Cotrel-Dubousset (CD) or Universal Spine System (USS) instrumentation in adolescent idiopathic scoliosis (AIS): comparison of midterm clinical, functional, and radiologic outcomes

Defining "successful" treatment outcomes in adolescent idiopathic scoliosis: a scoping review

PURPOSE

Adolescent idiopathic scoliosis (AIS) is the most common type of scoliosis that affects children aged 10-18 years old, manifesting in a three-dimensional spinal deformity. This study aimed to explore outcome measures used in defining AIS treatment success. Particularly, analyzing the extent of qualitative and quantitative (radiographic and quality of life domains) measures to evaluate AIS and whether AIS treatment approaches (surgical, bracing and physiotherapy) influences outcomes used as proxies of treatment success.

METHODS

EMBASE and MEDLINE databases were used to conduct a systematic scoping review with 654 search queries. 158 papers met the inclusion criteria and were screened for data extraction. Extractable variables included: study characteristics, study participant characteristics, type of study, type of intervention approach and outcome measures.

RESULTS

All 158 studies measured quantitative outcomes. 61.38% of papers used radiographic outcomes whilst 38.62% of papers used quantitative quality of life outcomes to evaluate treatment success. Irrespective of treatment intervention utilized, the type of quantitative outcome measure recorded were similar in proportion. Moreover, of the radiographic outcome measures, the subcategory Cobb angle was predominantly used across all intervention approaches. For quantitative quality of life measures, questionnaires investigating multiple domains such as SRS were primarily used as proxies of AIS treatment success across all intervention approaches.

CONCLUSION

This study identified that no articles employed qualitative measures of describing the psychosocial implications of AIS in defining treatment success. Although quantitative measures have merit in clinical diagnoses and management, there is increasing value in using qualitative methods such as thematic analysis in guiding clinicians to develop a biopsychosocial approach for patient care.

Safety and Efficacy of Stand-Alone Bioactive Glass Injectable Putty or Granules in Posterior Vertebral Fusion for Adolescent Idiopathic and Non-Idiopathic Scoliosis

Posterior spinal fusion (PSF) is the standard procedure for the treatment of severe scoliosis. PSF is a standard procedure that combines posterior instrumentation with bone grafting and/or bone substitutes to enhance fusion. The aim of this retrospective study was to evaluate and compare the post-operative safety and efficiency of stand-alone bioactive glass putty and granules in posterior spine fusion for scoliosis in a paediatric cohort. A total of 43 children and adolescents were included retrospectively. Each patient's last follow-up was performed at 24 months and included clinical and radiological evaluations. Pseudarthrosis was defined as a loss of correction measuring >10° of Cobb angle between the pre-operative and last follow-up measurements. There was no significant loss of correction between the immediate post-operative timepoint and the 24-month follow-up. There was no sign of non-union, implant displacement or rod breakage. Bioactive glass in the form of putty or granules is an easily handled biomaterial but still a newcomer on the market. This study shows that the massive use of bioactive glass in posterior fusion, when combined with proper surgical planning, hardware placement and correction, is effective in providing good clinical and radiological outcomes.

Long-Term Health-Related Quality of Life After Harrington Instrumentation and Fusion for Adolescent Idiopathic Scoliosis: A Minimum 40-Year Follow-up

BACKGROUND

Despite its importance for clinical decisions, the long-term consequences of posterior spinal instrumentation and fusion (PSIF) for adolescent idiopathic scoliosis (AIS), particularly in the lower lumbar spine, remain unclear. This study evaluates the long-term health-related quality of life and the need for a further surgical procedure in patients treated with Harrington instrumentation from 1961 to 1977 according to the lowest instrumented vertebra (LIV) and in comparison with age-matched norms.

METHODS

A search was performed to identify and contact the 314 identified patients with AIS treated with PSIF by Dr. L.A. Goldstein. The assessment included identified subsequent spine surgery, the Oswestry Disability Index (ODI), Scoliosis Research Society-7 (SRS-7), EuroQol-5 Dimensions (EQ-5D), and Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29). The health-related quality of life was compared with U.S. norms and, within the cohort, was compared by patient factors, LIV, and subsequent spine surgery.

RESULTS

In this study, 134 patients (42.7%) were identified; 24 (7.6%) had died, 81 (25.8%) consented to participate in the study, and 29 (9.2%) declined participation. The mean follow-up was 45.4 years (range, 40 to 56 years). There were 81 patients who completed the surveys, 77 patients who completed the SRS-7, 77 patients who completed the ODI, and 76 patients who completed the PROMIS-29 and EQ-5D. There were 12.8% of patients with LIV L3 or proximal and 36.4% with LIV L4 or distal who had an additional surgical procedure (odds ratio, 3.98). Comparing the ODI of patients who had undergone an additional surgical procedure with those who had not showed 42% and 73% minimal disability, 53% and 23% moderate disability, and 5% and 2% severe disability. Of the patients who had not undergone an additional surgical procedure, those with LIV L3 or proximal had mean scores of 14.12 points for the ODI and 23.3 points for the SRS-7 and those with LIV L4 or distal had mean scores of 17.9 points for the ODI and 22.7 points for the SRS-7; these differences were not significant. The mean PROMIS-29 and EQ-5D scores were not different from normal U.S. age-based means.

CONCLUSIONS

Patients with AIS treated with PSIF at a mean 45-year follow-up and LIV L4 or distal had a higher rate of undergoing an additional surgical procedure than those with LIV L3 or proximal. Patients undergoing an additional surgical procedure had lower health-related quality of life than those who did not. Despite this, there was no difference in health-related quality of life for patients with LIV L4 or distal compared with patients with LIV L3 or proximal. This cohort of patients with AIS treated with PSIF demonstrates normal self-reported health-related quality of life compared with the age-matched general population. These long-term outcomes of PSIF for AIS are encouraging.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Recognition of posterior thoracolumbar instrumentations used in spinal deformity surgery and techniques for implant removal

Spinal surgeries requiring implant removals/revisions are becoming more common, as a long time has passed since contemporary spinal instrumentation was developed and utilized. Recognizing implants and manufacturers preoperatively from radiographs and preparing appropriate instruments for removal are mandatory. The objective of the present paper was to review the various designs of contemporary posterior thoracolumbar spinal implants along with their radiographic features to facilitate the identification of previously used systems in removal or revision surgeries. We focused on contemporary spinal implants that have been commonly used in spinal deformity surgery since the development of screw-and-rod constructs up to 2005. The pertinent information was requested from three major manufacturers (DePuy Synthes, Medtronic and Stryker). Characteristics of each system are reviewed with radiographic features, and the instruments needed for revision are summarized. We propose a systematic identification diagram. Rod loading can be categorized as offset-loading, side-loading or top-loading. Screw design can be cylindrical, conical or dual-core threading. Each system has unique features that can facilitate identification. Identifying the materials and diameters of the rod is also imperative. When removal of an unidentified system is needed or removal of an identified system fails, the short rod has to remain loaded on the screw and the implant removed en bloc as an isolated piece. Understanding the radiographic features of spinal implants used in previous surgeries will help surgeons prepare for the increasing incidence of revision surgeries.

A systematic scoping review and textual narrative synthesis of long-term health-related quality of life outcomes for adolescent idiopathic scoliosis

INTRODUCTION

Idiopathic scoliosis is a musculoskeletal condition leading to deformity of the spinal column. There is strong evidence reporting short term health-related quality of life outcomes, but less is known about the longer-term impact of adolescent idiopathic scoliosis (AIS). This paper reports the current evidence on long-term non-clinical outcomes of AIS.

METHOD

A systematic scoping literature review combining descriptive and textual narrative synthesis was undertaken. Studies were included if they: sampled or followed up participants at least 10 years after diagnosis and/or treatment, contained health-related quality of life data that could be extracted, where the intervention (or diagnosis in the case of untreated) occurred after 1980, and where data was extractable for modern rod and screw or fusion techniques, non-surgical interventions or untreated patients.

RESULTS

Twenty-three studies were included. Overall, the HRQOL measures utilised by these studies suggest that HRQOL is not related to participant demographics or AIS characteristics or type or extent of surgical intervention. Some studies suggest that those with AIS scored worse than controls.

DISCUSSION

Results suggest that AIS participants had a generally good quality of life, although this was often worse than those without AIS. No other clear relationships were found. The available literature fails to address more fundamental questions about how HRQOL is conceptualised for those with AIS, and there is value in pursuing qualitative inquiry in this area.

Effects of pre-contoured and in situ contoured rods on the mechanical strength and durability of posterior cervical instrumentation: a finite-element analysis and scanning electron microscopy investigation

STUDY DESIGN

Finite-element analysis.

OBJECTIVES

Intraoperative contouring of rods is a common procedure for spine surgeons to match the native curvature of the spine, but it may lead to premature weakening of the rod. This study investigated the effect of different bending methods on rod fatigue performance. Rod failure in the cervical spine is of clinical concern, particularly when spanning the cervicothoracic region and when considering corrective osteotomies for deformity correction and global spinal alignment.

METHODS

Finite-element models were developed to simulate rod bending (3.5 mm D, 40 mm L) to achieve a 23° angle with 3 different bending methods: French single, multiple bending, and in situ bending. Simulations were conducted in 4 steps: rod bending, rod spring back, residual stress relaxation, and F1717 mechanical test simulation.

RESULTS

French single bending resulted in the highest residual stress concentrations for both titanium (TiAlV) and cobalt chrome (CoCr) at 783 MPa and 507 MPa, respectively. During F1717 test simulation, the French single bent rod had its highest tensile stress in the middle, with 917 MPa and 623 MPa, respectively, for TiAlV and CoCr, compared to in situ (580 MPa and 586 MPa for TiAlV and CoCr) and the French multiple bent rod (765 MPa and 619 MPa for TiAlV and CoCr). The computational model found that CoCr rods made the construct least prone to deformation.

CONCLUSIONS

French single bend with TiAlV rods put the construct at highest risk of failure. CoCr rods led to minimal physical changes in microstructure while showing evidence of flattening.

Patient-reported Outcomes Following Surgical Intervention for Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-Analysis

STUDY DESIGN

This was a systematic review and meta-analysis.

OBJECTIVE

This study aims to perform a systematic review and quantitative meta-analysis of patient-reported outcome measures after spinal fusion for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Radiographic correction of scoliosis is extensively reported in the literature but there is a need to study the impact of spinal fusion on patient-reported outcome measures. Prior reviews lacked homogeneity in outcome measures, did not perform quantitative meta-analysis of pooled effect size, or interpret the results in light of minimally clinically important difference thresholds.

MATERIALS AND METHODS

A systematic review of medical databases identified all studies that prospectively reported Scoliosis Research Society (SRS)-22 questionnaire data after spinal fusion for AIS. We screened 2314 studies for eligibility. Studies were included that reported preoperative and postoperative data at 24- or >60-month follow-up. Studies were excluded that failed to report means and SDs which were needed to calculate Cohen d effect sizes and 95% confidence intervals in estimating the magnitude and precision of the effect.

RESULTS

A total of 7 studies met eligibility criteria for inclusion in quantitative meta-analysis of effect sizes and 95% confidence intervals. Patients report large improvements in total score, self-image, and satisfaction; and moderate improvements in pain, function and mental health at 2 and 5 years after spinal fusion for AIS. All domains showed statistically significant improvement at all times except function at >60 months. All domains surpassed the minimally clinically important difference at all times except mental health.

CONCLUSIONS

Moderate evidence suggests that spinal fusion improves quality of life for adolescents with idiopathic scoliosis in medium and long-term follow-up. Our results may help inform patient expectations regarding surgery.

OCEMB LEVEL OF EVIDENCE

Level I-systematic review and meta-analysis of prospective studies.

Hybrid constructs pedicle screw with apical sublaminar bands versus pedicle screws only for surgical correction of adolescent idiopathic scoliosis

PURPOSE

To compare the 2-year minimum postoperative results of posterior correction and spinal arthrodesis using translational correction with hybrid (sublaminar bands on concave side and pedicle screw) constructs versus correction with intermediate density pedicle screw-only constructs in the treatment of AIS (Lenke 1).

METHODS

A total of 37 patients with AIS at single institutions who underwent posterior spinal arthrodesis pedicle screw with sublaminar bands at the apex (19 patients) (Group A) or pedicle screw-only (18) constructs (Group B) were selected and matched according to similar age at surgery 13.8 years (Group A) and 14.3 years (Group B), similar arthrodesis area 12.3 (Group A) and 11.5 (Group B), all curves Lenke type 1 with similar pre-op curve 54° (Group A) and 57° (Group B). Patients were evaluated pre-op, immediately post-op, and at min 2-year follow-up according to radiographic curve correction, operating time, intraoperative blood loss, and f.u. loss of correction.

RESULTS

The average curve correction was 65.6% in sublaminar group and 68% in pedicle screw group. At 2-year follow-up, loss of the major curve correction was 2% in sublaminar group compared to 3% in pedicle screw group. Postoperative coronal and sagittal balance was similar in both groups. Operating time averaged 200 min (Group A) and 180 min (Group B). Intraoperative blood loss was significantly different in both groups 700 ± 160 cc in sublaminar group and 630 ± 150 cc in pedicle screw group. There were no neurologic complications in both groups.

CONCLUSION

The two groups offer similar curve correction without neurologic complications in the surgical treatment of AIS (Lenke 1). The use of sublaminar bands on the apex (concave side) can be a valid fixation in the presence of hypoplastic pedicle, can reduce the thoracic hypokyphosis and derotate the vertebra but had more blood loss comparing to pedicle screws alone. These slides can be retrieved under Electronic Supplementary Material.

Is Convex Derotation Equally Effective as Concave Derotation for Achieving Adequate Correction of Selective Lenke's Type- 1 Scoliosis?

BACKGROUND

Correcting the scoliosis and stabilizing the spine in the corrected position is the basis of treatment for adolescent idiopathic scoliosis (AIS). Spinal instrumentation and derotation are the principle steps of surgery for any type of AIS. A perspicuous understanding needs to be attained regarding derotation maneuvers in practice; therefore, we intend to compare radiological outcomes following concave and convex rod derotation maneuvers to analyze their efficacy to correct selective Lenke's Type-1 scoliosis.

MATERIALS AND METHODS

Retrospectively, 88 patients with Lenke's Type-1 scoliosis who were operated with selective thoracic instrumentation were divided into two groups depending on the derotation side. Preoperative radiographs were analyzed for curve angles, thoracic apical vertebral translation, apical vertebral rotation, and coronal/sagittal balance. Postoperative and followup assessment was focused on curve correction. Correction rate of main thoracic (MT) curve and its corresponding loss of correction at final followup are calculated.

RESULTS

Concave group (n = 40; age 13.8 ± 1.9) and the convex group (n = 48; Age 14.3 ± 2.4) showed similar demographic characteristics. Postoperative and followup parameters showed no significant difference. Correction rate of MT curve between both groups (concave group = 69.2 ± 10.5%; convex group = 66 ± 12.8%; P = 0.20) was similar. There was minimal loss of correction at final followup among both groups (concave group = 2.2° ±5.4°; Convex group = 1.5° ± 4.8°; P = 0.52).

CONCLUSION

The study results showed similar sustained satisfactory correction of flexible Lenke's type 1 scoliotic curves irrespective of the derotation maneuver used. Adequate correction, thereby restoring balance was predominantly perceived among the entire sample. Hence, convex derotation can be considered equally effective as that of concave derotation for achieving adequate correction of selective Lenke's Type-1 scoliosis.

SRS-22r Scores in Nonoperated Adolescent Idiopathic Scoliosis Patients With Curves Greater Than Forty Degrees

STUDY DESIGN

Case control comparative series.

OBJECTIVE

Describe surgical range adolescent idiopathic scoliosis (AIS) patients electing to forgo surgery and compare health-related quality-of-life outcomes to a similar cohort of operated AIS patients by the same single surgeon.

SUMMARY OF BACKGROUND DATA

No data have been published either documenting SRS-22r scores of nonoperated patients with curves ≥40° or comparing these scores to a demographically similar operated cohort.

METHODS

Individuals with curves ≥40°, age ≥18 years, and electing to forgo surgery were identified. All patients completed an SRS-22r questionnaire. This nonoperated cohort's SRS-22r scores were compared to those of a large demographically similar cohort operated by the same surgeon. Group differences between the SRS-22r scores were evaluated by comparing these to published Minimal Clinically Important Differences (MCID) for the SRS-22r.

RESULTS

One hundred ninety subjects with nonoperated curves were compared to 166 individuals who underwent surgery. The nonoperated cohort averaged 23.5 years of age, averaged 7.7 years since curve reached 40°, and had an average 50° Cobb angle at last follow-up. No statistical significant differences were found between the groups on the Pain, Function, or Mental Health domains of the SRS-22r. Statistically significant differences in favor of the operative cohort were found for self-image, satisfaction, and total score. The observed group differences did not meet the established thresholds for minimal clinically important differences in any of the domain scores, the average total score, or raw scores.

CONCLUSION

There are no meaningful clinically significant differences in SRS-22r scores at average 8-year follow-up between AIS patients with curves ≥40° treated with or without surgery. These data in conjunction with an absence of long-term evidence of serious medical consequences with nonsurgical management of curves ≥40° should encourage surgeons to reevaluate the benefits of routine surgical care.

LEVEL OF EVIDENCE

3.

A randomized double-blinded clinical trial to evaluate the safety and efficacy of a novel superelastic nickel-titanium spinal rod in adolescent idiopathic scoliosis: 5-year follow-up

PURPOSE

To evaluate the safety and efficacy of a superelastic shape-memory alloy (SNT) rod used in the treatment of adolescent idiopathic scoliosis (AIS).

METHODS

AIS Patients with Lenke 1 curves undergoing fusion surgery were randomized (1:1) at the time of surgery to receive either the SNT or a conventional titanium alloy (CTA) rod. Radiographs were obtained preoperatively and postoperatively up to 5 years of follow-up. Parameters assessed included coronal and sagittal Cobb angles, and overall truncal and shoulder balance. Sagittal profiles were subcategorized into Types A (<20°), B (20-40°), and C (>40°).

RESULTS

Twenty-four patients with mean age of 15 years were recruited. A total of 87.0% of subjects were followed up till postoperative 5 years, but all patients had minimum 2 years of follow-up. The fulcrum-bending correction index for the SNT group was 113% at postoperative day 4 and 127% at half-year, while the CTA group was 112% at postoperative day 4 and only 106% at half-year. In terms of sagittal profile, the SNT group moved toward type B profile at half-year follow-up with a mean correction of 7.6°, while no significant change was observed in the CTA group (-0.7°). Nickel levels remained normal, and there were no complications.

CONCLUSIONS

This is the first randomized clinical trial of a novel SNT rod for treating patients with AIS, noting it to be safe and has potential to gradually correct scoliosis over time. This study serves as a pilot and platform to properly power future large-scale studies to demonstrate efficacy and superiority.

Hemoptysis Due to Anterior Scoliosis Implants: A Case Report

CASE

A twenty-five-year-old man presented with recurrent episodes of hemoptysis requiring hospitalization and interventional embolization. Instrumentation that had been implanted ten years previously for anterior spinal correction and fusion to treat adolescent idiopathic scoliosis adjoined the medial border of the right lung. The instrumentation eroded the lung during respiration, which prompted the formation of adhesions and fibrosis. Because of the risk of additional hemoptysis events, we performed revision thoracotomy, removal of the spinal instrumentation, and partial lobectomy.

CONCLUSION

This rare and serious complication underscores the importance of meticulous surgical technique to ensure proper implant placement and of vigilant monitoring for late iatrogenic injury.

Reckoning: Assessment of a 21-year activity in spine surgery

Introduction: Of the world-wide used Cotrel–Dubousset instrumentation and surgical technique providing breakthrough for the three-dimensional correction and multi-segmental fixation of spinal deformity surgery in Hungary is linked to the author’s name, who carried out 1655 spine deformity surgeries in the last 21 years. Aim: The aim of the author was to discuss his own results in the field of spine surgery and compare his own data to those published in the international literature. Method: At the beginning hooks, followed by hybrid instrumentation with hooks in thoracic area and transpedicular screws in lumbar spine have been used for the segmental fixation. During the correction process, initially the classic derotation maneuver was used, followed by the translation and then the in situ bending techniques and, finally, a combination of the above three techniques have been applied. Results: In addition to the restoration of normal sagittal balance, an average of 40.8° (SD, 25.9), a 65.5% correction was achieved in the frontal plane, which partly exceeds and partly consistent with the published international results. The incidence of inflammation (3.9%), and mechanical complications (1.7%) was similar to the international average, while the incidence of neurological complications (0.48%) was slightly lower than the average of international data. Conclusions: The author believes that the better correction results as compared to the international average could be due to the always consistent application of the Cotrel–Dubousset instrumentation correction philosophy based on the meticulous segmental analysis of spine deformities. Orv. Hetil., 2015, 156(15), 598–607.

Selection of the Lowest Level for Fusion in Adolescent Idiopathic Scoliosis-A Systematic Review and Meta-Analysis

STUDY DESIGN

A systematic review of studies reporting pain as a long-term outcome after spinal fusion surgery for treatment of adolescent idiopathic scoliosis.

OBJECTIVE

To identify studies that report pain after spinal fusion surgery for scoliosis based on the distal extent of fusion and to combine results to determine if there is an increased incidence of back pain in patients treated with fusion to the lower lumbar spine.

SUMMARY OF BACKGROUND DATA

The methods and results of existing studies are inconsistent and only occasionally reach statistical significance. No thorough review of the available information has been published.

METHODS

An electronic literature search was performed to identify studies that met predetermined eligibility criteria. Data extracted included number of cases fused to L3 or above, to L4 or L5, and the number of those cases experiencing pain. Further, when possible, the pain variable was stratified into severe or mild categories to allow a more specific subanalysis.

RESULTS

Eight studies met inclusion criteria. The meta-analysis for occurrence of pain, the primary outcome, resulted in a final odds ratio of 1.29 (95% CI 0.91-1.82, n = 1,155). When pain was stratified according to severity and only those cases in the severe category considered for meta-analysis, the resulting odds ratio was 1.43 (95% CI 0.72-2.82, n = 900). Neither analysis reached statistical significance.

CONCLUSIONS

Although there was a trend toward increased pain in patients whose fusion extended to L4 or L5, there was no statistically significant association between the distal level of fusion and incidence of subsequent back pain, both with and without stratification according to severity of back pain. Because of the limitations of published research, the effect of fusion into the lower lumbar spine on back pain is unknown. Higher quality studies with long-term follow-up and consistent reporting of outcomes are needed.

Adolescent idiopathic scoliosis correction achieved by posteromedial translation using polyester bands: A comparative study of subtransverse process versus sublaminar fixation

PURPOSE

Sublaminar polyester bands have been used in hybrid construct to achieve correction of adolescent idiopathic scoliosis since 2003. Despite the reported safety of the bands, some surgeons remain reluctant at the idea of approaching the canal because of the potential neurological complications reported with the Luque wiring. Sub transverse bands might be an alternative. The present study is the first to compare sublaminar polyester band fixation to fixation of polyester bands around the transverse processes in hybrid constructs used to treat AIS.

METHODS

Two cohorts of consecutive patients treated for thoracic AIS were retrospectively reviewed, with a minimum 2-year follow-up. Posteromedial translation was used for main curve correction in all cases. Sublaminar polyester bands were used in group 1 (20 patients). In group 2 (20 patients), the same implant was used, but the bands were passed around the transverse process instead of the lamina. Radiographic analysis included frontal Cobb angle measurements for each curve, thoracic kyphosis and rotation of the apical vertebra (RVA).

RESULTS

Mean operative time was similar in groups 1 and 2 (235±35 and 240±30minutes, respectively). Mean frontal correction achieved for the main curve was similar in both groups, 62.5±17.4% in group 1 and 54.1±19.4% in group 2. Sagittal correction was similar, with a final mean thoracic kyphosis of 30.9°±9.7° and 27.8°± 6.8° in group 1 and 2, respectively. Correction of RVA was similar in both groups postoperatively, 65.8% (±29.1) and 54.4% (±42.7) in group 1 and 2 respectively. No transverse process or lamina fracture was observed during insertion of the bands or curve correction in any of the groups.

CONCLUSION

This study confirms that anchorage of Universal clamps (UCs) around transverse processes is a safe and efficacious technique in both the frontal and sagittal planes, providing a useful alternative for the correction of moderate AIS. UCs attached to transverse processes can achieve correction of moderate AIS similar to that obtained with sublaminar UCs while further reducing risks of vertebral canal complications.

LEVEL OF EVIDENCE

Level IV.

Does the size of the rod affect the surgical results in adolescent idiopathic scoliosis? 5.5-mm versus 6.35-mm rod

BACKGROUND CONTEXT

Favorable clinical outcomes of surgical treatment with Cotrel-Dubousset instrumentation (CDI) or instrumentations that follow the principles of CDI, for adolescent idiopathic scoliosis (AIS) have been reported. However, there are few studies concerning the results with rods of different sizes.

PURPOSE

To find out whether the rod size affects the surgical results for AIS.

STUDY DESIGN

A retrospective cohort study based on the same spinal system with different sizes of rod.

PATIENT SAMPLE

A consecutive series of 93 patients, who underwent posterior correction with posterior instrumentation and fusion for AIS, were included and retrospectively analyzed.

OUTCOME MEASURES

Postoperative radiologic outcomes were evaluated using coronal curves, percentage of curve correction, and coronal global balance.

METHODS

Ninety-three patients treated during the period January 2000 to December 2008 were included in this study; 48 patients were treated with the Cotrel-Dubousset Horizon (CDH) M10 system with a 6.35-mm rod from January 2000 through December 2004, and a CDH M8 was used with a 5.5-mm rod in another 45 patients from January 2005 through December 2008. The Cobb angle, Risser grade, coronal curves, flexibility of curve, percentage of curve correction, coronal global balance, operative time, and estimated blood loss were measured and analyzed. The same parameters were used when the patient was followed at the OPD. All of the patients underwent regular follow-up for at least 2 years.

RESULTS

No statistical significance was observed in the demographic data, including age, sex, BMI, and Risser grade, between these 2 groups. The overall average percentage of correction was 60.0%±12.7%: 60.7%±12.5% for the CDH M10 group, and 59%±13.1% for the CDH M8 group. At the final follow-up, the overall average loss of correction was 4.8±3.9° for the CDH M10 group, and 4.3±4.0° for the CDH M8 group. The average percentage of correction at the final follow-up was 50.9%±15.1% for the CDH M10 group, and 51.1%±16.1% for the M8 group. No statistical significance could be observed in the radiologic parameters between these 2 groups.

CONCLUSION

The radiologic results for the 5.5-mm rod and the 6.35-mm rod were comparable in terms of correction, loss of correction, and coronal global balance.

The Universal Clamp hybrid system: a safe technique to correct deformity and restore kyphosis in adolescent idiopathic scoliosis

PURPOSE

Adolescent idiopathic scoliosis (AIS) is a tridimensional deformity characterized by coronal and sagittal profiles changes. We present a series of 62 patients affected by AIS and treated by thoracic Universal Clamps and transpedicular lumbar screws hybrid system.

METHODS

Mean age was 13 years. Average pre-operative Cobb angle was 63° ± 12°. Patients were divided into two groups depending on the kyphosis angle: lower than 45° (51 patients, 82.3 %, mean 21° ± 3°) and higher than 45° (11 patients, 17.7 %, mean 62° ± 6°).

RESULTS

The average percentage of coronal correction was 70 ± 3 % (mean post-operative Cobb angle 19° ± 4°, P < 0.001). In patients with pre-operative physiological thoracic kyphosis-hypokyphosis, we observed an increase in the average value (32° ± 4°, P < 0.001), while in patients with pre-operative hyperkyphosis, mean decrease of thoracic kyphosis was 19° ± 3° (43° ± 4°, P < 0.001).

CONCLUSIONS

This case-series study showed the efficacy and safety of Universal Clamp hybrid system in correcting coronal deformity and restoring physiological thoracic kyphosis in patients affected by AIS.

Role of the upper and lowest instrumented vertebrae in predicting the postoperative coronal balance in Lenke 5C patients after selective posterior fusion

PURPOSE

To investigate which pre- and postoperative radiographic parameters are significantly correlated with the immediate postoperative coronal balance (CB) in Lenke 5C AIS patients, and to identify any radiographic parameter that is correlated with the ultimate CB at a minimum follow-up of 2 years.

METHODS

Forty Lenke 5C AIS patients were recruited in the current study. Preoperative, immediate postoperative, and the latest follow-up radiographs were reviewed measuring various radiographic parameters related to UIV and LIV. The correlations between different parameters and CB were then studied.

RESULTS

The average follow-up time was 35.2 months. Correlation analysis showed that the following radiographic parameters significantly associated with the immediate postoperative CB in Lenke 5C patients: preoperative CB (r = 0.66, p < 0.01), preoperative UIV translation (r = 0.61, p < 0.01), preoperative LIV tilt (r = 0.61, p < 0.01), postoperative UIV translation (r = 0.51, p < 0.05), and postoperative LIV tilt (r = 0.50, p < 0.05). At the last follow-up, only the final UIV tilt was inversely correlated with the ultimate CB (r = -0.58, p < 0.05). Seven patients presented with coronal imbalance immediately after surgery. However, only one of the seven patients presented with coronal imbalance at the last follow-up, and the other six achieved C7PL-CSVL distance within 10 mm.

CONCLUSIONS

In Lenke 5C patients, preoperative UIV translation and LIV tilt are two important parameters that can predict the immediate postoperative CB. During the postoperative follow-up, UIV tilt may play a very important role in compensating for postoperative coronal imbalance.

Late Proximal Pedicle Hook Migration Into Spinal Canal After Posterior Correction Surgery of Scoliosis Causing Neurologic Deficit: "Proximal Junctional Scoliosis"? Case Series and a Review of the Literature

STUDY DESIGN

Case series.

OBJECTIVES

We describe 4 patients with proximal pedicle hook migration as a late complication (greater than 12 months postoperatively) of posterior correction surgery in adolescent idiopathic scoliosis. We studied failure mechanisms and propose strategies for revision surgery.

SUMMARY OF BACKGROUND DATA

Few published cases of hook migration into the spinal canal concern mainly intra-operative or early postoperative dislodgement. Re-operation rates for adolescent idiopathic scoliosis are 2% to 10%.

METHODS

We retrospectively reviewed medical records and radiographic images in 4 patients with symptomatic pedicle hook migration into the spinal canal. We studied our scoliosis revision surgery rates over the past 10 years and reviewed the literature for instrumentation failure after scoliosis surgery.

RESULTS

Our total re-operation rate between January 2002 and April 2012 was 7.0% (56 of 800 procedures), with a mean follow-up of 61 months (range, 6-129 months). Proximal hook migration presented in 1.0% (8 of 800 procedures), including 4 into the spinal canal. These 4 patients presented with pain symptoms 19-78 months after uneventful index posterior correction surgery. In all 4 patients, radiographic imaging showed proximal pedicle hook migration into the spinal canal without proximal sagittal alignment problems. In all patients, spinal fusion was observed on computed tomographic imaging and at revision surgery. Revision surgery consisted of at least hook removal. In all 4 patients, symptoms completely resolved over time.

CONCLUSIONS

Hooks can migrate and potentially cause neurologic impairment and pain long after index surgery, despite the presence of solid spinal fusion. We believe this is partly the result of the surgical technique we used and have since abandoned, and partly the proximal spine settling and fusion mass deformation over time, which we call "proximal junctional scoliosis." We recommend computed tomographic imaging in case of postoperative symptoms and removal of hooks in case of hook migration into the spinal canal.

Adolescent idiopathic scoliosis treated with posteromedial translation: radiologic evaluation with a 3D low-dose system

PURPOSE

Computed tomography can be used for three-dimensional (3D) evaluation of adolescent idiopathic scoliosis (AIS) patients, but at the expense of high radiation exposure, and with the limitation of being performed in the supine position. These drawbacks can now be avoided with low-dose stereoradiography, even in routine clinical use. The purpose of this study was to determine the 3D postoperative correction of AIS patients treated by posteromedial translation.

METHODS

Forty-nine consecutive patients operated for AIS (Lenke 1-4) using posteromedial translation were included. Corrections were evaluated preoperatively, postoperatively and after at least 2 years using the EOS imaging system. 3D angles were measured in the plane of maximum deformity.

RESULTS

Mean number of levels fused and operative time were 13.5 ± 1 and 215 ± 25 min, respectively. Main thoracic, proximal thoracic, and lumbar curves corrections averaged 64.4 ± 18, 31 ± 10 and 69 ± 20 %, respectively. Mean T4-T12 kyphosis increased 18.8° ± 9° in the subgroup of hypokyphotic patients. Mean apical vertebral rotation reduction was 48.3 ± 20 %. Trunk height gain averaged 27.8 ± 14 mm. There was no pseudarthrosis or significant loss of correction in any plane during follow-up. Two patients (4 %) developed asymptomatic proximal junctional kyphosis, despite having normal thoracic kyphosis. Their sagittal balance was shifted posteriorly by 36 and 47 mm, respectively, by the operation, but revision surgery was not performed.

CONCLUSIONS

Low-dose stereoradiography provided 3D reconstructions of the fused and unfused spine in routine clinical use. Postoperative 3D analysis showed that posteromedial translation enhanced sagittal balance correction, without sacrificing frontal or axial correction of the deformity.

Serum titanium, niobium, and aluminum levels after instrumented spinal arthrodesis in children

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

To determine serum titanium, niobium, and aluminum levels in pediatric patients within the first postoperative year after instrumented spinal arthrodesis.

SUMMARY OF BACKGROUND DATA

Instrumented spinal arthrodesis is a common procedure to correct scoliosis and kyphosis. Titanium-based instrumentation is increasingly favored due to enhanced biomechanical properties, but concerns have arisen regarding metal debris release and the potential for local and systemic complications.

METHODS

The pattern of systemic metal release over time was evaluated by measuring serum titanium, niobium, and aluminum levels preoperatively and 1 week, 1 month, 6 months, and 12 months after instrumented spinal arthrodesis using a titanium alloy. Serum metal levels were measured using high-resolution inductively coupled plasma mass spectrometry.

RESULTS

Thirty-two patients were included in the study group. Mean age at surgery was 14.7 years. Preoperative and postoperative concentrations of serum titanium and niobium were significantly different (P = 0.0001). Median postoperative serum concentrations of titanium and niobium were elevated 2.4- and 5.9-fold above the normal range respectively with 95% and 99% of samples elevated postoperatively. A significant and rapid rise in serum titanium and niobium levels was observed within the first postoperative week, after which elevated serum levels persisted up to 12 months.

CONCLUSION

We report abnormally elevated serum titanium and niobium levels in patients with titanium-based spinal instrumentation up to 12 months. The long-term systemic consequences of debris generated by wear and corrosion of spinal instrumentation is unclear but concerning, particularly as these implants inserted into the pediatric population may remain in situ for beyond 6 decades.

Mid- to long-term outcomes in adolescent idiopathic scoliosis after instrumented posterior spinal fusion: a meta-analysis

STUDY DESIGN

Meta-analysis on mid- to long-term outcomes in adolescent idiopathic scoliosis after instrumented posterior spinal fusion.

OBJECTIVE

To compare mid- to long-term outcomes and complications of the most commonly used instrumentation systems in adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

A meta-analysis of mid- to long-term results of different methods of instrumentation, including the most currently used all-pedicle screw construct, is lacking.

METHODS

A structured literature review was conducted for studies concerning management of patients with adolescent idiopathic scoliosis with instrumented posterior fusion. Pooled means, standard deviations, and sample sizes were either identified or calculated on the basis of the results of each study.

RESULTS

Meta-analyses were performed on outcomes from 27 studies. Overall, 1613 patients who had been treated with Harrington rods, 361 patients who had undergone Cotrel-Dubousset instrumentation, and 298 patients who managed with all-pedicle screw constructs were reviewed. The mean follow-up was 14.9 years. Cotrel-Dubousset and pedicle screw instrumentations achieved a significantly greater degree of correction of the thoracic curve than Harrington rods (40.3° vs. 14.7°; P < 0.001 and 21.9° vs. 14.7°; P = 0.005, respectively). Cotrel-Dubousset technique achieved a significantly higher degree of correction than all-pedicle screw construct in both the thoracic (40.3° vs. 21.9°, respectively; P < 0.001) and lumbar curves (37.2° vs. 16°, respectively; P < 0.001). Similarly, Cotrel-Dubousset construct achieved a greater correction of both thoracic kyphosis (33.5° vs. 23°, respectively; P < 0.001) and lumbar lordosis (46° vs. 50.7°, respectively; P = 0.002) than pedicle screws. All-pedicle screw fixation was associated with the lower risk of pseudarthrosis, infection, neurological deficit, and reoperation.

CONCLUSION

This study confirms the negative effect of Harrington rods on sagittal alignment. We further found that the degree of correction in the coronal and sagittal planes was higher after Cotrel-Dubousset instrumentation than all-pedicle screw fixation. All-pedicle screw constructs offered the lower risk of mid- to long-term complications and revision surgery.

Current concepts and controversies on adolescent idiopathic scoliosis: Part I

Adolescent idiopathic scoliosis is the most common spinal deformity encountered by General Orthopaedic Surgeons. Etiology remains unclear and current research focuses on genetic factors that may influence scoliosis development and risk of progression. Delayed diagnosis can result in severe deformities which affect the coronal and sagittal planes, as well as the rib cage, waistline symmetry, and shoulder balance. Patient's dissatisfaction in terms of physical appearance and mechanical back pain, as well as the risk for curve deterioration are usually the reasons for treatment. Conservative management involves mainly bracing with the aim to stop or slow down scoliosis progression during growth and if possible prevent the need for surgical treatment. This is mainly indicated in young compliant patients with a large amount of remaining growth and progressive curvatures. Scoliosis correction is indicated for severe or progressive curves which produce significant cosmetic deformity, muscular pain, and patient discontent. Posterior spinal arthrodesis with Harrington instrumentation and bone grafting was the first attempt to correct the coronal deformity and replace in situ fusion. This was associated with high pseudarthrosis rates, need for postoperative immobilization, and flattening of sagittal spinal contour. Segmental correction techniques were introduced along with the Luque rods, Harri-Luque, and Wisconsin systems. Correction in both coronal and sagittal planes was not satisfactory and high rates of nonunion persisted until Cotrel and Dubousset introduced the concept of global spinal derotation. Development of pedicle screws provided a powerful tool to correct three-dimensional vertebral deformity and opened a new era in the treatment of scoliosis.

Pain and disability following fusion for idiopathic adolescent scoliosis: prevalence and associated factors

Study design: Retrospective prognostic study.

Objectives: To describe the prevalence of pain following fusion for adolescent idiopathic scoliosis and to identify factors associated with pain and disability.

Methods: From 126 consecutive patients surgically treated for scoliosis between 1997 and 2007, 104 (82.5%) completed SRS-22 and ODI questionnaires at a last follow-up (mean, 4.8 years; range 1–11.2 years). Prevalence of pain and disability were determined from SRS questions 1 and 9 respectively, with “any” pain or decrease in activity considered clinically significant. SRS Pain Domain Scores (PDS) were also evaluated.

Results: Most participants reported “no pain” (38.5%) or “mild pain” (30.8%) and 72.1% of participants reported a current work/school activity level of 100% normal. An association between instrument type and the presence of any pain in the previous 6 months was noted (P = .022). Instrument type was the only factor that was significantly associated with the PDS (P = .0052).

Conclusions: The high percentage of patients reporting no pain or mild pain may suggest overall success of the procedures. Although an association between instrument type and pain was seen, unmeasured factors that contributed to the decision of what instrument to use may confound the relationship. From these data a causal inference cannot be made.

Circumferential fusion with anterior strut grafting and short-segment multipoint posterior fixation for burst fractures in skeletally immature patients: a preliminary report

BACKGROUND

The Universal Clamp (UC) is a novel vertebral anchor consisting of a sublaminar polyester band connected to fusion rods by a titanium jaw locked with a screw. The authors prospectively studied patients treated for thoracic or lumbar burst fractures with short pedicle screw constructs reinforced with UCs to prevent screw pullout.

METHODS

Eleven patients below 18 years of age underwent 2-stage circumferential fusion for complete burst fractures (Magerl A 3.3). Two pedicle screws reinforced by 2 UCs were inserted in the vertebra proximal to the fracture and 2 pedicle screws reinforced by 2 UCs were inserted in the vertebra distal to the fracture. Within 7 days, cages filled with cancellous bone graft were added for anterior column support. T12 was fractured in 3 patients, L1 in 4, L3 in 2, and L4 in 2 patients. Preoperatively, 10 patients were neurologically intact (Frankel E) and 1 patient had an incomplete spinal cord injury (Frankel C).

RESULTS

Mean operative duration for the posterior and anterior procedures was 110±24 and 120±35 minutes, respectively. Average intraoperative blood loss was 355±60 mL. Mean hospital stay was 11±2 days and follow-up averaged 36.1±5 months. Mean kyphotic deformity was corrected from 25±9 to 5.3±4.5 degrees postoperatively (79%), without subsequent loss of correction (P=0.17). Regional kyphosis improved by 20±8 degrees postoperatively, without subsequent loss of correction (P=0.09). No intraoperative complication was observed. There was no neurological deterioration. The patient who had a Frankel C lesion recovered 1 Frankel level (Frankel D) at final follow-up. None of the patients exhibited significant correction loss during follow-up, and there was no pseudarthrosis.

CONCLUSIONS

Thoracic and lumbar complete burst fractures in skeletally immature patients can be treated using anterior bone graft cages and posterior instrumented fusion augmented with UCs to prevent pedicle screw pullout. With these constructs, which are short to preserve mobile intervertebral segments, kyphosis was corrected, fusion achieved, and correction maintained in all subjects without neurological worsening.

LEVEL OF EVIDENCE

Level IV.

Anterior versus posterior approach in 3D correction of adolescent idiopathic thoracic scoliosis: a meta-analysis

PURPOSE

Systematic review was conducted to compare effectiveness and safety of anterior and posterior surgical approach in 3D correction of adolescent idiopathic thoracic scoliosis.

METHODS

Data sources were MEDLINE and SCOPUS databases. We included studies on the use of either anterior or posterior instrumentation, or their combination, in surgical correction of adolescent idiopathic thoracic scoliosis, with at least 10 enrolled patients, aged less than 20 years at the time of surgery, and a follow-up of at least 24 months. A study was eligible if it reported the number of patients, mean estimate and dispersion of three key outcome measures (frontal and sagittal Cobb angle, apical vertebra rotation according to Perdriolle) at three measurement points (preoperatively, postoperatively, at follow-up). The quality of studies was assessed using the scale by Pilkington.

RESULTS

Although 24 articles met the inclusion criteria, no randomized controlled trials (RCT) was identified. None of the articles was of high quality. Both instrumentations provided a similar degree of reduction of frontal Cobb angle. Long-term effects of surgical correction on the sagittal Cobb angle seemed to be more stable in patients treated by posterior approach, while the anterior approach was more effective in the reduction of apical vertebral rotation. The surgery parameters were more favorable for anterior approach, particularly for the number of fused vertebrae.

CONCLUSIONS

Although the available evidence favors neither of the two approaches, our study revealed several important issues: the reports are heterogeneous and provide incomplete relevant information. High quality studies, particularly RCT, are called for.

LEVEL OF EVIDENCE

Level II.

Health-related quality of life and low back pain of patients surgically treated for scoliosis after 21 years or more of follow-up: comparison among nonidiopathic scoliosis, idiopathic scoliosis, and healthy subjects

STUDY DESIGN

A case-control study.

OBJECTIVE

To compare health-related quality of life and low back pain of healthy subjects with those of patients with nonidiopathic scoliosis (non-IS) and idiopathic scoliosis (IS) 21 years or more after surgery.

SUMMARY OF BACKGROUND DATA

There have been a very small number of reports on long-term results of surgery for non-IS. There have not been any reports that compare non-IS, IS, and healthy subjects.

METHODS

The subjects with scoliosis were 602 patients who had undergone surgery between 1968 and 1988. The Scoliosis Research Society Patient Questionnaire (SRS-22), Roland-Morris Disability Questionnaire (RDQ), and our institution's original questionnaire were used for evaluating long-term clinical outcomes. The 136 respondents consisted of 56 patients with non-IS (non-IS group) and 80 patients with IS (IS group). The control group (CTR group) consisted of 80 healthy volunteers who were age- and body mass index-matched to the scoliosis groups.

RESULTS

In the SRS-22, the 3 groups had no significant differences in pain and mental health. For function and self-image, the non-IS group and the IS group had a significantly lower score than the CTR group. In the RDQ, the non-IS group had significantly more severe low back pain than the CTR group. There was no significant difference in low back pain between the non-IS group and IS group or between the IS group and CTR group. The non-IS group had a significantly lower marriage rate than the IS and CTR groups.

CONCLUSION

The patients with non-IS and IS had similar health-related quality of life and low back pain. The patients with non-IS were found to have lower function and self-image in the SRS-22 questionnaire and more severe low back pain in the RDQ than healthy subjects. The patients with non-IS had a significantly lower marriage rate than the other 2 groups.

Sagittal alignment of the cervical spine in adolescent idiopathic scoliosis treated by posteromedial translation

PURPOSE

To analyze postoperative changes in the cervical sagittal alignment (CSA) of patients with AIS treated by posteromedial translation.

METHODS

49 patients with thoracic AIS underwent posterior arthrodesis with hybrid constructs, combining lumbar pedicle screws and thoracic universal clamps. Posteromedial translation was the main correction technique used. 3D radiological parameters were measured from low-dose biplanar radiographs. CSA was assessed using the C2C6 angle, and the central hip vertical axis (CHVA) was used as a reference axis to evaluate patients' balance.

RESULTS

Preoperatively, 58 % of patients had thoracic hypokyphosis, and 79 % had a kyphotic CSA. Significant correlation was found (r = 0.45, P = 0.01) between thoracic hypokyphosis and cervical kyphosis. Increase in T4-T12 thoracic kyphosis (average 14.5° ± 10°) was associated with significant decrease in cervical kyphosis in the early postoperative period. The CSA further improved spontaneously during follow-up by 7.6° (P < 0.0001). Significant positive correlation (r = 0.32, P = 0.03) was found between thoracic and cervical improvements. At latest follow-up, 94 % of the patients were normokyphotic and 67 % had a CSA in the physiological range. Sagittal balance of the thoracolumbar spine was not significantly modified postoperatively. However, the procedure significantly changed the position of C2 in regard to the CHVA (C2-CHVA), which reflects headposition (P = 0.012). At last follow-up, the patients sagittal imbalance was not significantly different from the preoperative imbalance (P = 0.34).

CONCLUSIONS

Thoracic hypokyphosis and cervical hypolordosis, observed in AIS, can be improved postoperatively, when the posteromedial translation technique is used for correction. The cervical spine remains adaptable in most patients, but the proportion of patients with physiological cervical lordosis at final follow-up remained low (24.5 %).

Body appearance and quality of life in adult patients with adolescent idiopathic scoliosis treated with a brace or under observation alone during adolescence

STUDY DESIGN

The Scoliosis Research Society (SRS) brace study (published in the JBJS-A, 1995) was comprised of patients with adolescent idiopathic scoliosis with moderate curve sizes (25°-35°). Forty observed and 37 braced patients (77% of the original group) attended a follow-up, a mean of 16 years after onset of maturity.

OBJECTIVE

To analyze whether the subjectively evaluated present body appearance affects outcome as measured by quality of life in adult patients, previously treated by observation alone (nonbraced) or with a brace during adolescence.

SUMMARY OF BACKGROUND DATA

Few reports exist where validated outcome measures for body appearance have been used.

METHODS

Two quality-of-life questionnaires, the Scoliosis Research Society-22 (SRS-22) questionnaire and the 36-Item Short-Form Survey Instrument (SF-36), were answered. The patient's opinion on body appearance was evaluated pictorially (i.e., sketches) using the spinal appearance questionnaire, in which 7 aspects of asymmetry are graded. These scores were compared with curve sizes, scoliometer measurements for grading trunk asymmetry, and quality-of-life measures.

RESULTS

At follow-up, both groups were similar in terms of age (mean = 32 years) and curve size (mean = 35°). Distortion was inversely related to SRS-22 total score and satisfaction/dissatisfaction with management subscore, but not related to the SRS-22 function subscore. No difference was found between the groups in terms of trunk rotation, where the means were 10.7° and 10.8° for the nonbraced and braced patients, respectively. The nonbraced patients estimated that their body appearance was significantly less distorted than the braced patients (mean = 12.9 and 15.0, respectively; P = 0.0028).

CONCLUSION

Patients who experienced less body asymmetry were more satisfied with treatment and had a better quality of life. In spite of similar curve sizes and trunk rotation in both groups, the nonbraced patients felt that their body appearance was less distorted than that of the braced patients.

Long-term clinical outcomes of surgery for adolescent idiopathic scoliosis 21 to 41 years later

STUDY DESIGN

A case control study.

OBJECTIVE

To determine the clinical outcome of middle-aged patients surgically treated for adolescent idiopathic scoliosis and to compare their outcomes with assessments of age- and sex-matched healthy controls.

SUMMARY OF BACKGROUND DATA

Several long-term follow-up studies have been published on the clinical outcomes of surgical treatment for adolescent idiopathic scoliosis in patients who have reached their 20s or 30s. However, clinical outcomes in patients who have reached middle age remain unknown.

METHODS

This study included 256 patients surgically treated for adolescent idiopathic scoliosis (AIS) between 1968 and 1988. The Scoliosis Research Society Patient Questionnaire (SRS-22) and Roland-Morris Disability Questionnaire (RDQ) were used for evaluating long-term clinical outcomes. Sixty-six (25.8%; 62 females, 4 males; mean age, 46.0 years [range 34-56]) of the 256 patients responded to the questionnaires. The mean follow-up period was 31.5 (range 21-41) years. Seventy-six healthy age- and sex-matched individuals with neither a history of spinal surgery nor scoliosis were selected as a control (CTR) group.

RESULTS

On the basis of the SRS-22 responses, AIS patients had significantly decreased function (AIS: 4.3 ± 0.6, CTR: 4.7 ± 0.5, P < 0.01) and decreased self-image (AIS: 3.0 ± 0.8, CTR: 3.7 ± 0.5, P < 0.01) in comparison with the controls, but the 2 groups were similar with respect to pain (AIS: 4.3 ± 0.6, CTR: 4.2 ± 0.5, P = 0.14) and mental health (AIS: 3.9 ± 0.9, CTR: 3.7 ± 0.7, P = 0.14). The RDQ responses indicated that low back pain was not significantly increased in the AIS group compared with the CTR group (AIS: 1.8 ± 3.5, CTR: 1.4 ± 3.1, P = 0.36).

CONCLUSION

Surgery had no demonstrable adverse effects on pain or mental health in these middle-aged AIS patients 21-41 years after surgery, although the AIS patients did have significantly lower function and lower self-image than the controls.

Simultaneous translation on two rods to treat adolescent idiopathic scoliosis: radiographic results in coronal, sagittal, and transverse plane of a series of 62 patients with a minimum follow-up of two years

STUDY DESIGN

Retrospective analysis of a consecutive cohort of 62 adolescent patients treated by posterior spinal fusion (PSF) with a minimum follow-up of 2 years.

OBJECTIVE

To present sagittal and coronal results of a specific method of reduction: the simultaneous translation on 2 rods (ST2R).

SUMMARY OF BACKGROUND DATA

The long-term outcome of surgically treated scoliosis is dependent not only on the coronal correction but also on restoration of sagittal curves. Recent publications confirm the moderate correction of thoracic hypokyphosis by posterior instrumentation with hooks or pedicle screws.

METHODS

Radiographic parameters were measured preoperatively and at 6 weeks, 1 year, and last follow-up (between 2 and 7.4 years) in a consecutive cohort of 62 patients with adolescent idiopathic scoliosis (AIS) treated by PSF. All operative procedures were performed by the same surgeon using stable anchorages such as screws or self-stabilizing claws. The screws and claws included a polyaxial-threaded extension, which was fixed to the rod with connecting clamps. Reduction of the deformity was obtained by gradual and alternate tightening of the nuts on all threaded extensions on both rods, which allowed the vertebrae to gradually approach the rods while the translation maneuver was performed.

RESULTS

In the coronal plane, the average main curve was reduced from 51° to 16° and maintained 70% of correction at last follow-up. In the sagittal plane, for patients with hypokyphosis (27 cases < 20°), the average kyphosis angle was significantly improved from 9° to 29° and maintained during follow-up (32°) with a mean gain of 23° (P < 0.0001). Only 1 patient reported hypokyphosis (18°) at last follow-up. For patients with normal kyphosis, the average gain was 8°.

CONCLUSION

In a large consecutive cohort, reduction of scoliosis by ST2R is a simple method that allows 70% of correction in the coronal plane, equivalent to screw instrumentations, and a restoration of normal thoracic kyphosis.

Fixation points within the main thoracic curve: does more instrumentation produce greater curve correction and improved results?

STUDY DESIGN

Prospective consecutive multicenter case series.

OBJECTIVE

To compare fixation type and amount to curve correction controlled for curve flexibility.

SUMMARY OF BACKGROUND DATA

The enhanced spinal purchase from segmental fixation should increase the force implants can exert without failure. This study evaluates whether this translates into correction beyond that expected from preoperative bending radiographs in thoracic curves where maximum correction was feasible (1A, 1B, and nonselective 1C fusions).

METHODS

One hundred seventy-one Lenke type 1 curves (118 1A, 36 1B, 23 1C) with 2-year follow-up were evaluated for the number and type of fixation points within the main curves compared to the correction obtained on preoperative bend films. SRS scores were compared to the amount of correction.

RESULTS

The number of fixation points both within the curve (P = 0.01) and for each vertebral body (P = 0.002) was larger for curves with greater correction compared to the bend films than those with less correction. Overall absolute correction was best for all screw and screw and wire constructs, followed by hook and screw, and least with hooks. However, compared to the bend films, these differences were not significant (P = 0.132). For all groups, the SRS scores significantly improved (P < 0.001), and was slightly more notable for the all screw constructs than other instrumentation patterns (P = 0.023). However, there were no significant difference in this improvement between those correcting more and those correcting less than the bend films (P = 0.578).

CONCLUSION

Absolute curve correction improved most with all pedicle screw and screw and wire constructs, but, when compared to bending films, the number of fixation points is more important than fixation type for curve correction. Although SRS scores improved the most in those with all screw constructs, the significance of this improvement is uncertain, and the SRS scores did not relate to whether curve correction was more or less than the bend films.

Use of the Universal Clamp in adolescent idiopathic scoliosis for deformity correction and as an adjunct to fusion: 2-year follow-up

PURPOSE

Among posterior surgical techniques for treating adolescent idiopathic scoliosis (AIS), hybrid constructs with pedicle-screw fixation in the lumbar spine and other anchors in the thoracic spine have been reported to provide to be of more physiological value in postoperative thoracic kyphosis than all-screw constructs. The Universial Clamp (UC) equipped with a soft sublaminar band is a relatively new thoracic anchor that can be used in hybrid constructs. A dedicated reduction tool that applies traction to the sublaminar band permits gentle translation of the thoracic curve to the precontoured fusion rods, which have been previously anchored distally by pedicle screws and proximally by hooks in a claw configuration. The aim of this study was to evaluate radiographic results of AIS treatment using UC hybrid constructs.

METHODS

This was a prospective case series in which 29 consecutive patients with Lenke type 1, 2 or 3 AIS operated on by two surgeons in two centers were followed for 24 months. Necessity for anterior release was an exclusion criterion.

RESULTS

A total of 5.4 ± 1.4 UCs were used per patient. The major thoracic curve was reduced from 55 ± 7° to 14 ± 6° at 1 month and 17 ± 6° at 24 months (correction 70%) without complications. In the patients who had less than 20° of T5-T12 kyphosis preoperatively, thoracic kyphosis improved from 14 ± 4° to 20 ± 3° at 3 months and 24 ± 9° at 24 months. In the other patients, preoperative thoracic kyphosis (27° ± 6°) was unchanged by the operation.

CONCLUSION

UC hybrid constructs appear to safely provide satisfying coronal correction while consistently improving thoracic kyphosis in patients who also have preoperative hypokyphosis. We hypothesize that diminution in thoracic kyphosis was consistently avoided due to the straightforward traction of the spine to the fusion rods into which the chosen kyphosis was contoured by the surgeon before applying the reduction tool to the sublaminar bands.

Prediction of postoperative trunk imbalance after posterior spinal fusion with pedicle screw fixation for adolescent idiopathic scoliosis

The objective of this retrospective study was to explore, which radiographic parameters, immediately after posterior spinal fusion with pedicle screw fixation for adolescent idiopathic scoliosis (AIS), best correlate with subjacent disc wedging at a minimum of 2-year follow-up. Sixty-four consecutive AIS patients who underwent posterior pedicle screw-only instrumentation were studied. Preoperative and postoperative radiographs were obtained to measure various parameters regarding global coronal, shoulder, sagittal, and regional balance. Specific correlation of these parameters to selected 2-year postoperative disc wedging and lowest-instrumented vertebra (LIV) tilt and translation were analyzed. The average lateral disc opening changed from 4.59±4.75 preoperatively to 1.46±2.82 at 2 weeks and 2.81±6.43 at 2 years postoperatively. Two-year postoperative lateral disc opening significantly correlated with the 2-week postoperative lateral disc opening, C7 plumbline relative to the posterior-superior corner of the first sacral vertebra distance, and LIV-center sacral vertical line (CSVL) distance (r=0.7433, P<0.0001). The two-year postoperative LIV tilt significantly correlated with the 2-week postoperative LIV tilt, T12-LIV lordosis, LIV-CSVL distance, and C7-CSVL distance (r=0.8879, P<0.0001). Two-year postoperative LIV-CSVL significantly correlated with 2-week postoperative LIV-CSVL distance and lateral disc opening (r=0.6104, P<0.0001). Two-year postoperative disc wedging, LIV tilt, and LIV translation occurred most often when disc wedging and LIV deviation or obliquity existed immediately postoperatively. This study identified a potential indicator for AIS repair. Preoperative surgical planning and intraoperative correction are important for avoiding subjacent regional imbalance after scoliosis fusion.

Evaluation of spinal instrumentation rod bending characteristics for in-situ contouring

Bending characteristics were studied in rods used for spinal instrumentation at in-situ contouring conditions. Five groups of five 6 mm diameter rods made from: cobalt alloy (VITALLIUM), titanium-aluminum-vanadium alloy (SDI™), β-titanium alloy (TNTZ), cold worked stainless steel (STIFF), and annealed stainless steel (MALLEABLE) were studied. The bending procedure was similar to that typically applied for in-situ contouring in the operating room and included two bending cycles: first--bending to 21-24° under load with further release of loading for 10 min, and second--bending to 34-37° at the previously bent site and release of load for 10 min. Applied load, bending stiffness, and springback effect were studied. Statistical evaluation included ANOVA, correlation and regression analysis. TNTZ and SDI™ rods showed the highest (p < 0.05) springback at both bending cycles. VITALLIUM and STIFF rods showed mild springback (p < 0.05). The least (p < 0.05) springback was observed in the MALLEABLE rods. Springback significantly correlated with the bend angle under load (p < 0.001). To reach the necessary bend angle after unloading, over bending should be 37-40% of the required angle in TNTZ and SDI™ rods, 27-30% in VITALLIUM and STIFF rods, and around 20% in MALLEABLE rods.

Hybrid constructs for tridimensional correction of the thoracic spine in adolescent idiopathic scoliosis: a comparative analysis of universal clamps versus hooks

STUDY DESIGN

Retrospective study of prospectively collected data.

OBJECTIVE

Compare Universal Clamps (UCs) and hooks for the thoracic correction of adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

In scoliosis surgery, sagittal correction is as important as frontal correction due to the risk of junctional kyphosis. Compared to all-screw constructs, hybrid constructs with lumbar pedicle screws and thoracic hooks or sublaminar wires have been shown to achieve similar coronal correction while providing superior postoperative thoracic kyphosis. The authors used a novel sublaminar thoracic implant, the UC with improvements over sublaminar wires. Hybrid constructs using thoracic UCs were compared to those with thoracic hooks.

METHODS

This series involved 150 patients treated for AIS with hybrid constructs. A total of 75 consecutive patients operated from 2001 to 2003, who had thoracic hooks with in situ contouring, distraction, and compression (Group 1), were compared to 75 consecutive patients operated from 2004 to 2006, who had thoracic UCs with posteromedial translation (Group 2). All had intraoperative somatosensory/motor-evoked potential monitoring and at least 2-years follow-up.

RESULTS

Except for follow-up (longer in Group 1), the 2 groups were similar before surgery. The UCs achieved better thoracic coronal correction (P < 0.001), Cincinnati index (P < 0.001), kyphosis (P = 0.02), and apical rotation (P < 0.001). In normokyphotic or hypokyphotic patients, the UC corrected thoracic kyphosis by 11.2 degrees (55%) versus 0.4 degrees (2%) achieved by hooks (P < 0.0001). These differences were stable at last follow-up. There were no intraoperative complications or changes in somatosensory/motor-evoked potentials. UC reduced operative time by 20% (60 minutes; P < 0.001) and blood loss by 23% (250 mL; P < 0.001).

CONCLUSION

Although both of these hybrid constructs efficaciously corrected the coronal and axial deformities in AIS, the results of the UC technique were superior to those achieved with hooks in all 3 planes, especially the sagittal plane. Moreover, the UC technique is straightforward and safe, reducing both operative duration and blood loss.

Health-related quality of life in untreated versus brace-treated patients with adolescent idiopathic scoliosis: a long-term follow-up

STUDY DESIGN

The previous Scoliosis Research Society brace study (JBJS-A, 1995) included patients with adolescent idiopathic scoliosis (AIS) with moderate curve sizes (25 degrees -35 degrees). The Swedish patients in this study were examined in a long-term follow-up.

OBJECTIVE

The aim was to analyze and compare quality of life in adulthood between AIS patients who were only observed or treated with a brace during adolescence.

SUMMARY OF BACKGROUND DATA

Quality of life as measured by the SRS-22 has not previously been presented for adult untreated AIS patients.

METHODS

Forty patients who were only observed (due to a curve increase of less than 6 degrees until maturity), and 37 brace-treated patients attended the complete follow-up, including clinical and radiologic examination, and answered 2 quality of life questionnaires (SRS-22 and Short Form-36 [SF-36]).

RESULTS

No differences were found between the groups in terms of age at follow-up (mean: 32 years), follow-up time after maturity (mean: 16.0 years), and curve size at inclusion (mean: 30 degrees) or at follow-up (mean: 35 degrees). The SRS-22/total score was a mean of 4.2 for braced patients and 4.1 for only observed patients. Neither total scores/subscales of the SRS-22 or SF-36 differed significantly between the groups. For the SF-36, no differences in relation to the Swedish age-matched norm scales were found for either group.

CONCLUSION

Patients with moderate AIS report good quality of life in their 30s, as measured by both the SRS-22 and SF-36, regardless of whether they received no active treatment or were brace treated during adolescence. Neither of the groups displayed any difference compared with the age-matched norm groups for the SF-36.

Spinal loop rectangle and sub laminar wiring as a technique for scoliosis correction

BACKGROUND

Most literature popularizes the efficacy of third generation instrumentation in the surgical correction of spinal deformities. A cheap and effective scoliotic deformity correction method is reviewed in this article. The aim of this study is to evaluate the efficacy of spinal loop rectangle and sub laminar wires as a modality for spinal deformity correction and its co-relation with patients' satisfaction and clinical outcome.

MATERIAL AND METHODS

Thirty six patients of scoliotic spinal deformities with various etiologies (congenital-4, idiopathic- 25, neurofibromatosis-3, neuromuscular-2 and 'syndromic'-3) with ages ranging from 8 to 23 years underwent corrective posterior spinal arthrodesis with stainless steel Hartshill loop rectangle and sublaminar wires. Clinicoradiological evaluation was done at an average follow-up of 6 (1/2) years (min-2 (1/2), years). Along with clinicoradiological outcome, patient satisfaction (as per the SRS 24), was accounted.

RESULTS

Average preoperative Cobb's angle were 73.25 degrees in the entire group and 66.48 degrees in the idiopathic group. Average percentage correction was 64.34% in the entire group and the (average degree of correction was 47.13). In the idiopathic group, the respective values were 69.19% and 46 degrees . Loss of correction in the whole group was 2.2 degrees at two year follow up. Sagittal profiles, truncal balance were well corrected too; minimal complications were seen. Patient satisfaction results were encouraging in 36 patients as per - SRS24). About 80.2% patients were ready to undergo the same surgery if required. (SRS24).

CONCLUSION

Segmental spinal fixation with locally made spinal loop rectangle and sublaminar wires is comparable as a modality to correct scoliotic spinal deformities.

Quality of life in patients treated surgically for scoliosis: longer than sixteen-year follow-up

STUDY DESIGN

A retrospective study.

OBJECTIVE

To evaluate the long-term quality of life (QOL) of patients treated surgically for scoliosis.

SUMMARY OF BACKGROUND DATA

Measures of long-term outcome after surgery for scoliosis have focused mainly on radiologic changes. However, QOL issues such as working status and marital status are the subjects of greatest concern for patients who will undergo surgical treatment for scoliosis.

METHODS

Thirty-two patients treated surgically for scoliosis between 1976 and 1989 were included in this study. The mean duration of follow-up was 21.1 years. Eighteen patients had adolescent idiopathic scoliosis, 8 congenital scoliosis, and 6 symptomatic scoliosis. We evaluated long-term outcome by direct interview with patients. Working status, marital status, and childbearing were determined in addition to clinical and radiologic evaluation. Patients were also asked to fill out the short form (SF)-36 and Scoliosis Research Society (SRS)-22 questionnaires.

RESULTS

Twenty-seven patients (84.4%) were or had been engaged in various occupations without marked difficulty. Although none of the male patients was married, 62.5% of the female patients were married. Half of the female patients had delivered babies after surgery, and the mean number of such children was 1.83. On the SF-36, none of the scores for subjects with idiopathic or congenital scoliosis were markedly different from those for age-matched healthy controls. Multivariate logistic regression analysis revealed that marked preoperative Cobb angle and positive sagittal balance at the most recent follow-up were significantly associated with increased odds ratio for poor scores on the SRS-22.

CONCLUSION

We evaluated long-term QOL in patients treated surgically for scoliosis, and found that it was not impaired, particularly in the case of patients with idiopathic or congenital scoliosis. Larger preoperative Cobb angle and positive sagittal balance at the most recent follow-up were related to poor outcome in QOL as assessed by the SRS-22.

Low back pain in patients treated surgically for scoliosis: longer than sixteen-year follow-up

STUDY DESIGN

A retrospective study.

OBJECTIVE

To evaluate long-term outcome regarding low back pain (LBP) in patients treated surgically for scoliosis.

SUMMARY OF BACKGROUND DATA

Measures of long-term outcome after surgery for scoliosis have focused mainly on radiologic changes. However, subjective symptoms such as LBP after surgical treatment are of great concern to patients who undergo surgical treatment for scoliosis.

METHODS

Thirty-two patients treated surgically for scoliosis between 1976 and 1989 were included in this study. The mean duration of follow-up was 21.1 years. Eighteen patients had adolescent idiopathic scoliosis, 8 had congenital scoliosis, and 6 had symptomatic scoliosis. We evaluated long-term outcome by direct interview. Degree of LBP was evaluated by visual analogue scale score and Moskowitz classification in addition to clinical and radiologic evaluation. Patients were also asked to complete the SF-36 questionnaire.

RESULTS

Mean visual analogue scale score at the latest follow-up was 21 (0-80), and 15% of patients had occasional or frequent LBP in Moskowitz classification. On the SF-36, score for bodily pain was not markedly different from that for age-matched controls. Among radiologic findings, level of distal fusion had no effect on the incidence or severity of LBP. Furthermore, preoperative Cobb angle, latest Cobb angle, and degenerative changes of subjacent segment each exhibited no correlation with degree of LBP, either. On the other hand, sagittal balance was a factor affecting LBP following scoliosis surgery.

CONCLUSION

We evaluated long-term outcomes regarding LBP following scoliosis surgery. Regardless of residual back deformity, LBP was found to be no more frequent than in the normal population in Japan. Positive sagittal balance at the latest follow-up was a factor significantly contributing to LBP following scoliosis surgery.

Adolescent idiopathic scoliosis (AIS) treated with arthrodesis and posterior titanium instrumentation: 8 to 12 years follow up without late infection

BACKGROUND

There are no data in the peer-reviewed literature regarding long term results in patients treated for AIS with a posterior titanium instrumentation. Therefore we assessed the outcome in 50 patients treated by titanium implant.

METHODS

A total of 50 patients with a mean age of 16.6 years were treated. In all patients, titanium hooks and pedicle screws were used in combination. The demographic data and the pre- and post-operative radiographs of all 50 patients were re-examined, and 49 of the 50 patients (98%) attended a radiological and clinical follow up-examination on average 10.1 years post-operatively. The clinical results were recorded by means of the SRS 24 questionnaire.

RESULTS

In the frontal plane, the mean pre-operative thoracic and lumbar curve had been 62.4 degrees and 43.5 degrees respectively, post-operatively the curves were reduced to 26.9 degrees and 16.3 degrees , resulting in a correction rate of 56.9% for thoracic and 62.5% for lumbar curve. At the follow up-evaluation, the Cobb angle of the thoracic and lumbar curve was 31.0 degrees and 21.3 degrees respectively, giving a final correction rate of 50.3% for thoracic, and 51.0% for lumbar curve. 7 of the 50 patients (14.3%) had undergo revision surgery for complications, but complete implant removal was necessary in only one case. Analysis of the SRS 24 questionnaire showed an average score of 95.8 points.

CONCLUSION

Posterior titanium instrumentation is a safe and effective procedure in the surgical correction of AIS. In this retrospective study with small patient number, it shows favourable long-term results; in particular, the loss of correction is low, no late infection occurred and there was a very high survival rate of the implant itself.

Efficacy and safety of posteromedial translation for correction of thoracic curves in adolescent idiopathic scoliosis using a new connection to the spine: the Universal Clamp

Correction of adolescent idiopathic scoliosis (AIS) has been reported with various systems. All-screw constructs are currently the most popular, but they have been associated with a significant decrease in thoracic kyphosis, with a potential risk of junctional kyphosis, not observed with hybrid constructs in the literature. In addition, it is important to weigh potential advantages of pedicle screw fixation against risks specific to its use. Because hybrid constructs are associated with a lower risk of complications and better sagittal correction than all-screw constructs, at present we use lumbar pedicle screws combined with a new sublaminar connection to the spine (Universal Clamps) at thoracic levels. The purpose of this study was to determine the efficacy and safety of the Universal Clamp (UC) posteromedial translation technique for correction of AIS. Seventy-five consecutive patients underwent posterior spinal fusion and hybrid instrumentation for progressive AIS. Correction was performed at the thoracic level using posteromedial translation. At the lumbar level, correction was performed using in situ contouring and compression/distractions maneuvers. A minimum 2-year follow-up was required. Medical data and radiographs were prospectively analyzed and compared using a paired t test. The average age at surgery was 15 years and 4 months (+/-19 months). The average number of levels fused was 12+/-1.6. The mean follow-up was 30+/-5 months. The average preoperative Cobb angle of the major curve was 60 degrees+/-20 degrees. The immediate postoperative major curve correction averaged 66+/-13%. The average loss of correction of the major curve between the early postoperative assessment and latest follow-up was 3.5 degrees+/-1.4 degrees . The mean Cincinnati correction index was 1.7+/-0.8 postoperatively, and 1.57+/-1 at last follow up. The mean rotation of the apical vertebra was corrected from 23.3 degrees+/-9 degrees preoperatively to 7.3 degrees+/-5 degrees at last follow up (69% improvement, P<0.0001). In the sagittal plane, the mean thoracic kyphosis improved from 23.8 degrees+/-14.2 degrees preoperatively to 32.3 degrees+/-7.3 degrees at last follow up. For the 68 patients who had a normokyphotic or a hypokyphotic sagittal modifier, thoracic kyphosis increased from 20.5 degrees+/-9.9 degrees to 31.8 degrees+/-7.4 degrees, corresponding to a mean kyphosis correction of 55% at last follow up. No intraoperative complication occurred and none of the patients developed proximal junctional kyphosis during the follow up. The principal limitation of the UC technique was the rate of proximal posterior prominence (14.6%), leading us to recommend the use of conventional claws at the upper extremity of the construct. The technique was safe, and reduced operative time, radiation exposure, and blood loss. While achieving correction of deformity in the coronal and axial planes equivalent to the best reported results of all-screw or previous hybrid constructs, the UC hybrid technique appears to provide superior correction in the sagittal plane. The excellent outcome in all three planes was maintained at 2 year follow up.

Discrepancy between radiographic shoulder balance and cosmetic shoulder balance in adolescent idiopathic scoliosis patients with double thoracic curve

Shoulder balance is one of the key components to the body deformity in adolescent idiopathic scoliosis (AIS) patients with double thoracic curve and shoulder cosmesis plays an important role in patients' satisfaction of surgical outcomes. Up to now, only radiographic parameters were used to evaluate the shoulder balance in literatures; no corresponding cosmetic parameters have been developed to evaluate the cosmetic shoulder balance. Meanwhile, we often confronted that perfect radiographic shoulder balance was achieved, but the patients complained about the residual cosmetic deformity. This phenomenon implied that discrepancy may exist between radiographic shoulder balance and cosmetic shoulder balance. The present study was carried out to investigate the correlation between radiographic and clinical cosmetic shoulder balance in AIS patients with double thoracic curve. Thirty-four AIS patients were recruited for this study. All the patients had a double thoracic curve. Six cosmetic parameters--inner shoulder height (SHi), outer shoulder height (SHo), shoulder area index 1 (SAI1), shoulder area index 2 (SAI2), shoulder angle (alpha1) and axilla angle (alpha2) were developed and measured on the standing photographs. Also, seven radiographic parameters--T1 tilting (T1), first rib angle (FRA), clavicle angle (CA), coracoid process height (CPH), clavicle-rib cage intersection (CRCI), first rib-clavicle height (FRCH), trapezius length (TL) were measured on the standing posterior-anterior radiographs. Correlation analysis was made between cosmetic parameters and radiographic parameters. SHi was found to be significantly correlated with T1, FRA, CA, CPH, CRCI (P < 0.05), among which FRA had the highest correlation coefficient. SHo was found to be significantly correlated with T1, FRA, CA, CPH, CRCI, FRCH (P < 0.05), among which CRCI had the highest correlation coefficient. However, none of the correlation coefficient was greater than 0.8. The correlation coefficients between radiographic parameters and SAI1, SAI2, alpha1, alpha2 were also below 0.8 that were similar with SH. The results indicated that radiographic parameters could only partially reflect the shoulder cosmetic appearances. However, none of the existing parameters can accurately reflect the shoulder cosmetic appearance. As cosmesis is critical important to patients' satisfaction, spine surgeons should pay more attention to the cosmetic shoulder balance rather than radiographic shoulder balance.

Surgical treatment of main thoracic scoliosis with thoracoscopic anterior instrumentation. a five-year follow-up study

BACKGROUND

The surgical outcomes in patients with scoliosis at two years following anterior thoracoscopic spinal instrumentation and fusion have been reported. The purpose of this study was to evaluate the results at five years.

METHODS

A consecutive series of forty-one patients with major thoracic scoliosis treated with anterior thoracoscopic spinal instrumentation was evaluated at regular intervals. Prospectively collected data included patient demographics, radiographic measurements, clinical deformity measures, pulmonary function, an assessment of intervertebral fusion, and the scores on the Scoliosis Research Society (SRS-24) outcomes instrument. Perioperative and postoperative complications were recorded. Patient data for the preoperative, two-year, and five-year postoperative time points were compared. In addition, a univariate analysis compared selected two-year radiographic, pulmonary function, and SRS-24 data of the study cohort and those of the patients lost to follow-up.

RESULTS

Twenty-five (61%) of the original forty-one patients had five-year follow-up data and were included in the analysis. Between the two-year and five-year follow-up visits, no significant changes were observed with regard to the average percent correction of the major Cobb angle (56% +/- 11% and 52% +/- 14%, respectively), average total lung capacity as a percent of the predicted value (95% +/- 14% and 91% +/- 10%), and the average total SRS-24 score (4.2 +/- 0.4 and 4.1 +/- 0.7). Radiographic evaluation of intervertebral fusion at five years revealed convincing evidence of a fusion with remodeling and trabeculae present at 151 (97%) of the 155 instrumented motion segments. No postoperative infections or clinically relevant neurovascular complications were observed. Rod failure occurred in three patients, and three patients required a surgical revision with posterior spinal instrumentation and fusion.

CONCLUSIONS

Thoracoscopic anterior instrumentation for main thoracic idiopathic scoliosis results in five-year outcomes comparable with those reported previously for open anterior and posterior techniques. The radiographic findings, pulmonary function, and clinical measures remain stable between the two and five-year follow-up time points. Thoracoscopic instrumentation provides a viable alternative to treat spinal deformity; however, the risks of pseudarthrosis, hardware failure, and surgical revision should be considered along with the advantages of limited muscular dissection and improved scar appearance.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.