Nonconsecutive Pars Interarticularis Defects

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Nonconsecutive Pars Interarticularis Defects

Spondylolysis is a bone defect of the pars interarticularis. It is usually seen in adolescents who participate in sporting activities that involve repetitive axial loads to a hyperextended lower back, such as football offensive lineman, throwing athletes, and gymnasts. It occurs frequently in the L5 pars and can be unilateral or bilateral. The majority of reported multiple-level spondylolysis is at consecutive lumbar segments.1-6 Rarely, it affects noncontiguous levels. Most patients respond well to conservative treatment in the form of activity modification and orthosis.7 Surgical intervention is considered if 6 months of conservative management fails, spondylolisthesis develops, or intractable neurologic symptoms arise.

This case report presents an 18-year-old man with noncontiguous spondylolysis at L2 and L5 who was successfully treated with a 1-level pars repair at L2 after failed conservative management. This unique case highlights the importance of using single-photon emission computed tomography (SPECT) scan and diagnostic pars block when planning for surgical treatment in the rare cases of noncontiguous spondylolysis. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

An 18-year-old man presented to the clinic with worsening lower back pain for the previous 4 weeks. He was playing high school baseball and stated the pain was worse when he swung his bat. He had no history of trauma or back pain. Rest was the only alleviating factor, and he was beginning to experience pain when he stood after sitting. He denied any radicular pain. On examination, he had midline tenderness along the upper lumbar spine and pain with lumbar spine extension. His neurologic examination showed normal sensation with 5/5 strength in all key muscle groups. Plain radiograph of the lumbar spine showed an L5 pars defect (Figures 1A, 1B). A SPECT scan showed increased uptake at L2 pars bilaterally; the L5 pars did not show increased uptake (Figures 2A, 2B). A computed tomography (CT) scan confirmed bilateral L2 pars fractures and a left L5 pars fracture (Figures 3A, 3B). Bony changes in the form of marginal sclerosis at the L5, but not the L2, pars suggested that the L2 fracture was acute while the L5 fracture was chronic (Figures 4A, 4B).

 

 

The patient had conservative management for 6 months in the form of lumbosacral orthosis (LSO), cessation of sports activities, and physical therapy. The patient was initially treated with an LSO brace for 3 months, after which he had physical therapy. At 6 month follow-up, he reported continuing, significant back pain. A repeat CT scan of the lumbar spine showed no interval healing of the bilateral L2 or the unilateral L5 pars fractures. As a result of the patient’s noncontiguous pars fractures, a diagnostic CT-guided block of L2 pars was performed to identify which level was his main pain generator (Figure 5). He reported a brief period of complete pain relief after the L2 pars block. With failure of 6 months’ conservative management and positive SPECT scan and diagnostic block, surgical treatment was recommended. Prior to surgical intervention, magnetic resonance imaging was obtained to rule out pathology (eg, disc degeneration, infection, or tumor) other than the pars defect that could require fusion instead of pars repair (Figures 6A, 6B). Because of the patient’s young age, bilateral L2 pars repair rather than fusion was indicated. After 8 months of persistent back pain, he underwent bilateral L2 pars repair with iliac crest autograft, pedicle screws, and sublaminar hook fixation (Figures 7A, 7B). The patient had an uneventful immediate postoperative course. A 6-month postoperative CT scan showed bridging callus at the L2 pars; however, the left L5 pars fracture was still visible (Figures 8A-8C). Over a 6-month postoperative period, the patient had continued improvement in his back pain, advanced his activity as tolerated without problem, and was allowed to resume his sports activities. At 2-year follow-up, he was playing baseball and basketball, and denied any back pain. 

 
 
 

Discussion

Lumbar spondylolysis is commonly seen at the fourth and fifth lumbar vertebrae, and accounts for more than 95% of spondylolysis cases.8 Multiple-level spondylolysis is a relatively rare finding with an incidence varying between 1.2% and 5.6%. The majority of the reported multiple-level cases are adjacent.1-3,6 Adolescents often present with a history of insidious-onset low back pain without radicular symptoms that is exacerbated by activity. Occasionally, an acute injury may elicit the onset of pain. A thorough history with emphasis on pain in relation to activity and sports involvement is beneficial. The patient in the current study was a throwing athlete and presented with 4 weeks of back pain that worsened with activity; he had no history of trauma.

 

 

Radiographic assessment using standing anteroposterior, lateral, and oblique radiographs of the thoracolumbar spine is useful in the initial assessment. A SPECT scan of the lumbosacral spine is highly sensitive for identifying spondylolytic defects when plain radiographs are within normal limits, yet a high index of suspicion remains given the patient’s history and physical examination findings.9,10 Increased radionuclide uptake within the pars indicates a stress reaction and, possibly, a more acute pathology. The plain radiographs of the patient showed only L5 spondylolysis. However, a SPECT scan showed only increased uptake in L2 pars on both sides. These findings suggested chronic L5 and acute L2 pars defects. A thin-cut CT scan gives the best visualization of pars defect and can help in differentiating chronic defect with sclerotic margins versus acute defect with hazy irregular margins. In the current case, the CT scan showed changes consistent with unilateral chronic L5 and bilateral acute L2 pars defects.

The origin of the pain in spondylolysis is from the tissues rich in nociceptive nerve endings in the loose posterior arch. A CT-guided pars block is a very useful diagnostic preoperative tool that confirms the symptomatic level in cases of multilevel pars defect, especially if they are noncontiguous. In this case, the diagnostic preoperative bilateral L2 pars block confirmed that the pain generator was the acute L2 rather than the chronic L5 pars defect. This step assured that surgical treatment involving only the L2 level would be beneficial in alleviating the patient’s back pain after the failure of 6 months of conservative treatment.

Most patients with single-level spondylolysis respond to conservative treatment, especially after early diagnosis and treatment. The traditional nonoperative treatment of children and adolescents with a symptomatic spondylolytic lesion was a period of rest and progressive increased activity with physical therapy. Immobilization with an LSO was reserved for individuals who did not respond to rest and physical therapy.11 However, multiple studies revealed early immobilization achieved results superior to activity restriction alone, and individuals who underwent a period of activity restriction prior to bracing were more likely to experience persistent symptoms.12-14 Our patient underwent conservative treatment for 6 months, in the form of LSO, cessation of sport activities, and physical therapy, which failed to give him relief of his back pain.

Surgical intervention is warranted for adolescents with persistent, debilitating pain intractable to at least a 6-month period of nonoperative management. Additional indications for surgical management are those individuals who present with neurologic deficits and isthmic spondylolisthesis. Surgical treatment involves direct pars repair with iliac crest bone graft and use of a sublaminar hook/pedicle screw construct, cerclage wire, or pars screw.15-18 

In contrast to single-level pars defects that respond well to conservative treatment, there are conflicting reports regarding the management of multiple-level pars fractures; a few reports suggest good outcome with conservative management, but the majority state that surgery is often required and conservative measures are rarely useful.1-4,6 Nayeemuddin and colleagues19 reported a case of a 16-year-old football player who presented with a 4-month history of constant low back pain related to bilateral L3 and L5 pars defects that responded to 1 year of conservative management, when the more acute fractures at L3 showed complete bony union and the patient had symptomatic pain relief and was able to return to full sporting activity.

 Chang and colleagues2 reported 10 patients with adjacent 2-level bilateral spondylolysis treated successfully using a pedicle screw–hook construct with autogenous bone grafting. Ogawa and colleagues5 reported adjacent 2-level spondylolysis in 5 patients and 3-level spondylolysis in 2 patients, who were treated successfully by segmental wire fixation and bone grafting. Ivanic and colleagues15 retrospectively reviewed 113 patients with spondylolysis who were treated with direct repair using a hook-screw construct and showed a pseudoarthrosis rate of 13.3%. Superior fusion rates were observed in patients 14 years and younger compared with older patients, particularly those 20 years and older.15 Roca and colleagues16 prospectively analyzed 19 consecutive cases of spondylolysis that were repaired using a hook-screw construct. Twelve of 13 patients (92%) who were 20 years or younger at the time of the study (average age, 17.2 years) had fusion, whereas, in 6 patients 21 years and older (average age, 27.5 years), no cases of fusion were observed. The patients 20 years or younger had significantly better clinical results than those obtained in the patients 21 years and older. The authors concluded that pedicle screw–hook fixation is a useful alternative in the treatment of spondylolysis in adolescents, but did not recommend this procedure in patients older than 20 years.16

 

 

Conclusion

The current case demonstrates a unique example of rare noncontiguous pars defects successfully treated with primary repair of 1 level when conservative management failed and the symptomatic defect was isolated. It also highlights the importance of investigating the entirety of the lumbar spine when diagnosis of L5 spondylolysis rules out noncontiguous pars defects. The treatment of noncontiguous pars defects is not well defined; this case showed the importance of using a SPECT scan and a diagnostic pars block to help isolate the symptomatic level when surgical management is considered after a failure of conservative treatment. This case shows 2 possible results: the chronic unilateral L5 defect responded to nonsurgical treatment with asymptomatic fibrous nonunion, while the more acute bilateral L2 defect responded to pars repair with pedicle screw–hook fixation and iliac crest bone graft. 

References

1.    Al-Sebai MW, Al-Khawashki H. Spondyloptosis and multiple-level spondylolysis. Eur Spine J. 1999;8(1):75-77.

2.    Chang JH, Lee CH, Wu SS, Lin LC, et al. Management of multiple level spondylolysis of the lumbar spine in young males: a report of six cases. J Formos Med Assoc. 2001;100(7)2:497-502.

3.    Eingorn D, Pizzutillo PD. Pars interarticularis fusion of multiple levels of lumbar spondylolysis. A case report. Spine. 1985;10(3):250-252.

4.    Nozawa S, Shimizu K, Miyamoto K, Tanaka M. Repair of pars interarticularis defect by segmental wire fixation in young athletes with spondylolysis. Am J Sports Med. 2003;31(3):359-364.

5.    Ogawa H, Nishimoto H, Hosoe H, Suzuki N, Kanamori Y, Shimizu K. Clinical outcome after segmental wire fixation and bone grafting for repair of the defects in multiple level lumbar spondylolysis. J Spinal Disord Tech. 2007;20(7):521-525.

6.    Ravichandran G. Multiple lumbar spondylolyses. Spine. 1980;5(6):552-557.

7.    Sys J, Michielsen J, Bracke P, Martens M, Verstreken J. Nonoperative treatment of active spondylolysis in elite athletes with normal X-ray findings: literature review and results of conservative treatment. Eur Spine J. 2001;10(6):498-504.

8.    Saraste H. Spondylolysis and spondylolisthesis. Acta Orthop Scand Suppl. 1993;251:84-86.

9.    Anderson K, Sarwark JF, Conway JJ, Logue ES, Schafer MS. Quantitative assessment with SPECT imaging of stress injuries of the pars interarticularis and response to bracing. J Pediatr Orthop. 2000;20(1):28-33.

10.  Bodner RJ, Heyman S, Drummond DS, Gregg JR. The use of single photon emission computed tomography (SPECT) in the diagnosis of low-back pain in young patients. Spine. 1988;13(10):1155-1160.

11.  Steiner ME, Micheli LJ. Treatment of symptomatic spondylolysis and spondylolisthesis with the modified Boston brace. Spine. 1985;10(10):937-943.

12.  Blanda J, Bethem D, Moats W, Lew M. Defects of pars interarticularis in athletes: a protocol for nonoperative treatment. J Spinal Disord. 1993;6(5):406-411.

13.  Kurd MF, Patel D, Norton R, Picetti G, Friel B, Vaccaro AR. Nonoperative treatment of symptomatic spondylolysis. J Spinal Disord Tech. 2007;20(8):560-564.

14.  Pizzutillo PD, Hummer CD 3rd. Nonoperative treatment for painful adolescent spondylolysis or spondylolisthesis. J Pediatr Orthop. 1989;9(5):538-540.

15.  Ivanic GM, Pink TP, Achatz W, Ward JC, Homann NC, May M. Direct stabilization of lumbar spondylolysis with a hook screw: mean 11-year follow-up period for 113 patients. Spine. 2003;28(3):255-259.

16.  Roca J, Iborra M, Cavanilles-Walker JM, Alberti G. Direct repair of spondylolysis using a new pedicle screw hook fixation: clinical and CT-assessed study: an analysis of 19 patients. J Spinal Disord Tech. 2005;18(suppl):S82-S89.

17.  Schlenzka D, Remes V, Helenius I, et al. Direct repair for treatment of symptomatic spondylolysis and low-grade isthmic spondylolisthesis in young patients: no benefit in comparison to segmental fusion after a mean follow-up of 14.8 years. Eur Spine J. 2006;15(10):1437-1447.

18.  Buck JE. Direct repair of the defect in spondylolisthesis. Preliminary report. J Bone Joint Surg Br. 1970;52(3):432-437.

19.  Nayeemuddin M, Richards PJ, Ahmed EB. The imaging and management of nonconsecutive pars interarticularis defects: a case report and review of literature. Spine J. 2011;11(12):1157-1163.

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Hossein Elgafy, MD, FRCSEd, FRCSC, Ryan C. Hart, MD, and Mina Tanios, MD

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american journal of orthopedics, AJO, online exclusive, case report and literature review, case report, pars, interarticularis defects, lumbar spondylolysis, adolescents, pediatrics, spine, fractures, fracture management, pars fracture, back, pain, imaging, elgafy, hart, tanios
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Hossein Elgafy, MD, FRCSEd, FRCSC, Ryan C. Hart, MD, and Mina Tanios, MD

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Spondylolysis is a bone defect of the pars interarticularis. It is usually seen in adolescents who participate in sporting activities that involve repetitive axial loads to a hyperextended lower back, such as football offensive lineman, throwing athletes, and gymnasts. It occurs frequently in the L5 pars and can be unilateral or bilateral. The majority of reported multiple-level spondylolysis is at consecutive lumbar segments.1-6 Rarely, it affects noncontiguous levels. Most patients respond well to conservative treatment in the form of activity modification and orthosis.7 Surgical intervention is considered if 6 months of conservative management fails, spondylolisthesis develops, or intractable neurologic symptoms arise.

This case report presents an 18-year-old man with noncontiguous spondylolysis at L2 and L5 who was successfully treated with a 1-level pars repair at L2 after failed conservative management. This unique case highlights the importance of using single-photon emission computed tomography (SPECT) scan and diagnostic pars block when planning for surgical treatment in the rare cases of noncontiguous spondylolysis. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

An 18-year-old man presented to the clinic with worsening lower back pain for the previous 4 weeks. He was playing high school baseball and stated the pain was worse when he swung his bat. He had no history of trauma or back pain. Rest was the only alleviating factor, and he was beginning to experience pain when he stood after sitting. He denied any radicular pain. On examination, he had midline tenderness along the upper lumbar spine and pain with lumbar spine extension. His neurologic examination showed normal sensation with 5/5 strength in all key muscle groups. Plain radiograph of the lumbar spine showed an L5 pars defect (Figures 1A, 1B). A SPECT scan showed increased uptake at L2 pars bilaterally; the L5 pars did not show increased uptake (Figures 2A, 2B). A computed tomography (CT) scan confirmed bilateral L2 pars fractures and a left L5 pars fracture (Figures 3A, 3B). Bony changes in the form of marginal sclerosis at the L5, but not the L2, pars suggested that the L2 fracture was acute while the L5 fracture was chronic (Figures 4A, 4B).

 

 

The patient had conservative management for 6 months in the form of lumbosacral orthosis (LSO), cessation of sports activities, and physical therapy. The patient was initially treated with an LSO brace for 3 months, after which he had physical therapy. At 6 month follow-up, he reported continuing, significant back pain. A repeat CT scan of the lumbar spine showed no interval healing of the bilateral L2 or the unilateral L5 pars fractures. As a result of the patient’s noncontiguous pars fractures, a diagnostic CT-guided block of L2 pars was performed to identify which level was his main pain generator (Figure 5). He reported a brief period of complete pain relief after the L2 pars block. With failure of 6 months’ conservative management and positive SPECT scan and diagnostic block, surgical treatment was recommended. Prior to surgical intervention, magnetic resonance imaging was obtained to rule out pathology (eg, disc degeneration, infection, or tumor) other than the pars defect that could require fusion instead of pars repair (Figures 6A, 6B). Because of the patient’s young age, bilateral L2 pars repair rather than fusion was indicated. After 8 months of persistent back pain, he underwent bilateral L2 pars repair with iliac crest autograft, pedicle screws, and sublaminar hook fixation (Figures 7A, 7B). The patient had an uneventful immediate postoperative course. A 6-month postoperative CT scan showed bridging callus at the L2 pars; however, the left L5 pars fracture was still visible (Figures 8A-8C). Over a 6-month postoperative period, the patient had continued improvement in his back pain, advanced his activity as tolerated without problem, and was allowed to resume his sports activities. At 2-year follow-up, he was playing baseball and basketball, and denied any back pain. 

 
 
 

Discussion

Lumbar spondylolysis is commonly seen at the fourth and fifth lumbar vertebrae, and accounts for more than 95% of spondylolysis cases.8 Multiple-level spondylolysis is a relatively rare finding with an incidence varying between 1.2% and 5.6%. The majority of the reported multiple-level cases are adjacent.1-3,6 Adolescents often present with a history of insidious-onset low back pain without radicular symptoms that is exacerbated by activity. Occasionally, an acute injury may elicit the onset of pain. A thorough history with emphasis on pain in relation to activity and sports involvement is beneficial. The patient in the current study was a throwing athlete and presented with 4 weeks of back pain that worsened with activity; he had no history of trauma.

 

 

Radiographic assessment using standing anteroposterior, lateral, and oblique radiographs of the thoracolumbar spine is useful in the initial assessment. A SPECT scan of the lumbosacral spine is highly sensitive for identifying spondylolytic defects when plain radiographs are within normal limits, yet a high index of suspicion remains given the patient’s history and physical examination findings.9,10 Increased radionuclide uptake within the pars indicates a stress reaction and, possibly, a more acute pathology. The plain radiographs of the patient showed only L5 spondylolysis. However, a SPECT scan showed only increased uptake in L2 pars on both sides. These findings suggested chronic L5 and acute L2 pars defects. A thin-cut CT scan gives the best visualization of pars defect and can help in differentiating chronic defect with sclerotic margins versus acute defect with hazy irregular margins. In the current case, the CT scan showed changes consistent with unilateral chronic L5 and bilateral acute L2 pars defects.

The origin of the pain in spondylolysis is from the tissues rich in nociceptive nerve endings in the loose posterior arch. A CT-guided pars block is a very useful diagnostic preoperative tool that confirms the symptomatic level in cases of multilevel pars defect, especially if they are noncontiguous. In this case, the diagnostic preoperative bilateral L2 pars block confirmed that the pain generator was the acute L2 rather than the chronic L5 pars defect. This step assured that surgical treatment involving only the L2 level would be beneficial in alleviating the patient’s back pain after the failure of 6 months of conservative treatment.

Most patients with single-level spondylolysis respond to conservative treatment, especially after early diagnosis and treatment. The traditional nonoperative treatment of children and adolescents with a symptomatic spondylolytic lesion was a period of rest and progressive increased activity with physical therapy. Immobilization with an LSO was reserved for individuals who did not respond to rest and physical therapy.11 However, multiple studies revealed early immobilization achieved results superior to activity restriction alone, and individuals who underwent a period of activity restriction prior to bracing were more likely to experience persistent symptoms.12-14 Our patient underwent conservative treatment for 6 months, in the form of LSO, cessation of sport activities, and physical therapy, which failed to give him relief of his back pain.

Surgical intervention is warranted for adolescents with persistent, debilitating pain intractable to at least a 6-month period of nonoperative management. Additional indications for surgical management are those individuals who present with neurologic deficits and isthmic spondylolisthesis. Surgical treatment involves direct pars repair with iliac crest bone graft and use of a sublaminar hook/pedicle screw construct, cerclage wire, or pars screw.15-18 

In contrast to single-level pars defects that respond well to conservative treatment, there are conflicting reports regarding the management of multiple-level pars fractures; a few reports suggest good outcome with conservative management, but the majority state that surgery is often required and conservative measures are rarely useful.1-4,6 Nayeemuddin and colleagues19 reported a case of a 16-year-old football player who presented with a 4-month history of constant low back pain related to bilateral L3 and L5 pars defects that responded to 1 year of conservative management, when the more acute fractures at L3 showed complete bony union and the patient had symptomatic pain relief and was able to return to full sporting activity.

 Chang and colleagues2 reported 10 patients with adjacent 2-level bilateral spondylolysis treated successfully using a pedicle screw–hook construct with autogenous bone grafting. Ogawa and colleagues5 reported adjacent 2-level spondylolysis in 5 patients and 3-level spondylolysis in 2 patients, who were treated successfully by segmental wire fixation and bone grafting. Ivanic and colleagues15 retrospectively reviewed 113 patients with spondylolysis who were treated with direct repair using a hook-screw construct and showed a pseudoarthrosis rate of 13.3%. Superior fusion rates were observed in patients 14 years and younger compared with older patients, particularly those 20 years and older.15 Roca and colleagues16 prospectively analyzed 19 consecutive cases of spondylolysis that were repaired using a hook-screw construct. Twelve of 13 patients (92%) who were 20 years or younger at the time of the study (average age, 17.2 years) had fusion, whereas, in 6 patients 21 years and older (average age, 27.5 years), no cases of fusion were observed. The patients 20 years or younger had significantly better clinical results than those obtained in the patients 21 years and older. The authors concluded that pedicle screw–hook fixation is a useful alternative in the treatment of spondylolysis in adolescents, but did not recommend this procedure in patients older than 20 years.16

 

 

Conclusion

The current case demonstrates a unique example of rare noncontiguous pars defects successfully treated with primary repair of 1 level when conservative management failed and the symptomatic defect was isolated. It also highlights the importance of investigating the entirety of the lumbar spine when diagnosis of L5 spondylolysis rules out noncontiguous pars defects. The treatment of noncontiguous pars defects is not well defined; this case showed the importance of using a SPECT scan and a diagnostic pars block to help isolate the symptomatic level when surgical management is considered after a failure of conservative treatment. This case shows 2 possible results: the chronic unilateral L5 defect responded to nonsurgical treatment with asymptomatic fibrous nonunion, while the more acute bilateral L2 defect responded to pars repair with pedicle screw–hook fixation and iliac crest bone graft. 

Spondylolysis is a bone defect of the pars interarticularis. It is usually seen in adolescents who participate in sporting activities that involve repetitive axial loads to a hyperextended lower back, such as football offensive lineman, throwing athletes, and gymnasts. It occurs frequently in the L5 pars and can be unilateral or bilateral. The majority of reported multiple-level spondylolysis is at consecutive lumbar segments.1-6 Rarely, it affects noncontiguous levels. Most patients respond well to conservative treatment in the form of activity modification and orthosis.7 Surgical intervention is considered if 6 months of conservative management fails, spondylolisthesis develops, or intractable neurologic symptoms arise.

This case report presents an 18-year-old man with noncontiguous spondylolysis at L2 and L5 who was successfully treated with a 1-level pars repair at L2 after failed conservative management. This unique case highlights the importance of using single-photon emission computed tomography (SPECT) scan and diagnostic pars block when planning for surgical treatment in the rare cases of noncontiguous spondylolysis. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

An 18-year-old man presented to the clinic with worsening lower back pain for the previous 4 weeks. He was playing high school baseball and stated the pain was worse when he swung his bat. He had no history of trauma or back pain. Rest was the only alleviating factor, and he was beginning to experience pain when he stood after sitting. He denied any radicular pain. On examination, he had midline tenderness along the upper lumbar spine and pain with lumbar spine extension. His neurologic examination showed normal sensation with 5/5 strength in all key muscle groups. Plain radiograph of the lumbar spine showed an L5 pars defect (Figures 1A, 1B). A SPECT scan showed increased uptake at L2 pars bilaterally; the L5 pars did not show increased uptake (Figures 2A, 2B). A computed tomography (CT) scan confirmed bilateral L2 pars fractures and a left L5 pars fracture (Figures 3A, 3B). Bony changes in the form of marginal sclerosis at the L5, but not the L2, pars suggested that the L2 fracture was acute while the L5 fracture was chronic (Figures 4A, 4B).

 

 

The patient had conservative management for 6 months in the form of lumbosacral orthosis (LSO), cessation of sports activities, and physical therapy. The patient was initially treated with an LSO brace for 3 months, after which he had physical therapy. At 6 month follow-up, he reported continuing, significant back pain. A repeat CT scan of the lumbar spine showed no interval healing of the bilateral L2 or the unilateral L5 pars fractures. As a result of the patient’s noncontiguous pars fractures, a diagnostic CT-guided block of L2 pars was performed to identify which level was his main pain generator (Figure 5). He reported a brief period of complete pain relief after the L2 pars block. With failure of 6 months’ conservative management and positive SPECT scan and diagnostic block, surgical treatment was recommended. Prior to surgical intervention, magnetic resonance imaging was obtained to rule out pathology (eg, disc degeneration, infection, or tumor) other than the pars defect that could require fusion instead of pars repair (Figures 6A, 6B). Because of the patient’s young age, bilateral L2 pars repair rather than fusion was indicated. After 8 months of persistent back pain, he underwent bilateral L2 pars repair with iliac crest autograft, pedicle screws, and sublaminar hook fixation (Figures 7A, 7B). The patient had an uneventful immediate postoperative course. A 6-month postoperative CT scan showed bridging callus at the L2 pars; however, the left L5 pars fracture was still visible (Figures 8A-8C). Over a 6-month postoperative period, the patient had continued improvement in his back pain, advanced his activity as tolerated without problem, and was allowed to resume his sports activities. At 2-year follow-up, he was playing baseball and basketball, and denied any back pain. 

 
 
 

Discussion

Lumbar spondylolysis is commonly seen at the fourth and fifth lumbar vertebrae, and accounts for more than 95% of spondylolysis cases.8 Multiple-level spondylolysis is a relatively rare finding with an incidence varying between 1.2% and 5.6%. The majority of the reported multiple-level cases are adjacent.1-3,6 Adolescents often present with a history of insidious-onset low back pain without radicular symptoms that is exacerbated by activity. Occasionally, an acute injury may elicit the onset of pain. A thorough history with emphasis on pain in relation to activity and sports involvement is beneficial. The patient in the current study was a throwing athlete and presented with 4 weeks of back pain that worsened with activity; he had no history of trauma.

 

 

Radiographic assessment using standing anteroposterior, lateral, and oblique radiographs of the thoracolumbar spine is useful in the initial assessment. A SPECT scan of the lumbosacral spine is highly sensitive for identifying spondylolytic defects when plain radiographs are within normal limits, yet a high index of suspicion remains given the patient’s history and physical examination findings.9,10 Increased radionuclide uptake within the pars indicates a stress reaction and, possibly, a more acute pathology. The plain radiographs of the patient showed only L5 spondylolysis. However, a SPECT scan showed only increased uptake in L2 pars on both sides. These findings suggested chronic L5 and acute L2 pars defects. A thin-cut CT scan gives the best visualization of pars defect and can help in differentiating chronic defect with sclerotic margins versus acute defect with hazy irregular margins. In the current case, the CT scan showed changes consistent with unilateral chronic L5 and bilateral acute L2 pars defects.

The origin of the pain in spondylolysis is from the tissues rich in nociceptive nerve endings in the loose posterior arch. A CT-guided pars block is a very useful diagnostic preoperative tool that confirms the symptomatic level in cases of multilevel pars defect, especially if they are noncontiguous. In this case, the diagnostic preoperative bilateral L2 pars block confirmed that the pain generator was the acute L2 rather than the chronic L5 pars defect. This step assured that surgical treatment involving only the L2 level would be beneficial in alleviating the patient’s back pain after the failure of 6 months of conservative treatment.

Most patients with single-level spondylolysis respond to conservative treatment, especially after early diagnosis and treatment. The traditional nonoperative treatment of children and adolescents with a symptomatic spondylolytic lesion was a period of rest and progressive increased activity with physical therapy. Immobilization with an LSO was reserved for individuals who did not respond to rest and physical therapy.11 However, multiple studies revealed early immobilization achieved results superior to activity restriction alone, and individuals who underwent a period of activity restriction prior to bracing were more likely to experience persistent symptoms.12-14 Our patient underwent conservative treatment for 6 months, in the form of LSO, cessation of sport activities, and physical therapy, which failed to give him relief of his back pain.

Surgical intervention is warranted for adolescents with persistent, debilitating pain intractable to at least a 6-month period of nonoperative management. Additional indications for surgical management are those individuals who present with neurologic deficits and isthmic spondylolisthesis. Surgical treatment involves direct pars repair with iliac crest bone graft and use of a sublaminar hook/pedicle screw construct, cerclage wire, or pars screw.15-18 

In contrast to single-level pars defects that respond well to conservative treatment, there are conflicting reports regarding the management of multiple-level pars fractures; a few reports suggest good outcome with conservative management, but the majority state that surgery is often required and conservative measures are rarely useful.1-4,6 Nayeemuddin and colleagues19 reported a case of a 16-year-old football player who presented with a 4-month history of constant low back pain related to bilateral L3 and L5 pars defects that responded to 1 year of conservative management, when the more acute fractures at L3 showed complete bony union and the patient had symptomatic pain relief and was able to return to full sporting activity.

 Chang and colleagues2 reported 10 patients with adjacent 2-level bilateral spondylolysis treated successfully using a pedicle screw–hook construct with autogenous bone grafting. Ogawa and colleagues5 reported adjacent 2-level spondylolysis in 5 patients and 3-level spondylolysis in 2 patients, who were treated successfully by segmental wire fixation and bone grafting. Ivanic and colleagues15 retrospectively reviewed 113 patients with spondylolysis who were treated with direct repair using a hook-screw construct and showed a pseudoarthrosis rate of 13.3%. Superior fusion rates were observed in patients 14 years and younger compared with older patients, particularly those 20 years and older.15 Roca and colleagues16 prospectively analyzed 19 consecutive cases of spondylolysis that were repaired using a hook-screw construct. Twelve of 13 patients (92%) who were 20 years or younger at the time of the study (average age, 17.2 years) had fusion, whereas, in 6 patients 21 years and older (average age, 27.5 years), no cases of fusion were observed. The patients 20 years or younger had significantly better clinical results than those obtained in the patients 21 years and older. The authors concluded that pedicle screw–hook fixation is a useful alternative in the treatment of spondylolysis in adolescents, but did not recommend this procedure in patients older than 20 years.16

 

 

Conclusion

The current case demonstrates a unique example of rare noncontiguous pars defects successfully treated with primary repair of 1 level when conservative management failed and the symptomatic defect was isolated. It also highlights the importance of investigating the entirety of the lumbar spine when diagnosis of L5 spondylolysis rules out noncontiguous pars defects. The treatment of noncontiguous pars defects is not well defined; this case showed the importance of using a SPECT scan and a diagnostic pars block to help isolate the symptomatic level when surgical management is considered after a failure of conservative treatment. This case shows 2 possible results: the chronic unilateral L5 defect responded to nonsurgical treatment with asymptomatic fibrous nonunion, while the more acute bilateral L2 defect responded to pars repair with pedicle screw–hook fixation and iliac crest bone graft. 

References

1.    Al-Sebai MW, Al-Khawashki H. Spondyloptosis and multiple-level spondylolysis. Eur Spine J. 1999;8(1):75-77.

2.    Chang JH, Lee CH, Wu SS, Lin LC, et al. Management of multiple level spondylolysis of the lumbar spine in young males: a report of six cases. J Formos Med Assoc. 2001;100(7)2:497-502.

3.    Eingorn D, Pizzutillo PD. Pars interarticularis fusion of multiple levels of lumbar spondylolysis. A case report. Spine. 1985;10(3):250-252.

4.    Nozawa S, Shimizu K, Miyamoto K, Tanaka M. Repair of pars interarticularis defect by segmental wire fixation in young athletes with spondylolysis. Am J Sports Med. 2003;31(3):359-364.

5.    Ogawa H, Nishimoto H, Hosoe H, Suzuki N, Kanamori Y, Shimizu K. Clinical outcome after segmental wire fixation and bone grafting for repair of the defects in multiple level lumbar spondylolysis. J Spinal Disord Tech. 2007;20(7):521-525.

6.    Ravichandran G. Multiple lumbar spondylolyses. Spine. 1980;5(6):552-557.

7.    Sys J, Michielsen J, Bracke P, Martens M, Verstreken J. Nonoperative treatment of active spondylolysis in elite athletes with normal X-ray findings: literature review and results of conservative treatment. Eur Spine J. 2001;10(6):498-504.

8.    Saraste H. Spondylolysis and spondylolisthesis. Acta Orthop Scand Suppl. 1993;251:84-86.

9.    Anderson K, Sarwark JF, Conway JJ, Logue ES, Schafer MS. Quantitative assessment with SPECT imaging of stress injuries of the pars interarticularis and response to bracing. J Pediatr Orthop. 2000;20(1):28-33.

10.  Bodner RJ, Heyman S, Drummond DS, Gregg JR. The use of single photon emission computed tomography (SPECT) in the diagnosis of low-back pain in young patients. Spine. 1988;13(10):1155-1160.

11.  Steiner ME, Micheli LJ. Treatment of symptomatic spondylolysis and spondylolisthesis with the modified Boston brace. Spine. 1985;10(10):937-943.

12.  Blanda J, Bethem D, Moats W, Lew M. Defects of pars interarticularis in athletes: a protocol for nonoperative treatment. J Spinal Disord. 1993;6(5):406-411.

13.  Kurd MF, Patel D, Norton R, Picetti G, Friel B, Vaccaro AR. Nonoperative treatment of symptomatic spondylolysis. J Spinal Disord Tech. 2007;20(8):560-564.

14.  Pizzutillo PD, Hummer CD 3rd. Nonoperative treatment for painful adolescent spondylolysis or spondylolisthesis. J Pediatr Orthop. 1989;9(5):538-540.

15.  Ivanic GM, Pink TP, Achatz W, Ward JC, Homann NC, May M. Direct stabilization of lumbar spondylolysis with a hook screw: mean 11-year follow-up period for 113 patients. Spine. 2003;28(3):255-259.

16.  Roca J, Iborra M, Cavanilles-Walker JM, Alberti G. Direct repair of spondylolysis using a new pedicle screw hook fixation: clinical and CT-assessed study: an analysis of 19 patients. J Spinal Disord Tech. 2005;18(suppl):S82-S89.

17.  Schlenzka D, Remes V, Helenius I, et al. Direct repair for treatment of symptomatic spondylolysis and low-grade isthmic spondylolisthesis in young patients: no benefit in comparison to segmental fusion after a mean follow-up of 14.8 years. Eur Spine J. 2006;15(10):1437-1447.

18.  Buck JE. Direct repair of the defect in spondylolisthesis. Preliminary report. J Bone Joint Surg Br. 1970;52(3):432-437.

19.  Nayeemuddin M, Richards PJ, Ahmed EB. The imaging and management of nonconsecutive pars interarticularis defects: a case report and review of literature. Spine J. 2011;11(12):1157-1163.

References

1.    Al-Sebai MW, Al-Khawashki H. Spondyloptosis and multiple-level spondylolysis. Eur Spine J. 1999;8(1):75-77.

2.    Chang JH, Lee CH, Wu SS, Lin LC, et al. Management of multiple level spondylolysis of the lumbar spine in young males: a report of six cases. J Formos Med Assoc. 2001;100(7)2:497-502.

3.    Eingorn D, Pizzutillo PD. Pars interarticularis fusion of multiple levels of lumbar spondylolysis. A case report. Spine. 1985;10(3):250-252.

4.    Nozawa S, Shimizu K, Miyamoto K, Tanaka M. Repair of pars interarticularis defect by segmental wire fixation in young athletes with spondylolysis. Am J Sports Med. 2003;31(3):359-364.

5.    Ogawa H, Nishimoto H, Hosoe H, Suzuki N, Kanamori Y, Shimizu K. Clinical outcome after segmental wire fixation and bone grafting for repair of the defects in multiple level lumbar spondylolysis. J Spinal Disord Tech. 2007;20(7):521-525.

6.    Ravichandran G. Multiple lumbar spondylolyses. Spine. 1980;5(6):552-557.

7.    Sys J, Michielsen J, Bracke P, Martens M, Verstreken J. Nonoperative treatment of active spondylolysis in elite athletes with normal X-ray findings: literature review and results of conservative treatment. Eur Spine J. 2001;10(6):498-504.

8.    Saraste H. Spondylolysis and spondylolisthesis. Acta Orthop Scand Suppl. 1993;251:84-86.

9.    Anderson K, Sarwark JF, Conway JJ, Logue ES, Schafer MS. Quantitative assessment with SPECT imaging of stress injuries of the pars interarticularis and response to bracing. J Pediatr Orthop. 2000;20(1):28-33.

10.  Bodner RJ, Heyman S, Drummond DS, Gregg JR. The use of single photon emission computed tomography (SPECT) in the diagnosis of low-back pain in young patients. Spine. 1988;13(10):1155-1160.

11.  Steiner ME, Micheli LJ. Treatment of symptomatic spondylolysis and spondylolisthesis with the modified Boston brace. Spine. 1985;10(10):937-943.

12.  Blanda J, Bethem D, Moats W, Lew M. Defects of pars interarticularis in athletes: a protocol for nonoperative treatment. J Spinal Disord. 1993;6(5):406-411.

13.  Kurd MF, Patel D, Norton R, Picetti G, Friel B, Vaccaro AR. Nonoperative treatment of symptomatic spondylolysis. J Spinal Disord Tech. 2007;20(8):560-564.

14.  Pizzutillo PD, Hummer CD 3rd. Nonoperative treatment for painful adolescent spondylolysis or spondylolisthesis. J Pediatr Orthop. 1989;9(5):538-540.

15.  Ivanic GM, Pink TP, Achatz W, Ward JC, Homann NC, May M. Direct stabilization of lumbar spondylolysis with a hook screw: mean 11-year follow-up period for 113 patients. Spine. 2003;28(3):255-259.

16.  Roca J, Iborra M, Cavanilles-Walker JM, Alberti G. Direct repair of spondylolysis using a new pedicle screw hook fixation: clinical and CT-assessed study: an analysis of 19 patients. J Spinal Disord Tech. 2005;18(suppl):S82-S89.

17.  Schlenzka D, Remes V, Helenius I, et al. Direct repair for treatment of symptomatic spondylolysis and low-grade isthmic spondylolisthesis in young patients: no benefit in comparison to segmental fusion after a mean follow-up of 14.8 years. Eur Spine J. 2006;15(10):1437-1447.

18.  Buck JE. Direct repair of the defect in spondylolisthesis. Preliminary report. J Bone Joint Surg Br. 1970;52(3):432-437.

19.  Nayeemuddin M, Richards PJ, Ahmed EB. The imaging and management of nonconsecutive pars interarticularis defects: a case report and review of literature. Spine J. 2011;11(12):1157-1163.

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The American Journal of Orthopedics - 44(12)
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The American Journal of Orthopedics - 44(12)
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E526-E529
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E526-E529
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Nonconsecutive Pars Interarticularis Defects
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Nonconsecutive Pars Interarticularis Defects
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american journal of orthopedics, AJO, online exclusive, case report and literature review, case report, pars, interarticularis defects, lumbar spondylolysis, adolescents, pediatrics, spine, fractures, fracture management, pars fracture, back, pain, imaging, elgafy, hart, tanios
Legacy Keywords
american journal of orthopedics, AJO, online exclusive, case report and literature review, case report, pars, interarticularis defects, lumbar spondylolysis, adolescents, pediatrics, spine, fractures, fracture management, pars fracture, back, pain, imaging, elgafy, hart, tanios
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