Abstract
目的
探讨采用超声骨刀系统行椎板切除、后纵韧带骨化块切断联合去后凸内固定矫形术治疗多节段胸椎后纵韧带骨化症（thoracic ossification of posterior longitudinal ligament，T-OPLL）的安全性及临床疗效。
方法
回顾分析2020年1月—2023年4月采用超声骨刀系统行椎板切除、后纵韧带骨化块切断联合去后凸内固定矫形术治疗的8例多节段T-OPLL患者临床资料。男3例，女5例；年龄41～67岁，平均57.1岁。病程3～74个月，平均33.4个月。主要临床症状为进行性双下肢麻木无力、行走不稳，有胸背部疼痛者3例，大小便功能障碍者5例；7例表现为下肢肌张力增高、腱反射亢进、Babinski征阳性，1例为下肢肌力减弱、皮肤感觉减退、腱反射减弱、病理征阴性。8例均存在多节段胸椎后纵韧带骨化，骨化节段4～8节；5例合并多节段黄韧带骨化。术前日本骨科协会（JOA）胸脊髓功能评分为（4.3±0.9）分，疼痛视觉模拟评分（VAS）为（6.9±1.0）分，胸椎管狭窄节段后凸Cobb角为（34.62±10.76）°。记录手术时间、术中出血量及并发症发生情况。采用VAS评分评估患者腰背部疼痛，JOA评分评价胸脊髓功能并计算JOA改善率，测量狭窄节段后凸Cobb角并计算后凸Cobb角改善率。
结果
手术时间210～340 min，平均271.62 min；术中出血量900～2 100 mL，平均1 458.75 mL。切除椎板数4～8节，平均6.1节。3例术中出现硬膜撕裂及脑脊液漏，患者切口均Ⅰ期愈合。8例患者均获随访，随访时间12～26个月，平均18.3个月。无内固定物松动、断钉、断棒等并发症发生，骨化块未见明显进展。末次随访时，VAS评分为（1.4±0.7）分，JOA胸脊髓功能评分为（9.8±0.7）分，狭窄节段后凸Cobb角为（22.12±8.28）°，均较术前显著改善（t=11.887，P<0.001；t=13.015，P<0.001；t=7.395，P<0.001）。JOA改善率为81.06%±10.93%，其中优5例、良3例；后凸Cobb角改善率为36.51%±14.20%。
结论
采用超声骨刀系统行椎板切除、后纵韧带骨化块切断联合去后凸技术治疗多节段T-OPLL安全有效，操作较简单，是一种可行的方案。
Keywords: 胸椎后纵韧带骨化症, 椎管狭窄, 超声骨刀
Abstract
Objective
To explore the safety and effectiveness of multisegmental thoracic ossification of posterior longitudinal ligament (T-OPLL) treated by laminectomy, posterior longitudinal ligament ossification block release combined with dekyphosis orthopedic surgery using ultrasonic bone scalpel system.
Methods
The clinical data of 8 patients with multisegmental T-OPLL treated with laminectomy, posterior longitudinal ligament ossification block release combined with dekyphosis orthopedic surgery using ultrasonic bone scalpel system between January 2020 and April 2023 was retrospectively analyzed. There were 3 males and 5 females; the age ranged from 41 to 67 years, with a mean of 57.1 years. The disease duration ranged from 3 to 74 months, with a mean of 33.4 months. Symptoms were progressive numbness and weakness of both lower limbs, unsteady walking, chest and back pain in 3 cases, and urinary and bowel dysfunction in 5 cases; 7 cases showed increased muscle strength of the lower limbs, hyperreflexia of the tendons, and a positive Babinski sign, and 1 case showed decreased muscle strength of the lower limbs, decreased skin sensation, decreased knee and Achilles tendon reflexes, and a negative pathologic sign. Multisegmental posterior longitudinal ligament ossification of thoracic spine was found in 8 cases, with 4-8 segments of ossification, and in 5 cases with multisegmental ossification of the ligamentum flavum. The preoperative Japanese Orthopaedic Association (JOA) thoracic spinal function score was 4.3±0.9, the visual analogue scale (VAS) score was 6.9±1.0, and the the kyphotic Cobb angle of the stenosis segment was (34.62±10.76)°. The operation time, intraoperative blood loss, and complications were recorded. VAS score was used to evaluate the back pain, JOA score was used to evaluate the thoracic spinal cord function and the JOA improvement rate was calculated, and the kyphotic Cobb angle of the stenosis segment was measured and the Cobb angle improvement rate was calculated.
Results
The operation time ranged from 210 to 340 minutes, with a mean of 271.62 minutes; intraoperative blood loss ranged from 900 to 2 100 mL, with a mean of 1 458.75 mL; the number of resected vertebral plates ranged from 4 to 8, with a mean of 6.1; dural tears and cerebrospinal fluid leakage occurred in 3 cases, and the incisions healed by first intention. All 8 cases were followed up 12-26 months, with a mean of 18.3 months. There was no complication such as loosening of internal fixator, breakage of screws and rods, and no significant progress of ossification. At last follow-up, the VAS score was 1.4±0.7, the JOA thoracic spinal function score was 9.8±0.7, and the the kyphotic Cobb angle of the stenosis segment was (22.12±8.28)°, all of which significantly improved when compared with preoperative ones (t=11.887, P<0.001; t=13.015, P<0.001; t=7.395, P<0.001). The JOA improvement rate was 81.06%±10.93%, of which 5 cases were rated as excellent and 3 cases as good; the Cobb angle improvement rate was 36.51%±14.20%.
Conclusion
Laminectomy, posterior longitudinal ligament ossification block release combined with dekyphosis orthopedic surgery using ultrasonic bone scalpel system is a safe, effective, and simple method for the treatment of multisegmental T-OPLL, which is a feasible option.
Keywords: Thoracic ossification of posterior longitudinal ligament, spinal stenosis, ultrasonic bone scalpel
胸椎后纵韧带骨化症（thoracic ossification of posterior longitudinal ligament，T-OPLL）是一种罕见但危害严重的脊柱疾病，可导致椎管狭窄、脊柱后凸、压迫脊髓和神经根，引起脊髓损伤和神经功能障碍等，严重影响患者生活质量。T-OPLL发病率为0.44%～8.92%，主要见于亚洲人群[1-3]。其中多节段T-OPLL多见，可同时并发胸椎黄韧带骨化，导致胸脊髓腹背侧同时受压[4]。T-OPLL早期可无症状，后期出现神经症状，并呈现进行性加重，出现神经症状后保守治疗无效，需要手术减压治疗。传统治疗方法包括椎板切除术和后纵韧带骨化块切除减压术，以减轻脊髓和神经根的压迫。对多节段T-OPLL，无论是采用前路的后纵韧带骨化块切除减压，还是后路的脊髓360° 减压、骨化块整体前移法减压，都存在手术时间长、出血量大、创伤大以及神经损伤等并发症发生率高的缺点，而且术后神经功能恶化比例为7%～33%[5-6]。
近年来，随着医疗技术的进步，超声刮匙作为一种新型手术工具被引入脊柱外科领域。其利用高频振动实现对骨组织的精准切割，同时避免了对软组织和神经结构的损伤。研究表明[7-8]，超声刮匙在骨化病变切除和椎板切除术中的应用具有显著优势。然而在保证脊髓减压的前提下，如何减少对长节段后纵韧带骨化块的切除，从而减少对脊髓的干扰，仍然是一个亟待解决的问题。对长节段T-OPLL，我们采用超声骨刀切除病变节段的椎板，然后在后凸及狭窄严重部位采用超声刮匙切断骨化块、去后凸矫形内固定治疗，通过间接减压手术方式使脊髓获得减压。现回顾分析2020年1月—2023年4月，我们采用该方法治疗的8例多节段T-OPLL患者临床资料，以期探索一种综合性治疗方案，提高手术整体疗效。报告如下。
1. 临床资料
1.1. 一般资料
本组男3例，女5例；年龄41～67岁，平均57.1岁。病程3～74个月，平均33.4个月。主要临床症状为进行性双下肢麻木无力、行走不稳，有胸背部疼痛者3例，大小便功能障碍者5例；7例表现为下肢肌张力增高、腱反射亢进、Babinski征阳性，1例为下肢肌力减弱、皮肤感觉减退、腱反射减弱、病理征阴性。8例均存在多节段胸椎后纵韧带骨化，骨化节段4～8节；5例合并多节段黄韧带骨化。术前日本骨科协会（JOA）胸脊髓功能评分为（4.3±0.9）分，疼痛视觉模拟评分（VAS）为（6.9±1.0）分，胸椎管狭窄节段后凸Cobb角为（34.62±10.76）°。患者详细资料见表1。
表 1.
Clinical data of the patients
患者临床资料
| 序号 No. |
年龄 （岁） Age (years) |
病程（月） Disease duration (months) |
骨化节段 （节） Ossified segment (segment) |
手术时间 （min） Operation time (minutes) |
术中出血量 （mL） Intraoperative blood loss (mL) |
随访时间 （月） Follow-up time (months) |
术前/术后后凸Cobb角（°） Pre-/post-operative Cobb angle (°) |
术前/术后JOA 评分（分） Pre-/post-operative JOA score |
术前/术后VAS 评分（分） Pre-/post-operative VAS score |
| 1 | 41 | 20 | 4 | 230 | 1360 | 18 | 22/8 | 3/10 | 6/2 |
| 2 | 60 | 3 | 7 | 263 | 1520 | 12 | 41/26 | 4/11 | 7/1 |
| 3 | 56 | 74 | 8 | 340 | 2100 | 21 | 24/20 | 4/9 | 5/1 |
| 4 | 51 | 40 | 5 | 210 | 900 | 18 | 55/38 | 6/10 | 7/3 |
| 5 | 57 | 46 | 4 | 290 | 1150 | 16 | 36/22 | 5/9 | 7/1 |
| 6 | 67 | 44 | 5 | 223 | 920 | 26 | 26/20 | 4/10 | 8/1 |
| 7 | 52 | 15 | 6 | 327 | 1750 | 13 | 37/23 | 4/9 | 8/1 |
| 8 | 67 | 57 | 7 | 290 | 1970 | 22 | 36/20 | 4/10 | 7/1 |
1.2. 手术方法
患者采用全身麻醉，取胸腹部悬空的俯卧位，行神经电生理监护。采用后正中切口，显露病变节段及上、下各2个节段的椎板和关节突，在O臂X线机导航下植入胸椎椎弓根螺钉。应用超声骨刀在病变节段椎板两侧外缘（椎板沟处）切断椎板，然后从上、下端掀起椎板，分离黄韧带与硬膜的粘连，直至最狭窄处，采用“揭盖法”整块切除椎板，完成脊髓后方减压。在连续性后纵韧带骨化块的后凸顶点、压迫最严重的椎间隙部位，应用超声刮匙（图1）刮除脊髓侧方的骨质，直至椎体后壁，完成侧后方显露并保护硬膜囊；应用超声刮匙刮除椎间隙处的后纵韧带骨化块，先成V形刮除部分骨化块，然后从对侧扩大脊髓侧方并刮除椎间隙处骨化块直至断开。安装直连接棒，并向截骨点的头、尾端螺钉间加压，使该椎间隙闭合，完成“去后凸”矫形。矫形过程中采用神经电生理监测体感诱发电位，及时发现并避免脊髓神经损伤。将病变节段的横突皮质骨磨除，植入颗粒状自体骨，行横突间植骨融合术。冲洗术野，彻底止血后放置负压引流，逐层关闭切口。
图 1.
Ultrasonic curettes and various types of curette heads
超声刮匙及各种型号刮匙头
1.3. 围术期处理及疗效评价指标
手术当日应用地塞米松20 mg，术后第2、3天改为10 mg/d。术后应用甘露醇250 mL，2～3次/d，共5 d。术后48～72 h或引流量<50 mL/d时拔除引流管。对术后出现脑脊液漏者，行切口局部加压包扎24～48 h，引流管接防反流的引流袋，维持常压引流至术后4～5 d，待引流液清亮后拔除。术后即刻指导患者开始下肢功能锻炼，拔除引流管后开始下床活动。
记录手术时间、术中出血量及并发症发生情况。采用VAS评分评估患者腰背部疼痛；JOA评分评价胸脊髓功能，并按以下公式计算JOA改善率：（术后评分−术前评分）/（11−术前评分）×100%，≥75%为优，50%～75%为良，25%～50%为一般，<25%为差。于侧位X线片上测量狭窄节段后凸Cobb角[9]，即连续性后纵韧带骨化块上缘对应椎体的上缘与骨化块下缘对应椎体的下缘夹角（图2），并按以下公式计算后凸Cobb角改善率：（术前后凸Cobb角−术后后凸Cobb角）/术前后凸Cobb角×100%。
图 2.
Schematic diagram for measuring Cobb angle of stenosis segment
狭窄节段后凸Cobb角测量示意图
1.4. 统计学方法
采用SPSS19.0统计软件进行分析。计量资料经Shapiro-Wilk正态性检验，均符合正态分布，数据以均数±标准差表示，手术前后比较采用配对t检验；检验水准α=0.05。
2. 结果
本组患者手术时间210～340 min，平均271.62 min；术中出血量900～2100 mL，平均1458.75 mL。切除椎板4～8节，平均6.1节。3例术中出现硬膜撕裂及脑脊液漏，其中2例经严密缝合、加压包扎及引流4～5 d，切口Ⅰ期愈合；1例术中行人工硬膜缝合，术后未出现脑脊液漏。其余患者切口均Ⅰ期愈合。8例患者均获随访，随访时间12～26个月，平均18.3个月。无内固定物松动、断钉、断棒等并发症发生，骨化块未见明显进展。末次随访时，VAS评分为（1.4±0.7）分，JOA胸脊髓功能评分为（9.8±0.7）分，狭窄节段后凸Cobb角为（22.12±8.28）°，均较术前显著改善，差异有统计学意义（t=11.887，P<0.001；t=13.015，P<0.001；t=7.395，P<0.001）。JOA改善率为81.06%±10.93%，其中优5例、良3例，优良率100%；后凸Cobb角改善率为36.51%±14.20%。见图3，表1。
图 3.
Case 5, a 57-year-old male patient with T4-7 T-OPLL
例5，男，57岁，T4～7 T-OPLL
a、b. 术前正侧位X线片示胸椎退变；c、d. 术前CT矢状位示T4～7连续性后纵韧带骨化，突入椎管，狭窄节段后凸Cobb角36°；e. 术前MRI T2WI示T5～7后纵韧带骨化、T4～7黄韧带骨化，相应脊髓前后方均受压；f、g. 术后1周正侧位X线片示T3～8椎弓根螺钉位置良好；h、i. 术后1周CT矢状位示T4～7椎板切除，T5、6后纵韧带骨化块切断并去后凸，狭窄节段后凸Cobb角22°；j. 术前（上）及术后1周（下）胸椎CT横断位对比示后纵韧带骨化块已被切除，环形减压；k、l. 术后1年CT三维重建示脊柱后外侧植骨融合，椎管内后纵韧带骨化块未进展
a, b. Preoperative anteroposterior and lateral X-ray films showed degeneration of the thoracic spine; c, d. Preoperative sagittal CT showed the continuous ossification of the posterior longitudinal ligament at T4-7, protruding into the spinal canal, and the Cobb angle for the thoracic stenosis segment was 36°; e. Preoperative MRI T2WI showed ossification of the posterior longitudinal ligament at T5-7 and ossification of the ligamentum flavum at T4-7, and the anterior and posterior parts of the spinal cord were compressed; f, g. Anteroposterior and lateral X-ray films at 1 week after operation showed that the pedicle screws of T3-8 were well positioned; h, i. Sagittal CT at 1 week after operation showed T4-7 laminectomy, T5, 6 posterior longitudinal ligament ossification block was cut and dekyphosis, and the Cobb angle for the thoracic stenosis segment was 22°; j. Preoperative (upper) and postoperative 1 week (lower) horizontal CT of the thoracic spine showed that the ossification of the posterior longitudinal ligament had been resected and circular decompression had been performed; k, l. CT three-dimensional reconstruction at 1 year after operation showed fusion of the posterolateral bone graft and no progress of ossified mass of the posterior longitudinal ligament in the spinal canal
3. 讨论
3.1. 多节段T-OPLL手术方式的选择
连续性多节段T-OPLL的手术方式，可采用胸椎前路行椎体切除、骨化块切除实现直接减压。胸椎的生理性后凸结构更利于胸髓向腹侧漂移，从而获得理想减压效果，但前路手术入路复杂，对连续性多节段T-OPLL需切除多个椎体，导致创伤大，内植物由于较长容易松动移位，术后并发症发生率高[9-10]。另一种常见手术方法是通过胸椎后路进行脊髓360° 环形减压。该方法首先切除椎板和双侧关节突的内侧部分，然后采用涵洞塌陷法切除骨化块，此术式存在较高的脊髓损伤和出血风险[8，10-13]。Min等[14]报道了一组多节段T-OPLL患者的研究结果，经胸腔入路18例、经胸骨入路1例，术后神经功能恶化2例（10.5%）、脑脊液漏6例（31.6%）。与之相比，本研究采用后路切除病变节段的椎板后，在最接近后纵韧带骨化的后凸顶点只需切断骨化的后纵韧带，然后应用钉棒系统进行去后凸矫形，从而使脊髓后移，即可实现间接脊髓减压的目的。该手术方式最大程度地减少了对脊髓的操作刺激，出血量也较少。本组8例患者均未出现脊髓损伤或下肢瘫痪加重的症状，说明该术式提高了多节段T-OPLL手术的安全性。患者脊髓功能较术前明显改善，末次随访时JOA改善率81.06%±10.93%、优良率100%，提示该术式具有良好的临床效果。
3.2. 超声刮匙的使用技巧及安全性
多节段T-OPLL多合并黄韧带骨化，骨化的黄韧带及后纵韧带可与硬膜粘连，增加了硬膜损伤及脑脊液漏可能性，甚至可导致脊髓损伤。本组采用超声骨刀进行“揭盖式”胸椎管后壁整块切除，即先在双侧椎板外缘纵向切开，然后断开未粘连骨化的头、尾端，将整块椎管后壁提起，分离与硬膜囊之间的粘连，必要时应用尖刀紧贴椎板切开粘连，将椎管后壁整块切除。随后对骨化的后纵韧带后凸顶点或脊髓受压最严重部位，利用超声刮匙将脊髓侧方骨质刮除，显露脊髓侧方，切除双侧部分关节突并显露双侧椎间隙外侧缘；然后继续应用超声刮匙将骨化块部分切除，从两侧显露椎间隙，最后刮断骨化块。此过程严禁压迫或牵拉脊髓，以避免造成脊髓损伤。刮除椎间盘，在椎间隙内适量植骨后，加压螺钉闭合间隙，达到去后凸效果。由于全程应用超声骨刀系统进行操作和神经电生理监测体感诱发电位，因此对脊髓无震荡和刺激，有效保障了手术安全性。
超声骨刀和超声刮匙的应用能够有效减少术中出血量，提高术野清晰度，降低输血风险。由于其选择性切割特性，超声骨刀和超声刮匙能够避免对周围软组织和脊髓神经的损伤，减少术后神经并发症的发生。超声骨刀系统的高频振动能够精确切割骨组织，有助于彻底移除骨化病变，提高手术效果。
3.3. 该术式的优点及手术技巧
采用超声骨刀系统行椎板切除、骨化块切断，联合去后凸矫形技术治疗多节段T-OPLL的技术优势：① 只切断连续性后纵韧带骨化块顶端的连续性，无需过多切除后纵韧带骨化块，从而简化了手术流程。后纵韧带骨化块的进展与多种因素有关，其中微动应力是骨化物生长的重要因素。该手术技术通过进行内固定植骨融合，实现了牢固固定，从而减少了骨化物的进展[15-18]。② 全椎板切除后，进行去后凸矫形即可使脊髓后移，实现间接减压，取得良好临床疗效，同时减少了手术操作步骤。③ 应用超声骨刀及超声刮匙切骨的方法降低了手术风险和术中出血量[8]。
手术技术的减压技巧：① 在平行于脊髓方向的椎板外缘切开椎板，先从骨化块上、下端的未骨化部位开始操作；② 从未骨化部位开始掀起椎板并分离粘连，整体取下椎管后壁结构；③ 在预定的骨化块后凸顶点处扩大椎管侧方，远离脊髓以创造足够操作空间；④ 从脊髓两侧磨骨、切骨，以避免对硬膜造成刺激；⑤ 采用无震动的超声刮匙从外向内刮除部分骨化块并切断骨化块，禁止使用手枪式咬骨钳进行椎管内操作，以避免对脊髓造成压迫或刺激；⑥ 禁止牵开脊髓神经以切除骨化块，需要切除椎弓根和关节突，在脊髓外侧采用带角度的超声刮匙在脊髓腹侧进行刮除骨化块，然后刮除椎间盘。
综上述，采用超声骨刀系统行椎板切除、骨化块切断，联合去后凸矫形技术治疗多节段T-OPLL安全有效，操作较简便，是一种可行的方案。但本研究病例数少，随访时间较短，仍需要对大量病例进行远期疗效观察，以改进手术流程和操作技术。
利益冲突 在课题研究和文章撰写过程中不存在利益冲突；经费支持没有影响文章观点和对研究数据客观结果的统计分析及其报道
伦理声明 研究方案经漯河市中心医院医学伦理审查委员会批准（LH-KY-2020-001-021）
作者贡献声明 李玉伟：课题研究设计、实施及文章撰写；严晓云、潘传红、崔巍：病例随访、文章数据整理和统计分析；严晓云：文献检索、文章校对；王海蛟：对文章的知识性内容作批评性审阅、修改
Funding Statement
河南省医学科技攻关项目（LHGJ2020230937）
Henan Medical Science and Technology Research Project (LHGJ2020230937)
References
- 1.Tang R, Shu J, Li H, et al Surgical technique modification of circumferential decompression for thoracic spinal stenosis and clinical outcome. Br J Neurosurg. 2023;37(3):503–506. doi: 10.1080/02688697.2020.1774510. [DOI] [PubMed] [Google Scholar]
- 2.翟书珩, 胡攀攀, 刘晓光 术中超声辅助下环形减压术治疗多节段胸椎后纵韧带骨化症. 北京大学学报 (医学版) 2022;54(5):1021–1027. [Google Scholar]
- 3.Liu X, Zhai SH, Song QP, et al Long-term follow-up of multilevel thoracic ossification of the posterior longitudinal ligament following circumferential decompression via posterior approach: A retrospective study. Orthop Surg. 2022;14(2):298–305. doi: 10.1111/os.13182. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.刘法敬, 申勇, 丁文元, 等 经关节突入路治疗韧带骨化型胸椎管狭窄症. 中国修复重建外科杂志. 2011;25(3):311–315. [PubMed] [Google Scholar]
- 5.Zhai J, Guo S, Li J, et al Progression of spinal ligament ossification in patients with thoracic myelopathy. Orthop Surg. 2022;14(9):1958–1963. doi: 10.1111/os.13291. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Morishita S, Yoshii T, Inose H, et al Comparison of perioperative complications in anterior decompression with fusion and posterior decompression with fusion for thoracic ossification of the posterior longitudinal ligament—A retrospective cohort study using a nationwide inpatient database. J Orthop Sci. 2022;27(3):600–605. doi: 10.1016/j.jos.2021.03.010. [DOI] [PubMed] [Google Scholar]
- 7.李玉伟, 王海蛟, 崔巍, 等 超声刮匙在颈椎前路椎间盘切除融合术中应用的安全性和有效性评价. 中华医学杂志. 2020;100(9):669–673. doi: 10.3760/cma.j.issn.0376-2491.2020.09.005. [DOI] [Google Scholar]
- 8.Li C, Li Z, Li L, et al Angled ultrasonic bone curette-assisted circumferential decompression for thoracic myelopathy caused by severely anterior ossification. Orthop Surg. 2022;14(9):2369–2379. doi: 10.1111/os.13438. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.孙垂国, 陈仲强, 李危石, 等 后路椎管后壁切除、局限性后纵韧带骨化块切除联合去后凸治疗胸椎多节段后纵韧带骨化症. 中华骨科杂志. 2019;39(4):193–200. doi: 10.3760/cma.j.issn.0253-2352.2019.04.001. [DOI] [Google Scholar]
- 10.聂虎, 牛国旗, 周功, 等 3D打印技术结合新型胸椎椎弓根螺钉钉道探测器辅助胸椎椎弓根植钉的临床应用. 中国修复重建外科杂志. 2021;35(5):586–592. [Google Scholar]
- 11.Eto T, Aizawa T, Kanno H, et al Several pathologies cause delayed postoperative paralysis following posterior decompression and spinal fusion for thoracic myelopathy caused by ossification of the posterior longitudinal ligament. J Orthop Sci. 2022;27(3):725–733. doi: 10.1016/j.jos.2019.08.004. [DOI] [PubMed] [Google Scholar]
- 12.Aizawa T, Hashimoto K, Kanno H, et al Retrospective comparison of the surgical results for patients with thoracic myelopathy caused by ossification of the posterior longitudinal ligament: Posterior decompression with instrumented spinal fusion versus modified anterior decompression through a posterior approach. J Orthop Sci. 2022;27(2):323–329. doi: 10.1016/j.jos.2021.01.001. [DOI] [PubMed] [Google Scholar]
- 13.Yang P, Ge R, Chen ZQ, et al Treatment of thoracic ossification of posterior longitudinal ligament with one-stage 360 degree circumferential decompression assisted by piezosurgery. J Invest Surg. 2022;35(2):249–256. doi: 10.1080/08941939.2020.1839149. [DOI] [PubMed] [Google Scholar]
- 14.Min JH, Jang JS, Lee SH Clinical results of ossification of the posterior longitudinal ligament (OPLL) of the thoracic spine treated by anterior decompression. J Spinal Disord Tech. 2008;21(2):116–119. doi: 10.1097/BSD.0b013e318060091a. [DOI] [PubMed] [Google Scholar]
- 15.Wang ZC, Li SZ, Qu XF, et al Transdural circumferential decompression for thoracic spinal stenosis caused by beak-type ossification of the posterior longitudinal ligament: a technical note. Br J Neurosurg. 2023;37(5):1371–1374. doi: 10.1080/02688697.2020.1820942. [DOI] [PubMed] [Google Scholar]
- 16.Yoshihara H, Horowitz E, Nadarajah V Prevalence and characteristics of thoracic ossification of the posterior longitudinal ligament in 3299 Black patients: a cross-sectional study of a prospectively registered database. BMJ Open. 2022;12(8):e059238. doi: 10.1136/bmjopen-2021-059238. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Ando K, Nakashima H, Machino M, et al Postoperative progression of ligamentum flavum ossification after posterior instrumented surgery for thoracic posterior longitudinal ligament ossification: long-term outcomes during a minimum 10-year follow-up. J Neurosurg Spine. 2021;36(6):986–996. doi: 10.3171/2021.10.SPINE211091. [DOI] [PubMed] [Google Scholar]
- 18.Sun K, Zhang S, Yang B, et al The effect of laminectomy with instrumented fusion carried into the thoracic spine on the sagittal imbalance in patients with multilevel ossification of the posterior longitudinal ligament. Orthop Surg. 2021;13(8):2280–2288. doi: 10.1111/os.13147. [DOI] [PMC free article] [PubMed] [Google Scholar]