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Lumbar intraspinal synovial cyst containing gas as a cause for low-back pain
276
Journal of Manipulative and Physiological Therapeutics Volume 23 • Number 4 • May 2000 0161-4754/2000/$12.00 + 0 76/1/106096 © 2000 JMPT
CASE REPORTS Lumbar Intraspinal Synovial Cyst Containing Gas as a Cause for Low-Back Pain Ronnie L. Firth, DCa
ABSTRACT Objective: To discuss intraspinal synovial cysts caused by degenerative changes involving the posterior articular facets in the lumbar spine and to provide differential considerations for patients with low-back pain. Clinical Features: A 70-year-old man with low-back and gluteal pain demonstrating eventual progression of radiating pain into the left thigh, calf, ankle, and foot over a 5-month period. Radiographs of the lumbar spine revealed mild degenerative disk disease at L5-S1 with associated vacuum phenomena of the L5 disk. Degenerative osteophytes were present at L3, L4, and L5. Moderate posterior joint arthrosis was evident at L4-L5 and L5-S1. Computed tomography and magnetic resonance imaging studies revealed an intraspinal gas-containing synovial cyst at
INTRODUCTION Low-back pain is a serious public health concern, affecting 80% of the residents of the United States and the United Kingdom at some point during their lifetimes.1,2 It is the second leading reason for physician visits in ambulatory medicine.3 Low-back pain can originate from several sources, including the disk, ligaments, muscles, sacroiliac joints, and may be caused by lumbar facet joint degeneration. This case is an example of an intraspinal gas-containing synovial cyst of the facet joint, a rare complication of degenerative changes of the facet articulations. Intraspinal synovial cysts of the facet joints are uncommon entities associated with degenerative changes of the facets. It is even less common for these cysts to contain gas. Clinically, the most frequent presentation is intermittent low-back pain, radiculopathy, and symptoms of spinal stenosis. Most of these lesions occur in the lumbar spine at the L4-L5 level and to a lesser extent at the L5-S1 and L3-L4 levels. This case report describes a gas-containing intraspinal synovial cyst in the adjacent facet joint space that was demonstrated on computed tomography (CT) and magnetic resonance imaging (MRI).
CASE REPORT A 70-year-old man presented with an ache in his left buttocks and pain radiating to the left thigh, calf, ankle, and
a Professor, Department of Radiology, Palmer College of Chiropractic, Davenport, Iowa. Submit reprint requests to: Ronnie L. Firth, DC, Department of Radiology, Palmer College of Chiropractic, Davenport, Iowa 52803. Paper submitted April 19, 1999.
doi:10.1067/mmt.2000.106096
the left lateral aspect of the central canal at the level of the left L4-L5 facet articulation. Intervention and Outcome: The patient underwent surgical excision of the synovial cyst with remission of symptoms. Conclusion: Gas-containing intraspinal synovial cysts can be a significant finding and a causative factor in patients with low-back pain and pain radiating into the lower extremities. Both computed tomography and magnetic resonance imaging are important in defining intraspinal synovial cysts as a cause of back pain in patients whose low-back pain does not respond to chiropractic care. (J Manipulative Physiol Ther 2000;23:276-8) Key Indexing Terms: Computed Tomography; Magnetic Resonance Imaging; Synovial Cyst; Lumbar Spine; Articular Facets
foot. The pain was described as beginning gradually in the buttocks and eventually continuing down the lateral thigh 8 weeks later. Pain progressed into the calf, the ankle, and finally the foot a few months later. The pain was intermittent at first and was exacerbated by walking or sitting in certain positions; the pain became constant by September, approximately 5 months after initial onset of symptoms. The patient tried hanging upside down and doing leg stretches for relief in the early months; however, this offered little benefit. The pain was described as a muscle cramp-like feeling, with occasional sharpness when the patient was in certain positions. The patient reported a score of 3 to 4 initially on the visual analog scale and as high as 8 to 9 at later presentation. The pain woke the patient from sleeping; this was accompanied by increased pain in the early morning hours. The patient stated that as a result of lack of sleep, he was often disoriented, forgetful, easy to anger, and lethargic. He initially sought chiropractic care, which included radiographic examination of his lumbar spine. He underwent 15 adjustments over a period of weeks with only temporary relief. He next saw his general practitioner who prescribed pain medication, but with little benefit. The patient was then seen by a neurologist who ordered other diagnostic studies, including urinalysis, a complete blood cell count, radiographic examination of the lumbar spine, a bone scan, and CT. Finally, the patient underwent an MRI examination of the lumbar spine. The radiographic examination of the lumbar spine included anterior-posterior, lateral, and oblique projections (Fig 1), which revealed a mild reduction in disk-space height at L5S1 with associated vacuum phenomena involving the 5th lumbar disk. Degenerative vertebral osteophytes were evident at the margins of L3, L4, and L5. A moderate degree of
Journal of Manipulative and Physiological Therapeutics Volume 23 • Number 4 • May 2000 Lumbar Synovial Cyst • Firth
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Fig 1. Left, Anterior-posterior view of the lumbar spine. Middle, Lateral view of the lumbar spine. Mild posterior joint arthrosis is present at L4-L5 and L5-S1. Right, Oblique view of the lumbar spine. Mild posterior joint arthrosis is evident at L4-L5 and L5-S1.
Fig 2. Left, Axial CT (bone window) at the inferior aspect of the L4 body. Note the vacuum in the L4-L5 articular facet joint bilaterally and the hypertrophic changes of the facets. Also present is a small ovoid gas collection medial to the L4-L5 left facet articulation representing gas within a synovial cyst. Middle, Axial CT (bone window) at the L4 disk level. Note the vacuum in the facetal articulations bilaterally. An ovoid mass with a calcified rim is evident at the medial aspect of the L4-L5 facet on the left consistent with a synovial cyst. Right, Axial CT through the superior portion of the 5th lumbar disk, showing the vacuum in the disk. Osteophyte formation is also evident at the anterior margin of the inferior end plate of L5. degenerative sclerosis was seen, involving the posterior articular facets at L4-L5 and L5-S1. Calcific atherosclerotic plaguing was seen involving the abdominal aorta. CT examination of the lumbar spine (Fig 2) revealed the presence of the vacuum phenomena of the 5th lumbar disk along with degenerative osteophyte formation along the margins of L5 (Fig 2, Right). Moderate degenerative changes of the posterior articular facets at L4-L5 and L5-S1 were present, with gas within the L4-L5 facetal articulations bilaterally (Fig 2, Left and Middle). There was a small soft-tissue mass with a calcified rim and accompanying gas in the center of the mass at the left lateral aspect of the central canal at
the level of the L4-L5 facet (Fig 2, Left and Middle), representing a gas-filled synovial cyst. Ligamentum flavum hypertrophy was present at the 4th lumbar level, causing narrowing of the central spinal canal (Fig 2, Left and Middle). MRI examination of the lumbar spine was performed and included multiple sagittal and axial images. The axial images with T1 and T2 weighting are shown (Fig 3). Hypertrophic changes of the posterior articular facets were evident bilaterally at L4-L5, with thickening of the ligamentum flavum at both the 4th and 5th lumbar levels. A somewhat ovoid isointense mass with a hypointense calcific rim was present at the left lateral aspect of the central canal. This mass was next to
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Journal of Manipulative and Physiological Therapeutics Volume 23 • Number 4 • May 2000 Lumbar Synovial Cyst • Firth
articulation. Synovial cysts are thought to arise from synovial herniation through weakened or destroyed facet joint capsular tissue that continues to be in direct communication with the joint of origin.4,6-9 The chief radiographic features, although not always present, are facet joint arthropathy characterized by sclerosis and narrowing and spondylolisthesis without spondylolysis. The usual CT appearance is of a cyst density located at the posterolateral aspect of the spinal canal, adjacent to a degenerated facet articulation and often with a calcified rim. The presence of gas within the cyst density has been reported, most likely originating from the contiguous vacuum in the facet joint. This feature was observed in our case. MRI typically shows a well-circumscribed cystic mass arising adjacent to a degenerative facet joint, usually isointense to slightly hyperintense with respect to cerebrospinal fluid on T1- and T2-weighted images, with a low signal rim.6-9 Various treatment regimens, including corticosteroid injection of the cyst, direct cyst puncture with aspiration, spontaneous resolution with bed rest, surgical decompression, and cyst excision have been attempted. This patient underwent surgical removal of the cyst and has had an excellent response.
CONCLUSION
Fig 3. Top, Axial T1-weighted MRI at the level of the 4th lumbar disk. Note the round isointense mass with a hypointense rim next to the L4-L5 facet joint on the left. Bottom, Axial T2-weighted MRI at the level of the 4th lumbar disk. Note the round isointense mass with a hypointense rim (correlating with the calcified rim seen on the CT exam) adjacent to the left L4-L5 facet. the L4-L5 facetal articulation and coincided with the CT examination of a synovial cyst. The gas within the central aspect of the cyst was not appreciated on this examination. The cyst was surgically excised without complications.
DISCUSSION Synovial cysts are uncommon extradural masses that may be asymptomatic or present with low-back pain or radiculopathy. They may be caused by trauma or degenerative joint disease and occur more frequently in patients with spondylolisthesis.4-6 Most (75% to 80%) occur in the lumbar spine at the L4-L5 level, probably as a result of the greater mobility of the joint at this level. Less frequently they may be seen at the L3-L4 or L5-S1 levels.4,6-8 Lumbar synovial cysts affect both men and women and occur in the 5th and 6th decades of life. Average clinical history usually lasts several months and is often intermittent.6 Intraspinal cysts can be of 2 distinct forms: synovial and ganglionic. Synovial cysts have a synovial lining composed of pseudostratified columnar epithelium, contain a clear or xanthochromic fluid, and have a demonstrable communication to the synovial sheath or joint capsule. In contrast, the ganglion cyst does not have a synovial lining, is filled with myxoid material, and does not communicate with the facet
In summary, intraspinal synovial cysts are rare causes of back pain and radiculopathy and should be included in differential considerations, particularly when a patient’s symptoms do not respond to chiropractic care. A posterolateral location adjacent to a degenerative fact joint is typical of intraspinal synovial cysts.
ACKNOWLEDGMENTS I thank David Pflaum for his contribution of the case material.
REFERENCES 1. Deyo RA, Tsui-Wu YJ. Descriptive epidemiology of low back pain and its related medical care in the United States. Spine 1987;12:264-8. 2. Jones AK. Primary care management of acute low back pain. Nurse Pract 1997;22:50-66. 3. Deyo RA, Phillips WR. Low back pain. A primary care challenge. Spine 1996;21:2826-32. 4. Marion PJ, Kahanovitz N. Lumbar-sacral radiculopathy secondary to intraspinal synovial cysts. Arch Phys Med Rehabil 1995;76:1011-3. 5. Villas C, Leyes M. Synovial cyst in the lumbar facet joint. A rare cause of lumbar-sciatic pain [in Spanish]. Rev Med Univ Navarra 1997;41:32-5. 6. Artico M, Cervoni L, Cariola S, Stevanato G, Mastanutuono M, Nucci F. Synovial cysts: clinical and neurological aspects. Acta Neurochir (Wein) 1997;139:176-81. 7. Howling SJ, Kessel D. Case report: acute radiculopathy due to a hemorrhagic lumbar synovial cyst. Clin Radiol 1997;52:73-4. 8. Lauwers A, Courtois I, Duthel R, Alexandre C. Cauda equina syndrome due to a facet joint synovial cyst. Rev Rheum Engl Ed 1997;12:856-7. 9. Yarde WL, Arnold PM, Kepes JJ, O’Boynick PL, Wilkinson SB, Batnitsky S. Synovial cysts of the lumbar spine: diagnosis, surgical management, and pathogenesis. Surg Neurol 1995; 43:459-65.
Journal of Manipulative and Physiological Therapeutics Volume 23 • Number 4 • May 2000 0161-4754/2000/$12.00 + 0 76/1/106096 © 2000 JMPT
CASE REPORTS Lumbar Intraspinal Synovial Cyst Containing Gas as a Cause for Low-Back Pain Ronnie L. Firth, DCa
ABSTRACT Objective: To discuss intraspinal synovial cysts caused by degenerative changes involving the posterior articular facets in the lumbar spine and to provide differential considerations for patients with low-back pain. Clinical Features: A 70-year-old man with low-back and gluteal pain demonstrating eventual progression of radiating pain into the left thigh, calf, ankle, and foot over a 5-month period. Radiographs of the lumbar spine revealed mild degenerative disk disease at L5-S1 with associated vacuum phenomena of the L5 disk. Degenerative osteophytes were present at L3, L4, and L5. Moderate posterior joint arthrosis was evident at L4-L5 and L5-S1. Computed tomography and magnetic resonance imaging studies revealed an intraspinal gas-containing synovial cyst at
INTRODUCTION Low-back pain is a serious public health concern, affecting 80% of the residents of the United States and the United Kingdom at some point during their lifetimes.1,2 It is the second leading reason for physician visits in ambulatory medicine.3 Low-back pain can originate from several sources, including the disk, ligaments, muscles, sacroiliac joints, and may be caused by lumbar facet joint degeneration. This case is an example of an intraspinal gas-containing synovial cyst of the facet joint, a rare complication of degenerative changes of the facet articulations. Intraspinal synovial cysts of the facet joints are uncommon entities associated with degenerative changes of the facets. It is even less common for these cysts to contain gas. Clinically, the most frequent presentation is intermittent low-back pain, radiculopathy, and symptoms of spinal stenosis. Most of these lesions occur in the lumbar spine at the L4-L5 level and to a lesser extent at the L5-S1 and L3-L4 levels. This case report describes a gas-containing intraspinal synovial cyst in the adjacent facet joint space that was demonstrated on computed tomography (CT) and magnetic resonance imaging (MRI).
CASE REPORT A 70-year-old man presented with an ache in his left buttocks and pain radiating to the left thigh, calf, ankle, and
a Professor, Department of Radiology, Palmer College of Chiropractic, Davenport, Iowa. Submit reprint requests to: Ronnie L. Firth, DC, Department of Radiology, Palmer College of Chiropractic, Davenport, Iowa 52803. Paper submitted April 19, 1999.
doi:10.1067/mmt.2000.106096
the left lateral aspect of the central canal at the level of the left L4-L5 facet articulation. Intervention and Outcome: The patient underwent surgical excision of the synovial cyst with remission of symptoms. Conclusion: Gas-containing intraspinal synovial cysts can be a significant finding and a causative factor in patients with low-back pain and pain radiating into the lower extremities. Both computed tomography and magnetic resonance imaging are important in defining intraspinal synovial cysts as a cause of back pain in patients whose low-back pain does not respond to chiropractic care. (J Manipulative Physiol Ther 2000;23:276-8) Key Indexing Terms: Computed Tomography; Magnetic Resonance Imaging; Synovial Cyst; Lumbar Spine; Articular Facets
foot. The pain was described as beginning gradually in the buttocks and eventually continuing down the lateral thigh 8 weeks later. Pain progressed into the calf, the ankle, and finally the foot a few months later. The pain was intermittent at first and was exacerbated by walking or sitting in certain positions; the pain became constant by September, approximately 5 months after initial onset of symptoms. The patient tried hanging upside down and doing leg stretches for relief in the early months; however, this offered little benefit. The pain was described as a muscle cramp-like feeling, with occasional sharpness when the patient was in certain positions. The patient reported a score of 3 to 4 initially on the visual analog scale and as high as 8 to 9 at later presentation. The pain woke the patient from sleeping; this was accompanied by increased pain in the early morning hours. The patient stated that as a result of lack of sleep, he was often disoriented, forgetful, easy to anger, and lethargic. He initially sought chiropractic care, which included radiographic examination of his lumbar spine. He underwent 15 adjustments over a period of weeks with only temporary relief. He next saw his general practitioner who prescribed pain medication, but with little benefit. The patient was then seen by a neurologist who ordered other diagnostic studies, including urinalysis, a complete blood cell count, radiographic examination of the lumbar spine, a bone scan, and CT. Finally, the patient underwent an MRI examination of the lumbar spine. The radiographic examination of the lumbar spine included anterior-posterior, lateral, and oblique projections (Fig 1), which revealed a mild reduction in disk-space height at L5S1 with associated vacuum phenomena involving the 5th lumbar disk. Degenerative vertebral osteophytes were evident at the margins of L3, L4, and L5. A moderate degree of
Journal of Manipulative and Physiological Therapeutics Volume 23 • Number 4 • May 2000 Lumbar Synovial Cyst • Firth
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Fig 1. Left, Anterior-posterior view of the lumbar spine. Middle, Lateral view of the lumbar spine. Mild posterior joint arthrosis is present at L4-L5 and L5-S1. Right, Oblique view of the lumbar spine. Mild posterior joint arthrosis is evident at L4-L5 and L5-S1.
Fig 2. Left, Axial CT (bone window) at the inferior aspect of the L4 body. Note the vacuum in the L4-L5 articular facet joint bilaterally and the hypertrophic changes of the facets. Also present is a small ovoid gas collection medial to the L4-L5 left facet articulation representing gas within a synovial cyst. Middle, Axial CT (bone window) at the L4 disk level. Note the vacuum in the facetal articulations bilaterally. An ovoid mass with a calcified rim is evident at the medial aspect of the L4-L5 facet on the left consistent with a synovial cyst. Right, Axial CT through the superior portion of the 5th lumbar disk, showing the vacuum in the disk. Osteophyte formation is also evident at the anterior margin of the inferior end plate of L5. degenerative sclerosis was seen, involving the posterior articular facets at L4-L5 and L5-S1. Calcific atherosclerotic plaguing was seen involving the abdominal aorta. CT examination of the lumbar spine (Fig 2) revealed the presence of the vacuum phenomena of the 5th lumbar disk along with degenerative osteophyte formation along the margins of L5 (Fig 2, Right). Moderate degenerative changes of the posterior articular facets at L4-L5 and L5-S1 were present, with gas within the L4-L5 facetal articulations bilaterally (Fig 2, Left and Middle). There was a small soft-tissue mass with a calcified rim and accompanying gas in the center of the mass at the left lateral aspect of the central canal at
the level of the L4-L5 facet (Fig 2, Left and Middle), representing a gas-filled synovial cyst. Ligamentum flavum hypertrophy was present at the 4th lumbar level, causing narrowing of the central spinal canal (Fig 2, Left and Middle). MRI examination of the lumbar spine was performed and included multiple sagittal and axial images. The axial images with T1 and T2 weighting are shown (Fig 3). Hypertrophic changes of the posterior articular facets were evident bilaterally at L4-L5, with thickening of the ligamentum flavum at both the 4th and 5th lumbar levels. A somewhat ovoid isointense mass with a hypointense calcific rim was present at the left lateral aspect of the central canal. This mass was next to
278
Journal of Manipulative and Physiological Therapeutics Volume 23 • Number 4 • May 2000 Lumbar Synovial Cyst • Firth
articulation. Synovial cysts are thought to arise from synovial herniation through weakened or destroyed facet joint capsular tissue that continues to be in direct communication with the joint of origin.4,6-9 The chief radiographic features, although not always present, are facet joint arthropathy characterized by sclerosis and narrowing and spondylolisthesis without spondylolysis. The usual CT appearance is of a cyst density located at the posterolateral aspect of the spinal canal, adjacent to a degenerated facet articulation and often with a calcified rim. The presence of gas within the cyst density has been reported, most likely originating from the contiguous vacuum in the facet joint. This feature was observed in our case. MRI typically shows a well-circumscribed cystic mass arising adjacent to a degenerative facet joint, usually isointense to slightly hyperintense with respect to cerebrospinal fluid on T1- and T2-weighted images, with a low signal rim.6-9 Various treatment regimens, including corticosteroid injection of the cyst, direct cyst puncture with aspiration, spontaneous resolution with bed rest, surgical decompression, and cyst excision have been attempted. This patient underwent surgical removal of the cyst and has had an excellent response.
CONCLUSION
Fig 3. Top, Axial T1-weighted MRI at the level of the 4th lumbar disk. Note the round isointense mass with a hypointense rim next to the L4-L5 facet joint on the left. Bottom, Axial T2-weighted MRI at the level of the 4th lumbar disk. Note the round isointense mass with a hypointense rim (correlating with the calcified rim seen on the CT exam) adjacent to the left L4-L5 facet. the L4-L5 facetal articulation and coincided with the CT examination of a synovial cyst. The gas within the central aspect of the cyst was not appreciated on this examination. The cyst was surgically excised without complications.
DISCUSSION Synovial cysts are uncommon extradural masses that may be asymptomatic or present with low-back pain or radiculopathy. They may be caused by trauma or degenerative joint disease and occur more frequently in patients with spondylolisthesis.4-6 Most (75% to 80%) occur in the lumbar spine at the L4-L5 level, probably as a result of the greater mobility of the joint at this level. Less frequently they may be seen at the L3-L4 or L5-S1 levels.4,6-8 Lumbar synovial cysts affect both men and women and occur in the 5th and 6th decades of life. Average clinical history usually lasts several months and is often intermittent.6 Intraspinal cysts can be of 2 distinct forms: synovial and ganglionic. Synovial cysts have a synovial lining composed of pseudostratified columnar epithelium, contain a clear or xanthochromic fluid, and have a demonstrable communication to the synovial sheath or joint capsule. In contrast, the ganglion cyst does not have a synovial lining, is filled with myxoid material, and does not communicate with the facet
In summary, intraspinal synovial cysts are rare causes of back pain and radiculopathy and should be included in differential considerations, particularly when a patient’s symptoms do not respond to chiropractic care. A posterolateral location adjacent to a degenerative fact joint is typical of intraspinal synovial cysts.
ACKNOWLEDGMENTS I thank David Pflaum for his contribution of the case material.
REFERENCES 1. Deyo RA, Tsui-Wu YJ. Descriptive epidemiology of low back pain and its related medical care in the United States. Spine 1987;12:264-8. 2. Jones AK. Primary care management of acute low back pain. Nurse Pract 1997;22:50-66. 3. Deyo RA, Phillips WR. Low back pain. A primary care challenge. Spine 1996;21:2826-32. 4. Marion PJ, Kahanovitz N. Lumbar-sacral radiculopathy secondary to intraspinal synovial cysts. Arch Phys Med Rehabil 1995;76:1011-3. 5. Villas C, Leyes M. Synovial cyst in the lumbar facet joint. A rare cause of lumbar-sciatic pain [in Spanish]. Rev Med Univ Navarra 1997;41:32-5. 6. Artico M, Cervoni L, Cariola S, Stevanato G, Mastanutuono M, Nucci F. Synovial cysts: clinical and neurological aspects. Acta Neurochir (Wein) 1997;139:176-81. 7. Howling SJ, Kessel D. Case report: acute radiculopathy due to a hemorrhagic lumbar synovial cyst. Clin Radiol 1997;52:73-4. 8. Lauwers A, Courtois I, Duthel R, Alexandre C. Cauda equina syndrome due to a facet joint synovial cyst. Rev Rheum Engl Ed 1997;12:856-7. 9. Yarde WL, Arnold PM, Kepes JJ, O’Boynick PL, Wilkinson SB, Batnitsky S. Synovial cysts of the lumbar spine: diagnosis, surgical management, and pathogenesis. Surg Neurol 1995; 43:459-65.