Video-assisted anterior thoracoscopic spinal fusion versus posterior spinal fusion: a comparative study utilizing the SRS-22 outcome instrument

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.

Early operative morbidity in 184 cases of anterior vertebral body tethering

Fusion is the current standard of care for AIS. Anterior vertebral body tethering (AVBT) is a motion-sparing alternative gaining interest. As a novel procedure, there is a paucity of literature on safety. Here, we report 90-day complication rates in 184 patients who underwent AVBT by a single surgeon. Patients were retrospectively reviewed. Approaches included 71 thoracic, 45 thoracolumbar, 68 double. Major complications were those requiring readmittance or reoperation, prolonged use of invasive materials such as chest tubes, or resulted in spinal cord or nerve root injury. Minor complications resolved without invasive intervention. Mean operative time and blood loss were 186.5 ± 60.3 min and 167.2 ± 105.0 ml, respectively. No patient required allogenic blood transfusion. 6 patients experienced major (3.3%), and 6 had minor complications (3.3%). Major complications included 3 chylothoracies, 2 hemothoracies, and 1 lumbar radiculopathy secondary to screw placement requiring re-operation. Minor complications included 1 patient with respiratory distress requiring supplementary oxygen, 1 superficial wound infection, 2 cases of prolonged nausea, and 1 Raynaud phenomenon. In 184 patients who underwent AVBT for AIS, major and minor complication rates were both 3.3%.

Sinister! The high pre-op left shoulder is less likely to be radiographically balanced at 2 years post-op

PURPOSE

AIS patients consider shoulder balance an important cosmetic outcome after surgery. We examined the impact of preoperative left shoulder elevation (LSE) and choice of upper instrumented vertebra (UIV) on postoperative shoulder imbalance (PostSI).

METHODS

This was a retrospective cohort study utilizing a prospective AIS database. Patients had Lenke type 1-4 curves and preoperative shoulder height ≥ 1.0 cm. Patients with preoperative LSE and right shoulder elevation (RSE) were compared. Shoulder height difference < 1 cm was considered 'mild', 1-2 cm was 'moderate', and ≥ 2.0 cm was 'severe'.

RESULTS

407 patients had ≥ 1.0 cm imbalance preoperatively, with 88 (21.6%) LSE. There were no differences in gender (p = 0.855) or age (p = 0.477). Patients with LSE more frequently had Lenke type 2 curves (43.2% vs 16.3%, p < 0.001), while preoperative RSE averaged 1.9 ± 0.9 cm versus 1.6 ± 0.5 cm for LSE (p < 0.001). Those with LSE more often had severe PostSI at 2 years (30.7% vs 5.0%, p < 0.001), and only 26.1% of patients with severe preoperative LSE corrected to mild. In contrast, most patients with RSE had mild PostSI regardless of initial imbalance. When examining only LSE patients, there was no difference in preoperative SH by final UIV (p = 0.101). Further, UIV choice did not impact the proportion of severely unbalanced patients postoperatively (p = 0.446). A PTC > 34.5° was predictive of PostSI ≥ 2.0 cm for patients with preoperative LSE.

CONCLUSION

AIS patients with preoperative LSE are less likely to achieve level shoulders postoperatively. Choice of higher UIV did not affect postoperative shoulder imbalance in this cohort. A PTC > 34.5° was predictive of severe PostSI in patients with preoperative LSE.

LEVEL OF EVIDENCE

II.

Thoracoscopic Anterior Instrumentation and Fusion as a Treatment for Adolescent Idiopathic Scoliosis: A Systematic Review of the Literature

STUDY DESIGN

A systematic review and meta-analysis on thoracoscopic anterior instrumentation and fusion as a treatment for adolescent idiopathic scoliosis (AIS).

OBJECTIVE

The goal of this study is to determine the current status of thoracoscopic instrumentation and fusion as a treatment for AIS.

SUMMARY OF BACKGROUND DATA

Traditional surgical techniques for AIS have been open anterior thoracotomy with instrumentation and posterior spinal fusion and instrumentation. With the growing clinical interest in growth modulation surgeries, such as vertebral body tethering, there is a resurgence of interest in a thoracoscopic technique.

METHODS

The most commonly used medical databases (PubMed, Medline, EMBASE, CINAHL, and the Cochrane library) were searched up to November 2016 using the search terms VATS, thoracoscopic scoliosis, and thoracoscopic scoliosis instrumentation.

RESULTS

Thirteen studies met the strict inclusion criteria. Five hundred thirty patients were reported: 81.7% females, with the majority diagnosed as AIS. The mean operative time was 371.5 minutes, mean blood loss of 502.85 mL, and mean hospital stay of 5.9 days. Mean preoperative curve magnitude was 52.9°; postoperative curve magnitude was 17.9°, with a correction of 62.7%. Number of levels instrumented was 6.3, pulmonary function tests returned to preoperative values by 2 years postoperation, and the complication rate was 21.3%. Compared to thoracotomy, VATS had similar complication rates, blood loss, operation theater time, curve correction, and number of fused levels. Compared to posterior fusion, VATS has higher complication rates and operation theater time. Blood loss and percentage correction were similar. VATS had a smaller number of fused segments.

CONCLUSIONS

Advantages include less invasive, excellent curve correction, few levels fused, good satisfaction, and no long-term effect on pulmonary function. Drawbacks are increased operative time and incidence of pulmonary complications. With appropriate surgeon training and careful patient selection, this technique offers an acceptable alternative to the more traditional procedures.

LEVEL OF EVIDENCE

Level II.

Anterior or posterior surgery for right thoracic adolescent idiopathic scoliosis (AIS)? A prospective cohorts' comparison using radiologic and functional outcomes

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Prospectively compare patient-reported as well as clinical and radiologic outcomes after anterior or posterior surgery for right thoracic adolescent idiopathic scoliosis (AIS) in a single center by the same surgeons.

SUMMARY OF BACKGROUND DATA

Anterior and posterior spinal instrumentation and arthrodesis are both well-established treatments of thoracic AIS. The majority of studies comparing the 2 approaches have focused on radiographic outcomes. There remains a paucity of prospectively gathered patient-reported outcomes comparing surgical approaches.

METHODS

Forty-two consecutive patients with right thoracic AIS were treated in a single center by one of 2 surgeons with either anterior (n=18) or posterior (n=24) approaches and followed up for over 2 years. Radiographic, clinical, and patient-reported outcomes of the Modified Scoliosis Research Society Outcome Instrument were gathered and analyzed by an independent surgeon.

RESULTS

Patients reported significant improvements in all areas of the Modified Scoliosis Research Society Outcome Instrument, especially pain and self-image domains. There were no significant differences in the degree of improvement in any domains between the groups. Posterior and anterior surgery corrected rib hump by 53% and 61%, respectively (P=0.4). The Main thoracic curve Cobb angle was corrected from 69 to 26 degrees (62%) by posterior surgery and 61 to 23 degrees (64%) by anterior surgery (P=0.6). Posterior surgery significantly reduced kyphosis and lumbosacral lordosis. Anterior surgery had no overall affect of sagittal alignment but seemed able to correct those hypokyphotic preoperatively. Complications differed and were largely approach-related--intrathoracic in anterior and wound-related in posterior surgery.

CONCLUSIONS

Patients with right thoracic AIS of differing curve types but otherwise similar preoperatively demonstrated that anterior and posterior surgery are largely equivalent. Patient-reported outcomes are improved similarly by either approach. Both offer excellent radiographic and trunk deformity correction. Differences in the effect of sagittal alignment, operative time, and complications should be considered when selecting approach.

[Current status of thoracoscopic surgery for thoracic and lumbar spine. Part 2: treatment of the thoracic disc hernia, spinal deformities, spinal tumors, infections and miscellaneous]

INTRODUCTION

Thoracoscopic surgery or video-assisted thoracic surgery (VATS) of the thoracic and lumbar spine has evolved greatly since it appeared less than 20 years ago. It is currently used in a large number of processes and injuries. The aim of this article, in its two parts, is to review the current status of VATS of the thoracic and lumbar spine in its entire spectrum.

DEVELOPMENT

After reviewing the current literature, we developed each of the large groups of indications where VATS takes place, one by one. This second part reviews and discusses the management, treatment and specific thoracoscopic technique in thoracic disc herniation, spinal deformities, tumour pathology, infections of the spine and other possible indications for VATS.

CONCLUSIONS

Thoracoscopic surgery is in many cases an alternative to conventional open surgery. The transdiaphragmatic approach has made endoscopic treatment of many thoracolumbar junction processes possible, thus widening the spectrum of therapeutic indications. These include the treatment of spinal deformities, spinal tumours, infections and other pathological processes, as well as the reconstruction of injured spinal segments and decompression of the spinal canal if lesion placement is favourable to antero-lateral approach. Good clinical results of thoracoscopic surgery are supported by growing experience reflected in a large number of articles. The degree of complications in thoracoscopic surgery is comparable to open surgery, with benefits in regard to morbidity of the approach and subsequent patient recovery.

What is the effect of surgery on the quality of life of the adolescent with adolescent idiopathic scoliosis? A review and statistical analysis of the literature

STUDY DESIGN

Review and statistical analysis of studies evaluating the effect of surgery on the health-related quality of life of adolescents with adolescent idiopathic scoliosis, using Scoliosis Research Society (SRS) outcomes.

OBJECTIVE

Apply published minimum clinical important differences (MCID) values for the SRS22r questionnaire to the literature to identify what areas of health-related quality of life are consistently affected by surgery and whether changes are clinically meaningful.

SUMMARY OF BACKGROUND DATA

The interpretation of published studies using the SRS outcomes has been limited by the lack of MCID values for the questionnaire domains. The recent publication of these data allows the clinical importance of any changes in these studies to be examined for the first time.

METHODS

A literature search was undertaken to locate suitable studies that were then analyzed. Statistically significant differences from baseline to 2 years postoperatively were ascertained by narratively reporting the analyses within included studies. When possible, clinically significant changes were assessed using 95% confidence intervals for the change in mean domain score. If the lower bound of the confidence intervals for the change exceeded the MCID for that domain, the change was considered clinically significant.

RESULTS

The numbers of cohorts available for the different analyses varied (5-16). Eighty-one percent and 94% of included cohorts experienced statistically significant improvements in pain and self-image domains. In terms of clinical significance, it was only self-image that regularly improved by more than MCID, doing so in 4 of 5 included cohorts (80%) compared with 1 of 12 cohorts (8%) for pain. No clinically relevant changes occurred in mental health or activity domains.

CONCLUSION

Evidence suggests that surgery can lead to clinically important improvement in patient self-image. Surgeons and patients should be aware of the limited evidence for improvements in domains other than self-image after surgery. Surgical decision-making will also be influenced by the natural history of adolescent idiopathic scoliosis.

Comparison of untreated adolescent idiopathic scoliosis with normal controls: a review and statistical analysis of the literature

STUDY DESIGN

Review and statistical analysis of studies evaluating health-related quality of life (HRQOL) in adolescents with untreated adolescent idiopathic scoliosis (AIS) using Scoliosis Research Society (SRS) outcomes.

OBJECTIVE

To apply normative values and minimum clinical important differences for the SRS-22r to the literature. Identify whether the HRQOL of adolescents with untreated AIS differs from unaffected peers and whether any differences are clinically relevant.

SUMMARY OF BACKGROUND DATA

The effect of untreated AIS on adolescent HRQOL is uncertain. The lack of published normative values and minimum clinical important difference for the SRS-22r has so far hindered our interpretation of previous studies. The publication of this background data allows these studies to be re-examined.

METHODS

Using suitable inclusion criteria, a literature search identified studies examining HRQOL in untreated adolescents with AIS. Each cohort was analyzed individually. Statistically significant differences were identified by using 95% confidence intervals for the difference in SRS-22r domain mean scores between the cohorts with AIS and the published data for unaffected adolescents. If the lower bound of the confidence interval was greater than the minimum clinical important difference, the difference was considered clinically significant.

RESULTS

Of the 21 included patient cohorts, 81% reported statistically worse pain than those unaffected. Yet in only 5% of cohorts was this difference clinically important. Of the 11 cohorts included examining patient self-image, 91% reported statistically worse scores than those unaffected. In 73% of cohorts this difference was clinically significant. Affected cohorts tended to score well in function/activity and mental health domains and differences from those unaffected rarely reached clinically significant values.

CONCLUSION

Pain and self-image tend to be statistically lower among cohorts with AIS than those unaffected. The literature to date suggests that it is only self-image which consistently differs clinically. This should be considered when assessing the possible benefits of surgery.

Case report: Curetting osteoid osteoma of the spine using combined video-assisted thoracoscopic surgery and navigation

BACKGROUND

A spinal osteoid osteoma is a rare benign tumor. The usual treatment involves complete curettage including the nidus. In the thoracic spine, conventional open surgical treatment usually carries relatively high surgical risks because of the close anatomic relationship to the spinal cord, nerve roots, and thoracic vessels, and pulmonary complications and postoperative pain.

CASE REPORT

We report the case of a 16-year-old girl with a symptomatic osteoid osteoma at the T9 level whose lesion was currettaged using video-assisted thoracoscopic surgery (VATS) guided by a navigation system (VATS-NAV). There were no complications and the patient had immediate relief of the characteristic pain after surgery and was asymptomatic at 5 months' followup.

LITERATURE REVIEW

Progressive advances in the technology of spinal surgery have evolved to offer greater safety and less morbidity for patients. The advent of minimally invasive surgery has expanded the indications for VATS for anterior spinal disorders. Spinal navigation systems have become useful tools allowing localization and excision of the nidus of osteoid osteomas with minimal bone resection and without radiation exposure.

CLINICAL RELEVANCE

The VATS-NAV combination in our patient allowed accurate localization and guidance for complete excision of a spinal osteoid osteoma through a minimally invasive approach without compromising spinal stability.

Short segment bone-on-bone instrumentation for adolescent idiopathic scoliosis: a mean follow-up of six years

STUDY DESIGN

Prospective case series.

OBJECTIVE

To evaluate the clinical and radiologic outcomes of short segment anterior scoliosis surgery with bone-on-bone apposition using a dual screw, dual rod system.

SUMMARY OF BACKGROUND DATA

Posterior segmental fixation for correction of AIS involves instrumentation of all the vertebrae included in the major curve. Our short segment anterior technique produces similar results by fusion of fewer levels.

METHODS

Forty-five patients operated between 1996 and 2004. Twenty-eight thoracic (Lenke 1) and 17 thoracolumbar (Lenke 5). The mean age was 19 years, 87% were females, and the mean follow-up was 72 months (range 28-121 months). We operated on curves less than 85° with "total discectomy," bone-on-bone apposition, and dual-screw, dual-rod fixation.

RESULTS

A mean of five vertebrae (four discs) were instrumented, with a mean operative time of 360 minutes, blood loss of 877 mL and a hospital stay of 9.1 day. Lenke 1. The main preop thoracic curve was 52.5°, final postop curve 27.9°, by fusing five vertebrae, four discs. A spontaneous improvement of 47.5% of the lumbar compensatory curve was seen. The lower tilt angle corrected from 20.9° to 11°. Lenke 5. The preoperative thoracolumbar major curve corrected from 50.5° to 18.3° (final) with fusion of four vertebrae, three discs. A spontaneous improvement of 37.4% occurred in the thoracic compensatory curve. The preop tilt angle improved from 27.7° to 8.3°.The sagittal and coronal balance was restored in all the patients. There were no neurologic, vascular, pulmonary, or implant-related complications. Union occurred within 3 months. All the patients returned to an unrestricted lifestyle within 4 months.

CONCLUSION

We report good results after surgical correction using our short segment bone-on-bone technique. Improvements were noted and maintained, over a 6-year period.

Maximal pulmonary recovery after spinal fusion for adolescent idiopathic scoliosis: how do anterior approaches compare?

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVE

To compare the relative rates of pulmonary recovery and maximal pulmonary function with surgical approach.

SUMMARY OF BACKGROUND DATA

Anterior versus posterior spinal fusion (ASF, PSF) for the treatment of adolescent idiopathic scoliosis (AIS) has been debated. Although procedures that violate the chest wall may compromise pulmonary function, lung function continues to improve after surgery at variable rates depending upon surgical approach.

METHODS

We reviewed the medical records from one hundred fifty nine AIS patients (age 15.6±2.2; 113 women; 46 men) treated with spinal fusion from 2003 to 2007 by a single surgeon. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and radiographic measurements were evaluated before surgery and at 1, 3, 6, 12, and 24-months follow-up on average. Four surgical groups were compared: PSF, ASF (open thoracoabdominal approach for thoracolumbar curvature), video-assisted thoracoscopic surgical release with instrumentation (VATS-I), and VATS with PSF. FEV1 and FVC were fitted to model to evaluate the immediate postoperative pulmonary function (Yo), maximal recovery (Plateau), and rate (K) of pulmonary improvement.

RESULTS

Patients in each surgical subgroup were as follows: PSF (Lenke 1: n=50, Lenke 2,3: n=20), ASF (Lenke 5, n=35), VATS-I (Lenke 1=31, Lenke 3=1), and VATS+PSF (Lenke1: n=9, Lenke 2-6: n=13). Early postoperative pulmonary function was higher with ASF and PSF as compared to both VATS groups (P<0.05). Comparing all curve types, VATS-I showed a small decline of absolute FEV1 compared to PSF at 2-years follow-up. Comparing thoracic curves, however, no differences in FEV1 or FVC were noted at 6 to 12 months until 2-years follow-up. The rate of recovery (K) was equivalent for all surgical approaches and curve types.

CONCLUSION

Compared to ASF or PSF, VATS procedures showed an initial decline in pulmonary function, which resolved fully by 6- to 12-months follow-up. Modest declines in maximal pulmonary function with VATS-I were seen when comparing all curve types together but not when comparing Lenke 1 curves alone. VATS procedures for thoracic scoliosis and open approaches for thoracolumbar curve types were associated with minimal to no permanent deficits.

Anterior spinal fusion for thoracolumbar scoliosis: comprehensive assessment of radiographic, clinical, and pulmonary outcomes on 2-years follow-up

BACKGROUND

There is a continued role for anterior spinal fusion (ASF) in the treatment of thoracolumbar scoliosis. Despite numerous previous reports of ASF in the treatment of thoracolumbar scoliosis, no single study has simultaneously evaluated clinical, radiographic, and pulmonary function outcomes.

METHODS

Retrospective review of 31 consecutive thoracolumbar adolescent idiopathic scoliosis patients (Lenke type 5) who underwent ASF by a single surgeon. Patient records were comprehensively assessed for Scoliosis Research Society (SRS)-22 score, apical trunk rotation, radiographic changes, and pulmonary function before surgery and at 2-years follow-up.

RESULTS

Thoracolumbar/lumbar curve correction averaged from 45 to 11 degrees (74%) and spontaneous correction of thoracic curves averaged from 26 to 15 degrees (42%). Instrumented segment lordosis increased by 11 degrees, whereas proximal junction kyphosis increased by 3 degrees. No significant changes were noted in T2-T12 kyphosis, distal junctional kyphosis, T12-S1 lumbar lordosis, or coronal balance. Thoracolumbar apical trunk rotation improved from 12 to 3 degrees. Average SRS scores significantly improved from 3.9 to 4.4. SRS assessments of self-image and pain also improved significantly from 3.6 to 4.5 and from 4.1 to 4.6, respectively. Absolute and percent predicted forced vital capacity and forced expiratory volume in 1 second were unchanged. Two patients suffered mild intercostal neuralgia postthoracotomy. There were no other complications.

CONCLUSIONS

The thoracoabdominal anterior approach for thoracolumbar scoliosis facilitates excellent clinical and radiographic outcomes, minimal blood loss, powerful apical trunk rotation correction, relative maintenance of lordosis, relatively short fusion constructs, and improved SRS-22 performance, without significant pulmonary function impairment at 2 years. It continues to be an efficacious treatment for thoracolumbar scoliosis.

LEVEL OF EVIDENCE

Level IV.

Video-assisted thoracoscopic surgery plus lumbar mini-open surgery for adolescent idiopathic scoliosis

PURPOSE

The objectives of this study are to describe the outcome of adolescent idiopathic scoliosis (AIS) patients treated with Video Assisted Thoracoscopic Surgery (VATS) plus supplementary minimal incision in the lumbar region for thoracic and lumbar deformity correction and fusion.

MATERIALS AND METHODS

This is a case series of 13 patients treated with VATS plus lumbar mini-open surgery for AIS. A total of 13 patients requiring fusions of both the thoracic and lumbar regions were included in this study: 5 of these patients were classified as Lenke type 1A and 8 as Lenke type 5C. Fusion was performed using VATS up to T12 or L1 vertebral level. Lower levels were accessed via a small mini-incision in the lumbar area to gain access to the lumbar spine via the retroperitoneal space. All patients had a minimum follow-up of 1 year.

RESULTS

The average number of fused vertebrae was 7.1 levels. A significant correction in the Cobb angle was obtained at the final follow-up (p = 0.001). The instrumented segmental angle in the sagittal plane was relatively well-maintained following surgery, albeit with a slight increase. Scoliosis Research Society-22 (SRS-22) scores were noted have significantly improved at the final follow-up (p < 0.05).

CONCLUSION

Indications for the use of VATS may be extended from patients with localized thoracic scoliosis to those with thoracolumbar scoliosis. By utilizing a supplementary minimal incision in the lumbar region, a satisfactory deformity correction may be accomplished with minimal post-operative scarring.

Male-female differences in Scoliosis Research Society-30 scores in adolescent idiopathic scoliosis

STUDY DESIGN

Longitudinal cohort study.

OBJECTIVE

To compare functional outcomes between male and female patients before and after surgery for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

There is no clear consensus in the existing literature with respect to sex differences in functional outcomes in the surgical treatment of AIS.

METHODS

A prospective, consecutive, multicenter database of patients who underwent surgical correction for adolescent idiopathic scoliosis was analyzed retrospectively. All patients completed Scoliosis Research Society-30 (SRS-30) questionnaires before and 2 years after surgery. Patients with previous spine surgery were excluded. Data were collected for sex, age, Risser grade, previous bracing history, maximum preoperative Cobb angle, curve correction at 2 years, and SRS-30 domain scores. Paired sample t tests were used to compare preoperative and postoperative scores within each sex. Independent sample t tests were used to compare scores between sexes. A P value of <0.05 was considered statistically significant.

RESULTS

Seven hundred forty-four patients (621 females and 123 males) were included. On average, males were 1 year older than females. There were no differences between sexes in Risser grade, bracing history, maximum curve magnitude, or correction after surgery. Both males and females had similar improvement in all SRS-30 domains after surgery. Self-image/appearance had the greatest relative improvement. Males had better self-image/appearance scores preoperatively, better pain scores at 2 years, and better mental health and total scores both preoperatively and at 2 years. Both males and females were similarly satisfied with surgery.

CONCLUSIONS

Males treated with surgery for AIS report better preoperative self-image, less postoperative pain, and better mental health than females. These differences may be clinically significant. For both males and females, the most beneficial effect of surgery is improved self-image/appearance. Overall, the benefits of surgery for AIS are similar for both sexes.

The relationship between deformity correction and clinical outcomes after thoracoscopic scoliosis surgery: a prospective series of one hundred patients

STUDY DESIGN

Prospective clinical case series of 100 patients receiving thoracoscopic anterior scoliosis correction.

OBJECTIVE

To evaluate the relationship between clinical outcomes of thoracoscopic anterior scoliosis surgery and deformity correction, using the Scoliosis Research Society (SRS) outcomes instrument.

SUMMARY OF BACKGROUND DATA

Surgical treatment of scoliosis is quantitatively assessed in the clinic, using radiographic measures of deformity correction and the rib hump, but it is important to understand the extent to which these quantitative measures correlate with self-reported improvements in patients' quality of life after surgery.

METHODS

A series of 100 consecutive adolescent idiopathic scoliosis patients received a single anterior rod via a thoracoscopic approach at the Mater Children's Hospital, Brisbane, Australia. Patients completed SRS outcomes questionnaires before surgery and at 24 months after surgery. Multiple regression and t tests were used to investigate the relationship between SRS scores and deformity correction achieved (radiographic measurements and rib hump) after surgery.

RESULTS

There were 94 females and 6 males with a mean age of 16.1 years. The mean Cobb angle improved from 52° before surgery to 25° after surgery (52%) and the mean rib hump improved from 16° to 8° (51%). The mean total SRS score for the cohort was 99.4/120. None of the deformity-related parameters in the multiple-regression were significant. However, patients with the lowest postoperative major Cobb angles reported significantly higher SRS scores than those with the highest postoperative Cobb angles, but there was no difference on the basis of rib hump correction. There were no significant differences between patients with either rod fractures or screw-related complications compared to those without complications.

CONCLUSION

Patients undergoing thoracoscopic anterior scoliosis correction reported good SRS scores which are comparable with those in previous studies. Postoperative major Cobb angle is a significant predictor of patient satisfaction when comparing subgroups of patients with the highest and lowest postoperative Cobb angles.

The minimum clinically important difference in Scoliosis Research Society-22 Appearance, Activity, And Pain domains after surgical correction of adolescent idiopathic scoliosis

STUDY DESIGN

Longitudinal cohort.

OBJECTIVE

To determine the minimum clinically important difference (MCID) of the Scoliosis Research Society (SRS)-22 Appearance, Activity, and Pain domains in patients with adolescent idiopathic scoliosis undergoing surgical correction of their spinal deformity.

SUMMARY OF BACKGROUND DATA

The MCID, a threshold of improvement that is clinically relevant to the individual patient, is increasingly used to evaluate treatment effectiveness. MCID values for the SRS-22 domains have not been determined.

METHODS

Patients with adolescent idiopathic scoliosis who underwent surgical correction and had completed SRS-22 before operation and the SRS-30 and Scoliosis Appearance Questionnaire (SAQ) at 1 year after operation from a multicenter database for pediatric scoliosis were identified. The SAQ is a modification of the Walter Reed Visual Assessment Scale and is used to assess the patient's perception of their spinal deformity. Paired sample t tests were used to compare preoperative and 1-year postoperative scores. Spearman correlations were used to evaluate associations between domain scores and summed responses to anchors for Appearance, Activity, and Pain. MCID values for the SRS-22 domains were determined using receiver operating characteristic curve analysis, with summed responses to anchor questions 23 to 30 of the SRS-30 and items 26 and 32 of the SAQ.

RESULTS

There were 735 women and 152 men with a mean age of 14.3 years and a mean Cobb angle of 53°. There was a statistically significant difference between paired preoperative and 1-year SRS domain scores. Analysis of variance showed a statistically significant difference between the summed responses to the anchors. The MCID was 0.20 for the Pain domain (area under the curve [AUC] = 0.723), 0.08 for Activity (AUC = 0.648), and 0.98 for Appearance (AUC = 0.629). The MCID for activity was less than the standard error of measurement.

CONCLUSION

The MCID for the Pain domain was 0.20 and 0.98 for Appearance. Because these patients were generally in good health, a minimal though significant change in activity was observed, such that the calculated MCID was within the measurement error. As expected, the largest and most important change was in the Appearance domain. Future studies are needed to determine the MCID for the mental domain and the total SRS score and to further validate the MCID values in this study.

Thoracoscopic anterior instrumentation for idiopathic scoliosis

Lonner BS, Auerbach JD, Levin R, et al. Thoracoscopic anterior instrumented fusion for adolescent idiopathic scoliosis with emphasis on the sagittal plane. Spine J 2009;9:523-9 (this issue).