Journal List > J Korean Neurosurg Soc > v.58(1) > 1161776

Hyun, Kim, Park, Kim, Jahng, and Kim: Adolescent Idiopathic Scoliosis Treatment by a Korean Neurosurgeon: The Changing Role for Neurosurgeons

Abstract

Objective

The purpose of this study was to evaluate radiographic/clinical outcomes of adolescent idiopathic scoliosis (AIS) patients treated by a Korean neurosurgeon.

Methods

Ten AIS patients were treated by a single neurosurgeon between January 2011 and September 2013 utilizing segmental instrumentation with pedicle screws. Basic demographic information, curve pattern by Lenke classification, number of levels treated, amount of correction achieved, radiographic/clinical outcomes [by Scolisis Resarch Society (SRS-22r) questionnaire] and complications were evaluated to determine the surgical results. Pulmonary function test was utilized to assess forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) before and after surgery.

Results

The average percentage of correction of the major structural curve was 73.6% (ranged from 64% to 81.5%). Preoperative and final postoperative absolute FVC averaged 3.03 L and 3.76 L (0.73 L increase, p=0.046), and absolute FEV1 averaged 2.63 L and 3.49 L (0.86 L increase, p=0.021). Preoperative and final postoperative average self-image and function scores of SRS-22r were, 2.6±0.5, 3.3±0.1, 4.0±0.5, and 4.6±0.0, respectively. There was a significant improvement of the self-image and function scores of SRS-22r questionnaires before and after surgery (p<0.05). There was no case of neurological deficit, infection and revision for screw malposition. One patient underwent a fusion extension surgery for shoulder asymmetry.

Conclusion

Radiographic/clinical outcomes of AIS patients treated by a Korean neurosurgeon were acceptable. Fundamental understanding of pediatric spinal deformity is essential for the practice of AIS surgery.

INTRODUCTION

A categorized disease of spinal deformities, adolescent idiopathic scoliosis (AIS) takes majority of pediatric spinal deformities. Various impacts of the spinal deformity include progression of the deformity, neurological aggravation, cardiopulmonary and psychosocial problems. Since the department of neurosurgery was established in Republic of Korea, the treatment of spinal deformity has not been discussed enough compared to other spinal disorders. However, neurosurgeons have expanded their interests in complex spinal deformities including pediatric spinal deformity such as congenital and adolescent scoliosis4). By high-level technical ability of the spinal cord handling to preserve neurological function, better synergistic effect could be expected. Nevertheless, thorough understanding of pediatric spinal deformity disorders, biology and biomechanics of bone, and metallurgy is absolutely needed. The purpose of this study was to evaluate radiographic and clinical outcomes of AIS patients treated by a Korean neurosurgeon at a single academic center.

MATERIALS AND METHODS

Patients population and the index surgeon

Ten patients who were treated with AIS at our institution between January 2011 and September 2013 were enrolled. The majority were females (7 patients) with average age of 15.3 vs. 15.8. Mean follow-up period was 18.9 month (4-35 months). The index surgeon had been trained by two senior members of scoliosis research society (SRS). One senior mentor was a neurosurgeon and the other's an orthopedic surgeon. He had an oversea instruction by Lenke9) (SRS past-president) for one year. As a neurosurgeon, he has studied orthopedic surgical discipline for spinal deformity surgery.

Pre-and postoperative evaluation

To keep the humerus from blocking visualization of the spine with adequate balance, 36-inch whole spine plain radiographs were checked with fists on clavicle position2). To protect the kids, any radiographs were taken with gonad shield. Spinal curves pattern were classified by Lenke classification and clinical photo including forward bending view of the all patients were taken before and after surgery to compare their clinical gross feature7). Scolisis Resarch Society (SRS-22r) questionnaire was surveyed regularly (preoperative, postoperative six week, one year, two year and so forth) and pulmonary function was examined to assess forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) before and after surgery (one- and two-year after surgery). Number of fusion levels, amount of curve collection by comparison of standing whole spine plain radiographs, surgical complications, radiologic and clinical outcomes were evaluated at every visit to outpatients clinic.

Operative methods

Under general anesthesia, all patients were flipped to prone position on the Jackson spine table. Intraoperative somatosensory evoked potential and trans-cranial motor evoked potential monitoring were set up. Without an any radiographic guidance, all pedicle screws were inserted by freehand technique for segmental instrumentation3568). After screw placement, various correction maneuvers including translation technique, rod derotation, and direct vertebral rotation were utilized for deformity correction. Then, balance of the shoulders and junctional discs was evaluated by portable whole spine radiographs. Sequentially abundant posterior bone graft was performed using local bone with or without allograft bone chips.

RESULTS

Radiographic results

The average number of fusion levels of female and male patients was 10.4 and 12 vertebral bodies, respectively. The range of Cobb angle at structural major curvature was 51-75 degrees. The average percentage of correction of the major structural curve was 73.6% (ranged from 64% to 81.5%) (Fig. 1).

Pulmonary function test

Preoperative and final postoperative absolute FVC averaged 3.03 L and 3.76 L, respectively (0.73 L increase, p=0.046). Preoperative and final postoperative absolute FEV1 averaged 2.63 L and 3.49 L, respectively (0.86 L increase, p=0.021).

Clinical outcomes and complications

Preoperative and final postoperative average self-image and function scores of SRS-22r were, 2.6±0.5, 3.3±0.1, 4.0±0.5, and 4.6±0.0, respectively. Based on the data, significant improvement of the self-image and function scores of SRS-22r questionnaires were achieved through surgery (p<0.05) (Fig. 2). No cases of neurological deficit, infection or screw malposition arose. One patient, however, underwent a revision fusion extension surgery for shoulder asymmetry.

DISCUSSION

Adolescent idiopathic scoliosis typically develops in females around the time of menarche and presents with a conspicuous back or chest-wall deformity. Cosmetic purposes are the most common motivators behind surgery, nevertheless neurological function is normal and symptoms are minimal. Traditionally, orthopedic surgeons have played an important role in the treatment of AIS. This might be attributable to the orthopedic surgeons' experience with osseous fixation for long-bone and skeletal fractures. However, neurosurgeons have recognized that a fundamental understanding of spinal deformity is essential for neurological surgery. For sure, there were several anecdotal cases of AIS diagnosis and treatment by Korean neurosurgeons410). Since Korean Spinal Deformity Society has taught Korean neurosurgeons fundamental knowledge of spinal deformity, AIS patients treated by neurosurgeons have increased rapidly.

Classification from King and Moe to Lenke

Adolescent idiopathic scoliosis is first classified by King and Moe at 1983 based on the experience with Harrington rod instrumentation18). To simplify the curve patterns, curves were divided into five types. But, as segmental instrumentation systems began to gain favor by spine surgeons, new classification system which was presented by Lenke in 20019). Lenke classification achieved popularity because of its higher inter- and intra-reliability compared to the King and Moe classification. Although the Lenke classification is more comprehensive and reliable than the King classification, there are still several rule breakers such as 'C' lumbar modifier11).

Surgical indication and timing

A general indication of AIS corrective surgery is as follows : scoliosis exceeding 40° or continued and documented progression of the curvature refractory to brace therapy17). However, health insurance review and assessment service of Republic of Korea permits 15-year-old and older patients having over 50° curvature to undergo corrective surgery. That is the reason why the range of Cobb angle at structural major curvature was 51-75° in this study. Curvature measuring greater than 70° is likely to be associated with cardiopulmonary or neurological symptoms, even after skeletal maturity, making these deficits are more difficult to correct in advanced stages of disease11618). In cases of mild scoliosis, brace therapy can be used to delay or even prevent the need for surgery. Often times, surgery is delayed until maximum possible skeletal maturity has occurred. Skeletal maturity is determined by plain radiograph appearance of the iliac apophysis, commonly known as the Risser sign, usually reached at age 14 years in females and age 18 years in males131718).

Selection of the level to fuse

If surgical treatment is decided, radiographic analysis is essential to confirm the upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV). Standing posteroanterior whole spine radiograph including the cervical spine and both hip joints is mandatory. Side bending view is helpful to determine whether a curve is structural or non-structural. After identifying the curve type by Lenke classification9) (curve pattern 1-6 according to major or minor curves, lumbar modifier A-C, sagittal profile hypo-/normo-/hyper-kyphosis), translation and rotation of the apical vertebra is assessed. General rule for selecting the level to fuse is to include the major curve and any structural minor curves. Regarding the approach, anteriorly versus posteriorly, and the actual UIV and LIV are selected by shoulder position and curve type12).

Peri-operative complications and managements

The SRS has been collecting mortality and morbidity database from its members since its foundation in 1965 to assess the complications and adverse outcomes of surgical treatment for spinal deformity. By SRS database, complications were reported in 5.7% of the 6334 patients 1415). The complications include deep wound infection, pseudarthrosis, neurologic problem, blindness and death. The incidence of surgical complications is not too high, patient and family members expected excellent surgical results because AIS is rarely symptomatic. Peri-operative management is not different with adult spinal deformity, however, external orthosis is not necessarily used owing to good bone quality and modern fixation system.

SRS-22r instrument

After surgery, comparing the results between pre-and postoperative condition is also important. SRS-22r questionnaire results and cardio-pulmonary function tests can be used to evaluate the effectiveness of treatment in terms of functional symptoms, pain, self-image improvement and satisfaction with the operative management. As an evaluation tool for patient's outcome, SRS-questionnaire instrument has been revised from SRS-24 to SRS-22. Nowadays, SRS-22r is widely used. The function, pain, self-image, and mental health domains consisted of five questions and the satisfaction with management domain consisted of two214).
Traditionally, orthopedic surgeons are the primary providers of treatment for spinal deformity. Their work has provided major contributions to understanding the biomechanical factors behind spinal correction. However, by treating a subset of spinal deformity patients, neurosurgeons have been making parallel advances in the understanding of spinal disorders6). Regardless of small population, this study shows that the AIS surgery can be performed by a Korean neurosurgeon with acceptable outcomes. However, a fundamental understanding of pediatric spinal deformity and growing spine is essential for the practice of AIS surgery. We recommend any neurosurgeons who want to treat AIS to undergo their training for better knowledge and enhance their surgical skills through our 'Korean Spinal Deformity Society'.

CONCLUSION

Radiographic and clinical outcomes of AIS treatment by a Korean neurosurgeon shows acceptable results. With a fundamental knowledge of pediatric spinal deformity and growing spine, Korean neurosurgeons could play a major role on AIS treatment including corrective surgeries.

References

1. Ascani E, Bartolozzi P, Logroscino CA, Marchetti PG, Ponte A, Savini R, et al. Natural history of untreated idiopathic scoliosis after skeletal maturity. Spine (Phila Pa 1976). 1986; 11:784–789. PMID: 3810293.
crossref
2. Asher MA, Min Lai S, Burton DC. Further development and validation of the Scoliosis Research Society (SRS) outcomes instrument. Spine (Phila Pa 1976). 2000; 25:2381–2386. PMID: 10984792.
crossref
3. Faro FD, Marks MC, Pawelek J, Newton PO. Evaluation of a functional position for lateral radiograph acquisition in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2004; 29:2284–2289. PMID: 15480143.
crossref
4. Han IH, Chin DK, Kim KS. Short segment anterior correction of adolescent idiopathic scoliosis. J Korean Neurosurg Soc. 2008; 44:52–56. PMID: 19096658.
crossref
5. Hyun SJ, Kim YJ, Cheh G, Yoon SH, Rhim SC. Free hand pedicle screw placement in the thoracic spine without any radiographic guidance : technical note, a cadaveric study. J Korean Neurosurg Soc. 2012; 51:66–70. PMID: 22396849.
crossref
6. Johnson JP, Pashman RS, Lauryssen C, Anand N, Regan JJ, Bray RS. The changing role for neurosurgeons and the treatment of spinal deformity. J Neurosurg Spine. 2005; 2:233–242. PMID: 15796346.
crossref
7. Kim YJ, Lenke LG, Bridwell KH, Cho YS, Riew KD. Free hand pedicle screw placement in the thoracic spine : is it safe? Spine (Phila Pa 1976). 2004; 29:333–342. discussion 342PMID: 14752359.
8. Lee CH, Hyun SJ, Kim YJ, Kim KJ, Jahng TA, Kim HJ. Accuracy of free hand pedicle screw installation in the thoracic and lumbar spine by a young surgeon : an analysis of the first consecutive 306 screws using computed tomography. Asian Spine J. 2014; 8:237–243. PMID: 24967036.
crossref
9. Lenke LG, Betz RR, Harms J, Bridwell KH, Clements DH, Lowe TG, et al. Adolescent idiopathic scoliosis : a new classification to determine extent of spinal arthrodesis. J Bone Joint Surg Am. 2001; 83-A:1169–1181. PMID: 11507125.
10. Oh CH, Shim YS, Yoon SH, Park HC, Park CO, Lee MS. The psychopathological influence of adolescent idiopathic scoliosis in Korean male : an analysis of multiphasic personal inventory test results. J Korean Neurosurg Soc. 2013; 53:13–18. PMID: 23440382.
crossref
11. Ovadia D. Classification of adolescent idiopathic scoliosis (AIS). J Child Orthop. 2013; 7:25–28. PMID: 24432055.
crossref
12. Panchmatia JR, Isaac A, Muthukumar T, Gibson AJ, Lehovsky J. The 10 key steps for radiographic analysis of adolescent idiopathic scoliosis. Clin Radiol. 2015; 70:235–242. PMID: 25600209.
crossref
13. Risser JC, Norquist DM, Cockrell BR Jr, Tateiwa M, Hoppenfeld S. The effect of posterior spine fusion on the growing spine. Clin Orthop Relat Res. 1966; 46:127–139. PMID: 5915107.
14. Schlösser TP, Stadhouder A, Schimmel JJ, Lehr AM, van der Heijden GJ, Castelein RM. Reliability and validity of the adapted Dutch version of the revised Scoliosis Research Society 22-item questionnaire. Spine J. 2014; 14:1663–1672. PMID: 24360746.
crossref
15. Weinstein SL, Dolan LA, Cheng JC, Danielsson A, Morcuende JA. Adolescent idiopathic scoliosis. Lancet. 2008; 371:1527–1537. PMID: 18456103.
crossref
16. Weinstein SL, Ponseti IV. Curve progression in idiopathic scoliosis. J Bone Joint Surg Am. 1983; 65:447–455. PMID: 6833318.
crossref
17. Wiggins GC, Shaffrey CI, Abel MF, Menezes AH. Pediatric spinal deformities. Neurosurg Focus. 2003; 14:e3. PMID: 15766220.
crossref
18. Winter RB, Leonard AS. Surgical correction of congenital thoracic lordosis. J Pediatr Orthop. 1990; 10:805–808. PMID: 2250071.
crossref
Fig. 1

A and B : Preoperative whole spine plain radiograph showing scoliotic curvature with 60 degree Lenke 1BN type. C and D : Postoperative 6 months whole spine plain radiograph demonstrating a balanced spine after surgical correction.

jkns-58-50-g001
Fig. 2

A and B : Clinical photographs showing scoliosis and prominent rib hump on the right side at Adam's forward bending test. C and D : Postoperative 6 month clinical photographs demonstrating reduced rib hump after surgical correction.

jkns-58-50-g002
TOOLS
Similar articles