Purpose To retrospectively evaluate a cohort of athletically active patients who underwent surgery for adolescent idiopathic scoliosis (AIS), and to determine which clinical, surgical and anthropometric variables influenced their return to sport after surgery. Methods 112 adolescents who underwent high-density posterior fusion for AIS by a single surgeon were analyzed for clinical, surgical and demographic predictors of return to presurgical physical activity levels. Data were retrospectively collected by charts and X-rays analysis and patients interviews. Results Preoperative main curve Cobb was 64.4 ± 14.12° and obtained correction was 70.0 ± 12.5%. Included patients played many different sports (Table 4), most of all ballet (44/112, 39.2%), swimming (40/112, 35.7%) and gymnastics (32/112, 28.6%). At an average of 50.3 months follow-up, 76 (67.8%) patients returned to sports (RTS) at an equal or higher level than preoperatively. Younger age, lower Lenke curve type and lower main curve Cobb were significantly associated with RTS. As for RTS timing, patients who returned within the first 6 months were younger, with a higher Lenke and a less severe main curve, a more distal UIV and a more proximal LIV. No complications related to RTS were registered. Conclusion In conclusion, patients with adolescent idiopathic scoliosis safely returned to physical activity after surgery. Younger age, higher Lenke type and lower main curve severity predicted a quicker return to sport. However, prospective studies are needed to confirm these findings.

Proximal Junctional Disease (PJD) and Surgical Site Infection (SSI) are among the most common complications following spine surgery. Their risk factors are not fully understood. Among them, sarcopenia and osteopenia have recently been attracting interest. The aim of this study is to evaluate their influence on mechanical or infective complications after lumbar spine fusion. Patients who underwent open posterior lumbar fusion were analyzed. Through preoperative MRI, central sarcopenia and osteopenia were measured with the Psoas Lumbar Vertebral Index (PLVI) and the M-Score, respectively. Patients were stratified by low vs. high PLVI and M-Score and then by postoperative complications. Multivariate analysis for independent risk factors was performed. A total of 392 patients (mean age 62.6 years, mean follow up 42.4 months) were included. Multivariate linear regression identified comorbidity Index (p = 0.006), and dural tear (p = 0.016) as independent risk factors for SSI, and age (p = 0.014) and diabetes (p = 0.43) for PJD. Low M-score and PLVI were not correlated to a higher complications rate. Age, comorbidity index, diabetes, dural tear and length of stay are independent risk factors for infection and/or proximal junctional disease in patients who undergo lumbar arthrodesis for degenerative disc disease, while central sarcopenia and osteopenia (as measured by PLVI and M-score) are not.

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.

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.

Pedicle screws is the current gold standard in spine surgery, achieving a solid tricolumnar fixation which is unreachable by wires and hooks. The freehand technique is the most widely adopted for pedicle screws placing. While freehand technique has been classically performed with manual tools, there has been a recent trend toward the use of power tools. However, placing a pedicle screw remains a technically demanding procedure with significant risk of complications. The aim of this article is to retrospectively evaluate safety and accuracy of free-hand power-assisted pedicle screw placement in a cohort of patients who underwent correction and fusion surgery for scoliosis (both idiopathic and non-idiopathic) in our department. A retrospective review of all patients with scoliosis who underwent surgery and received a postoperative CT scan in our department in a 9-year period was undertaken. Screw density, number and location of pedicle screws were measured using pre and postoperative full-length standing and lateral supine side-bending radiographs. Then, postoperative CT scan was used to assess the accuracy of screw placement according to Gertzbein-Robbins scale. Malpositioned screws were divided according to their displacement direction. Finally, intra and postoperative neurological complications and the need for revision of misplaced screws were recorded. A total of 205 patients were included, with a follow-up of 64.9 ± 38.67 months. All constructs were high density (average density 1.97 ± 0.04), and the average number of fusion levels was 13.72 ± 1.97. A total of 5522 screws were placed: 5308 (96.12%) were grade A, 141 (2.5%) grade B, 73 (1.32%) grade C. Neither grade D nor grade E trajectories were found. The absolute accuracy (grade A) rate was 96.12% (5308/5522) and the effective accuracy (within the safe zone, grade A + B) was 98.6% (5449/5522). Of the 73 misplaced screws (grade C), 59 were lateral (80.80%), 8 anterior (10.95%) and 6 medial (8.22%); 58 were in convexity, while 15 were in concavity (the difference was not statistically significant, p = 0.33). Intraoperatively, neither neurological nor vascular complications were recorded. Postoperatively, 4 screws needed revision (0.072% of the total): Power-assisted pedicle screw placing may be a safe an accurate technique in the scoliosis surgery, both of idiopathic and non-idiopathic etiology. Further, and higher quality, research is necessary in order to better assess the results of this relatively emerging technique.

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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.

The aim of the present study is to elucidate preoperative risk factors for inadequate correction of coronal imbalance and/or creation of new postoperative coronal imbalance (iatrogenic CIB) in patients who undergo surgery for Adult Spinal Deformity (ASD). A retrospective review of adults who underwent posterior spinal fusion (>5 levels) for ASD was performed. Patients were divided into groups according to the Nanjing classification: type A (CSVL < 3 cm), type B (CSVL > 3 cm and C7 plumb line shifted to major curve concavity), and type C (CSVL > 3 cm and C7 plumb line shifted to major curve convexity). They were also divided according to postoperative coronal balance in balanced (CB) vs. imbalanced (CIB) and according to iatrogenic coronal imbalance (iCIB). Preoperative, postoperative, and last follow-up radiographical parameters and intraoperative data were recorded. A multivariate analysis was performed to identify independent risk factors for CIB. A total of 127 patients were included (85 type A, 30 type B, 12 type C). They all underwent long (average levels fused 13.3 ± 2.7) all-posterior fusion. Type C patients were more at risk of developing postoperative CIB (p = 0.04). Multivariate regression analysis indicated L5 tilt angle as a preoperative risk factor for CIB (p = 0.007) and indicated L5 tilt angle and age as a preoperative independent risk factors for iatrogenic CIB (p = 0.01 and p = 0.008). Patients with a preoperative trunk shift towards the convexity of the main curve (type C) are more prone to postoperative CIB and leveling the L4 and L5 vertebrae is the key to achieve coronal alignment preventing the “takeoff phenomenon”.