Quantitative assessment of muscle activity of back and lower extremities, whole body sagittal alignment, body sway, and health-related quality of life in adult spinal deformity patients before and after spinopelvic correction surgery: From the standpoint of the "cone of economy".

BACKGROUND AND AIMS: Pain and muscle fatigue in the low back and lower extremity associated with adult spinal deformity (ASD) markedly limit daily activities and affect quality of life. This study aimed to clarify if spinal correction surgery decreases the muscle activity requirements in relation to alignment and balance parameters. METHODS: Integrated electromyogram (I-EMG) studies of the low back and lower extremity in addition to whole body alignment, body sway, and health-related quality of life (HRQOL) were evaluated in 16 patients with ASD before and after surgery. Sixteen healthy volunteers were included as control subjects. Muscle activities of the bilateral lumbar paravertebral, biceps femoris, rectus femoris, gastrocnemius, and tibialis anterior were measured using surface electromyogram in both resting and working standing positions. Surgical outcomes were based on improvements in muscle fatigue using the sum of the whole muscle I-EMGs and body sway. HRQOL was evaluated by SRS-22r, which measures 4 domains (function, pain, self-image, mental health) and subtotal scores. RESULTS: In controls, the sum of the 10 whole I-EMGs (mVms; mean ± SD) was 3316 ± 1247 in the resting standing position and 5625 ± 2065 in the working standing position. The I-EMG values were higher in ASD patients than in healthy subjects; in the resting standing position, the sum of the whole 10 I-EMGs significantly decreased from baseline (9125 ± 3529) to 3 (6088 ± 1793) and 6 (6381 ± 1776) months postoperatively (p < 0.01). In the working standing position, the sum in ASD patients also significantly decreased from baseline (14,160 ± 5474) to 3 (8085 ± 2540) and 6 (8557 ± 3025) months postoperatively (p < 0.01). I-EMG values did not differ significantly between the 3- and 6-month time points in either condition. Body sway was also improved postoperatively at 3 months and maintained at 6 months along with the amelioration of whole-body sagittal alignment, and 4 domains and subtotal SRS-22r scores significantly increased postoperatively. CONCLUSION: Following spinopelvic correction surgery, whole body sagittal alignment was improved, and muscle activity based on I-EMG and body sway were significantly decreased. The SRS-22r scores after surgery also indicated significant improvement, suggesting that muscle fatigue in the standing position was ameliorated, i.e., the "cone of economy" was normalized.

Learning curve associated with minimally invasive surgery for hallux valgus: A systematic review.

BACKGROUND: The purpose of this systematic review is to examine the learning curve associated with minimally invasive surgery (MIS) for the treatment of hallux valgus (HV). METHODS: A systematic review was performed using PubMed, ScienceDirect, Web of Science, CINAHL and MEDLINE databases from database inception to February 16th, 2023. Inclusion criteria was articles with level of evidence I-III, any outcomes associated with learning curve, minimally invasive surgery, and diagnosis of hallux valgus' in adult patients. RESULTS: Six articles out of 165 articles meet inclusion criteria. For all six articles, 368 total patients (422 total feet) were included in the study with an average age of 55.69 years. Three studies reported the number of surgeries needed to reach the plateau phase of the learning curve of MIS for HV, with a frequency weighted mean of 35.5 surgeries (range 27 - 40). In the selected articles, significant results were found for increased operating room (OR) time and fluoroscopy shots in the learning phase. There was no significant increase in complications in the learning phase. There was no significant decrease in patient outcomes, or the quality of correction performed during the learning phase. CONCLUSION: An average of 35.5 surgeries (range 27 - 40) are needed to reach the plateau phase for MIS for HV. The learning phase of the learning curve of MIS for HV has a significant increase in OR time and fluoroscopy usage. However, the learning phase of the learning curve of MIS for HV is not associated with decreased outcomes or higher complication rates based on the small sample size in this study. LEVEL OF EVIDENCE: Level III, Systematic Review.

L5 pedicle subtraction osteotomy maintains good radiological and clinical outcomes in elderly patients with a rigid kyphosis deformity: a more than 2-year follow-up report.

PURPOSE: L5 pedicle subtraction osteotomy (PSO) is a demanding technique; thus, PSOs are usually performed at the L3/L4 level to correct the lack of lumbar lordosis. Mid- to long-term improvements in clinical outcomes after L5 PSO are unknown. We aimed to determine the efficacy and safety of L5 PSO for rigid kyphosis deformities. METHODS: We retrospectively reviewed the records of 57 patients with a rigid kyphosis deformity (mean age: 68 years) who underwent extensive corrective surgery incorporating PSO with a > 2-year follow-up. Radiographic parameters, postoperative complication rates, and the Oswestry Disability Index (ODI) scores were compared in the L5, L4, and L1-3 PSO groups preoperatively and at 1, 2, and 5 years postoperatively. RESULTS: There were 12, 25, and 20 patients in the L5, L4, and L1-3 PSO groups, respectively. Significant between-group differences were found in preoperative L4-S1 lordosis (L5:L4:L1-3 PSO groups = - 8.9°:8.9°:16.2°, P < 0.001). The surgeries improved the postoperative spinopelvic alignment (similar in all groups). There was no significant between-group difference in the postoperative complication rate; no irreversible complications occurred. In the L5 PSO group, there was one case of a common iliac vein injury. The ODI scores improved postoperatively in all groups; this was maintained for 5 years postoperatively. CONCLUSION: L5 PSO for L4-5/L5 kyphosis deformities resulted in adequate correction and ODI improvement, which were maintained up to 5 years postoperatively. The surgical invasiveness, complication rates, and long-term prognosis associated with L5 PSO were similar to those of PSOs performed at other levels.

Intraoperative neurophysiological monitoring during scoliosis surgery in patients with Duchenne muscular dystrophy.

PURPOSE: Little is known about the reliability and value of intraoperative neurophysiological monitoring (IONM) in patients with Duchenne muscular dystrophy (DMD) undergoing scoliosis correction surgery. The aim of this study was to investigate the feasibility of IONM and the cortical excitability in these patients. METHODS: Fifteen patients with DMD and scoliosis and 15 patients with adolescent idiopathic scoliosis (AIS) underwent scoliosis correction surgery with the use of IONM. IONM consisted of transcranial electrical stimulation motor evoked potential (Tc-MEP) and somatosensory evoked potential (SSEP) monitoring. The highest Tc-MEP amplitudes were collected to test the feasibility. Preoperative compound muscle action potentials (CMAPs) and transcranial magnetic stimulation (TMS)-MEPs were recorded to test the cortical excitability. SSEPs were scored as elicitable or not elicitable. RESULTS: Tc-MEP amplitudes were significantly lower in the DMD group for both the gastrocnemius and tibialis anterior muscles. However, the abductor hallucis muscle had similar amplitudes in both the DMD as the AIS group. TMS/CMAP and Tc-MEP/CMAP ratios were similar in the DMD and AIS group (P = 0.126 and P = 0.792 respectively). CONCLUSIONS: Tc-MEP and SSEP monitoring is feasible, particularly when Tc-MEPs are recorded from the abductor hallucis muscle in patients with DMD. Similar TMS/CMAP and Tc-MEP/CMAP ratios show that there were no differences observed in cortical excitability between the groups. IONM seems a feasible and valuable neurophysiological tool to signal possible surgically induced damage to the spinal cord during scoliosis correction surgery in patients with DMD.

[Clinical efficacy of short-term halo-pelvic traction combined with surgery in the treatment of severe spinal deformities].

OBJECTIVE: To evaluate the clinical efficacy of short-term halo-pelvic traction (HPT) combined with surgery in the treatment of severe spinal deformities. METHODS: In the study, 24 patients diagnosed as severe spinal deformity accepted the treatment of one-stage short-term HPT and two-stage surgery from January 2015 to May 2018 in our orthopedics department. 24 cases (9 males and 15 females) were retrospectively reviewed. The average age of the cohort was (28.8±10.0) years (12－48 years). The height, scoliosis angle, kyphosis angle, the height difference of shoulders, the height difference of crista iliaca, C7PL-CSVL and the perpendicular distance of S1 and the convex point of the patients were assessed at pre-traction, post-traction and post-surgery. The paired t test was used to analyze the difference among pre-traction, post-traction and post-surgery. RESULTS: The average traction time of 24 cases was (2.5±1.1) weeks (1－5 weeks). The height of pre-traction and post-traction were (141.7±11.2) cm (116-167 cm) and (154.1±9.5) cm (136－176 cm) respectively, showing significant difference (P < 0.05), and the increased height was (12.4±4.6) cm (4－20 cm). The average scoliosis angle before traction was 104.9°±35.0°(25°ï¼158°), and it was significantly decreased in post-traction[64.8°±21.0°(19°ï¼92°)] and post-surgery[39.3°±17.0° (10°-70°)] (P < 0.05). The traction's coronal correction rate was 37.2%±10.9% (11.9%－51.2%) and the total coronal correction rate was 61.9%±12.6%(26.9%-79.0%). The average kyphosis angle before traction was 106.9°±29.2°(54°ï¼163°), and it was significantly decreased in post-traction [63.1°±17.1°(32°ï¼92°)] and post-surgery [39.0°±16.8°(10°ï¼68°)](P < 0.05). The traction's sagittal correction rate was 40.0%±10.7%(16.7%－55.5%) and the total sagittal correction rate was 64.3%±10.7%(49.0%－87.5%). The average C7PL-CSVL before traction was (3.2±2.8) cm, and it was significantly decreased in post-traction [(2.5±2.5) cm] (P < 0.05). The perpendicular distance of S1 and the convex point before traction was (10.5±4.8) cm, and it was significantly decreased in post-traction[(8.4±3.5) cm] (P < 0.05). CONCLUSION: The one-stage short-term HPT combined with two-stage surgery is a safe and effective procedure for severe spinal deformities. The clinical efficacy is satisfactory and the complication is relatively less.

Risk Factors for Wound Infections after Deformity Correction Surgery in Neuromuscular Scoliosis.

OBJECTIVE: This study aims to elucidate surgical risk factors in neuromuscular scoliosis (NMS) with respect to wound site infection after spinal fusion. METHODS: A retrospective review was performed of all patients treated surgically for NMS between January 2008 and December 2016 (minimum 6 months' follow-up). A sub-cohort of 60 patients with minimum 2 years of follow-up data was also analyzed. RESULTS: In 102 patients (53 boys and 49 girls), the mean age at surgery was 14.0 years (SD ±2.7). Mean follow-up was 2.53 years (±1.66), and mean time to presentation of infection was 2.14 months (±4.95). The overall perioperative complication rate was 26.5%, with 14.7% of patients developing deep wound infection. Gram-negative bacteria were responsible for 60% of infections; 20% were Gram positive, and 20% involved both types. Pulmonary comorbidities (p = 0.007), pre- to postoperative increase in weight (p = 0.010), exaggerated lumbar lordosis at follow-up (p = 0.008), history of seizures (p = 0.046), previous myelomeningocele repair (p = 0.046), and previous operations (p = 0.013) were significant risk factors for infection. CONCLUSION: Our data suggest that in the pediatric population treated surgically for NMS, wound infection is strongly associated with postoperative increase in body weight, residual lumbar lordosis, pulmonary comorbidity, history of myelomeningocele repair, seizures, and previous operations.

Secondary Revision of Female Hairline Correction Surgery: Personal Experience.

Patients undergoing secondary female hairline correction surgery present with dissatisfaction of various causes that require specific solutions. Satisfactory results following secondary revision surgery are achieved only after consideration of the reasons for the patient's dissatisfaction as well as specific factors regarding the state of the hairline, height and width of the forehead, and overall facial type; all of these must be considered when choosing the most suitable surgical method. In the present study, the authors used various surgical approaches according to the patient's characteristics and presenting symptoms in the performance of secondary hairline correction surgery and evaluated the adequacy of each method using a satisfaction survey. In total, 246 patients who underwent hairline correction surgery by hair transplantation were enrolled in this study. As adjunctive procedures prior to surgery, 24 patients received triamcinolone injections every 1-2 weeks to ameliorate severe hyperfibrotic scarring, and laser hair removal was performed in part of the recipient area in 18 patients to remove old transplanted grafts that had created an awkward appearance or were unnecessary. Revision of female hairline correction surgery was performed with FUT (follicular unit transplantation) in 156 patients (63.4%), partial-shave FUE (follicular unit extraction) in 12 patients (4.9%), a combination technique (FUT + FUE) in 24 patients (9.8%), and non-shaven FUE in 54 patients (22.0%). LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Cervical kyphosis in patients with Lenke type 1 adolescent idiopathic scoliosis: the prediction of thoracic inlet angle.

BACKGROUND: Several studies have explored cervical kyphosis (CK) in adolescent idiopathic scoliosis (AIS) patients. However, few studies have evaluated the cervical alignment in these patients according to their coronal curve type. The aim of this study was to analyze the radiological features of cervical sagittal alignment in Lenke 1 AIS patients before and after surgery. METHODS: This is a retrospective study enrolled 50 patients. Preoperative and postoperative standing full-length radiographs (at last follow-up after operation) were used to measure the coronal and sagittal parameters. Main sagittal parameters included C2-C7 angle, thoracic inlet angle (TIA), T1 slope, proximal thoracic kyphosis (PTK, T1-5 kyphosis) and thoracic kyphosis (TK, T5-12 kyphosis). RESULTS: The TIA of patients with CK was significantly smaller than that of patients with CL (63.0° vs. 76.3°, p < 0.05) and the cutoff value was 71°. The TIA of patients with CK after surgery was significantly smaller than that of patients with CL postoperatively (62.5° vs. 74.6°, p < 0.05) and the cutoff value was 62°. In patients with postoperative CL, there was a significant increase in their PTK and a reduction in their TK, regardless of preoperative CL or CK. In patients whose CL deteriorated to CK after surgery, both their PTK and TK significantly decreased after surgery. CONCLUSIONS: Patients with TIA less than 71° were more likely to have CK. And patients with TIA less than 62° would lead to the postoperative uncorrected or new onset of CK. The increased PTK after operation could have a beneficial effect on the improvement of CL.

[Factors correlated with height gain after posterior spinal correction surgery in lenke 1 adolescent idiopathic scoliosis].

Objective: To investigate the correlated factors of height gain (ΔSH) after posterior spinal correction surgery in Lenke 1 adolescent idiopathic scoliosis (AIS), and to propose the predictive model of ΔSH. Methods: From 2013 to 2015, a total of 150 Lenke 1 AIS patients undergoing posterior spinal correction surgery were included in the study, with the age of (14.3±2.9) years. The Cobb angle of major curve, thoracic kyphosis (TK) and lumbar lordosis (LL) were measured on both pre-op and post-op standing whole spine x-rays. The change in Cobb angle, TK and LL were calculated. The difference between pre-operation and post-operation was compared and the linear regression analysis was used for the predictive model of ΔSH. Results: The pre-op and post-op values were (41.6±3.0)cm and (43.9±2.7)cm for spinal height (SH)[ΔSH=(2.4±0.8)cm, P=0.000]; (50.5±10.4)° and (14.6±6.4)° for Cobb angle (P=0.000). The Pearson correlation analysis showed that ΔSH was significantly correlated with pre-op SH (P=0.000), pre-op Cobb angle (P=0.000), pre-op TK (P=0.000), post-op SH (P=0.020), post-op Cobb angle (P=0.000), change in Cobb angle (P=0.000) and change in TK (P=0.000). The linear regression model 1 revealed that ΔSH was linearly correlated with change in Cobb angle (P=0.000) as well as change in TK (P=0.000); the linear regression model 2 showed that the pre-op Cobb angle (P=0.000) and pre-op TK (P=0.020) could be used for the pre-op prediction of ΔSH. Conclusions: The positively correlated factors of ΔSH include pre-op and post-op Cobb angle, TK, change in Cobb angle and change in TK. High pre-op Cobb angle and TK indicates high height gain in Lenke 1 AIS patients.

Occurrence of Dysphagia After Correction Surgery in the Cervical Spine for Dropped Head Syndrome.

Correction surgery for dropped head syndrome (DHS) is a challenging procedure that requires extensive realignment of the cervical spine and is associated with a high rate of complications. Postoperative occurrence of dysphagia related to the change of the cervical alignment is well known as a complication of occipito-cervical fusion, and it is thought to be caused by narrowing of the pharyngeal airway space (PAS) due to the change of the alignment. We experienced a case of severe dysphagia requiring tracheotomy and gastrostomy after correction surgery for DHS. Revision surgery which downgraded the cervical lordosis immediately solved this problem. We report this case and discuss the possible risk factors causing this complication.

Correlation analysis and clinical significance of changes in upper thoracic vertebra tilt and clavicle angle pre- and post-operation.

The imbalance of the lateral shoulder is reflected by the clavicle angle (CA) in radiology. It remains unclear how to achieve postoperative lateral shoulder balance (LSB) after spinal deformity correction surgery. A retrospective analysis was conducted on AIS patients who underwent surgery by the same spine surgeon at our hospital from 2016 to 2020. A total of 110 patients with spinal deformity were included in the study to verify the correlation between the T1-T5 tilt angle and CA before and after surgery, as well as the relation-ship between the change in T1-T5 tilt angle before and after surgery and the change in CA before and after surgery. By comparing the correlation coefficients, it was found that there may not be a direct relationship between the pre- and postoperative tilt angles of T1-5 and CA, but their changes were closely related to the changes in CA. The change in T1 tilt angle after orthopaedic surgery was significantly correlated with the change in CA, with a correlation coefficient of 0.976, indicating a close relationship between T1 and the clavicle. As the vertebrae moved down, the correlation gradually decreased. In summary, this study suggests that there is a close relationship between T1-T5 and the clavicle and that the change in T1 tilt angle after spinal scoliosis correction surgery is significantly correlated with CA, which decreases as the vertebra moves down.

Return to Sport after Adolescent Idiopathic Scoliosis (AIS) Correction Surgery: A Retrospective Data Analysis.

Sports are relevant to younger populations in society. Adolescent idiopathic scoliosis (AIS) patients who undergo surgical correction of the spine are often intensively involved in sports. For that, returning to the sport is often an important concern for the patients and their families. To the best of our knowledge, there is still a lack of scientific data indicating established recommendations about the time of returning to sport activities after surgical spinal correction. The aim of this study was to investigate (1) when AIS patients return to athletic activities after a posterior fusion, and (2) if they change their activities postoperatively. Furthermore, another question was (3) if the length of the performed posterior fusion or (4) fusion to the lower lumbar spine could have an influence on the rates or time of returning to sport activities postoperatively. Data collection was performed using questionnaires assessing patients' contentment and athletic activity. Athletic activities were categorized into three categories: (1) contact, (2) contact/non-contact and (3) non-contact sports. The intensity of exercised sports, the time of returning to the sport and changes in sport habits were documented. Radiographs were evaluated pre- and postoperatively to determine the Cobb angle and the length of the posterior fusion via the identification of the upper (UIV) and lower instrumented vertebra (LIV). Stratification analysis due to the fusion length was performed to answer a hypothetical question. This retrospective survery of 113 AIS patients treated with a posterior fusion revealed that, on average, returning to sport activities required 8 months of postoperative rest. The preoperative to postoperative rate of patients participating in sport activities increased from 88 (78%) to 94 (89%). Furthermore, postoperatively, a relevant shift of exercised activities from contact to non-contact sports was noted. Further subanalysis revealed that only 33 subjects were able to return to exactly the same athletic activities as before surgery (10 months postoperatively). The assessment of radiographs revealed that in this study group, the length of the performed posterior fusion and fusions to the lower lumbar spine had no influence on the time of return to athletic activities. The results of this study might shed some light on postoperative recommendations for sport activities after AIS treatment with a posterior fusion and may be beneficial for surgeons treating patients.

Radiographical Results of Adolescent Idiopathic Scoliosis with Major Curve at Proximal Thoracic Spine.

Introduction: Adolescent idiopathic scoliosis (AIS) with a major curve at the main thoracic (MT) area is classified as Lenke type 1, 2, or 3 depending on the flexibility of the proximal thoracic (PT) curve and lumbar curve. No definite classification has been established for a major curve at the PT spine. The purpose of this study is to investigate the radiographic characteristics before and after correction surgery for AIS with a major curve at the PT area. Methods: This is a retrospective cohort study at a single academic institution. Twelve patients with a major curve at the PT spine participated in our study and followed for at least two years after surgery. We evaluated the pre- and postoperative Cobb angles of the curve, curve range, location of the apex, sagittal parameters, and shoulder balance-related parameters. All patients were treated by posterior correction and fusion surgery using pedicle screw constructs. Results: The patients were classified as having a double-curve (DC) type, in which the MT curve was structural, or a single-curve (SC) type, in which the MT curve was corrected to less than 25° on supine side-bending films. The mean correction rates for the PT curve were favorable in both groups (DC, 65.7%±9.6%; SC, 39.2%±4.9%). The mean Cobb angle of the lumbar curve improved in the DC group (preoperative, 17.1°±4.0°; postoperative, 5.0°±4.2°) but deteriorated in the SC group (preoperative, 7.1°±1.2°; postoperative, 12.4°±4.4°) after surgery. Conclusions: We illustrated the postoperative radiographical changes of 12 consecutive patients with the major curve at the PT curve. Although posterior correction and fusion surgery corrected the PT curve satisfactorily in both DC and SC patients, the Cobb angle of the lumbar curve deteriorated after surgery in all SC patients. Surgeons need to pay attention to the fusion area, especially LIV, when operating the SC curve type.

A Novel Method for Predicting Ideal Postoperative Upper Instrumented Vertebra Tilt to Prevent Lateral Shoulder Imbalance after Scoliosis Correction Surgery.

Lateral shoulder imbalance (LSI) is reflected radiologically by the clavicle angle (CA). How to achieve postoperative lateral shoulder balance (LSB) after scoliosis correction surgery remains unclear. In the current study, by using the preoperative upper instrumented vertebra (UIV) tilt, the CA, the flexibility between T1 and the UIV, and the ideal postoperative UIV tilt was predicted based on the following formula: ideal postoperative UIV tilt = preoperative UIV tilt-the flexibility between T1 and UIV-preoperative CA. The reliability of the formula was verified through a retrospective analysis, and 76 scoliosis patients were enrolled. The feasibility of this method was verified through a prospective analysis, and 13 scoliosis patients were enrolled. In the retrospective study, there was a significant correlation between the difference in the actual and ideal postoperative UIV tilt values and the postoperative CA, with correlation coefficients in the whole, LSI, and LSB groups of 0.981, 0.982, and 0.953, respectively (p < 0.001). In the prospective study, all patients achieved satisfactory LSB. Using the formula preoperatively to predict an ideal postoperative UIV tilt and controlling the intraoperative UIV tilt with the improved crossbar technique may be an effective digital method for achieving postoperative LSB and has important clinical significance.

[Application of a new point contact pedicle navigation template as an auxiliary screw implant in scoliosis correction surgery].

Objective: To explore the effectiveness of a new point contact pedicle navigation template (referred to as "new navigation template" for simplicity) in assisting screw implantation in scoliosis correction surgery. Methods: Twenty-five patients with scoliosis, who met the selection criteria between February 2020 and February 2023, were selected as the trial group. During the scoliosis correction surgery, the three-dimensional printed new navigation template was used to assist in screw implantation. Fifty patients who had undergone screw implantation with traditional free-hand implantation technique between February 2019 and February 2023 were matched according to the inclusion and exclusion criteria as the control group. There was no significant difference between the two groups ( P>0.05) in terms of gender, age, disease duration, Cobb angle on the coronal plane of the main curve, Cobb angle at the Bending position of the main curve, the position of the apical vertebrae of the main curve, and the number of vertebrae with the pedicle diameter lower than 50%/75% of the national average, and the number of patients whose apical vertebrae rotation exceeded 40°. The number of fused vertebrae, the number of pedicle screws, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were compared between the two groups. The occurrence of implant complications was observed. Based on the X-ray films at 2 weeks after operation, the pedicle screw grading was recorded, the accuracy of the implant and the main curvature correction rate were calculated. Results: Both groups successfully completed the surgeries. Among them, the trial group implanted 267 screws and fused 177 vertebrae; the control group implanted 523 screws and fused 358 vertebrae. There was no significant difference between the two groups ( P>0.05) in terms of the number of fused vertebrae, the number of pedicle screws, the pedicle screw grading and accuracy, and the main curvature correction rate. However, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were significantly lower in trial group than in control group ( P<0.05). There was no complications related to screws implantation during or after operation in the two groups. Conclusion: The new navigation template is suitable for all kinds of deformed vertebral lamina and articular process, which not only improves the accuracy of screw implantation, but also reduces the difficulty of operation, shortens the operation time, and reduces intraoperative bleeding.

New Effective Intraoperative Techniques for the Prevention of Coronal Imbalance after Circumferential Minimally Invasive Correction Surgery for Adult Spinal Deformity.

This study aimed to devise measures and investigate their effect on coronal imbalance (CI) after circumferential minimally invasive correction surgery (CMIS) with lateral lumbar interbody fusion and percutaneous pedicle screw for adult spinal deformity (ASD). A total of 115 patients with ASD who underwent CMIS from the lower thoracic spine to the ilium were included. Patients were stratified based on the distance between the spinous process of the upper instrumented vertebra and central sacrum vertical line (UIV-CSVL) after the first intraoperative rod application into groups P (UIV-CSVL > 10 mm, n = 50) and G (UIV-CSVL < 10 mm, n = 65). Measures to correct postoperative CI introduced during surgery, preoperative and postoperative UIV-CSVL, and changes in UIV-CSVL after various measures (ΔUIV-CSVL) were investigated in group P. Rod rotation (RR), S2 alar-iliac screw distraction (SD), and kickstand-rod (KR) technique were performed in group P. Group P was further divided into group RR (n = 38), group SD (RR and SD) (n = 7), and group KR (RR and KR) (n = 5); the ΔUIV-CSVLs were 13.9 mm, 20.1 mm, and 24.4 mm in these three groups, respectively. Postoperative C7-CSVL < 10 mm was achieved in all three correction groups. In conclusion, our measures enabled sufficient correction of the UIV-CSVL and are useful for preventing CI after CMIS for ASD.

Surgical Approaches and Short-Term Results of Circumferential Minimally Invasive Correction Surgery for Adult Idiopathic Scoliosis.

OBJECTIVE: We present the surgical approaches and short-term (2 years postoperative) results pertaining to circumferential minimally invasive spine surgery (CMIS) with lateral lumbar interbody fusion (LLIF) and percutaneous pedicle screw application for adult idiopathic scoliosis (AS). METHODS: We enrolled eight patients with AS who underwent CMIS (2018-2020) and examined the number of fused levels, upper instrumented vertebra, lower instrumented vertebra, number of LLIF-treated segments, number of preoperative intervertebral fusions, intraoperative blood loss, operative time, various spinopelvic parameters, Oswestry Disability Index, low back pain, visual analog scale (VAS), leg VAS, bone fusion rate, and perioperative complications. RESULTS: The upper instrumented vertebra was T4, T7, T8, and T9 in two cases, whereas lower instrumented vertebra was the pelvis in all the cases. The average numbers of fixed vertebrae and segments that underwent LLIF were 13.3 ± 2.0 and 4.6 ± 0.7, respectively. All spinopelvic parameters improved significantly after surgery (thoracic kyphosis: P < 0.05, lumbar lordosis, cobb angle, pelvic tilt, pelvic incidence-lumbar lordosis, sagittal vertical axis: P < 0.001), and good alignment was achieved. The Oswestry Disability Index and VAS scores improved significantly (P < 0.001). The bone fusion rates achieved in the lumbosacral and thoracic spine were 100% and 88%, respectively. Only 1 patient showed postoperative coronal imbalance. CONCLUSIONS: The 2-year postoperative results of CMIS for AS were good, and spontaneous bone fusion was confirmed in the thoracic spine without bone grafting. In this procedure, sufficient intervertebral release with LLIF and a percutaneous pedicle screw device translation technique enabled adequate global alignment correction. Therefore, correcting the global imbalance of the coronal and sagittal planes is more crucial than correcting scoliosis.

Strategy and Efficacy of Surgery for Congenital Cervicothoracic Scoliosis with or without Hemivertebra Osteotomy.

OBJECTIVE: Cervicothoracic scoliosis will cause severe deformities in the early stage, and its structure is complex and the surgical methods are varied. The purpose of this research is to explore the indication and analyze the corrective effect of the two different posterior approach surgical strategies, including correction with fusion and hemivertebra osteotomy, for congenital cervicothoracic scoliosis deformities in children and adolescents. METHODS: This was a retrospective study of 21 patients with cervicothoracic scoliosis who received surgical treatment from January 2010 to June 2020, including nine cases of posterior hemivertebra osteotomy and fusion surgery and 12 cases of posterior correction and fusion alone. The Cobb angle, T1 tilt angle, clavicular angle, neck tilt angle, radiographic shoulder height, sagittal vertical axis, coronal balance distance, and local kyphosis angle were measured preoperatively, postoperatively, and at the last follow-up. Posterior approach hemivertebra resection or correction with fusion surgery was adopted based on the different individual characteristics of deformity such as main curve Cobb angle, growth potential, and flexibility. Patients were divided into two groups (osteotomy group and nonosteotomy group) according to whether a hemivertebra osteotomy was performed, and the corrective results in the two groups were compared. Paired-sample t tests or independent-sample t tests were used. RESULTS: The median follow-up after surgery of the 21 patients was 36 months (range, 18-72 months). The Cobb angle was corrected from 45.81° ± 14.23° preoperatively to 10.48° ± 5.56° postoperatively (correction rate, 77.78% ± 8.93%). The T1 tilt angle decreased from 15.26° ± 7.08° preoperatively to 3.33° ± 2.14° postoperatively (correction rate,73.42% ± 21.86%). The radiographic shoulder height was corrected from 1.13 ± 0.74 cm preoperatively to 0.52 ± 0.42 cm postoperatively (correction rate, 39.51% ± 35.65%). The clavicular angle improved from 2.52° ± 1.55° preoperatively to 1.16° ± 0.96° postoperatively (correction rate, 47.18% ± 35.84%). No significant differences were found at the last follow-up (p > 0.05). The Cobb angle of the main curve, T1 tilt angle, clavicular angle, cervical tilt angle, and shoulder height difference were similar in the two groups (p > 0.05). CONCLUSIONS: Posterior approach hemivertebra resection or correction with fusion surgery can be used in the treatment of congenital cervicothoracic scoliosis with satisfactory results, and the surgeon can make an individualized surgical plan according to individual characteristics of deformity.

The Standing and Sitting Spino-Pelvic Sagittal Alignment in Patients with Instrumented Lumbar Fusion Might Correlate with Adjacent Segment Degeneration.

OBJECTIVES: Sitting is a common weight-bearing posture, like standing, but there still lacks enough understanding of sagittal alignment in sitting position for patients after lumbar fusion. This study aimed to investigate the accommodation of fixed spine from standing to sitting position and its influence on unfused segments. METHODS: Sixty-two patients after lumbar fusion (test group) and 40 healthy volunteers (control group) were recruited in this research. All subjects underwent lateral radiographs of entire spine in the standing and sitting positions. The spinopelvic parameters including sagittal vertical axis (SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), and pelvic tilt (PT) were measured. The changes in parameters of patients between two positions were compared with control group, and patients were divided in different groups based on fusion level and their parameters were compared. RESULTS: When changing from standing to sitting positions, a forward-moving SVA and TPA were observed in both patients and control groups, accompanied by the decrease in LL, TK and increase in PT, but the changes of patients were smaller in TPA, LL, and TK (6.5° ± 7.2° vs 9.7° ± 6.0°, 7.7° ± 8.3° vs 13.6° ± 8.5°, 2.2° ± 6.5° vs 5.4° ± 5.1°, respectively, p < 0.05). Increase of PT in the lumbosacral fixation group was lower than that in the control group (4.4° ± 9.1° vs 8.3° ± 7.1°, p < 0.05). Patients who had adjacent segments degeneration (ASD) showed more kyphosis in unfused lumbar segments than the other patients (16.4° ± 10.7° vs -1.0° ± 4.8°, p < 0.05) from standing to sitting. CONCLUSIONS: The spine straightens in lumbar and thoracic curve, combined with forward-moving axis and pelvic retroversion when changing to the sitting position. However, these changes are relatively limited in patients after lumbar fusion, so the adjacent unfused lumbar segments compensate to stress during sitting and this may be related to ASD.