[Comparison of Clinical Effects of Cortical Bone Trajectory Screws and Traditional Pedicle Screws in Posterior Lumbar Fusion]. / è °æ¤ŽåŽè·¯èžåˆæœ¯ä¸­çš®è´¨éª¨è½¨è¿¹èžºé’‰å’Œä¼ ç»Ÿæ¤Žå¼“æ ¹èžºé’‰çš„ä¸´åºŠæ•ˆæžœæ¯”è¾ƒ.

Objective: To compare the clinical effects of cortical bone trajectory screws and traditional pedicle screws in posterior lumbar fusion. Methods: A retrospective study was conducted to analyze lumbar degeneration patients who underwent surgical treatment at our hospital between January 2016 and January 2019. A total of 123 patients who met the inclusion criteria were enrolled. The subjects were divided into two groups according to their surgical procedures and the members of the two groups were matched by age, sex, and the number of fusion segments. There were 63 patients in the traditional pedicle screws (PS) group and 60 in the cortical bone trajectory screws (CBTS) group. The outcomes of the two groups were compared. The primary outcome measures were perioperative conditions, including operation duration, estimated intraoperative blood loss (EBL), and length-of-stay (LOS), visual analog scale (VAS) score, Oswestry Disability Index (ODI) score, and interbody fusion rate. The secondary outcome measures were the time to postoperative ambulation and the incidence of complications. VAS scores and ODI scores were assessed before operation, 1 week, 1 month, 3 months, and 12 months after operation, and at the final follow-up. The interbody fusion rate was assessed in 1 year and 2 years after the operation and at the final follow-up. Results: The CBTS group showed a reduction in operation duration ([142.8±13.1] min vs. [174.7±15.4] min, P<0.001), LOS ([9.5±1.5] d vs. [12.0±2.0] d, P<0.001), and EBL ([194.2±38.3] mL vs. [377.5±33.1] mL, P<0.001) in comparison with the PS group. The VAS score for back pain in the CBTS group was lower than that in the PS group at 1 week and 1 month after operation and the ODI score in the CBTS group was lower than that in the PS group at 1 month after operation, with the differences being statistically significant (P<0.05). At each postoperative time point, the VAS score for leg pain and the interbody fusion rate did not show significant difference between the two groups. The VAS score for back and leg pain and the ODI score at each time point after operation in both the CBTS group and the PS group were significantly lower than those before operation (P<0.05). No significant difference was found in the time to postoperative ambulation or the overall complication incidence between the two groups. Conclusion: The CBTS technique could significantly shorten the operation duration and LOS, reduce EBL, and achieve the same effect as the PS technique does in terms of intervertebral fusion rate, pain relief, functional improvement, and complication incidence in patients undergoing posterior lumbar fusion.

Ultrasonic bone curette-assisted unilateral approach for bilateral decompression with MIS-TLIF for severe lumbar spinal stenosis.

PURPOSE: We aimed to evaluate the clinical efficacy of bilateral decompression with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) assisted by an ultrasonic bone curette (UBC) for treating severe degenerative lumbar spinal stenosis (DLSS) and traditional tool laminectomy decompression MIS-TLIF for treating severe DLSS. METHODS: The clinical data of 128 patients with single-segment severe DLSS who were admitted between January 2017 and December 2021 were retrospectively analyzed. Among them, 67 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using an ultrasonic bone curette (UBC group), whereas 61 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using traditional tools (traditional group, control). A visual analog scale (VAS) was used to evaluate back and lower limb pain before the operation,immediate postoperative, and one week, 3, 6, 12, and 24 months after the operation. Oswestry disability index (ODI) and Zurich claudication score (ZCQ) were employed to evaluate the improvement in low back and lower limb function. At the last follow-up, the Bridwell bone graft fusion standard was utilized to evaluate bone graft fusion. RESULTS: The decompression time of laminectomy was significantly shorter in the UBC group than in the traditional group (control group), and the intraoperative blood loss and postoperative drainage volume were significantly less in those in the control group (P < 0.05). The VAS, ODI, and ZCQ scores of the two groups after the operation were significantly improved compared to those before the operation (P < 0.05). The UBC group had better VAS back scores than the control group immediate postoperative and one week after the operation(P < 0.05). The UBC group had better VAS lower limb scores than the control group immediate postoperative (P < 0.05).The incidence of perioperative complications, hospitalization time, dural sac cross-sectional area (CSA), and dural sac CSA improvement rate did not differ significantly between the two groups (P > 0.05). VAS and ODI scores did not differ significantly between the two groups before,three, six months, one year, and two years after surgery (P > 0.05). The ZCQ scores did not differ significantly between the two groups before the operation at one week, six months, one year, and two years after the operation (P > 0.05). According to the Bridwell bone graft fusion standard, bone graft fusion did not occur significantly between the two groups (P > 0.05) at the last follow-up. CONCLUSIONS: UBC unilateral fenestration bilateral decompression MIS-TLIF in treating severe DLSS can achieve clinical efficacy as traditional tool unilateral fenestration bilateral decompression MIS-TLIF and reduce intraoperative blood loss and postoperative drainage. It can also shorten the operation time, effectively reduce the work intensity of the operator, and reduce the degree of low back pain during short-term follow-ups. Therefore, this is a safe and effective surgical method.

Zero-profile anchored spacer versus conventional plate-cage construct in bilevel anterior cervical discectomy and fusion: a systematic review and meta-analysis.

BACKGROUND: Zero-profile anchored spacers (ZAS) and plate-cage constructs (PCC) are currently employed when performing anterior cervical discectomy and fusion (ACDF). Nevertheless, the efficacy and safety of both devices in bilevel ACDF remain controversial. The goal of our meta-analysis is to assess the overall long-term efficacy and security among ZAS and PCC in bilevel ACDF. METHODS: A search of four electronic databases was conducted to identify researches that compared ZAS with PCC for bilevel ACDF. Stata MP 17.0 software was used for this meta-analysis. RESULTS: Nine researches with a total of 580 patients were involved. In comparison to PCC, ZAS significantly reduced intraoperative bleeding and postoperative dysphagia rates. No significant differences were found concerning operation time, JOA score, NDI score, cervical Cobb angle, fusion rates, the incidence of adjacent segmental degeneration (ASD) and implant sinking rates at last follow-up. CONCLUSION: Compared to PCC, ZAS achieved similar efficacy and security in bilevel ACDF with respect to operative time, JOA score, NDI score, cervical Cobb angle, fusion rates, implant sinking rates and ASD rates at final follow-up. It is worth noting that ZAS offered considerable benefits over conventional PCC for the reduction of intraoperative bleeding and postoperative dysphagia. Therefore, for patients requiring bilevel ACDF, ZAS seems superior to PCC. Given the limitations of our study, larger prospective randomised controlled trials are needed to establish reliable proof to consolidate our conclusions.

Dynamic cord compression induced by proximal junctional failure and loose pedicle screws after thoracolumbar fusion surgery: a case report.

BACKGROUND: One of the common mechanical complications following spinal fusion surgery is proximal junctional failure (PJF). The incidence of neurological deficit associated with PJF has been poorly described in the literature. Here, we report a case in which numbness in the lower extremities was recognized as the first symptom, but the discrepancy in the imaging findings made PJF difficult to diagnose. METHODS: A 71-year-old female underwent corrective fusion surgery. Three weeks later, she complained of persistent right leg numbness. Standing X-ray showed the back-out of the pedicle screws (PSs) in the upper instrumented vertebra (UIV), but there was no obvious evidence of cord compression on computed tomography (CT), which caused the delay of diagnosis. Five weeks later, magnetic resonance image (MRI) did not show cord compression on an axial view, but there were signal changes in the spinal cord. RESULTS: The first reason for the delayed diagnosis was the lack of awareness that leg numbness could occur as the first symptom of PJF. The second problem was the lack of evidence for spinal cord compression in various imaging tests. Loosened PSs were dislocated on standing, but were back to their original position on supine position. In our case, these contradictory images led to a delay in diagnosis. CONCLUSION: Loosened PSs caused dynamic cord compression due to repeated deviation and reduction. Supine and standing radiographs may be an important tool in the diagnosis of PJF induced by dynamic cord compression.

Complications associated with subaxial placement of pedicle screws versus lateral mass screws in the cervical spine (C2-T1): systematic review and meta-analysis comprising 4,165 patients and 16,669 screws.

Lateral mass screw (LMS) and cervical pedicle screw (CPS) fixation are among the most popular techniques for posterior fusion of the cervical spine. Early research prioritized the LMS approach as the trajectory resulted in fewer neurovascular complications; however, with the incorporation of navigation assistance, the CPS approach should be re-evaluated. Our objective was to report the findings of a meta-analysis focused on comparing the LMS and CPS techniques in terms of rate of various complications with inclusion of all levels from C2 to T1. We conducted a systematic review of PubMed and EMBASE databases with final inclusion criteria focused on identifying studies that reported outcomes and complications for either the CPS or LMS technique. These studies were then pooled, and statistical analyses were performed from the cumulative data. A total of 60 studies comprising 4165 participants and 16,669 screws placed within the C2-T1 levels were identified. Within these studies, the LMS group had a significantly increased odds for lateral mass fractures (odds ratio [OR] = 43.2, 95% confidence interval [CI] = 2.62-711.42), additional cervical surgeries (OR = 5.56, 95%CI = 2.95-10.48), and surgical site infections (SSI) (OR = 5.47, 95%CI = 1.65-18.16). No other significant differences between groups in terms of complications were identified. Within the subgroup analysis of navigation versus non-navigation-guided CPS placement, no significant differences were identified for individual complications, although collectively significantly fewer complications occurred with navigation (OR = 5.29, 95%CI = 2.03-13.78). The CPS group had significantly fewer lateral mass fractures, cervical revision surgeries, and SSIs. Furthermore, navigation-assisted CPS placement was associated with a significant reduction in complications overall.

Double Anchoring Technique of Occipito-Cervical Fixation Using Innovative Occipital Plate: A Preliminary Study.

Background: Occipito-cervical fixation (OCF) provides immediate rigid fixation to cranio-vertebral junction (CVJ); however, in current practice, the optimal occipito-cervical fixation method is arguable. Aim: The aim of this study was to test the safety and efficacy of a newly designed inside-outside occipital (OC) plate system for the treatment of cranio-vertebral junction instability. Material and Methods: Thirty-two patients of CVJ instability were treated using this new OC plate system. Safety and efficacy of this new OC plate was evaluated radiologically and clinically. Results: Follow-up period ranged from 9 to 23 months. During the follow-up, no implant failure, recurrent subluxation, or newly developed instability at adjacent levels occurred, except in one patient in whom C2 screw pullout occurred due to trauma. All patients showed a satisfactory fusion at three months follow-up examination. Conclusions: These preliminary results suggest that this OC plate system is a simple, safe, and effective method for providing immediate internal rigid fixation of the CV junction. Long-term results are needed to determine the superiority of this OC plate over other methods of occipital fixation.

Comparison of Long-Term Efficacy of MIS-TLIF Intraoperative Implants in Patients with Osteoporosis.

Osteoporosis and degenerative spinal disease are still an unsolvable surgical problem. It is still difficult to solve the complications related to postoperative osteoporosis, such as cage subsidence, displacement, and retraction. Expandable interbody cage is a recent innovation and an increasingly popular alternative to standard static cage. However, the clinical efficacy of MIS-TLIF combined with expandable cage for the treatment of osteoporosis has limited reports. The purpose of this paper was to analyze the efficacy of MIS-TLIF with expandable cage in patients with degenerative lumbar disease with osteoporosis. Patients with osteoporosis who received single-level MIS-TLIF and were followed up for at least 1 year were included. The outcome measures are as follows: clinical features, perioperative period, and neurological complications. JOA score and VAS pain score were used to analyze the improvement of patients' function. Imaging analysis included segmental lordosis (SL), lumbar lordosis (LL), intervertebral disc height (DH), and the ratio of cage height to preoperative DH (RCD). The final data analysis included 284 patients with osteoporosis. 178 patients used static cages, and 106 patients used expandable cages. There was no significant difference in baseline characteristics, surgical indexes, and JOA and VAS scores between the two groups. There was no difference in SL or LL between static group and expandable group. There was no significant difference in preoperative DH between the two groups. The RCD in the expansion group was significantly lower than that in the static group. The intraoperative and postoperative sedimentation rate in the static group was significantly higher than that in the expandable group. The use of expandable cages in MIS-TLIF has shown good results for the treatment of degenerative lumbar diseases with osteoporosis. Through appropriate surgical techniques, the expandable cage can reduce the risk of cage sinking.

Posterior minimally invasive scoliosis surgery versus the standard posterior approach for the management of adolescent idiopathic scoliosis: an updated meta-analysis.

BACKGROUND: Surgical management of adolescent idiopathic scoliosis (AIS) can be performed using standard posterior spinal fusion (PSF) or with a posterior minimally invasive approach. Minimally invasive scoliosis surgery (MISS) has several theoretical advantages, such as less tissue dissection, less blood loss, and earlier recovery. However, the difference in safety and effectiveness between MISS and PSF still needs to be clarified. This updated meta-analysis aimed to compare the outcomes of MISS and standard PSF for the management of AIS. METHODS: A comprehensive literature search of PubMed, EMBASE, MEDLINE, and Cochrane Library without time restriction was performed to identify relevant studies. MISS and PSF were compared in terms of radiographic parameters, estimated blood loss (EBL), blood transfusion rate, operative time (ORT), length of hospital stay (LOS), overall Scoliosis Research Society-22 (SRS-22) score, postoperative pain, and complication rate. RESULTS: A total of seven studies comprising 767 patients (329 MISS and 438 PSF) with AIS were included. MISS and PSF yielded comparable deformity correction at the last follow-up. There were no significant differences in the overall SRS-22 scores or complication rates between the groups. Nevertheless, greater restoration of thoracic kyphosis (WMD, 2.98; 95% CI 0.58 to 5.37, P = 0.015), less EBL (WMD, -218.76; 95% CI -256.41 to -181.11, P < 0.001), a lower blood transfusion rate (RR, 0.31; 95% CI 0.20 to 0.48, P < 0.001), a shorter LOS (WMD, -1.48; 95% CI -2.48 to -0.48, P = 0.004), less postoperative pain (WMD, 0.57; 95% CI 0.16 to 0.98, P = 0.006), and a longer ORT (WMD, 84.85; 95% CI 33.30 to 136.40, P = 0.001) were observed in the MISS group. CONCLUSION: Despite its inherent technical challenges, MISS is a feasible and effective alternative to standard PSF for AIS patients with moderate and flexible curves. MISS was associated with adequate deformity correction, better restoration of sagittal alignment, less EBL, fewer transfusions, shorter LOS, and better pain management compared to PSF. Further research is required to determine the detailed indications for the MISS procedure.

Comparison of outcomes between Zero-p implant and anterior cervical plate interbody fusion systems for anterior cervical decompression and fusion: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: The clinical outcomes of using a zero-profile for anterior cervical decompression and fusion were evaluated by comparison with anterior cervical plates. METHODS: All of the comparative studies published in the PubMed, Cochrane Library, Medline, Web of Science, EBSOChost, and EMBASE databases as of 1 October 2021 were included. All outcomes were analysed using Review Manager 5.4. RESULTS: Seven randomized controlled studies were included with a total of 528 patients, and all studies were randomized controlled studies. The meta-analysis outcomes indicated that the use of zero-profile fixation for anterior cervical decompression and fusion was better than anterior cervical plate fixation regarding the incidence of postoperative dysphagia (P < 0.05), adjacent-level ossification (P < 0.05), and operational time (P < 0.05). However, there were no statistically significant differences in intraoperative blood loss, Visual Analogue Scale, Neck Disability Index, or Japanese Orthopaedic Association scale (all P > 0.05) between the zero-profile and anterior cervical plate groups. CONCLUSIONS: The systematic review and meta-analysis indicated that zero-profile and anterior cervical plates could result in good postoperative outcomes in anterior cervical decompression and fusion. No significant differences were found in intraoperative blood loss, Visual Analogue Scale, Neck Disability Index, or Japanese Orthopaedic Association scale. However, the zero-profile is superior to the anterior cervical plate in the following measures: incidence of postoperative dysphagia, adjacent-level ossification, and operational time. PROSPERO registration CRD42021278214.

Oblique Lateral Interbody Fusion with Anterolateral Screw Fixation Is as Effective as with Posterior Percutaneous Pedicle Screw Fixation in Treating Single-Segment Mild Degenerative Lumbar Diseases.

BACKGROUND Oblique lateral interbody fusion (OLIF) is a new and minimally invasive surgery. This study aimed to compare the clinical efficacy and safety of oblique lateral interbody fusion with anterolateral screw fixation and with posterior percutaneous screw fixation in treating single-segment mild degenerative lumbar diseases. MATERIAL AND METHODS A retrospective analysis was performed on 51 patients with single-segment mild degenerative lumbar diseases who received OLIF from April 2017 to January 2020 in Hong Hui Hospital, Xi'an Jiao Tong University; 24 and 27 patients received OLIF with anterolateral screw fixation (OLIF+AF) and OLIF with posterior percutaneous screw fixation (OLIF+PF), respectively. Anesthesia time, operation time, intraoperative blood loss, intraoperative fluoroscopy number, hospital stay, postoperative complications, Visual Analog Scale (VAS) score, Oswestry Disability Index (ODI) score, anterior and posterior disc heights, foraminal height, and fusion rate of the 2 groups were compared to assess clinical and radiological outcomes. RESULTS Anesthesia time, operation time, intraoperative blood loss, number of intraoperative fluoroscopy, and VAS score in the OLIF+AF group were significantly better than those in the OLIF+PF group (P<0.05). There were no significant differences in ODI score, anterior and posterior disc heights, foraminal height, fusion rate, and incidence of complications between the 2 groups (P<0.05). CONCLUSIONS OLIF+AF in treating single-segment mild degenerative lumbar diseases produces a satisfactory clinical effect. Moreover, OLIF+AF does not invade the paraspinal muscle group, thereby reducing trauma, postoperative residual low back pain, operation time, bleeding, and frequency of fluoroscopy. Thus, OLIF+AF is a feasible treatment method for single-segment mild degenerative lumbar diseases.

Endo-TLIF versus MIS-TLIF in 1-segment lumbar spondylolisthesis: A prospective randomized pilot study.

OBJECTIVE: To evaluate the curative efficacy by comparing perioperative characteristics and 1.5-year observational outcomes in 1-segment lumbar spondylolisthesis between traditional minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and optimized Endoscopic TLIF techniques. METHODS: The study was a single-center, randomized controlled trial comparing two different treatment approaches for 1-segment lumbar spondylolisthesis. 102 patients treated by MIS-TLIF (48 cases) or Endo-TLIF (54 cases) were included from March 2018 to April 2019. Perioperative parameters and clinical outcomes were evaluated. Degree of slip were measured, and fusion rates were determined at 18 months after surgery. RESULTS: The Endo-TLIF group had similar return to work time and rate. Blood loss, left bed time, analgesic ratio were significantly less in Endo-TLIF group. The Endo-TLIF group had a significantly longer operative time. Significant postoperative reduction in %slip was showed in both groups. The VAS and ODI improved significantly in both groups after surgery. Significant decreases in low-back pain in Endo-TLIF group were found at postoperative day 1 and 3 months. The fusion rate in the two groups was similar. CONCLUSION: Endo-TLIF surgery with a C-shaped working tube and a visualization system may be regarded as an efficient alternative surgery for 1-segment lumbar spondylolisthesis. It is a safe and minimally invasive way to perform this surgery and has shown satisfactory clinical outcomes. TRIAL REGISTRATION: ChiCTR1800015197, 13 March 2018. TRIAL REGISTRY: Chinese Clinical Trial Registry. Registered 13 March 2018. http://www.chictr.org.cn/showproj.aspx?proj=25865.

Retrospective Comparative Study of Pedicle Screw Fixation via Quadrant Retractor and Buck's Technique in the Treatment of Adolescent Spondylolysis.

OBJECTIVE: To compare the effectiveness and practicality of pedicle screw fixation via the Quadrant retractor and Buck's technique in the treatment of adolescent spondylolysis. METHODS: A total of 31 patients who underwent pedicle screw fixation or Buck's technique at our hospital from 2012 to 2017 were selected for this retrospective study. The patients were divided into a pedicle screw group (16 patients) and a Buck's technique group (15 patients) according to surgical procedure. Age, sex, disease duration, involved segments, preoperative Oswestry disability index (ODI) scores, visual analogue scale (VAS) scores for low back pain (LBP), intraoperative blood loss, incision length, operative time and length of hospital stay were documented. ODI scores, VAS scores for LBP and fusion rates at 1 month, 6 months, 1 year and 3 years postoperatively were used to evaluate surgical outcomes. RESULTS: The average follow-up period was 32.75 ± 11.99 months in the pedicle screw group and 31.02 ± 9.64 months in the Buck's technique group. No significant differences in demographic data and perioperative data were found between the two groups (P > 0.05). The ODI scores and VAS scores for LBP in both groups were significantly improved at 3 years postoperatively compared with the values before surgery (ODI%: 45.74 ± 2.47 vs 10.99 ± 3.00; 45.29 ± 6.94 vs 15.73 ± 6.89. VAS: 5.94 ± 0.68 vs 1.50 ± 0.52; 6.13 ± 0.74 vs 2.13 ± 0.92, P < 0.05). The ODI scores of the patients in the pedicle screw group at 1 month to 3 years postoperatively were lower than those of the patients in the Buck's technique group (P < 0.05). Moreover, the VAS scores for LBP of the patients in the pedicle screw group at 6 months and 3 years postoperatively were lower than those of the patients in the Buck's technique group (P < 0.05). No significant difference in the VAS scores for LBP was found between the two groups at 1 month postoperatively (3.88 ± 0.50 vs 4.20 ± 0.56, P = 0.10). Three years postoperatively, good fusion of the pars interarticularis was achieved in all patients in the pedicle screw group, but four patients in the Buck's technique group did not achieve good fusion (P = 0.02). CONCLUSION: Both pedicle screw fixation and Buck's technique can achieve good outcomes in the treatment of adolescent spondylolysis. Pedicle screw fixation via the Quadrant retractor for the treatment of spondylolysis is associated with more satisfactory effects in terms of LBP relief and fusion results.

Outcomes of anterior vs. posterior approach to single-level lumbar spinal fusion with interbody device: An analysis of the nationwide inpatient sample.

BACKGROUND: Interbody devices have revolutionized lumbar spinal fusion surgery by improving mechanical stability and maximizing fusion potential. Several approaches for interbody fusion exist with two of the most common being anterior lumbar interbody fusion (ALIF) and posterior lumbar interbody fusion (PLIF). This study aims to compare patient data, hospital outcomes, and post-operative complications between an anterior vs. posterior approach to lumbar interbody fusion. METHODS: This retrospective cohort study utilized the Nationwide Inpatient Sample (NIS) and International Classification of Diseases, 10th edition (ICD10) codes to identify patients (18 +) from 2016 to 2018 who underwent lumbar interbody fusion under an anterior or posterior approach. Patients missing identifiers were excluded from this study. Patients were further investigated by demographic data and the presence of comorbidities. Hospital outcome data was investigated by length of stay (LOS), total hospital charges, mortality, and post-operative complications. RESULTS: 373,585 patients were included in this study. 257,975 (69%) underwent fusion via a posterior approach, and 115,610 (31%) via an anterior approach. Patients undergoing posterior approach were found to have a greater number of comorbidities than anterior (3.5 vs. 2, respectively, p = <0.001). The posterior approach was associated with decreased LOS (3.59 vs 4.19 days, p = <0.0001) and decreased total hospital charges ($141,700 vs $211,015, p = <0.0001). A posterior approach was found to have lower rates of post-operative complications. For the anterior approach cohort, tobacco dependence (OR=1.31 [1.20-1.42, p = <0.001], diabetes (OR=2.41 [2.33-2.49, p = <0.001], and osteoporosis (OR=1.42 [1.30-1.54, p = <0.001] were found to be significant independent predictors of post-operative pseudoarthrosis. Obesity (OR=1.28 [1.14-1.42, p = <0.001], tobacco dependence (OR=1.48 [1.40-1.56, p = <0.001], diabetes (OR=2.21 [2.10-2.32, p = <0.001], congestive heart failure (OR=1.20 [1.01-1.39, p = 0.04], and osteoporosis (OR=1.65 [1.55-1.75, p = <0.001], were found to be independent predictors of post-operative pseudoarthrosis in the posterior cohort. CONCLUSIONS: Patients who underwent the anterior approach suffered from increased hospital charges, length of stay, and increased risk of post-operative complications including mortality, wound dehiscence, hematoma/seroma, and pseudoarthrosis. Comorbid disease plays a significant role in the outcome of successful fusion with variable effect depending on the surgical approach. Increasing due diligence in patient selection should be considered when choosing an approach in pre-operative planning.

Risk Factors for Dysphagia after Anterior Cervical Discectomy and Fusion with the Zero-P implant system: A Study with Minimum of 2 Years Follow-up.

OBJECTIVE: To evaluate the risk factors for dysphagia after anterior cervical discectomy and fusion (ACDF) with the Zero-P Implant System by multidimensional analysis and investigated the predictive values of these risk factors for dysphagia. METHODS: A retrospective analysis of 260 patients who underwent ACDF with the Zero-P Implant System and had at least 2 year of follow-up were performed. All patients were divided into a non-dysphagia group and a dysphagia group. Sex, age, body mass index (BMI), intraoperative time, estimated blood loss, diabetes mellitus, hypertension, smoking, alcohol consumption, prevertebral soft-tissue thickness, the levels of surgery, O-C2 angle, C2-7 angle, T1 slope and segmental angle were analyzed. The Modified Japanese Orthopaedic Association (JOA) scoring system was used to determine functional status. NDI was used to evaluate neck pain and disability. The Bazaz grading system was chosen to evaluate dysphagia after surgery. Postoperative cerebrospinal fluid (CSF) leakage, infection, and dysphagia were recorded in both groups. An independent t-test was used to compare quantitative variables, a chi-square test was used to compare qualitative data between the two groups. To eliminate the influence of confounding factors, logistic regression was performed for multifactor regression of factors. The results were regarded as significant when the P-values were less than 0.05 in this study. RESULTS: In total, the non-dysphagia group comprised 70 patients and the dysphagia group comprised 190 patients, with an average age of 58.33 ± 4.68 years (ranging, 42-82 years). These patients were followed up for 28.5 ± 3.5 months (range, 24-32 months). For clinical outcomes, both groups demonstrated significant improvement in the NDI and JOA scores (P < 0.001). According to the Bazaz dysphagia grading system, mild, moderate, and severe dysphagia were found in 50, 17, and 3 patients, respectively. In total, 37.1% (n = 26) had resolved by 3 month, 38.6% (n = 27) by 6 months, and 17.1% (n = 12) by 12 months. Chi-square test results indicated that number of operated levels, operation time dT1 slope, dO-C2 angle, dC2-7 angle, segmental angle and dPSTT were associated with a high incidence of dysphagia. Multivariate logistic regression analysis showed that number of operated levels, operation time, dC2-7 angle and dPSTT were significantly associated with postoperative dysphagia. CONCLUSIONS: More operated levels, more operation time, more dC2-7 angle and dPSTT were the risk factors for postoperative dysphagia. In additional, sufficient preoperative preparation, evaluation combined with proficient and precise surgical treatment were suggested to reduce the incidence of postoperative dysphagia when ACDF was performed.

Bilateral open sacroiliac joint fusion during adult spinal deformity surgery using triangular titanium implants: technique description and presentation of 21 cases.

OBJECTIVE: Pelvic fixation enhances long constructs during deformity surgery. Subsequent loosening of iliac screws and pain at the pelvis occur in as many as 29% of patients. Concomitant sacroiliac (SI) fusion may prevent potential pain and failure. The objective of this study was to describe a novel surgical technique and a single institution's experience using bilateral SI fusion during adult deformity surgery with S2-alar-iliac (S2AI) screws and triangular titanium rods (TTRs) placed with navigation. METHODS: The authors reviewed open SI joint fusions with TTR performed between August 2019 and March 2020. All patients underwent lumbosacral fusion through a midline approach and bilateral S2AI pelvic fixation in the caudal teardrop, followed by TTR placement just proximal and cephalad to the S2AI screws using intraoperative CT imaging guidance. RESULTS: Twenty-one patients were identified who received 42 TTRs, ranging in size from 7.0 × 65 mm to 7.0 × 90 mm. Three TTRs (7%) were malpositioned intraoperatively, and each was successfully repositioned during index surgery without negative sequelae. All breaches occurred in a medial and cephalad direction into the pelvis. Incremental operative time for adding TTR averaged 8 minutes and 33 seconds per implant. CONCLUSIONS: Image-guided open SI joint fusion with TTR during lumbosacral fusion is technically feasible. The bony corridor for implant placement is narrower cephalad, and implants tend to deviate medially into the pelvis. Detection of malpositioned implant is aided with intraoperative CT, but this can be salvaged. A prospective randomized clinical trial is underway that will better inform the impact of this technique on patient outcomes.

Freehand screw insertion technique without image guidance for the cortical bone trajectory screw in posterior lumbar interbody fusion: what affects screw misplacement?

OBJECTIVE: Cortical bone trajectory (CBT) screw insertion using a freehand technique is considered less feasible than guided techniques, due to the lack of readily identifiable visual landmarks. However, in posterior lumbar interbody fusion (PLIF), after resection of the posterior anatomy, the pedicles themselves, into which implantation is performed, are palpable from the spinal canal and neural foramen. With the help of pedicle wall probing, the authors have placed CBT screws using a freehand technique without image guidance in PLIF. This technique has advantages of no radiation exposure and no requirement for expensive devices, but the disadvantage of reduced accuracy in screw placement. To address the problem of symptomatic breaches with this freehand technique, variables related to unacceptable screw positioning and need for revisions were investigated. METHODS: From 2014 to 2020, 182 of 426 patients with single-level PLIF were enrolled according to the combined criteria of L4-5 level, excluding cases of revision and isthmic spondylolisthesis; using screws 5.5 mm in diameter; and operated by right-handed surgeons. We studied the number of misplaced screws found and replaced during initial surgeries. Using multiplanar reconstruction CT postoperatively, 692 screw positions on images were classified using previously reported grading criteria. Details of pedicle breaches requiring revisions were studied. We conducted a statistical analysis of the relationship between unacceptable (perforations > 2 mm) misplacements and four variables: level, laterality, spinal deformity, and experiences of surgeons. RESULTS: Three screws in L4 and another in L5 were revised during initial surgeries. The total rate of unacceptable screws on CT examinations was 3.3%. Three screws in L4 and another in L5 breached inferomedial pedicle walls in grade 3 and required revisions. The revision rate was 2.2%. The percentage of unacceptable screws was 5.2% in L4 and 1.7% in L5 (p < 0.05), whereas other variables showed no significant differences. CONCLUSIONS: A freehand technique can be feasible for CBT screw insertion in PLIF, balancing the risks of 3.3% unacceptable misplacements and 2.2% revisions with the benefits of no radiation exposure and no need for expensive devices. Pedicle palpation in L4 is the key to safety, even though it requires deeper and more difficult probing. In the initial surgeries and revisions, 75% of revised screws were observed in L4, and unacceptable screw positions were more likely to be found in L4 than in L5.

Impact of an intraoperative coronal spinal alignment measurement technique using a navigational tool for a 3D spinal rod bending system in adult spinal deformity cases.

OBJECTIVE: In corrective spinal surgery for adult spinal deformity (ASD), the focus has been on achieving optimal spinopelvic alignment. However, the correction of coronal spinal alignment is equally important. The conventional intraoperative measurement methods currently used for coronal alignment are not ideal. Here, the authors have developed a new intraoperative coronal alignment measurement technique using a navigational tool for a 3D spinal rod bending system (CAMNBS). The purpose of this study was to test the feasibility of using the CAMNBS for coronal spinal alignment and to evaluate its usefulness in corrective spinal surgery for ASD. METHODS: In this retrospective cohort study, patients with degenerative lumbar kyphoscoliosis, a Cobb angle ≥ 20°, and lumbar lordosis ≤ 20° who had undergone corrective surgery (n = 67) were included. The pelvic teardrops on both sides, the S1 spinous process, the central point of the apex, a point on the 30-mm cranial (or caudal) side of the apex, and the central point of the upper instrumented vertebra (UIV) and C7 vertebra were registered using the CAMNBS. The positional information of all registered points was displayed as 2D figures on a monitor. Deviation of the UIV plumb line from the central sacral vertical line (UIV-CSVL) and deviation of the C7 plumb line from the CSVL (C7-CSVL) were measured using the 2D figures. Nineteen patients evaluated using the CAMNBS (BS group) were compared with 48 patients evaluated using conventional intraoperative radiography (XR group). The UIV-CSVL measured intraoperatively using the CAMNBS was compared with that measured using postoperative radiography. The prevalence of postoperative coronal malalignment (CM) and the absolute value of postoperative C7-CSVL were compared between the groups on radiographs obtained in the standing position within 4 weeks after surgery. Postoperative CM was defined as the absolute value of C7-CSVL ≥ 30 mm. Further, the measurement time and amount of radiation exposure were measured. RESULTS: No significant differences in demographic, sagittal, and coronal parameters were observed between the two groups. UIV-CSVL was 2.3 ± 9.5 mm with the CAMNBS and 1.8 ± 16.6 mm with the radiographs, showing no significant difference between the two methods (p = 0.92). The prevalence of CM was 2/19 (10.5%) in the BS group and 18/48 (37.5%) in the XR group, and absolute values of C7-CSVL were 15.2 ± 13.1 mm in the BS group and 25.0 ± 18.0 mm in the XR group, showing statistically significant differences in both comparisons (p = 0.04 and 0.03, respectively). The CAMNBS method required 3.5 ± 0.9 minutes, while the conventional radiograph method required 13.3 ± 1.5 minutes; radiation exposure was 2.1 ± 1.1 mGy in the BS group and 2.9 ± 0.6 mGy in the XR group. Statistically significant differences were demonstrated in both comparisons (p = 0.0002 and 0.03, respectively). CONCLUSIONS: From this study, it was evident that the CAMNBS did not increase postoperative CM compared with that seen using the conventional radiographic method, and hence can be used in clinical practice.

Acute failure of S2-alar-iliac screw pelvic fixation in adult spinal deformity: novel failure mechanism, case series, and review of the literature.

OBJECTIVE: Pelvic fixation with S2-alar-iliac (S2AI) screws is an established technique in adult deformity surgery. The authors' objective was to report the incidence and risk factors for an underreported acute failure mechanism of S2AI screws. METHODS: The authors retrospectively reviewed a consecutive series of ambulatory adults with fusions extending 3 or more levels, and which included S2AI screws. Acute failure of S2AI screws was defined as occurring within 6 months of the index surgery and requiring surgical revision. RESULTS: Failure occurred in 6 of 125 patients (5%) and consisted of either slippage of the rods or displacement of the set screws from the S2AI tulip head, with resultant kyphotic fracture. All failures occurred within 6 weeks postoperatively. Revision with a minimum of 4 rods connecting to 4 pelvic fixation points was successful. Two of 3 (66%) patients whose revision had less fixation sustained a second failure. Patients who experienced failure were younger (56.5 years vs 65 years, p = 0.03). The magnitude of surgical correction was higher in the failure cohort (number of levels fused, change in lumbar lordosis, change in T1-pelvic angle, and change in coronal C7 vertical axis, each p < 0.05). In the multivariate analysis, younger patient age and change in lumbar lordosis were independently associated with increased failure risk (p < 0.05 for each). There was a trend toward the presence of a transitional S1-2 disc being a risk factor (OR 8.8, 95% CI 0.93-82.6). Failure incidence was the same across implant manufacturers (p = 0.3). CONCLUSIONS: All failures involved large-magnitude correction and resulted from stresses that exceeded the failure loads of the set plugs in the S2AI tulip, with resultant rod displacement and kyphotic fractures. Patients with large corrections may benefit from 4 total S2AI screws at the time of the index surgery, particularly if a transitional segment is present. Salvage with a minimum of 4 rods and 4 pelvic fixation points can be successful.