|Year : 2015 | Volume
| Issue : 1 | Page : 133-141
Surgical management of congenital scoliosis
Yasser Hasan El Miligy, Mahmoud Mohamed Hadhoud, Ahmed Ibrahim Zayda, Ashraf Abdel Aziz Abdel Raouf M.B.B, CH
Orthopedic Surgery Department, Faculty of Medicine, Menoufia University, Ezbet el-moallmeen, Faqous, Sharkia, Egypt
|Date of Submission||17-Sep-2014|
|Date of Acceptance||14-Oct-2014|
|Date of Web Publication||29-Apr-2015|
Ashraf Abdel Aziz Abdel Raouf
Orthopedic Surgery Department, Faculty of Medicine, Menoufia University, Ezbet el-moallmeen, Faqous, Sharkia
Source of Support: None, Conflict of Interest: None
The aim of this study was to assess outcomes and complications in patients surgically treated for congenital scoliosis.
Congenital scoliosis due to hemivertebra and unsegmented bar is most often progressive and requires surgical treatment. The recommended surgical options include 'in-situ' fusion, convex hemiepiphysiodesis, and hemivertebra excision.
Patients and methods
This study included 20 patients (six boys and 14 girls). The age at operation was between 4 and 18 years. Two techniques were used: the anterior procedure and the posterior procedure. The anterior procedure involves thoracotomy and the thoracoabdominal approach. In this procedure disc excision above and below the level of the anomaly was performed and the segment of the vertebral column (hemivertebra, segment of unsegmented bar) that would be excised was determined. In the posterior procedure, posterior correction, fixation, decortications, and grafting were performed. Fixation was carried out using claw, sublaminar wires, pedicular screws, and rods.
'In-situ' fusion does not address the anomaly directly; it allows a moderate correction rate but is associated with long spinal fusion. Hemivertebral resection directly addresses the spinal anomaly; it produces the best correction results and is a safe procedure to perform. The average angle after posterior correction and fusion of congenital scoliosis was 37.5 (range from 15 to 60). The percentage of correction was 55% (range from 20 to 90%). The early postoperative correction following the staged combined anterior and posterior correction, and fusion was 60%, ranging from 40 to 80.
The treatment of congenital scoliosis focuses on early diagnosis and appropriate surgical management before the development of large curves. All of the procedures described can be effective and safely performed if correctly selected and performed by an experienced team of surgeons.
Keywords: Congenital scoliosis, hemivertebra, surgical treatment, unsegmented bar
|How to cite this article:|
El Miligy YH, Hadhoud MM, Zayda AI, Raouf AA. Surgical management of congenital scoliosis. Menoufia Med J 2015;28:133-41
| Introduction|| |
Congenital scoliosis is defined as a lateral curvature of the spine due to a developmental abnormality. An incidence of ~1/1000 births has been observed for congenital scoliosis [1-3].
In most cases congenital scoliosis is nonhereditary. Congenital scoliosis is believed to be related to an insult to the fetus during spine embryology development (between the fifth and eighth week of gestation). This is why other malformations such as congenital heart disease, spinal cord dysraphism, or kidney malformations are frequently associated with congenital scoliosis .
Vertebral anomalies causing congenital scoliosis may be caused by failure of formation (wedge vertebra and hemivertebra), failure of segmentation ('enbloc' vertebra and unilateral bars), or by a combination of these two factors, resulting in a mixed deformity. Hemivertebra is the most common cause of congenital scoliosis and may be further classified on the basis of the fusion of the vertebral bodies above and/or below into fully segmented, partially segmented, or unsegmented hemivertebra .
Statistically, 25% of curves are nonprogressive, 25% are mildly progressive, and 50% are highly progressive and will require treatment [6,7].
Treatment for congenital scoliosis may be either observation of the curve, surgery, or, rarely, bracing. Observation is applied only for nonprogressive curves with a balanced spine. Bracing in most instances is totally inefficient in congenital scoliosis. It may be indicated for long flexible curves or to control the compensatory lumbar curve or to help rebalance the spine, or it may be used after an operation, for instance, until the fusion is solid .
Modern treatment options such as expansion thoracoplasty and vertical expander prosthetic titanium rib (VEPTR) - for congenital spine deformities with rib fusions - may be associated with thoracic insufficiency. The surgical concept of expansion thoracoplasty and stabilization with the VEPTR implant is based on the expansion of the thorax by rib distraction on the concave side of the curve, achieving indirect correction of the curve. The best indications are in cases of congenital scoliosis associated with fused ribs and/or in patients with thoracic insufficiency syndrome and/or patients with chest hypoplasia before the age of 8.
The goal of surgery is to achieve a straight spine, a physiological sagittal profile while maintaining flexibility, to arrest progression of the curve, and achieve as short a segment fusion as possible, preserving as much normal spinal growth as possible [9,10].
Preoperative evaluations should include a comprehensive history and physical examination, paying particular attention to the prenatal history, neurological examination, signs of spinal dysraphism, spinal balance, rib cage deformities, and cardiac and renal abnormalities .
Plain radiographs remain standard for the diagnosis of congenital anomalies and for measuring curve magnitude, progression, and growth potential of the vertebral anomaly. CT scans (3D) may help define the anatomy, avoid any unexpected intraoperative posterior element deficiencies, and help in planning the surgical approach. As congenital scoliosis is frequently associated with spinal dysraphism, MRI assumed an important role in preoperative evaluation .
| Patients and methods|| |
Twenty patients with congenital scoliosis (neglected) were included in this study (six boys and 14 girls) and were treated at the student insurance hospital in Cairo from 2013 to 2014, with a follow-up period of 1 year.
Criteria of inclusion
Patients with a preoperative Cobb's angle ranging between 45 and 130° in erect films were included in the study.
Criteria of exclusion
- Patients with preoperative Cobb's angle less than 45° or more than 130° in erect films.
- Patients associated with other anomalies (cardiac, pulmonary, or neurological).
The age at operation was between 4 and 18 years. An overall 60% of the patients were aged 10-14 years; all patients were students. Significant progression of the deformity occurred in 16 patients (80% of the cases), and this was confirmed by serial plain radiograph films of the patients. All patients were followed up regularly for 3 months, and we observed the progression of the curve in the last 6 months of visits. The type of anomaly was unsegmented bar in eight patients and hemivertebra in 12 patients. Cobb's angle ranged between 45 and 130° in erect films preoperatively, with an average of 87.5°. Heights ranged between 75 and 180 cm preoperatively, with an average of 127.5 cm.
Surgical procedures may be broadly divided on the basis of their goal into those preventing further deformity and those that correct the present deformity.
Anesthesia: General anesthesia was used; the hypotensive technique is recommended in all cases of spinal deformity.
Position of the patient: The patient was positioned laterally (the operation involves exposure of the vertebral bodies and the intervertebral discs). In case of congenital scoliosis the patient was positioned with the convex side up. The upper arm was brought forward so that the scapula rotates away from the vertebral column; this enabled the exposure of higher vertebrae if necessary. For accentuation of intervertebral discs, the kidney rest was inserted at the apex of the curve; this allowed easy removal of the disc.
In thoracotomy and the thoracoabdominal approach, adequate exposure requires removal of the proper rib. In general, removal of the fifth rib allows exposure from T5 to T11, and removal of the 10th rib with dissection to the retroperitoneal space can provide access from T10 to the sacrum if needed. Once the chest had been opened, the parietal pleura was incised about 1/2 inch anterior to the head of ribs. The intercostal vessels were then divided between ligature or by cauterization along the same line.
Disc excision was performed above and below the level of the anomaly. The discs were felt as soft, rounded, and protuberant areas of the spine compared with the concave surface of the vertebral body. Disc excision was performed in two stages. At first the discs were removed with nucleus pulpous as completely as possible at each space, using various ronguers and fine-pointed nibbling forceps. In the second step the cartilage endplates were removed as completely as possible using a sharp curette.
The segment of the vertebral column (hemivertebra, segment of unsegmented bar) to be excised was determined. First, we identified the intervertebral foramen of the body to be excised by using a blunt hook or a dissector. Through the intervertebral foramen a kerrison was used to excise the body from the level of the dura, proceeding anteriorly - that is, from the posterior cortex of the body and proceeding anteriorly. After proper exposure of the dura, the rest of hemivertebra was excised safely by using bone nippling forceps and curettes of different sizes. A part of the body and far pedicle can be left at this stage to be excised from the posterior exposure. A chest tube was inserted and all layers were closed separately.
Anesthesia: General anesthesia was used; the hypotensive technique is recommended. A urinary catheter was inserted to monitor the amount of urine output. In addition, the patient was informed before anesthesia about the wake-up test during anesthesia.
Position of the patient: The patient was placed prone on a well-padded scoliosis bridge; care was taken to ensure that the pads were not pressing on the brachial plexus and that the abdomen and genitalia were not compressed. The upper extremities were placed in 90-90 position and pads were placed under the arm, as necessary, to avoid traction on the brachial plexus. The head was turned to the side to avoid possible pressure on the orbit.
A skin incision was made along a line between C7 and the gluteal cleft; the spine was exposed by using electrocautary subperiosteal dissection, followed by complete ligament and capsule removal except at the deeper layer of the ligamentum flavum, at the sites where sublaminar wires were to be placed. The facets were removed except at the sites for hook placement in the lumbar region. The transverse processes were exposed (leaving only its tip) to facilitate pedicular screw insertion and obtain a paraspinal bed for bone grafting.
This was in the form of pedicular screws placed at one or two levels, at the distal end of instrumentation. The first step was to have a clear view of the posterior bony element; the entry site of the pedicle was located at the junction of the superior facet process, the pars interarticularis, and the transverse process. The medullary canal of the pedicle was probed with a graduated pedicle probe. The ball-tipped probe was used to ensure that the canal has a floor and four intact walls. The pedicle path was tapped with a tapper of appropriate size, which was estimated at the time of probing and should be one size smaller than the anticipated screw.
It is important to remember that the orientation and configuration of the vertebrae can be altered in scoliosis and should be considered when placing screws.
This consists of a claw at each side of the most proximal instrumented vertebrae, which is usually T4; each claw consisted of two closed hooks placed facing each other, and the hook sites were prepared with a suitable hook starter and then the hook was inserted. The upper hook is usually a 8.0 mm broad blade hook, which was placed over the transverse process of the selected vertebrae, whereas the lower hook is a 6.5 mm broad blade and was inserted under the inferior facet of the same vertebrae. The level of laminectomy was decided on the basis of the level of the vertebra excised. After wide laminectomy, the facet joints were taken off (with/without the head of the rib). The concave pedicle was then removed to complete vertebral excision performed anteriorly.
These implants were placed between the proximal and distal anchors. They allow the application of different corrective forces on the concave or convex side. They are either hooks or sublaminar wires. Hooks were placed on the concave and convex sides to allow the application of distraction or compression forces on either side, respectively.
This is a very important step in scoliosis surgery to facilitate the formation of an adequate spinal fusion. Decortications with partial removal of the facet were performed before placement of the rod.
The first rod was applied to the convex side, and compression force was loaded to close the posterior triangular osteotomy gap; this procedure corrects scoliotic deformity. The second rod on the concave side was applied with distraction force. Correction is accomplished mainly by using a convex rod, whereas the second rod is used to provide extra stability. The rods were firmly held by the rod holder and gently rotated to maintain sagittal contour until the two hooks compressed against each other to form a claw, and then their set screws were tightened. The sublaminar wires were sequentially tightened from proximal to distal; it is important not to tighten any single wire strongly to avoid cutting through the lamina.
The pedicular screws on the convex side were compressed and the ones on the concave side were distracted. At the end stage, the pedicular screws at either side should be at the same level. The wake-up test was performed and the movement of both lower extremities was performed to ensure that the patient was neurologically intact. It was important to tighten all nuts, set screws, and wires before any further steps were performed. After completion, the rib hump was assessed and, if required, rib resection was performed through the same incision; on an average three to six ribs were removed.
The ribs and any other bone fragments removed were cut in small (match stick) pieces. If not sufficient it was supplemented by posterior iliac crest grafting; the graft was placed in lateral gutter in the lumbar region and midline and laterally in the dorsal region.
Closed suction was placed when needed; the deep fascia was closed tightly, subcutaneous tissue was closed, and skin edges were approximated by subcuticular closure.
The patient was ambulant on the first postoperative day. No external support was used. The patient's height was measured and compared with the preoperative height measurement. The hospital stay was from 5 to 8 days after the second stage. Return to school was after 3 months and his activities gradually restored with time. Light activities such as gentle swimming were allowed after 1.5 months; more activities were allowed after 3 months, and after 6 months all activities were allowed without limitation.
In terms of data collection, we recorded operative time, intraoperative blood loss, and postoperative complications. Postoperative outcome was assessed with the SRS 24 scoring system. Operative time was defined as the time from skin incision to closure. Postoperative complications were categorized as early and late.
There was one patient with chylothorax who was treated with a fat-restricted diet for 20 days, one patient with urinary tract infection, and three patients with wound infection, all of whom were treated with medication.
- Metal failure occurred in two patients, representing 10% of all cases. One patient had a pulled-out claw due to breakage of the sublaminar wire; another patient had pulled out screws due to loosening and they were treated with reattachment.
- There was one patient with pseudarthrosis (representing 5% of all cases) in the middle of the curve with no metal failure repeated; surgery with decortication and grafting was performed.
- Loss of correction occurred only in one patient, representing 5% of all cases; a brace was prescribed and the patient was followed up for 1 year.
- There was one patient with junctional kyphosis, representing 5% of all cases, and this occurred above the level of instrumentation. Repeated surgery was performed by reinsertion of the claw above the level of kyphosis.
| Results|| |
The number of patients operated upon was 20 (six boys and 14 girls; ages ranging 4-18 years). The type of anomaly was unsegmented bar in eight patients and hemivertebra in 12 patients. Cobb's angle ranged between 45 and 130° in erect films preoperatively with an average of 87.5° and between 15 and 60° in the same views postoperatively with an average of 37.5°. Heights ranged between 75-180 cm preoperatively with an average of 127.5 cm and between 78-183 cm postoperatively with an average of 130.5 cm.
The percentage of correction was 55% (range 20-90%). The early postoperative correction following the staged combined anterior and posterior correction and fusion was 60%, ranging from 40 to 80°. At 1 year follow-up, the average loss of correction was 5°, ranging from 3 to 7°.
A total of 14 patients presented with back pain; among them, there was complete relief of pain in 13 patients and only one patient had persistence of preoperative pain.
An overall 98% of patients had a significant cosmetic improvement of Trunkal asymmetry and rib hump.
In the 12th month after instrumentation a lack of bony bridges or trabecular pattern together with a clear intervertebral gap (with associated sclerosis and osteophayt formation) was taken as radiological evidence of nonunion, and implant failure was taken as absolute evidence.
Radiological union was present in 19 patients (95% of patients).
Pseudarthrosis was present in one patient (5%); there was no metal failure at the level of pseudarthrosis.
Pseudarthrosis was painless and loss of correction in this patient was 5° on average. Repeated surgery was performed by decortications of the area of pseudarthrosis with bone grafting (graft taken from iliac crest).
On the basis of the SRS 24 scoring system the results were as follows:
- the score for five patients ranged between 60 and 69%;
- the score for nine patients ranged between 50 and 59%; and
- the score for six patients ranged between 40 and 49%.
[Table 1] illustrates detailed results of treatment of congenital scoliosis (age, sex, cause of deformity, operation performed, and blood loss). [Table 2] illustrates detailed results of treatment of congenital scoliosis (preoperative and postoperative angle of deformity, preoperative and postoperative heights, and early and late complications). [Table 3] illustrates results according to the SRS 24 scoring system. [Table 4] illustrates early complications. [Table 5] illustrates late complications.
|Table 1: Detailed results of treatment of congenital scoliosis (age, sex, cause of deformity, operation performed, and blood|
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|Table 2: Detailed results of treatment of congenital scoliosis (angle of deformity, height, and complications)|
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| Discussion|| |
The goal of posterior surgery is stabilization to prevent further progression rather than correction of the curve.
In this series, the percentage of correction was 55% (range 20-90%). The early postoperative correction following the staged combined anterior and posterior correction and fusion was 60%, ranging from 40 to 80°. Trunkal shift was present in eight patients (40%), all of which were corrected.
Winter et al.  reported 290 patients with congenital scoliosis who had posterior fusion with or without Harrington instrumentation. Correction was limited to 28% in those fused without instrumentation and to 36% in those whom Harrington implants were used. Instrumented distraction across the concavity was associated with the risk of paraplegia. Deformation of the fusion mass because of continued anterior growth was observed in 40 patients (14%), called the crankshaft phenomenon .
In this series, a mean correction of the curve ranged between 42 and 63% in posterior fusion with instrumentation (Isola system).
Hall et al.  reported a mean correction of the curve of 12% in posterior fusion without instrumentation, improving to 35% with Harrington instrumentation.
In this series on hemivertebral excision with posterior instrumentaion, combined anterior and posterior instrumentation with disc excision gave better correction and decreased pseudarthrosis (only one patient had complications from pseudarthrosis and was treated with excision and bone graft) and it prevented the crankshaft phenomenon by removing the growth plates anteriorly. The excision of discs allows greater mobility of the segments and better correction. Bone graft after excision of discs gives better sabilization.
Slabaugh et al.  compared hemivertebral excision with posterior 'in-situ' fusion for lumbosacral hemivertebrae and found better correction of the curve in the group that had excision. Combined anterior and posterior fusion adds the potential benefit of greater correction of the sagittal plane because the excision of discs allows greater mobility of the segments. It also decreases the likelihood of pseudoarthrosis and prevents the crankshaft phenomenon by removing the growth plates anteriorly. As this technique does not address the wedge deformity directly, the entire measured curve must be encompassed in the fusion, including normal segments. Convex epiphysiodesis of the spine was designed to arrest growth while allowing concave growth to correct the deformity. It is necessary to perform convex hemiepiphysiodesis across the entire measured curve, often including a normal segment above and below, to achieve satisfactory improvement. The results of this procedure have been variable and unpredictable .
In this series, hemivertebral excision in four patients was performed. The percentage of correction was 55% (range 51-61%).
Excision of a hemivertebra was first reported in 1928 by Royle in Australia .
Bradford and Boachie-Adjei  reported a mean correction of scoliosis of 68.1% (from 47 to 15°).
In this series, using double rods through posterior fixation yielded a mean correction of 55% (from 42 to 63%).
Lazar and Hall also used a single compression rod in 11 patients through the combined approach. The mean correction of the scoliosis was 70.2% (from 74 to 14°) .
In this series, 20 patients - with unsegmented bar in eight patients and hemivertebra in 12 patients - were studied.The average preoperative major curve angle was 87.5° (ranging from 45 to 130°). Thoracolumbar hemivertebra excision was performed in four patients and anterior discactomy was performed in six patients. Posterior correction was performed with segmental instrumentation (Isola system) in all patients. The average angle after posterior correction and fusion of congenital scoliosis was 37.5° (ranging from 15 to 60°). Complications included two cases of metal failure, one junctional kyphosis, one loss of correction, and persistent pain. Four additional operations had to be performed (one patient had a pulled-out claw due to breakage of sublaminar wire and another patient had pulled out screws due to loosening; they were treated by reattachment. One patient had pseudarthrosis in the middle of the curve with no metal failure. Repeated surgery by decortication and grafting was performed and junctional kyphosis occurred above the level of instrumentation. Repeated surgery was performed by reinsertion of the claw above the level of kyphosis).
Ruf and Harms  reported on 28 cases of posterior-only hemivertebra resection with a mean correction of 71.1% (from 45 to 13°). Complications included two cases of pedicle fracture, three cases of instrumentation failure, two additional operations for curve progression, and one infection. Posterior instrumentation allows an early intervention in very young children. Excellent correction in the frontal and sagittal planes and short segment fusion allows for normal growth in the unaffected parts of the spine .
Shono et al.  and Nakamura et al.  reported similar results with the same technique.
| Conclusion|| |
The best choice of surgical procedure depends on the anomaly itself, the degree of deformity, and experience of the surgical team. The main procedures recommended are as follows: posterior or combined 'in-situ' fusion with instrumentation, hemivertebral excision through a combined approach or posterior-only approach with instrumentation, and anterior discactomy for a disc above an unsegmented bar and for a disc below the level of the unsegmented bar combined with posterior instrumentation.
However, the degree of correction is unpredictable and dependent on the concave growth. Finally, hemivertebral resection is a technique that directly addresses the spinal anomaly and produces the best correction results, and after overcoming the initial problems of neurological injury and instrumentation it is a safe procedure that can be performed in children and even in adults [Figure 1],[Figure 2],[Figure 3],[Figure 4] and [Figure 5].
| Acknowledgements|| |
Conflicts of interest
| References|| |
Giampietro PF, Blank RD, Raggio CL, Merchant S, Jacobsen FS, Faciszewski T, et al
. Congenital and idiopathic scoliosis: clinical and genetic aspects. Clin Med Res 2003; 1
Slabaugh PB, Winter RB, Lonstein JE, Moe JH. Lumbosacral hemivertebrae. A review of twenty-four patients, with excision in eight. Spine (Phila Pa 1976) 1980; 5
Winter RB, Moe, JH, Eilers VE. Congenital scoliosis. A study of 234 patients treated and untreated. Natural history. J Bone Joint Surg Am 1968; 50
McMaster MJ. Spinal growth and congenital deformity of the spine. Spine (Phila Pa 1976) 2006; 31
McMaster MJ, Ohtsuka K. The natural history of congenital scoliosis. A study of two hundred and fifty-one patients. J Bone Joint Surg Am 1982; 64
Winter RB, Moe JH. The results of spinal arthrodesis for congenital spinal deformity in patients younger than five years old. J Bone Joint Surg Am 1982; 64
Winter RB, Moe JH, Lonstein JE. A review of family histories in patients with congenital spine deformities. Orthop Trans 1983; 7:32.
Arlet V, Odent T, Aebi M. Congenital scoliosis. Eur Spine J 2003; 12
Hedequist DJ. Surgical treatment of congenital scoliosis. Orthop Clin North Am 2007; 38
Batra S, Ahuja S. Congenital scoliosis: management and future directions. Acta Orthop Belg 2008; 74
Hall JE, Herdron WA, Levine CR. Surgical treatment of congenital scoliosis with or without Harrington instrumentation. J Bone Joint Surg Am 1981; 63
Holte DC, Winter RB, Lonstein JE, Denis F. Excision of hemivertebrae and wedge resection in the treatment of congenital scoliosis. J Bone Joint Surg Am 1995; 77
Bradford DS, Boachie-Adjei O. One-stage anterior and posterior hemivertebral resection and arthrodesis for congenital scoliosis. J Bone Joint Surg Am 1990; 72
Leatherman KD, Dickson RA. Two-stage corrective surgery for congenital deformities of the spine. J Bone Joint Surg Br 1979; 61-B
Ruf M, Harms J. Hemivertebra resection by a posterior approach: innovative operative technique and first results. Spine (Phila Pa 1976) 2002; 27
Shono Y, Abumi K, Kaneda K. One-stage posterior hemivertebra resection and correction using segmental posterior instrumentation. Spine (Phila Pa 1976) 2001; 26
Nakamura H, Matsuda H, Konishi S, Yamano Y. Single-stage excision of hemivertebrae via the posterior approach alone for congenital spine deformity: follow-up period longer than ten years. Spine (Phila Pa 1976) 2002; 27):110-115.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]