UNASSIGNED: Chin-on-chest deformity is a rare and severely disabling condition characterized by kyphotic deformity in the cervicothoracic spine. To treat this deformity, various osteotomy techniques were described.
UNASSIGNED: A comprehensive literature search of biomedical databases including MEDLINE (via PubMed), Scopus (via Elsevier), Embase (via Elsevier), and Cochrane Library in English from 1/1/1990 to 3/31/2022 was conducted using a combination of text and Medical Subject Headings (MeSH).
UNASSIGNED: The final analysis included 16 studies. All the studies were assigned a level of evidence of four. Except for two articles, all of the articles were non-comparative studies. A total of 288 patients were included in this review. Of the 288 patients, 107 underwent posterior column extension osteotomy (PCEO), 108 underwent pedicle subtraction osteotomy (PSO), and 33 underwent vertebral column resection osteotomy (VCRO). The most common osteotomy level in fifteen of the studies was C7/T1. The studies included in this review described several techniques for cervical sagittal balance correction. The range of preoperative and postoperative visual analogue scale (VAS) scores was 5.5-8.6 to 1.7-4.91, respectively. The range of preoperative and postoperative neck disability index (NDI) was 34.2-65.4 to 22.1-51.3, respectively. The most common complications were upper extremity paresthesia and hand numbness through the C8 dermatome distribution.
UNASSIGNED: Corrective osteotomies provide satisfactory results in patients with chin-on-chest deformity; however, the quality of the included studies limits the evidence.

BACKGROUND: Since its proposal, the Global Alignment and Proportion (GAP) score has been the topic of several external validation studies, which have yielded conflicting results. Given the lack of consensus regarding this prognostic tool, the authors aim to assess the accuracy of GAP scores for predicting mechanical complications following ASD correction surgery.
METHODS: A systematic search was performed using PubMed, Embase and Cochrane Library for the purpose of identifying all studies evaluating the GAP score as a predictive tool for mechanical complications. GAP scores were pooled using a random-effects model to compare patients reporting mechanical complications after surgery versus those reporting no complications. Where receiver operator curves (ROC) were provided, the area under the curve (AUC) was pooled.
RESULTS: A total of 15 studies featuring 2,092 patients were selected for inclusion. Qualitative analysis using Newcastle-Ottawa criteria revealed moderate quality among all included studies (5.99/9). With respect to sex, the cohort was predominantly female (82%). The pooled mean age among all patients in the cohort was 58.55 years, with a mean follow-up of 33.86 months after surgery. Upon pooled analysis, we found that mechanical complications were associated with higher mean GAP scores, albeit minimal (mean difference = 0.571 [ 95% CI: 0.163-0.979]; p=0.006, n=864). Additionally, age (p=0.136, n=202), fusion levels (p=0.207, n=358) and body mass index (p=0.616, n=350) were unassociated with mechanical complications. Pooled AUC revealed poor discrimination overall (AUC = 0.69; n=1206).
CONCLUSIONS: GAP scores may have a minimal-to-moderate predictive capability for mechanical complications associated with ASD correction.

The goal in this study was to compare the efficacy and safety outcomes of vertebral column decancellation (VCD) and pedicle subtraction osteotomy (PSO) for patients with ankylosing spondylitis (AS) with thoracolumbar kyphotic deformity.
This study was registered on the International Prospective Register of Systematic Reviews (PROSPERO). The authors conducted a computer search of PubMed, EMBASE, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang Database, and Wei Pu Database to collect controlled clinical studies on the efficacy and safety of VCD and PSO for patients with AS with thoracolumbar kyphotic deformity. The search covered the period from database establishment to March 2023. Two researchers screened the literature, extracted data, and evaluated the risk of bias of the included studies; these researchers recorded the authors and the sample size, and they extracted data on the intraoperative blood loss, Oswestry Disability Index, spine sagittal parameters, operation time, and complications in each study. Meta-analysis was performed using RevMan 5.4 software provided by Cochrane Library.
A total of 6 cohort studies with a total of 342 patients were included in this study, including 172 patients in the VCD group and 170 patients in the PSO group. The VCD group had lower intraoperative blood loss than the PSO group (mean difference [MD] -274.92, 95% CI -506.63 to -43.20, p = 0.02); significant correction of the sagittal vertical axis compared with the PSO group (MD 7.32, 95% CI -1.24 to 15.87, p = 0.03), and the operation time was shorter than that of the PSO group (MD -80.28, 95% CI -150.07 to -10.48, p = 0.02).
This systematic review and meta-analysis showed that VCD had more advantages than PSO in correcting the sagittal imbalance in the treatment of AS with thoracolumbar kyphotic deformity, and VCD had less intraoperative blood loss, shorter operation time, and satisfactory results in improving the quality of life.

The aim of our study is to analyse mid- to long-term severe adult spinal deformity (ASD) surgery outcomes by comparing three-column osteotomies (3CO) and multiple anterior interbody fusion cages (AC).
The PRISMA flowchart was used to systematically review the literature. Only articles with a minimum 24-month follow-up were examined, and 11 articles were included. The following radiological parameters were observed: pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), sagittal vertical axis (SVA), Cobb angle and T1-sacrum plumbline. Clinical outcome was assessed using the visual analogue scale (VAS) and Oswestry disability index (ODI) scores. The main complications were analysed, and the two groups were compared.
Except for age, the two populations were homogeneous. Both techniques had the same number of posterior instrumented levels (7.4 ± 1.7). The AC group had a mean 3 ± 1.4 interbody fusions per patient. In the PSO group, all patients had 1 3CO and 89.8% of the osteotomies were performed at L2 or L3 vertebrae. No difference was observed between the two groups in terms of clinical outcomes. Both techniques were effective in sagittal parameters restoration with a final PI-LL mismatch = 4.4°. The PSO group had a statistically higher rate of intraoperative blood loss (p = 0.036), major complications, pseudoarthrosis and dural tears (p < 0.001).
Both PSO and multiple AC are effective in treating ASD. Multiple AC seems more suitable when treating older patients because of a lower intraoperative blood loss, lower rate of major complications and fewer number of revision surgeries.

Rigid and ankylosed thoracolumbar spinal deformities require three-column osteotomy (3CO) to achieve adequate correction. For severe and multiregional deformities, multilevel 3CO is required but its use and outcomes are rarely reported.
To describe the use of multilevel pedicle subtraction osteotomy (PSO) in adult spinal deformity (ASD) patients with severe, rigid, and ankylosed multiregional deformity.
Retrospective review of 5 ASD patients who underwent multilevel PSO for the correction of severe fixed deformity and review the literature regarding the use of multilevel PSO.
Five patients presented with spinal imbalance secondary to regional and multiregional spinal deformities involving the thoracolumbar spine. All patients underwent a single-stage two-level noncontiguous PSO, and 2 of the patients underwent a staged third PSO to treat deformity involving a separate spinal region. Significant radiographic correction was achieved with normalization of spinal alignment and parameters. Two-level PSO was able to provide greater than 80 degrees of sagittal plane correction in both the lumbar and thoracic spine. Two patients experienced new postoperative weakness which recovered to preoperative baseline at 3 to 6 mo follow-up. At most recent follow-up, 4 of the 5 patients gained significant pain relief and had improved functionality.
Noncontiguous multilevel PSO is a formidable surgical technique. Additional risk (compared to single-level 3CO) comes in the form of greater blood loss and higher risk for postoperative weakness. Nonetheless, multilevel PSO is feasible and effective for correcting severe multiplanar and multiregional ASD, and patients gain significant benefits in increased functionality and pain relief.

Systematic review and meta-analysis.
Three-column osteotomies (3-CO) have gained popularity in the last decade as part of the armamentarium for the surgical correction of sagittal imbalance in patients with adult spinal deformity (ASD). Three-column osteotomies in the form of pedicle subtraction osteotomy (PSO) may be necessary to achieve adequate correction for severe and rigid spinal deformity. Studies reporting improvement in health-related quality of life (HRQOL) with validated outcome measures after PSO surgery are sparse and currently consist of small series.
Evaluate the improvement in HRQOL measures following PSO for adult spinal deformity.
Two independent reviewers conducted a systematic review of the English literature between period 1996 and 2019 for articles reporting outcome of PSO in patients with ASD according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Inclusion criteria were studies consisting of patient-reported outcome Oswestry Disability Index (ODI) and Scoliosis Research Society 22 or 24 (SRS) outcomes after PSO surgery for adult spine deformity patients (18 years or older) with a minimum follow-up of 1 year.
Eight studies with 431 PSOs were included in the meta-analysis. The results showed a statistically significant improvement in ODI in PSO (P < 0.0001), and the mean clinically important difference was achieved with both ODI (50.46 (45.5-55.4) preoperatively to 32.78 (29.7-39) postoperatively) and SRS (2.49 (2.38-2.7) preoperatively to 3.26 (2.8-4.1) postoperatively) scores.
This meta-analysis did find improvements in the health-related quality of life in patients undergoing PSO surgery for adult spinal deformity.

To review the incidence of perioperative and late complications of surgery for spinal deformity (ASD).
Review of the literature. We reviewed recent literature in English to investigate the incidence of complications in ASD surgery in the perioperative (≤ 3 months post-operative) and late (> 3 months post-operative) periods. Randomized-controlled trials, non-randomized trials, cohort studies, case-control studies, and case series published in 2005 or later were included. We divided articles according to surgical technique: open procedures (OP), minimally invasive surgery (MIS), and hybrid procedures (HP). Complications were recorded, grouped by surgical technique, and then classified according to a proposed Grading of Incidence of Complications (IOC).
Ninety-six publications reporting on 12,168 patients were included; 68 were level IV of evidence studies, 24 were level III, and 4 level II. Perioperative IOC was 26.5% in OP, 36.4% in HP, and 24.2% in MIS. Late IOC was 11.1% in OP, 15.4% in HP, and 14.0% in MIS. IOC was significantly higher for hybrid procedures compared to both open and MIS procedures.
Reported complications of surgery for ASD in the recent literature are frequent (24-36% perioperative plus 11-15% late). Open procedures were the most extensively reported in the literature. Complication rates are similar for OP and MIS. HP presented higher IOC likely due to the combination of OP and MIS respective complications. Small number of studies and heterogeneity in reporting could result in risk of bias in these results. Large-scale registry-based studies can fill this gap in the future. These slides can be retrieved under Electronic Supplementary Material.

In the late stage of Spinal tuberculosis, the bony destruction and vertebral collapse often leads to significant kyphosis, presenting clinically as a painful gibbus deformity, with increased instability, vertebral body translations and increased risk of neurologic involvement. Vertebral column decancellation is thought to be suitable for most patients with severe rigid kyphosis. Surgimap Spine, could offer a pragmatic graphical method for the surgical planning of osteotomies. The aim of this study was to evaluate the efficacy of Vertebral column decancellation planned preoperatively with the computer software-assistance in the patients with Pott\'s kyphosis.
Between May 2012 and May 2015, 18 patients with Pott\'s kyphosis underwent the Vertebral column decancellation using Surgimap Spine for preoperative surgical planning. Preoperative and postoperative Konstam\'s angle, sagittal vertical angle, lumbar lordosis, thoracic kyphosis, pelvic tilt and pelvic incidence were measured. Visual analog scale and American Spinal Injury Association were documented.
The Konstam\'s angles decreased from 88.1° (range, 70-105°) preoperatively to 18.5° (range, 7-31°) (P < 0.01). All patients reached the physiological limits at the final follow-up. The mean VAS score was reduced from preoperative 7.1 (range, 6-8) to 1.8 (range, 1-3, P < 0.01) and the ODI improved from 65.8% (range, 58-74%) to 20.2% (range, 12-38%, P < 0.01). At final follow-up, there was radiographic evidence of solid fusion at the osteotomy site and fixed segments in all patients. Neurological function improved from ASIA scale D to E in 5 patients. The patients were followed up for 30.4 months on average.
Vertebral column decancellation is an effective treatment option for severe Pott\'s kyphosis. The surgical planning software Surgimap Spine can be a reliable and helpful tool that provides a simplified method to evaluate and analyze the spino-pelvic parameters and simulate the osteotomy procedure. According to individual character, the appropriate surgery strategy should be selected.

OBJECTIVE Although 3-column osteotomy (3CO) can provide powerful alignment correction in adult spinal deformity (ASD), these procedures are complex and associated with high complication rates. The authors\' objective was to assess complications associated with ASD surgery that included 3CO based on a prospectively collected multicenter database. METHODS This study is a retrospective review of a prospectively collected multicenter consecutive case registry. ASD patients treated with 3CO and eligible for 2-year follow-up were identified from a prospectively collected multicenter ASD database. Early (≤ 6 weeks after surgery) and delayed (> 6 weeks after surgery) complications were collected using standardized forms and on-site coordinators. RESULTS Of 106 ASD patients treated with 3CO, 82 (77%; 68 treated with pedicle subtraction osteotomy [PSO] and 14 treated with vertebral column resection [VCR]) had 2-year follow-up (76% women, mean age 60.7 years, previous spine fusion in 80%). The mean number of posterior fusion levels was 12.9, and 17% also had an anterior fusion. A total of 76 early (44 minor, 32 major) and 66 delayed (13 minor, 53 major) complications were reported, with 41 patients (50.0%) and 45 patients (54.9%) affected, respectively. Overall, 64 patients (78.0%) had at least 1 complication, and 50 (61.0%) had at least 1 major complication. The most common complications were rod breakage (31.7%), dural tear (20.7%), radiculopathy (9.8%), motor deficit (9.8%), proximal junctional kyphosis (PJK, 9.8%), pleural effusion (8.5%), and deep wound infection (7.3%). Compared with patients who did not experience early or delayed complications, those who had these complications did not differ significantly with regard to age, sex, body mass index, Charlson Comorbidity Index, American Society of Anesthesiologists score, smoking status, history of previous spine surgery or spine fusion, or whether the 3CO performed was a PSO or VCR (p ≥ 0.06). Twenty-seven (33%) patients had 1-11 reoperations (total of 44 reoperations). The most common indications for reoperation were rod breakage (n = 14), deep wound infection (n = 15), and PJK (n = 6). The 24 patients who did not achieve 2-year follow-up had a mean of 0.85 years of follow-up, and the types of early and delayed complications encountered in these 24 patients were comparable to those encountered in the patients that achieved 2-year follow-up. CONCLUSIONS Among 82 ASD patients treated with 3CO, 64 (78.0%) had at least 1 early or delayed complication (57 minor, 85 major). The most common complications were instrumentation failure, dural tear, new neurological deficit, PJK, pleural effusion, and deep wound infection. None of the assessed demographic or surgical parameters were significantly associated with the occurrence of complications. These data may prove useful for surgical planning, patient counseling, and efforts to improve the safety and cost-effectiveness of these procedures.

Deformities of the cervical spine are uncommon in the coronal plane. In this report, a unique case of a 31-year-old male with a fixed, 30° left coronal deformity due to heterotopic ossification 3 years status post poly-trauma was treated with an asymmetric C7 pedicle subtraction osteotomy (PSO).
Case report.
Pre-operatively, the patient had a fixed 45-degree left tilt of his neck and radiographs demonstrated a rigid 30° scoliosis, 7 cm coronal imbalance, and 4 cm negative sagittal balance, diffuse bridging bone between the spinous processes and the facet joints of C5 to T1 bilaterally. An asymmetric C7 PSO with C2-T3 posterior spinal fusion was completed without complication. There was residual 9° coronal deformity, 2.9 cm left coronal imbalance, and 2.3 cm sagittal imbalance. He had a marked improvement in his function, as assessed by the SF-36 physical component score (pre-op 31.1; post-op 44.7) and mental component score (pre-op 46.0; post-op 66.8). Post-operatively, neck disability index scores also improved (pre-op 38; post-op 16). Although the patient passed away from a drug overdose 14 months post-operatively, he did not report neck pain, he had not sought evaluation from another physician for his neck, and he had not undergone a subsequent neck operation before his passing.
In this one patient, an asymmetric C7 PSO was performed safely. While it was effective in addressing a fixed cervical coronal imbalance, its efficacy and safety profile should be confirmed in larger cohorts.