Do Ponte Osteotomies Enhance Correction in Adolescent Idiopathic Scoliosis? An Analysis of 191 Lenke 1A and 1B Curves

Osteotomies at the Time of Graduation Surgery: How Much Do We Get From Them?

STUDY DESIGN

Retrospective, multicenter.

OBJECTIVE

Determine if posterior column osteotomies (PCO) at time of conversion from growth friendly instrumentation (GFI) to definitive fusion in early onset scoliosis (EOS) graduates impacts outcomes.

SUMMARY OF BACKGROUND DATA

Increasing spinal rigidity following treatment of EOS with GFI can limit curve correction at time of conversion to definitive spinal fusion. PCO are often employed at the time of fusion to improve flexibility. This technique's efficacy has not been studied.

METHODS

Patients with EOS with GFI undergoing conversion to fusion were grouped by those that did or did not have PCO. Patients with inadequate radiographs, <2 years follow-up, or three-column osteotomies at time of fusion were excluded.

RESULTS

Eight hundred thirty-two patients met inclusion criteria. One hundred seventy-five (21%) patients had PCO. Age at index surgery was younger (6.6 vs . 7.4 y, P =0.0009), and the mean duration of GFI was greater (6.2 vs. 5.5 y, P =0.009) in the PCO group. Before fusion, curve magnitude was similar between the groups (PCO=61.9°, no PCO=59.3°, P =0.18). On average 4.4 osteotomies (range: 1-12) were performed for the PCO group and EBL (PCO=820 cc vs . no PCO=752 cc, P <0.01) and surgical time (PCO=403 min vs . no PCO=349 min, P <0.01) were greater. Postoperatively, mean curve correction (PCO=16.6°, no PCO=14.4°, P =0.18) was similar. Accounting for preoperative curve magnitude, there was a relationship between number of PCOs and curve correction ( P =0.04). There was no relationship between degrees of correction per osteotomy and duration of GFI ( P =0.12). Postoperative complications at 2 years were similar (PCO=25% vs. no PCO=27%, P =0.63).

CONCLUSIONS

EOS graduates achieve minimal correction at time of conversion regardless of whether PCOs are performed. PCOs increase EBL and operative time but have a similar complication rate. More PCOs resulted in more correction, though less than that anticipated in a previously uninstrumented spine.

LEVEL OF EVIDENCE

III.

Techniques of Deformity Correction in Adolescent Idiopathic Scoliosis-A Narrative Review of the Existing Literature

Surgical management of adolescent idiopathic scoliosis [AIS] is a complex undertaking with the primary goals to correct the deformity, maintain sagittal balance, preserve pulmonary function, maximize postoperative function, and improve or at least not harm the function of the lumbar spine. The evolution of surgical techniques for AIS has been remarkable, transitioning from rudimentary methods of spinal correction to highly refined, biomechanically sound procedures. Modern techniques incorporate advanced three-dimensional correction strategies, often leveraging pedicle screw constructs, which provide superior rotational control of the vertebral column. A number of surgical techniques have been described in the literature, each having its own pros and cons. This narrative review provides a detailed analysis of the contemporary surgical techniques used in the treatment of patients with AIS.

The Technique of a Modified Ponte Osteotomy Using Ultrasonic Bone Scalpel in Spinal Deformity Correction: Does It Save Time and Reduce Blood Loss?

Background and objective Posterior column osteotomies, such as Smith-Petersen and Ponte osteotomies, are widely utilized in the surgical correction of spinal deformities to address sagittal and coronal imbalances by releasing the posterior tension band. While traditional methods using rongeurs and osteotomies are effective, these are often associated with prolonged operative time, significant blood loss, and increased risk to neural structures. These challenges have driven interest in advanced tools like the ultrasonic bone scalpel (UBS), which uses high-frequency vibrations to enable precise bone cutting with minimal damage to surrounding tissues. This innovative tool has demonstrated significant reductions in blood loss and operative time in various spinal procedures. However, its specific application in modified Ponte osteotomies remains underexplored. This study evaluates the UBS's safety, efficiency, and impact on blood loss in complex deformity corrections and presents a refined technique for optimizing outcomes in these challenging surgeries. Additionally, it outlines a refined technique for executing modified Ponte osteotomies with this advanced tool. Methods This retrospective study included all patients who underwent spinal deformity surgery involving modified Ponte osteotomy with a UBS between January 2013 and June 2022. Key metrics analyzed included the number of modified Ponte osteotomy segments performed per surgery, the total time taken for osteotomies, and the average time required per segment. Blood loss was evaluated with a focus on epidural and bony sources, and methods for controlling bleeding were documented. Safety parameters included intraoperative neurophysiological signal integrity and the incidence of dural tears. Results A total of 695 modified Ponte osteotomy segments were performed in 111 patients undergoing complex spinal deformity correction surgery. The average number of segments created per procedure was 6.26 ± 1.59 (range: three to nine). The mean operative time required for all segments per surgery was 19.16 ± 5.66 minutes, with an average time of 3.05 ± 0.29 minutes per segment (range: 2.13-4.66 minutes). Epidural bleeding was observed at an average of 1.65 ± 1.27 points per surgery (range: 0-6), equating to 0.26 ± 0.20 points per segment. Bleeding was effectively controlled with bipolar ablation and absorbable gelatin sponge packing, and no significant bony bleeding was reported. Of note, there were no instances of intraoperative neuromonitoring signal loss or dural tears, demonstrating the safety of the technique. No splinters occurred while osteotomizing in any case. Conclusions The use of UBS significantly enhances the efficiency and safety of modified Ponte osteotomy during spinal deformity correction surgeries. This technique not only reduces operative time but also minimizes blood loss, offering an advanced approach to achieving precise osteotomies without compromising patient safety. These findings underscore the benefits of incorporating UBS into complex spinal surgical procedures.

Optimising deformity correction: a retrospective comparative analysis of two techniques in high magnitude curves in adolescent idiopathic scoliosis

STUDY DESIGN

A retrospective comparative study.

PURPOSE

To validate the hypothesis that a combination of multilevel Ponte osteotomy (PO) with intraoperative traction (IOT) results in a better correction than IOT alone in high-magnitude curves in adolescent idiopathic scoliosis (AIS) and does not possess an attributable risk of neurological injury.

OVERVIEW OF LITERATURE

On a comprehensive review of the literature, the choice of technique adopted for curves between 65° and 100° remains controversial with no major consensus favoring one technique over the other.

METHODS

Twenty-four patients with AIS (Cobb >65°) underwent surgery at a single center between January 2014 and December 2021. The first 10 patients underwent surgery using only IOT (T group), whereas the subsequent 14 patients underwent surgery with a combination of IOT and PO (TP group).

RESULTS

The mean preoperative Cobb angles in the T and TP groups were 89.35°±6.05° and 92.32°±9.28°, respectively (p=0.59). The mean flexibility index (FI) of the T and TP groups were 0.31±0.016 and 0.36±0.03, respectively (p=0.41). The mean postoperative Cobb angle in the T and TP groups were 40.25°±5.95° and 19.1°±3.20°, respectively (p=0.041). Apical vertebral rotation improved from mean grade 3.2 (2-4) to grade 2.6 (1-3) in the T group and from mean grade 3.6 (2-4) to mean grade 1.8 (1-3) in the TP group. Postoperatively, the mean thoracic kyphosis was 13.84°±2.10° and 21.02°±1.68° in T and TP groups (p=0.044). Transient signal-loss intraoperatively was noted in two patients, one in each group. No episodes of postoperative neurological deficits were reported. No incidences of pseudarthrosis/implant-related complications were reported at the end of 2 years in either group.

CONCLUSIONS

IOT and PO complement one another and can be safely combined without an attributable risk of neurological injury.

Ponte osteotomies for treatment of spinal deformities: they are not all made equal

PURPOSE

To compare surgical outcomes of Ponte's osteotomies for treatment of adolescent idiopathic scoliosis (AIS), Scheuermann's kyphosis (SK), and adult scoliosis (AdS).

METHODS

We conducted a retrospective review of patients with AIS, SK, and AdIS who underwent posterior spinal instrumented fusion (PSIF) at our Institution from January 2019 to December 2022. Demographics, imaging, and intraoperative data (including number of osteotomies performed, blood losses, surgical timing, and complications) were extracted from patient charts.

RESULTS

A total of 80 patients (62 AIS, 7 SK, and 11 AdS) were enrolled in the study. All patients were treated with a PSIF and a total of 506 Ponte osteotomies were performed (5.8 ± 4.1, 9.3 ± 2.4, and 7.5 ± 2.5 average osteotomies per patient in the AIS, SK, and AdS group, respectively; p = 0.045). Average time per osteotomy was 6.3 ± 1.5 min in the AIS group, and 5.8 ± 2.1 and 8.7 ± 4.0 in the SK and AdS group, respectively (p = 0.002). Blood loss was significantly smaller in the SK group (8.6 ± 9.6 ml per osteotomy) compared to AIS group (34.9 ± 23.7 ml) and AdS group (34.9 ± 32.7 ml) (p = 0.001). A total of 4 complications were observed in the AIS group (1.1%) and 2 complications in the AdS group (2.4%), but this was not statistically significant.

CONCLUSIONS

Our study shows that Ponte's osteotomies are safe and effective in surgical treatment of AIS, SK, and AdS. Blood loss and execution time per osteotomy are significantly smaller in the SK group compared to AIS and AdS. No significant differences were noted in terms of complications between the three groups.

Effectiveness of Facetectomy in Correction of Adolescent Idiopathic Scoliosis

INTRODUCTION

 Surgical correction of adolescent idiopathic scoliosis (AIS) using the facetectomy technique with the utilization of segmental pedicle screws aims to achieve correction of coronal and sagittal imbalances and preserve normal neurological function. In this study, we aimed to certify the effectiveness of the facetectomy technique in the correction of AIS by analyzing technique outcomes.

METHODS

This is a retrospective, single-center study. From January 2018 to March 2022, a total of 51 patients with AIS who underwent inferior facetectomy with segmental pedicle screw constructs at the Royal Rehabilitation Center were reviewed. Radiological parameters including the major curve Cobb angle, and global coronal balance were evaluated preoperatively, postoperatively, and at the final follow-up. Surgical parameters and complications were also reported.

RESULTS

The mean major curve Cobb angle was 59.5 ± 4.9° preoperatively, 13.6 ± 2.7° postoperatively, and 14.5 ± 2.6° at the final follow-up, with correction rates of 77.2% and 75.7%, respectively. The mean global coronal balance was 2.7 ± 1.1 cm preoperatively, 1.7 ± 0.73 cm postoperatively, and 1.4 ± 0.55 cm at the final follow-up. Two cases of pleural injuries were reported intraoperatively. Postoperatively, two cases experienced superficial wound infections, one experienced pulmonary embolism, and one patient had revision surgery due to the loosening of a single screw. None of these complications lasted long.

CONCLUSIONS

When combined with posterior segmental pedicle screw constructs, inferior facetectomy can provide an effective rate of correction in a reasonably safe manner.

Ponte Osteotomies in the Surgical Treatment of Adolescent Idiopathic Scoliosis: A Systematic Review of the Literature and Meta-Analysis of Comparative Studies

The purpose of the present paper is to assess if Ponte osteotomies (POs) allow for a better correction in adolescent idiopathic scoliosis (AIS) surgery and to investigate their safety profile. A systematic search of electronic databases was conducted. Inclusion criteria: comparative studies that reported the outcomes of AIS patients who underwent surgical correction through posterior-only approach with and without POs. Clinical and radiographic outcomes were extracted and summarized. Meta-analyses were performed to estimate the differences between patients treated with and without POs. p < 0.05 was considered significant. In total, 9 studies were included. No significant difference in thoracic kyphosis (TK) change between patients treated with and without POs was found (+3.8°; p = 0.06). Considering only hypokyphotic patients, a significant difference in TK change resulted in POs patients (+6.6°; p < 0.01), while a non-significant TK change resulted in normokyphotic patients (+0.2°; p = 0.96). No significant difference in coronal correction (2.5°; p = 0.10) was recorded. Significant estimated blood loss (EBL) (142.5 mL; p = 0.04) and surgical time (21.5 min; p = 0.04) differences were found with POs. Regarding complications rate, the meta-analysis showed a non-significant log odds ratio of 1.1 (p = 0.08) with POs. In conclusion, POs allow for the restoration of TK in hypokyphotic AIS, without a significantly greater TK change in normokyphotic patients, nor a significantly better coronal correction. Considering the significantly greater EBL and the trend toward a higher complications rate, the correct indication for POs is crucial.

No short-term clinical improvement and mean 6° of thoracic kyphosis correction using limited-level Ponte osteotomy near T7 for Lenke type 1 and 2 adolescent idiopathic scoliosis: a preliminary study

This study was a retrospective single surgeon case series approved by institutional review board and showed the efficacy of limited Ponte osteotomy at T6/7, 7/8 and 8/9 (limited-PO) in the sagittal plane for patients with Lenke type 1 and 2 adolescent idiopathic scoliosis (AIS). A total of 37 consecutive patients [7 males and 30 females; average age 16.0 ± 2.5 (range: 12-21)] over a 4-year period with posterior corrective fusion surgery were included. Initially, 18 patients were operated on without limited-PO [P(-)-group]. Midway in the series, the senior author switched to the limited-PO [P(+)-group]. The limited-PO has been performed to form the apex of thoracic kyphosis at the T7 level, together with the restoration of thoracic kyphosis. The mean amount of the correction angle of thoracic kyphosis was more in the P(+)-than in P(-)-group (13.8 ± 9.6° vs. 7.8 ± 8.0°, P  = 0.046) at 1-year after surgery. Cervical lordosis was spontaneously corrected more in P(+)-than in P(-)-group. The apex of thoracic kyphosis was controlled around the T7 level postoperatively in most cases (18/19 cases). There was no significant difference between the two groups in terms of blood loss and operative time per level, or Scoliosis Research Society-22 domain scores. Limited-PO contributed to the restoration of the whole spinal sagittal alignment for Lenke type 1 and 2 AIS; however, in this preliminary study, the clinical improvement was unclear at least in the short term, because the kyphosis angle obtained by limited-PO was only approximately 6°.

Correction of severe adult idiopathic scoliosis posteriorly with skipped pedicle screw instrumentation and rod augmentation

BACKGROUND

Although it is challenging to correct severe adult idiopathic scoliosis (ADIS) deformities, optimal results can be achieved by multiple asymmetric Ponte osteotomies with lower surgical risks. Skipping the apical instrumentation and using multiple rods and connectors may further facilitate the procedure. We named this method as "modular correction technique" (MCT).

METHODS

Sixty-two patients with severe ADIS who were treated with MCT were recruited into this study, and retrospectively evaluated. Radiographic and functional outcomes as well as pulmonary functions were examined preoperatively and at last follow-up. Main radiologic parameters were related to Cobb angles, coronal, sagittal, and shoulder balance. Scoliosis Research Society-22 questionnaire and the Oswestry Disability Index were used to evaluate clinical outcomes.

RESULTS

Average age of the patients was 41.3 years (range: 23-65). Thirty-nine of the patients were female and 23 of them were male. Coronal Cobb angle of the main curve, shoulder balance, coronal, and sagittal balance significantly improved after the surgery. Forced vital capacity and forced expiratory volume in the first second were mildly improved after the surgery, however the improvement was not statistically significant. Postoperative clinical outcome scores improved significantly.

CONCLUSION

MCT can be performed with low risk of complications and relatively low operation time and blood loss. It facilitates rod insertion and correction maneuvers. Radiologic, especially coronal balance, and functional outcomes can be improved with minimal morbidity while deterioration of pulmonary function is prevented. This technique is useful in severe but relatively flexible ADIS deformities.

A comparison of intervertebral ligament properties utilized in a thoracic spine functional unit through kinematic evaluation

Ligament properties in the literature are variable, yet scarce, but needed to calibrate computational models for spine clinical research applications. A comparison of ligament stiffness properties and their effect on the kinematic behavior of a thoracic functional spinal unit (FSU) is examined in this paper. Six unique ligament property sets were utilized within a volumetric T7-T8 finite element (FE) model developed using computer-aided design (CAD) spinal geometry. A 7.5 Nm moment was applied along three anatomical planes both with and without costovertebral (CV) joints present. Range of Motion (RoM) was assessed for each property set and compared to published experimental data. Intact and serial ligament removal procedures were implemented in accordance with experimental protocol. The variance in both kinematic behavior and comparability with experimental data among property sets emphasizes the role nonlinear characterization plays in determining proper kinematic behavior in spinal FE models. Additionally, a decrease in RoM variation among property sets was exhibited when the model setup incorporated the CV joint. With proper assessment of the source and size of each ligament, the material properties considered here could be expanded and justified for implementation into thoracic spine clinical studies.

One stage correction via the Hi-PoAD technique for the management of severe, stiff, adolescent idiopathic scoliosis curves > 90°

STUDY DESIGN

Retrospective cohort study.

PURPOSE

to assess the efficacy and safety of Hi-PoAD technique in patients with a major thoracic curve > 90°, < 25% of flexibility and deformity spread over more than five vertebral levels.

METHODS

retrospective review of AIS patients with a major thoracic curve (Lenke 1-2-3) > 90°, with < 25% of flexibility and deformity spread over more than five vertebral levels. All were treated via the Hi-PoAD technique. Radiographic and clinical score data were collected pre-operatively, operatively, at 1 year, 2 years and at last follow-up (2 years minimum).

RESULTS

19 patients were enrolled. A 65.0% correction rate of the main curve was achieved, from 101.9° to 35.7° (p < 0.001). The AVR reduced from 3.3 to 1.3. The C7PL/CSVL reduced from 1.5 to 0.9 cm (p = 0.013). Trunk Height increased from 31.1 to 37.0 cm (p < 0.001). At the final follow-up no significant changes, except from an improvement in C7PL/CSVL (from 0.9 cm to 0.6 cm; p = 0.017). SRS-22 increased in all patients, from 2.1 to 3.9 at 1 year of follow-up (p < 0.001). 3 patients had a transient drop of MEP and SEP during maneuver and were managed with temporary rods and a second surgery after 5 days. 2 of these 3 cases (66.7%) had a Total-Deformity Angular Ratio (T-DAR) > 25; conversely, among patients who had a one-stage procedure, only 1 (6.2%) had a T-DAR > 25 (p = 0.008).

CONCLUSIONS

The Hi-PoAD technique proved to be a valid alternative for the treatment of severe, rigid AIS involving more than 5 vertebral bodies.

STUDY DESIGN

Retrospective comparative cohort study.

LEVEL OF EVIDENCE

III.

Direct Vertebral Rotation (DVR) Does Not Improve Clinical and Radiological Results Compared to Differential Rod Contouring (DRC) in Patients Treated Surgically for Idiopathic Scoliosis

Direct vertebral rotation (DVR) is the most widespread method to correct axial vertebral rotation. Differential rod contouring (DRC) also includes derotation, but not to the same extent as DVR. DVR requires additional surgical effort with potential consequences, which are absent in DRC; moreover, the data concerning the clinical benefits of apical derotation are not convincing. In the present study, clinical and radiological outcomes were compared in patients who underwent surgery for adolescent idiopathic scoliosis (AIS), having DVR and DRC vs. DRC only. In total, 73 AIS patients with curves of 40-85°, consecutively operated on by one surgeon, participated in this study and were followed up over 2 years. Scores from the SRS-22 questionnaire were analysed, the angles of trunk rotation (ATR) were measured with an inclinometer and a radiographic assessment of coronal and sagittal spinal profiles was conducted. In 38 cases, only DRC was performed, and in 35 DRC was performed and followed by DVR; the groups did not differ from an epidemiological point of view. Total SRS-22 scores after 2 years were similar in both groups (4.23 (±0.33) in DRC vs. 4.06 (±0.33) in DRC/DVR, p = 0.1). In all components of SRS-22, the differences were minor, with p being way above 0.05. The mean ATR in the DRC/DVR group was slightly smaller (8 ± 4°) than that of the DRC group (10 ± 5°), p = 0.16. Radiographic analysis did not show significant differences. The coronal curve was corrected by 66 ± 12% for DRC and 63 ± 15% for DVR, p = 0.28. Thoracic kyphosis in the DRC/DVR group increased by 1°, whereas in the DRC group the average kyphosis increased by 5° with a p value of 0.07. The complication rates were similar in both groups. This investigation did not show any advantages of the combination of DRC and DVR in scoliosis correction over DRC only, both radiologically and clinically, yet it affected intraoperative parameters, extending the operation time with only a minor increase in blood loss.

Patient and surgical predictors of 3D correction in posterior spinal fusion: a systematic review

BACKGROUND

Restoration of three-dimensional (3D) alignment is critical in correcting patients with adolescent idiopathic scoliosis using posterior spinal fusion (PSF). However, current studies mostly rely on 2D radiographs, resulting in inaccurate assessment of surgical correction and underlying predictive factors. While 3D reconstruction of biplanar radiographs is a reliable and accurate tool for quantifying spinal deformity, no study has reviewed the current literature on its use in evaluating surgical prognosis.

PURPOSE

To summarize the current evidence on patient and surgical factors affecting sagittal alignment and curve correction after PSF based on 3D parameters derived from reconstruction of biplanar radiographs.

METHODS

A comprehensive search was conducted by three independent investigators on Medline, PubMed, Web of Science, and Cochrane Library to obtain all published information on predictors of postoperative alignment and correction after PSF. Search items included "adolescent idiopathic scoliosis," "stereoradiography," "three-dimensional," "surgical," and "correction." The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool, and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations approach. 989 publications were identified, with 444 unique articles subjected to full-text screening. Ultimately, 41 articles were included.

RESULTS

Strong predictors of better curve correction included preoperative normokyphosis (TK > 15°), a corresponding rod contour, intraoperative vertebral rotation and translation, and upper and lower instrumented vertebrae selected based on sagittal and axial inflection points. For example, for Lenke 1 patients with junctional vertebrae above L1, fusion to NV-1 (1 level above the neutral vertebra) achieved optimal curve correction while preserving motion segments. Pre-op coronal Cobb angle and axial rotation, distal junctional kyphosis, pelvic incidence, sacral slope, and type of instrument were identified as predictors with moderate evidence. For Lenke 1C patients, > 50% LIV rotation was found to increase spontaneous lumbar curve correction. Pre-op thoracolumbar apical translation and lumbar lordosis, Ponte osteotomies, and rod material were found to be predictors with low evidence.

CONCLUSIONS

Rod contouring and UIV/LIV selection should be based on preoperative 3D TK in order to achieve normal postoperative alignment. Specifically, Lenke 1 patients with high-lying rotations should be fused distally at NV-1, while hypokyphotic patients with large lumbar curves and truncal shift should be fused at NV to improve lumbar alignment. Lenke 1C curves should be corrected using > 50% LIV rotation counterclockwise to the lumbar rotation. Further investigation should compare surgical correction between pedicle-screw and hybrid constructs using matched cohorts. DJK and overbending rods are potential predictors of postoperative alignment.

Do hypokyphotic adolescent idiopathic scoliosis patients treated with Ponte osteotomy obtain a better clinical efficacy? A preliminary retrospective study

Study design

A retrospective case–control study.

Objective

To evaluate whether Ponte osteotomy improves thoracic kyphosis and to determine its clinical efficacy in hypokyphotic adolescent idiopathic scoliosis (AIS).

Methods

Eighty consecutive Lenke type 1 AIS patients with hypokyphotic curves who underwent posterior spinal fusion by one spine surgeon at a single institution were recruited. According to whether Ponte osteotomy was performed, the patients were divided into two groups. The preoperative, immediate, one-year postoperative, and two-year postoperative radiographs were analyzed. The demographic characteristics, surgical information, radiographic parameters, Scoliosis Research Societye-22 (SRS-22) questionnaire, and complications were compared.

Results

The sagittal alignment and coronal alignment were both improved in the Ponte group and the control group postoperatively. There was no significant difference in the preoperative parameters between the two groups, except the TL/L, CB, and LL. Significant differences were found in the MT (15.18° ± 2.84° vs. 20.33° ± 3.75°, P < 0.001) and TK (24.23° ± 2.71° vs. 19.93° ± 2.38°, P < 0.001) at the two-year follow-up. The Ponte group had a longer operation time and more intraoperative blood loss. No significant difference was observed between the groups in the SRS-22 scores at the final follow-up.

Conclusions

Ponte osteotomy could obtain better coronal correction and sagittal contour restoration in AIS patients with hypokyphosis. However, Ponte osteotomies might lead to more intraoperative blood loss and longer operation time. Moreover, no discrepancy was found in the postoperative health-related quality of life of the included patients. Therefore, we considered that the Ponte osteotomy may be an alternative method to restore the desired thoracic kyphosis, which needs further study.

Complication risks and costs associated with Ponte osteotomies in surgical treatment of adolescent idiopathic scoliosis: insights from a national database

PURPOSE

Risks of Ponte osteotomies (POs) used for posterior spinal fusion (PSF) for Adolescent Idiopathic Scoliosis (AIS) are challenging to assess because of the rarity of complications. Using a national administrative claims database, we evaluated trends, costs and complications associated with PO used in PSF for AIS patients.

METHODS

Using ICD-9/CPT codes, we identified patients (ages 10-18) with AIS who underwent PSF (± PO) between 2007 and 2015 in the IBM® MarketScan® Commercial Databases. Costs and trends of POs were evaluated. Odds of neurological complications and readmissions within 90 days and reoperations within 90 days and 2 years were assessed.

RESULTS

We identified 8881 AIS patients who had undergone PSF, of which 8193 had 90-day follow-up and 4248 had 2-year follow-up. Overall, 28.8% had PO. Annual rate of POs increased from 17.3 to 35.2% from 2007 to 2015 (p < 0.001). Risk-adjusted multivariable logistic regression demonstrated no relationship between POs and neurologic complications (p = 0.543). POs were associated with higher odds for readmission (1.52 [1.21-1.91]; p < 0.001) and reoperation (2.03 [1.13-3.59]; p = 0.015) within 90 days, but there were no differences in the odds of reoperation within 2 years (p = 0.836). Median hospital costs were $15,854 (17.4%) higher for patients with POs (p < 0.001) and multivariable modeling demonstrated POs to be an independent predictor of increased costs (p < 0.001).

CONCLUSION

Annual rate of POs increased steadily from 2007 to 2015. POs were not associated with increased odds of neurological complications but had higher costs and higher rates of readmissions and reoperations within 90 days. By 2 years, differences in reoperation rate were not significant.

LEVEL OF EVIDENCE

III.

The Effect of Ponte Osteotomies on the Sagittal Shape of Rods and Spine Derotation in Adolescent Idiopathic Scoliosis: A Single-Center, Retrospective Cohort Study

Background

Adding a Ponte osteotomy (PO) to other surgical techniques for correcting adolescent idiopathic scoliosis (AIS) profoundly affects the entire sagittal shape of the rod. POs are an effective procedure for correcting thoracic hypokyphosis in patients with AIS.

Methods

A retrospective review of 40 patients with AIS was conducted. The sample was divided into 2 groups: PO and non-PO. On a lateral radiograph, the rod end angle (A) was calculated using the intersections of the tangents with the rod end points. The maximal deflection (D) was obtained for each rod. In addition, the rod apex angle (B) was calculated using the intersection of the tangents at 2 points, each 1 cm to 1 side of the rod apex; the distance between the rods at the apex was then measured.

Results

Concave rods tended to be straight or even lordotic at the apex in the non-PO group (−0.9° vs. +5.9° in the PO group; P = 0.000). The rod end angle and deflection were significantly lower in the non-PO group (15.2° and 7.1 mm vs. 26.3° and 17.8 mm in the PO group; P = 0.000 and P = 0.000). The convex rods were less kyphotic in the non-PO group; for the non-PO group, the end angle and deflection were 27.6° and 16 mm versus 33.4° and 23.8 mm in the PO group (P = 0.03 and P = 0.000). No significant difference between the groups was observed for the convex rod apex angle (P = 0.8). The rod apices were more superimposed in the PO group (2.9 mm vs. 9.3 mm in the non-PO group; P = 0.000).

Conclusions

POs increase the overall sagittal kyphosis and improve the three-dimensional derotation of the apex in patients with AIS.

Management and surgical outcomes of dystrophic scoliosis in neurofibromatosis type 1: a systematic review

OBJECTIVE

Neurofibromatosis type 1 (NF1) dystrophic scoliosis is an early-onset, rapidly progressive multiplanar deformity. There are few studies on the surgical management of this patient population. Specifically, perioperative morbidity, instrument-related complications, and quality-of-life outcomes associated with surgical management have not been systematically evaluated. In this study, the authors aimed to perform a systematic review on the natural history, management options, and surgical outcomes in patients who underwent NF1 dystrophic scoliosis surgery.

METHODS

A PubMed search for articles with “neurofibromatosis” and either “dystrophic” or “scoliosis” in the title or abstract was performed. Articles with 10 or more patients undergoing surgery for NF1 dystrophic scoliosis were included. Data regarding indications, treatment details, morbidity, and outcomes were summarized and analyzed with descriptive statistics.

RESULTS

A total of 310 articles were identified, 48 of which were selected for full-text review; 30 studies describing 761 patients met the inclusion criteria. The mean age ranged from 7 to 22 years, and 99.7% of patients were younger than 18 years. The mean preoperative coronal Cobb angle was 75.2°, and the average correction achieved was 40.3°. The mean clinical follow-up in each study was at least 2 years (range 2.2–19 years). All patients underwent surgery with the intent of deformity correction. The scoliosis regions addressed were thoracic curves (69.6%) and thoracolumbar (11.1%) and lumbar (14.3%) regions. The authors reported on a variety of approaches: posterior-only, combined anterior-posterior, and growth-friendly surgery. For fixation techniques, 42.5% of patients were treated with hybrid constructs, 51.5% with pedicle screw–only constructs, and 6.0% with hook-based constructs. Only 0.9% of patients underwent a vertebral column resection. The nonneurological complication rate was 14.0%, primarily dural tears and wound infections. The immediate postoperative neurological deficit rate was 2.1%, and the permanent neurological deficit rate was 1.2%. Ultimately, 21.5% required revision surgery, most commonly for implant-related complications. Loss of correction in both the sagittal and coronal planes commonly occurred at follow-up. Five papers supplied validated patient-reported outcome measures, showing improvement in the mental health, self-image, and activity domains.

CONCLUSIONS

Data on the surgical outcomes of dystrophic scoliosis correction are heterogeneous and sparse. The perioperative complication rate appears to be high, although reported rates of neurological deficits appear to be lower than clinically observed and may be underreported. The incidence of implant-related failures requiring revision surgery is high. There is a great need for multicenter prospective studies of this complex type of deformity.

Ponte osteotomies increase risk of intraoperative neuromonitoring alerts in adolescent idiopathic scoliosis surgery

Background:

Ponte osteotomies (PO) are commonly used in adolescent idiopathic scoliosis (AIS) surgeries to improve the coronal and sagittal deformity correction. Here, we compared the incidence of perioperative neurologic complications for patients undergoing AIS with versus without PO.

Methods:

In a retrospective cohort study of 80 consecutive AIS patients undergoing scoliosis correction, 40 underwent PO, while 40 did not. All operations were performed by one surgeon at one tertiary care center. Patients’ demographics, Lenke classifications, surgical data, and deformity characteristics were comparable in both groups. Perioperative neurologic complications, defined as spinal cord or nerve root injuries identified by the surgeon, were tracked for those undergoing AIS surgery with or without PO being performed.

Results:

The risk of IOM alerts was significantly higher in the PO patients (12.5%: 5 patients) versus those in the No-PO group (0%, P = 0.021). Despite these changes, no patient incurred an increased postoperative deficit. Nevertheless, PO group patients demonstrated a higher coronal deformity correction rate (PO: 71% ± 10.9 vs. NoPO: 64.2% ± 11.5, P = 0.008) and a greater kyphosis Cobb angle (PO: 25.2 ± 6 vs. No-PO: 17.5 ± 9.4, P = 0.0001) on postoperative follow-up.

Conclusion:

While PO improved 3D correction of AIS, it increased the risk of IOM alerts in 12.5% of cases.

Evaluating flexibility and predicting curve correction using fulcrum-bending radiographs in Lenke type 2 adolescent idiopathic scoliosis

BACKGROUND

Fulcrum-bending (FB) correction is considered to provide the best estimation of main thoracic (MT) curve flexibility and postoperative correction in surgical treatment for adolescent idiopathic scoliosis (AIS). However, few studies evaluated the usefulness of FB radiographs for proximal thoracic (PT) curve. We aimed to perform flexibility assessments using both active side-bending (SB) and FB radiographs and evaluate surgical outcomes after posterior spinal fusion (PSF) for Lenke type 2 AIS.

METHODS

This study included 38 consecutive patients with Lenke type 2 AIS who underwent PSF using a pedicle screw construct with a minimum 2-year follow-up. Radiographic parameters, including correction rate, SB and FB flexibility, and FB correction index (FBCI: [correction rate/FB flexibility] × 100), were evaluated preoperatively, immediately after surgery, and at the 2-year follow-up. The clinical outcomes were preoperatively evaluated using the Scoliosis Research Outcomes Instrument-22 and at the follow-up.

RESULTS

All scoliosis curves significantly improved and shoulder balance shifted toward left shoulder elevation (all comparisons, p < 0.0001). There were significant differences between the SB and FB corrections in the PT and MT curves (p < 0.0001). The magnitudes of the discrepancies between the SB and FB corrections in the PT and MT curves were 11.2° ± 5.2° and 11.6° ± 7.2°, respectively. FB correction did not differ from postoperative Cobb angles correction immediately after surgery or at the 2-year follow-up; the mean FBCIs in the PT and MT curves were 98.8% and 105.5%, respectively. The self-image domain SRS-22 scores had significantly increased at the 2-year follow-up (p < 0.0001).

CONCLUSIONS

There were significant differences between the SB and FB corrections, and FB correction tended to approximate the postoperative curve correction (FBCI = 100%) for PT and MT curves in patients with Lenke type 2 AIS. FB flexibility is more reliable than SB flexibility in evaluating actual curve flexibility even for the PT curve.

Posterior spine fusion in a Jehovah's Witness patient with severe rigid idiopathic scoliosis – A case report

Introduction

Early onset scoliosis (EOS) represent a challenge for spine surgeons. The selection of the best treatment is complex. Some patients, such as Jehovah's Witnesses who refuse blood transfusions, are at high risk of complication when surgical treatment is required because blood loss is a major cause of morbidity and postoperative transfusion rates.

Research question

Describe blood-saving techniques that allowed an extensive and invasive surgical procedure in a Jehovah's Witness patient.

Material and method

17-year-old Jehovah's Witness girl with severe 120° Cobb Lenke 1A idiopathic scoliosis started as EOS was prepared with 4 cycles of recombinant human erythropoietin, iron and folic acid supplementation that brought her hemoglobin level from 13.6 g/dl to 16.2 g/dl. In the first surgical time, a temporary rod was implanted. Spine dissection using bipolar sealer and a special electrocautery that operates at lower temperatures than traditional ones was performed. Facetectomies and multilevel Ponte osteotomies was performed using an ultrasonic bone scalpel. The second surgical time, the definitive rods were placed, and the correction of the deformity was achieved using the rod link reducer technique.

Results

A good correction of the main curve in the coronal plane is achieve. The Hb nadir was 7.2 g/dl four days after the second operation. The postoperative course was uneventful.

Discussion and conclusion

The integration of modern and traditional preoperative, intraoperative, and postoperative blood sparing techniques allowed us to perform an extensive and invasive surgical procedure in a Jehovah's Witness girl with a severe idiopathic scoliosis.

•

The management of spine deformities in JW patients represent a challenges for spine surgeons.

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In pediatric scoliosis fusion surgery, blood loss is a major cause of morbidity.

•

Preoperative, intraoperative, postoperative blood sparing techniques are essential for a good result.

Ponte osteotomies in a matched series of large AIS curves increase surgical risk without improving outcomes

PURPOSE

The routine use of Ponte osteotomies in adolescent idiopathic scoliosis (AIS) surgery is controversial with conflicting data for coronal plane correction and little analysis in the sagittal plane. The objective of this study was to analyze the efficacy of Ponte osteotomies in large curve AIS.

METHODS

A single institution, prospectively-collected series of consecutive AIS patients who had Ponte osteotomies (P cohort) was directly matched to patients with no Pontes (NP cohort) by age, gender, Lenke classification, surgeon, coronal, and sagittal Cobb angles. The radiographic review included adjusted values using a 3D-derived published formula for preoperative T5-T12 kyphosis. Patient-reported outcomes (PROs) were assessed with the SRS-30 and Spinal Appearance Questionnaire (SAQ).

RESULTS

There were 68 patients (34/cohort) with minimum 2-year follow-up with no differences between P and NP cohorts in age, preoperative coronal Cobb (74.5° vs 70.8°), flexibility index, measured or 3D-adjusted T5-T12 kyphosis. Rod material/diameter, fusion levels, blood loss, and operative time did not differ, but implant density was higher in the P group (1.53 vs 1.31, p < 0.001). The P group had 7.9% greater coronal Cobb correction (66.6% vs 58.7%, p < 0.003) without difference in final Cobb angles (24.7° vs. 29.1°, p = 0.052). There were no differences in measured or adjusted T5-T12 kyphosis in the sagittal plane. The P group had a 15% rate of critical intraoperative neuromonitoring changes versus 0% in the NP group (p = 0.053). At follow-up, there were no differences in scoliometer measurements or any domain of SRS-30 or SAQ scores.

CONCLUSION

In this first reported matched series of AIS patients, Ponte osteotomies provide small radiographic gains in the coronal plane with no improvement in the sagittal plane and no change in truncal rotation. There was a higher risk of critical intraoperative neuromonitoring changes, and no benefits in patient-reported outcomes. This calls into question the routine use of Ponte osteotomies in AIS, even for curves averaging 70 degrees.

LEVEL OF EVIDENCE

II.

Short term outcomes of an enhanced recovery after surgery (ERAS) pathway versus a traditional discharge pathway after posterior spinal fusion for adolescent idiopathic scoliosis

PURPOSE

Enhanced Recovery after Surgery (ERAS) pathways have been shown to decrease length of stay (LOS) after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). The aim of this study was to compare immediate post-operative outcomes following an ERAS pathway with a traditional pathway for AIS.

METHODS

A prospective dual-center study of patients treated using an ERAS pathway (203 patients) or a traditional discharge (TD) pathway (73 patients) was performed with focus on pain at discharge, quality of life at one month, and return to school/work.

RESULTS

LOS was 55% less in the ERAS group (4.8 days TD vs. 2.2 days ERAS, p < 0.001). Length of surgery (4.8 h TD vs. 2.8 h, p < 0.001) and EBL (500 cc vs. 240 cc, p < 0.001) were greater in the TD group, likely related to larger curve magnitudes ((62.0° TD vs. 54.0° ERAS, p < 0.001), a higher percentage of patients undergoing osteotomies (94% vs. 46%, p < 0.001) and more levels fused (11.4 ± 1.6 vs. 10.1 ± 2.6, p < 0.001) in the TD group. Regression analysis showed no difference in Visual Analog Score (VAS) score at discharge or quality of recovery using the QOR9 instrument between groups at follow up. There was no difference in return to school (p = 0.43) and parents' return to work (p = 0.61) between the groups.

CONCLUSION

Patients managed with an ERAS pathway had similar pain scores at discharge than those managed with a TD pathway. Both groups showed evidence of rapid return to normalcy by the first follow up visit.

Hi-PoAD technique for Adolescent Idiopathic Scoliosis in Adult: Personal case series

PURPOSE

The aim of this article is to present an original surgical technique for the treatment of rigid Adult Idiopathic Scoliosis (AdIS) and the results at minimum 2 years follow-up in a cohort of 40 patients.

METHODS

We retrospectively reviewed 40 patients affected by rigid AdIS, older than 40 years and operated with a posterior one stage surgical technique summarized with the acronym Hi-PoAD, (high-density pedicle screws, Ponte osteotomies, asymmetric rods contouring, direct vertebral rotation). The demographic and surgical data were collected, and the improvement of clinical scores and radiologic parameters was obtained after surgery, at 1 and 2 years and at final follow-up, to assess deformity correction, coronal and sagittal balance and clinical outcome.

RESULTS

The average follow-up was 2.9 years (range 2-3.5). Average coronal Cobb angle decreased from 65.0° ± 8.4 to 18.9° ± 3.9 (p < 0.01). Rotation sagittal angle decreased from 26.2° ± 4.4° to 12.4° ± 2.8° (p < 0.01). Mean thoracic kyphosis improved from 23.1° ± 3.6° to 36.0° ± 3.9°. SRS-22 improved form 2.9 ± 0.4 to 3.7 ± 0.6 (p < 0.01). Four early post-operative deep wound infections were observed, all healed after debridement and implant retention. No mechanical complication, junctional kyphosis, deformity progression or non-union were recorded at the last follow-up.

CONCLUSIONS

Hi-PoAD technique proved to be safe and effective in the treatment of rigid Adult Idiopathic Scoliosis. The reason for the success is related to the combined strategies adopted, that dissipates corrective forces over several levels, reducing mechanical stress at the screw-bone interface and optimizing corrective potential.

Impact of multilevel facetectomy on segmental spinal flexibility in patients with thoracic adolescent idiopathic scoliosis

BACKGROUND

The aim of this study was to intraoperatively assess the effects of multilevel facetectomy on segmental spinal flexibility in patients with thoracic adolescent idiopathic scoliosis.

METHODS

Twenty patients who underwent posterior thoracic adolescent idiopathic scoliosis curve correction were evaluated. Compressive or distractive loaded force of 50N was applied on the handle of a compressor or distractor connected to the necks of pedicle screws inserted at T7 to T11. Segmental spinal flexibility rates were calculated based on the distance between screw heads under the loaded and unloaded conditions. In addition, the flexibility rates were obtained before and after multilevel facetectomy.

FINDINGS

Absolute flexibility rates of all segments significantly increased after multilevel facetectomy under both compressive and distractive forces (P < 0.01). The absolute change in the flexibility rate was significantly higher at the concave side than at the convex side under both compressive (P < 0.01) and distractive loaded forces (P = 0.046). No significant correlation was found between change in the flexibility rates and preoperative Cobb angle or preoperative curve flexibility.

INTERPRETATION

From a biomechanical point of view, multilevel facetectomy provides proper spinal flexibility to improve the correction rate of posterior adolescent idiopathic scoliosis surgery. The effects are higher at the concave side than at the convex side.

Clinical and Radiological Outcomes of Less Invasive Temporary Internal Distraction Followed by Staged Pedicle Screw Instrumentation in Adolescents with Severe Idiopathic Scoliosis at 2-Year Minimum Follow-Up

OBJECTIVES

Temporary placement of an internal distraction rod is one of the surgical options in the treatment of severe scoliosis to avoid preoperative halo traction or vertebral column resection. This technique can be applied in a single session or staged. The aim of our study was to report the outcomes of less-invasive temporary internal distraction (LI-TID) in the surgical treatment of adolescents with severe idiopathic scoliosis (IS).

METHODS

We performed a single-center, retrospective study of 22 adolescents (19 girls; mean age, 14.8 ± 2.0 years) with severe IS (major curve, ≥90°) who had undergone LI-TID, followed by staged pedicle screw instrumentation, with a minimum of 2 years of follow-up available. The demographic data, radiographic outcomes, pulmonary function test results, perioperative data, revised 22-item Scoliosis Research Society Outcomes questionnaire results, complications, and neuromonitoring data were collected.

RESULTS

The average major curve was 120° (range, 90°-160°) preoperatively and 59° (range, 29°-69°) at the final follow-up examination. Thoracic kyphosis (T5-T12) had improved from an average of 80° preoperatively to 33° postoperatively (range, 22°-69°), and the spinal height (T1-S1) had increased from 332 mm (range, 198-432 mm) preoperatively to 405 mm (range, 258-495 mm) at the final follow-up visit. Of the 22 patients, 5 (22.7%) had experienced an intraoperative neuromonitoring change without postoperative neurologic deficits, and 2 had developed superior mesenteric artery syndrome, with resolution after conservative treatment. The mean percentage of the predicted forced vital capacity had improved from 44.5% ± 11.3% to 66.5 ± 10.8 at final follow-up (P < 0.05). The total questionnaire score had improved significantly from 2.9 ± 0.61 to 4.1 ± 0.44 (P < 0.05).

CONCLUSION

The results from the present study have shown that staged LI-TID, followed by pedicle screw instrumentation, is safe and effective in adolescents with severe IS, with improvements in spinal deformity, pulmonary function, and health-related quality of life.

Posterior Correction Techniques for Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis represents a complex, three-dimensional deformity of the spine. Posterior spinal fusion is commonly performed in severe cases to avoid the long-term adverse sequelae associated with progressive spinal deformity. The goals of spinal fusion include halting the progression of deformity, optimizing spinal balance, and minimizing complications. Recent advances in short-segment spinal fixation have allowed for improved three-dimensional deformity correction. Preoperative planning and assessment of spinal flexibility is essential for successful deformity correction and optimization of long-term outcomes. Judicious use of releases and/or spinal osteotomies may allow for increased mobility of the spine but are associated with increased surgical time, blood loss, and risk of complications. Appreciation of implant design and material properties is critical for safe application of correction techniques. Although multiple reduction techniques have been described, no single technique is optimal for every patient.

Are inferior facetectomies adequate and suitable for surgical treatment of adolescent idiopathic scoliosis?

STUDY DESIGN

Retrospective review.

BACKGROUND

Inferior facetectomies, with the utilization of segmental pedicle screw constructs for corrective fixation, can provide adequate flexibility and post less risk of neural tissue and blood loss. We analyzed outcomes of surgical treatment for adolescent idiopathic scoliosis (AIS) using inferior facetectomies and segmental pedicle screw constructs. We hypothesized that adequate main curve correction and suitable surgical outcomes would be observed using this technique.

METHODS

We reviewed 38 AIS patients who underwent inferior facetectomies and segmental pedicle screw constructs by 2 surgeons at a single institution between May 2014 and December 2016. Coronal and sagittal radiographic measurements were evaluated over 1-year follow-up by 2 trained observers not associated with the surgeries. Surgical details, complications, and hospital length of stay (LOS) were also recorded.

RESULTS

Mean fusion levels were 11.0 ± 1.7. The mean Cobb angle of main AIS curves improved from 48.6± 10.1 degree preoperatively to 11.8± 6.2 degree postoperatively and 12.4± 6.2 degree at 1-year follow-up, which percentage correction was 75.9% and 74.6%, respectively. The mean thoracic kyphosis (T5-12) angle was 20.7± 11.6 degree preoperatively, 17.4± 8.0 degree postoperatively, and 16.8± 8.4 degree at 1-year follow-up. The mean surgical time, estimated blood loss, and LOS were 232.4 ± 35.7 minutes, 475.0 ± 169.6 mL, and 3.5 ± 1.3 days. Twelve patients received blood transfusion. There were no neurological or wound complications.

CONCLUSIONS

This case series demonstrated adequate correction of main AIS curves, acceptable thoracic kyphosis and blood loss, and short surgical time and LOS in AIS patients treated with inferior facetectomies and segmental pedicle screw constructs, potentially indicating that inferior facetectomies are adequate and suitable for AIS surgery when segmental pedicle screw constructs are utilized.

One-Stage Posterior Multiple-Level Asymmetrical Ponte Osteotomies Versus Single-Level Posterior Vertebral Column Resection for Severe and Rigid Adult Idiopathic Scoliosis: A Minimum 2-Year Follow-up Comparative Study

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

To compare the efficacy and safety of one-stage posterior multiple-level asymmetrical Ponte osteotomies (MAPOs) and single-level posterior vertebral column resection (VCR) for severe and rigid adult idiopathic scoliosis (ADIS).

SUMMARY OF BACKGROUND DATA

The surgical treatment of severe and rigid ADIS is a demanding and difficult challenge due to its complicated characteristics. Spine surgeons have often pursued advanced correction techniques such as VCR for such patients, which reported to present excellent correction outcomes. But this attractive procedure brought the greatest risk to both surgeons and patients.

METHODS

A total of 48 patients who underwent MAPO or VCR and fusion surgery with minimum 2-year follow-up between February 2009 and November 2015 were enrolled. Twenty-six patients were included in MAPO group and 12 patients in VCR group with an average age of 26.65 ± 8.40 and 27.92 ± 7.50 years, respectively. The average follow-up was 30.24 ± 10.55 months. The surgical details and complications were recorded. The radiological parameters and clinical outcome including Oswestry Disability Index and Scoliosis Research Society-22 questionnaire scores were collected and analyzed.

RESULTS

The main curve in MAPO and VCR group were corrected from an average of 98.52° ± 16.50° to 44.11° ± 17.72° and 108.91° ± 16.56° to 56.49° ± 18.82° with no significant difference. The postoperative coronal and sagittal parameters of the two groups were all improved and it showed no significant differences between the two groups. The mean operative time and blood loss of VCR group were significantly greater than those of MAPO group. All the clinical scores were significantly improved at final follow-up, with no significant difference. The incidence of complications in MAPO group was 3.85%, which was significantly lower than that of VCR group.

CONCLUSION

The surgical procedure of multiple asymmetrical Ponte osteotomy is a safe, easy-to-operate, and effective technique that can correct scoliosis and restore the sagittal alignment. It can gain similar correction outcome to VCR, offering the advantages of reduced operation time, blood loss, and greatly reduced the complication.

LEVEL OF EVIDENCE

3.

Posterior Multiple-Level Asymmetrical Ponte Osteotomies for Rigid Adult Idiopathic Scoliosis

OBJECTIVE

To evaluate the efficacy and safety of posterior multiple-level asymmetrical Ponte osteotomies for rigid adult idiopathic scoliosis.

METHODS

A retrospective study was conducted for adult patients with rigid idiopathic scoliosis (flexibility of main curve <25%) who underwent one-stage multiple-level asymmetrical Ponte osteotomies with a minimum of 2-year follow-up between February 2009 and November 2015. The demographic data and surgical issues were collected, and the improvement of clinical function scores and radiologic parameters were obtained after surgery and during the follow-up to assess deformity correction, spinal balance, and clinical outcome.

RESULTS

A total of 49 patients were included (10 male and 39 female) in this study, with an average age of 26.53 years old. The average follow-up was 28.37 ± 6.98 months. All the cases presented a significant improvement of the main curve and focal kyphosis from 85.62 ± 19.80° to 36.19 ± 16.74° and 53.98 ± 26.80° to 30.88 ± 18.69°, with a mean correction rate of 57.73% and 41.23%. The postoperative coronal and sagittal parameters were all significantly improved, except coronal balance. The mean operative time and blood loss were 267.86 ± 54.49 minutes and 838.78 ± 538.93 mL. All the clinical function scores of patients were significantly improved at the final follow-up. Only one patient had a complication related to surgical incision, with no neurologic complications occurring.

CONCLUSIONS

The surgical procedure of multiple-level asymmetrical Ponte osteotomy is a safe and effective technique, with reduced operation time, blood loss, and complications, and may offer an appropriate option to address the problems of rigid adult idiopathic scoliosis.

Ponte Osteotomies Increase the Risk of Neuromonitoring Alerts in Adolescent Idiopathic Scoliosis Correction Surgery

STUDY DESIGN

Observational cohort study of prospective database registry.

OBJECTIVE

To determine the incidence of neurological complications in AIS patients undergoing surgical treatment with PO.

SUMMARY OF BACKGROUND DATA

Despite the widespread use of Ponte Osteotomies (PO) in adolescent idiopathic scoliosis (AIS) correction, outcomes and complications in patients treated with this technique have not been well characterized.

METHODS

A multicenter prospective registry of patients undergoing surgical correction of AIS was queried at 2-year follow-up for patient demographics, surgical data, deformity characteristics, and peri-operative complications. A neurological complication was defined as perioperative nerve root or spinal cord injury as identified by the surgeon. Patients were divided into those who underwent peri-apical PO and those without, and further stratified by Lenke curve classification into 3 groups (I-types 1 and 2, II-types 3, 4, 6, and III-type 5). Patients with- and without neurological complications were compared with respect to baseline demographics, surgical variables, curve types, fusion construct types (screws vs. hybrid), curve magnitude (coronal and sagittal Cobb), apical vertebral translation, and coronal-deformity angular ratios (C-DAR).

RESULTS

Of 2210 patients included in the study, 1611 underwent PO. Peri-operative neurological complications occurred in 7 patients, with 6 in the PO group (0.37%) and 1 in non-PO group (0.17%) though this was not a statistically significant risk factor for peri-operative neurological injury (P = 0.45). Neuromonitoring alerts were recorded in 168 patients (7.6%: 9.3% PO group; 4.2% no-PO group (P < 0.001)). Multivariate logistic regression analysis found PO and curve magnitude to be independent risk factors for intraoperative neuromonitoring alerts (P < 0.01).

CONCLUSION

PO and curve magnitude were independent risk factors for intraoperative neuromonitoring alerts in surgical AIS correction. The effect of Ponte osteotomy on neurological complications remains unknown due to the low incidence of these complications.

LEVEL OF EVIDENCE

3.

Clinical and radiological outcomes of the multilevel Ponte osteotomy with posterior selective segmental pedicle screw constructs to treat adolescent thoracic idiopathic scoliosis

Background

To compare the clinical and radiological outcomes of the surgical correction of Lenke type 1 to 4 scoliosis by using a multilevel Ponte osteotomy procedure with posterior selective segmental pedicle screw constructs or posterior release and selective segmental pedicle screw constructs only in patients with adolescent thoracic idiopathic scoliosis.

Methods

Retrospective analysis of 65 patients, 32 treated with the multilevel Ponte procedure (Group A) and 33 with posterior soft tissue release only (Group B). The groups were compared with regard to the change in spinal alignment from preoperative to postoperative assessment and over the follow-up period.

Results

A correction rate of the main thoracic curve of 63.9 ± 4.5% was obtained for group A and 65.2 ± 2.4% for group B (P = 0.17). However, the Cincinnati correction index was greater for group A (1.8 ± 0.3) than that for group B (1.4 ± 0.2, P < 0.001), with a smaller change in angle over the period from 1 week postoperatively to the 2-year follow-up (P < 0.05). The operative time, volume of blood loss, and volume of transfusion were greater for group A than for group B (P < 0.05).

Conclusion

The multilevel Ponte osteotomy procedure, with posterior selective segmental pedicle screw constructs, improves the Cincinnati correction index and restores the thoracic kyphosis in patients with adolescent thoracic idiopathic scoliosis.

The True Ponte Osteotomy: By the One Who Developed It

STUDY DESIGN

Technique and applications.

OBJECTIVES

To define the anatomy, biomechanics, indications, and surgical technique of the true Ponte osteotomy.

SUMMARY OF BACKGROUND DATA

The Ponte osteotomy, originally developed for thoracic kyphosis, was the first one to obtain posterior shortening of the thoracic spine, maintaining the anterior column load-sharing capacity. It has become a widely applied technique in various types of spine deformities and a frequent topic of presentations at meetings and in scientific articles. Several of them offer unquestionable evidence of an incorrect execution, with consequently distorted outcomes and erroneous conclusions. A clearing up became essential.

METHODS

Our original experience is based on a series of 240 patients with thoracic hyperkyphosis operated in the years 1969-2015, at first with a standard posterior Harrington technique and then by using the Ponte osteotomy with different instrumentations. A series of 78 of them, operated in the years 1987-1997, who had Ponte osteotomies at every level, is presented.

RESULTS

The average preoperative kyphosis has been corrected from 80° (range 61°-102°) to 31° (range 15°-50°) by a substantial posterior shortening.

CONCLUSIONS

A number of publications use the term Ponte osteotomy loosely for by far incomplete resections and mixing it up with Smith-Petersen's osteotomy. The true Ponte osteotomy is capable of producing marked flexibility in extension, flexion and rotation, justifying its wide use in thoracic deformities, mainly in scoliosis. An exact performance of the osteotomy with adequate bony resections, including the laminae, is an absolute condition to take full advantage of its properties.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Multilevel Posterior Column Osteotomies Are Not Inferior For the Correction of Rigid Adult Spinal Deformity Compared with Pedicle Subtraction Osteotomy

BACKGROUND

Posterior column osteotomy (PCO) has been used for the correction of various spinal deformities. However, little evidence is available regarding the effects of multilevel PCO in adult spinal deformity (ASD) surgery. This study aimed to show the usefulness of PCO in rigid ASD surgery by assessing radiographic and clinical outcomes. We also aimed to assess the corrective potential of multilevel PCOs compared with a single-level pedicle subtraction osteotomy (PSO).

METHODS

Between 2012 and 2016, the medical records of 70 consecutive patients who underwent a multilevel PCO (35 patients) or a single-level PSO (35 patients) for ASD in a single institute were reviewed. Baseline data, radiographic measurements, and clinical outcomes using the Scoliosis Research Society-22 (SRS-22) questionnaire were compared between groups.

RESULTS

The following variables were no different between the groups: age at surgery, sex, level fused, preoperative and postoperative radiologic parameters, and bone mineral density T score. However, operation time (380.0 vs. 483.6 minutes), estimated blood loss (1175.7 vs. 1362.6 mL), and the number of complications (8 vs. 20) were significantly reduced in the PCO group compared with the PSO group. A significant improvement in the SRS-22 score was seen in both groups after surgery, although no difference was observed between the groups postoperatively.

CONCLUSIONS

Multilevel PCOs for the correction of rigid ASD were slightly superior to PSO, regarding clinical outcomes. Radiographic outcomes were similar between groups. Thus, multilevel PCOs may be a viable option for the treatment of rigid ASD with a mobile segment.