Severe thoracic ossification of the ligamentum flavum often leads to thoracic spinal canal stenosis and spinal cord injury, which generates severe symptoms. Generally, patients still require surgery and aggravated spinal cord function impairment is a common complication. We propose a novel surgical technique to remove the ossified ligamentum flavum with the adhesive dura as a floating island. The purpose of this study was to evaluate the clinical efficacy and safety of floating island in the treatment of severe ossification of ligamentum flavum. A total of 31 patients with thoracic spinal stenosis and myelopathy caused by thoracic ossification of the ligamentum flavum from January 2019 to April 2022 were included in the study and were followed up at 1, 3, 6, and 12 months, respectively. All patients were treated with floating island laminectomy technique. Neurological function was assessed by the modified Japanese Orthopaedic Association (mJOA) scoring system before and after operation and the rate of improvement was calculated. Perioperative complications were also recorded in this study. All 31 patients were successfully managed by the same professional surgery team. The average operative time was 207.74 ± 58.54 min, the average hospital stay duration was 6.8 ± 1.27 days and the average intra-operative blood loss was 406.45 ± 217.85 ml. The average mJOA score at 1 month, 3 months, 6 months and 12 months after surgery increased from 4.68 ± 0.60 to 6.71 ± 0.73, 7.35 ± 0.76, 8.45 ± 0.85 and 9.06 ± 0.81, respectively. The average mJOA score after surgery was significantly higher than before (P < 0.001). The average recovery rate was (32.41 ± 8.55)

Objective:To explore short-term effectiveness of floating island laminectomy surgery in treating thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum. Methods:A total of 31 patients with thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum between January 2019 and April 2022 were managed with floating island laminectomy surgery. The patients comprised 17 males and 14 females, aged between 36 and 78 years, with an average of 55.9 years. The duration of symptoms of spinal cord compression ranged from 3 to 62 months (mean, 27.2 months). The lesions affected T 1-6 in 4 cases and T 7-12 in 27 cases. The preoperative neurological function score from the modified Japanese Orthopaedic Association (mJOA) was 4.7±0.6. Surgical duration, intraoperative blood loss, and complications were recorded. The thoracic MRI was conducted to reassess the degree of spinal cord compression and decompression after operation. The mJOA score was employed to evaluate the neurological function and calculate the recovery rate at 12 months after operation. Results:The surgical duration ranged from 122 to 325 minutes, with an average of 204.5 minutes. The intraoperative blood loss ranged from 150 to 800 mL (mean, 404.8 mL). All incisions healed by first intention after operation. All patients were followed up 12-14 months, with an average of 12.5 months. The patients' symptoms, including lower limb weakness, gait disorders, and pain, significantly improved. The mJOA scores after operation significantly increased when compared with preoperative scores ( P<0.05), gradually improving with time, with significant differences observed among 1, 3, and 6 months ( P<0.05). The recovery rate at 12 months was 69.76%±11.38%, with 10 cases exhibiting excellent neurological function and 21 cases showing good. During the procedure, there were 3 cases of dural tear and 1 case of dural defect. Postoperatively, there were 2 cases of cerebrospinal fluid leakage. No aggravated nerve damage, recurrence of ligamentum flavum ossification, or postoperative thoracic deformity occurred. Conclusion:The floating island laminectomy surgery is safe for treating thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum, effectively preventing the exacerbation of neurological symptoms. Early improvement and recovery of neurological function are achieved.

Objective:To investigate the short-term effectiveness of the anterior and middle columns in thoracolumbar tuberculosis reconstructed with whole autogenous spinous process-laminar bone through posterior approach. Methods:The retrospective study included 78 patients with thoracolumbar tuberculosis who underwent posterior approach surgery and anterior and middle column bone graft reconstruction between January 2012 and May 2023. Based on the type of autogenous bone graft used, patients were divided into group A (whole autogenous spinous process-laminar bone graft, 38 cases) and group B (autogenous structural iliac bone graft, 40 cases). There was no significant difference of baseline data, such as age, gender, disease duration, involved segment of spinal tuberculosis, and preoperative erythrocyte sedimentation rate (ESR), C reactive protein (CRP), Oswestry disability index (ODI), visual analogue scale (VAS) score, the American Spinal Injury Association (ASIA) grade, segmental kyphotic angle, and intervertebral height between the two groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stays, ESR, CRP, VAS score, ODI, bone fusion time, ASIA grade for neurological status valuation, postoperative complications, change of segmental kyphotic angle, change of intervertebral height were recorded and compared between the two groups. Results:The operation time in group A was significantly shorter than that in group B ( P<0.05); there was no significant difference in intraoperative blood loss, postoperative drainage, and hospital stays between the two groups ( P>0.05). All patients in the two groups were followed up 14-110 months (mean, 64.1 months); there was no significant difference in the follow-up time between the two groups ( P>0.05). The ESR, CRP, ODI, and VAS score at each time point after operation in both groups significantly improved when compared with those before operation, and further improved with the extension of time, the differences were significant ( P<0.05). There was no significant difference between the two groups ( P>0.05) except that the VAS score of group A was significantly better than that of group B at 3 days after operation ( P<0.05). There was no significant difference in fusion time between the two groups ( P>0.05). The neurological function of most patients improved after operation, and there was no significant difference in ASIA grade between the two groups at last follow-up ( P>0.05). There was no significant difference in segmental kyphosis angle and intervertebral height between the two groups at each time point ( P>0.05), and no significant difference in segmental kyphosis angle, intervertebral height correction and loss were found between the two groups ( P>0.05). In group A, there was 1 case of incision fat liquefaction and 1 case of incision infection; in group B, there was 1 case of deep venous thrombosis, 2 cases of pleural effusion, and 10 cases of pain in bone harvesting area; in both groups, there were 2 cases of gout caused by hyperuricemia. There was a significant difference in the incidence of pain in bone harvesting area between the two groups ( P<0.05), and there was no significant difference in the incidence of other complications between the two groups ( P>0.05). Conclusion:Whole autogenous spinous process-laminar bone grafting is equivalent to structural iliac bone graft in reconstruction of the anterior and middle columns in thoracolumbar tuberculosis through posterior approach, effectively supporting the stability of the anterior and middle columns of the spine, while resulting in shorter operation time and less postoperative pain in bone harvesting area.

ObjectivesCervical alignment and range of motion (ROM) changes after cervical spine surgery are related to cervical biomechanical and functions. Few studies compared these parameters between posterior laminoplasty and anterior 3‐level hybrid surgery incorporating anterior cervical discectomy and fusion (ACDF) with cervical disc replacement (CDR). This study is aimed to detect the differences of cervical alignment and ROM changes of the two surgeries in a matched‐cohort study.MethodsFrom January 2018 and May 2020, 51 patients who underwent 3‐level hybrid surgery incorporating ACDF with ACDR were included. A 1:1 match of the patients who underwent cervical laminoplasty based on age, gender, duration of symptoms, body mass index, and cervical alignment type was utilized as control group. General data (operative time, blood loss, etc.), Japanese Orthopaedic Association (JOA) score, VAS (Visual Analog Score), NDI (The Neck Disability Index), cervical sagittal alignment, and cervical range of motion (ROM) were recorded and compared.ResultsBoth groups gained significant improvement in JOA, VAS, NDI scores postoperatively (p < 0.05). Cervical alignment significantly increased in hybrid group and decreased in control group after surgeries (p < 0.001). ROM decrease was similar in two groups. For cervical lordosis, though cervical alignment angle in control group decreased, the final follow‐up cervical alignment and cervical alignment changes were not significantly different between hybrid and control groups. For cervical non‐lordosis, cervical alignment decreased in control group while increased in hybrid group. At final follow‐up, cervical alignment and the changes between the two groups were significantly different. Both control group and hybrid group had similar ROM decrease after the surgery no matter whether there was cervical lordosis or non‐lordosis. Hybrid surgery showed cervical alignments significantly improved and similar ROM preservation compared with control group at final follow‐up both for 1‐level and 2‐level disc replacement subgroups.ConclusionsThe hybrid surgery demonstrated advantages of preserving cervical alignment and gaining similar cervical ROM preservation compared with cervical laminoplasty, especially for cervical non‐lordosis. Given the importance of restoring lordotic cervical alignment, hybrid surgery may be preferred over laminoplasty to treat multilevel cervical disc herniation.

Bone tuberculosis, an extrapulmonary manifestation of tuberculosis, presents unique treatment challenges, including its insidious onset and complex pathology. While advancements in anti-tubercular therapy have been made, the efficacy is often limited by difficulties in achieving targeted drug concentrations and avoiding systemic toxicity. The intricate bone structure and presence of granulomas further impede effective drug delivery. Nano-drug delivery systems have emerged as a promising alternative, offering the enhanced targeting of anti-tubercular drugs. These systems, characterized by their minute size and adaptable surface properties, can be tailored to improve drug solubility, stability, and bioavailability, while also responding to specific stimuli within the bone TB microenvironment for controlled drug release. Nano-drug delivery systems can encapsulate drugs for precise delivery to the infection site. A significant innovation is their integration with prosthetics or biomaterials, which aids in both drug delivery and bone reconstruction, addressing the infection and its osteological consequences. This review provides a comprehensive overview of the pathophysiology of bone tuberculosis and its current treatments, emphasizing their limitations. It then delves into the advancements in nano-drug delivery systems, discussing their design, functionality, and role in bone TB therapy. The review assesses their potential in preclinical research, particularly in targeted drug delivery, treatment efficacy, and a reduction of side effects. Finally, it highlights the transformative promise of nanotechnology in bone TB treatments and suggests future research directions in this evolving field.

Study Design Retrospective case-control study. Objectives To evaluate postoperative outcomes of single-level cervical disc arthroplasty (CDA) in patients with osteopenia and compare these results with a matched cohort of normal bone mineral density (BMD). Methods Patients who had undergone single-level CDA were collected and screened. Included patients were divided into the osteopenia group and the normal group. 38 eligible patients with osteopenia were included in the final analysis. Subsequently, a 1:1 match was utilized. Clinical, radiographic data, and complications were recorded. Appropriate statistical methods were applied to conduct analysis using SPSS version 24.0. Results The mean follow-up time was 30.5 ± 27.3 months. The osteopenia group achieved satisfactory clinical outcomes, with no significant intergroup differences. Additionally, there were no significant differences between groups in any of the radiological parameters, either in cervical alignment or segmental height, or range of motion. The radiological incidence rate of adjacent segmental degeneration and heterotopic ossification (HO) was comparable in both groups, respectively, with a similar composition of ROM-limiting HO. However, the osteopenia group had a tendency of more implant subsidence (2.7% vs 15.2%). The logistic regression analysis showed the osteopenia group had a significantly higher incidence rate of anterior bone loss (ABL) (OR = 5.37, 95% CI: 1.50 - 19.22). Conclusions Single-level CDA for patients with osteopenia achieved similar satisfactory clinical outcomes compared with the normal BMD group. Meanwhile, the osteopenia group maintained adequate sagittal balance and segmental height. Based on this observation, this option may be feasible for selected patients with osteopenia.

To compare clinical and radiological outcomes of multi-fold rib and structural iliac bone grafts, the primary autologous graft techniques in anterolateral-only surgery for single-segment thoracic and thoracolumbar spinal tuberculosis. This retrospective study included 99 patients treated from January 2014 to March 2022, categorized into 64 with multi-fold rib grafts (group A) and 35 with structural iliac bone grafts (group B). Outcomes assessed included hospital stay, operation time, intraoperative blood loss, postoperative drainage, complications, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the Visual Analog Scale (VAS) for pain, the Oswestry Disability Index (ODI), bone fusion time, and the American Spinal Injury Association (ASIA) impairment scale grade. Segmental kyphotic angle and intervertebral height were measured radiologically before surgery and follow-up. The mean follow-up was 63.50 ± 26.05 months for group A and 64.97 ± 26.43 months for group B (P > 0.05). All patients had achieved a clinical cure. Group A had a shorter operation time (P = 0.004). Within one week post-surgery, group B reported higher VAS scores (P < 0.0001). Neurological performance and quality of life significantly improved in both groups. No significant differences were observed in segmental kyphotic angle and intervertebral height between the groups pre- and postoperatively (P > 0.05). However, group A showed a greater segmental kyphotic angle at the final follow-up, while group B had better maintenance of kyphotic angle correction and intervertebral height (P < 0.05). Bone fusion was achieved in all patients without differences in fusion time (P > 0.05). Multi-fold rib grafts resulted in shorter operation times and less postoperative pain, while structural iliac bone grafts provided better long-term maintenance of spinal alignment and stability, suggesting their use in cases where long-term outcomes are critical.

ObjectiveThis retrospective monocentric study was conducted to evaluate the clinical and radiological outcomes of the nano-hydroxyapatite/polyamide66 (n-HA/PA66) cage in reconstructing the anterior column of the spine following total en bloc spondylectomy (TES).MethodsA cohort of 24 patients, 20 diagnosed with primary malignant tumors and 4 with metastatic malignancies, was selected based on specific inclusion criteria. All were subjected to TES and anterior column reconstruction with the n-HA/PA66 cage from January 2013 to July 2023 at a single institution. Pre-operative embolization was performed on all patients. Documented factors included operation duration, intraoperative blood loss, length of hospital stay, treatment history, and involved level. Mechanical complications and radiological parameters such as the local kyphotic angle (LKA), anterior vertebral height (AVH), posterior vertebral height (PVH), cage subsidence, and bone fusion time were evaluated. Quality of life and neurological function were gauged using tools like the Visual Analog Scale (VAS), Eastern Cooperative Oncology Group (ECOG) performance score, Karnofsky Performance Score (KPS) scale, and American Spinal Injury Association (ASIA) grading.ResultsAll patients were followed up for 12–127 months, with an average period of 39.71 months. An average operation time of approximately 8.57 h and a blood loss volume of about 1,384 ml were recorded. No instances of tumor recurrence or multiple organ metastases were reported, though recurrence was detected in 2 living patients. Solid fusion was achieved in all patients at a mean time of 6.76 ± 0.69 months. Cage breakage or migration was not observed. Subsidence into the adjacent vertebral bodies was identified in 3 patients but was deemed clinically irrelevant. Significant improvements in VAS, ECOG performance score, KPS scale, and ASIA scores were noted from pre- to post-surgery (P < 0.05). A marked enhancement in the AVH was observed from before surgery to immediately after (P < 0.05). LKA, AVH, and PVH values between postoperative and final follow-up showed no significant variance (P > 0.05).ConclusionThe integration of TES and the n-HA/PA66 cage was found to yield promising clinical and radiological outcomes in anterior column spine reconstruction. The use of this material did not hinder oncological care, including the provision of adjuvant treatments (chemo/radiotherapy), ultimately contributing to the enhanced long-term quality of life for spinal tumor patients.

Objective To investigate whether bone mineral density (BMD) measured in Hounsfield units (HUs) correlates with titanium mesh cage (TMC) subsidence after anterior cervical corpectomy and fusion (ACCF). Methods A total of 64 patients who underwent one or two levels of ACCF with TMC with a mean follow-up of 19.34 ± 7.86 months were analysed. HU values were measured three times in 3 different planes in the upper and lower vertebrae according to published methods. Subsidence was defined as segmental height loss of more than 3 mm. Pearson correlation analysis was performed. Receiver operating characteristic (ROC) curve analysis was used to obtain optimal thresholds. A multivariate logistic regression analysis was also conducted. Results Twenty-two patients (34.38%) had evidence of TMC subsidence on follow-up x-ray. The mean HU values in the subsidence group (317.34 ± 32.32, n = 22) were significantly lower than those in the nonsubsidence group (363.07 ± 25.23 n = 42, p < 0.001, t test). At last follow-up, mean disc height loss was 4.80 ± 1.16 mm in the subsidence group and 1.85 ± 1.14 mm in the nonsubsidence group ( p < 0.001). There was a negative correlation between HU values and disc height loss (Pearson's coefficient −0.494, p < 0.001). HU values decreased gradually from the C3 vertebra to the C7 vertebra, and the HU values of the C5, C6, and C7 vertebrae in the nonsubsidence group were significantly higher than those in the subsidence group ( p < 0.05). Furthermore, there were significant differences between the groups in the segmental angle at the last follow-up and the mean changes in segmental angle ( p < 0.05). The area under the ROC curve was 0.859, and the most appropriate threshold of the HU value was 330.5 (sensitivity 100%, specificity 72.7%). The multivariate logistic regression analysis showed that older age ( p = 0.033, OR = 0.879), lower LIV HU value ( p < 0.001, OR = 1.053) and a greater segmental angle change ( p = 0.002, OR 6.442) were significantly associated with a higher incidence of TMC subsidence after ACCF. Conclusion There are strong correlations between a lower HU value and TMC subsidence after ACCF. More accurate assessment of bone quality may be obtained if HU measurement can be used as a routine preoperative screening method together with DXA. For patients with HU values <330.5, a more comprehensive and cautious preoperative plan should be implemented to reduce TMC subsidence.

OBJECTIVE: Due to the lack of an additional anterior plate, the motion stability of a zero-profile device with an anchored cage (AC) may be inferior to that of a traditional plate-cage construct (PCC). However, the impact of this difference in motion stability on various outcomes has not been fully explored. Therefore, the aim of this study was to compare the motion stabilization features of an AC and a PCC and analyze their impact on postoperative outcomes and complications. METHODS: A retrospective study of patients treated with single-level anterior cervical discectomy and fusion from January 2008 to May 2016 was performed. First, clinical and radiological outcomes, postoperative complications and time to achieve motion stabilization were compared between the AC and PCC groups. Then, based on the time to achieve motion stabilization, all patients were divided into group A (time to achieve motion stabilization <3 months), group B (time to achieve motion stabilization from 3-6 months), and group C (time to achieve motion stabilization >6 months). The early postoperative complications were compared across the 3 groups. Motion stabilization was measured on dynamic cervical radiographs using the interspinous process method and Cobb angle method according to previously published methods. RESULTS: A total of 160 patients met the inclusion criteria, including 90 patients in the AC group and 70 patients in the PCC group. There were no significant differences between the AC and PCC groups in the clinical outcomes, C2-7 angle change, segmental angle change, final fusion rate or adjacent-level degeneration (P > 0.05). The disc height loss was 226 +/- 1.00 mm in the AC group and 1.76 +/- 1.13 mm in the PCC group (P = 0.004), and the incidence of implant subsidence was 24.44% in the AC group and 11.43% in the PCC group (P = 0.036). In addition, the PCC was more dynamically stable than the AC at 3 months post-surgery (P < 0.001), and at this time, the disc height loss and implant subsidence in motion-stable patients were significantly lower than those in motion-unstable patients (P < 0.05). Furthermore, our results also showed that when the arrival time of motion stabilization was prolonged, the loss of disc height and occurrence of subsidence gradually increased. CONCLUSIONS: More attention should be given to minimizing the adverse impact of poor motion stability in the design and development of future zero-profile cervical implants, although this has little impact on clinical efficacy.

目的:分析颈前路减压Zero-P融合固定术后椎间隙高度(intervertebral height,IH)变化对临床疗效和影像学参数的影响.方法:收集2014年5月～2017年12月在我院行颈前路减压Zero-P融合固定术且随访时间1年以上的123例脊髓型和神经根型颈椎病患者的资料.记录术前、术后1周及末次随访时的手术节段IH,并按术后平均IH变化值(术后1周IH与末次随访的差值)将所有患者分为IH维持组(IH变化值＜平均IH变化值)和IH丢失组(IH变化值≥平均IH变化值).比较两组患者的性别、年龄、手术节段,术前、术后1周及末次随访时的日本骨科学会(Japanese Orthopedics Association,JOA)颈椎功能评分、颈痛视觉模拟评分(visual analogue score,VAS)、颈椎功能障碍指数(neck disability index,NDI)、C2-7 Cobb 角及手术节段曲度,术后 3周内的吞咽困难发生率,术后3个月、6个月及末次随访的融合率及末次随访时的邻近节段退变(adjacent segment degeneration,ASD)发生率.两组间定量变量的差异采用独立样本 t检验,定性变量差异进行卡方检验.结果:根据所有患者术后平均IH变化值(2.08±0.94mm),将123例患者分为2组,其中IH维持组64例,随访时间为15.95±3.39个月;IH丢失组59例,随访时间为16.95±2.87个月.两组的性别、年龄、手术节段及随访时间均无统计学差异(P＞0.05),术前、术后1周及末次随访时的JOA评分、VAS评分、NDI、C2-7 Cobb角和手术节段曲度两组间比较均无统计学差异(P＞0.05),吞咽困难发生率及末次随访时的融合率两组间比较均无统计学差异(P＞0.05).IH维持组术前IH为5.65土 1.69mm,术后1周为8.33土0.78mm,末次随访为6.89±0.98mm,平均变化量为1.44±0.79mm;IH丢失组术前IH为5.31 土 1.58mm,术后1周为8.25土0.76mm,末次随访为5.50±1.01mm,平均变化量为2.75±0.52mm.IH维持组末次随访时IH和IH变化值显著高于IH丢失组(P＜0.001).术后3个月时IH维持组融合率为64.06％,IH丢失组为42.37％(P=0.019);术后6个月时IH维持组融合率为81.25％,IH丢失组为54.24％(P=0.002).末次随访时IH维持组下邻近节段退变发生率为12.5％,显著低于IH丢失组的28.81％(P=0.027).IH维持组假体下沉发生率为3.13％,显著低于IH丢失组的13.56％(P--0.047).结论:颈前路减压Zero-P融合固定术后手术节段IH丢失发生率较高;若IH丢失≥2mm可能会降低术后早期融合率,并增加ASD及假体下沉等并发症的发生率.

BACKGROUND:Cervical disc arthroplasty (CDA) using Prestige LP disc has been widely used for cervical degenerative disease. Postoperative shell angle (SA) is the angle between the upper and lower prosthesis endplate and previous studies have reported a significant correlation between prosthesis SA with postoperative biomechanical stress. Due to the lack of reference range in SA, a larger discrepancy exists in postoperative SA among the patients after CDA with Prestige LP disc. METHODS:A total of 160 patients who had been subjected to single level CDA with Prestige-LP were enrolled. SA was defined the angle between the upper and lower prosthesis endplate and patients were assigned into parallel (SA 0°-3°) and lordotic (SA > 3°) groups according to the immediate postoperative SA. Patients were followed up for a mean duration of 27.78 ± 5.13 months. Clinical, radiographic and complication data were compared among groups. RESULTS:90 patients were assigned in the parallel group while 70 patients were included in the lordotic group. The mean immediate postoperative SA in the parallel and lordotic groups were 1.64 ± 0.08° and 4.88 ± 1.20°, respectively (p < 0.05). FSU angle in the parallel group at 1 year and last follow-up were 2.6 ± 2.1° and 2.1 ± 2.0°, respectively, with a change value of - 0.68 ± 2.28°. In the lordotic group, FSU angle at 1 year and last follow-up were 3.3 ± 2.5° and 3.1 ± 2.2°, respectively, with a change value of 0.70 ± 1.43°. At 1 year, the FSU angle in the parallel group was significantly low than in the lordotic group (p < 0.05). Besides, average intervertebral space heights (ISH) at 6 months, 1 year and last follow-up were 6.81 ± 0.38 mm, 6.79 ± 0.3 7 mm, 6.78 ± 0.36 mm in the parallel group and 6.64 ± 0.24 mm, 6.32 ± 0.19 mm, 6.30 ± 0.19 mm in the lordotic group, respectively (all p < 0.05). There were no significant differences in clinical outcomes and complications between the groups (p > 0.05). CONCLUSIONS:Immediate postoperative SA has no significant effects on clinical outcomes and complications after CDA with Prestige-LP. However, it has a positive correlation with postoperative FSU angle and a negative correlation with ISH maintenance.

OBJECTIVE:To explore the influence factors of anterior bone loss (ABL) after cervical disc arthroplasty (CDA) and effects of ABL on the clinical and radiographic outcomes. METHODS:One hundred and fifty-five patients who underwent single-level Prestige-LP CDA between January 2008 and December 2017 and met the inclusive criteria were enrolled in the study. Perioperative data of patients were collected. The Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), and the visual analogue scale (VAS) score were used for clinical outcomes evaluation. Radiographic parameters including cervical lordosis, C 2-7 range of motion (ROM), disc angle, segmental ROM, and the lengths of the upper and lower endplates were assessed on the X-ray films. Device-related complications, including ABL, subsidence, radiographic adjacent segment pathology, and heterotopic ossification, were recorded. Univariate analysis was used to analyze the related factors, and logistic regression analysis was used to screen the influence factors. Patients were grouped according to whether ABL occurred after operation, and the differences in clinical and imaging evaluation parameters were compared. RESULTS:There were 94 cases (60.6%) in the ABL group and 61 cases (39.4%) in the non-ABL group. Univariate analysis showed the significant differences in age, body mass index (BMI), and intraoperative blood loss between the two groups ( P<0.05). However, there was no significant difference in gender, bone mineral density (T value), preoperative blood calcium level, preoperative blood phosphorus level, preoperative alkaline phosphatase level, operative segment, operative time, and follow-up time between the two groups ( P>0.05). Multivariate analysis showed that the age and BMI were influence factors for ABL after CDA ( P<0.05). The JOA score, NDI, and VAS score significantly improved in both groups at 3 months after operation ( P<0.05), and the scores were further improved at last follow-up ( P<0.05). There was no significant difference in JOA score, NDI, and VAS score between the two groups before and after operation ( P>0.05). The preoperative cervical lordosis was significantly smaller in the ABL group than in the non-ABL group ( t=-2.402, P=0.018). At last follow-up, the segmental ROM was significantly greater in the ABL group than in the non-ABL group ( P<0.05), and the lengths of the upper and lower endplates were less in the ABL group than in the non-ABL group ( P<0.05). No significant difference in the other radiographic parameters between the two groups were found ( P>0.05). Prosthesis subsidence occurred in 5 cases (3.2%), including 3 cases in the ABL group and 2 cases in the non-ABL group; the difference between the two groups was not significant ( P=1.000). Heterotopic ossification occurred in 67 cases (43.2%), including 32 cases in the ABL group and 35 cases in the non-ABL group; the difference between the two groups was significant ( χ 2=8.208, P=0.004). High-grade heterotopic ossification was detected in 26 cases (13 cases in the ABL group and 13 cases in the non-ABL group). Twenty-nine cases (18.7%) had radiographic adjacent segment pathology, including 15 cases in the ABL group and 14 cases in non-ABL group; the difference between the two groups was not significant ( χ 2=1.190, P=0.276). CONCLUSION:The incidence of ABL after CDA was relatively high, which mainly occurred within 3 months after operation, and no longer progressing with stable radiographic features after the first 12 months. Age and BMI were independent influence factors for ABL. ABL does not affect the clinical outcomes but may preserve more ROM of prostheses.

Objective To investigate the effect of modified lateral mass screws implantation strategy on axial symptoms in cervical expansive open-door laminoplasty. Methods A clinical data of 166 patients, who underwent cervical expansive open-door laminoplasty between August 2011 and July 2016 and met the selection criteria, was retrospective analyzed. Among them, 81 patients were admitted before August 2014 using the traditional mini-plate placement and lateral mass screws implantation strategy (control group), and 85 patients were admitted after August 2014 using modified lateral mass screws implantation strategy (modified group). There was no significant difference in the gender composition, age, clinical diagnosis, disease duration, diseased segment, and preoperative Japanese Orthopaedic Association (JOA) score, pain visual analogue scale (VAS) score, Neck Disability Index (NDI), cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, and Pavlov's value between the two groups ( P>0.05). The operation time, intraoperative blood loss, the number of facet joints penetrated by lateral mass screws, effectiveness evaluation indexes (JOA score and improvement rate, VAS score, NDI), imaging evaluation indexes (cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, Pavlov's value, and lamina open angle), and complications were recorded and compared between the two groups. Results The modified group had shorter operation time and lower intraoperative blood loss than the control group ( P<0.05). There were 121 (29.9%, 121/405) and 10 (2.4%, 10/417) facet joints penetrated by lateral mass screws in control and modified groups, respectively; and the difference in incidence was significant ( χ 2=115.797, P=0.000). Eighteen patients in control group had 3 or more facet joints penetrated while no patients in modified group suffered 3 or more facet joint penetrated. The difference between the two groups was significant ( P=0.000). All patients were followed up, the follow-up time was (28.7±4.9) months in modified group and (42.4±10.7) months in control group, showing significant difference ( t=10.718, P=0.000). The JOA score, VAS score, and NDI at last follow-up of the two groups were significantly improved compared with preoperative ( P<0.05); there was no significant difference in JOA score and improvement rate and VAS score between the two groups ( P>0.05), but the NDI was significantly lower in modified group than in control group ( P<0.05). There were significant differences in cervical curvature and range of motion, spinal canal diameter, Pavlov's value, and cross-sectional areas at last follow-up when compared with those before operation in both groups ( P<0.05). There was no significant difference in the above indicators and lamina open angle between the two groups ( P>0.05). The modified group has a relative lower axial symptom rate (23/85, 27.1%) than the control group (27/81, 33.3%), but the difference was not significant ( Z=-1.446, P=0.148). There was no significant differences between the two groups in the incidences of C 5 nerve root palsy, cerebrospinal fluid leakage, wound infection, and lung or urinary tract infection ( P>0.05). Conclusion In the cervical expansive open-door laminoplasty, the modified lateral mass screws implantation strategy can effectively reduce the risk of lateral mass screw penetrated to the cervical facet joints, and thus has a positive significance in avoiding the axial symptoms caused by facet joint destruction.

Background Cervical disc replacement (CDR) has been widely used to treat one- and two-level cervical degenerative disc disease. Studies have shown the effectiveness of CDR in preserving range of motion (ROM) and delaying adjacent segment degeneration (ASD). Cervical sagittal alignment is an important factor affecting favorable clinical outcomes in cervical spine surgery. This study aimed to explore whether cervical sagittal alignment can be maintained after CDR and to identify the impact of cervical sagittal alignment on outcomes after CDR. Methods This was a single-center, retrospective study. 132 patients who underwent one-level CDR were included. Cervical sagittal alignments, including cervical lordosis (CL), segmental alignment (SA), sagittal vertical axis (SVA), T1 slope (T1s), and T1s minus CL (T1s-CL), were measured. The effects of cervical sagittal alignment on the CDR outcomes were analyzed. Patients were divided into the heterotopic ossification (HO) group and ASD group to determine the potential impacts of cervical sagittal parameters. Results The cervical sagittal alignment parameters, except for the SVA, were significantly improved after CDR and showed decreasing trends at the last follow-up. Significantly higher CL and T1s were found in patients with better ROM after CDR. SVA ≥ 20 mm increased the risk of anterior HO (odds ratio = 2.945, P = 0.007). Significantly kyphotic SA and lower T1s values were found in the ASD patients than in the non-ASD patients ( P < 0.05). Patients with ASD at the inferior level showed significantly worse CL ( P < 0.05). Conclusion CDR had limited function of improving cervical sagittal alignment. Poor cervical sagittal alignment after CDR was associated with HO, ASD, and less ROM.

-OBJECTIVE: To compare clinical and imaging outcomes after cervical disc replacement (CDR) in patients with different Hounsfield units (HU). -METHODS: We performed a retrospective study of patients with cervical degenerative disc disease treated by 1-level and 2-level Prestige-LP arthroplasty. The patients were divided into group A (HU <320), group B (HU 320-347), and group C (HU >347) according to the results of cervical vertebral HU measurement in the literature, and the clinical and radiographic results were compared among the 3 groups. -RESULTS: A total of 127 patients were reviewed, comprising 13 patients in group A, 31 patients in group B, and 83 patients in group C. The clinical parameters were significantly improved postoperatively in the 3 groups (P < 0.05). However, no significant differences were found among the 3 groups at the final follow-up (P > 0.05). The mean postoperative intervertebral space height (ISH) was 4.76 +/- 0.45 mm, 5.23 +/- 0.81 mm, and 6.26 +/- 1.12 mm in the 3 groups, respectively. The postoperative ISH in group C was significantly higher than those in the other groups at the final follow-up (P < 0.001). One patient in group A and 1 patient in group B had implant subsidence, and degeneration at the inferiorly adjacent level was radiographically identified in 30.77% patients in group A, 16.13% patients in group B, and 9.64% patients in group C. However, there were only significant differences between group A and group C in subsidence (P = 0.011) and occurrence of adjacent level degeneration (P = 0.032). -CONCLUSIONS: The HU value has a large variation range among the patients with T-score double dagger-2.5. We found significantly increased rates of implant subsidence, loss of ISH, and adjacent segment degeneration in patients with lower HU value undergoing CDR. However, these radiographic complications did not predispose patients with lower HU value to worse clinical outcomes. Routine application of HU combined with dual-energy X-ray absorptiometry measurement to evaluate bone quality may help to screen the optimal candidates for CDR and reduce the implant-related complications.

Background Biomechanical studies have demonstrated that uncovertebral joint contributes to segment mobility and stability to a certain extent. Simultaneously, osteophytes arising from the uncinate process are a common cause of cervical spondylotic radiculopathy (CSR). For such patients, partial uncinatectomy (UT) may be required. However, the clinical efficacy and sagittal alignment of partial UT during anterior cervical discectomy and fusion (ACDF) have not been fully elucidated. Methods A total of 87 patients who had undergone single level ACDF using a zero-profile device from July 2014 to December 2018 were included. Based on whether the foraminal part of the uncovertebral joint was resected or preserved, the patients were divided into the ACDF with UT group ( n = 37) and the ACDF without UT group ( n = 50). Perioperative data, radiographic parameters, clinical outcomes, and complications were compared between the two groups. Results The mean follow-up was 16.86 ± 5.63 and 18.36 ± 7.51 months in the ACDF with UT group and ACDF without UT group, respectively ( p > 0.05). The average preoperative VAS arm score was 5.89 ± 1.00 in the ACDF with UT group and 5.18 ± 1.21 in the ACDF without UT group ( p = 0.038). However, the average VAS arm score was 4.22 ± 0.64, 4.06 ± 1.13 and 1.68 ± 0.71, 1.60 ± 0.70 at 1 week post operation and at final follow up, respectively, ( p > 0.05). We also found that the C2-7 SVA and St-SVA at the last follow-up and their change (last follow-up value − preoperative value) in the ACDF with UT group were significantly higher than ACDF without UT group ( p < 0.05). No marked differences in the other cervical sagittal parameters, fusion rate or complications, including dysphagia, ASD, and subsidence, were observed. Conclusions Our result indicates that ACDF using a zero-p implant with or without partial UT both provide satisfactory clinical efficacy and acceptable safety. However, additional partial UT may has a negative effect on cervical sagittal alignment.

Introduction: The posterior ligamentous complex (PLC) offers restraints to deformation in a complex and interconnected manner. The stability and range of motion (ROM) of the posterior cervical spine is greatly restricted when the PLC is damaged, even without bone disruptions. We describe a novel surgical technique, its advantages, and the postoperative condition of the first patient to use artificial ligament in a reconstruction surgery of PLC injuries in patients without lower cervical vertebral fracture. This technique aimed to fully retain the mobility of the injured segment based on spinal stability and apply dynamic reconstruction in patients’ treatment. Method: We present a detailed description of the reconstruction surgery with artificial ligaments performed on C4-6 PLC injuries in a 27-year-old male presented with neck pain and restricted movement following a high fall injury accompanied by impaired movement of limbs. Results: Immediately postsurgery, the patient’s neck pain and quadriparesis had been improved. The spinal canal decompression and cervical spine sequence results were satisfactory, the facet joint face was in a good position, and the spinous process spacing returned to normal. After three months of rehabilitation, the patient reported improvement of symptoms and the physical and imaging examination showed a significant improvement in the patient’s condition. The patient’s neck mobility motor function had improved further. Conclusion: The present data demonstrate that the novel technique for reconstruction of PLC injury is feasible and safe. However, familiarity with cervical anatomy and adequate experience in lateral mass screws placement during surgery is crucial for this procedure. Therefore, a highly experienced cervical surgery team is recommended to perform the surgery.

Purpose: Cervical sagittal balance plays important roles in transmitting the load of the head and maintaining global spinal balance. This study aimed to identify the association of cervical sagittal alignment with adjacent segment degeneration (ASD) and heterotopic ossification (HO) after Prestige-LP cervical disc replacement (CDR). Methods: We enrolled 132 patients who underwent one-level Prestige-LP CDR with 2–10 years of follow-up. Cervical sagittal alignment parameters, including the degree of C2–C7 lordosis (CL), functional spinal unit angle (FSUA), sagittal vertical axis (SVA),, and T1 slope (T1s), were measured. ASD and HO were evaluated at the last follow-up. Unpaired t tests and logistic regression analysis were used to identify the associations of cervical sagittal alignment with ASD and HO. Results: We found that patients who developed ASD showed significantly lower FSUA (2.1° vs. −1.4°, p < 0.001) and T1s values (28.4° vs. 25.5°, p = 0.029) after surgery. Similarly, the postoperative CL was significantly better in patients without ASD or HO (18.0° vs. 14.4°, p = 0.043). The decrease in the T1s at the last follow-up was significantly larger in the patients with ASD (−11.0° vs. −3.2°, p = 0.003), HO (−6.7° vs. −2.7°, p = 0.050), and ASD or HO (−7.0° vs. −0.8°, p < 0.001) than in those without ASD or HO. Multivariate logistic regression analysis showed that both the FSUA and T1s are associated with ASD and that the degree of CL is associated with postoperative complications. Conclusion: The results imply that maintaining cervical sagittal alignment after Prestige-LP CDR is important.