring repeat surgery at a caudal level for persistent symptoms. Cyst recurrence was detected in two patients (5%) enrolled in the study performed by Amato et al. [1] The conditions surrounding recurrence of spinal cysts remain to be elucidated.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013
4
K.C. Siu, M.A. Stoodley / Journal of Clinical Neuroscience xxx (2018) xxx–xxx
5. Conclusions Treatment of symptomatic lumbar synovial cyst by laminectomy with or without the presence of grade 1 spondylolisthesis is safe and has a low rate of subsequent spinal fusion. Sources of support No conflicts of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jocn.2018.09.013. References [1] Amato V, Giannachi L, Irace C, Corona C. Lumbar synovial cysts: microsurgical treatment and outcome in 40 cases: review and critical analysis of the literature. Spine Neurosurg 2014, 2014.. [2] Atkinson L, Zacest A. Surgical management of low back pain. Med J Aust 2016;204:299–300. [3] Avery J, Dal Grande E, Taylor A. Quality of life in South Australia as measured by the SF12. Health Status Questionnaire 2004. [4] Banning CS, Thorell WE. Leibrock LG: Patient outcome after resection of lumbar juxtafacet cysts. Spine (Phila Pa 1976) 2001;26:969–72. [5] Bashir el F, Ajani O. Management of lumbar spine juxtafacet cysts. World Neurosurg 2012;77:141–6.
[6] Epstein NE. Lumbar synovial cysts: a review of diagnosis, surgical management, and outcome assessment. J Spinal Disord Tech 2004;17:321–5. [7] Khan AM, Synnot K, Cammisa FP, Girardi FP. Lumbar synovial cysts of the spine: an evaluation of surgical outcome. J Spinal Disord Tech 2005; 18:127–31. [8] Knafo S, Page P, Pallud J, Roux FX, Abi-Lahoud G. Surgical management of spinal synovial cysts: a series of 23 patients and systematic analysis of the literature. J Spinal Disord Tech 2015;28:211–7. [9] Landi A, Marotta N, Tarantino R, Ruggeri AG, Cappelletti M, Ramieri A, et al. 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. Neurosurg Rev 2012;35:245–53. discussion 253. [10] Luo X, George ML, Kakouras I, Edwards CL, Pietrobon R, Richardson W, et al. Reliability, validity, and responsiveness of the short form 12-item survey (SF12) in patients with back pain. Spine (Phila Pa 1976) 2003;28:1739–45. [11] Lyons MK, Atkinson JL, Wharen RE, Deen HG, Zimmerman RS, Lemens SM. Surgical evaluation and management of lumbar synovial cysts: the Mayo Clinic experience. J Neurosurg 2000;93:53–7. [12] Mavrogenis AF, Papagelopoulos PJ, Sapkas GS, Korres DS, Pneumaticos SG. Lumbar synovial cysts. J Surg Orthopaedic Adv 2012;21:232–6. [13] Metellus P, Fuentes S, Adetchessi T, Levrier O, Flores-Parra I, Talianu D, et al. Retrospective study of 77 patients harbouring lumbar synovial cysts: functional and neurological outcome. Acta Neurochir (Wien) 2006; 148:47–54. discussion 54. [14] Onofrio BM, Mih AD. Synovial cysts of the spine. Neurosurgery 1988; 22:642–7. [15] Sabo RA, Tracy PT, Weinger JM. A series of 60 juxtafacet cysts: clinical presentation, the role of spinal instability, and treatment. J Neurosurg 1996; 85:560–5. [16] Xu R, McGirt MJ, Parker SL, Bydon M, Olivi A, Wolinsky JP, et al. Factors associated with recurrent back pain and cyst recurrence after surgical resection of one hundred ninety-five spinal synovial cysts: analysis of one hundred sixty-seven consecutive cases. Spine (Phila Pa 1976) 2010; 35:1044–53.
Please cite this article in press as: Siu KC, Stoodley MA. Decompressive laminectomy without fusion for lumbar facet joint cysts. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.09.013