Changes in surface and radiographic deformity after Universal Spine System for right thoracic adolescent idiopathic scoliosis: is rib-hump reassertion a mechanical problem of the thoracic cage rather than an effect of relative anterior spinal overgrowth?

Changes in trunk appearance following surgical correction of adolescent idiopathic scoliosis

PURPOSE

To assess the postoperative appearance of the trunk in surgically treated scoliosis patients after a 2 year follow-up using reliable indices and compare the results with 6-month follow-up.

METHODS

Forty-six Adolescent Idiopathic Scoliosis (AIS) patients (female; preop mean age 14.4 ± 2.4 years) who underwent a posterior spinal fusion from 2009 to 2018 were included in this study. All had Lenke 1A thoracic curves, with surface topography taken preoperatively, 6 months and 2 years postoperatively. To assess spinal deformity, we measured the proximal thoracic, main thoracic and thoracolumbar/lumbar Cobb angles in the frontal plane from spinal X-rays and inclinometer angles in the thoracic and lumbar regions. To assess trunk deformity, Back Surface Rotation (BSR) and Trunk Lateral Shift (TLS) were computed along the trunk. We analysed the effect of age, height, weight, Cobb angle, length of follow-up, and surgical technique. We also compared correction rates (CRs) of the spinal and trunk measurements after 6 months and 2 years.

RESULTS

Good spinal correction was achieved, with Cobb angles decreasing in the whole cohort. CRs for TLS and BSR were positive (denoting improvement) for 76% and 48% of patients, respectively, after 2 years. Compared with 6 months, the mean TLS CR increased while there was no improvement for BSR on average. We found no significant association after 2 years between truncal index CRs and clinical variables (age, height, weight, preoperative Cobb angles) or surgical technique. However, there were significant correlations between the CRs of TLS and the main thoracic Cobb angle (r = 0.35), and between the CRs of BSR and thoracic inclinometer angle.

CONCLUSION

Although more than 55% of the TLS was corrected after 2 years of follow-up, the BSR remained stable over time and the persistence of rib hump on the back surface could be observed.

LEVEL OF EVIDENCE

III.

Why Is There Always a Remnant Rib Hump Deformity after Spinal Operations in Idiopathic Scoliosis: Aetiological Implications and Recognition of the Proper Rib Level for Costoplasty

The aim of this report is to review the literature dealing with the postoperative correction of rib hump (RH) after spinal operations for adolescent idiopathic scoliosis (AIS) and its aetiological implications of hump postoperative fate for IS. Recommendations related to RH deformity for the follow-up of younger asymmetric but not scoliotic children are provided, and the concept that clinical monitoring of the chest deformity is more important than merely an initially negative radiographic examination (curve less than 10°) is underlined. Additionally, guidelines are provided based on the segments T1-T12 rib index (RI) in the existing lateral preoperative radiographs for the optimal selection of the rib level for a successfully costoplasty. This review is based on the collected articles that used either the RI method, derived from the double rib contour sign (DRCS) at the lateral spinal radiographs, or alternative methods for the assessment of the RH deformity and presented the results of the operative treatment of the scoliotic spine on RH. A total of 19 relevant articles published from 1976 to 2022 were found in PubMed. Findings: All the above articles show that not only is the hump incompletely corrected, but it recurs and worsens during the follow-up and even more intensively in skeletally immature operated scoliosis children. Conclusions and Future Directions: Surgery straightens the spine, yet the RH is corrected approximately only as much as the spinal derotation. The only way to correct the RH more is with costoplasty, which, however, is not performed in most cases for many reasons. The key reason for this phenomenon is the fact that the RH deformity (RHD) is mainly due to the asymmetric development of the ribs and much less so due to the rotation of the vertebrae in the thoracic spine. Surgery on the spine cannot limit the asymmetry of the ribs or stop the mechanism that causes their asymmetrical growth. The results presented in all the reviewed articles support the important protagonistic role of RHD on scoliogenesis, which precedes the subsequent formed spinal deformity.

Morphological patterns of the rib cage and lung in the healthy and adolescent idiopathic scoliosis

The morphology of the rib cage affects both the biomechanics of the upper body's musculoskeletal structure and the respiratory mechanics. This becomes particularly important when evaluating skeletal deformities, as in adolescent idiopathic scoliosis (AIS). The aim of this study was to identify morphological characteristics of the rib cage in relation to the lung in patients with non‐deformed and scoliotic spines. Computed tomography data of 40 patients without any visible spinal abnormalities (healthy group) and 21 patients with AIS were obtained retrospectively. All bony structures as well as the right and left lung were reconstructed using image segmentation. Morphological parameters were calculated based on the distances between characteristic morphological landmarks. These parameters included the rib position, length, and area, the rib cage depth and width, and the rib inclination angle on either side, as well as the spinal height and length. Furthermore, we determined the left and right lung volumes, and the area of contact between the rib cage and lung. Differences between healthy and scoliotic spines were statistically analysed using the t‐test for unpaired data. The rib cage of the AIS group was significantly deformed in the dorso‐ventral and medio‐lateral directions. The anatomical proximity of the lung to the ribs was nearly symmetrical in the healthy group. By contrast, within the AIS group, the lung covered a significantly greater area on the left side of the rib cage at large thoracic deformities. Within the levels T1–T6, no significant difference in the rib length, depth to width relationship, or area was observed between the healthy and AIS groups. Inferior to the lung (T7–T12), these parameters exhibited greater variability. The ratio between the width of the rib cage at T6 and the thoracic spinal height (T1–T12) was significantly increased within the thoracic AIS group (1.1 ± 0.08) compared with the healthy group (1.0 ± 0.05). No statistical differences were found between the lung volumes among all the groups. While the rib cage was frequently strongly deformed in the AIS group, the lung and its surrounding ribs appeared to be normally developed. The observed rib hump in AIS appeared to be formed particularly by a more ventral position of the ribs on the concave side. Furthermore, the rib cage width to spinal height ratio suggested that the spinal height of the thoracic AIS‐spine is reduced. This indicates that the spine would gain its growth‐related height after correcting the spinal deformity. These are the important aspects to consider in the aetiology research and orthopaedic treatment of AIS.

Quantifying Anterior Chest Wall Deformity in Adolescent Idiopathic Scoliosis: Correlation With Other Deformity Measures and Effects of Anterior Thoracoscopic Scoliosis Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

This study investigated how anterior chest wall deformity is affected by thoracoscopic anterior scoliosis fusion (TASF) surgery in adolescent idiopathic scoliosis patients. We aimed to determine correlations pre- and postoperatively with other clinical and radiological scoliosis measures.

BACKGROUND DATA

Scoliosis surgery aims to halt progression of the deformity, and to reduce its severity. Currently, deformity correction is clinically measured in terms of Cobb angle and rib hump (RH); however, a significant cosmetic concern for patients is anterior chest wall deformity.

METHODS

Pre- and postoperative CT scans of 28 female, Lenke type 1 patients with a mean preoperative Cobb angle of 50.2° ± 7.1° were retrieved from the Research Group's surgical database. Using ImageJ, 3D reconstructions of the thorax were created. Two observers measured the anterior chest wall deformity as a chest wall angle (CWA) and posterior deformity as a posterior apical deformity angle (PDA). We investigated pre- to postoperative changes in CWA, PDA, RH, and Cobb angle as well as their interrelationship.

RESULTS

All deformity parameters (Cobb angle, RH, CWA, and PDA) showed statistically significant improvement post TASF. Correlation was found between RH and Cobb angle pre- and postoperatively, Cobb angle and CWA preoperatively and between postoperative change in Cobb angle and CWA. No relationship was found between CWA and RH or PDA.

CONCLUSIONS

Anterior chest wall deformity is independent from the posterior chest wall measures RH and PDA, indicating that the anterior chest wall deformity is not reflected in the posterior rib cage. The correlation between Cobb angle and CWA indicates that the deformity in the spine and the deformity in the ribs are related, and shows that the anterior chest wall deformity is improved post thoracoscopic anterior scoliosis fusion surgery as the lateral deviation of the spine is corrected.

LEVEL OF EVIDENCE

Level III.

Is vertebral rotation correction maintained after thoracoscopic anterior scoliosis surgery? A low-dose computed tomography study

Background

Axial vertebral rotation is a key characteristic of adolescent idiopathic scoliosis (AIS), and its reduction is one of the goals of corrective surgery. Recurrence of deformity after surgical correction may relate to rotation changes that occur in the anterior vertebral column after surgery, but whether any change occurs within the fused segment or in adjacent unfused levels following thoracoscopic anterior spinal fusion (TASF) is unknown. An analysis of measurements from an existing postoperative CT dataset was performed to investigate the occurrence of inter- and intra-vertebral rotation changes after TASF within and adjacent to the fused spinal segment and look for any relationships with the Cobb angle and rib hump in the two years after surgery.

Methods

39 Lenke Type 1 main thoracic patients underwent TASF for progressive AIS and low dose computed tomography scanning of the instrumented levels of the spine at 6 and 24 months after surgery. Vertebral rotation was measured at the superior and inferior endplates on true axial images for all vertebral levels in the fused segment plus one adjacent level cranially and caudally. Intra-observer variability for rotation measurements was assessed using 95% limits of agreement to detect significant changes in inter/intra-vertebral rotation.

Results

Significant local changes in inter- and intra-vertebral rotation were found to have occurred between 6 and 24 months after anterior surgical fusion within the fused spinal segment, albeit with no consistent pattern of location or direction within the instrumented fusion construct. No significant en-bloc movement of the entire fused spinal segment relative to the adjacent un-instrumented cranial and caudal intervertebral levels was found. No clear correlation was found between any vertebral rotation changes and Cobb angle or rib hump measures.

Conclusions

Localised inter- and intra-vertebral rotation occurs between 6 and 24 months after TASF, both within the instrumented spinal segments and in the adjacent un-instrumented levels of the adolescent spine. The lack of measurable en-bloc movement of the fused segment relative to the adjacent un-instrumented levels suggests that overall stability of the instrumented construct is achieved, however the vertebrae within the fusion mass continue to adapt and remodel, resulting in ongoing local anatomical and biomechanical changes in the adolescent spine.

Does an Internal Thoracoplasty Correct and Prevent a Reassertion of the Rib Cage Deformity After Spine Surgery for an Adolescent Idiopathic Thoracic Scoliosis Greater Than 70 Degrees

STUDY DESIGN

Prospective observational study.

OBJECTIVE

To evaluate the effect of internal thoracoplasty and anterior spine release combined with posterior spinal instrumentation in correcting and preventing a reoccurrence of the rib cage deformity in adolescent idiopathic thoracic scoliosis >70 degrees.

SUMMARY OF BACKGROUND DATA

The rib cage deformity rather than the lateral curvature of the spine is usually the major cosmetic deformity in severe adolescent idiopathic thoracic scoliosis. This can be difficult to treat and assess the effect of surgery.

METHODS

The Integrated Shape Imaging System was used to assess rib cage deformity before surgery and during follow-up for more than 2 years in 37 patients with an adolescent idiopathic thoracic scoliosis (Lenke 1) >70° (mean 81°) treated by internal thoracoplasty and anterior spine release combined with posterior spinal instrumentation using a hybrid construct.

RESULTS

The mean Cobb angle was reduced from 81° to 30° (63% correction). The rib cage deformity was improved in 30 patients (81%) because of a combination of both a reduction of the convex rib hump and an elevation of the concave rib depression. However, the effect on patients with an angle of thoracic inclination <16° was not as reliable. One year after surgery, additional improvement of the chest deformity had occurred in 9 patients. In none of the 37 patients was there any further progression of the rib cage deformity.

CONCLUSION

An internal thoracoplasty was effective in improving and/or stabilizing the rib cage deformity as well as achieving good correction of the scoliosis in patients with adolescent idiopathic thoracic scoliosis and severe deformity.

Changes in Trunk Appearance After Scoliosis Spinal Surgery and Their Relation to Changes in Spinal Measurements

STUDY DESIGN

Retrospective study of surgical outcome.

OBJECTIVES

To evaluate quantitatively the changes in trunk surface deformities after scoliosis spinal surgery in Lenke 1A adolescent idiopathic scoliosis (AIS) patients and to compare it with changes in spinal measurements.

SUMMARY OF BACKGROUND DATA

Most studies documenting scoliosis surgical outcome used either radiographs to evaluate changes in the spinal curve or questionnaires to assess patients health-related quality of life. Because improving trunk appearance is a major reason for patients and their parents to seek treatment, this study focuses on postoperative changes in trunk surface deformities. Recently, a novel approach to quantify trunk deformities in a reliable, automatic, and noninvasive way has been proposed.

METHODS

Forty-nine adolescents with Lenke 1A idiopathic scoliosis treated surgically were included. The back surface rotation and trunk lateral shift were computed on trunk surface acquisitions before and at least 6 months after surgery. We analyzed the effect of age, height, weight, curve severity, and flexibility before surgery, length of follow-up, and the surgical technique. For 25 patients with available three-dimensional (3D) spinal reconstructions, we compared changes in trunk deformities with changes in two-dimensional (2D) and 3D spinal measurements.

RESULTS

The mean correction rates for the back surface rotation and the trunk lateral shift are 18% and 50%, respectively. Only the surgical technique had a significant effect on the correction rate of the back surface rotation. Direct vertebral derotation and reduction by spine translation provide a better correction of the rib hump (22% and 31% respectively) than the classic rod rotation technique (8%). The reductions of the lumbar Cobb angle and the apical vertebrae transverse rotation explain, respectively, up to 17% and 16% the reduction of the back surface rotation.

CONCLUSIONS

Current surgical techniques perform well in realigning the trunk; however, the correction of the deformity in the transverse plane proves to be more challenging. More analysis on the positive effect of vertebral derotation on the rib hump correction is needed.

LEVEL OF EVIDENCE

III.

Quantitative ultrasound measurements of bone quality in female adolescents with idiopathic scoliosis compared to normal controls

OBJECTIVE

The aims of this study were to compare the speed-of-sound (SOS) between adolescent idiopathic scoliosis (AIS) patients and controls using quantitative ultrasound examination and to further analyze the relationship between the SOS and curve type, curve magnitude, maturation status and Risser's sign in AIS patients compared to controls.

METHODS

Seventy-eight female AIS patients and 58 healthy female controls 10 to 16 years of age were recruited to participate. Quantitative ultrasound measurements were performed at the non-dominant distal end of the radius. The standard method for estimating the SOS and z-score was used. Comparisons were made between the SOS values and z-score in AIS patients and age-matched Asian adolescents.

RESULTS

The SOS values of the patients were significantly lower than the controls (P < .01). The percentage of cases with low bone quality was 25% in the entire AIS sample. The prevalence of low bone quality in AIS patients was 20.5%. However, there were no correlations between the SOS and types of scoliosis (P > .05). The SOS values among different severity groups were significant, particularly between the 10° to 19° and 20° to 39° groups as well as between 10° to 19° and ≥40° groups. However, there was no significant correlation between the SOS and Cobb angles. Significant correlations were also found between the pre- and post-menarchy status in patients. There was a significant difference in the SOS values for different Rissers' signs (P < .05).

CONCLUSIONS

Compared to nonscoliotic controls, subjects with AIS had a generally lower SOS, indicating lower bone quality. The age, Risser's sign, or maturation status, may have an effect on the bone quality; however, the curve type and magnitude do not affect the bone quality. The results of this study indicate that slower bone maturation may affect the bone quality in adolescents with AIS.

Quantification of the spatial strain distribution of scoliosis using a thin-plate spline method

The objective of this study was to quantify the three-dimensional spatial strain distribution of a scoliotic spine by nonhomogeneous transformation without using a statistically averaged reference spine. The shape of the scoliotic spine was determined from computed tomography images from a female patient with adolescent idiopathic scoliosis. The shape of the scoliotic spine was enclosed in a rectangular grid, and symmetrized using a thin-plate spline method according to the node positions of the grid. The node positions of the grid were determined by numerical optimization to satisfy symmetry. The obtained symmetric spinal shape was enclosed within a new rectangular grid and distorted back to the original scoliotic shape using a thin-plate spline method. The distorted grid was compared to the rectangular grid that surrounded the symmetrical spine. Cobb's angle was reduced from 35° in the scoliotic spine to 7° in the symmetrized spine, and the scoliotic shape was almost fully symmetrized. The scoliotic spine showed a complex Green-Lagrange strain distribution in three dimensions. The vertical and transverse compressive/tensile strains in the frontal plane were consistent with the major scoliotic deformation. The compressive, tensile and shear strains on the convex side of the apical vertebra were opposite to those on the concave side. These results indicate that the proposed method can be used to quantify the three-dimensional spatial strain distribution of a scoliotic spine, and may be useful in quantifying the deformity of scoliosis.

Non invasive clinical assessment of trunk deformities associated with scoliosis

Besides the spinal deformity, scoliosis modifies notably the general appearance of the trunk resulting in trunk rotation, imbalance and asymmetries which constitutes patients' major concern. Existing classifications of scoliosis, based on the type of spinal curve as depicted on radiographs, are currently used to guide treatment strategies. Unfortunately, even though a perfect correction of the spinal curve is achieved, some trunk deformities remain, making patients dissatisfied with the treatment received. The purpose of this study is to identify possible shape patterns of trunk surface deformity associated with scoliosis. First, trunk surface is represented by a multivariate functional trunk shape descriptor based on 3D clinical measurements computed on cross sections of the trunk. Then, the classical formulation of hierarchical clustering is adapted to the case of multivariate functional data and applied to a set of 236 trunk surface 3D reconstructions. The highest internal validity is obtained when considering 11 clusters that explain up to 65% of the variance in our dataset. Our clustering result shows a concordance with the radiographic classification of spinal curves in 68% of the cases. As opposed to radiographic evaluation, the trunk descriptor is three-dimensional and its functional nature offers a compact and elegant description of not only the type, but also the severity and extent of the trunk surface deformity along the trunk length. In future work, new management strategies based on the resulting trunk shape patterns could be thought of in order to improve the esthetic outcome after treatment, and thus patients satisfaction.

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.

Comparison of compensatory curve spontaneous derotation after selective thoracic or lumbar fusions in adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective review of a multicenter prospectively collected series of adolescent idiopathic scoliosis (AIS) patients.

OBJECTIVE

To compare uninstrumented compensatory curve spontaneous derotation of the rib hump and lumbar prominence after selective lumbar or thoracic fusions in AIS.

SUMMARY OF BACKGROUND DATA

Coronal correction of the unfused minor curve after selective fusions in AIS has been well-documented previously. However, little has been reported regarding spontaneous correction in the axial plane of the unfused minor curve after selective AIS surgery.

METHODS

Patients with minimum 2-year follow-up after either a selective thoracic fusion (STF) (lowest instrumented vertebrae L2 or above), or a selective lumbar fusion (upper instrumented vertebrae T9 or below) for AIS, with an initial scoliometer value of >or=5 degrees in the minor curve were analyzed. Prospectively acquired preoperative and 2-year postoperative radiographic and scoliometer measurements of both the fused and unfused curves were compared using repeated measures and univariate analysis of variance. The data were checked for normality and equal variances, and the level of significance was set at P <or= 0.05.

RESULTS

In patients that underwent a STF (n = 83), the mean thoracic rib hump improved significantly from a preoperative value of 15 degrees +/- 5 degrees to 7 degrees +/- 4 degrees at the 2-year follow-up (P <or= 0.001). The mean lumbar prominence of the unfused curve also spontaneously improved significantly in this group of patients during the follow-up period from 9 degrees +/- 3 degrees to 4 degrees +/- 3 degrees (P <or= 0.001). In patients who underwent a selective lumbar fusion (n = 27), the mean lumbar prominence corrected significantly from a preoperative value of 11 degrees +/- 5 degrees , to a 2-year postoperative value of 3 degrees +/- 3 degrees (P <or= 0.001). The mean thoracic rib hump, however, only changed from 8 degrees +/- 3 degrees before surgery to 6 degrees +/- 3 degrees at the 2-year follow-up. This change was not found to be statistically significant (P = 0.14). The spontaneous lumbar prominence correction of 49% was significantly greater than the spontaneous thoracic rib hump correction of 26% (P = 0.04).

CONCLUSION

Axial plane rotational correction of the unfused minor curve in patients undergoing selective fusions does occur. Significant spontaneous correction of a thoracic rib hump after a selective lumbar fusion should not be anticipated, whereas an approximate 50% reduction in the lumbar prominence was the average after selective thoracic fusions.

Rate of complications in scoliosis surgery - a systematic review of the Pub Med literature

Background

Spinal fusion surgery is currently recommended when curve magnitude exceeds 40–45 degrees. Early attempts at spinal fusion surgery which were aimed to leave the patients with a mild residual deformity, failed to meet such expectations. These aims have since been revised to the more modest goals of preventing progression, restoring 'acceptability' of the clinical deformity and reducing curvature.

In view of the fact that there is no evidence that health related signs and symptoms of scoliosis can be altered by spinal fusion in the long-term, a clear medical indication for this treatment cannot be derived. Knowledge concerning the rate of complications of scoliosis surgery may enable us to establish a cost/benefit relation of this intervention and to improve the standard of the information and advice given to patients. It is also hoped that this study will help to answer questions in relation to the limiting choice between the risks of surgery and the "wait and see – observation only until surgery might be recommended", strategy widely used. The purpose of this review is to present the actual data available on the rate of complications in scoliosis surgery.

Materials and methods

Search strategy for identification of studies; Pub Med and the SOSORT scoliosis library, limited to English language and bibliographies of all reviewed articles. The search strategy included the terms; 'scoliosis'; 'rate of complications'; 'spine surgery'; 'scoliosis surgery'; 'spondylodesis'; 'spinal instrumentation' and 'spine fusion'.

Results

The electronic search carried out on the 1^st February 2008 with the key words "scoliosis", "surgery", "complications" revealed 2590 titles, which not necessarily attributed to our quest for the term "rate of complications". 287 titles were found when the term "rate of complications" was used as a key word. Rates of complication varied between 0 and 89% depending on the aetiology of the entity investigated. Long-term rates of complications have not yet been reported upon.

Conclusion

Scoliosis surgery has a varying but high rate of complications. A medical indication for this treatment cannot be established in view of the lack of evidence. The rate of complications may even be higher than reported. Long-term risks of scoliosis surgery have not yet been reported upon in research. Mandatory reporting for all spinal implants in a standardized way using a spreadsheet list of all recognised complications to reveal a 2-year, 5-year, 10-year and 20-year rate of complications should be established. Trials with untreated control groups in the field of scoliosis raise ethical issues, as the control group could be exposed to the risks of undergoing such surgery.

Is there a body of evidence for the treatment of patients with Adolescent Idiopathic Scoliosis (AIS)?

Historically, the treatment options for AIS, the most common form of scoliosis are; exercises; in-patient rehabilitation; braces and surgery. While there is evidence in the form of prospective controlled studies that Scoliosis Intensive Rehabilitation (SIR) and braces can alter the natural history of the condition, there is no prospective controlled study comparing the natural history with surgical treatment.One aim of the Scoliosis Society (SOSORT) should be; to help develop a body of research regarding the outcomes of conservative and operative treatment as well, and to highlight the problems of treatment indications in patients with AIS and other spinal deformities. Another aim is to help to improve the safety of patients who have surgery. By producing evidence-based information that can be used to develop guidelines that could aid both professionals and patients in making decisions about surgical and conservative options.Although 'Scoliosis' is the official journal of the SOSORT and is the main forum for experts in the field of conservative management of patients with spinal deformities, there needs to be more wide spread attempt to develop a fuller body of evidence focussing on spine surgery as well.

Adolescent Idiopathic Scoliosis - case report of a patient with clinical deterioration after surgery

BACKGROUND

Although there is no evidence that the long-term effects of scoliosis surgery are superior to the long-term effects of Adolescent Idiopathic Scoliosis (AIS) itself, patients can fear the consequences of not under going this surgery due to incorrect or insufficient information. The main indication for surgical treatment in patients with AIS, is cosmetic. However spinal surgery may, along with other negative side effects, actually cause postoperative clinical deterioration. This complication of surgery has not yet been described in international literature.

CASE PRESENTATION

A 15-year old female patient originally presenting with a well-compensated double curve pattern scoliosis. The patient was advised to undergo surgery due to the long-term negative impact of signs and symptoms of scoliosis upon her health. The patient agreed to surgery, which was performed in one of Germanys leading centres for spinal surgery. The thoracolumbar curve was corrected and fused, while the thoracic curve, clearly showing wedged vertebrae, defined as structural scoliosis, remained untreated.This operation left the patient with an unbalanced appearance, with radiological and clinical imbalance to the right. The clinical appearance of the patient though clearly deteriorated post-surgery. Furthermore, the wedged disc space below the fusion area indicates future problems with possible destabilisation accompanied probably by low back pain.

CONCLUSION

Scoliosis surgery for patients with AIS is mainly indicated for cosmetic or psychological reasons. Therefore the treatment leading to the best possible clinical appearance and balance has to be chosen. Patients should be informed that surgery will not necessarily improve their health status. Clinical deterioration after surgery may occur, and such information is crucial for an adequate informed consent.

Surgical correction of spinal deformities after solid organ transplantation in childhood

A review of the current literature reveals no systematic analyses of the results of surgical correction of spinal deformity after pediatric organ transplantation. We therefore evaluated clinical and radiographic outcomes of spinal deformity correction after solid organ transplantation in childhood and adolescence. All 211 cases of heart, liver, and kidney transplantations performed in children in our country were reviewed. Six patients had undergone surgical correction of spinal deformity at a mean age 14.6 (range 12-17) years. Clinical data of the patients were evaluated. Radiographs of the whole spine were taken preoperatively, immediately after, at 2-year, and final follow-up visits. The Scoliosis Research Society (SRS) questionnaire was completed and a physical examination was performed at the final follow-up visit. The mean follow-up after spinal surgery was 4.9 years (range 2-7.6 years). Four patients developed scoliosis after organ transplantation without any evidence of scoliosis prior to organ transplantation. One patient with congenital scoliosis was operated on after kidney transplantation. One boy had osteoporosis and severe local kyphosis due to vertebral compression fractures. Four patients underwent anterior and posterior surgery, two posterior only. The mean preoperative Cobb angle of the thoracic curve was 54 degrees (range 42-69 degrees) in the patients with scoliosis. The postoperative values were 30 degrees (26-38 degrees) immediately after instrumentation and 39 degrees (34-42 degrees) at the final follow-up visit. The patient with vertebral compression fractures and progressive kyphosis had 70 degrees curve before surgery, 23 degrees immediately after the operation, and 60 degrees at the final check up. The mean total score on the SRS questionnaire was 95.5 (range 90-101). There is a relatively high incidence (2.8%) of spinal deformities needing operative treatment after solid organ transplantation. Possible etiologies for spinal deformities are growth disturbance and muscle weakness due to the basic disease. The other important factors are related to immunosuppressive medication, especially glucocorticoids needed after transplantation. Primary correction of these deformities was satisfactory, but during follow-up, a certain amount of recurrence of the curves was evident. Poor bone quality may explain some of the loss of correction.

Does gender affect outcome of surgery in adolescent idiopathic scoliosis?

STUDY DESIGN

A retrospective follow-up study comparing 2 matched groups.

OBJECTIVE

To compare long-term results of operative treatment of adolescent idiopathic scoliosis (AIS) between males and females matched for age, curve magnitude and type, and the instrumentation used.

SUMMARY OF BACKGROUND DATA

It has been suggested that in AIS, the spine is more rigid in males than in females, because brace treatment fails to halt progression of the curves in males. However, there are no studies comparing the results of surgical treatment of AIS between males and females.

METHODS

Thirty male and female pairs were matched for age (+/-1 year), major curve magnitude (+/-5 degrees), curve type according to the King classification, and the instrumentation used (Harrington in 11 pairs, Cotrel-Dubousset in 9 pairs, and Universal Spine System in 10 pairs). The mean age at the time of operation was 16.2 +/- 2.6 years for the males and 15.5 +/- 2.3 years for the females. The mean follow-up times were 14.3 years (range 6.7-23.0 years) and 14.1 year (range 6.4-23.7 years), respectively. Radiographs were obtained presurgery and after surgery, at the 2-year follow-up assessment, and at the final follow-up visit. In addition, a physical examination was performed, and the Scoliosis Research Society (SRS) questionnaire was completed. Spine mobility and nondynamometric trunk strength were measured at the final follow-up visit.

RESULTS

Before surgery, the mean Cobb angle of the thoracic curve was 55 degrees (range 42-83 degrees) in the males and 56 degrees (range 43-80 degrees) in the females. In bending radiographs, the major curve reduced significantly more in females than in males (P = 0.027). The mean angles of the thoracic and lumbar curves were similar at all follow-up visits. The final correction of the thoracic curves was 30% (range -19-65%) in the males and 33% (range -7-71%) in the females (not significant). No significant difference was observed in thoracic kyphosis or lumbar lordosis between the study groups at the final follow-up. The total SRS questionnaire score averaged 96 (range 66-113) in the males and 95 (range 75-108) in the females. None of the males and 2 of the females reported back pain often or very often in the questionnaire. Nondynamometric trunk strength measurements corresponded with reference values, on average, and were similar in both groups. Abnormal trunk side bending tended to be more common in the males than in the females (43% vs. 23%, P = 0.10, not significant).

CONCLUSIONS

Curves in males appear to be more rigid than in females with AIS. However, posterior surgery for AIS provides similar short and long-term results in males and females.

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

STUDY DESIGN

A retrospective comparison of the clinical, radiologic, and functional results of Cotrell-Dubousset (CD) and Universal Spine System (USS) instrumentation for adolescent idiopathic scoliosis (AIS).

OBJECTIVES

To establish whether there are any differences in outcome between the 2 instrumentation systems.

SUMMARY OF BACKGROUND DATA

CD is the first complex posterior double rod instrumentation system to provide multiple hook fixation. USS instrumentation permits the use of rod translation instead of rod rotation, the option to secure pedicle hooks with fixation screws, and the option to use transpedicular screws in the lower thoracic and lumbar spine. Midterm and long-term results of USS instrumentation are lacking.

METHODS

Fifty-seven (mean age, 28 years at follow up) patients treated with CD instrumentation and 55 (mean age, 23 years at follow up) patients treated with USS instrumentation for AIS participated in the study. The average follow-up rate was 80% and time 13.0 years for the CD group, and 95% and 7.8 years for the USS group. Radiographs were obtained before surgery, at 2-year follow up, and at final follow up. Additionally, a physical examination was performed by 2 independent observers, and the Scoliosis Research Society (SRS) questionnaire was completed; spinal mobility and nondynamometric trunk strength were measured at the final follow-up visit. RESULTS.: The mean Cobb angle of the instrumented thoracic curve was before surgery 55 degrees (range, 36-83 degrees for the CD and 52 degrees (range, 35-85 degrees) for the USS group. The mean number of instrumented vertebrae was 9.9 (range, 7-12) in the CD and 9.8 (range, 6-12) in the USS group. At final follow up, the mean angles were 32 degrees (range, 13-63 degrees) for the CD group and 29 degrees (range, 9-63 degrees) for the USS group (not significant). No significant difference was observed in thoracic kyphosis or lumbar lordosis between the study groups at final follow up. In the SRS questionnaire, the total score averaged 97 for the CD and 101 for the USS groups, respectively. In the questionnaire, 6 (11%) patients in the CD group, but none in the USS group, reported having low back pain often or very often at rest. No correlation was found between the Cobb angle of the thoracic or lumbar curves at follow up and the total score or back pain indexes of this questionnaire. Nondynamometric trunk strength measurements corresponded with age- and sex-adjusted reference values, on average, but patients in the CD group performed significantly better in the squatting test (P = 0.021) and patients in the USS group performed better in trunk side bending (P = 0.004). Complications were recorded in 15 (26%) patients in the CD and in 13 (24%) patients in the USS group (not significant).

CONCLUSIONS

The midterm radiologic and functional outcomes were quite similar in both groups as were the SRS scores. The patients performed, on average, as well as did the reference population in nondynamometric trunk strength measurements. Intraoperative and late complications were similar in both groups.

Safety and efficacy of Isola instrumentation and arthrodesis for adolescent idiopathic scoliosis: two- to 12-year follow-up

STUDY DESIGN

Retrospective case series including patient outcome assessment.

OBJECTIVE

To study the safety and efficacy of Isola instrumentation in comparison with similar series.

SUMMARY OF BACKGROUND DATA

Both the technique and technology used in the surgical treatment of adolescent idiopathic scoliosis continue to evolve, the common theme since the 1980s being provision of instrumentation stable and strong enough to eliminate the need for postoperative immobilization. The purpose of this study is to determine the safety and efficacy of a system deliberately integrating hook, wire, and screw anchors to deliver torsional and countertorsional corrective loads.

METHODS

A total of 185 consecutive patients, index patient included, were treated by posterior instrumentation and arthrodesis from January 1989 through December 2000. Safety was studied by complications, and reoperation type and occurrence. Effectiveness was studied by deformity correction and health-related quality of life questionnaire response. Variables affecting effectiveness were sought. A total of 179 patients (97%) had outcome assessment at an average of 6 years postoperative, and 176 had radiographic evaluation at an average of 5 years postoperative.

RESULTS

There were no deaths, spinal cord or nerve root problems, or acute posterior wound infections. Proven pseudarthrosis occurred in 4 patients (2.2%) and delayed deep wound infection in 2 patients (1.1%). The implant-related reoperation rate was 8% and was necessary more often in the first quarter of the series (17% vs. 4.6%, P = 0.0062). The largest Cobb angle averaged 62 degrees preoperative and 23 degrees at latest follow-up, 63% correction. The largest angle of trunk inclination averaged 16.7 degrees before surgery and 9.9 degrees at latest follow-up, a 39% correction (P < 0.0001). Eighty-eight percent of patients were satisfied or very satisfied with the outcome. The principal problems identified were the need for a stronger transverse connector, stable end-instrumented vertebrae foundations, and convex thoracic anchorage.

CONCLUSIONS

Isola instrumentation seems to be at least as safe and effective as other instrumentations being used for the surgical treatment of adolescent idiopathic scoliosis.

Maintenance of trunk deformity correction following posterior instrumentation and arthrodesis for idiopathic scoliosis

STUDY DESIGN

This is a retrospective observational case series.

OBJECTIVES

To determine whether or not trunk deformity correction is achieved and maintained using the surgical techniques described.

SUMMARY OF BACKGROUND DATA

Transverse plane trunk deformity correction and correction maintenance have been questioned.

METHODS

The study group of 44 patients (40 female, 4 male) had a mean age of 16.1 years (range 10-38 years). Thirty-three had thoracic and 11 had a double curve pattern with a mean largest preoperative curve of 65 degrees. All had preoperative and follow-up at a median of 25 months (range 20-69 months); surface topography exposures quantified for both the coronal plane, as determined by the Posterior Trunk Symmetry Index, and transverse plane, as determined by the Suzuki Hump Sum, asymmetry. Thirty-four also had early postoperative studies. Change following surgery was determined by the signed rank test, with P < 0.01 being significant.

RESULTS

Preoperative to latest follow-up largest Cobb angles had improved from a mean of 65 degrees to 23 degrees (65%, P < 0.0001), Posterior Trunk Symmetry Index from 55 to 20 (64%) (P < 0.0001), and Suzuki Hump Sum from 20 to 12 (40%) (P < 0.0001). Posterior Trunk Symmetry Index improved during the follow-up from 26 to 20 (23%) (P = 0.007). Neither Cobb nor Suzuki Hump Sum further improved or deteriorated during follow-up.

CONCLUSION

These findings validate the concepts of torsional posterior spinal instrumentation and wide-thick arthrodesis to provide significant and lasting coronal and transverse plane trunk deformity correction.

Patient and parental perception of adolescent idiopathic scoliosis before and after surgery in comparison with surface and radiographic measurements

STUDY DESIGN

This prospective 2-year follow-up study evaluated patients treated surgically for adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To report parents' perception, patients' perception, and pain and disability before and after surgery and to examine their relationship to anthropometric, back surface, and radiographic measurements.

SUMMARY OF BACKGROUND DATA

No longitudinal studies have examined these factors and their interrelationships.

METHODS

Between 1995 and 1999, 39 AIS patients treated by anterior or posterior USS (Universal Spine System, Stratec, Oberdorf, Switzerland) instrumentation had complete prospective questionnaire, back surface, and radiographic appraisal.

RESULTS

The preoperative Visual Analogue Score (VAS) for pain-predominantly mild backache-was 24 mm (range, 0-78 mm), and the Oswestry Disability Index (ODI) score was 9.2% (0-44.4%). Patients and parents wanted surgery to correct spinal curvature, stop curve progression, and correct the rib-hump (thoracic) and hip and waist asymmetry (thoracolumbar curves). The maximum angle of trunk inclination correlated with VAS and with short-form McGill Pain Questionnaire scores for thoracic curves (P = 0.005, Spearman rank correlation coefficient). Apical vertebral translation correlated with short-form McGill scores and ODI for thoracolumbar curves (P < 0.006, Spearman rank correlation coefficient). Parents rated scoliosis problems more severely than did their children (P < 0.0001, repeated measures of multivariate analysis of variants). There was no change in body image, VAS, ODI, or short-form McGill scores by 2 years' follow-up. Parents and patients perceived scoliosis problems to be less by 2 years' follow-up (P < 0.0005, Wilcoxon matched-pairs signed ranks test). The preoperative surface asymmetry score correlated with the patients' grading of their rib-hump (P = 0.007).

CONCLUSIONS

Back pain incidence was higher than reported for healthy adolescents. Oswestry Disability Index was within normal adult limits. Pain varied by curve type, related to the maximum angle of trunk inclination and the maximum apical vertebral translation. After surgery, back pain and ODI were unchanged, but concerns regarding scoliosis were reduced.