Thoracic cord compression caused by contiguous multilevel ossification of ligamentum flavum in Chinese patients

OBJECTIVE: To explore the epidemiology, clinical presentation, radiology and surgical treatment outcome in Chinese patients with myelopathy caused by contiguous multilevel ossification of ligamentum flavum. METHODS: Medical notes and imaging data of 18 Chinese patients (14 males and 4 females, aged 43-72 years, mean: 57 years) with myelopathy caused by contiguous multilevel ossification of ligamentum flavum were studied retrospectively in this article. The diagnosis was based on clinical examination, X-ray films, computerized tomography (CT) and magnetic resonance imaging (MRI) scanning results and pathological results. Sixteen patients were treated by laminectomy and two by laminoplasty. The average follow-up duration was 34 months (range, 28-49 months). The outcome was evaluated by Japanese Orthopaedics Association (JOA) score. RESULTS: The average time for occurring clinical symptoms was 7.5 months (range, 2 days-16 months). All the 18 cases presented with clinical evidences of chronic and progressive thoracic spinal cord compression, which included bilateral leg weakness, spastic gait, numbness in lower limbs, paresthesia in terminal and perineum, and urinary incontinence. Neurological examination revealed severe spastic paraparesis, absence of abdominal reflexes, and reduction of the sensory function below the compression level. The mean JOA score before operation was 3.6 (range, 0-6). MRI and CT scans of the thoracic spine confirmed the presence of contiguous multilevel ossification of the ligamentum flavum. The mean recovery rate after surgery in terms of JOA score was 66.3% (range, 33.3%-100%), with a mean final JOA score of 8.3. Thoracic decompression laminectomy or laminoplasty could result in a good postoperative outcome. CONCLUSIONS: Contiguous multilevel ossification of the ligamentum flavum is not a common cause of myelopathy in Chinese population and should be treated as early as possible. MRI and CT scan examinations may diagnose the presence of thoracic ossification of ligamentum flavum (OLF). Posterior decompression, especially with en bloc dissection of the laminae, can obtain satisfactory results.     

局灶性胸椎黄韧带骨化症的诊治效果分析

目的探讨局灶性胸椎黄韧带骨化（ossification of the ligamentum flavum,OLF）致椎管狭窄的临床特点、手术治疗效果及影响因素。方法对手术治疗的21例胸椎OLF病例进行回顾性研究分析,手术均采用后路椎板（半椎板或全椎板）切除减压术。采用改良胸椎日本骨科学会（Japanese Orthopaedic Association,JOA）评分法和Epstein标准评估最终随访临床效果。分析患者年龄、术前病程、椎管面积残余率和术前胸椎JOA评分与手术疗效相关性。结果术后随访平均34.3个月。JOA评分术前平均7.7分;末次随访时平均10.2分,改善率为75.8%。Epstein标准：优13例,良5例,可3例。患者椎管面积残余率、术前胸椎JOA评分与手术疗效均呈正相关,相关系数分别为0.41（P〈0.05）、0.53（P〈0.05）。结论局灶性OLF临床表现较复杂,必须根据临床特点、影像学及电生理检查进行综合分析并作出诊断。后路椎板切除减压术是治疗局灶性胸椎OLF并椎管狭窄症的有效方法。患者椎管狭窄程度、术前胸椎JOA评分是影响手术疗效的重要因素。     

氟与黄韧带骨化

目的：探讨氟与黄韧带骨化的关系。方法：采用氟离子电极等方法测定１１ 例胸椎黄韧带骨化症（ 包括５ 例氟骨症） 患者血清及黄韧带标本中氟、钙含量,分别选取胸腰椎急性外伤性截瘫及腰椎管狭窄患者为正常及退变对照。结果：氟骨症骨化患者与非氟骨症骨化患者黄韧带中氟、钙含量均显著增高（ Ｐ＜ ０－０１） 。结论：氟在黄韧带骨化中起重要作用,可能是诱导退变黄韧带进一步骨化的重要诱因。     

胸椎黄韧带骨化的MRI分型对胸椎管狭窄手术方法选择的影响

目的 探讨胸椎黄韧带骨化的MRI分型对胸椎管狭窄手术方法 选择的影响.方法 1991年6月至2006年2月,黄韧带骨化性胸椎管狭窄患者34例,男23例,女11例;年龄33～72岁,平均52.6岁.均经CT确诊,并按MRI特征分型,选择不同手术方法 .孤立型5例,选择椎管后壁切除减压法;连续型20例,选择全椎板整块漂浮法减压;跳跃型或合并其他部位压迫型7例,全椎板整块漂浮法-期或分期减压;复合型2例,次环状减压法.记录手术前、后6、12、24、36个月JOA评分.采用Epstein标准评价手术效果.对不同时期JOA评分进行统计学分析.结果 30例患者术后获得36个月的随访.JOA评分比较,术后不同时期均与术前有显著差异(P＜0.05);术后不同时期两两比较,6个月与12个月、12个月与24个月、24个月与36个月比较,差异均无统计学意义(P＞0.05);但术后6个月与24个月比较,差异有统计学意义(P＜0.05).按Epstein标准评价,术后36个月时30例患者:优18,良5例,改善6例,差1例;优良率为76.7%.结论 正确分辨胸椎黄韧带骨化的MRI特征有利于确定胸椎管狭窄的具体手术范围及术式.     

后路全椎板切除减压并椎弓根内固定治疗胸椎后纵韧带骨化合并黄韧带骨化

目的探讨对胸椎后纵韧带骨化(ossification of posterior longitudinal ligament,OPLL)合并黄韧带骨化(ossification of ligamentum flavum,OLF)患者行后路全椎板切除减压并椎弓根内固定治疗的临床疗效。方法回顾性研究2008年7月~2013年4月,15例胸椎OPLL并OLF患者行后路全椎板切除减压并椎弓根内固定术治疗。分别统计患者一般情况、手术时间、出血量、卧床时间、术后并发症发生率、术前术后日本骨科学会(Japanese Orthopaedic Association,JOA)评分,并进行比较。结果平均随访38.7个月,患者术前、术后3个月及末次随访时JOA评分分别为3.9±1.2、8.1±2.2及10.3±2.5,差异具有统计学意义(P<0.05)。术中1例患者出现脑脊液漏,术后1例患者出现浅表伤口感染,1例患者出现血肿。结论胸椎OPLL并OLF患者行全椎板切除减压并椎弓根内固定术治疗,可获得满意的临床疗效。但该术式容易造成严重脊髓损伤,对术者技巧要求较高。     

胸椎黄韧带骨化与腰椎黄韧带退变的病理及基本代谢元素的比较研究

目的：探讨胸椎黄韧带骨化的病因。方法：对１４例胸椎黄韧带骨化（包括５例氟骨症）及１４例腰椎管狭窄症患者手术切除的黄韧带标本作病理研究；对患者血清及黄韧带采用雾化原子吸收法等方法测定钙、磷、镁、锌、铜、锰、钼、氟含量，取急性外伤性截瘫患者为对照。结果：（１）骨化黄韧带初期的病理改变与黄韧带退变性质类似；（２）除氟元素外，７种基本代谢元素在骨化与退变患者血清及黄韧带中含量均呈基本一致的变化规律；（３）非氟骨症骨化患者黄韧带中氟含量显著增高（Ｐ＜０．０１）。结论：本文证实胸椎黄韧带骨化发生于黄韧带退变的基础之上，但退变不直接导致骨化，元素氟是诱导退变黄韧带进一步骨化的重要诱因。     

胸椎黄韧带骨化症合并脊髓型颈椎病手术方案选择

目的 探讨胸椎黄韧带骨化(ossification of ligamentum flavum,OLF)合并脊髓型颈椎病(cervical spondylotic myelopathy,CSM)手术方案的选择.方法 1991年1月至2003年1月,手术治疗胸椎OLF合并CMS患者56例,其中40例获得2年以上随访,男22例,女18例;确诊时年龄27～70岁,平均58岁;病程1～120个月,平均16.5个月.其中OLF 25例,OLF合并后纵韧带骨化(ossification of posterior longitudjnal ligament,OPLL)12例,OLF合并胸椎间盘突出3例;同时合并颈椎OPLL 23例,退变性颈椎管狭窄17例.18例一期行颈后路"单开门"椎板成形术+上胸椎椎管后壁切除术,9例一期行胸椎管后壁切除术,13例分期行颈后路和胸椎管后壁切除术.结果 40例患者的随访时间为24～227个月,平均67.5个月.根据改良Epstein手术疗效评定标准评价优良率,18例一期行颈后路"单开门"椎板成形术+上胸椎椎管后壁切除术者为88.9%(16/18),9例行胸椎管后壁切除术者为66.7%(6/9);13例分期行颈后路和胸椎管后壁切除术者为53.8%(7/13).结果 显示分期手术者术后优良率低于一期手术者,手术间隔时间在1年以内者的优良率高于间隔1年以上者.结论 上胸椎OLF合并CSM者应一期行颈椎和上胸椎脊髓减压术;下肢症状严重而上肢症状轻微者应先行胸脊髓减压术;上、下肢症状均重者应一期或分期行颈脊髓减压术和胸脊髓减压术,而分期手术者的手术间隔时间不宜过长.     

全椎板薄化层揭法治疗胸椎管狭窄症

目的 探讨采用全椎板薄化层揭法治疗由胸椎黄韧带骨化(ossification of ligamentum flavum,OLF)和胸椎后纵韧带骨化(ossification of posterior longimental ligament,OPLL)引起的胸椎管狭窄症的特点及疗效.方法 回顾121例胸椎管狭窄症患者的临床资料,男51例,女70例;年龄45～71岁,平均54.8岁;单纯胸椎OLF 72例,单纯胸椎OPLL 21例,合并胸椎OLF和OPLL 28例.对胸椎OLF和胸椎OPLL均采用全椎板薄化层揭法进行治疗.统计病变的节段与平面,测量椎体矢状位夹角,计算椎管面积残余率.采用日本骨科协会(Japanese Orthopaedic Association,JOA)评分系统对术前、术后脊髓功能进行评分并比较.结果 胸椎OLF的发病,下胸椎占77.0%(137/178);胸椎OPLL,上胸椎占81.1%(43/53).121例患者平均上胸椎后凸角31.5°±6.8°,下胸椎后凸角9.4°±3.5°.椎管面积残余率＞80%时,JOA评分从术前的(7.7±1.4)分提高到术后的(9.5±1.6)分;椎管面积残余率在80%～50%时,JOA评分从(5.2±1.8)分改善到(8.6±2.1)分;椎管面积残余率＜50%时,JOA评分从(4.8±1.4)分改善到(5.6±1.3)分.结论 胸椎OLF好发于下胸椎,胸椎OPLL好发于上胸椎.术前椎管面积残余率对预后有重要意义.只要临床症状和影像学表现相对应,应尽早手术,手术应尽量切除骨化物.胸椎管狭窄症术后易复发,再次手术更应注意减压范围和减压技巧.     

胸椎黄韧带骨化症合并脊髓型颈椎病的临床诊断要点

目的总结胸椎黄韧带骨化症合并脊髓型颈椎病的临床特点,探讨避免漏诊胸椎黄韧带骨化症的方法。方法对比分析胸椎黄韧带骨化症合并脊髓型颈椎病和单纯脊髓型颈椎病的临床表现、影像学表现、JOA评分的异同。结果共收集35例胸椎黄韧带骨化症合并脊髓型颈椎病病例,其中20例合并连续型颈椎后纵韧带骨化和/或弥漫性特发性骨肥厚症,14例是因颈椎MRI发现上胸椎黄韧带骨化后进一步行全胸椎MRI检查后确诊;胸椎黄韧带骨化症合并脊髓型颈椎病者的上肢功能评分构成比较单纯脊髓型颈椎病者为高(p<0.05)。结论胸椎黄韧带骨化症合并脊髓型颈椎病的诊断须综合分析病史、体征和影像学表现;JOA脊髓功能评分可以为其确诊提供帮助。     

Thoracic Myelopathy Secondary to Ossified Ligamentum Flavum

Summary. Summary. Background: Focal ossification of the ligamentum flavum (OLF) forms one of the rare causes of thoracic myelopathy. The lower thoracic spine is most frequently affected and the patients present with initial posterior column disturbances followed by progressively increasing spastic paraparesis. The pathogenesis of OLF has not been conclusively established. Method: Five patients with thoracic myelopathy due to OLF underwent decompressive laminectomy and excision of the ligamentum flavum. Their MRI delineated a linear or beak like excrescence, uniformly hypo-intense on T1 and T2 weighted images, situated posterior to the thecal sac. A comparison between the pre-operative neurological status and the status at follow-up was done using Harsh's myelopathic grading. Finding: Decompressive laminectomy followed by the drilling of the OLF and its excision, occasionally along with the adherent outer layer of the dura, resulted in significant improvement in motor weakness and tingling sensations. However, at the last available follow-up, none of the patients had retained their ability to run briskly (grade I) and all of them had residual spasticity. Interpretation: OLF may significantly contribute to a spatial reduction of the thoracic spinal canal resulting in paraparesis. The T2 weighted sagittal image of the magnetic resonance imaging (MRI) is the modality of choice for screening of the longitudinal extent of the OLF. A rapid neurological improvement occurs following decompressive laminectomy and excision of the OLF. However, the persistence of residual spasticity at follow-up may be due to irreversible changes within the cord by the significant thecal compression and the delay between the onset of initial symptoms and signs and surgical decompression.     

胸椎后纵韧带骨化致椎管狭窄症的临床特征和手术治疗方法

目的 探讨胸椎后纵韧带骨化致椎管狭窄症的临床特征和手术治疗方法.方法 2004年1月至2009年3月,手术治疗胸椎后纵韧带骨化致椎管狭窄症患者21例,男13例,女8例;年龄34～71岁,平均51.2岁;病程2～50个月,平均11个月.病变位于上胸段(T1～T4)4例,中胸段(T5～T8)7例,下胸段(T9～T12)10例;合并黄韧带骨化9例,合并颈椎后纵韧带骨化8例.11例行后路椎板切除术,10例行侧前方减压术.结果 后路椎板切除手术时间90～240 min,平均140 min.侧前方减压手术时间110～360min,平均240min.术后患者症状未加重,未出现神经系统并发症、无蛛网膜下腔感染和伤口感染.术后6个月日本骨科协会(Japanese Orthopaedic Association,JOA)评分为8～15分,平均(9.17±1.63)分;其中神经功能改善率8例为优,6例为良,5例为可,2例为差,优良率为66.7%.术后12个月JOA评分为8～15分,平均(10.23±1.64)分;其中神经功能改善率8例为优,7例为良,4例为可,2例为差,优良率为71.4%.结论 胸椎后纵韧带骨化致椎管狭窄临床表现多样,常合并颈椎后纵韧带骨化和黄韧带骨化,后路椎板切除术和侧前方减压术有较好疗效.     

手术治疗胸椎黄韧带骨化症84例疗效分析

目的总结84例胸椎黄韧带骨化（ossification of the ligamentum flavum，OLF）导致的脊髓背侧压迫出现胸脊髓病变患者手术减压的临床疗效。方法分析资料完整的84例OLF患者（男，63例；女，21例，平均年龄为59岁）手术前后JOA评分、Nurick分级的变化和神经功能恢复率，评价手术疗效。结果平均随访28个月（6—56个月），病程短、MRI没有脊髓高信号的患者经过胸椎椎板切除减压后运动无力和步态异常明显改善，全部病例的步态和痉挛状态均有改善。JOA评分：优28例，良32例，可15例，差9例。优良率为71．4％，有效率为89．3％。结论OLF导致的脊髓损害症状非手术治疗无效，病程短、脊髓髓内没有高信号改变的患者手术效果通常比较好。     

Thoracic myelopathy caused by ossification of the ligamentum flavum. Clinicopathologic study and surgical treatment

The authors reviewed 14 patients with thoracic myelopathy caused by ossification of the ligamentum flavum (OLF). The predominant locality of symptomatic OLF was at the thoracolumbar junction, particularly at T10-11 followed by T11-12. At the level of the thickest OLF in each patient, there were three types of OLF from computed tomography and operative findings: a lateral type in 3 patients, diffuse in 8, and thickened nodular in 3. The diagnosis of OLF-related thoracic spinal canal stenosis was best made by enhanced computed tomography. Histologic study revealed that the developmental mode of OLF was mainly endochondral ossification. Numerous fibrocartilaginous cells were found in the increased and swollen collagen fibers forming the hypertrophic ligamentum flavum (HLF). Ossification extended along the superficial layer of HLF. The size or extension of OLF was relevant to the corresponding diathesis of spinalhyperostosis. Results of laminectomy for OLF were poor because of the high occurrence of complications early on or later deterioration. Therefore, laminoplasty is recommended as a successful procedure for OLF-related thoracic myelopathy, avoiding further local mechanical stress due to tensile force.     

Surgery for thoracic myelopathy caused by ossification of the ligamentum flavum

BACKGROUND: Ossification of the ligamentum flavum overlying the lower thoracic spine frequently produces myelopathy. This study analyzed the postoperative outcomes after decompressive laminectomy for thoracic OLF. METHODS: We retrospectively studied 13 patients (10 male, 3 female; mean age, 58 years; range, 39-69). The mean follow-up duration was 66 months (range, 21-107). All patients had undergone decompressive laminectomy and excision of the OLF. The clinical course was evaluated according to the Frankel grading system and JOA scores. The number of vertebral segments demonstrating OLF, the most frequent level of thoracic cord involvement, and spine lesions coexisting with OLF were determined by MR imaging. RESULTS: By the Frankel system, 7 of 13 patients improved by one grade, whereas the others, classified as grade D, were unchanged after surgery. Using the JOA score, the functional improvement was excellent in 3 patients, good in 4, fair in 2, and unchanged in 4. The number of vertebral segments demonstrating OLF included 4 levels in 2 patients, 3 levels in 2 patients, 2 levels in 5 patients, and 1 level in 4 patients. Ossification of the ligamentum flavum occurred most frequently at the T10/T11 level. Tandem cervical and lumbar lesions were present in 6 patients. CONCLUSIONS: Decompressive laminectomy for excision of OLF resulted in clinical improvement using the Frankel grading system in 7 of 13 patients. In myelopathy patients with OLF, preoperative MR imaging of the entire spine is necessary because other coexisting spinal lesions may be present.     

胸椎黄韧带骨化症手术治疗效果分析

目的:探讨胸椎黄韧带骨化症手术方法和疗效。方法:回顾性分析自2006年10月至2009年10月采用半关节突全椎板切除术手术方法治疗胸椎黄韧带骨化症6例,男4例,女2例;年龄45～66岁,平均55.2岁。术后采用JOA评分法从下肢运动、膀胱功能两方面对疗效进行评定。结果:所有患者获随访,时间2～18个月,平均10.5个月。下肢功能按JOA评定标准:优4例,良1例,差1例。1例差的患者因为脊髓压迫时间过长,MRI显示T2加权像脊髓高信号导致不可逆的脊髓变性及合并有精神分裂症。结论:半关节突全椎板切除减压是胸椎黄韧带骨化症目前较好的手术方式,术中彻底减压和实时的脊髓保护是手术取得成功的关键。     

Clinical features and surgical outcomes of patients with thoracic myelopathy caused by multilevel ossification of the ligamentum flavum

Background contextThoracic myelopathy caused by multilevel (three or more levels) ossification of the ligamentum flavum (OLF) is rare. Little is known about its clinical features, and the surgical outcomes along with its related factors are also unclear.PurposeTo describe the clinical features, assess the safety and effectiveness of surgical decompression, and determine the prognostic factors relevant for patients with thoracic myelopathy caused by multilevel OLF.Study design/settingA retrospective clinical study.Patient sampleSeventy-five consecutive multilevel OLF patients who underwent surgical decompression were analyzed.Outcome measuresModified Japanese Orthopedic Association (JOA) scale and the recovery rate.MethodsPatients who underwent surgical decompression for symptomatic multilevel OLF during January 1996 to June 2010 were all included. Clinical data were collected from medical and operative records; patients were evaluated by using the JOA scale preoperatively and during the follow-up. Correlations between the surgical outcome and various factors were also analyzed.ResultsForty-three men and 32 women with a mean age of 54.7 years (range 36–78 years) were included. The mean number of involved levels is 4.6 and contiguous OLF presented in 73.3% of these patients. The most common involved levels were T10/T11 (15.4%), T9/T10 (13.3%), and T11/T12 (12.5%). Coexisting spinal disorders were found in 41 patients (54.7%). Preoperative evaluation showed the mean JOA score was 5.8±1.7; 37.3% of these patients had mild myelopathy, 53.3% had moderate myelopathy, and 9.3% had severe myelopathy. All patients received posterior laminectomy. The JOA score (mean 8.2±2.1) significantly increased postoperatively (p<.05), and multiple regression analysis showed that preoperative duration of symptoms and preoperative JOA score were important predictors of surgical outcome.ConclusionsLaminectomy with partially internal fixation is safe and effective in treatment of patients with symptomatic multilevel OLF. The results of our study show that preoperative JOA score and preoperative duration of symptoms were important predictors for the clinical outcome.     

合并腰椎疾患的下胸椎黄韧带骨化临床诊治

目的探讨合并腰椎疾患的下胸椎黄韧带骨化临床特点及诊治方法。方法下胸椎黄韧带骨化同时存在腰椎疾患的患者23例,诊断结合X线、椎管造影、CT、MRI检查,体征以肌张力增高和深反射异常为特点;患者均采用病变节段全椎板减压手术治疗。结果23例均获随访,时间10-36个月,手术减压1-3节胸椎椎板,患者在末次随访时都有不同程度的神经功能改善。术后功能恢复优4例,良13例,可6例。术后到末次随访时无一例患者因腰椎疾病而再次接受手术。结论合并腰椎疾患的下胸椎黄韧带骨化需要注意将客观体征与多种影像学检查相结合,尽早诊断、早期手术。     

黄韧带骨化所致胸椎管狭窄症的诊断及手术治疗

目的：总结黄韧带骨化所致胸椎管狭窄症的诊断和治疗特点。方法：1995年9月－2000年12月手术治疗黄韧带骨化所致胸椎管狭窄症患12例，男8例，女4例，平均年龄55岁。该病常见于下胸椎，临床表现为多椎管狭窄引起的胸髓压迫症，其影像学检查具有特征性表现。所有病例均行整块半关节突全椎板切除术。结果：11例随访6－62个月，平均23个月。根据评定标准，优6例，良2例，中2例，差1例，优良率72．7％。结论：临床表现结合MRI和CT检查，是诊断胸椎黄韧带骨化的重要手段，整块半关节突全椎板切除术为治疗的有效术式。     

Transient paraparesis after laminectomy for thoracic ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum

STUDY DESIGN: Case report. OBJECTIVES: To report a case with thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF), in which postoperative paralysis occurred after laminectomy and was reversed after an additional posterior instrumented fusion. SETTING: A University Hospital in Japan. CASE REPORT: A 71-year-old woman, with a spastic palsy of both lower extremities, had OPLL and OLF at T10-T11, which pinched the spinal cord anteriorly and posteriorly. She underwent a laminectomy at T10-T11, and no further neurological deterioration was seen immediately after surgery. Over the next 18 h, however, myelopathy worsened, showing severe paraparesis. An additional posterior instrumented fusion at T7-L1 was performed without correction of the kyphosis. After fusion, neurological deficits gradually recovered, despite the presence of residual anterior impingement of spinal cord by the OPLL. CONCLUSIONS: The present case provides evidence for the possibility that laminectomy alone produces postoperative paralysis for combined thoracic OPLL and OLF, and we recommend that a posterior instrumented fusion should be added when posterior decompression is performed for this disorder.     

Surgical results and prognostic factors for thoracic myelopathy caused by ossification of ligamentum flavum: posterior surgery by laminectomy

Background

Thoracic ossification of ligamentum flavum (TOLF) of the spine is characterized by a heterotopic bone formation in the thoracic ligamentum flavum, which causes slowly progressing spinal cord injury. Surgical decompression is the most common treatment of choice for patients with compressive myelopathy due to TOLF. However, the surgical outcome is not always satisfactory.

Methods

To identify the predictors of surgical outcome, we retrospectively studied the associations between various clinical and radiological parameters and postoperative recovery in 78 patients who underwent decompressive laminectomy for thoracic myelopathy due to TOLF between October 1998 and June 2011. Surgical outcomes were assessed using modified Japanese Orthopedic Association (mJOA) recovery rate (RR)/outcome scores.

Results

At a minimum of 1 year after surgery for TOLF treatment, the postoperative clinical scores showed statistically significant changes with improvement in the JOA scores. The results indicated that a longer duration of preoperative symptoms, fused-type TOLF, and the degree of compression of the anteroposterior diameter and ossified region (middle thoracic OLF) was related to poor prognosis.

Conclusion

Early diagnosis and sufficient surgical decompression improved the functional outcomes of TOLF patients. The surgical risk is relatively higher due to the tenuous blood supply of the spinal cord and the limited spinal canal volume of the middle thoracic spine extending from T4 to T9.