Severe adolescent idiopathic scoliosis: posterior staged correction using a temporary magnetically-controlled growing rod.

PURPOSE: A two-staged posterior correction, using a temporary magnetically controlled growing rod (MCGR), was employed to gradually and safely correct severe adolescent idiopathic scoliosis (AIS). The aim of the study is illustrating the results of this procedure. METHODS: A retrospective review of a consecutive series of 17 severe AIS. The first surgery was a posterior release (multiple Ponte osteotomies) with implant of pedicle screws and MCGR on the concave side of the curve. In post-operative days, a distraction was applied with MCGR, which allowed to obtain a total mean lengthening of 2 cm in about 2 weeks, with no complications arising. In the second posterior surgery, MCGR was removed and the definitive rods were applied for final fusion. The mean pedicle screws density was 93.3% (85-100). The extension of the final posterior fusion-instrumentation was of 13.8 levels (12-15). RESULTS: At an average follow-up (FU) of 2.9 years, the main scoliosis curves from average pre-operative Cobb angle of 98.2° (91°-138°) bent down to 38.3° (35°-76°) after definitive fusion (p < 0.05); at last FU, the overall correction was 58.7% (50.4-71.2), with an average correction loss of 2.1° (1.5°-3.1°). At last FU, no complications were reported. CONCLUSIONS: Gradual traction with MCGR in severe AIS proved to be a safe method to achieve progressive curve correction before posterior final fusion, with no neurologic complications associated to more aggressive one-stage surgeries. In a staged approach, MCGR appears as an alternative to halo traction, avoiding frequent traction-related complications.

Segmental vs non-segmental thoracic pedicle screws constructs in adolescent idiopathic scoliosis: is there any implant alloy effect?

PURPOSE: The aim of this study is to understand how many anchor sites are necessary to obtain maximum posterior correction of idiopathic scoliotic curve and if the alloy of instrumentation, stainless steel or titanium, may have a role in the percent of scoliosis correction. METHODS: We reviewed 143 consecutive patients, affected by AIS (Lenke 1-2), who underwent a posterior spinal fusion with pedicle screw-only instrumentation between 2002 and 2005. According to the implant density and alloy used we divided the cohort in four groups. RESULTS: All 143 patients were reviewed at an average follow-up of 7, 2 years, the overall final main thoracic curve correction averaged 61.4%, whereas the implant density within the major curve averaged 71%. A significant correlation was observed between final% MT correction and preoperative MT flexibility and implant density. CONCLUSIONS: When stainless steel instrumentation is used non-segmental pedicle screw constructs seem to be equally effective as segmental instrumentations in obtaining satisfactory results in patients with main thoracic AIS. When the implant alloy used is titanium one, an implant density of ≥60% should be guaranteed to achieve similar results.

Does hybrid fixation prevent junctional disease after posterior fusion for degenerative lumbar disorders? A minimum 5-year follow-up study.

PURPOSE: Medium- to long-term retrospective evaluation of clinical and radiographic outcome in the treatment of degenerative lumbar diseases with hybrid posterior fixation. METHODS: Thirty patients were included with the mean age of 47.8 years (range 35 to 60 years). All patients underwent posterior lumbar instrumentation using hybrid fixation for lumbar stenosis with instability (13 cases), degenerative spondylolisthesis Meyerding grade I (6 cases), degenerative disc disease of one or more adjacent levels in six cases and mild lumbar degenerative scoliosis in five patients. Clinical outcomes were evaluated using Oswestry disability index (ODI), Roland and Morris disability questionnaire (RMDQ), and the visual analog scale (VAS) pain scores. All patients were assessed by preoperative, postoperative and follow-up standing plain radiographs and lateral X-rays with flexion and extension. Adjacent disc degeneration was also evaluated by magnetic resonance imaging (MRI) at follow-up. RESULTS: At a mean follow-up of 6.1 years, we observed on X-rays and/or MRI 3 cases of adjacent segment disease (10.0 %): two of them (6.6 %) presented symptoms and recurred a new surgery. The last patient (3.3 %) developed asymptomatic retrolisthesis of L3 not requiring revision surgery. The mean preoperative ODI score was 67.6, RMDQ score was 15.1, VAS back pain score was 9.5, and VAS leg pain score was 8.6. Postoperatively, these values improved to 28.1, 5.4, 3.1, and 2.9, respectively, and remained substantially unchanged at the final follow-up: (27.7, 5.2, 2.9, and 2.7, respectively). CONCLUSIONS: After 5-year follow-up, hybrid posterior lumbar fixation presented satisfying clinical outcomes in the treatment of degenerative disease.

Degenerative lumbar scoliosis in elderly patients: dynamic stabilization without fusion versus posterior instrumented fusion.

BACKGROUND CONTEXT: Posterolateral fusion with pedicle screw instrumentation is currently the most widely accepted technique for degenerative lumbar scoliosis in elderly patients. However, a high incidence of complications has been reported in most series. Dynamic stabilization without fusion in patients older than 60 years has not previously been compared with the use of posterior fusion in degenerative lumbar scoliosis. PURPOSE: To compare dynamic stabilization without fusion and posterior instrumented fusion in the treatment of degenerative lumbar scoliosis in elderly patients, in terms of perioperative findings, clinical outcomes, and adverse events. STUDY DESIGN: A retrospective study. PATIENT SAMPLE: Fifty-seven elderly patients were included. There were 45 women (78%) and 12 men (22%) with a mean age of 68.1 years (range, 61-78 years). All patients had degenerative de novo lumbar scoliosis, associated with vertebral canal stenosis in 51 cases (89.4%) and degenerative spondylolisthesis in 24 patients (42.1%). OUTCOME MEASURES: Clinical (Oswestry Disability Index, visual analog scale, Roland-Morris Disability Questionnaire) and radiological (scoliosis and lordosis corrections) outcomes as well as incidence of complications. METHODS: Patients were divided into two groups: 32 patients (dynamic group) had dynamic stabilization without fusion and 25 patients (fusion group) underwent posterior instrumented fusion. All the patients' medical records and X-rays were reviewed. Preoperative, postoperative, and follow-up questionnaires were obtained to evaluate clinical outcomes. RESULTS: At an average follow-up of 64 months (range, 42-90 months), clinical results improved similarly in both groups of patients. Statistically superior scoliosis and final lordosis corrections were achieved with posterior fusion (56.9% vs. 37.3% and -46.8° vs. -35.8°, respectively). However, in the dynamic group, incidence of overall complications was lower (25% vs. 44%), and fewer patients required revision surgery (6.2% vs. 16%). Furthermore, lower average values of operative duration (190 vs. 240 minutes) and blood loss (950 vs. 1,400 cc) were observed in the dynamic group than in the fusion group. CONCLUSIONS: In elderly patients with degenerative lumbar scoliosis, pedicle screw-based dynamic stabilization was less invasive with shorter operative duration, less blood loss, and lower adverse event rates than instrumented posterior fusion. Scoliosis curve reduction and lumbar lordosis were superior after fusion; however, dynamic stabilization achieved satisfying values of both these parameters, and these results were stable after an average follow-up of more than 5 years. Furthermore, there was no difference between the two techniques in terms of functional clinical outcomes at the last follow-up.

Adult's Degenerative Scoliosis: Midterm Results of Dynamic Stabilization without Fusion in Elderly Patients-Is It Effective?

Study Design. A retrospective study. Purpose. Posterolateral fusion with pedicle screw instrumentation used for degenerative lumbar scoliosis can lead to several complications. In elderly patients without sagittal imbalance, dynamic stabilization could represent an option to avoid these adverse events. Methods. 57 patients treated by dynamic stabilization without fusion were included. All patients had degenerative lumbar de novo scoliosis (average Cobb angle 17.2°), without sagittal imbalance, associated in 52 cases (91%) with vertebral canal stenosis and in 24 (42%) with degenerative spondylolisthesis. Nineteen patients (33%) had previously undergone lumbar spinal surgery. Results. At an average followup of 77 months, clinical results improved with statistical significance. Scoliosis Cobb angle was 17.2° (range, 12° to 38°) before surgery and 11.3° (range, 4° to 26°) at last follow-up. In the patients with associated spondylolisthesis, anterior vertebral translation was 19.5% (range, 12% to 27%) before surgery, 16.7% (range, 0% to 25%) after surgery, and 17.5% (range, 0% to 27%) at followup. Complications incidence was low (14%), and few patients required revision surgery (4%). Conclusions. In elderly patients with mild degenerative lumbar scoliosis without sagittal imbalance, pedicle screw-based dynamic stabilization is an effective option, with low complications incidence, granting curve stabilization during time and satisfying clinical results.

Apical vertebral derotation in the posterior treatment of adolescent idiopathic scoliosis: myth or reality?

INTRODUCTION: Direct apical vertebral rotation represents an important goal of posterior surgery for thoracic adolescent idiopathic scoliosis (AIS), so as to obtain a better cosmetic effect and to avoid posterior thoracoplasty. However, the real effectiveness in correction of vertebral rotation, using posterior only procedures, is still open to debate. The aim of the present study is to compare the correction of axial apical rotation obtained with direct rotation procedure versus simple concave rod rotation, in patients treated by posterior fusion for thoracic AIS using pedicle screw-only construct. MATERIALS AND METHODS: A retrospective review was performed on a total of 62 consecutive patients (one single institution, three different surgeons) affected by AIS, who had undergone a posterior spinal fusion with pedicle screw-only instrumentation between January 2005 and April 2008 at the reference center. All cases presented a main thoracic curve (Lenke type 1 and 2). The angle of rotation (RAsag) of the apical vertebra was measured from the preoperative and last follow-up axial CT. According to the derotation procedure, two groups were identified: a direct vertebral rotation group (DR group; n = 32 patients) and a simple concave rod rotation group (No-DR group; n = 30 patients). There were no statistical differences between the two groups, in terms of age, Risser's sign, curve patterns, Cobb main thoracic (MT) curve magnitude and flexibility, extension of fusion, offset measurements on the coronal plane and sagittal preoperative contour. RESULTS: All 62 patients were reviewed at an average follow-up of 3.7 years (range 2.5-4.2 years). The DR group compared to the No-DR group showed a significantly better final correction of apical vertebral rotation (DR 63.4 % vs. No-DR 14.8 %; p < 0.05) and a greater final correction (61.3 vs. 52.4 %; p < 0.05) with better maintenance of the initial correction (-1.7° vs. -1.9°; ns) of the main thoracic curve. Concerning the coronal balance, there was the same aforementioned trend of better results in the DR group, with less final apical MT vertebra translation (DR 2.2 cm vs. No-DR 4.1 cm), greater overall change (preop-final) of lower instrumented vertebra (LIV) coronal tilt (-14.9° vs. -11.1°; p < 0.05); the final global coronal balance (C7-S1) resulted quite better in DR group, but without a significant difference. The T5-T12 kyphosis angle was quite similar in both group before surgery (DR 16.8° vs. No-DR 17.5°) and was little lower at final follow-up evaluation in direct vertebral rotation group (14.5° vs. 16.5°). The T10-L2 sagittal alignment angle was similar in each group before surgery (12.5° in DR vs. 11.8° in No-DR), and at the latest follow-up averaged 5.3° versus 8.2°, respectively. Lumbar lordosis was similar in each group before surgery (DR -42° vs. No-DR -44.1°) and at the final follow-up evaluation (-45.9° vs. -43.2°). At the latest follow-up, SRS-30 and SF-36 findings were similar between the two groups. The complication rate was higher in the simple concave rod rotation group (13.3 vs. 9.3 %), related in two cases to thoracoplasty, which was never utilized in direct rotation patients. CONCLUSIONS: The direct vertebral rotation obtained significantly better final results, when compared to simple concave rod rotation, both concerning correction of apical vertebral rotation and magnitude of MT curve. On the other hand, the DR group presented a little reduction in T5-T12 kyphosis at follow-up, in comparison with concave rod rotation procedure. Both procedures were found to be satisfying from patients' perspective. Nevertheless overall complication rate was higher in the simple concave rod rotation group, related mainly to thoracoplasty (2 cases), which was never necessary in direct rotation patients.

Ex vivo observation of human intervertebral disc tissue and cells isolated from degenerated intervertebral discs.

PURPOSE: Disc degeneration, and associated low back pain, are a primary cause of disability. Disc degeneration is characterized by dysfunctional cells and loss of proteoglycans: since intervertebral tissue has a limited capacity to regenerate, this process is at present considered irreversible. Recently, cell therapy has been suggested to provide more successful treatment of IVD degeneration. To understand the potential of cells to restore IVD structure/function, tissue samples from degenerated IVD versus healthy discs have been compared. METHODS: Discal tissue from 27 patients (40.17 ± 11 years) undergoing surgery for degenerative disc disease (DDD), DDD + herniation and congenital scoliosis, as controls, was investigated. Cells and matrix in the nucleus pulposus (NP) and annulus fibrosus (AF) were characterized by histology. AF- and NP-derived cells were isolated, expanded and characterized for senescence and gene expression. Three-dimensional NP pellets were cultured and stained for glycosaminoglycan formation. RESULTS: Phenotypical markers of degeneration, such as cell clusters, chondrons, and collagen disorganization were seen in the degenerate samples. In severe degeneration, granulation tissue and peripheral vascularization were observed. No correlation was found between the Pfirrmann clinical score and the extent of degeneration. CONCLUSION: The tissue disorganization in degenerate discs and the paucity of cells out of cluster/chondron association, make the IVD-derived cells an unreliable option for disc regeneration.

Late-developing infection following posterior fusion for adolescent idiopathic scoliosis.

This study is a retrospective case series review of patients with adolescent idiopathic scoliosis (AIS) who were revised more than 1 year after the index procedure, due to a late-developing deep wound infection, to determine onset, bacteriology, possible influence of implant alloy (titanium vs. stainless-steel) and treatment outcome of patients. From a total of 540 patients who underwent posterior-only fusion for AIS from 1993 through 2005 at our institution, 15 cases (2.77%) were revised due to a late-developing post-operative infection: there were six males and nine females, with an average age at initial surgery of 15.8 years (range 12-18). Late infections occurred at a mean of 70 months (15-95) after the index procedure. The implant alloy used was a stainless-steel instrumentation in 11 patients (4.56% of 241) and a titanium one in 4 patients (1.33% of 299): there was an higher incidence of late infections in stainless-steel alloy group of patients (P < 0.0001). Complete removal of instrumentation was performed in nine patients, obtaining in all cases wound healing and no symptoms of infection, at a minimum 3 years follow-up. In the other six patients, presenting less severe clinical signs of infections, an attempt to save/replace the previous instrumentation was performed, but a complete instrumentation removal had to be performed 11.6 months later (range 3-24) for the persistence or recurrence of infection: all patients healed uneventfully at a minimum 3 years follow-up. Intraoperative cultures were obtained in all 15 cases, being positive in 13 cases (S. epidermidis in 5 patients, S. aureus in 3, Propionibacterium acnes in 1, Serratia marcescens in 1, Propionibacterium acnes + S. epidermidis in 1, S. aureus + S. epidermidis in 1 and coagulase-negative Staphylococci in 1). None presented at latest follow-up scoliosis progression: there was no statistically significant difference between final and pre-operative revision surgery values (P = 0.17). In conclusion, treatment of late-developing post-operative infection in AIS surgery required complete removal of the implant, continuous drain and adequate antibiotic therapy based on intraoperative swab antibiogram. Titanium alloy instrumentations resulted less subject to late post-operative infections, when compared to stainless-steel ones (P < 0.0001).

Thoracic pedicle subtraction osteotomy in the treatment of severe pediatric deformities.

The traditional surgical treatment of severe spinal deformities, both in adult and pediatric patients, consisted of a 360° approach. Posterior-based spinal osteotomy has recently been reported as a useful and safe technique in maximizing kyphosis and/or kyphoscoliosis correction. It obviates the deleterious effects of an anterior approach and can increase the magnitude of correction both in the coronal and sagittal plane. There are few reports in the literature focusing on the surgical treatment of severe spinal deformities in large pediatric-only series (age <16 years old) by means of a posterior-based spinal osteotomy, with no consistent results on the use of a single posterior-based thoracic pedicle subtraction osteotomy in the treatment of such challenging group of patients. The purpose of the present study was to review our operative experience with pediatric patients undergoing a single level PSO for the correction of thoracic kyphosis/kyphoscoliosis in the region of the spinal cord (T12 and cephalad), and determine the safety and efficacy of posterior thoracic pedicle subtraction osteotomy (PSO) in the treatment of severe pediatric deformities. A retrospective review was performed on 12 consecutive pediatric patients (6 F, 6 M) treated by means of a posterior thoracic PSO between 2002 and 2006 in a single Institution. Average age at surgery was 12.6 years (range, 9-16), whereas the deformity was due to a severe juvenile idiopathic scoliosis in seven cases (average preoperative main thoracic 113°; 90-135); an infantile idiopathic scoliosis in two cases (preoperative main thoracic of 95° and 105°, respectively); a post-laminectomy kypho-scoliosis of 95° (for a intra-medullar ependimoma); an angular kypho-scoliosis due to a spondylo-epiphisary dysplasia (already operated on four times); and a sharp congenital kypho-scoliosis (already operated on by means of a anterior-posterior in situ fusion). In all patients a pedicle screws instrumentation was used, under continuous intra-operative neuromonitoring (SSEP, NMEP, EMG). At an average follow-up of 2.4 years (range, 2-6) the main thoracic curve showed a mean correction of 61°, or a 62.3% (range, 55-70%), with an average thoracic kyphosis of 38.5° (range, 30°-45°), for an overall correction of 65% (range, 60-72%). Mean estimated intra-operative blood loss accounted 19.3 cc/kg (range, 7.7-27.27). In a single case (a post-laminectomy kypho-scoliosis) a complete loss of NMEP occurred, promptly assessed by loosening of the initial correction, with a final negative wake-up test. No permanent neurologic damage, or instrumentation related complications, were observed. According to our experience, posterior-based thoracic pedicle subtraction osteotomies represent a valuable tool in the surgical treatment of severe pediatric spinal deformities, even in revision cases. A dramatic correction of both the coronal and sagittal profile may be achieved. Mandatory the use of a pedicle screws-only instrumentation and a continuous intra-operative neuromonitoring to obviate catastrophic neurologic complications.

Pulmonary function after thoracoplasty in the surgical treatment of adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective case series review. OBJECTIVE: To compare two similar groups of adolescents surgically treated for their spinal deformity either by posterior segmental fusion alone (PSF) or by posterior spinal fusion and thoracoplasty (PSF+T); attention was focused on the long-term effects of thoracoplasty on pulmonary function in the surgical treatment of adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Posterior spinal arthrodesis with thoracoplasty and an open anterior approach, with respect to a posterior only fusion have been found to have a deleterious effect on pulmonary function for as long as five years postoperatively after surgical treatment of adolescent idiopathic scoliosis. METHODS: A group of 40 consecutive adolescent patients, surgically treated between 1998 and 2001 by posterior spinal fusion and thoracoplasty, was compared with a similar cohort of 40 adolescents treated in the same period by posterior segmental fusion alone. Pedicle screw instrumentation alone and a minimum five-year follow-up were requested as inclusion criteria. Both a radiographic analysis and a chart review was performed, evaluating the pulmonary function tests (PFTs), the SRS-30 score questionnaire and the Lenke classification system. A radiographic Rib Hump (RH) assessment was also performed. RESULTS: The entire series was reviewed at an average clinical follow-up of 8.3 years. There were no statistically significant differences between the two groups in terms of gender, age (PSF+T: 16.3 y vs. PSF: 15.2 y), Lenke curve type classification and preoperative Cobb's main thoracic (MT) curve magnitude (PSF+T: 66° vs. PSF: 63°), whereas both final MT percent correction (PSF+T: 53.03% vs. PSF: 51.35%; P<0.03), RH absolute correction (PSF+T: -2.1 cm vs. PSF: -1.05; P<0.01) and RH overall percent correction (PSF+T: 55.4% vs. PSF: 35.4%; P<0.0001) were greater in the thoracoplasty group. No statistical differences were observed between the two groups in PFTs both pre-operatively and at last follow-up. Nevertheless, comparing preoperative to final PFT'S within each group, only in the PSF group both forced vital capacity and forced expiratory volume in one second showed a statistically significant improvement at final evaluation. At last follow-up visit, the SRS-30 scores did not show any statistical difference between the two groups (total score PSF+T: 4.1 vs. PSF: 4.3). CONCLUSIONS: Our findings suggest that thoracoplasty did not adversely affect long-term PFTs in AIS patients treated by posterior spinal fusion alone using pedicle screws instrumentation, as already highlighted by previous reports. A trend towards better coronal plane correction and rib hump improvement was seen, although not clearly reported in a self-assessment disease-specific questionnaire.

Treatment of scoliosis in patients affected with Prader-Willi syndrome using various techniques.

BACKGROUND: The incidence of spinal deformity in children with Prader-Willi syndrome (PWS) is high, with 86% of these patients found to have a significant structural scoliosis; however, there are very few case reports describing surgical treatment for this deformity. METHODS: The authors reviewed a case series consisting of 6 patients who underwent spine surgery for scoliosis. Children's mean age at index surgery was 12 years and 10 months (range, 10 to 15 yrs). Clinical evaluation revealed the typical phenotypic features of the PWS in all of the patients; 4 subjects had a karyotype confirmation of PWS. Major structural curves showed preoperative mean Cobb angles of 80.8 degrees (range, 65 degrees to 96 degrees ). Hybrid instrumentation with sublaminar wires, hooks and screws was used in the first 2 patients, while the remaining 4 were treated with titanium pedicle screw constructs. RESULTS: The mean clinical and radiological follow-up was 3 years and 10 months (range, 2 years to 9 years). Major complication rate was 50%. One patient who developed a major intraoperative complication (paraparesis) prevented spinal fusion to be obtained: the neurologic deficit resolved completely after instrumentation removal. Solid arthrodesis and deformity correction in both coronal and sagittal plane was, however, achieved in the other 5 cases and no significant curve progression was observed at follow-up. Another major short-term complication was encountered 3 months after surgery in a patient who experienced the detachment of a distally located rod and required correction through revision surgery and caudal extension by one level. Cervico-thoracic kyphosis was seen in 1 patient who did not require revision surgery. CONCLUSIONS: Spine reconstructive surgery in patients with PWS is rare and highly demanding.The best method of reconstruction is posterior multilevel pedicle screw fixation. Moreover, even with modern techniques, the risk of complications is still high. These new techniques, however, have shown to improve the postoperative course by allowing for immediate mobilization without any brace or cast. The use of the growing rod techniques, requiring repeated surgeries, should be carefully evaluated in each single case.

Dynamic stabilization for degenerative lumbar scoliosis in elderly patients.

STUDY DESIGN: A retrospective study. OBJECTIVE: To analyze outcomes after dynamic stabilization without fusion in degenerative lumbar scoliosis in elderly patients. SUMMARY OF BACKGROUND DATA: Frequent complications of posterolateral instrumented fusion have been reported after treatment of degenerative lumbar scoliosis in elderly patients. The use of dynamic stabilization without fusion can be advocated to reduce such adverse effects, being less invasive, with shorter operation time and less blood loss. No study in the literature has analyzed outcomes of dynamic stabilization without fusion in these degenerative deformities. METHODS: Twenty-nine elderly patients (average age, 68.5 years; range, 61-78) with degenerative lumbar scoliosis, undergoing dynamic stabilization (Dynesys system) without fusion combined with decompressive laminectomy, in cases with associated stenosis, were analyzed. Stenosis of the vertebral canal was associated in 27 patients (93.1%); 13 cases (44.8%) also presented a degenerative spondylolisthesis. An independent spine surgeon retrospectively reviewed all the patients' medical records and radiographs to assess operative data and surgery-related complications. Preoperative, postoperative, and follow-up questionnaires were obtained to evaluate clinical outcomes. RESULTS: The mean follow-up time was 54 months (range, 39-68). Oswestry Disability Index, Roland Morris Disability Questionnaire, and back pain and leg pain visual analogue scale scores received a statistically significant improvement at last control; the mean improvement was 51.6% for Oswestry Disability Index (P = 0.01), 58.2% for Roland Morris Disability Questionnaire (P = 0.01), 51.7% for leg pain (P = 0.02), and 57.8% for back pain (P = 0.01). Radiographically, degenerative scoliosis and associated spondylolisthesis resulted stable at follow-up with a moderate correction: the average scoliosis Cobb angle was 16.9 degrees (range, 12 degrees -37 degrees) before surgery and 11.1 degrees (range, 4 degrees -26 degrees) at last follow-up, with a 37.5% mean correction (P = 0.01); the anterior vertebral translation was 18.9% (range, 12%-27%) before surgery and 17% (range, 0%-27%) at follow-up, for a 14.6% mean correction (range, 0%-100%) (P = 0.02). No implant-related complications (screw loosening or breakage) or loss of correction were observed. Four cases (13.8%) presented an asymptomatic radiolucent line around screws of the S1 level without screw loosening. Six patients (20.7%) showed minor complications (ileus in 2 cases, urinary tract infection in 2, transient postoperative delirium in one, and respiratory difficulties after surgery in another patient). In 2 other patients (6.8%) incurred major complications, both requiring a revision surgery, for a misplaced screw on L5 and junctional disc degeneration at the lower level respectively. No neurologic complications occurred. CONCLUSION: Dynamic stabilization with pedicle screws in addition to decompressive laminectomy resulted a safe procedure in elderly patients with degenerative lumbar scoliosis; it was able to maintain enough stability to prevent progression of scoliosis and instability, enabling a wide laminectomy in cases of associated lumbar stenosis. This nonfusion stabilization technique was less aggressive than instrumented fusion and obtained a statistically significant improvement of the clinical outcome at last follow-up.

Two-level total lumbar disc replacement.

Total lumbar disc replacement (TDR) has been widely used as a treatment option for 2-level symptomatic degenerative disc disease. However, recent studies have presented conflicting results and some authors concluded that outcome deteriorated when disc replacement was performed bisegmentally, with an increase of complications for bisegmental replacements in comparison with monosegmental disc arthroplasty. The goal of the present retrospective study is to investigate results in a group of patients who have received bisegmental TDR with SB Charitè III artificial disc for degenerative disc disease with a minimum follow-up of 3 years, and to compare the results of 2-level disc replacement versus 1-level patients treated with the same prosthesis. A total of 32 patients had at least 3-years follow-up and were reviewed. The average age of the patients was 38.5 years. There were 11 males and 21 females. About 16 patients received 2-level TDR (SB Charitè III) and 16 received 1-level TDR (SB Charitè III). Both radiographic and functional outcome analysis, including patient's satisfaction, was performed. There were no signs of degenerative changes of the adjacent segments in any case of the 2- or 1-level TDR. There was no statistically significant difference between 2- and 1-level TDR both at 12 months and at 3-years follow-up on functional outcome scores. There was a statistically insignificant difference concerning the patients satisfaction between 1- and 2-level surgeries at the last follow-up (P = 0.46). In the 2-level TDR patients, there were 5 minor complications (31.25%), whereas major complications occurred in 4 more patients (25%) and required a new surgery in 2 cases (12.5%). In the 1-level cases there were 2 minor complications (12.5%) and 2 major complications (12.5%) and a new revision surgery was required in 1 patient (6.25%). In conclusion, the use of 2-level disc replacement at last follow-up presented a higher incidence of complications than in cases with 1-level replacement. At the same time it was impossible to delineate a clear difference in evaluating the questionnaires between the follow-up results of patients receiving 2- and 1-level TDR: the 2-level group presented slightly lower scores at follow-up, but none was statistically significant.

Posterior fusion only for thoracic adolescent idiopathic scoliosis of more than 80 degrees: pedicle screws versus hybrid instrumentation.

The treatment of thoracic adolescent idiopathic scoliosis (AIS) of more than 80 degrees traditionally consisted of a combined procedure, an anterior release performed through an open thoracotomy followed by a posterior fusion. Recently, some studies have reassessed the role of posterior fusion only as treatment for severe thoracic AIS; the correction rate of the thoracic curves was comparable to most series of combined anterior and posterior surgery, with shorter surgery time and without the negative effect on pulmonary function of anterior transthoracic exposure. Compared with other studies published so far on the use of posterior fusion alone for severe thoracic AIS, the present study examines a larger group of patients (52 cases) reviewed at a longer follow-up (average 6.7 years, range 4.5-8.5 years). The aim of the study was to evaluate the clinical and radiographic outcome of surgical treatment for severe thoracic (>80 degrees) AIS treated with posterior spinal fusion alone, and compare comprehensively the results of posterior fusion with a hybrid construct (proximal hooks and distal pedicle screws) versus a pedicle screw instrumentation. All patients (n = 52) with main thoracic AIS curves greater than 80 degrees (Lenke type 1, 2, 3, and 4), surgically treated between 1996 and 2000 at one institution, by posterior spinal fusion either with hybrid instrumentation (PSF-H group; n = 27 patients), or with pedicle screw-only construct (PSF-S group; n = 25 patients) were reviewed. There were no differences between the two groups in terms of age, Risser's sign, Cobb preoperative main thoracic (MT) curve magnitude (PSF-H: 92 degrees vs. PSF-S: 88 degrees), or flexibility on bending films (PSF-H: 27% vs. PSF-S: 25%). Statistical analysis was performed using the t test (paired and unpaired), Wilcoxon test for non-parametric paired analysis, and the Mann-Whitney test for non-parametric unpaired analysis. At the last follow-up, the PSF-S group, when compared to the PSF-H group had a final MT correction rate of 52.4 versus 44.52% (P = 0.001), with a loss of -1.9 degrees versus -11.3 degrees (P = 0.0005), a TL/L correction of 50 versus 43% (ns), a greater correction of the lowest instrumented vertebra translation (-1.00 vs. -0.54 cm; P = 0.04), and tilt (-19 degrees vs. -10 degrees; P = 0.005) on the coronal plane. There were no statistically significant differences in sagittal and global coronal alignment between the two groups (C7-S1 offset: PSF-H = 0.5 cm vs. PSF-S = 0 cm). In the hybrid series (27 patients) surgery-related complications necessitated three revision surgeries, whereas in the screw group (25 patients) one revision surgery was performed. No neurological complications or deep wound infection occurred in this series. In conclusion, posterior spinal fusion for severe thoracic AIS with pedicle screws only, when compared to hybrid construct, allowed a greater coronal correction of both main thoracic and secondary lumbar curves, less loss of the postoperative correction achieved, and fewer revision surgeries. Posterior-only fusion with pedicle screws enabled a good and stable correction of severe scoliosis. However, severe curves may be amenable to hybrid instrumentation that produced analogous results to the screws-only constructs concerning patient satisfaction; at the latest follow-up, SRS-30 and SF-36 scores did not show any statistical differences between the two groups.

Complications of thoracic pedicle screws in scoliosis treatment.

STUDY DESIGN: A retrospective study. OBJECTIVE: To analyze complications with thoracic pedicle screws in scoliosis treatment at our Department over a 3-year period (1999-2001). SUMMARY OF BACKGROUND DATA: The use of pedicle screws remains controversial for thoracic scoliosis for fear of complications. METHODS: A total of 115 consecutive patients who underwent posterior fusion using 1035 transpedicular thoracic screws were reviewed. All patients presented a main thoracic scoliosis with a mean Cobb angle of 75.4 degrees (range, 60 degrees -105 degrees ). For thoracic screw placement, a mini-laminotomy technique was used, inserting a spatula inside the vertebral canal to palpate the borders of the pedicle. Postoperative CT scan was used in 25 patients (21.7%) to study a total of 311 screws, when the screw position was questionable. RESULTS: An independent spine surgeon retrospectively reviewed medical records and radiographs of the patients, at a mean follow-up of 4 years. There were 18 screws misplaced (1.7%) in a total of 13 patients (11.3%). Screw malposition was symptomatic only in 1 patient (pleural effusion and fever) and asymptomatic in the other 12 cases (10.4%). Other complications included intraoperative pedicle fractures in 15 patients (13%), dural tears (without neurologic complications) in 14 cases (12.1%), and superficial wound infections in 2 (1.7%). Another operation for screw removal was performed in 5 patients (4.3%), due to pleural effusion (in 1 case), asymptomatic late lateral loosening of a malpositioned screw (in 1), and the possible future risks related the intrathoracic screw position despite the lack of any symptoms (in 3). Two cases (1.7%) were retreated due to wound infection, without removing instrumentation. There was no loss of correction at follow-up. CONCLUSIONS: The thoracic pedicle screw placement in scoliosis patients requires utmost caution. The mini-laminotomy technique was beneficial in increasing safety of the procedure with an acceptable incidence of complications.

Evidence of a linkage between matrilin-1 gene (MATN1) and idiopathic scoliosis.

BACKGROUND: In a previous study, a number of genes, associated with spine musculoskeletal deformity phenotypes in mouse and in synteny between mouse and man, were identified as candidate genes for IS. Among these genes, MATN1, which carries a polymorphic microsatellite marker within its sequence, was selected for a linkage analysis. MATN1 is localised at 1p35 and is mainly expressed in cartilage. The objective of this study was to assess a linkage disequilibrium between the matrilin-1 (MATN1) gene and the idiopathic scoliosis (IS). METHODS: The genetic study was conducted on a population of 81 trios, each consistent of a daughter/son affected by idiopathic scoliosis (IS) and both parents. In all trios components, the region of MATN1 gene containing the microsatellite marker was amplified by a polymerase chain reaction. The amplicons were analysed by a DNA sequencer-genotyper. The statistical linkage analysis was performed using the extended transmission/disequilibrium test. RESULTS: Three microsatellite polymorphisms, respectively consisting of 103 bp, 101 bp and 99 bp, were identified. ETDT evidenced a significant preferential transmission for the 103 bp allele (Chi-square = 5.058, df = 1, P = 0.024) CONCLUSION: The results suggest that the familial idiopathic scoliosis is associated to the MATN1 gene.

Surgical treatment for scoliosis in Marfan syndrome.

STUDY DESIGN: Review of results of patients with Marfan syndrome treated with instrumented posterior fusion alone for scoliosis. OBJECTIVE: To analyze the results of surgical treatment for scoliosis in Marfan syndrome. SUMMARY OF BACKGROUND DATA: Few studies have been reported in the literature on surgical treatment for scoliosis in Marfan syndrome, analyzing long-term results of posterior instrumented fusion. METHODS: Twenty-three patients with Marfan syndrome with a mean age of 17 years (range, 11-31 years) were treated surgically from 1982 to 1995 for scoliosis, using a posterior instrumented fusion alone (Harrington rod with sublaminar wires in the first 16 cases, and a more recent hybrid instrumentation in the remaining 7 cases). All of the patients received a long posterior instrumented fusion, including 12.3 levels on average (range, 9-17), extending the fusion area to vertebrae that were neutral and stable in both coronal and sagittal planes before surgery. Patients were analyzed as two different groups (Group 1 and Group 2) according to the different posterior instrumentations employed: Group 1 included 16 patients treated by the Harrington distraction rod technique with sublaminar wires, while Group 2 included 7 patients treated using more recent hybrid instrumentations. Presentation features, complications, and results were analyzed. RESULTS: At a minimum follow-up of 7 years (maximum, 18 years), all 23 patients were reviewed. The mean age was 26.8 years (range, 20-38 years). The average preoperative scoliosis value of 69.91 degrees was initially corrected to 38.17 degrees, averaged 40.89 degrees 1 year after surgery, and was finally equal to 44.09 degrees at the last follow-up. Differences in terms of scoliosis correction achieved with different instrumentations (Groups 1 and 2) did not reach statistical significance. In Group 2 patients, the percentage of postoperative correction was slightly lower (44.23%) than that of Group 1 (46.55%) but remained more stable at the last follow-up (40.97% vs. 36.38% of Group 1). There were 11 complications in 10 of the 23 patients (43.4%); two complications occurred in 1 patient. Intraoperatively, dural tears occurred in 2 cases (8.6%). Pseudarthrosis with instrumentation failure in 2 cases (8.6%) required revision surgery. Five (21.7%) distal hook dislodgements with moderate loss of scoliosis correction, 1 (4.3%) mild loss of correction without instrumentation failure, and 1 asymptomatic cervicothoracic junctional kyphosis. did not require surgery. All complications occurred among the 16 Group 1 patients, treated using the Harrington rod instrumentation with sublaminar wires. CONCLUSIONS: These results seemed to demonstrate that a satisfactory stabilization of scoliosis can be achieved by posterior instrumentation alone in patients with Marfan syndrome. Instrumented posterior fusion should be extended to include vertebrae that are neutral and stable in both coronal and sagittal planes before surgery, in order to ensure stabilization of the deformity and reduce the risks of decompensation of the spine.

C1-C2 posterior fusion in growing patients: long-term follow-up.

STUDY DESIGN: A retrospective review of patients undergoing C1-C2 posterior fusion during childhood was undertaken. OBJECTIVES: The aim of this study was to investigate the change in the sagittal curvature of the cervical spine in children after C1-C2 posterior fusion. SUMMARY OF BACKGROUND DATA: There have been only a few reports on postoperative changes in the sagittal curvature of the cervical spine after C1-C2 posterior fusion in children. However, they have all described the onset of sagittal postoperative cervical deformities. METHODS: Between January 1977 and December 1992, a total of 12 children underwent C1-C2 posterior fusion for atlantoaxial instability resulting from congenital malformation in eight, juvenile rheumatoid arthritis in one, and rotatory subluxation in three. The average age at the time of surgery was 10.9 years (range 7-12 years). All children underwent a similar treatment program with gradual preoperative reduction in halo cast, followed by C1-C2 posterior fusion with Mersilene loops in two cases, wiring in eight (Gallie's or Brooks' techniques), and interlaminar clamps in the remaining two. The halo cast made it possible to avoid a hyperextended or hyperflexed C1-C2 position while performing the atlantoaxial fusion, thus ensuring a more anatomic position during C1-C2 fusion. In the postoperative period, the halo cast was maintained for 7 to 9 weeks. RESULTS Follow-up ranged from 7 years to 13 years. Preoperative alignment of the cervical spine was classified into two groups: lordosis (eight patients) and straight (four patients). Postoperative subaxial malalignment (kyphosis) occurred in four cases (33%): these patients showed evidence of spontaneous and gradual sagittal improvement and presented either a straight (two cases) or a lordotic (two cases) cervical spine at follow-up. Immediately after surgery, the cervical spine was normally aligned in the remaining eight patients (lordosis and straight alignment in six and two cases, respectively) and was unchanged at follow-up. At follow-up, none of the 12 patients had a cervical deformity on sagittal plane. CONCLUSION: In children, a spontaneous realignment of the subaxial kyphosis observed after C1-C2 posterior fusion can be noted at follow-up, when a postoperative deformity occurs (33% in the present series). According to the present findings, it is not always mandatory to perform occipitocervical fusion in children with atlantoaxial instability just to prevent subaxial deformity in the cervical spine.

Treatment of spinal fractures in children and adolescents: long-term results in 44 patients.

STUDY DESIGN: The authors examined a case series of patients younger than 16 years who had sustained a traumatic spine injury. OBJECTIVES: To evaluate clinical and radiologic findings and the effectiveness of conservative versus surgical treatment at long-term follow-up. SUMMARY OF BACKGROUND DATA: Although injuries to children have received increasing coverage in the literature over the last several years, few reports have focused on the long-term results of conservative versus surgical treatment. METHODS: Forty-four patients who had sustained a traumatic spine injury at the average age of 14 years (range 3-16 years) were clinically and radiographically reviewed. The fractures were separated into three groups: stable (n = 20) and unstable (n = 13) injuries without cord lesion and fractures with spinal cord lesion (n = 11). Mean follow-up was 18 years (range 9-23 years). RESULTS: Conservative treatment was successful in all stable fractures, whereas it failed in the unstable injuries. The surgical treatment stabilized without significant deformity in five of the seven unstable fractures. Of 11 with spinal cord injuries, the 4 children conservatively treated developed a severely progressive, paralytic scoliosis. Only three of the seven surgically treated patients were stabilized without any deformity at follow-up. CONCLUSION: In children and adolescents, conservative treatment is an available option for stable fractures without neurologic lesion. Early surgical treatment (instrumentation and fusion) is mandatory for unstable fractures and injuries associated with spinal cord lesion. In children, a traumatic spinal cord lesion may develop a deformity that is mainly scoliotic, kyphotic, or lordotic in >90% of the cases.