The treatment of large (>70 degrees) thoracic idiopathic scoliosis curves with posterior instrumentation and arthrodesis: when is anterior release indicated?

Analysis of duration of different stages of surgery in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) patients: comparison between severe versus non-severe AIS

PURPOSE

Prolonged surgical duration in severe adolescent idiopathic scoliosis (AIS) patients is associated with increased blood loss and perioperative complications. The aim of this study was to compare the duration of each stage of posterior spinal fusion (PSF) in severe AIS (Cobb angle ≥ 90°) with non-severe AIS patients. This analysis will identify the most time-consuming stage of PSF and help surgeons formulate strategies to shorten operative time.

METHODS

Retrospective study whereby 90 AIS patients (Lenke type 2, 3, 4, and 6) who underwent PSF from 2019 to 2023 were recruited. Twenty-five severe AIS patients were categorized in Gp1 and 65 non-severe AIS patients in Gp2. Propensity score matching (PSM) with one-to-one with nearest neighbor matching (match tolerance 0.05) was performed. Outcomes measured via operation duration of each stage of surgery, blood loss, number of screws, fusion levels and screw density.

RESULTS

Twenty-five patients from each group were matched. Total operative time was significantly higher in Gp1 (168.2 ± 30.8 vs. 133.3 ± 24.0 min, p < 0.001). The lengthiest stage was screw insertion which took 58.5 ± 13.4 min in Gp1 and 44.7 ± 13.7 min in Gp2 (p = 0.001). Screw insertion contributed 39.5% of the overall increased surgical duration in Gp1. Intraoperative blood loss (1022.2 ± 412.5 vs. 714.2 ± 206.7 mL, p = 0.002), number of screws (17.1 ± 1.5 vs. 15.5 ± 1.1, p < 0.001) and fusion level (13.1 ± 0.9 vs. 12.5 ± 1.0, p = 0.026) were significantly higher in Gp1.

CONCLUSION

Screw insertion was the most time-consuming stage of PSF and was significantly longer in severe AIS. Adjunct technologies such as CT-guided navigation and robotic-assisted navigation should be considered to reduce screw insertion time in severe AIS.

Can anterior vertebral body tethering provide superior range of motion outcomes compared to posterior spinal fusion in adolescent idiopathic scoliosis? A systematic review

PURPOSE

Anterior vertebral body tethering (AVBT) was introduced as a fusionless alternative to treating adolescent idiopathic scoliosis (AIS) while preserving range of motion (ROM). This is the first systematic review to compare the ROM outcomes between AVBT and PSF in treating AIS.

METHODS

We conducted a comprehensive search on PubMed, EMBASE, MEDLINE, and Cochrane Library. Inclusion criteria were patients with AIS treated with AVBT or PSF or both, and clearly defined ROM outcomes; exclusion criteria were scoliosis other than AIS, biomechanical or cadaveric studies, non-English publications, case reports, conference summaries, unpublished literature, commentaries, and reviews. Primary outcome was ROM. Secondary outcomes included Cobb angle correction, quality of life (QOL), complications, and muscle strength and endurance.

RESULTS

Twelve studies were included in this review. We found moderate evidence to support that AVBT results in superior ROM outcomes than PSF while achieving comparable Cobb angle correction with low evidence. The comparison of QOL outcomes between AVBT and PSF remained inconclusive. In addition to the complications noted conventionally in PSF, AVBT could result in over-correction and distal adding-on. We also found very low evidence to support that AIS patients treated with AVBT have superior muscle strength and endurance when compared to those treated with PSF.

CONCLUSIONS

AVBT provides better preservation of ROM and muscle strength postoperatively when compared with PSF, while achieving comparable curve correction. Future studies should explore the spinal growth trajectory to determine the window of opportunity for AVBT in AIS.

Preoperative MRI and Intraoperative Monitoring Differentially Prevent Neurological Sequelae in Idiopathic Scoliosis Surgical Correction, While Curves >70 Degrees Increase the Risk of Neurophysiological Incidences

The aim was to investigate the role of preoperative magnetic resonance imaging (MRI) and intraoperative monitoring (IOM) in the prevention of correction-related complications in idiopathic scoliosis (IS). We conducted a retrospective case study of 129 patients with juvenile and adolescent IS. The operations took place between 2005 and 2018 in Uppsala University Hospital. Data from MRI scans and IOM were collected. The patients were divided into groups depending on Lenke’s classification, sex, major curve (MC) size, and onset age. Neurophysiological incidences were reported in ten patients (7.8%), while nine of them had no signs of intraspinal pathology. Six patients (4.7%) had transient incidences; however, in four patients (3.1%), an intervention was required for the normalization of action potentials. Three of them had an MC >70 degrees, which was significantly higher than the expected value. Eight patients (6.1%) had intraspinal pathologies, and two of them (1.5%) underwent decompression. We suggest the continuation of MRI screening preoperatively and, most importantly, the use of IOM. In three cases with no signs of pathology in the MRI, IOM prevented possible neurological injuries. MCs >70 degrees should be considered a risk factor for the occurrence of neurophysiological deficiencies that require action to be normalized.

Surgical outcomes of severe spinal deformities exceeding 100° or treated by vertebral column resection (VCR). Does implant density matter?: an observational study of deformity groupings

STUDY DESIGN

Prospective multicenter international observational study.

OBJECTIVE

To investigate the effect of implant density on clinical outcomes in complex pediatric spine reconstruction. Implant density in spine deformity surgery has been a subject of much debate with some authors advocating higher density for better correction. Few studies have looked at the effect of implant density on severe curves > 100 deg or treated with vertebral column resection (VCR).

METHODS

250/311 pts with 2-year f/u enrolled in the FOX pediatric database from 17 international sites were queried for the impact of implant density and surgical outcomes. Patients were grouped into three implant density categories for comparative analysis Group 1 (density ≤ 1), Group 2 (1 < density < 1.5) and Group 3 (density; 1.5-2).

RESULTS

250 pts: 47 (Grp1)/99 (Grp2) /104 (Grp3); Pre-op age and etiology and curve types were similar in all groups, but body mass index (BMI) was higher in Grp3. Grps 1 and 2 had significantly higher sagittal deformity angular ratio (S-DAR) compared to Grp 3 (p < 0.001). Pre-op Halo Gravity Traction (HGT) was used in 55.3%/44.4%/31.7%, p = 0.017; Grp1/Grp2/Grp3, respectively. Average duration of surgery (min) was higher in Grp3 relative to Grp1 only: 352.5/456.5/515.0, p = 0.0029. Blood loss was similar in all Grps. Rate of VCR, PSO and SPO was similar in all Grps. Pre-op Coronal Cobb avg 96.1/83.6/88.6, p = 0.2342, attained similar correction after HGT (24.6%/27.2%/23.2%, p = 0.4864. Coronal Cobb corrections at 2-year follow-up (FU) were (37.1%/40.3%/53.5%, p = 0.0004). Pre-op sagittal Cobb was (105.4/101.9/75.9, p < 0.01.), achieved similar %correction in HGT (19.1%/22.3%/22.5%, p = 0.6851) and at 2-year FU (39.6%/41.4%/29.8%, p = 0.1916). After adjusting for C-DAR, S-DAR, pre-op coronal and sagittal Cobb, etiology, curve types, age, BMI and number of rods in multivariate analysis, the odds of developing post-operative implant complication was 11 times greater in group 1 compared to group 3 (OR = 11.17,95% CI 2.34-53.32). There was significant improvement in SRS scores in all Grps at 2-year FU.

CONCLUSION

Although higher implant density was observed to be associated with greater curve correction and lower rates of post-operative implant-related complication and revision in heterogeneous case groups, the results may not imply causality of implant density on the outcomes in severe pediatric spine reconstruction.

Learning Curve for a Dual Attending Surgeon Strategy in Posterior Spinal Fusion (PSF): An Analysis of 105 Severe Adolescent Idiopathic Scoliosis Patients (Cobb Angle ≥90°)

STUDY DESIGN

Retrospective study.

OBJECTIVE

To assess the learning curve of a dual attending surgeon strategy in severe adolescent idiopathic scoliosis patients.

SUMMARY OF BACKGROUND DATA

The advantages of a dual attending surgeon strategy in improving the perioperative outcome in scoliosis surgery had been reported. However, the learning curve of this strategy in severe scoliosis had not been widely studied.

METHODS

A total of 105 patients with adolescent idiopathic scoliosis with Cobb angle of 90° or greater, who underwent posterior spinal fusion using a dual attending surgeon strategy were recruited. Primary outcomes were operative time, total blood loss, allogeneic blood transfusion requirement, length of hospital stay from time of operation and perioperative complications. Cases were sorted chronologically into group 1: cases 1 to 35, group 2: cases 36 to 70, and group 3: case 71 to 105. Mean operative time (≤193.3 min), total blood loss (≤1612.2 mL), combination of both and allogeneic blood transfusion were the selected criteria for receiver operating characteristic analysis of the learning curve.

RESULTS

The mean Cobb angle was 104.5° ± 12.3°. The operative time, total blood loss, and allogeneic blood transfusion requirement reduced significantly for group 1 (220.6 ± 54.8 min; 2011.3 ± 881.8 mL; 12 cases) versus group 2 (183.6 ± 36.7 min; 1481.6 ± 1035.5 mL; 3 cases) and group 1 versus group 3 (175.6 ± 38.4 min; 1343.7 ± 477.8 mL; 3 cases) (P < 0.05). There were six perioperative complications. Fifty-seven cases were required to achieve the preset criteria (mean operative time and mean total blood loss) (area under the curve 0.740; P < 0.001; sensitivity 0.675; specificity 0.662).

CONCLUSION

There was significant improvement in operative time and total blood loss when comparing group 1 versus group 2 and group 1 versus group 3. The cut-off point for the learning curve was 57 cases when the preset criteria were fulfilled (≤193.3 min operative time and ≤1612.2 mL of total blood loss).Level of Evidence: 4.

Operative time in adolescent idiopathic scoliosis surgery: a need for a standard definition

Our objective is to report and define 'operative time' in adolescent idiopathic scoliosis (AIS) posterior spinal fusion surgeries. Documenting key times during surgery are important to compare operative risks, assess learning curves, and evaluate team efficiency in AIS surgery. 'Operative time' in literature has not been standardized. Systematic review was performed by two reviewers. Keywords included operative time, duration of surgery, and scoliosis. One thousand nine hundred six studies were identified, 1092 duplicates were removed and 670 abstracts were excluded. Of the 144 articles, 67 met inclusion and exclusion criteria. Studies were evaluated for number of patients, operative time, and definition of operative time. Meta-analysis was not performed due to confounders. Of the 67 studies (6678 patients), only 14 (1565 patients) defined operative time, and all specified as incision to closure. From these 14 studies, the median operative time was 248 minutes (range 174-448 minutes). In the 53 studies (5113 patients) without a definition, one study reported time in a non-comparable format, therefore, data were analyzed for 52 studies (5078 patients) with a median operative time of 252 minutes (wider range 139-523 minutes). A clear standardized definition of operative or surgical time in spine surgery does not exist. We believe that operative time should be clearly described for each published study for accurate documentation and be defined from incision time to spine dressing completion time in order to standardize study results. Level of evidence: IV.

Predictive factors for correction rate in severe idiopathic scoliosis (Cobb angle ≥ 90°): an analysis of 128 patients

PURPOSE

Knowledge on the factors affecting the correction rate (CR) aids in the surgical planning among severe idiopathic scoliosis (IS) patients. This study aimed to investigate the independent factors affecting CR among patients with severe IS (Cobb angle ≥ 90°) who underwent single-staged posterior spinal fusion (PSF).

METHODS

We retrospectively reviewed 128 severe IS patients who underwent single-staged PSF. Factors including age, height, weight, body mass index, Risser sign, Lenke subtypes, preoperative major Cobb angle, side bending major Cobb angle, side bending flexibility (SBF), motion segments of the major curve, AR curve, number of levels fused, screw density, operative time and postoperative major Cobb angle were analysed using linear regression analysis.

RESULTS

The mean age was 15.5 ± 4.5 years with mean Risser sign of 3.1 ± 1.6. The mean preoperative Cobb, SBF, postoperative Cobb and CR were 102.8 ± 12.3°, 37.5 ± 13.7%, 44.4 ± 13.5° and 57.2 ± 10.8%, respectively. From stepwise multiple linear regression analysis, SBF, Risser sign and AR curve were the independent predictive factors for CR, with R² value of 0.345 (p < 0.001). CR can be predicted using the formula: 47.21 + (0.34 × SBF)-(1.47 × Risser sign) + (3.69 × AR), where AR = 1 and non-AR = 0.

CONCLUSION

The flexibility of the major curve, Risser sign and AR curve were the most important predictors for CR in a single-staged PSF among patients with severe IS.

Long-term experience with simultaneous prone video-assisted thoracoscopic anterior spinal release and posterior spinal fusion in severe rigid pediatric spinal deformities

PURPOSE

While posterior-alone techniques have been successful for most pediatric spinal deformities, anterior spinal release may be useful for severe rigid deformities. Traditional lateral-positioned video-assisted thoracoscopic surgical release (VATSR) followed by prone posterior spinal fusion (PSF) has been criticized for adding extensive operative morbidity. We aimed to reduce its disadvantages by performing prone VATSR and PSF simultaneously and evaluate its long-term outcomes.

METHODS

All consecutive patients from 1991 to 2012 undergoing VATSR and PSF at one institution were retrospectively reviewed. The inclusion criteria comprised severe rigid thoracic scoliosis (> 70°, bending correction > 45°) or kyphosis (> 75°, bolster correction > 45°), and a minimum 2 year follow-up. Demographics, operative data, hospital stay, and radiographic correction data were compared between patients who had undergone sequential VATSR followed by PSF and those who had undergone these procedures simultaneously.

RESULTS

Of 153 patients who had undergone VATSR and PSF, 53 met the inclusion criteria (31 sequential, 22 simultaneous; average follow-up, 50 [range, 24-86] months). Age, preoperative measurements and flexibility, and perioperative complications did not differ significantly. The simultaneous group showed significantly lower operative time (449 vs. 618 min), blood loss (1039 vs. 1906 cc), and hospital stay (6.3 vs. 8.5 days) (all, p < 0.05). Postoperative radiographic correction and maintenance at the final follow-up showed a non-significant trend favoring the simultaneous group.

CONCLUSION

Our simultaneous prone VATSR and PSF technique showed significantly lower operative time, blood loss, and hospital stay compared with the traditional sequential VATSR and PSF method, suggesting its value in treating rigid deformities.

Cost-effectiveness of surgical treatment of adult spinal deformity: comparison of posterior-only versus anteroposterior approach

BACKGROUND CONTEXT

Considerable debate exists regarding the optimal surgical approach for adult spinal deformity (ASD). It remains unclear which approach, posterior-only or combined anterior-posterior (AP), is more cost-effective. Our goal is to determine the 2-year cost per quality-adjusted life year (QALY) for each approach.

PURPOSE

To compare the 2-year cost-effectiveness of surgical treatment for ASD between the posterior-only approach and combined AP approach.

STUDY DESIGN

Retrospective economic analysis of a prospective, multicenter database PATIENT SAMPLE: From a prospective, multicenter surgical database of ASD, patients undergoing five or more level fusions through a posterior-only or AP approach were identified and compared.

METHODS

QALYs gained were determined using baseline, 1-year, and 2-year postoperative Short Form 6D. Cost was calculated from actual, direct hospital costs including any subsequent readmission or revision. Cost-effectiveness was determined using cost/QALY gained.

RESULTS

The AP approach showed significantly higher index cost than the posterior-only approach ($84,329 vs. $64,281). This margin decreased at 2-year follow-up with total costs of $89,824 and $73,904, respectively. QALYs gained at 2 years were similar with 0.21 and 0.17 in the posterior-only and the AP approaches, respectively. The cost/QALY at 2 years after surgery was significantly higher in the AP approach ($525,080) than in the posterior-only approach ($351,086).

CONCLUSIONS

We assessed 2-year cost-effectiveness for the surgical treatment through posterior-only and AP approaches. The posterior-only approach is less expensive both for the index surgery and at 2-year follow-up. The QALY gained at 2-years was similar between the two approaches. Thus, posterior-only approach was more cost-effective than the AP approach under our study parameters. However, both approaches were not cost-effective at 2-year follow-up.

Extreme long-term outcome of operatively versus conservatively treated patients with adolescent idiopathic scoliosis

PURPOSE

We report on outcomes of surgically versus (vs) non-surgically treated patients with moderate adolescent idiopathic scoliosis (AIS) after minimum of 29 years.

METHODS

AIS patients with a follow-up of  ≥ 41 years in the surgical group and  ≥ 29 years in the non-surgical group were included. Patients were treated surgically for primary curves  ≥ 45° vs non-surgically for curves  < 45° or refusal of surgery. Groups were matched for age, gender, comorbidities and primary curve severity. Oswestry Disability Index (ODI) was used to measure clinical outcomes and standard radiography to quantify curve severity at final follow-up.

RESULTS

In total, 16 patients (8 within each group, 75% females) with a median age of 14 (interquartile range (IQR) 2) years could be included and were followed up after 46 (IQR 12) years. All matched variables were similar for both groups, including the primary curve Cobb angles of 48° (IQR 17°) (surgical) vs 40° (IQR 19°) (non-surgical); p = 0.17). At final follow-up after a median of 47 (IQR 5) years for the surgical and 39 (IQR 19) years for the non-surgical group (p = 0.43), the ODI was similar for both groups (15 (IQR 13) points (surgical) vs 7 (IQR 15) points (non-surgical); p = 0.17) with, however, a primary curve magnitude lower in the surgical compared to the non-surgical group (38° (IQR 3°) vs 61° (IQR 33°); p = 0.01), respectively.

CONCLUSION

After around 47 and 39 years, respectively, surgical and non-surgical treatment of moderate AIS showed similar subjective outcomes, but with a relevant smaller curve magnitude with surgical treatment.

LEVEL OF EVIDENCE

III.

Perioperative Outcome of Severe Idiopathic Scoliosis (Cobb Angle ≥ 90°): Is There Any Difference Between "Daytime" Versus "After-hours" Surgeries?

STUDY DESIGN

Retrospective study from a prospectively collected database.

OBJECTIVE

To compare the perioperative outcome between after-hours and daytime surgery carried out by a dedicated spinal deformity team for severe Idiopathic Scoliosis (IS) patients with Cobb angle ≥ 90°.

SUMMARY OF BACKGROUND DATA

There were concerns that after-hours corrective surgeries in severe IS have higher morbidity compared to daytime surgeries.

METHODS

Seventy-one severe IS patients who underwent single-staged Posterior Spinal Fusion (PSF) were included. Surgeries performed between 08:00H and 16:59H were classified as "daytime" group and surgeries performed between 17:00H and 06:00H were classified as "after-hours" group. Perioperative outcome parameters were average operation start time and end time, operation duration, intraoperative blood loss, intraoperative hemodynamic parameters, preoperative and postoperative hemoglobin, blood transfusion rate, total patient-controlled anesthesia (PCA) morphine usage, length of postoperative hospitalization, and complications. Radiological variables assessed were preoperative and postoperative Cobb angle, side bending flexibility, number of fusion levels, number of screws used, Correction Rate, and Side Bending Correction Index.

RESULTS

Thirty patients were operated during daytime and 41 patients were operated after-hours. The mean age was 16.1 ± 5.8 years old. The mean operation start time for daytime group was 11:31 ± 2:45H versus 19:10 ± 1:24H for after-hours group. There were no significant differences between both groups in the operation duration, intraoperative blood loss, intraoperative hemodynamic parameters, postoperative hemoglobin, hemoglobin drift, transfusion rate, length of postoperative hospitalization, postoperative Cobb angle, Correction Rate, and Side Bending Correction Index. There were four complications (1 SSEP loss, 1 massive blood loss, and 2 superficial wound infections) with no difference between daytime and after-hours group.

CONCLUSION

After-hours elective spine deformity corrective surgeries in healthy ambulatory patients with severe IS performed by a dedicated spinal deformity team using dual attending surgeon strategy were as safe as those performed during daytime.

LEVEL OF EVIDENCE

4.

Patient-Reported SRS-24 Outcomes Scores After Surgery for Adolescent Idiopathic Scoliosis Have Improved Since the New Millennium

STUDY DESIGN

Observational.

OBJECTIVE

To examine changes in patient-reported two-year postoperative outcomes via the Scoliosis Research Society (SRS)-24 Outcomes Instrument from 2001 through 2015.

SUMMARY OF BACKGROUND DATA

Techniques for correction of adolescent idiopathic scoliosis (AIS) have evolved over the years, but it is unclear how these changes have impacted patient-reported outcomes.

METHODS

AIS patients with two-year postoperative follow-up from a prospective multicenter registry were divided into three-year groups based on trends in surgical approach and construct type (2010-2014: 52% anterior, 43% posterior hybrids; 2005-2011: 3% anterior, 5% posterior hybrids; 2012-2015: 0% anterior, 0.2% posterior hybrids). Because of the ordinal scale (1-5) and bipolar nature of the response sets for the SRS-24, domain/total scores were categorized as ≤3 (predominantly negative) or 4-5 (predominantly positive). Variables were compared across the three groups.

RESULTS

A total of 1,695 patients were analyzed; 172 (2010-2014), 926 (2005-2011), and 597 (2012-2015). Average age was 14.7 ± 2 years, the average primary curve was 55° ± 13°, and the group was primarily female (82%). There was a decline in the rate of positive scores for preoperative pain and self-image across the three groups (p < .05). There was an increase in the rate of positive scores for two-year postoperative self-image after surgery, function after surgery, and satisfaction (p < .05). Decreases in length of hospital stay, blood loss, surgical time, preoperative kyphosis, and postoperative trunk shift were observed (p < .05). Increases were observed in levels fused, preoperative major coronal curve, preoperative rib prominence, preoperative trunk shift, percentage correction of major curve, kyphosis restoration, and the rate of double/triple curves (p < .05).

CONCLUSION

The percentage of patients with positive postoperative SRS scores has increased in the modern era, providing evidence that newer surgical techniques are resulting in improved outcomes based on the patients' perspectives. Interestingly, recent patients were more afflicted with negative pain and self-image before surgery.

Anterior and Posterior Fusion for Large, Rigid Idiopathic Scoliosis: Does Implant Density Matter?

BACKGROUND

Despite advancements in surgical techniques, controversy remains regarding the optimal implant density for the correction of idiopathic scoliosis. Recent evidence has suggested that equivalent radiographic and clinical outcomes can be achieved with lower implant densities for those with moderate curves and good flexibility. Among the experts, the consensus has continued that higher implant densities should be used for larger, stiffer curves. The purpose of the present study was to compare the radiographic results between high-implant density (HID) and low-implant density (LID) constructs in patients with large (>65°), rigid (<50% flexibility) curves who had undergone anterior release and posterior spinal fusion.

METHODS

We reviewed the idiopathic scoliosis cases performed at a single institution from 2006 to 2014. Only those meeting the inclusion criteria were selected. The patients were divided into HID and LID groups. The postoperative radiographs were compared for coronal correction, thoracic kyphosis, pelvic tilt, lumbar lordosis, and sagittal vertical axis.

RESULTS

A statistically significant improvement in coronal correction was detected in the HID group at all follow-up points (final follow-up: HID, 81.1% vs. LID, 70.4%; P = 0.01). When preoperative thoracic kyphosis was considered, no differences were found between the 2 groups. No differences were found in the other sagittal parameters.

CONCLUSION

In patients with large, rigid idiopathic scoliosis undergoing anterior release and posterior spinal fusion, a small, but statistically, significant improvement in the coronal Cobb angle was seen. It remains to be determined whether this small difference in radiographic correction will have any influence on the clinical outcome.

Perioperative Outcome of Single Stage Posterior Spinal Fusion for Severe Adolescent Idiopathic Scoliosis (AIS) (Cobb Angle ≥90°): The Role of a Dual Attending Surgeon Strategy

STUDY DESIGN

Retrospective study.

OBJECTIVE

To evaluate the perioperative outcome of dual attending surgeon strategy for severe adolescent idiopathic scoliosis (AIS) patients with Cobb angle more than or equal to 90°.

SUMMARY OF BACKGROUND DATA

The overall complication rate for AIS remains significant and is higher in severe scoliosis. Various operative strategies had been reported for severe scoliosis. However the role of dual attending surgeon strategy in improving the perioperative outcome in severe scoliosis has not been investigated.

METHODS

The patients were stratified into two groups, Cobb angles 90° to 100° (Group 1) and more than 100° (Group 2). Demographic, intraoperative, preoperative, and postoperative day 2 data were collected. The main outcome measures were intraoperative blood loss, use of allogeneic blood transfusion, operative time, duration of hospital stay postsurgery, and documentation of any perioperative complications.

RESULTS

Eighty-five patients were recruited. The mean age for the whole cohort was 16.2 ± 5.2 years old. The mean age of Group 1 was 16.7 ± 5.7 and Group 2 was 15.6 ± 4.8 years old. The majority of the patients in both groups were Lenke 2 curves with the average Cobb angle of 93.9 ± 3.0° in Group 1 and 114.2 ± 10.2° in Group 2. The average operative time was 198.5 ± 47.5 minutes with an average blood loss of 1699.5 ± 939.3 mL. The allogeneic blood transfusion rate was 17.6%. The average length of stay postoperation was 71.6 ± 22.5 hours. When comparing the patients between Group 1 and Group 2, the operating time, total blood loss, allogeneic transfusion rate showed significant intergroup differences. Five complications were documented (one intraoperative seizure, one massive blood loss, one intraoperative loss of somatosensory evoked potential (SSEP) signal, and two superficial wound breakdown).

CONCLUSION

Dual attending surgeon strategy in severe AIS more than or equal to 90° demonstrated an average operative time of 199 minutes, intraoperative blood loss of 1.7 L, postoperative hospital stay of 71.6 hours, and a complication rate of 5.9% (5/85 patients). Curves with Cobb angle more than 100° lead to longer operating time, greater blood loss, and allogeneic transfusion rate.

LEVEL OF EVIDENCE

4.

Over 70° thoracic idiopathic scoliosis: Results with screws or hybrid constructs

Background:

Adolescent idiopathic scoliosis is the most common type of scoliosis. High degrees curve can be treated with the anterior, posterior, or combined anterior–posterior approach. Contrarily to the anterior approach, the posterior one is widely used nowadays for its good correction outcomes and relatively low-complication rate.

Materials and Methods:

We evaluated retrospectively 27 patients, treated with posterior approach. Patients were divided into two groups, namely pedicle screws group (PSG) and hybrid group (pedicle screws + sublaminar bands). Radiographic measurements, including thoracic and lumbar Cobb° measurements of primary and secondary curves, coronal balance and sagittal balance, kyphosis and lordosis, curve flexibility, first and last vertebra included in the arthrodesis, and implant density were evaluated. Clinical patients' satisfaction was also evaluated with Scoliosis Research Society (SRS) 24 questionnaire.

Results:

Considering both groups, on preoperative X-rays, the average primary scoliotic curve angle was 83.56° ± 10.96° (range 70°–112°), whereas the global flexibility was 64° ± 7.63 (range 46°–72°). The curves were classified following the Lenke classification: 17 Type 1, 2 Type 2, and 8 Type 3. The primary curve resulted to be well corrected in both groups. In T0, the groups were homogeneous, but in T1 and follow-up, PSG stated a better mean value. No other significative differences can be found between groups for all other items (P > 0.05). Clinical results of SRS 24 were excellent in both groups.

Conclusions:

The posterior approach proved to be an excellent technique for obtaining good clinical and radiographic results if the surgeon adopts the third-generation high-density implants.

Level of Evidence:

III.

Intraoperative Halo-Femoral Traction in Surgical Treatment of Adolescent Idiopathic Scoliosis Curves between 70° and 90°: Is It Effective?

Study Design

A retrospective clinical study.

Purpose

To analyze the surgical outcomes of intraoperative halo-femoral traction (HFT) in patients with adolescent idiopathic scoliosis (AIS) with Cobb angles between 70° and 90° and flexibility <35%.

Overview of Literature

Numerous methods have been described to achieve adequate correction and successful results in the surgical treatment of AIS patients with a Cobb angle >70°. However, few studies have evaluated the results of HFT in AIS patients with Cobb angles between 70° and 90° and flexibility <35%.

Methods

The study comprised 24 AIS patients (18 females, six males; mean age, 17.4 years; mean preoperative Cobb angle, 80.1°; range, 70°–90°) who underwent surgery using intraoperative HFT. Neurological status was constantly assessed during the surgery using intraoperative neurophysiological monitoring.

Results

The mean follow-up period was 33.5 months. Radiographic outcomes demonstrated 85.7% correction of the major Cobb angle. Coronal and sagittal balance was achieved in all the patients, and shoulder levels were equalized. The traction was discontinued when a decrease in spinal cord potentials was observed during the surgery.

Conclusions

Intraoperative HFT is an effective and reliable method for the management of scoliosis curves between 70° and 90°. The most significant advantages of the method are avoidance of the morbidities related to anterior surgery, osteotomy, or vertebral column resection; its contribution in helping achieve adequate reduction and optimum balance by the gradually increased corrective force, lack of any need for extreme correction force during instrumentation; and the high correction rates achieved.

Surgical correction of severe spinal deformities using a staged protocol of external and internal techniques

INTRODUCTION

There is high risk of neurologic complications in one-stage management of severe rigid spinal deformities in adolescents. Therefore, gradual spine stretching variants are applied. One of them is the use of external transpedicular fixation.

PURPOSE

Our aim was to retrospectively study the outcomes of gradual correction with an apparatus for external transpedicular fixation followed by internal fixation used for high-grade kyphoscoliosis in adolescents.

METHODS

Twenty five patients were reviewed (mean age, 15.1 ± 0.4 years). Correction was performed in two stages: 1) gradual controlled correction with the apparatus for external transpedicular fixation; and 2) internal posterior transpedicular fixation. Rigid deformities in eight patients required discapophysectomy. Clinical and radiographic study of the outcomes was conducted immediately after treatment and at a mean long-term period of 3.8 ± 0.4 years. Pain was evaluated using the visual analogue scale (VAS, 10 points). The Oswestry questionnaire (ODI scale) was used for functional assessment.

RESULTS

Deformity correction with the external apparatus was 64.2 ± 4.6% in the main curve and 60.7 ± 3.7% in the compensatory one. It was 72.8 ± 4.1% and 66.2 ± 5.3% immediately after treatment and 70.8 ± 4.6% and 64.3 ± 4.2% at long term, respectively. Pain relieved by 33.2 ± 4.2% (p < 0.05) immediately after treatment and by 55.6 ± 2.8% (p < 0.05) at long term. ODI reduced by 30.2 ± 1.7% (p < 0.05) immediately after treatment and by 37.2 ± 1.6% (p < 0.05) at long term.

CONCLUSION

The apparatus for external transpedicular fixation provides gradual controlled correction for high-grade kyphoscoliosis in adolescents. Transition to internal fixation preserves the correction achieved, and correction is maintained at long term.

Posterior-only surgery with preoperative skeletal traction for management of severe scoliosis

PURPOSE

The surgical treatment of severe adolescent spinal deformities is challenging and carries substantial risks of mortality and morbidity. To mitigate this risk, surgeons have employed various methods as this study designed to evaluate the safety and effectiveness of preoperative halo-femoral or halo gravity traction (HGT) followed by posterior-only surgery in the management of severe scoliosis.

METHOD

A total number of 23 patients with severe scoliosis treated by preoperative skeletal traction (halo gravity or halo femoral) followed by posterior fusion and instrumentation in one stage. All patients were followed for a minimum of 2 years after surgery.

RESULTS

The average age of the patients was 12.7 years at the time of surgery. Mean of the Cobb angle improved from 99.9° ± 8.2° preoperatively to 75.3° ± 8° post-traction and 49.5° ± 7.7° postoperatively. Kyphosis angle corrected from 56.4° ± 9.5° to 38.6° ± 5.8°. The preop-FVC% was 41 ± 6.1% and after 1 year follow-up FVC% was 45.7 ± 7.7%. No patients required an anterior release due to amount of their deformity.

DISCUSSION

Despite the benefits of modern instrumentation procedures, the treatment of severe scoliosis can be very competing. We think that by applying preoperative halo femoral traction and halo-gravity traction, managing severe scoliosis will be in safe and easy manner and can lead to better deformity correction and less neurological complications and facilitate to avoid anterior operation for severe scoliosis and its related complications.

Thoracoscopic Vertebrectomy for Thoracolumbar Junction Fractures and Tumors: Surgical Technique and Evaluation of the Learning Curve

STUDY DESIGN

Retrospective study.

OBJECTIVE

The authors evaluated the surgical technique and learning curve for video-assisted thoracoscopic surgery (VATS) for treating thoracolumbar junction burst fractures and bony tumors by examining surgical data and outcome for the first 30 VATS procedures performed by a single surgeon at a training institution.

SUMMARY OF BACKGROUND DATA

VATS is commonly used in the treatment of early-stage lung cancer. Widespread use of this technique among neurosurgeons is limited by the lack of cases and the steep learning curve.

METHODS

This study was a retrospective case series of the first 30 T12 and L1 thoracoscopic vertebrectomies from 2003 to 2008. The sample was limited to 1 surgeon and 1 region of the spine to minimize the potential variation so that a learning curve could be assessed. Surgical data and outcomes were analyzed. Estimated blood loss and operation time were analyzed using a linear generalized estimating equation model with a first-order autoregression correlation structure.

RESULTS

The average operative time for thoracoscopic corpectomy was 270±65 minutes (range, 160-416 min). Operating room time decreased significantly after the first 3 operations. The authors observed a stable linear decrease in operating time over the course of the study. The average blood loss during the thoracoscopic procedure was 433±330 mL (range, 100-1500 mL) and did not change as the series progressed. Complications and conversions to open procedures occurred in 2 patients and were evenly distributed throughout the series.

CONCLUSIONS

Thoracoscopic vertebrectomy at the thoracolumbar junction has a relatively long learning curve. In this series, operating room time improved dramatically after the first 3 cases but continued to improve subsequently. The learning curve can be accomplished without an increase in blood loss, complications, rate of conversion to open procedures, or frequency of misplaced instrumentation.

The 15-Year Evolution of the Thoracoscopic Anterior Release: Does It Still Have a Role?

STUDY DESIGN

Retrospective.

PURPOSE

To determine how the indications for anterior thoracoscopic release and fusion have evolved over time.

OVERVIEW OF LITERATURE

Anterior release was commonly performed to correct severe spinal deformities before the advent of pedicle screw fixation. The thoracoscopic approach significantly reduced the morbidity, as compared to open thoracotomy procedures.

METHODS

We reviewed charts and radiographs of pediatric spinal deformity patients who underwent thoracoscopic release/fusion for their deformity from 1994 to 2008. Indications for the thoracoscopic procedure were assigned to one of the following categories: hyperkyphosis, large/stiff scoliosis, crankshaft prevention, and 'other'. We analysed indications grouped in 3-year intervals to determine how the indications for this procedure evolved over the past 15 years.

RESULTS

One hundred and thirty-eight patients (mean age, 15 years; range, 2-28 years) underwent the procedure, with 160 identified indications. The frequency of thoracoscopic anterior release/fusion decreased after peaking in the years 2000-2002. Initially, hyperkyphosis was the most frequent indication (15/33, 45%; 1994-1996), but declined to an intermittent indication since 2006. The use of thoracoscopy to prevent crankshaft has also declined, but remains an indication for the most immature cases (2/17, 12%; 2006-2008). Severe or rigid scoliosis is currently the most common indication for thoracoscopic release/fusion at our center (11/17, 65%; 2006-2008).

CONCLUSIONS

The indications for a thoracoscopic anterior release/fusion has evolved with our increased understanding of this procedure and improved posterior fixation with pedicle screw instrumentation. Thoracoscopy in select spinal deformity patients still has an important role despite its less frequent use, as compared to the past decade.

Biomechanical comparison of ponte osteotomy and discectomy

STUDY DESIGN

Biomechanical cadaver study.

OBJECTIVE

To evaluate the relative effectiveness of Ponte osteotomies for spinal release in deformity correction.

SUMMARY OF BACKGROUND DATA

Controversy exists as to the role of Ponte osteotomy in deformity correction surgery. Very little has been written about the biomechanical effects of Ponte osteotomy. Past biomechanical studies have been limited to application of forces through endplates, single functional units, or lack of comparison with anterior release.

METHODS

Twelve fresh-frozen human full thoracic spinal units were tested for motion in axial rotation, flexion/extension, and lateral bending in a custom-designed robotic environment. Testing was repeated after sequential facetectomy and Ponte osteotomy (6 specimens) and compared with partial and full discectomy (6 specimens).

RESULTS

Motion in axial rotation is increased 21% by Ponte osteotomy compared with 35% for full discectomy. Anterior displacement of the spinal column, creating lordosis, was increased 15% by Ponte osteotomy and 40% by full discectomy. Posterior displacement of the spinal column, creating kyphosis, was increased 23% by Ponte osteotomy and 89% by full discectomy. Finally, in coronal force application the Ponte osteotomy had virtually no effect (2%) compared with 40% increased motion by full discectomy.

CONCLUSION

Posterior Ponte osteotomy releases produced more motion than facetectomy alone in axial rotation and sagittal correction maneuvers, but had no effect on coronal correction. Anterior discectomy release destabilized spinal column significantly more than posterior releases in all force applications. Despite ample clinical experience demonstrating the effectiveness of posterior-only surgery, the biomechanical effect of Ponte osteotomies is modest.

LEVEL OF EVIDENCE

N/A.

Treatment of severe scoliosis with posterior-only approach arthrodesis and all-pedicle screw instrumentation

PURPOSE

Posterior-only approach arthrodesis by all-pedicle screw instrumentation has a correction rate similar to correction obtained by traditional combined anterior/posterior approach surgery and avoids the complications associated with the thoracic approach.

METHODS

We treated 25 patients, with a mean age 16.5 years, with severe adolescent idiopathic scoliosis by posterior-only approach using all-screw instrumentation arthrodesis. Mean scoliosis curve in Cobb degrees was 95° Cobb. All cases were treated by the same senior surgeon, by free hand technique, without intraoperative neurophysiologic monitoring and spine navigation aids.

RESULTS

Mean scoliosis curve after surgery was 37° Cobb. Mean follow-up was 4 years. No perioperative complications, curve progression or arthrodesis malunion were reported at the follow-up.

CONCLUSIONS

Posterior spinal fusion with pedicle screw-only instrumentation obtains a good and stable correction of severe scoliosis; compared to hybrid instrumentation, it allows a greater coronal correction of the deformity and less correction loss at the follow-up.

Posterior instrumentation and fusion

The purpose of surgery for adolescent idiopathic scoliosis, which characteristically includes thoracic hypokyphosis and all three columns of the spine, is the achievement of a balanced spine while preserving as many motion segments as possible and avoiding neurologic damage. Many approaches have been defined in the treatment of this common disease. Posterior-only surgery, instrumentation and fusion have become the preferred technique in many centers throughout the world due to simplicity of approach, decreased risk of certain complications and the correction power of pedicle screws. This review attempts to summarize the advantages and disadvantages related to posterior instrumentation and fusion in adolescent idiopathic scoliosis.

The effect of posterior spinal releases on axial correction torque: a cadaver study

PURPOSE

Posterior only approaches for spinal deformity are increasingly popular and posterior spinal release is utilized to gain flexibility for correctional maneuvers. Prior biomechanical data support the use of facetectomy and rib head resection for gaining flexibility in the sagittal and coronal planes but to date there has been no quantification of stiffness reduction provided by these techniques for axial correction through a pedicle screw construct. We sought to determine the contribution of posterior spinal releases (facetectomy, rib head resection) on axial plane stiffness.

METHODS

Four fresh-frozen human cadavers were instrumented with fixed angle pedicle screws in the thoracic spine. The torque needed to produce 25° axial deflections at individual spinal segments (levels T5-T11) was measured using a custom needle deflection torque device attached to commercially available vertebral rotating construct. After the intact specimen was tested, torque measurements were repeated following a full facetectomy and posterior rib head resection

RESULTS

Complete facetectomy resulted in an 18% decrease of torque needed to produce 25° of axial deformity compared to the intact specimen (P < 0.001). Rib resection added an additional 36% decrease in torque (P < 0.001).

CONCLUSIONS

Complete facetectomies (Ponte or Smith-Petersen osteotomies) decrease the force required to rotate spinal segments with respect to the axial plane by approximately one-fifth. Posterior rib head resection should be considered to further loosen the spine if additional axial correction is desired.

Management of severe spinal deformity: scoliosis and kyphosis

STUDY DESIGN

Review of the literature and author';s experience with the treatment of severe spinal deformity.

OBJECTIVE

To define the anatomic and physiologic challenges in treating severe spinal deformity and to describe the preoperative, intraoperative, and postoperative strategies to achieve the optimal safe result.

SUMMARY OF BACKGROUND DATA

Severe pediatric spinal deformity is a relatively uncommon condition that often arises following treatment of early onset scoliosis. Patients most often present with severe clinical and radiographic deformity with poor pulmonary function. In contrast to the more common adolescent idiopathic scoliosis which is a primary spinal deformity, patients with severe spine deformity have the added chest wall deformity which may need to be addressed at the time of treatment. Previous literature has identified the challenges in the treatment of these patients and the higher risk for complications.

METHODS

A literature review and review of the author's personal experience in the treatment of these patients was performed. An assessment of the preoperative, intraoperative, and postoperative factors leading to an optimal result was analyzed and reported.

RESULTS

The early evaluation should include a multidisciplinary approach from the orthopaedic surgeon, pulmonologist, anesthesiologist, and perhaps the neurologist to provide a baseline assessment. Advanced imaging of the spine with computed tomography is useful especially when previous surgery has been performed and/or when plain radiography is limited. Magnetic resonance imaging of the spinal cord and brain stem is important to ensure that no neural axis abnormalities are present and can determine if spinal cord compression is present. Severe spinal deformity should be distinguished from the more common adolescent idiopathic scoliosis deformity in that both the spine and the chest wall are affected. Preoperative halo-gravity traction is an invaluable tool to improve the flexibility of the spine and chest, to improve pulmonary function, and to stress the spinal cord while the patient is awake and provides feedback as to the neurologic assessment. Surgical treatment should be divided into 3 phases. First, anchor placement which should be predominantly pedicle screws placed in a segmental fashion and also use of reduction screws when performing vertebral column resections. Second, steps should be performed to increase the flexibility of the spine and chest with incremental releases from simple posterior soft tissue releases to posterior facet resections, to vertebral column resections for the most severe deformity. The third phase is the correction of the spine and chest wall deformity. Many strategies can be used to correct these deformities and relies on good anchor point fixation and good releases of the spine and chest wall. Provisional rod fixation is critical when performing resection of the spine to allow for safe correction of the deformity. Improvements in the clinical and radiographic appearance, pulmonary function, and self image are often dramatic.

CONCLUSION

The treatment of severe spinal deformity is challenging and requires careful assessment of the patient by the orthopaedic surgeon, anesthesiologist, pulmonologist, and neurologist especially when neurologic deficits are present. Proper planning and execution of the correct surgical procedure for the surgeon provides an outstanding life-changing result in these patients.

Posterior-only surgery with strong halo-femoral traction for the treatment of adolescent idiopathic scoliotic curves more than 100°

The aim of this study was to investigate the feasibility and clinical efficacy of treatment of adolescent idiopathic scoliosis of >100° via posterior-only surgery with strong halo-femoral traction and posterior wide release. From December 2003 to August 2006, 121 patients with adolescent idiopathic scoliosis were treated in our hospital; among them, 29 patients with curves over 100° were included in this study. From December 2003 to June 2005, group A included the first 12 patients who underwent combined anterior release followed by two-week halo-femoral traction and then posterior instrumentation. From July 2005 to August 2006, 17 patients in group B underwent posterior surgery alone with strong halo-femoral traction and posterior wide release. All of the patients were followed-up for a minimum of 31 months (mean, 36 months; range, 31-41 months). There were no severe complications. All of the patients achieved bony fusion without instrumentation breakage or pseudarthrosis. There were no statistically significant differences between the two groups in gender, age, type of adolescent idiopathic scoliosis, preoperative coronal major curve values, major curve flexibility, or final follow-up major curve correction rate. The average operative time, blood loss and hospital stay in group B were less than those in group A. In adolescent idiopathic scoliosis with Cobb >100°, posterior-only surgery with strong halo-femoral traction and posterior wide release can provide comparable curve correction with shorter operative time, less blood loss and shorter hospital stay when compared to combined anteroposterior surgery.

Prone thoracoscopic release does not adversely affect pulmonary function when added to a posterior spinal fusion for severe spine deformity

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

To analyze the effect of adding a thoracoscopic release and fusion performed in the prone position with double lung ventilation to a posterior spinal fusion and instrumentation (PSFI) for severe idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

A prone thoracoscopic anterior release (TAR) offers the advantages of a minimally invasive approach, without requiring repositioning for the PSFI, and has significantly less acute pulmonary complications since single lung ventilation is avoided. It is unclear whether prone thoracoscopy adversely affects pulmonary function tests (PFT) when added to a PSFI for severe deformity.

METHODS

A prospective consecutive series of patients from a single institution undergoing spinal deformity surgery were reviewed. Those patients who underwent prone TAR followed by PSFI were compared to patients who had PSFI alone. In addition, those patients who had a thoracoplasty and PSF (PSFI-T) were compared to those who had a TAR and PSFI with T. (PFTs were measured before surgery and 1, 3, 6 weeks, 3 and 6 months, and 1 year after surgery. Forced vital capacity (FVC) and FE-1 parameters were compared to baseline levels for each patient. RESULTS.: There were 13 patients in the TAR + PSFI groups and 83 in the PSFI groups. The patients in the TAR + PSFI group had larger thoracic curves (83.2 degrees vs. 59.7 degrees ), greater correction (59.4% vs. 50.1%) (P = 0.07), and greater increase in thoracic height (16.4% vs. 6.8%) following surgery. (P < 0.05) PFTs declined more rapidly for the TAR + PSFI patients in the first 3 weeks, however, improved rapidly until 1 year when they were significantly better than the PSFI group for predicted FVC % (29.7% vs. 7.5% above baseline) and forced expiratory volume (FEV) 1% (28.5% and 8.9% above baseline). (P < 0.05) When a thoracoplasty was added to the procedure, the differences in PFTs between those who had a TAR and those who did not was not significant. The TAR + PSFI-T group had FVC % predicted of 5.3% above baseline compared to 4.3% above baseline for the PSFI-T group. The percent predicted FEV 1% was 10.4% above baseline for the TAR + PSFI-T group compared to 4.5% for the PSF-T group (P > 0.05).

CONCLUSION

When performing a prone thoracoscopic release for severe thoracic deformity, excellent coronal plane correction is achieved. There does not appear to be any detrimental effect on pulmonary function when a prone thoracoscopic release using double lung ventilation is added to a PSFI. This technique can be efficacious in achieving excellent deformity correction without adversely affecting pulmonary function and is recommended when treating severe spinal deformity. Adding a thoracoplasty provided a negative effect on pulmonary function and limited the benefits of performing a thoracoscopic release to the PSFI patients.

MINIMALLY INVASIVE POSTERIOR OSTEOTOMIES

OBJECTIVE

Surgery for thoracolumbar deformity can lead to significant muscle injury, excessive blood loss, and severe postoperative pain. The aim of the following studies was to determine the feasibility of minimally invasive posterior thoracic corpectomy and thoracolumbar osteotomy techniques for deformity in human cadavers and select clinical cases.

METHODS

Human cadaveric specimens were procured for thoracic corpectomy and Smith-Petersen and pedicle subtraction osteotomy using a minimally invasive approach. Post-procedural computed tomography was used to assess the degree of decompression following corpectomy and the extent of bone resection after osteotomy. Pre and post-osteotomy closure Cobb angles were measured to evaluate the degree of correction achieved.

RESULTS

The minimally invasive lateral extracavitary approach for thoracic corpectomy provided adequate exposure and allowed excellent spinal canal decompression while minimizing tissue disruption. Nearly complete osteotomies of both types could be achieved through a tubular retractor with a modest change in Cobb angle.

CONCLUSION

These techniques may play a role in deformity surgery for select cases with further technological advancements.

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

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

Adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) affects 1-3% of children in the at-risk population of those aged 10-16 years. The aetiopathogensis of this disorder remains unknown, with misinformation about its natural history. Non-surgical treatments are aimed to reduce the number of operations by preventing curve progression. Although bracing and physiotherapy are common treatments in much of the world, their effectiveness has never been rigorously assessed. Technological advances have much improved the ability of surgeons to safely correct the deformity while maintaining sagittal and coronal balance. However, we do not have long-term results of these changing surgical treatments. Much has yet to be learned about the general health, quality of life, and self-image of both treated and untreated patients with AIS.

Comparison of radiographic outcomes for the treatment of scoliotic curves greater than 100 degrees: wires versus hooks versus screws

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

To compare the efficacy and safety of several different anchors in the apical levels of scoliotic curves > or = 100 degrees using radiographic outcomes and clinical complications.

SUMMARY OF BACKGROUND DATA

To the best of our knowledge, no reports have compared various anchors at the apical level for correction of scoliosis curves > or = 100 degrees.

METHODS

Sixty-eight scoliosis patients (44 neuromuscular, 21 idiopathic, and 3 congenital) with major curves > or = 100 degrees (mean, 112.7 degrees; range, 100 degrees -159 degrees ) who underwent segmental spinal instrumentation and fusion with different anchors in the apical level were analyzed. All patients had a minimum 2-year follow-up (mean, 4.0 years; range, 2.0-10.5) and were divided into Group W (sublaminar wires n = 26), Group H (hooks n = 18), Group A (anterior vertebral screws n = 7), and Group PS (pedicle screws n = 17) based on the type of apical anchor used. Radiographic parameters and complications were investigated.

RESULTS

The 4 groups did not demonstrate any significant differences in gender, age at surgery, preoperative major Cobb angle, or curve flexibility (all P > 0.05). However, the PS group demonstrated a shorter follow-up period compared with the other 3 groups (P < 0.05). The PS group demonstrated the greatest correction rate, smallest loss of correction (P < 0.05), and greatest amount of correction of the apical vertebral translation (P < 0.0005) at ultimate follow-up. There were 4 cases (5.9%) of pseudarthrosis (3 in Group W, 1 in Group H; P > 0.05), 6 cases (8.8%) of implant failure (4 in Group W, 2 in Group H; P > 0.05). Despite one (1.5%) intraoperative neurologic complication (differences among groups, P > 0.05), there was no permanent neurologic deficit.

CONCLUSION

All 4 constructs were able to achieve and maintain acceptable correction safely without permanent neurologic deficit and all demonstrated acceptable implant failure rate. Pedicle screw constructs in the apical levels demonstrated the best coronal correction, smallest loss of correction, and greatest amount of apical vertebral translation correction of the major Cobb angle compared with the other constructs without neurologic complications.

Developing outcome measures for pediatric deformity surgery

STUDY DESIGN

: Review article regarding the development of outcome measures for pediatric spinal deformity.

OBJECTIVE

: To discuss the role of patient-based outcomes and process measures in pediatric spinal deformity patients.

SUMMARY OF BACKGROUND DATA

: A number of health-related quality of life (HRQOL) questionnaires assess, from patients' perspectives, the effectiveness of spinal deformity correction. The SRS instrument is the most prominent HRQOL tool used in North American adolescent scoliosis studies today. However, these patient-based outcomes and perceptions do not necessarily correlate with process measurements, particularly in the area of increase spinal deformity correction being achieved with newer, more powerful, pedicle screw instrumentation. Furthermore, spinal deformity presenting during infancy or early childhood poses a particular challenge for developing useful evidence-based outcomes tools.

METHODS

: The rationale for patient-based outcome development in pediatric spinal deformity is discussed, along with its important association with process measures.

RESULTS

: Newer HRQOL tools are under development that may better recognize and differentiate changes in adolescent patients' appearances before and after surgery. For early-onset spinal deformity patients, newer process measures for periodic outcome assessment, such as volume measurement of lung parenchyma and spine/chest cage measurement, are being developed.

CONCLUSION

: Ultimately, both patient and process measures are necessary to fully evaluate the results of pediatric spinal deformity surgery.

The Scoliosis Research Society classification for adult spinal deformity

The management of adult spinal deformity is characterized by significant variability in operative and nonoperative approaches. Adult spinal deformity encompasses a broad spectrum of disorders of the spine, and the disparity observed in reported clinical outcomes of operative and nonoperative care reflects the heterogeneity of the cases studied. A classification of spinal deformity in adults is important in providing a framework for comparison of similar cases and for reporting outcomes on well-defined disorders. Existing classifications of scoliosis are limited in their applicability to adult deformity because they do not include parameters of lumbar degenerative change and regional sagittal alignment that are critical to decision making in surgical care of the adult. The Scoliosis Research Society classification for adult deformity is presented in this article. The purpose of this classification is to provide a framework for reporting similar cases and to contribute to the development of an evidence-based approach to the management of adult spinal deformity.

Adolescent idiopathic scoliosis: Lenke type I-VI case studies

Brace treatment is effective for selected patients with AIS, but when patients mature or curves progress beyond 40 degrees , surgery may be discussed with the patient and family. The advent of third-generation spinal instrumentation with pedicle screw systems has made extraordinary corrections possible. These posterior corrections must be done cautiously, however. When selecting the fusion level, one should always look at the sagittal plane and include any kyphotic segments. The authors evaluate case examples of Lenke type I through type VI curves with illustrations and radiographic images in this additional content, which is only found on-line.

Surgical Strategies and Choosing Levels for Spinal Deformity: How High, How Low, Front and Back

The purpose of this article is to describe general strategies in the surgical treatment of adolescent and adult scoliosis, including radiographic evaluation, curve selection, principles guiding the selection of the upper and lower instrumented vertebrae, and indications for anterior surgery. Sagittal plane deformity, including Scheuermann's kyphosis, is discussed. Avoidance and treatment of postoperative flatback deformity is also briefly mentioned. There are multiple and sometimes conflicting considerations that must be reviewed when planning surgical stabilization of spinal deformity. Although there may be significant variation in surgeon decision making, careful adherence to primary principles, such as achieving coronal and sagittal balance in all patients and minimizing fusion levels, particularly in young patients, should be of paramount importance.

Video-assisted thoracoscopic surgery in idiopathic scoliosis: evaluation of the learning curve

STUDY DESIGN

Retrospective review of patients with idiopathic scoliosis who underwent same-day or staged anterior and posterior spinal fusion and segmental spinal instrumentation.

OBJECTIVE

Evaluation of our learning curve with video-assisted thoracoscopic surgery (VATS) with respect to operative time, blood loss, and complications in patients with idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

VATS is a minimally invasive alternative to thoracotomy in the management of idiopathic scoliosis. An increased or steep learning curve has been described in the initial application of this technique.

METHODS

We began performing VATS in 1998. We compared our first 25 consecutive VATS patients (Group 2) and subsequent 28 consecutive VATS patients (Group 3) to our previous 16 consecutive patients (Group 1) with a thoracotomy (1991-1998) for idiopathic scoliosis. Training at a sponsored regional course was obtained before performing our first VATS procedure.

RESULTS

VATS allowed more disc to be excised in Group 2 (4.5 +/- 1, 5.7 +/- 1, and 4.4 +/- 1 discs in Group 1, Group 2, and Group 3, respectively) and significantly decreased the anterior operative time (215 +/- 33, 260 +/- 56, and 177 +/- 47 minutes) and time per individual disc excision (50 +/- 13, 47 +/- 12, and 41 +/- 12 minutes), while providing comparable correction of the thoracic deformity (67% +/- 12%, 66% +/- 10%, and 70% +/- 13% correction). There was no increase in estimated intraoperative anterior blood loss (228 +/- 213, 183 +/- 136, and 211 +/- 158 mL), estimated blood loss per disc excised (51 +/- 42, 34 +/- 29 and 48 +/- 37 mL), or complications in the VATS groups. Complications were primarily pulmonary and resolved with medical therapy. Postoperative chest tube drainage (855 +/- 397, 462 +/- 249, and 561 +/- 261 mL) and total perioperative anterior blood loss (1083 +/- 507, 647 +/- 309, and 773 +/- 308 mL) were significantly decreased in the VATS groups, but this was attributed to the use of Amicar.

CONCLUSIONS

VATS is an effective procedure for anterior spinal fusion in idiopathic scoliosis. The learning curve is short, provided appropriate training is obtained.

A Large Adolescent Idiopathic Scoliosis Curve in a Skeletally Immature Patient: Is Early Surgery the Correct Approach?

The goal of this study was to determine whether the available studies provide enough evidence that, in a borderline case of adolescent idiopathic scoliosis with a large (35 to 50 degrees) curve in a skeletally immature patient (Risser 0 to 2) with significant growth potential left, a conservative line of management in the form of bracing can be considered, rather than to rush into a potentially unnecessary major spinal surgery. We reviewed the literature spanning the last 20 years for the results of bracing in this specific group of patients. From the 9 studies selected, a group-specific data extraction was carried out. Three hundred and five patients with a 36 to 50 degrees scoliosis curve and Risser stages 0 to 2 were treated by bracing and the treatment was termed successful in 160 patients. Thus, more than half (52.5%) of the patients were successfully managed with a brace and were spared surgery. The current trend for management of these curves is early surgical intervention, the rationale being the ineffectiveness of bracing in preventing the progression of such a large curve and the difficulty in obtaining satisfactory correction by postponing surgery to a later date. On the basis of our results, we propose a conservative line of management for these curves, in contrast with current views, rather than to rush into a major spine surgery, expecting a favorable outcome with a well-supervised bracing program. If the curve progresses, surgery can always be considered later, keeping in mind the excellent correction obtained with the pedicle screw systems even for large curves of 70 to 100 degrees.

Is there a need for anterior release for 70-90 degrees masculine thoracic curves in adolescent scoliosis?

Large and stiff thoracic scoliotic curves in the adolescent represent a classic indication of anterior release followed by posterior instrumentation. However, third-generation segmental spinal instrumentations have shown increased correction of thoracic curves. Indication for an anterior release may therefore not be required even in large and stiff thoracic curves. The objective of the study was, therefore, to analyze retrospectively the results of third-generation segmental posterior instrumentation in large and stiff thoracic curves and to compare our results with the current literature of anterior release followed by posterior instrumentation. An independent observer, who had not participated in any of the case, reviewed our electronic database of adolescent scoliosis surgery (Scolisoft) with the following query: thoracic curves, Cobb angle between 70 degrees and 90 degrees and posterior surgery only. He was able to identify 19 patients whose thoracic curves were measured between 70 degrees and 90 degrees . Out of these, four had convex-side bending Cobb angle values of less than 45 degrees and were not included in the study, as they were judged too flexible. Fifteen patients (aged 11-18 years, mean 13.6 years) with thoracic scoliosis were left for the study (average Cobb angles 78.5 degrees with a flexibility index of 32.5% (range, 19-42%). The mean follow-up period was 32 months (range 18-64 months). Classic parameters of deformity correction were analysed. The average operative time was 314 min and the mean total blood loss was 1,875 ml. Average level of instrumented vertebrae was 12 (Range, 10-14). Postoperatively, the thoracic Cobb angle was measured at 34.8 degrees (range, 25-45 degrees ), which represents a correction rate of 54% (range, 40.0-67.1%) and remained unchanged at the last follow-up (35 degrees ). Patients with thoracic hypokyphosis improved from an average 11 degrees to 18 degrees . There were three complications (one excessive bleeding, one early infection and one late infection). One case showed an add-on phenomenon at the last follow-up. Coronal balance was improved from 1.8 cm (Range 0-4 cm) down to 0.75 cm (range 0-2.5 cm). Shoulder balance was improved from 1.3 cm (range 0-4 cm) down to 0.75 (0-2.5 cm). All patients reported satisfactory results except the patient with an adding-on phenomena. In the literature, most of the results of anterior thoracoscopic release and posterior surgery give a percentage of Cobb angle correction similar or inferior to our series for an average initial Cobb angle of less magnitude. Therefore, with adequate posterior release, and the use of third-generation segmental instrumentation there is no need for anterior release even for curves in the 70-90 degrees range.