Laminoplasty for the treatment of extramedullary intradural tumors in the thoracic and lumbar spine: greater than two‐year follow‐up

Objective: To investigate the outcome of a laminoplasty technique without additional instrumentation for fixation of laminae in the treatment of extramedullary intradural tumors in the thoracic and lumbar spine. Methods: Twenty‐four patients (15 men and 9 women) with extramedullary intradural tumors in the thoracic and lumbar spine were included in our study. The average age was 36.2 years (range 18 to 61 years). The pathological diagnosis was neurofibroma in 13, ependymoma in 6, lipoma in 2 and teratoma in 3 cases. All patients underwent the same laminoplasty surgery as follows: the laminae were reattached to their original sites, the ligaments (including the supraspinal, interspinal and yellow ligaments) were conserved, and primary stability of the re‐attached laminae was achieved with silk or nylon sutures. Results: Sixty‐six laminae were re‐implanted in 24 patients. The average length of follow‐up was 34.2 months (26.5 to 41 months). Fusion of the laminae was achieved in a mean of 4.5 months (3 to 6 months). Unilateral healing of the incision lines was observed in seven cases, including one with two‐level laminotomy, three with three‐level laminotomy and three with four‐level laminotomy. The other 17 cases underwent bilateral fusion. Conclusion: Fixing the laminae, spinous processes and ligaments with sutures can achieve satisfactory primary stability and high fusion rates for resected laminae. Additional instrumentation may be necessary in greater than three‐level laminoplasty.     

经椎板切开成形术切除椎管内肿瘤

【目的】探讨经椎板切开成形术切除椎管内肿瘤的临床经验。【方法】2010年6月至2013年6月采用后路椎板切开椎管内肿瘤切除后椎板复位成形术治疗16例椎管内肿瘤患者,16例均平均随访12个月,回顾性对比研究手术前后患者神经功能的变化情况。【结果】16例患者13例肿瘤全切,3例次全切除,术后神经根性疼痛均在1周内好转,肢体、躯干运动感觉障碍在3个月内逐渐改善。3例括约肌功能障碍患者中2例在半年内明显改善,1例改善不明显。所有患者均获得门诊随访,随访时间平均12个月。经M RI检查均未见肿瘤复发。2例患者因术中脊髓神经根牵拉术后出现单侧下肢无力,随访半年后1例恢复良好,1例无明显改善,未出现其他并发症。【结论】后路椎板成形治疗椎管内肿瘤安全可靠,疗效满意。     

Clinical Experience and Management of Cervico-Thoracic Epidural Hematoma

Spinal epidural hematoma (SEH) causing acute myelopathy is rare. The usual clinical presentation of a SEH is sudden severe neck or back pain that progresses toward paraparesis or quadriparesis, depending on the level of the lesion. Recent studies have shown that early decompressive surgery is very important for patient''s recovery. We experienced five patients of cervico-thoracic epidural hematomas associated with neurologic deficits that were treated successfully with surgical intervention.     

不同椎板减压范围对BioFlex系统生物力学的影响

【摘要】 目的：利用有限元方法分析比较不同椎板减压范围对脊柱动态内固定BioFlex系统生物力学的影响。方法：利用Mimics 10.01三维重建软件建立正常L3～L5几何模型并利用ProE逆向工程软件建立BioFlex系统几何模型,按临床术式进行组装并导入ANSYS Workbench 14.0有限元分析软件进行前处理建立四种L3～L5三维有限元模型：完整状态L3～L5模型（INT组）,L4-L5椎板减压+1/2关节突切除+Bioflex模型（MF-BF组）,L4-L5椎板减压+全关节突切除+Bioflex模型（TF-BF组）,L4-L5椎板减压+髓核摘除+Bioflex模型（D-BF组）;在各模型L3椎体的上表面以及上关节突的关节面轴向予1200N载荷和8Nm、8Nm、6Nm、4Nm力矩下模拟人体腰椎正常生理轴向载荷、前屈、后伸、侧弯和扭转,L5椎体的下表面及下关节突表面各节点六个方向自由度完全固定。测量各模型固定节段和邻近节段的活动度以及邻近节段的髓核间应力与关节突应力,并进行分析比较。结果：椎板减压并置入动态内固定Bioflex系统后,脊柱固定节段的活动度各减压组较INT组明显减小（P＜0.05）,其中TF-BF组前屈活动度减小幅度最大达77.2%,MF-BF组后伸、侧弯、旋转活动度减小幅度最大分别达37.4%、67.2%、83.1%;邻近节段的活动度各减压组较INT组增大（P＜0.05）,其中MF-BF组前屈活动度增大幅度最大达22.9%,TF-BF组后伸、侧弯活动度增大幅度最大分别达18.2%、32.1%,DF-BF组旋转活动度增大幅度最大达13.8%。不同状态下固定节段及邻近节段活动度MF-BF组、TF-BF组及D-BF组间波动幅度不大,两两比较差异无统计学意义（P＞0.05）。邻近节段关节突应力及髓核间应力各减压组较INT组明显增大（P＜0.05）,其中TF-BF组关节突应力在后伸、旋转活动时增大幅度最大分别达81.6%、77.3%,DF-BF组关节突应力在侧弯活动时增大幅度最大达60.5%,DF-BF组髓核间应力在前屈活动时增大幅度最大达46.6%,MF-BF组髓核间应力在后伸、侧弯、旋转活动时增大幅度最大分别达11.8%、63.5%、51.3%;邻近节段的关节突应力与髓核间应力在不同状态下各减压组间波动幅度不大,两两比较差异无统计学意义（P＞0.05）。结论：置入BioFlex系统后脊柱固定节段的活动度明显减小,邻近节段的活动度增大,固定与邻近节段活动度不随椎板减压范围的改变而明显改变;邻近节段关节突应力及髓核间应力明显增大,其大小不随椎板减压节段范围的改变而明显改变。     

体感诱发电位监测在脊柱外科手术应用中的影响因素

目的分析体感诱发电位(SEP)监测在脊柱外科手术应用中的影响因素,探讨其预测指标,初步建立SEP指标波幅差值异常变化时出血量及平均动脉压的预测模型。方法回顾性分析接受多节段椎板切除减压手术的86例患者的SEP监测资料,以SEP波幅差值异常变化作为SEP受影响的指标,与性别、年龄、身高、体质量、平均动脉压范围、出血量、手术时间、皮下针电极导线长度、电磨钻应用情况、气磨钻应用情况、电动手术床电源接通情况等11个指标进行Pearson或Spearman相关分析及多元线性回归,筛选影响SEP的相关因素。结果 SEP指标(波幅差值P40/N50)和出血量(P0.05)、平均动脉压波动范围(P0.05)、电磨钻使用情况(P0.05)、气磨钻使用情况(P0.05)、电动手术床电源接通情况(P0.05)5个因素存在相关关系,而与性别(P0.05)、年龄(P0.05)、身高(P0.05)、体质量(P0.05)、手术时间(P0.05)、皮下针电极导线长度(P0.05)不具有相关关系。平均动脉压50 mm H(1 mm Hg g=0.133 k Pa)或在50 mm Hg左右波动时,以及出血量较多且1 249 m L时,SEP的波幅将明显发生变化,接近甚至会低于基线水平,与术中脊髓、神经损伤表现相似。结论出血量、平均动脉压范围、电磨钻使用情况、气磨钻使用情况和电动手术床电源接通情况是SEP指标(P40/N50)的影响因素。     

The Comarr Memorial Award for Distinguished Clinical Service: The Legacy of A. Estin Comarr,MD

Abstract

Background

Subfascial wound suction drains are commonly used after spinal surgery to decrease the incidence of post-operative hematoma. However, there is a paucity of literature regarding their effectiveness.

Objective

To report four cases of post-operative spinal epidural hematoma causing massive neurological deficit in patients who had subfascial suction wound drains.

Methods

During an 8-year period, a retrospective review of 1750 consecutive adult spinal surgery cases was performed to determine the incidence, commonalities, and outcomes of catastrophic neurological deficit caused by post-operative spinal epidural hematoma.

Findings

Epidural hematoma causing major neurological deficit (American Spinal Injury Association B) was identified in 4 out of 1750 patients (0.23%). All four patients in this series had subfascial wound suction drains placed prophylactically at the conclusion of their initial procedure.

Results

Three patients developed massive neurological deficits with the drain in place; one patient had the drain removed at 24 hours and subsequently developed neurological symptoms during the following post-operative day. Significant risk factors for the development of hematoma were identified in two of the four patients. Average time to return to the operating room for hematoma evacuation was 6 hours (range 3–12 hours). Neurological status significantly improved in all four patients after hematoma evacuation.

Conclusions

Post-operative epidural hematoma causing catastrophic neurological deficit is a rare complication after spinal surgery. The presence of suction wound drains does not appear to prevent the occurrence of this devastating complication.     

Dorsal Epidural Intervertebral Disk Herniation With Atypical Radiographic Findings: Case Report and Literature Review

Abstract

Background/Objective: Intervertebral disk herniation is relatively common. Migration usually occurs in the ventral epidural space; rarely, disks migrate to the dorsal epidural space due to the natural anatomical barriers of the thecal sac.

Design: Case report.

Findings: A 49-year-old man presented with 1 week of severe back pain with bilateral radiculopathy to the lateral aspect of his lower extremities and weakness of the ankle dorsiflexors and toe extensors. Lumbar spine magnetic resonance imaging with gadolinium revealed a peripheral enhancing dorsal epidural lesion with severe compression of the thecal sac. Initial differential diagnosis included spontaneous hematoma, synovial cyst, and epidural abscess. Posterior lumbar decompression was performed; intraoperatively, the lesion was identified as a large herniated disk fragment.

Conclusions: Dorsal migration of a herniated intervertebral disk is rare and may be difficult to definitively diagnose preoperatively. Dorsal disk migration may present in a variety of clinical scenarios and, as in this case, may mimic other epidural lesions on magnetic resonance imaging.     

Review of Forty Years of Rehabilitation Issues in Spinal Cord Injury

Abstract

Context

Childhood laminectomy can lead to spinal deformity. This is a report of a case of paraplegia caused by rotokyphoscoliosis, a late complication of laminectomy.

Findings

A 55-year-old woman developed paraplegia due to post-laminectomy kyphoscoliosis. She had surgery for a spinal tumor at age 13 years. She developed kyphosis 2 years after the laminectomy, which has been gradually progressing over the years. She experienced weakness of lower limbs that progressed to paraplegia. There was no evidence for tumor recurrence. To our knowledge, this is the first reported case of post-laminectomy kyphoscoliosis causing late-onset paraplegia.

Conclusions/clinical relevance

This case highlights a possible long-term complication of laminectomy without stabilization or untreated kyphoscoliosis. Children should be followed closely after laminectomy because development of spinal deformity is very common. Without intervention, the kyphosis might progress and in the long term, serious neurological complications may result, including paraplegia.     

棘突劈开、单侧进入双侧减压与椎板切除减压治疗退变性腰椎管狭窄症的比较

目的 比较棘突劈开、单侧进入双侧减压与椎板切除、椎管减压治疗腰椎管狭窄症的疗效.方法 前瞻性研究2009年6月至2010年5月手术治疗56例退变性腰椎管狭窄症或椎管狭窄合并间盘突出患者资料.术前随机将患者分为棘突劈开、单侧进入双侧减压组(简称棘突劈开组)及传统腰椎椎板切除、椎管减压组(简称椎板切除组).棘突劈开组共27例,男15例,女12例;年龄49～71岁,平均59.4岁.椎板切除组29例,男18例,女11例;年龄52～69岁,平均61.1岁.术后第3天行血肌酸激酶测定.应用日本矫形外科学会(Japanese Orthopaedic Association,JOA)腰痛评分及疼痛视觉模拟评分(visual analogue scale,VAS)作为手术前后主、客观评分标准.术后6个月CT扫描评价棘突愈合情况.测量术前及末次随访时多裂肌MR面积.结果 棘突劈开组21例、椎板切除组24例获得2年以上有效随访.棘突劈开组术前腰痛及下肢痛VAS、JOA评分、多裂肌MR面积分别为:(5.6±1.7)分、(7.1±0.4)分、(11.6±2.6)分、(5.8±1.8)cm2;椎板切除组分别为(6.2±1.2)分、(7.9±1.3)分、(10.9±1.0)分、(6.1±2.0) cm2.棘突劈开组术后第3天血肌酸激酶测定值明显小于椎板切除组.棘突劈开组术后6个月随访时劈开棘突均完全愈合.末次随访时棘突劈开组下肢痛VAS、JOA评分及改善率分别与椎板切除组比较均无显著性差异.棘突劈开组腰痛VAS评分、多裂肌萎缩比分别为(1.0±0.5)分、6.4％±1.2％;椎板切除组分别为(2.6±0.7)分、l5.7％±3.0％,棘突劈开组均优于椎板切除组.两组动力位X线片均未见继发性腰椎不稳.结论 棘突劈开、单侧进入双侧减压可有效减少手术创伤及术后腰痛发生率,保护双侧多裂肌棘突止点及对侧多裂肌在椎板的附着点.     

Torsion biomechanics of the spine following lumbar laminectomy: a human cadaver study

Purpose

Lumbar laminectomy affects spinal stability in shear loading. However, the effects of laminectomy on torsion biomechanics are unknown. The purpose of this study was to investigate the effect of laminectomy on torsion stiffness and torsion strength of lumbar spinal segments following laminectomy and whether these biomechanical parameters are affected by disc degeneration and bone mineral density (BMD).

Methods

Ten human cadaveric lumbar spines were obtained (age 75.5, range 59–88). Disc degeneration (MRI) and BMD (DXA) were assessed. Disc degeneration was classified according to Pfirrmann and dichotomized in mild or severe. BMD was defined as high BMD (≥median BMD) or low BMD (<median BMD). Laminectomy was performed either on L2 (5×) or L4 (5×). Twenty motion segments (L2–L3 and L4–L5) were isolated. The effects of laminectomy, disc degeneration and BMD on torsion stiffness (TS) and torsion moments to failure (TMF) were studied.

Results

Load–displacement curves showed a typical bi-phasic pattern with an early torsion stiffness (ETS), late torsion stiffness (LTS) and a TMF. Following laminectomy, ETS decreased 34.1 % (p < 0.001), LTS decreased 30.1 % (p = 0.027) and TMF decreased 17.6 % (p = 0.041). Disc degeneration (p < 0.001) and its interaction with laminectomy (p < 0.031) did significantly affect ETS. In the mildly degenerated group, ETS decreased 19.7 % from 7.6 Nm/degree (6.4–8.4) to 6.1 Nm/degree (1.5–10.3) following laminectomy. In the severely degenerated group, ETS decreased 22.3 % from 12.1 Nm/degree (4.6–21.9) to 9.4 Nm/degree (5.6–14.3) following laminectomy. In segments with low BMD, TMF was 40.7 % (p < 0.001) lower than segments with high BMD [34.9 Nm (range 23.7–51.2) versus 58.9 Nm (range 43.8–79.2)].

Conclusions

Laminectomy affects both torsion stiffness and torsion load to failure. In addition, torsional strength is strongly affected by BMD whereas disc degeneration affects torsional stiffness. Assessment of disc degeneration and BMD pre-operatively improves the understanding of the biomechanical effects of a lumbar laminectomy.