Is there a skeletal age index that can predict accurate curve progression in adolescent idiopathic scoliosis? A systematic review.

BACKGROUND: The diagnosis of adolescent idiopathic scoliosis requires clinical and radiographic evaluation; the management options vary depending on the severity of the curve and potential for progression. Identifying predictors of scoliosis progression is crucial to avoid incorrect management; clinical and radiographic factors have been studied as potential predictors. The present study aims to review the literature on radiological indexes for the peak height velocity or curve acceleration phase to help clinicians manage treatment of patients with adolescent idiopathic scoliosis. METHODS: This systematic review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The search was carried out including only peer-reviewed articles written in English that described the radiological indexes assessing skeletal maturity in patients with adolescent idiopathic scoliosis and evaluated their correlation with curve progression, expressed as peak height velocity and/or curve acceleartion phase. RESULTS: Thirteen studies were included and showed promising results in terms of reliable radiological indexes. Risser staging gives a general measure of skeletal maturity, but it cannot be used as a primary index for driving the treatment of patients with adolescent idiopathic scoliosis since more reliable indexes are available. CONCLUSION: Skeletal maturity quantification for adolescent idiopathic scoliosis has the potential to significantly modify disease management. However, idiopathic scoliosis is a complex and multifactorial disease: therefore, it is unlikely that a single index will ever be sufficient to predict its evolution. Therefore, as more adolescent idiopathic scoliosis progression-associated indexes are identified, a collective scientific effort should be made to develop a therapeutic strategy based on reliable and reproducible algorithms.

A reduction in tumor volume exceeding 65% predicts a good histological response to neoadjuvant chemotherapy in patients with Ewing sarcoma.

OBJECTIVE: No consensus exists for tumor volume response criteria in patients with Ewing sarcoma. This study aimed to identify an optimal cutoff for predicting a good histological response by analyzing tumor volume changes and tumor necrosis after neoadjuvant chemotherapy. MATERIALS AND METHODS: We performed a retrospective analysis of 184 Ewing sarcoma patients, analyzing tumor volume changes before and after neoadjuvant chemotherapy. Patients were divided into two groups based on histological response: good (tumor necrosis ≥ 95%) and poor (tumor necrosis < 95%) responders. The receiver operating characteristic (ROC) area under the curve (AUC) method was used to determine the optimal thresholds for predicting the histological response. Additionally, the prognostic value of this cutoff for relapse-free survival was assessed. RESULTS: Out of 184 patients, 83 (45%) had tumor necrosis ≥ 95%, while 101 (55%) had tumor necrosis < 95%. ROC analysis identified the optimal cutoff for a good histological response as over 65% tumor volume reduction (AUC = 0.69; p < 0.001). Patients with volume reduction of ≥ 65% had a higher likelihood of a good histological response than those with lesser reductions (p = 0.004; odds ratio = 2.61). Multivariable analysis indicated a correlation between poor histological response and reduced relapse-free survival (hazard ratio = 2.17; p = 0.01), while tumor volume reduction itself did not impact survival. CONCLUSION: We reported that a tumor volume reduction of ≥ 65% was able to predict a good histological response in Ewing sarcoma patients. We recommend preoperative tumor volume assessment to identify patients at greater risk for poor histological response who could benefit from more intensive chemotherapy protocols or additional radiotherapy.

A Pilot Study on Circulating, Cellular, and Tissue Biomarkers in Osteosarcopenic Patients.

Aging comes with the loss of muscle and bone mass, leading to a condition known as osteosarcopenia. Circulating, cellular, and tissue biomarkers research for osteosarcopenia is relatively scarce and, currently, no established biomarkers exist. Here we find that osteosarcopenic patients exhibited elevated basophils and TNFα levels, along with decreased aPPT, PT/INR, IL15, alpha-Klotho, DHEA-S, and FGF-2 expression and distinctive bone and muscle tissue micro-architecture and biomarker expressions. They also displayed an increase in osteoclast precursors with a concomitant imbalance towards spontaneous osteoclastogenesis. Similarities were noted with osteopenic and sarcopenic patients, including a lower neutrophil percentage and altered cytokine expression. A linear discriminant analysis (LDA) on models based on selected biomarkers showed a classification accuracy in the range of 61-78%. Collectively, our data provide compelling evidence for novel biomarkers for osteosarcopenia that may hold potential as diagnostic tools to promote healthy aging.

Identification of Epigenetic Biomarkers of Adolescent Idiopathic Scoliosis Progression: A Workflow to Assess Local Gene Expression.

Adolescent idiopathic scoliosis (AIS) is a three-dimensional structural deformity of the spine that affects 2-3% of adolescents under the age of 16. AIS etiopathogenesis is not completely understood; however, the disease phenotype is correlated to multiple genetic loci and results from genetic-environmental interactions. One of the primary, still unresolved issues is the implementation of reliable diagnostic and prognostic markers. For clinical management improvement, predictors of curve progression are particularly needed. Recently, an epigenetic contribution to AIS development and progression was proposed; nevertheless, validation of data obtained in peripheral tissues and identification of the specific mechanisms and genes under epigenetic control remain limited. In this study, we propose a methodological approach for the identification of epigenetic markers of AIS progression through an original workflow based on the preliminary characterization of local expression of candidate genes in tissues directly involved in the pathology. The feasibility of the proposed methodological protocol has been originally tested here in terms of identification of the putative epigenetic markers of AIS progression, collection of the different tissues, retrieval of an appropriate amount and quality of RNA and DNA, and identification of suitable reference genes.

Giant cell tumor of bone with secondary aneurysmal bone cyst does not have a higher risk of local recurrence.

BACKGROUND: Fluid-fluid levels (FFLs) is found in 10%-16% of giant cell tumor of bone (GCTB), and the presence of FFLs raises the suspicion of GCTB with secondary aneurysmal bone cyst (ABC), which can lead to increased intraoperative bleeding and, blurring the operative field, be associated with a risk of local recurrence. The first objective of this study is to determine whether secondary ABC is associated with a higher risk of local recurrence after curettage in patients with GCTB of the extremities. The second objective of this study is to investigate the sensitivity, specificity, positive predictive value, and negative predictive value of the presence of FFLs detected on magnetic resonance imaging (MRI) to diagnose secondary ABC associated with GCTB. METHODS: Two hundred and eighty patients with GCTB of the extremities who underwent curettage at the authors' institutions between 1980 and 2021 were included in this study. RESULTS: Secondary ABC was found in 36 of 280 patients (12.9%) and local recurrence occurred in 66 of 280 patients (23.6%). Multivariate analysis showed no significant correlation between secondary ABC and local recurrence (hazard ratio [HR]: 1.87 (95% confidence interval [CI]: 1.00-3.53]; p = 0.051). Preoperative MRI revealed FFLs in 13 of 82 patients (15.9%). Sensitivity, specificity, positive predictive value, and negative predictive value of FFLs detected on preoperative MRI to diagnose secondary ABC were 36.8%, 90.5%, 53.8%, and 82.6%, respectively. CONCLUSION: The results of this study showed that secondary ABC does not increase the risk of local recurrence after curettage in patients with GCTB of the extremities. Although rare, FFLs were present in patients with GCTB and half of those with FFLs detected on preoperative MRI had secondary ABC.

Mechanobiology of the Human Intervertebral Disc: Systematic Review of the Literature and Future Perspectives.

Low back pain is an extremely common condition with severe consequences. Among its potential specific causes, degenerative disc disease (DDD) is one of the most frequently observed. Mechanobiology is an emerging science studying the interplay between mechanical stimuli and the biological behavior of cells and tissues. The aim of the presented study is to review, with a systematic approach, the existing literature regarding the mechanobiology of the human intervertebral disc (IVD), define the main pathways involved in DDD and identify novel potential therapeutic targets. The review was carried out in accordance with the Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies were included if they described biological responses of human IVD cells under mechanical stimulation or alterations of mechanical properties of the IVD determined by different gene expression. Fifteen studies were included and showed promising results confirming the mechanobiology of the human IVD as a key element in DDD. The technical advances of the last decade have allowed us to increase our understanding of this topic, enabling us to identify possible therapeutic targets to treat and to prevent DDD. Further research and technological innovations will shed light on the interactions between the mechanics and biology of the human IVD.

Epigenetic Factors Related to Low Back Pain: A Systematic Review of the Current Literature.

Low back pain (LBP) is one of the most common causes of pain and disability. At present, treatment and interventions for acute and chronic low back pain often fail to provide sufficient levels of pain relief, and full functional restoration can be challenging. Considering the significant socio-economic burden and risk-to-benefit ratio of medical and surgical intervention in low back pain patients, the identification of reliable biomarkers such as epigenetic factors associated with low back pain could be useful in clinical practice. The aim of this study was to review the available literature regarding the epigenetic factors associated with low back pain. This review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was carried out in October 2022. Only peer-reviewed articles were considered for inclusion. Fourteen studies were included and showed promising results in terms of reliable markers. Epigenetic markers for LBP have the potential to significantly modify disease management. Most recent evidence suggests that epigenetics is a more promising field for the identification of factors associated with LBP, offering a rationale for further investigation in this field with the long-term goal of finding epigenetic biomarkers that could constitute biological targets for disease management and treatment.

Accuracy of Patient-Specific 3D-Printed Guides for Pedicle Screw Insertion in Spine Revision Surgery: Results of a Retrospective Study.

PURPOSE: This retrospective study was performed to evaluate the safety and efficacy of patient-specific 3D-printed guides (MySpine® Medacta, Switzerland) for pedicle screw placement in spine revision surgery. Overview of the Literature: Placement of pedicle screws in spine revision surgery can be challenging due to the loss of anatomical landmarks and the presence of a fusion mass. Nevertheless, only a few papers have dealt with this topic. Several strategies, ranging from the freehand technique to navigation and robotics, have been developed. However, they all have drawbacks, including the amount of radiation given to the patient, the complexity of the equipment with a consequent increase in surgical time or costs, and the need of extended surgical training. Therefore, no consensus has yet been found regarding the best choice for dealing with revisions. Recently, patient-specific 3D-printed guides for screw placement have been introduced. Prospective studies have demonstrated their superiority over the freehand technique in primary deformity cases, but there are no studies on their results in revisions. METHODS: Patients who underwent revision surgery for adult spinal deformities with 3D-printed guides were included. Radiographical parameters and complications were collected. The accuracy of each screw was measured on postoperative CT scan and graded according to the Gertzbein-Robbins and Zdichavsky classifications. RESULTS: Nine patients (mean age 34.6 years, mean follow-up 34.4 months) were included for a total of 203 screws. The relative accuracy (Gertzbein-Robbins A+B) was 94.7%. Of the 11 misplaced screws, 8 (72.7%) were lateral, 3 (27.3%) were anterior and 0 were medial. No perioperative complications were recorded, and no screw needed revision. CONCLUSIONS: The present technology appears to be effective and safe for pedicle screw placement in spine revision surgery and does not require the costs, training and radiation exposure associated with navigation and robotics.

Pedicle Dysplasia in Proximal Thoracic Adolescent Idiopathic Scoliosis Curves: What are We Missing and What are its Possible Surgical Implications? An Observational Retrospective Study on 104 Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To assess if pedicle dysplasia is present in proximal thoracic (PT), both structural and nonstructural, compared to main thoracic (MT) curves; and to assess if it is predictive of radiographic outcomes at minimum 2 years of follow-up. METHODS: A retrospective review of surgically-treated Adolescent Idiopathic Scoliosis (AIS) patients with Lenke 1-2-3-4 curves was performed. On preoperative CT-scan, at the apical vertebra, pedicle width on the concavity (PWc) and on the convexity (PWv) and Pedicle Dysplasia Index (PDI, defined as PWc/PWv) were measured. Preoperative and last follow-up (at least 2 years) x-rays were reviewed. RESULTS: 104 patients meeting the inclusion criteria were divided into Structural-PT (S-PT) and Nonstructural-PT (NS-PT) groups based on Lenke criteria. PWc (P < .001). And PDI (P < .001 for S-PT, P = .004 for NS-PT) were significantly smaller in the PT than in MT curves for both groups. PT-PWc significantly correlated with follow-up PT Cobb for both groups (P < .001 and P = .015 respectively). PT-PDI significantly correlated with follow-up PT-Cobb (P < .001), CA (P < .040) and T1 tilt (P < .002), only for NS-PT group. NS-PT patients with PWc PT <1 mm had higher RSHD (P = .021) and T1 tilt (P = .025) at follow-up. NS-PT patients with PDI PT <.3 had higher RSHD (P < .001), CA (P = .002) and T1 tilt (P = .003) at follow-up. CONCLUSION: S-PT and NS-PT curves show significant pedicle dysplasia on the concavity. Pedicle dysplasia significantly correlated with shoulder balance at follow-up, for NS-PT patterns. Patients with a PWc <1 mm or PDI <.30 are at particular risk of postoperative shoulder imbalance.

Comparison Between Resident and Attending Surgeons as Assistants on Adolescent Idiopathic Scoliosis Surgery: No Differences in Outcomes, Complications Rate, or Pedicle Screw Placement Accuracy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of the present study was to determine if the level of training of the first assistant (resident or attending surgeon) has an influence on the radiographic outcome of AIS surgery and on the accuracy rate of the pedicle screws placement. SUMMARY OF BACKGROUND DATA: Adolescent idiopathic scoliosis (AIS) surgery is a challenging procedure that requires a dedicated team of skilled professionals. Therefore, understanding the learning curve is of outstanding importance to guarantee the best outcomes and the highest safety to the patients. METHODS: A retrospective analysis of patients who underwent surgery for AIS with a minimum follow-up of 2 years was conducted. All patients were operated by an experienced spine surgeon, assisted by and attending surgeon (group A) or a senior resident (group B). Radiographic outcomes were assessed. Through postoperative CT scan, accuracy of pedicle screw placement was measured (using Gertzbein-Robbins classification). Groups were then statistically compared. RESULTS: A total of 120 patients were included (mean age 15.3±3.39 y, major curve Cobb 60.7±11.9 degrees). No difference was found between groups in terms of preoperative characteristics and postoperative radiographic (correction rate, thoracic kyphosis, screw density) outcomes or complications. Operative time and estimated blood loss were significantly higher in Group B (P=0.045 and P=0.024, respectively). Of the 2746 pedicle screws inserted (1319 group A and 1427 group B), 2452 had a perfect intrapedicular trajectory (absolute accuracy of 89.29%) and 2697 had a breach <2 mm (relative accuracy of 97.56%). No difference was found among groups in terms of absolute or relative accuracy (P=0.06 and P=0.23, respectively). CONCLUSIONS: AIS cases assisted by senior residents have longer operative time and higher blood loss, but this does not negatively affect the overall radiographic outcome and does not place the patient at increased risk of complications. LEVEL OF EVIDENCE: III.

Comparable rates of lumbar disc degeneration at long-term following adolescent idiopathic scoliosis spinal fusion extended to L3 or L4: systematic review and meta-analysis.

PURPOSE: Surgical treatment of adolescent idiopathic scoliosis (AIS) requires a careful choice of fusion levels. The usual recommendation for the selection of the lowest instrumented vertebra (LIV) for double major or thoracolumbar/lumbar (TL/L) curves falls on L3 or L4. The aim of the present study is to assess if the spinal fusion with LIV selection of L3 or L4 in AIS patients has a clinical or radiological impact in terms of degenerative disc disease (DDD) in distal unfused segments at long-term follow-up. METHODS: A systematic search of electronic databases from eligible articles was conducted. Only studies regarding long-term follow-up of AIS patients treated with spinal fusion were included. Clinical and radiographic outcomes were extracted and summarized. Meta-analysis on long-term follow-up MRI studies was performed. p value < 0.05 was considered significant. RESULTS: Fourteen studies were included, for a total of 1264 patients. Clinical assessment of included patients showed a slight tendency to have worse clinical outcomes if spinal fusion is extended to L4 rather than L3. Despite that, meta-analysis could not be performed on clinical parameters because of heterogeneity of evaluated PROMs in included studies. Magnetic resonance imaging (MRI) evaluation at long-term follow-up showed no significant difference in terms of disc degeneration rate at overall meta-analysis (p = 0.916) between patients fused to L3 and L4. CONCLUSION: The LIV selection of L3 rather than L4, according to current literature, does not prevent disc degeneration in distal unfused segments over the long term. Long-term studies of patients treated with contemporary spinal instrumentation are needed.

Frailty Influence on Postoperative Surgical Site Infections After Surgery for Degenerative Spine Disease and Adult Spine Deformity. Can a Frailty Index be a Valuable Summary Risk Indicator? A Systematic Review and Metanalysis of the Current Literature.

STUDY DESIGN: Metanalysis. OBJECTIVE: Surgical site infections (SSI) is one of the commonest postoperative adverse events after spine surgery. Frailty has been described as a valuable summary risk indicator for SSI in spine surgery. The aim of this metanalysis is to evaluate the influence of frailty on postoperative SSI in this cohort and provide hints on which index can predict the risk of SSI. METHODS: Papers describing the postoperative SSI rate in adult degenerative spine disease or adult spine deformity patients with varying degrees of frailty were included in the analysis. The SSI rate in different grades of frailty was considered for outcome measure. Meta-analysis was performed on studies in whom data regarding patients with different levels of frailty and occurrence of postoperative SSI could be pooled. P < .05 was considered significant. RESULTS: 16 studies were included. The frailty prevalence measured using mFI-11 ranged from 3% to 17.9%, these values were inferior to those measured with mFI-5. Significant difference was found between frail and non-frail patients in postoperative SSI rate at metanalysis (z = 5.9547, P < .0001 for mFI-5 and z = 3.8334, P = .0001 for mFI-11). CONCLUSION: This is the first meta-analysis to specifically investigate the impact of frailty, on occurrence of SSI. We found a relevant statistical difference between frail and non-frail patients in SSI occurrence rate. This is a relevant finding, as the ageing of population increases alongside with spine surgery procedures, a better understanding of risk factors may advance our ability to treat patients while minimizing the occurrence of SSI.

Restoration of Spinopelvic Alignment After Reduction of High-grade Spondylolisthesis: Myth or Reality? A Systematic Review of the literature and Meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis of literature. OBJECTIVE: The aim of the presented study is to assess whether the reduction of high-grade spondylolisthesis (HGS) through the correction of lumbosacral kyphosis leads to a decrease in the sagittal spinopelvic compensatory mechanisms. SUMMARY OF BACKGROUND DATA: HGS is as an anterior translation of a vertebra, >50%. It is also characterized by a kyphotic deformity of the affected level. This combination of translation and kyphosis leads to compensatory mechanisms on the sagittal plane [pelvic retroversion, increased lumbar lordosis (LL), reduction in thoracic kyphosis (TK)]. METHODS: A systematic search of electronic databases was conducted. Inclusion criteria were diagnosis of HGS (Meyerding >II, Slip% >50%), partial or complete reduction surgery (with a significant decrease in Slip%), and report of spinopelvic parameters (pelvic incidence, pelvic tilt, or sacral slope). Clinical and radiographic outcomes were extracted and summarized. Meta-analyses were performed to estimate the differences between preoperative and postoperative spinopelvic alignment measures. P<0.05 was considered significant. RESULTS: Eighteen studies were included. PT showed a statistically significant decrease of -2.1217 (95% CI: -3.4803 to -0.7630), while SS showed a significant increase of 4.8349 (95% CI: 2.7462-6.9236). Conversely, both LL and TK showed nonsignificant changes, -4.7043 (95% CI: -10.4535 to 1.0449) and 6.3881 (95% CI: -0.8344 to 13.6106), respectively. VAS significantly decreased by -3.1950 (95% CI: -4.9462 to -1.4439). CONCLUSIONS: The meta-analysis showed mild, yet statistically significant, decrease of PT and an increase in SS after HGS reduction. Conversely, nonstatically significant decrease in LL and an increase in TK occurred. The clinical significance of these results remains questionable. LEVEL OF EVIDENCE: Level IV.

What's the evidence on surgical treatment for congenital brachymetatarsia: A systematic review and meta-analysis.

Purpose: Brachymetatarsia is marked by the shortened length of one or more metatarsal bones. Several operative options have been suggested without demonstrating the superiority of one treatment over another. This study aims to assess the main available treatment, bone lengthening achieved, clinical outcomes, and complications pertaining to congenital brachymetatarsia interventions. Methods: A literature search of PubMed, Embase, Scopus, and Cochrane databases was performed according to PRISMA guidelines. Result: After the screening process, 13 articles were included in the review. Brachymetatarsia mainly occurs in females at a ratio of 14.8:1, and bilateral involvement in 25.8 % of cases. The fourth metatarsal is most affected, followed by the first metatarsal. The main surgical procedures are one-stage approach which results in limited length gain but fewer complications, and gradual lengthening which achieves greater length but has a higher complication rate, including metatarsophalangeal or interphalangeal subluxation, fractures, and infections. The first metatarsal reported better values concerning lengthening rate and healing index compared to fourth metatarsal, while no differences were observed in distraction rates or clinical outcomes. More complications, such as stiffness, fractures, and cavus foot were associated with first metatarsal lengthening. Conclusions: It is not possible to identify a gold standard technique for addressing this condition. The two predominant surgical techniques bear advantages and drawbacks. A judicious case-by-case assessment is mandatory to determine the optimal surgical approach. Exploring the combination of techniques could be promise in mitigating the limitations associated with the main two methods and achieving better forefoot balance. Level of evidence: Level II, systematic review.

Unveiling Timetable for Physical Therapy after Single-Level Lumbar Surgery for Degenerative Disc Disease: Insights from a Systematic Review and Meta-Analysis.

Background: Postoperative physical therapy emerges as a pivotal element of the rehabilitation process, aimed at enhancing functional recovery, managing pain, and mitigating the risk of further complications. The debate concerning the optimal timing of physical therapy intervention post-surgery remains unresolved; in particular, whether to initiate physical therapy immediately or to wait weeks is of particular interest. The aim of this study is to review the available literature regarding the optimal timing of physical therapy initiation and the outcomes obtained. Methods: This review was carried out in accordance with the Preferential Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. This search was carried out in February 2024. Only peer-reviewed articles were considered for inclusion. Results: Fourteen studies were included. The primary outcomes assessed in the included studies were the following: 12-week and 12-month low back pain, return to work, function and disability, psychological status, patient satisfaction, and complications associated with early physical therapy. A meta-analysis was performed concerning low back pain after lumbar discectomy at 12 weeks and 12 months and complications after early physical therapy after lumbar discectomy and lumbar interbody fusion. A significant difference was found between early and standard physical therapy in terms of low back pain at 12-18 months (p = 0.0062); no significant differences were found in terms of complications, both for discectomy and arthrodesis. Conclusions: This review indicates that employing early rehabilitation strategies for intervertebral disc disease could enhance results in terms of pain and disability without an enhanced risk of complications.

Similar Short-Term Outcomes of Adolescent Idiopathic Scoliosis Surgery with or without Drainage: A Systematic Review of the Literature and Meta-Analysis.

The use of closed suction drains post posterior spinal fusion for adolescent idiopathic scoliosis (AIS) is common practice, although evidence on its impact is limited compared to that for knee and hip arthroplasty. This study aimed to assess the effect of closed suction drainage on short-term post-operative outcomes in AIS surgery. A systematic review following PRISMA guidelines was conducted, including studies comparing outcomes with and without drainage. Data on blood loss, transfusions, hospital stay, and complications were collected and subjected to meta-analysis. Five studies involving 772 patients were analyzed. The meta-analysis found no significant difference in blood transfusion rates (p = 0.107) or hospital stay (p = 0.457) between groups. Complications, including surgical site infections, were more common without drainage, though not statistically significant (p = 0.356). Reintervention rates were higher in the no-drainage group, but not significantly (p = 0.260). Overall, this review found no significant short-term outcome differences, suggesting clinical judgment should guide drainage decisions. Further research, particularly with enhanced recovery protocols, is warranted to clarify drainage's role in AIS surgery.

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.

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.

Risk factors for postoperative coronal imbalance after surgical correction of adult spinal deformities: a systematic review with pooled analysis.

OBJECTIVE: The aim of this study was to identify preoperative risk factors for postoperative coronal imbalance (CIB) in patients undergoing surgical correction for adult spinal deformity (ASD). METHODS: A systematic search of articles about risk factors for postoperative CIB was conducted on electronic databases (PubMed, EMBASE, and Cochrane Library) according to the PRISMA guidelines. The methodological quality of the included articles was assessed using the Institute of Health Economics Quality Appraisal Checklist for Case Series Studies. Data regarding the patient population (demographics, diagnosis, and follow-up), pre- and postoperative radiographic and clinical data, surgical procedure details, and complications were extracted and summarized. Meta-analyses were performed when possible. RESULTS: Nine studies comprising 838 patients were included. The pooled incidence of postoperative CIB was 26%; preoperative sagittal vertical axis (SVA) and type C imbalance (trunk shifted toward the convexity) were found to be the only primary risk factors for iatrogenic CIB (p < 0.001 and p = 0.012, respectively). CONCLUSIONS: Baseline evaluation of a patient's global alignment is of outmost importance when planning surgery for ASD. Type C coronal imbalance (trunk shifted toward the convexity of the main curve) and increased preoperative SVA put the patient at risk of postoperative CIB. Intraoperatively, care should be taken to properly correct the lumbosacral fractional curve.