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Precision Treatment of Adult Lumbar Degenerative Scoliosis Complicated by Lumbar Stenosis with the Use of Selective Nerve Root Block
Original Article
Precision Treatment of Adult Lumbar Degenerative Scoliosis Complicated by Lumbar Stenosis with the Use of Selective Nerve Root Block Yan Liang1, Yongfei Zhao2, Tianhao Wang2, Zhenqi Zhu1, Haiying Liu1, Keya Mao2
BACKGROUND: Use of short-segment or long-segment fusion is controversial in treatment of adult lumbar degenerative scoliosis (ALDS). The aim of this study was to explore efficacy and feasibility of precision treatment of ALDS with selective nerve root block.
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METHODS: From January 2014 to January 2016, a retrospective study of 23 patients with ALDS treated with precision short-segment surgery with at least 2-year follow-up was performed. Fixation segment was determined by selective nerve root block. Visual analog scale and Oswestry Disability Index (ODI) were evaluated preoperatively and at 2-year follow-up. Radiographic measurements included Cobb angle of lumbar curve, lumbar lordosis, sacrum slope, and pelvic tilt. Radiographic evaluation of fusion integrity was performed based on Bridwell interbody fusion grading system at final follow-up.
CONCLUSIONS: Precision treatment of ALDS with selective nerve root block can achieve favorable clinical outcomes and good fusion with less surgical injury and low complications. Deformity correction is limited, which requires further study.
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RESULTS: Mean follow-up time was 25.2 1.4 months. Average lumbar curve was 21.6 7.4 preoperatively and 11.2 6.5 at final follow-up (P < 0.01), with correction rate of 48.1%. Lumbar lordosis changed from L37.1 12.9 to L42.1 10.5 at final follow-up (P < 0.01). Mean visual analog scale back pain scores decreased from 6.0 1.8 preoperatively to 1.5 0.8 at final follow-up (P < 0.01), and mean visual analog scale leg pain scores decreased from 8.1 0.6 preoperatively to 1.3 1.3 at final follow-up (P < 0.01). Oswestry Disability Index score improved from 60.9% 15.7% preoperatively to 22.1% 11.6% at final follow-up (P < 0.01). All patients achieved grade I fusion at final evaluation. One patient (4%) needed further surgical intervention.
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Key words - Adult lumbar degenerative scoliosis - Elective nerve root block - Precision treatment Abbreviations and Acronyms ALDS: Adult lumbar degenerative scoliosis ASD: Adjacent segment disease ODI: Oswestry Disability Index VAS: Visual analog scale
INTRODUCTION
A
dult lumbar degenerative scoliosis (ALDS) is defined as a curve >10 resulting from degeneration of the facets and discs.1 The prevalence of ALDS is 8.3%e68%, and the condition is commonly complicated by advanced age, osteoporosis, cardiopulmonary insufficiency, and other medical comorbidities.2,3 The pathophysiology of ALDS involves asymmetric degeneration of disc and facet joints that puts an asymmetric load on the spine, which leads to degenerative scoliosis.4 The clinical symptoms of ALDS are diverse and include back pain, radiating pain to the legs, and deformity.5 The goals of surgery are to relieve back pain, improve radiating pain and claudication, and correct deformity. Clinically, the surgical procedures commonly include decompression alone, decompression and short-segment fusion, and decompression and long-segment fusion with correction of deformity.6,7 However, there are no clear guidelines regarding which surgical procedure yields the best results in different patients.8,9 Thus, surgery should be selected with consideration of the advantages and disadvantages of each surgical option. Long-segment fusion may induce excessive blood loss and prolonged operative time while achieving a good clinical outcome and deformity correction, which will lead to more postoperative complications. The short-segment fusion is selected based on the patient’s medical condition, and several minimally invasive methods of treatment for
From the 1Department of Spinal Surgery, Peking University People’s Hospital; and 2 Orthopedic Department, the PLA General Hospital (301 Hospital), Beijing, China To whom correspondence should be addressed: Keya Mao, M.D.; Haiying Liu, M.D. [E-mail: [email protected]; [email protected]] Yan Liang and Yongfei Zhao are coefirst authors. Citation: World Neurosurg. (2018). https://doi.org/10.1016/j.wneu.2018.08.205 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
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ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
ALDS have been advocated.10-12 However, limited surgery cannot alleviate the symptoms if performed improperly. The key point is to identify the exact level of fixation and fusion. Therefore, we use a selective nerve root block to determine the course of the surgery. The purpose of this study was to introduce our experiences and explore the efficacy and feasibility of precision treatment of ALDS with the use of selective nerve root block. MATERIALS AND METHODS Patients This study was approved by the institutional review boards of the authors’ affiliated institutions, and all patients gave informed consent to participate in the study. From January 2014 to January 2016, 57 consecutive patients with ALDS who underwent surgery in our hospital were retrospectively analyzed. The clinical presentations of the patients included back pain, intractable unilateral radicular pain, and intermittent claudication. Inclusion criteria were 1) Cobb angle >10 ; 2) posterior-only procedure for adult scoliosis correction; 3) short fusion (limited to 1e3 segments); 4) availability of radiographic examinations (full-length anteroposterior and lateral radiographs) and clinical data (inpatient medical records and questionnaire); and 5) use of nonoperative therapies, including bracing, rest, physiotherapy, and analgesics, without adequate relief of symptoms. Exclusion criteria were 1) idiopathic curves; 2) prior lumbar fusion surgery; and 3) other comorbidities, such as neoplasia, trauma, and infection. Of 57 patients, 23 (40%) were matched with the inclusion criteria (7 men, 16 women; age 63.6 7.4 years). Mean follow-up time was 25.2 1.4 months (range, 24e28 months). Surgical Treatment The fixation and fusion segments were decided by the nerve root block. Before surgery, all patients were treated with nerve root block to confirm the level where the pain originated. If 1 or 2 levels were involved, the surgery was performed without considering the location of the instrumented vertebra. If 3 levels were involved, the fusion was not stopped at the apex of curvature, the vertebra of spondylolisthesis and lateral subluxation, and the thoracolumbar vertebra in patients with thoracolumbar kyphosis. If the 3-level nerve root block was not effective, long-segment fixation and fusion was considered (Figure 1). Data Collection Study measures were obtained through review of inpatient medical records and questionnaires completed by the patients. The primary measures of this study were blood loss, operative time, time to ambulation, postoperative hospital stay, and complications. The complications were categorized as early (within 3 months after surgery) or late postoperative complications.7 Clinical evaluations, which included visual analog scale (VAS) scores for back and leg pain and the Oswestry Disability Index (ODI), were performed preoperatively, postoperatively, and at every follow-up. Preoperative radiologic examination consisted of full-length anteroposterior and lateral radiographs, flexion/extension views, and left and right oblique views. Computed tomography or magnetic resonance imaging was performed to assess the degree and main cause of spinal stenosis and the cause of radiculopathy. Full-length
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anteroposterior and lateral radiographs were obtained postoperatively and at follow-up. Radiographic assessment consisted of Cobb angle of lumbar curve according to the Cobb method (using the maximally angled end vertebra of the coronal curve), lumbar lordosis (L5-S1), sacrum slope, pelvic tilt, and fusion status based on Bridwell interbody fusion grading system, as follows: I, fused with remodeling and trabeculae present; II, graft intact, not fully remodeled and incorporated, but no lucency present; III, graft intact, potential lucency present at top and bottom of graft; IV, fusion absent with collapse and/or resorption of graft. The assessments were performed by 2 independent assessors. Statistical Analysis Data were expressed as mean SD for variables. Preoperative and postoperative differences were calculated using paired t test, and statistical significance was set at P < 0.01. All analyses were carried out using SPSS Version 17 (SPSS, Inc., Chicago, Illinois, USA. RESULTS Surgical Results There were 34 levels treated (mean, 3 segments), including 1 level in 17 patients, which were operated by minimally invasive transforaminal lumbar interbody fusion, and 2 levels in 3 patients and 3 levels in 3 patients, which were operated by open transforaminal lumbar interbody fusion. The primary symptoms were as follows: severe back pain, intractable unilateral radicular pain, and intermittent claudication in 12 patients; mild to moderate back pain, intractable unilateral radicular pain, and intermittent claudication in 8 patients; intractable unilateral radicular pain and intermittent claudication without back pain in 3 patients. The most common level was L4-5 (59%), followed by L3-4 (24%). Transforaminal lumbar interbody fusion and interbody fusion with autogenous bone were performed in all cases. The average operative time was 156.9 26.9 minutes (range, 105e220 minutes) with a mean intraoperative blood loss of 194.6 96.5 mL (range, 75e350 mL). The average hospital stay was 5.7 1.2 days (range, 4e8 days). The average time to ambulation was 2.7 1.0 days (range, 1e4 days) postoperatively. Clinical Results The assessments of VAS pain scores (back and leg) and ODI demonstrated significant clinical differences in preoperatively, postoperatively, and at final follow-up (P < 0.01 and P < 0.01, respectively). A significant difference in the VAS scores or ODI was found between the postoperative and final follow-up assessments (P < 0.01) (Table 1). Radiologic Results The mean Cobb angle decreased from 21.6 7.4 preoperatively to 10.6 6.7 postoperatively with a mean correction of 11 (P < 0.05). The Cobb angle at the final follow-up was 11.2 6.5 , and there was not a statistically significant difference in terms of postoperative and final follow-up results (P > 0.01). For lumbar lordosis, pelvic tilt, and sacrum slope, an obvious difference was found between preoperative and postoperative values (P < 0.01). There was also a significant difference between preoperative and final follow-up values (P < 0.01). No significant differences were observed between
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.08.205
ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
Figure 1. A 53-year-old man with adult lumbar degenerative scoliosis. (AeH) Preoperative x-rays, computed tomography, and magnetic
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resonance imaging. (I and J) Nerve root block surgery. (K and L) Postoperative x-rays. (M and N) X-rays obtained at 2-year follow-up.
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ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
Table 1. Radiographic and Clinical Outcomes in 23 Patients Variables Cobb,
Preoperative
Postoperative
Final Follow-Up
21.6 7.4
10.6 6.7*
11.2 6.5*y
37.1 12.9
42.4 10.8*
42.1 10.5*y
SS,
27.5 8.4
32.7 7.3*
32.9 6.5*y
PT,
20.7 5.7
15.7 6.8*
15.6 5.9*y
VAS back pain score
6.0 1.8
2.3 0.8*
1.5 0.8*z
VAS leg pain score
8.1 0.6
2.9 0.7*
1.3 1.3*z
60.9 15.7
23.9 8.7*
18.9 7.1*z
LL,
ODI, %
LL, lumbar lordosis; SS, sacrum slope; PT, pelvic tilt; VAS, visual analog scale; ODI, Oswestry Disability Index. *P < 0.01 compared with preoperatively. yP > 0.01 compared with postoperatively. zP < 0.01 compared with postoperatively.
postoperative and final follow-up values (P > 0.01) (Table 1). All patients achieved grade I fusion at the final follow-up according to radiologic evidence. No obvious loss of correction occurred in any of the patients. Complications Early Complications. There were 2 dural tears with cerebrospinal fluid leakage, which were repaired during surgery without other special treatment. One patient had pneumonia and recovered after antibiotic treatment. One patient had fat liquefaction of the incision and recovered after débridement. Late Complications One patient had adjacent segment disease (ASD), which was treated with percutaneous endoscopic discectomy. No complications of neurologic injury or nonunion occurred. No screw or rod breakage or failure occurred. DISCUSSION ALDS is usually caused by degeneration and instability of the spine, and the prevalence and curves increase with age. The symptoms of adult scoliosis are diverse and the relationship between symptoms and deformity is complex, which make surgery challenging. The treatment of ALDS has been controversial.13,14 There are many questions concerning the management of patients with ALDS, and great efforts have been directed toward a more standardized approach to such patients. However, there is no consensus on what is the best choice. The main clinical sign of ALDS is deformity, so many surgeons choose long-segment fusion to correct the deformity. Regarding the choice of the proximal fusion level, Shufflebarger et al.15 suggested that fusion at T10 or higher could prevent ASD because T10 has a true rib that can reinforce the thoracolumbar junction. Cho et al.16 also stated that horizontal or neutral vertebra may help to determine the proximal fusion level, and fusion to T10 is more stable than fusion to T11-L1. Regarding distal fusion, Polly et al.17 stated that fusion to L5 may result in high rates of revision and
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suggested distal fusion to S1.18,19 Long-segment fusion can achieve better deformity correction and global balance. However, an excessive fusion level may result in increased bleeding and a longer operative time, which, together with advanced age of the patient and medical comorbidities, increase the complication rate and the cost of surgery. Moreover, long-segment fusion results in fewer mobile segments and decreased spinal range of motion, which brings many inconveniences to patients. To combat these challenges, short-segment fusion has been developed for treatment of ALDS, which has reduced intraoperative blood loss, lower infection rates, and quicker mobilization.20-23 Hwang et al.24 reported that short-segment fusion achieved a good clinical outcome, and the scoliotic angle does not seriously deteriorate in patients with ALDS. Wang et al.25 found that short-segment fusion resulted in limited correction, with the incidence of ASD not as high as reported previously. With short-segment fusion, correction of deformity is not adequate; however, the goal of surgery is not only to correct deformity but also to minimize complications. When choosing surgical options, surgeons should consider the patient’s general condition in weighing the benefits of surgery and risks of complications. The main goal is to solve the symptom rather than restore the alignment. Therefore, we advocate precision treatment of ALDS. The clinical presentations of patients with ALDS include back pain, radiating pain, neurologic symptoms, and deformity. Although deformity is the primary symptom, low back pain and neurologic symptoms are chief complaints in such patients. Neurologic symptoms caused by spinal stenosis that generally involves a short segment of the spine can be treated by shortsegment decompression and fusion. Low back pain is an important consideration for the choice of surgery strategy. Low back pain in patients with ALDS usually results from 2 pathologic abnormalities. One pathology is caused by degenerative changes in the lumbar disc and facet joint. The protruded disc, dystrophy of the ligament flavum, and other inflammatory tissue stimulate the sinuvertebral nerves, spinal nerve posterolateral branch, and other nerve branches to cause low back pain. The other pathology is mechanical low back pain, which is caused by abnormal spine alignment and muscle fatigue induced by spinal imbalance. Therefore, it is a challenge to distinguish and choose the optimal surgery to treat low back pain in patients with ALDS. Selective nerve root block is a minimally invasive punch block technique for nerve root pain performed under video guidance, which serves as diagnosis and treatment. Anderberg et al.26 reported that 45%e100% of nerve root pain can be diagnosed by nerve root block. Therefore, we applied nerve root block to the treatment of ALDS. In patients with ALDS, the neurologic symptoms and low back pain caused by degenerative changes can be effectively treated by nerve root block. In this way, we not only can identify the responsible level but also can perform precision short-segment fusion in these patients. Although the procedure may not be effective in relieving mechanical low back pain, this symptom is only a small part of the patient’s clinical presentation. Moreover, owing to the complexity of ALDS, patients choose to undergo surgery mainly because of the symptoms caused by lumbar spinal stenosis and are satisfied when most of the symptoms are relieved. Therefore, precision shortsegment fusion can be used to treat most patients with ALDS.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.08.205
ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
In our study, 23 patients with ALDS were treated with precision treatment with the use of selective nerve root block, and good decompression, instrumentation, and fusion with less injury were achieved, in addition to relieving patients’ pain and eventually gaining satisfactory clinical outcome. The VAS scores and ODI decreased immediately after surgery and gradually recovered with time. A significant difference between the postoperative and final follow-up assessments demonstrated this. Therefore, for patients with ALDS, precision treatment may be sufficient for the management of primary symptoms with shorter operative time, much less blood loss, and lower incidence of complications, all of which result in considerably less patient morbidity, less cost, and earlier rehabilitation. ALDS is commonly complicated by coronal and sagittal imbalance, so the deformity correction is an important consideration. However, the corrective course is still controversial. In our study, the mean Cobb angle decreased from 21.6 7.4 to 10.6 6.7 with a mean correction of 11 . Lumbar lordosis changed from 37.1 12.9 to 42.4 10.8 . With a thorough decompression, disc removal, interbody bone graft and cage instrumentation, compression on the convex side, and distraction on the concave side, the local deformity can be corrected to some degree. During surgery, we commonly use a large cage placed on the concave side to restore lumbar lordosis and decrease lumbar curve. The painful stimulus caused by disc herniation or stenosis is removed, and the nerve root, muscle, and ligament are relaxed, which are helpful for deformity correction. As the short fusion does not involve fusion of the whole curve, the outcome of deformity correction is limited. Therefore, long-term outcomes should be studied in the future. Daffner and Vaccaro14 found that degenerative change may progress in the nonfused area in patients undergoing short-segment fusion, which had a higher risk of ASD. To reduce the incidence of ASD, the principles of fixation and fusion are as follows. If 1 or 2 levels are involved, surgery is
REFERENCES 1. Silva FE, Lenke LG. Adult lumbar degenerative scoliosis: evaluation and management. Neurosurg Focus. 2010;28:E1. 2. Cheh G, Bridwell K, Lenke L. Adjacent segment disease following lumbar/thoracolumbar fusion with pedicle screw instrumentation: a minimum 5-year follow-up. Spine (Phila Pa 1976). 2007;32: 53-57. 3. Hong JY, Suh SW, Modi HN, Hur CY, Song HR, Park JH. The prevalence and radiological findings in 1347 elderly patients with scoliosis. J Bone Joint Surg Br. 2010;92:980-983.
performed without considering the location of instrumented vertebra. The human body can share load pressure to each flexible level by self-regulation. When 3 levels are involved, the load pressure is concentrated in the adjacent level, and the fusion should not be stopped at the apex of curvature, the vertebra of spondylolisthesis and lateral subluxation, and the thoracolumbar vertebra in patients with thoracolumbar kyphosis. In our study, only 1 patient had ASD at the final follow-up. However, the followup time in our study was relatively short, and so further research is needed to address this issue. This study has limitations. First, it is a retrospective study, which raises a concern about selection bias and loss to follow-up. Second, patients with ALDS present with many different symptoms, and precision short-segment fusion is not suitable for patients with mechanical low back pain and severe deformity, for which long-segment fusion is needed. Third, the scoliotic angle of patients in our group was relatively small. It is uncertain whether this surgery is suitable for patients with larger scoliotic angles and severe deformity. Finally, the number of cases in our study is relatively small, and the follow-up time is relatively short, so larger case studies with long-term observation should be conducted in the future. CONCLUSIONS For patients with ALDS, we advocate precision short-segment treatment mainly to relieve pain and improve symptoms rather than to correct deformity. There is less blood loss and lower incidence of complications. The nerve root block is an effective and necessary procedure for precision treatment of ALDS. Although we achieved successful results, because of the limited deformity correction, the smaller number of patients, and the shorter follow-up time, further study is required.
7. Cho K, Suk S, Park S, Kim JH, Kang SB. Complications in posterior fusion and instrumentation for degenerative lumbar scoliosis. Spine (Phila Pa 1976). 2007;32:2232-2237. 8. Bridwell KH, Berven S, Edwards C, Glassman S, Hamill C, Schwab F. The problems and limitations of applying evidence-based medicine to primary surgical treatment of adult spinal deformity. Spine (Phila Pa 1976). 2007;32:S135-S139. 9. Kleinstueck FS, Fekete TF, Jeszenszky D, Haschtmann D, Mannion AF. Adult degenerative scoliosis: comparison of patient-rated outcome after three different surgical treatments. Eur Spine J. 2016;25:2649-2656.
5. Crandall D, Morrison M, Baker D. Direct vertebral translation to correct adult scoliosis. Spine J. 2005; 5:118S.
10. Dickerman RD, East JW, Winters K, Tackett J, Hajovsky-Pietla A. Anterior and posterior lumbar interbody fusion with percutaneous pedicle screws: comparison to muscle damage and minimally invasive techniques. Spine (Phila Pa 1976). 2009;34:E923-925.
6. Cho KJ, Suk SI, Park SR, Kim JH, Kang SB, Kim HS, et al. Risk factors of sagittal decompensation after long posterior instrumentation and fusion for degenerative lumbar scoliosis. Spine (Phila Pa 1976). 2010;35:1595-1601.
11. Mummaneni PV, Tu TH, Ziewacz JE, Akinbo OC, Deviren V, Mundis GM. The role of minimally invasive techniques in the treatment of adult spinal deformity. Neurosurg Clin N Am. 2013;24: 231-248.
4. Aebi M. The adult scoliosis. Eur Spine J. 2005;14: 925-948.
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12. Smith WD, Christian G, Serrano S, Malone A comparison of perioperative charges outcome between open and mini-open proaches for anterior lumbar discectomy fusion. J Clin Neurosci. 2012;19:673-680.
KT. and apand
13. Tribus C. Degenerative lumbar scoliosis: evaluation and treatment. J Am Acad Orthop Surg. 2003;11: 174-183. 14. Daffner SD, Vaccaro AR. Adult degenerative lumbar scoliosis. Am J Orthop (Belle Mead, NJ). 2003; 32:77-82. 15. Shufflebarger H, Suk SI, Mardjetko S. Debate: determining the upper instrumented vertebra in the management of adult degenerative scoliosis: stopping at T10 versus L1. Spine (Phila Pa 1976). 2006;31:S185-194. 16. Cho KJ, Suk SI, Park SR, Kim JH, Jung JH. Selection of proximal fusion level for adult degenerative lumbar scoliosis. Eur Spine J. 2013;22: 394-401. 17. Polly DW Jr, Hamill CL, Bridwell KH. Debate: to fuse or not to fuse to the sacrum, the fate of the L5-S1 disc. Spine (Phila Pa 1976). 2006;31:S179-184.
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TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
18. Cho KJ, Suk SI, Park SR, Kim JH, Choi SW, Yoon YH, et al. Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis. Eur Spine J. 2009;18:531-537.
22. Wang MY, Mummaneni PV. Minimally invasive surgery for thoracolumbar spinal deformity: initial clinical experience with clinical and radiographic outcomes. Neurosurg Focus. 2010;28:1-8.
19. Bridwell KH, Edwards CC 2nd, Lenke LG. The pros and cons to saving the L5-S1 motion segment in a long scoliosis fusion construct. Spine (Phila Pa 1976). 2003;28:S234-S242.
23. Schwender JD, Holly LT, Rouben DP, Foley KT. Minimally invasive transforaminal lumbar interbody fusion (TLIF): technical feasibility and initial results. J Spinal Disord Tech. 2005;18:S1-S6.
20. Anand N, Baron EM, Thaiyananthan G, Khalsa K, Goldstein TB. Minimally invasive multilevel percutaneous correction and fusion for adult lumbar degenerative scoliosis: a technique and feasibility study. J Spinal Disord Tech. 2008;21: 459-467. 21. Scheufler KM, Cyron D, Dohmen H, Eckardt A. Less invasive surgical correction of adult degenerative scoliosis, part I: technique and radiographic results. Neurosurgery. 2010;67:696-710.
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24. Hwang DW, Jeon SH, Kim JW, Kim EH, Lee JH, Park KJ. Radiographic progression of degenerative lumbar scoliosis after short segment decompression and fusion. Asian Spine J. 2009;3:58-65. 25. Wang N, Wang D, Wang F, Tan B, Yuan Z. Evaluation of degenerative lumbar scoliosis after short segment decompression and fusion. Medicine. 2015;94:e1824. 26. Anderberg L, Saveland H, Annertz M. Distribution patterns of transforaminal injections in the
cervical spine evaluated by multi-slice computed tomography. Eur Spine J. 2006;15:1465-1471.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 25 June 2018; accepted 27 August 2018 Citation: World Neurosurg. (2018). https://doi.org/10.1016/j.wneu.2018.08.205 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.08.205
Precision Treatment of Adult Lumbar Degenerative Scoliosis Complicated by Lumbar Stenosis with the Use of Selective Nerve Root Block Yan Liang1, Yongfei Zhao2, Tianhao Wang2, Zhenqi Zhu1, Haiying Liu1, Keya Mao2
BACKGROUND: Use of short-segment or long-segment fusion is controversial in treatment of adult lumbar degenerative scoliosis (ALDS). The aim of this study was to explore efficacy and feasibility of precision treatment of ALDS with selective nerve root block.
-
METHODS: From January 2014 to January 2016, a retrospective study of 23 patients with ALDS treated with precision short-segment surgery with at least 2-year follow-up was performed. Fixation segment was determined by selective nerve root block. Visual analog scale and Oswestry Disability Index (ODI) were evaluated preoperatively and at 2-year follow-up. Radiographic measurements included Cobb angle of lumbar curve, lumbar lordosis, sacrum slope, and pelvic tilt. Radiographic evaluation of fusion integrity was performed based on Bridwell interbody fusion grading system at final follow-up.
CONCLUSIONS: Precision treatment of ALDS with selective nerve root block can achieve favorable clinical outcomes and good fusion with less surgical injury and low complications. Deformity correction is limited, which requires further study.
-
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RESULTS: Mean follow-up time was 25.2 1.4 months. Average lumbar curve was 21.6 7.4 preoperatively and 11.2 6.5 at final follow-up (P < 0.01), with correction rate of 48.1%. Lumbar lordosis changed from L37.1 12.9 to L42.1 10.5 at final follow-up (P < 0.01). Mean visual analog scale back pain scores decreased from 6.0 1.8 preoperatively to 1.5 0.8 at final follow-up (P < 0.01), and mean visual analog scale leg pain scores decreased from 8.1 0.6 preoperatively to 1.3 1.3 at final follow-up (P < 0.01). Oswestry Disability Index score improved from 60.9% 15.7% preoperatively to 22.1% 11.6% at final follow-up (P < 0.01). All patients achieved grade I fusion at final evaluation. One patient (4%) needed further surgical intervention.
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Key words - Adult lumbar degenerative scoliosis - Elective nerve root block - Precision treatment Abbreviations and Acronyms ALDS: Adult lumbar degenerative scoliosis ASD: Adjacent segment disease ODI: Oswestry Disability Index VAS: Visual analog scale
INTRODUCTION
A
dult lumbar degenerative scoliosis (ALDS) is defined as a curve >10 resulting from degeneration of the facets and discs.1 The prevalence of ALDS is 8.3%e68%, and the condition is commonly complicated by advanced age, osteoporosis, cardiopulmonary insufficiency, and other medical comorbidities.2,3 The pathophysiology of ALDS involves asymmetric degeneration of disc and facet joints that puts an asymmetric load on the spine, which leads to degenerative scoliosis.4 The clinical symptoms of ALDS are diverse and include back pain, radiating pain to the legs, and deformity.5 The goals of surgery are to relieve back pain, improve radiating pain and claudication, and correct deformity. Clinically, the surgical procedures commonly include decompression alone, decompression and short-segment fusion, and decompression and long-segment fusion with correction of deformity.6,7 However, there are no clear guidelines regarding which surgical procedure yields the best results in different patients.8,9 Thus, surgery should be selected with consideration of the advantages and disadvantages of each surgical option. Long-segment fusion may induce excessive blood loss and prolonged operative time while achieving a good clinical outcome and deformity correction, which will lead to more postoperative complications. The short-segment fusion is selected based on the patient’s medical condition, and several minimally invasive methods of treatment for
From the 1Department of Spinal Surgery, Peking University People’s Hospital; and 2 Orthopedic Department, the PLA General Hospital (301 Hospital), Beijing, China To whom correspondence should be addressed: Keya Mao, M.D.; Haiying Liu, M.D. [E-mail: [email protected]; [email protected]] Yan Liang and Yongfei Zhao are coefirst authors. Citation: World Neurosurg. (2018). https://doi.org/10.1016/j.wneu.2018.08.205 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY -: e1-e6, - 2018
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ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
ALDS have been advocated.10-12 However, limited surgery cannot alleviate the symptoms if performed improperly. The key point is to identify the exact level of fixation and fusion. Therefore, we use a selective nerve root block to determine the course of the surgery. The purpose of this study was to introduce our experiences and explore the efficacy and feasibility of precision treatment of ALDS with the use of selective nerve root block. MATERIALS AND METHODS Patients This study was approved by the institutional review boards of the authors’ affiliated institutions, and all patients gave informed consent to participate in the study. From January 2014 to January 2016, 57 consecutive patients with ALDS who underwent surgery in our hospital were retrospectively analyzed. The clinical presentations of the patients included back pain, intractable unilateral radicular pain, and intermittent claudication. Inclusion criteria were 1) Cobb angle >10 ; 2) posterior-only procedure for adult scoliosis correction; 3) short fusion (limited to 1e3 segments); 4) availability of radiographic examinations (full-length anteroposterior and lateral radiographs) and clinical data (inpatient medical records and questionnaire); and 5) use of nonoperative therapies, including bracing, rest, physiotherapy, and analgesics, without adequate relief of symptoms. Exclusion criteria were 1) idiopathic curves; 2) prior lumbar fusion surgery; and 3) other comorbidities, such as neoplasia, trauma, and infection. Of 57 patients, 23 (40%) were matched with the inclusion criteria (7 men, 16 women; age 63.6 7.4 years). Mean follow-up time was 25.2 1.4 months (range, 24e28 months). Surgical Treatment The fixation and fusion segments were decided by the nerve root block. Before surgery, all patients were treated with nerve root block to confirm the level where the pain originated. If 1 or 2 levels were involved, the surgery was performed without considering the location of the instrumented vertebra. If 3 levels were involved, the fusion was not stopped at the apex of curvature, the vertebra of spondylolisthesis and lateral subluxation, and the thoracolumbar vertebra in patients with thoracolumbar kyphosis. If the 3-level nerve root block was not effective, long-segment fixation and fusion was considered (Figure 1). Data Collection Study measures were obtained through review of inpatient medical records and questionnaires completed by the patients. The primary measures of this study were blood loss, operative time, time to ambulation, postoperative hospital stay, and complications. The complications were categorized as early (within 3 months after surgery) or late postoperative complications.7 Clinical evaluations, which included visual analog scale (VAS) scores for back and leg pain and the Oswestry Disability Index (ODI), were performed preoperatively, postoperatively, and at every follow-up. Preoperative radiologic examination consisted of full-length anteroposterior and lateral radiographs, flexion/extension views, and left and right oblique views. Computed tomography or magnetic resonance imaging was performed to assess the degree and main cause of spinal stenosis and the cause of radiculopathy. Full-length
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anteroposterior and lateral radiographs were obtained postoperatively and at follow-up. Radiographic assessment consisted of Cobb angle of lumbar curve according to the Cobb method (using the maximally angled end vertebra of the coronal curve), lumbar lordosis (L5-S1), sacrum slope, pelvic tilt, and fusion status based on Bridwell interbody fusion grading system, as follows: I, fused with remodeling and trabeculae present; II, graft intact, not fully remodeled and incorporated, but no lucency present; III, graft intact, potential lucency present at top and bottom of graft; IV, fusion absent with collapse and/or resorption of graft. The assessments were performed by 2 independent assessors. Statistical Analysis Data were expressed as mean SD for variables. Preoperative and postoperative differences were calculated using paired t test, and statistical significance was set at P < 0.01. All analyses were carried out using SPSS Version 17 (SPSS, Inc., Chicago, Illinois, USA. RESULTS Surgical Results There were 34 levels treated (mean, 3 segments), including 1 level in 17 patients, which were operated by minimally invasive transforaminal lumbar interbody fusion, and 2 levels in 3 patients and 3 levels in 3 patients, which were operated by open transforaminal lumbar interbody fusion. The primary symptoms were as follows: severe back pain, intractable unilateral radicular pain, and intermittent claudication in 12 patients; mild to moderate back pain, intractable unilateral radicular pain, and intermittent claudication in 8 patients; intractable unilateral radicular pain and intermittent claudication without back pain in 3 patients. The most common level was L4-5 (59%), followed by L3-4 (24%). Transforaminal lumbar interbody fusion and interbody fusion with autogenous bone were performed in all cases. The average operative time was 156.9 26.9 minutes (range, 105e220 minutes) with a mean intraoperative blood loss of 194.6 96.5 mL (range, 75e350 mL). The average hospital stay was 5.7 1.2 days (range, 4e8 days). The average time to ambulation was 2.7 1.0 days (range, 1e4 days) postoperatively. Clinical Results The assessments of VAS pain scores (back and leg) and ODI demonstrated significant clinical differences in preoperatively, postoperatively, and at final follow-up (P < 0.01 and P < 0.01, respectively). A significant difference in the VAS scores or ODI was found between the postoperative and final follow-up assessments (P < 0.01) (Table 1). Radiologic Results The mean Cobb angle decreased from 21.6 7.4 preoperatively to 10.6 6.7 postoperatively with a mean correction of 11 (P < 0.05). The Cobb angle at the final follow-up was 11.2 6.5 , and there was not a statistically significant difference in terms of postoperative and final follow-up results (P > 0.01). For lumbar lordosis, pelvic tilt, and sacrum slope, an obvious difference was found between preoperative and postoperative values (P < 0.01). There was also a significant difference between preoperative and final follow-up values (P < 0.01). No significant differences were observed between
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.08.205
ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
Figure 1. A 53-year-old man with adult lumbar degenerative scoliosis. (AeH) Preoperative x-rays, computed tomography, and magnetic
WORLD NEUROSURGERY -: e1-e6, - 2018
resonance imaging. (I and J) Nerve root block surgery. (K and L) Postoperative x-rays. (M and N) X-rays obtained at 2-year follow-up.
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ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
Table 1. Radiographic and Clinical Outcomes in 23 Patients Variables Cobb,
Preoperative
Postoperative
Final Follow-Up
21.6 7.4
10.6 6.7*
11.2 6.5*y
37.1 12.9
42.4 10.8*
42.1 10.5*y
SS,
27.5 8.4
32.7 7.3*
32.9 6.5*y
PT,
20.7 5.7
15.7 6.8*
15.6 5.9*y
VAS back pain score
6.0 1.8
2.3 0.8*
1.5 0.8*z
VAS leg pain score
8.1 0.6
2.9 0.7*
1.3 1.3*z
60.9 15.7
23.9 8.7*
18.9 7.1*z
LL,
ODI, %
LL, lumbar lordosis; SS, sacrum slope; PT, pelvic tilt; VAS, visual analog scale; ODI, Oswestry Disability Index. *P < 0.01 compared with preoperatively. yP > 0.01 compared with postoperatively. zP < 0.01 compared with postoperatively.
postoperative and final follow-up values (P > 0.01) (Table 1). All patients achieved grade I fusion at the final follow-up according to radiologic evidence. No obvious loss of correction occurred in any of the patients. Complications Early Complications. There were 2 dural tears with cerebrospinal fluid leakage, which were repaired during surgery without other special treatment. One patient had pneumonia and recovered after antibiotic treatment. One patient had fat liquefaction of the incision and recovered after débridement. Late Complications One patient had adjacent segment disease (ASD), which was treated with percutaneous endoscopic discectomy. No complications of neurologic injury or nonunion occurred. No screw or rod breakage or failure occurred. DISCUSSION ALDS is usually caused by degeneration and instability of the spine, and the prevalence and curves increase with age. The symptoms of adult scoliosis are diverse and the relationship between symptoms and deformity is complex, which make surgery challenging. The treatment of ALDS has been controversial.13,14 There are many questions concerning the management of patients with ALDS, and great efforts have been directed toward a more standardized approach to such patients. However, there is no consensus on what is the best choice. The main clinical sign of ALDS is deformity, so many surgeons choose long-segment fusion to correct the deformity. Regarding the choice of the proximal fusion level, Shufflebarger et al.15 suggested that fusion at T10 or higher could prevent ASD because T10 has a true rib that can reinforce the thoracolumbar junction. Cho et al.16 also stated that horizontal or neutral vertebra may help to determine the proximal fusion level, and fusion to T10 is more stable than fusion to T11-L1. Regarding distal fusion, Polly et al.17 stated that fusion to L5 may result in high rates of revision and
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suggested distal fusion to S1.18,19 Long-segment fusion can achieve better deformity correction and global balance. However, an excessive fusion level may result in increased bleeding and a longer operative time, which, together with advanced age of the patient and medical comorbidities, increase the complication rate and the cost of surgery. Moreover, long-segment fusion results in fewer mobile segments and decreased spinal range of motion, which brings many inconveniences to patients. To combat these challenges, short-segment fusion has been developed for treatment of ALDS, which has reduced intraoperative blood loss, lower infection rates, and quicker mobilization.20-23 Hwang et al.24 reported that short-segment fusion achieved a good clinical outcome, and the scoliotic angle does not seriously deteriorate in patients with ALDS. Wang et al.25 found that short-segment fusion resulted in limited correction, with the incidence of ASD not as high as reported previously. With short-segment fusion, correction of deformity is not adequate; however, the goal of surgery is not only to correct deformity but also to minimize complications. When choosing surgical options, surgeons should consider the patient’s general condition in weighing the benefits of surgery and risks of complications. The main goal is to solve the symptom rather than restore the alignment. Therefore, we advocate precision treatment of ALDS. The clinical presentations of patients with ALDS include back pain, radiating pain, neurologic symptoms, and deformity. Although deformity is the primary symptom, low back pain and neurologic symptoms are chief complaints in such patients. Neurologic symptoms caused by spinal stenosis that generally involves a short segment of the spine can be treated by shortsegment decompression and fusion. Low back pain is an important consideration for the choice of surgery strategy. Low back pain in patients with ALDS usually results from 2 pathologic abnormalities. One pathology is caused by degenerative changes in the lumbar disc and facet joint. The protruded disc, dystrophy of the ligament flavum, and other inflammatory tissue stimulate the sinuvertebral nerves, spinal nerve posterolateral branch, and other nerve branches to cause low back pain. The other pathology is mechanical low back pain, which is caused by abnormal spine alignment and muscle fatigue induced by spinal imbalance. Therefore, it is a challenge to distinguish and choose the optimal surgery to treat low back pain in patients with ALDS. Selective nerve root block is a minimally invasive punch block technique for nerve root pain performed under video guidance, which serves as diagnosis and treatment. Anderberg et al.26 reported that 45%e100% of nerve root pain can be diagnosed by nerve root block. Therefore, we applied nerve root block to the treatment of ALDS. In patients with ALDS, the neurologic symptoms and low back pain caused by degenerative changes can be effectively treated by nerve root block. In this way, we not only can identify the responsible level but also can perform precision short-segment fusion in these patients. Although the procedure may not be effective in relieving mechanical low back pain, this symptom is only a small part of the patient’s clinical presentation. Moreover, owing to the complexity of ALDS, patients choose to undergo surgery mainly because of the symptoms caused by lumbar spinal stenosis and are satisfied when most of the symptoms are relieved. Therefore, precision shortsegment fusion can be used to treat most patients with ALDS.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.08.205
ORIGINAL ARTICLE YAN LIANG ET AL.
TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
In our study, 23 patients with ALDS were treated with precision treatment with the use of selective nerve root block, and good decompression, instrumentation, and fusion with less injury were achieved, in addition to relieving patients’ pain and eventually gaining satisfactory clinical outcome. The VAS scores and ODI decreased immediately after surgery and gradually recovered with time. A significant difference between the postoperative and final follow-up assessments demonstrated this. Therefore, for patients with ALDS, precision treatment may be sufficient for the management of primary symptoms with shorter operative time, much less blood loss, and lower incidence of complications, all of which result in considerably less patient morbidity, less cost, and earlier rehabilitation. ALDS is commonly complicated by coronal and sagittal imbalance, so the deformity correction is an important consideration. However, the corrective course is still controversial. In our study, the mean Cobb angle decreased from 21.6 7.4 to 10.6 6.7 with a mean correction of 11 . Lumbar lordosis changed from 37.1 12.9 to 42.4 10.8 . With a thorough decompression, disc removal, interbody bone graft and cage instrumentation, compression on the convex side, and distraction on the concave side, the local deformity can be corrected to some degree. During surgery, we commonly use a large cage placed on the concave side to restore lumbar lordosis and decrease lumbar curve. The painful stimulus caused by disc herniation or stenosis is removed, and the nerve root, muscle, and ligament are relaxed, which are helpful for deformity correction. As the short fusion does not involve fusion of the whole curve, the outcome of deformity correction is limited. Therefore, long-term outcomes should be studied in the future. Daffner and Vaccaro14 found that degenerative change may progress in the nonfused area in patients undergoing short-segment fusion, which had a higher risk of ASD. To reduce the incidence of ASD, the principles of fixation and fusion are as follows. If 1 or 2 levels are involved, surgery is
REFERENCES 1. Silva FE, Lenke LG. Adult lumbar degenerative scoliosis: evaluation and management. Neurosurg Focus. 2010;28:E1. 2. Cheh G, Bridwell K, Lenke L. Adjacent segment disease following lumbar/thoracolumbar fusion with pedicle screw instrumentation: a minimum 5-year follow-up. Spine (Phila Pa 1976). 2007;32: 53-57. 3. Hong JY, Suh SW, Modi HN, Hur CY, Song HR, Park JH. The prevalence and radiological findings in 1347 elderly patients with scoliosis. J Bone Joint Surg Br. 2010;92:980-983.
performed without considering the location of instrumented vertebra. The human body can share load pressure to each flexible level by self-regulation. When 3 levels are involved, the load pressure is concentrated in the adjacent level, and the fusion should not be stopped at the apex of curvature, the vertebra of spondylolisthesis and lateral subluxation, and the thoracolumbar vertebra in patients with thoracolumbar kyphosis. In our study, only 1 patient had ASD at the final follow-up. However, the followup time in our study was relatively short, and so further research is needed to address this issue. This study has limitations. First, it is a retrospective study, which raises a concern about selection bias and loss to follow-up. Second, patients with ALDS present with many different symptoms, and precision short-segment fusion is not suitable for patients with mechanical low back pain and severe deformity, for which long-segment fusion is needed. Third, the scoliotic angle of patients in our group was relatively small. It is uncertain whether this surgery is suitable for patients with larger scoliotic angles and severe deformity. Finally, the number of cases in our study is relatively small, and the follow-up time is relatively short, so larger case studies with long-term observation should be conducted in the future. CONCLUSIONS For patients with ALDS, we advocate precision short-segment treatment mainly to relieve pain and improve symptoms rather than to correct deformity. There is less blood loss and lower incidence of complications. The nerve root block is an effective and necessary procedure for precision treatment of ALDS. Although we achieved successful results, because of the limited deformity correction, the smaller number of patients, and the shorter follow-up time, further study is required.
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TREATMENT OF ALDS WITH SELECTIVE NERVE ROOT BLOCK
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24. Hwang DW, Jeon SH, Kim JW, Kim EH, Lee JH, Park KJ. Radiographic progression of degenerative lumbar scoliosis after short segment decompression and fusion. Asian Spine J. 2009;3:58-65. 25. Wang N, Wang D, Wang F, Tan B, Yuan Z. Evaluation of degenerative lumbar scoliosis after short segment decompression and fusion. Medicine. 2015;94:e1824. 26. Anderberg L, Saveland H, Annertz M. Distribution patterns of transforaminal injections in the
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Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 25 June 2018; accepted 27 August 2018 Citation: World Neurosurg. (2018). https://doi.org/10.1016/j.wneu.2018.08.205 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.08.205