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Resolution of an Intraspinal Cyst Associated With Spondylolysis Causing Radiculopathy in an Adolescent Athlete: A Case Report
Case Presentation
Resolution of an Intraspinal Cyst Associated With Spondylolysis Causing Radiculopathy in an Adolescent Athlete: A Case Report Jason M. Friedrich, MD, Christopher J. Standaert, MD INTRODUCTION Although degenerative zygapophysial joint synovial cysts are well documented as a potential cause of lumbosacral radiculopathy, only 4 cases of intraspinal cysts from spondylolysis are previously reported [1-3]. Cyst formation is thought to result from chronic hypermobility of the pars defect creating a pseudoarthosis that uses synovial fluid from adjacent zygapophysial joints as demonstrated in radiologic, surgical, and postmortem anatomical studies [1]. To our knowledge, this is the first reported case of a cyst associated with spondylolysis in an adolescent and is the first to describe subacute clinical and radiologic resolution of the cyst with nonsurgical care.
CASE PRESENTATION A 17-year-old male high-school football player presented to an outpatient sports and spine clinic with a 6-week history of low back pain (LBP) that radiated to the right posterior thigh and lateral calf, and a sense of decreased power in the right lower limb with running and jumping. His symptoms required him to stop playing football. Results of a physical examination at presentation revealed an antalgic gait, difficulty heel-walking on the right, and mild weakness of right ankle dorsiflexion and eversion, great-toe extension, and hip internal rotation. Straight leg raise was positive on the right. Magnetic resonance imaging (MRI) showed a cyst adjacent to the right L5 pedicle compressing the L5 root (Figure 1A). Computed tomography revealed chronic bilateral L5 pars defects with normal zygapophysial joints (Figure 2A and B). Electrodiagnostic studies, including nerve conduction studies of the right tibial, fibular and sural nerves, bilateral H-reflexes and needle electromyography of 6 right lower limb muscles and the lumbar paraspinals demonstrated an abnormally increased proportion of polyphasic motor units in the right extensor hallicus longus but were otherwise normal. Nonsurgical treatment options discussed with the patient included rest, oral medications, and an epidural steroid injection with attempted cyst aspiration under fluoroscopy. An orthopedic spine surgical consultation was obtained regarding possible surgical options, which included cyst removal and L5-S1 fusion versus direct pars repair. The patient elected to proceed with an injection in hopes of avoiding surgery. Before the actual epidural injection, an attempt was made to aspirate the cyst via the pars defect. The fluoroscope was aligned parallel to the pars defect, and the spinal needle was directed toward the center of the defect. Final needle placement in the pars defect was confirmed with multiplanar fluoroscopy, and aspiration yielded 0.2 mL of serosanguineous fluid. This procedure was immediately followed by a right L5-S1 transforaminal epidural steroid injection under fluoroscopy for his acute right L5 radicular pain. At follow-up 3 weeks after these procedures, his leg pain had resolved. Results of his physical examination revealed a normal gait, full strength, and negative dural tension signs, and he was cleared to begin low-impact aerobic exercises. At 9 weeks, he remained without leg pain and his LBP had resolved. Given concerns regarding the potential for ongoing nerve root compromise from the cyst despite good clinical progress, a follow-up MRI was ordered and demonstrated resolution of the cyst, with no nerve compression (Figure 1B). A physical PM&R 1934-1482/10/$36.00 Printed in U.S.A.
J.M.F. Department of Rehabilitation Medicine, Box 356490, BB-928 Health Sciences Bldg, University of Washington, Seattle, WA 98195-6490.Address correspondence to: J.M.F.; e-mail: [email protected] Disclosure: nothing to disclose C.J.S. Department of Rehabilitation Medicine, University of Washington Sports and Spine Physicians, University of Washington, Seattle, WA Disclosure: 2A, Washington State Technology Clinical Committee Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org This case was presented at the AAPMR conference in Austin, TX, 2009. Submitted for publication February 18, 2010; accepted May 18, 2010.
© 2010 by the American Academy of Physical Medicine and Rehabilitation Vol. 2, 1059-1062, November 2010 DOI: 10.1016/j.pmrj.2010.05.010
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INTRASPINAL CYST AND SPONDYLOLYSIS CAUSING RADICULOPATHY
Figure 1. (A) Initial MRI shows cyst adjacent to the right L5 pedicle. (B) Follow-up MRI at 9 weeks after treatment shows resolution of the cyst.
therapy program that focused on functional stability was initiated in preparation for his upcoming baseball season. In hopes of decreasing his risk of recurrent cyst formation, we supported his decision to avoid future participation in football and also recommended against exercises that involved high loads on the spine, such as squats and power-cleans, indefinitely.
DISCUSSION Intraspinal synovial cysts are typically associated with degenerative zygapophysial joints. They occur most commonly in patients older than 60 years, at the L4-5 level [4]. Although sometimes asymptomatic, zygapophysial cysts are a welldocumented cause of lumbar radiculopathy, likely through
Figure 2. (A) CT scan shows chronic bilateral L5 pars defects. (B) CT scan shows normal L5-S1 zygapophysial joints.
PM&R
mechanical compression of the exiting nerve root in the lateral recess and associated chemoinflammatory response [1,4]. In contrast to zygapophysial cysts, synovial cysts related to chronic defects in the pars interarticularis have only rarely been identified as a cause of lumbar radiculopathy. Isthmic spondylolysis, defined as a defect in the pars interarticularis, is found in about 5% of the population by age 6 years, generally identified as an asymptomatic radiographic finding [5]. In adolescent athletes, however, spondylolysis occurs at higher rates and represents the most common identifiable cause of activity-limiting LBP [5]. In the absence of a significant spondylolisthesis and resultant foraminal stenosis, isolated pars defects are rarely associated with radicular pain. Although many pars defects identified in young athletes do not develop bony union, the overwhelming majority of affected athletes do well clinically and return to play. True bony healing is more likely to occur with unilateral defects and in lesions with earlier appearing radiologic characteristics [5]. Although rare, a synovial cyst can develop as a complication of a chronic pars defect. There are only 4 previously reported cases that document symptomatic intraspinal cysts related to chronic spondylolysis [1-3]. All 4 cases were adults (ages 23-39 years), all presented with LBP and radicular symptoms, and all were confirmed intraoperatively to have a cyst associated with the pars defect. Results of a histologic examination revealed a synovial cyst in 3 cases and was not reported in the other case. Similar to our case, the pars defect was present at the L5 level in 3 of the cases, whereas the other case was at L3 in a patient with a history of lower back trauma. Contrary to these reports, our case documents occurrence in an adolescent (age 17 years) and, to our knowledge, is the first to report subacute clinical and radiologic resolution without surgery.
Pathophysiology and Anatomic Correlates DePalma et al [1] previously reviewed the pathophysiology of intraspinal cyst formation related to spondylolysis. It is thought that the introduction of synovial fluid into the pars defect from adjacent zygapophysial joints may contribute to inadequate bony healing and pseudoarthrosis formation. With continued motion and loading, degeneration occurs at the pseudoarthrosis. Similar to a zygapophysial cyst, synovial tissue can herniate through the incompetent fibrous capsule of the pseudoarthrosis and form a synovial cyst. The cyst can then cause both mechanical and chemical effects on adjacent nerve roots and produce radicular symptoms. Results of histologic studies confirmed the synovial nature of pseudoarthroses that form at chronic pars defects [1]. Surgical, postmortem, and radiologic studies also demonstrated continuity between pars defects and adjacent zyg-
Vol. 2, Iss. 11, 2010
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apophysial joints [1]. In 1981, Maldague et al [6] performed single zygapophysial joint arthrography on 11 patients with and on 51 patients without spondylolysis, and found that 9 of the 11 patients with spondylolysis showed contrast flowing into both the joint directly injected and the joint on the other side of the pars defect. There was no continuity between zygapophysial joints demonstrated in patients without spondylolysis. It has been proposed that the presence of synovial fluid in the pars defect may prevent bony healing and may contribute to the relatively low healing rate of pars fractures compared with other stress fractures throughout the body [1]. Other biomechanical factors likely also contribute.
Treatment There are few published articles available to guide the treatment of a synovial cyst associated with a chronic pars defect. The natural history of synovial cysts related to either degenerative lumbar zygapophysial joints or chronic spondylolysis is not well documented. Spontaneous resolution of degenerative zygapophysial cysts has been documented [7], but the frequency with which this may occur is unclear. Although their pathophysiology differs, some treatment options for cysts related to spondylolysis may be inferred from the limited information available for zygapophysial cysts. Retrospective studies indicate high success rates (up to 91%) for improvement of pain after surgical excision of zygapophysial cysts, although there are no randomized controlled studies that compare surgery with nonsurgical management [8]. The evidence on percutaneous treatment is limited to small retrospective series. Results of these studies indicate that various combinations of fluoroscopically guided transforaminal epidural steroid injection, zygapophysial joint injection, and attempted cyst aspiration or rupture may be associated with pain relief in up to 70% of patients observed for up to 2 years after treatment [9,10]. In our case, we used the transforaminal epidural steroid injection to improve the chemoinflammatory component of acute L5 radicular pain and attempted to aspirate the cyst in hopes of possibly reducing mechanical compression. Radiologic resolution has previously been reported after percutaneous treatments for zygapophysial cysts, with up to 50% reported to avoid surgery [10]. Research is lacking for more conservative treatment options, such as rest, physical therapy, or bracing. The few prior reports on cysts related to spondylolysis have not discussed treatment outcomes. Our case demonstrates one instance of subacute resolution of a cyst without surgical care. It remains unknown how each aspect of our treatment, including rest, cyst aspiration, and transforaminal epidural steroid injection, contributed to the clinical and radiologic resolution of the cyst.
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INTRASPINAL CYST AND SPONDYLOLYSIS CAUSING RADICULOPATHY
CONCLUSION A synovial cyst related to chronic spondylolysis is a rare cause of lumbar radiculopathy. There is limited information available on the pathogenesis, natural history, and most appropriate treatment for these cysts. It is also uncertain how much can be inferred from the available literature on synovial cysts associated with degenerative lumbar zygapophysial joints, because spondylolysis-related cysts may be a distinctly different problem, particularly when appearing in a young patient. This case demonstrates that subacute clinical and radiologic resolution of such a cyst is possible without surgical intervention in an adolescent patient with sensorimotor radiculopathy.
REFERENCES 1. DePalma MJ, Strakowski JA, Mandelker EM, et al. An instance of an atypical intraspinal cyst presenting as S1 radiculopathy: A case report and brief review of pathophysiology. Arch Phys Med Rehabil 2004;85: 1021-1025.
2. Awwad EE, Sundaram M, Bucholz RD. Post-traumatic spinal synovial cyst with spondylolysis: CT features. J Comput Assist Tomogr 1989;13: 334-337. 3. Duprez T, Mailleux P, Bodart A, et al. Retrodural cysts bridging a bilateral lumbar spondylolysis: A report of two symptomatic cases. J Comput Assist Tomogr 1999;23:534-537. 4. Khan AM, Girardi F. Spinal lumbar synovial cysts. Diagnosis and management challenge. Eur Spine J 2006;15:1176-1182. 5. Standaert CJ, Herring SA, Halpern B, et al. Spondylolysis. Phys Med Rehab Clin N Am 2000;11:785-803. 6. Maldague B, Mathurin P, Maghem J. Facet joint arthrography in lumbar spondylolysis. Radiology 1981;140:29-36. 7. Houten JK, Sanderson SP, Cooper PR. Spontaneous regression of symptomatic lumbar synovial cyst. Report of three cases. J Neurosurg Spine 2003;99:235-238. 8. Lyons MK, Atkinson JL, Wharen RE, et al. Surgical evaluation and management of lumbar synovial cysts: The Mayo Clinic experience. J Neurosurg Spine 2000;93:53-57. 9. Allen TL, Tatli Y, Lutz GE. Fluoroscopic percutaneous lumbar zygapophysial joint cyst rupture: A clinic outcome study. Spine J 2009;9: 387-395. 10. Sabers SR, Ross SR, Grogg BE, et al. Procedure-based nonsurgical management of lumbar zygapophysial joint cyst-induced radicular pain. Arch Phys Med Rehabil 2005;86:1767-1771.
Resolution of an Intraspinal Cyst Associated With Spondylolysis Causing Radiculopathy in an Adolescent Athlete: A Case Report Jason M. Friedrich, MD, Christopher J. Standaert, MD INTRODUCTION Although degenerative zygapophysial joint synovial cysts are well documented as a potential cause of lumbosacral radiculopathy, only 4 cases of intraspinal cysts from spondylolysis are previously reported [1-3]. Cyst formation is thought to result from chronic hypermobility of the pars defect creating a pseudoarthosis that uses synovial fluid from adjacent zygapophysial joints as demonstrated in radiologic, surgical, and postmortem anatomical studies [1]. To our knowledge, this is the first reported case of a cyst associated with spondylolysis in an adolescent and is the first to describe subacute clinical and radiologic resolution of the cyst with nonsurgical care.
CASE PRESENTATION A 17-year-old male high-school football player presented to an outpatient sports and spine clinic with a 6-week history of low back pain (LBP) that radiated to the right posterior thigh and lateral calf, and a sense of decreased power in the right lower limb with running and jumping. His symptoms required him to stop playing football. Results of a physical examination at presentation revealed an antalgic gait, difficulty heel-walking on the right, and mild weakness of right ankle dorsiflexion and eversion, great-toe extension, and hip internal rotation. Straight leg raise was positive on the right. Magnetic resonance imaging (MRI) showed a cyst adjacent to the right L5 pedicle compressing the L5 root (Figure 1A). Computed tomography revealed chronic bilateral L5 pars defects with normal zygapophysial joints (Figure 2A and B). Electrodiagnostic studies, including nerve conduction studies of the right tibial, fibular and sural nerves, bilateral H-reflexes and needle electromyography of 6 right lower limb muscles and the lumbar paraspinals demonstrated an abnormally increased proportion of polyphasic motor units in the right extensor hallicus longus but were otherwise normal. Nonsurgical treatment options discussed with the patient included rest, oral medications, and an epidural steroid injection with attempted cyst aspiration under fluoroscopy. An orthopedic spine surgical consultation was obtained regarding possible surgical options, which included cyst removal and L5-S1 fusion versus direct pars repair. The patient elected to proceed with an injection in hopes of avoiding surgery. Before the actual epidural injection, an attempt was made to aspirate the cyst via the pars defect. The fluoroscope was aligned parallel to the pars defect, and the spinal needle was directed toward the center of the defect. Final needle placement in the pars defect was confirmed with multiplanar fluoroscopy, and aspiration yielded 0.2 mL of serosanguineous fluid. This procedure was immediately followed by a right L5-S1 transforaminal epidural steroid injection under fluoroscopy for his acute right L5 radicular pain. At follow-up 3 weeks after these procedures, his leg pain had resolved. Results of his physical examination revealed a normal gait, full strength, and negative dural tension signs, and he was cleared to begin low-impact aerobic exercises. At 9 weeks, he remained without leg pain and his LBP had resolved. Given concerns regarding the potential for ongoing nerve root compromise from the cyst despite good clinical progress, a follow-up MRI was ordered and demonstrated resolution of the cyst, with no nerve compression (Figure 1B). A physical PM&R 1934-1482/10/$36.00 Printed in U.S.A.
J.M.F. Department of Rehabilitation Medicine, Box 356490, BB-928 Health Sciences Bldg, University of Washington, Seattle, WA 98195-6490.Address correspondence to: J.M.F.; e-mail: [email protected] Disclosure: nothing to disclose C.J.S. Department of Rehabilitation Medicine, University of Washington Sports and Spine Physicians, University of Washington, Seattle, WA Disclosure: 2A, Washington State Technology Clinical Committee Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org This case was presented at the AAPMR conference in Austin, TX, 2009. Submitted for publication February 18, 2010; accepted May 18, 2010.
© 2010 by the American Academy of Physical Medicine and Rehabilitation Vol. 2, 1059-1062, November 2010 DOI: 10.1016/j.pmrj.2010.05.010
1059
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Friedrich and Standaert
INTRASPINAL CYST AND SPONDYLOLYSIS CAUSING RADICULOPATHY
Figure 1. (A) Initial MRI shows cyst adjacent to the right L5 pedicle. (B) Follow-up MRI at 9 weeks after treatment shows resolution of the cyst.
therapy program that focused on functional stability was initiated in preparation for his upcoming baseball season. In hopes of decreasing his risk of recurrent cyst formation, we supported his decision to avoid future participation in football and also recommended against exercises that involved high loads on the spine, such as squats and power-cleans, indefinitely.
DISCUSSION Intraspinal synovial cysts are typically associated with degenerative zygapophysial joints. They occur most commonly in patients older than 60 years, at the L4-5 level [4]. Although sometimes asymptomatic, zygapophysial cysts are a welldocumented cause of lumbar radiculopathy, likely through
Figure 2. (A) CT scan shows chronic bilateral L5 pars defects. (B) CT scan shows normal L5-S1 zygapophysial joints.
PM&R
mechanical compression of the exiting nerve root in the lateral recess and associated chemoinflammatory response [1,4]. In contrast to zygapophysial cysts, synovial cysts related to chronic defects in the pars interarticularis have only rarely been identified as a cause of lumbar radiculopathy. Isthmic spondylolysis, defined as a defect in the pars interarticularis, is found in about 5% of the population by age 6 years, generally identified as an asymptomatic radiographic finding [5]. In adolescent athletes, however, spondylolysis occurs at higher rates and represents the most common identifiable cause of activity-limiting LBP [5]. In the absence of a significant spondylolisthesis and resultant foraminal stenosis, isolated pars defects are rarely associated with radicular pain. Although many pars defects identified in young athletes do not develop bony union, the overwhelming majority of affected athletes do well clinically and return to play. True bony healing is more likely to occur with unilateral defects and in lesions with earlier appearing radiologic characteristics [5]. Although rare, a synovial cyst can develop as a complication of a chronic pars defect. There are only 4 previously reported cases that document symptomatic intraspinal cysts related to chronic spondylolysis [1-3]. All 4 cases were adults (ages 23-39 years), all presented with LBP and radicular symptoms, and all were confirmed intraoperatively to have a cyst associated with the pars defect. Results of a histologic examination revealed a synovial cyst in 3 cases and was not reported in the other case. Similar to our case, the pars defect was present at the L5 level in 3 of the cases, whereas the other case was at L3 in a patient with a history of lower back trauma. Contrary to these reports, our case documents occurrence in an adolescent (age 17 years) and, to our knowledge, is the first to report subacute clinical and radiologic resolution without surgery.
Pathophysiology and Anatomic Correlates DePalma et al [1] previously reviewed the pathophysiology of intraspinal cyst formation related to spondylolysis. It is thought that the introduction of synovial fluid into the pars defect from adjacent zygapophysial joints may contribute to inadequate bony healing and pseudoarthrosis formation. With continued motion and loading, degeneration occurs at the pseudoarthrosis. Similar to a zygapophysial cyst, synovial tissue can herniate through the incompetent fibrous capsule of the pseudoarthrosis and form a synovial cyst. The cyst can then cause both mechanical and chemical effects on adjacent nerve roots and produce radicular symptoms. Results of histologic studies confirmed the synovial nature of pseudoarthroses that form at chronic pars defects [1]. Surgical, postmortem, and radiologic studies also demonstrated continuity between pars defects and adjacent zyg-
Vol. 2, Iss. 11, 2010
1061
apophysial joints [1]. In 1981, Maldague et al [6] performed single zygapophysial joint arthrography on 11 patients with and on 51 patients without spondylolysis, and found that 9 of the 11 patients with spondylolysis showed contrast flowing into both the joint directly injected and the joint on the other side of the pars defect. There was no continuity between zygapophysial joints demonstrated in patients without spondylolysis. It has been proposed that the presence of synovial fluid in the pars defect may prevent bony healing and may contribute to the relatively low healing rate of pars fractures compared with other stress fractures throughout the body [1]. Other biomechanical factors likely also contribute.
Treatment There are few published articles available to guide the treatment of a synovial cyst associated with a chronic pars defect. The natural history of synovial cysts related to either degenerative lumbar zygapophysial joints or chronic spondylolysis is not well documented. Spontaneous resolution of degenerative zygapophysial cysts has been documented [7], but the frequency with which this may occur is unclear. Although their pathophysiology differs, some treatment options for cysts related to spondylolysis may be inferred from the limited information available for zygapophysial cysts. Retrospective studies indicate high success rates (up to 91%) for improvement of pain after surgical excision of zygapophysial cysts, although there are no randomized controlled studies that compare surgery with nonsurgical management [8]. The evidence on percutaneous treatment is limited to small retrospective series. Results of these studies indicate that various combinations of fluoroscopically guided transforaminal epidural steroid injection, zygapophysial joint injection, and attempted cyst aspiration or rupture may be associated with pain relief in up to 70% of patients observed for up to 2 years after treatment [9,10]. In our case, we used the transforaminal epidural steroid injection to improve the chemoinflammatory component of acute L5 radicular pain and attempted to aspirate the cyst in hopes of possibly reducing mechanical compression. Radiologic resolution has previously been reported after percutaneous treatments for zygapophysial cysts, with up to 50% reported to avoid surgery [10]. Research is lacking for more conservative treatment options, such as rest, physical therapy, or bracing. The few prior reports on cysts related to spondylolysis have not discussed treatment outcomes. Our case demonstrates one instance of subacute resolution of a cyst without surgical care. It remains unknown how each aspect of our treatment, including rest, cyst aspiration, and transforaminal epidural steroid injection, contributed to the clinical and radiologic resolution of the cyst.
1062
Friedrich and Standaert
INTRASPINAL CYST AND SPONDYLOLYSIS CAUSING RADICULOPATHY
CONCLUSION A synovial cyst related to chronic spondylolysis is a rare cause of lumbar radiculopathy. There is limited information available on the pathogenesis, natural history, and most appropriate treatment for these cysts. It is also uncertain how much can be inferred from the available literature on synovial cysts associated with degenerative lumbar zygapophysial joints, because spondylolysis-related cysts may be a distinctly different problem, particularly when appearing in a young patient. This case demonstrates that subacute clinical and radiologic resolution of such a cyst is possible without surgical intervention in an adolescent patient with sensorimotor radiculopathy.
REFERENCES 1. DePalma MJ, Strakowski JA, Mandelker EM, et al. An instance of an atypical intraspinal cyst presenting as S1 radiculopathy: A case report and brief review of pathophysiology. Arch Phys Med Rehabil 2004;85: 1021-1025.
2. Awwad EE, Sundaram M, Bucholz RD. Post-traumatic spinal synovial cyst with spondylolysis: CT features. J Comput Assist Tomogr 1989;13: 334-337. 3. Duprez T, Mailleux P, Bodart A, et al. Retrodural cysts bridging a bilateral lumbar spondylolysis: A report of two symptomatic cases. J Comput Assist Tomogr 1999;23:534-537. 4. Khan AM, Girardi F. Spinal lumbar synovial cysts. Diagnosis and management challenge. Eur Spine J 2006;15:1176-1182. 5. Standaert CJ, Herring SA, Halpern B, et al. Spondylolysis. Phys Med Rehab Clin N Am 2000;11:785-803. 6. Maldague B, Mathurin P, Maghem J. Facet joint arthrography in lumbar spondylolysis. Radiology 1981;140:29-36. 7. Houten JK, Sanderson SP, Cooper PR. Spontaneous regression of symptomatic lumbar synovial cyst. Report of three cases. J Neurosurg Spine 2003;99:235-238. 8. Lyons MK, Atkinson JL, Wharen RE, et al. Surgical evaluation and management of lumbar synovial cysts: The Mayo Clinic experience. J Neurosurg Spine 2000;93:53-57. 9. Allen TL, Tatli Y, Lutz GE. Fluoroscopic percutaneous lumbar zygapophysial joint cyst rupture: A clinic outcome study. Spine J 2009;9: 387-395. 10. Sabers SR, Ross SR, Grogg BE, et al. Procedure-based nonsurgical management of lumbar zygapophysial joint cyst-induced radicular pain. Arch Phys Med Rehabil 2005;86:1767-1771.