Cervical congenital spondylolytic spondylolisthesis associated with duplication of the vertebral artery: case report

Background contextCervical bilateral congenital spondylolysis with spondylolisthesis is an abnormality both of congenital and mechanical origin, characterized by its primary feature, cervical bilateral spondylolysis. We are unaware of any reports describing cervical congenital spondylolytic spondylolisthesis associated with duplication of the vertebral artery.PurposeTo report the case of a patient affected with cervical bilateral congenital spondylolysis with spondylolisthesis associated with duplication of the vertebral artery.Study designA unique case report from a university hospital and a literature review.Patient sampleAn 18-year-old man who arrived at the emergency department complaining of neck pain starting from a car accident 5 days ago.MethodsNeurologic examination and images taken by ordinary radiographs, magnetic resonance imaging (MRI) scans, ordinary computed tomography (CT) scans, and CT angiograms with three-dimensional (3D) reconstruction.ResultsNeurologic examination did not find evidence of strength deficit in upper extremities. Ordinary radiographs of the cervical spine showed spondylolisthesis of C6 and C7 and a cortical cleft between the superior and inferior articular facets of the C6 vertebra and spina bifida of the C6 and C2 vertebrae and an abnormal appearance of the remnant spinous processes of the cervical vertebrae. Magnetic resonance imaging confirmed the abnormalities that had been noted on the radiographs. Computed tomography scans of the cervical spine showed congenital spondylolytic spondylolisthesis and spina bifida of the C6 vertebra and duplication of the vertebral artery. They also showed double origins of the vertebral artery depicted by 3D angiographic reconstruction. Conservative treatment of wearing a cervical collar and receiving muscle relaxants and anti-inflammatory drugs was effective. With the pain completely subsided, the patient was discharged 5 days after arriving at the emergency department.ConclusionsVascular abnormalities should be suspected and investigated in cases of congenital spondylolysis or spondylolytic spondylolisthesis. We strongly suggest performing angio-CT or angio-MRI and 3D reconstruction in these cases. Awareness of the presence of a duplicated vertebral artery and the course of its limbs could significantly help planning in cases proceeding to surgery.     

Bilateral cervical spondylolysis of C7

Background context

Cervical spondylolysis, which is defined as a cleft between the superior and inferior articular facets of the articular pillar, is a rare condition. The sixth cervical vertebra (C6) is the level most commonly affected. Cases involving C2, C3, C4, or C5 have also been reported. However, to date, no case of C7 spondylolysis has been reported.

Purpose

To present a rare case of bilateral spondylolysis of the seventh cervical vertebra (C7) in a 58-year-old man.

Study design

A case report.

Methods

A 58-year-old man visited our hospital with chronic posterior neck pain radiating to the left upper extremity. Magnetic resonance imaging (MRI) study revealed left foraminal disc herniations at C5–C6 and C6–C7. Cervical spondylolysis involving C7 was discovered incidentally during computed tomography (CT)–guided transforaminal steroid injection. Plain radiographs, CT images, and MRIs were reviewed thoroughly once again.

Results

The patient’s symptoms were relieved after he received CT-guided transforaminal steroid injections. Plain radiographs revealed a radiolucent defect in the articular pillar and cleft at the spinous process of C7. Computed tomography confirmed bilateral spondylolysis and spina bifida occulta of the C7 vertebra. Magnetic resonance imaging revealed absence of edema, which was suggestive of a chronic lesion.

Conclusion

Involvement of C7 is not exceptional in a case of cervical spondylolysis.     

单侧枢椎椎板螺钉在椎动脉变异的上颈椎不稳中的临床应用

目的：探讨后路寰椎侧块螺钉联合单侧枢椎椎板螺钉＋对侧枢椎椎弓根螺钉固定、自体双皮质骨加压植骨融合术治疗上颈椎不稳伴椎动脉变异的临床疗效。方法：2008年6月至2012年12月,行后路寰椎侧块螺钉联合单侧枢椎椎板螺钉＋对侧枢椎椎弓根螺钉固定、自体双皮质骨加压植骨融合术12例,男8例,女4例,年龄16—77岁,平均47．5岁。术前患者枕颈部活动受限伴或不伴疼痛,VAS评分0-7分,平均3．50±2．71;椎动脉造影或颈椎CTA示单侧椎动脉明显狭窄。观察术中有无神经及血管损伤;术后7d内行X线和CT检查,了解内固定位置;术后随访观察有无内固定松动、断裂失败并发症、复位丢失,以及植骨融合率等。结果：12例单侧枢椎椎板螺钉固定,术中未发生神经和椎动脉损伤。患者颈部VAS评分0．92±0．90,较术前明显减轻（P=0．01）。术后x线示12例患者颈椎序列恢复良好,CT示1例枢椎椎板腹侧皮质侵犯,余位置均良好。12例患者均获得随访,时间6个月～3年;未见内固定松动、断裂和复位丢失等并发症;术后6个月12例均骨性融合。结论：后路寰椎侧块螺钉联合单侧枢椎椎板螺钉＋对侧枢椎椎弓根螺钉固定、自体双皮质骨加压植骨融合术,既避免了传统螺钉固定椎动脉损伤的同时,又克服了部分病例双侧枢椎椎板螺钉时植骨床的不足,在保证良好力学稳定的情况下,可以取得良好的骨性融合率。单侧枢椎椎板螺钉可以作为一种安全有效的补充固定措施应用于椎动脉变异的上颈椎不稳患者中。     

数字化“定点-定向”双导航模板辅助椎弓根螺钉置钉治疗寰枢椎不稳

目的评价数字化"定点-定向"双导航模板辅助椎弓根螺钉置钉治疗寰枢椎不稳的临床效果。方法回顾性分析2013年9月—2016年12月收治的24例采用数字化"定点-定向"双导航模板辅助行颈椎后路椎弓根螺钉置钉的寰枢椎不稳患者的临床资料。术前CT扫描获取数据经Mimics 10.0软件三维重建后进行寰枢椎后路椎弓根螺钉置钉理想钉道的计算机辅助规划,并根据寰枢椎后方骨性结构表面数据设计个性化"定点-定向"双导航模板。在3D打印机上制作"定点-定向"双导航模板,高温消毒后应用于临床手术辅助置钉。术后根据颈椎X线和CT检查结果评价椎弓根螺钉的位置,并观察植骨融合情况及颈椎稳定性。采用颈部和/或枕骨下疼痛视觉模拟量表(VAS)评分评估患者的临床疗效。结果应用数字化双导航模板为24例患者置入椎弓根螺钉,22例行寰枢椎后路椎弓根螺钉固定,2例行寰枢椎后路椎弓根螺钉并椎板螺钉固定。共置入寰椎椎弓根螺钉48枚,枢椎椎弓根螺钉46枚,枢椎椎板螺钉2枚。术后CT检查示所有螺钉均未穿破钉道骨皮质。所有患者随访6个月,大部分患者颈部疼痛明显缓解,VAS评分由术前(7.78±1.12)分降至术后(2.48±0.55)分,差异有统计学意义(P0.05)。术前肌力下降者术后均不同程度恢复。所有患者均未发生神经、血管损伤等置钉相关并发症。结论数字化"定点-定向"双导航模板不仅能够提高手术置钉的准确性和安全性,还能针对不同类型的寰枢椎不稳提供更合理的置钉方式。     

Case Report: Absent C6 Cervical Pedicle in a Collegiate Football Player

Congenital absence of a cervical pedicle is a rare clinical finding with only 70 reported cases in the literature from 1946 until present. The congenitally absent pedicle has clinical importance owing to the frequency of misdiagnosis and inappropriate invasive treatments. We present the case of a 21-year-old college football player who experienced neck and shoulder pain after violent twisting of his neck by the face mask. The player walked off the field under his own power. He was sent to the locker room, where he underwent right shoulder and cervical spine radiographs. Initial review of the radiographs raised concern for a jumped right C6 facet. The patient then underwent CT and MRI of the cervical spine, confirming the diagnosis of an absent cervical pedicle. He was treated nonoperatively for a short time and completed the season. He had no symptoms at last followup at 8 months. The most frequent location of the absent cervical pedicle is at the C6 level, and the next most common is at the C5 level. Neural compression or instability is uncommon and nonsurgical treatment is the mainstay of treatment. Misdiagnosis can lead to inappropriate treatment such as halo or tong application with traction, which occurred in seven of 57 cases in one series, and exploratory surgery, which occurred in four of 57 cases.     

正中旁入路钉钩系统固定直接修补青少年腰椎弓峡部裂

目的：观察应用椎弓根钉-椎板钩系统内固定治疗青少年腰椎峡部裂的临床疗效。方法：自2003年8月至2008年12月应用钉钩系统加压固定结合自体髂骨植骨融合治疗28例腰椎峡部裂患者（男13例,女15例;年龄15～26岁,平均21.6岁）,包括L3、L4崩裂3例,L4、L5崩裂5例,L4崩裂8例,L5崩裂12例。患者术前均腰痛且持续6个月以上。根据手术前后的X线、CT检查和Macnab评分标准,评定该术式的融合率及临床效果。结果：28例均获随访,时间9～24个月,平均14.9个月,经X线及CT检查,28例椎弓根峡部均获得骨性融合。根据Macnab评分标准：优22例,良5例,可1例。结论：采用钉钩系统固定直接修补青少年腰椎弓根峡部裂缩短了手术时间,减少了出血,尽可能多地保留了脊柱后部结构,避免了医源性的脊柱失稳,术后椎节即刻获得稳定并保留了病椎相邻椎间盘的活动度,取得了满意的临床疗效。     

寰枢椎椎弓根钉治疗寰枢椎脱位的临床应用

目的：探讨经后路寰枢椎椎弓根钉固定系统复位固定植骨融合治疗寰枢椎脱位的临床疗效。方法：2005年12月至2007年6月收治16例寰枢椎脱位的患者,男10例,女6例;年龄38～45岁,平均40.5岁;其中12例伴有神经损伤,按ASIA分级：B级3例,C级5例,D级4例。术前均行寰枢椎CT扫描及X线检查,入院后立即行颅骨牵引。术中应用经后路通用脊柱椎弓根钉棒矫形固定系统固定,同时在寰椎后弓和枢椎椎板间大量髂骨植骨融合。观察术后近期疗效及并发症情况。结果：术中未发生血管、神经等重要组织结构的损伤。16例患者均获得随访,随访时间12～24个月,平均18个月。术后所有患者头枕部疼痛、酸困不适症状均得到改善,采用Odom临床疗效评定标准,优12例,良4例。12例伴有神经损伤患者11例得到明显恢复。按ASIA分级：B级1例,C级2例,D级5例,E级4例。无内固定物松动及断裂,所有植骨均达骨性融合。结论：经后路寰枢椎椎弓根钉固定系统复位固定植骨融合能够直视下置钉、短节段固定、术中复位,且固定可靠,融合率高,有利于上颈椎稳定性重建及脊髓神经功能恢复。     

Cervical spondylolysis in a judo player: a case report and biomechanical analysis

Study design  A case report and a biomechanical study using a finite element method. Objectives  To report a case with the cervical spondylolysis and to understand the biomechanics of the cervical spine with spondylolysis at C6. Summary of background data  Cervical spondylolysis, although not a common spinal disorder, can occur in athletes. Presently, the exact pathology, natural history and biomechanics are not known. Thus, treatment strategies for this disorder in athletes are in controversy. To treat and/or advise patients with cervical spondylolysis, the cervical spine biomechanics regarding this disorder should be understood. Methods  A case of a 12-year-old male judo player is presented. The patient presented with occipital and upper neck pain. Plain radiographs, reconstructed CT scan and MRIs of this patient were reviewed. Biomechanically, stress distributions were analyzed in response to 73.6 N axial compression and 1.5-Nm moment in flexion, extension, lateral bending, and axial rotation using a FE model of the intact ligamentous C3 to C7 segment. Bilateral spondylolysis was created in the model at C6. The stress results from the bilateral defect model were compared to the intact model predictions. Results  Plain radiographs showed bilateral C6 spondylolysis, and grade I spondylolisthesis. MRI showed mild disc degeneration at C6/7. With conservative treatment, the symptoms disappeared. In the spondylolysis model, the maximum Von Mises Stresses at C6/7 increased in all cervical spine motions, as compared to the intact case. Specifically, in axial rotation, the stress increase was 3.7-fold as compared to the intact model. The range of motion at C6/7 increased in the spondylolysis model as well. Again, during axial rotation, the increase in motion was 2.3-fold when compared to the intact model. Conclusions  Cervical spondylolysis can cause biomechanical alterations, especially in axial rotation, leading to increased disc stresses and range of motion. The increased stresses in the disc and the hypermobility would be a dangerous condition for athletes participating in contact sports such as judo. Thus, we recommended that judo players with cervical spondylolysis should change to non-contact sports, such as jogging.     

钉棒系统固定结合峡部植骨融合治疗青少年腰椎峡部裂远期疗效

目的：探讨腰椎后路椎弓根钉固定结合峡部植骨融合治疗青年腰椎峡部裂远期疗效。

方法：回顾性分析自2006年1月至2014年7月收治16例采用腰椎后路椎弓根钉固定结合峡部植骨融合术治疗的单纯腰椎峡部裂不伴有腰椎滑脱的青年患者,其中男11例,女5例;年龄18~21岁,平均19.3岁;病程12~26个月,平均22个月。所有患者存在活动后腰部疼痛,严重者下床活动困难,术前CT证实L₅峡部裂12例,L₄峡部裂4例,并在术后影像学证实植骨融合后取出内固定。采用腰痛视觉模拟评分法对术前、术后各时间点进行评分,采用腰椎CT检查评估腰椎峡部融合情况,采用腰椎MRI检查评估固定节段及邻近节段腰椎间盘退变情况。

结果：本组16例患者,13例26侧获得完整随访,平均96个月;手术时间80~105 min,平均95 min;术中出血量150~300 ml,平均225 ml。所有患者手术顺利完成,无手术相关并发症发生;患者术后各时间点VAS评分较术前改善（P<0.01）。术后腰椎CT检查均获骨性融合,融合时间6~14个月,平均12个月;腰椎MRI检查无邻近节段退变及固定节段间盘变性、突出等改变,术后远期无症状复发及再发峡部裂。

结论：采用腰椎后路椎弓根钉固定结合峡部植骨融合治疗青年腰椎峡部裂,该术式安全、有效,融合率高,减少对正常生理活动范围的干扰,长期疗效满意。     

椎孔外颈神经卡压综合征与颈椎病的鉴别

目的分析曾被误诊为颈椎病的椎孔外颈神经卡压的原因及鉴别该两疾病的方法。方法分析44例曾被误诊为颈椎病的椎孔外颈神经卡压征后发现(1)颈椎病多见壮年、老年人。以颈肩部酸痛,颈部活动到一个角度时特别痛,头颈不知放何处好为主要症状。体征为棘突间有压痛、两项部或颈外侧有压痛,仅有1～2根神经根支配区的感觉障碍,前臂后上方内侧偶有感觉障碍。颈部痛点局封后无效。(2)椎孔外神经根卡压征老、壮、青、少年均可发生。以颈肩部不适,肢体麻痛,患侧上肢不知放何处好为主要症状。颈部胸锁乳突肌后缘中点有明显压痛点。背部压痛点在脊柱旁并向患侧放射。常见C1至T1多神经支配区的感觉障碍,并常可合并前臂后上方内侧、面部感觉障碍。颈部痛点局封立即见效,感觉改善、肌力增加。结果诊断性治疗即颈部痛点局封,是鉴别椎孔外神经根卡压征和颈椎病的重要方法。结论椎孔内外颈神经根卡压征常和颈椎病相混淆,故对其进行鉴别诊断是非常重要的。     

后路减压固定治疗伴椎间盘突出的下颈椎骨折脱位

目的 探讨经后路减压复位椎弓根螺钉固定治疗伴椎间盘突出的下颈椎骨折脱位的疗效。方法 对2009年6月至2012年9月采用经后路减压复位椎弓根螺钉固定治疗伴椎间盘突出的下颈椎骨折脱位18例病例进行回顾性分析。结果 所有手术均顺利完成,共置入椎弓根螺钉88枚,平均手术时间为2.7 h,平均出血量为400 mL。所有患者均未因神经功能恶化或椎间盘突出而需要再次行前路手术。18例患者术后平均随访15个月。复查X线片、CT片示骨折脱位复位良好,椎间隙高度及颈椎生理弧度得到恢复。末次随访时,除10例Frankel A级患者以外,其余患者Frankel分级提高1～2级。结论 经后路减压复位椎弓根螺钉固定可适用于伴椎间盘突出的下颈椎骨折脱位,后路手术有利于复位,椎弓根螺钉技术具有良好的生物力学稳定性,能有效地恢复和维持颈椎的序列,同时避免了前路手术。     

Surgically treated cervical myelopathy: a functional outcome comparison study between multilevel anterior cervical decompression fusion with instrumentation and posterior laminoplasty

Background contextMultilevel cervical myelopathy can be treated with anterior cervical discectomy and fusion (ACDF) or corpectomy via the anterior approach and laminoplasty via the posterior approach. Till date, there is no proven superior approach.PurposeTo elucidate any potential advantage of one approach over the other with regard to clinical midterm outcomes in this study.Study designA prospective, 2-year follow-up of patients with cervical myelopathy treated with multilevel anterior cervical decompression fusion and plating and posterior laminoplasty.Patient sampleIn total, 116 patients were studied. Sixty-four patients underwent ACDF two levels and above or anterior cervical corpectomy and fusion one level and above. Fifty-two patients underwent posterior cervical surgery (laminoplasty C3–C6 and C3–C7).Outcome measuresSelf-report measures: Japan Orthopedic Association (JOA) score, JOA recovery rate, visual analog scale for neck pain (VASNP), neck disability index (NDI), and American Academy of Orthopaedic Surgeons (AAOS) neurogenic symptom score (AAOS-NSS). Physiologic measures: range of motion (ROM) flexion and extension of neck. Functional measures: short-form 36 (SF-36) score comprising physical functioning, physical role function, bodily pain, general health, vitality, social role function, emotional role function, and mental health scales.MethodsComparison of the JOA scores, JOA recovery rates, NDI scores, SF-36 scores, VASNP, and ROM preoperatively to 2 years. Chi-square and two-sided Student t tests were used to analyze the variables.ResultsPosterior surgery took an hour shorter (p<.05) and had better improvement in JOA scores at early follow-up of 6 months (p=.025). Anterior surgery group had better improvement of NDI scores at early follow-up of 6 months (p=.024) and was associated with less blood loss intraoperatively compared with posterior surgery. There was no statistical difference between the two groups for JOA scores, JOA recovery rates, SF-36 quality-of-life scores, NDI, AAOS-NSS, VAS neck pain, and ROM at 2 years. Complications were higher for anterior surgery group: two hematoma postoperation, one vocal cord paresis, and one new onset C6/C7 dermatome numbness versus one dura leak in posterior surgery group.ConclusionsOur study showed that patients with multilevel disease treated with laminoplasty do well and compare favorably with patients treated with an anterior approach. Notably, posterior surgery was associated with shorter operating time, better improvement in JOA scores at 6 months, and a tendency toward lesser complications. Posterior surgery was not associated with increased neck disability and neck pain at 2 years. Anterior surgery had better NDI improvement at early follow-up. There is a need for a larger study that is prospectively randomized with long-term follow-up before we can confidently advocate one approach over the other in the management of cervical myelopathy.     

Cervical spondylolysis in a child: a case with hypermobility

Background contextCervical spondylolysis (CS) is a rare disorder involving a cleft in the articular mass, at the junction of the superior and inferior facet joints, and often a complex malformation of the posterior elements of the vertebra. The most commonly affected level is the sixth cervical vertebra. Most of the cases are adults. Its origin, mechanical or embryological, is controversial.PurposeTo report the case in a young boy and to outline the imaging findings related to the causal mechanism.Study designA case report.Patient sampleA 7-year-old boy with CS of the sixth cervical vertebra discovered after a minimal trauma.MethodsRadiological observation and literature review.ResultsA forward listhesis in extension is observed despite an intact disc on magnetic resonance imaging, expressing the loads applied to the dysplastic vertebra before the mechanical failure of the vertebral structures occurs.ConclusionsA mixed origin, both mechanical and congenital is suggested. It is proposed that the CS results from microimpacts because of the cervical spine biomechanics affecting a posterior arch prone to develop a cleft as a result of associated malformations.     

枢椎椎板螺钉在上颈椎后路固定术中的应用

目的探讨枢椎椎板螺钉固定术应用于上颈椎后路融合内固定术中的可行性。方法回顾性分析本院2012年1月—2014年12月在上颈椎后路融合固定术中采用枢椎椎板螺钉固定的19例患者资料,术中根据枢椎椎弓根是否存在缺如、细小等情况,选择置入双侧枢椎椎板螺钉或单侧枢椎椎板螺钉并对侧椎弓根螺钉,联合枕骨板螺钉和/或寰椎侧块螺钉。15例上颈椎畸形患者均有不同程度脊髓功能损害表现,日本骨科学会(JOA)评分为5~15分,平均11.5分。4例外伤性寰枢椎骨折患者有后颈部疼痛及活动障碍,疼痛视觉模拟量表(VAS)评分为2~7分,平均4.5分。术后复查患者影像学资料,观察内固定位置及植骨融合情况。结果所有手术顺利完成,未发生椎动脉、脊髓等损伤。术后复查CT,显示所有枢椎椎板螺钉位置良好,均未突破内侧皮质骨。随访时X线、CT示螺钉位置良好,无松动及断钉。所有患者术后12个月植骨均融合,上颈椎畸形患者神经功能均有不同程度改善,JOA评分为13~17分,平均15.3分。外伤性寰枢椎骨折患者颈部疼痛及活动障碍明显改善,VAS评分为0~2分,平均1.0分。结论枢椎椎板螺钉固定在上颈椎后路固定手术中方法简单安全、效果良好,对于无法行枢椎椎弓根螺钉固定的患者,枢椎椎板螺钉固定是一种安全有效的替代方法。     

经伤椎椎弓根植骨联合后路椎弓根内固定治疗胸腰椎稳定型爆裂性骨折

目的探讨经骨折椎椎弓根植骨联合椎弓根内固定治疗胸腰椎稳定型爆裂性骨折的方法和效果。方法对17例胸腰椎稳定型爆裂性骨折的患者行经骨折椎椎弓根植骨及椎弓根内固定术,术前、术后及随访时测量椎体高度、后凸角,了解神经功能改变及腰背疼痛变化。结果随访8～37个月,无断钉及内固定物松动,椎体高度和后凸角无明显再丢失,神经功能及腰背疼痛明显改善。结论经骨折椎椎弓根植骨联合后路椎弓根内固定治疗胸腰椎稳定型爆裂性骨折可重建脊柱前中柱的稳定性,防止后期矫正角度及椎体高度的再丢失。     

Direct repair of multiple levels lumbar spondylolysis by pedicle screw laminar hook and bone grafting: clinical, CT, and MRI-assessed study

INTRODUCTION: A prospective analysis of 6 cases with multiple-level spondylolysis treated by direct repair with pedicle screw laminar hook is presented. The objective of the study was to evaluate the clinical outcome, plain radiographs, computed tomography (CT) scan, and magnetic resonance imaging to demonstrate the result of direct repair in the treatment of multiple-level spondylolysis. MATERIALS AND METHODS: Ten patients with multiple-level spondylolysis of lumbar spine were treated with segmental pedicle screw hook fixation and autogenous bone graft. Four patients had lost follow-up. Six patients were followed up for a minimum of 2 years (mean 34.3 mo, range 24 to 55 mo). Patient's average age was 22 years old (range from 20 to 25 y old). All lytic defects were bilateral and located at 2 different lumbar vertebras (levels). CT scans and MR images were obtained at the latest follow-up postoperatively to assess the healing of the bony defects and the adjacent disc conditions. Fusion was considered to be presented when trabecula across the lytic defect was detected. RESULTS: The union rate was 87% (21 pars/24 pars) on plain radiographs and 75% (18 pars/24 pars) on CT scans. Follow-up magnetic resonance imaging of lumbar spine showed no disc degeneration. All patients were satisfied (either excellent or good) with the postoperative outcomes. CONCLUSIONS: Direct repair of multiple-level spondylolysis by pedicle screw laminar hook and autogenous bone graft would be the alternative of treating patients with persistent back pain after 6 months of conservative treatment The favorable clinical outcome was correlated with bony healing rate in this series.     

椎板后壁部分刮除辅助透视行颈椎弓根钻孔

目的探索椎板后壁部分刮除辅助透视行下颈椎椎弓根钻孔的可行性。方法3具新鲜尸体下颈椎的30例椎弓根，透视确定椎弓根轴线所在高度，将此高度侧块与椎板后壁交界内外侧各5mm范围内的皮质骨去除，刮除其下松质骨，先暴露出内侧的椎板前壁，后紧贴椎板前壁向外侧刮除，找到椎弓根入口。根据内倾角确定入口外侧骨质去除范围，以椎弓根内壁为参照，透视确定上倾角，行髓腔钻孔。CT扫描明确钻孔准确性。结果1例髓腔消失，放弃钻孔；27例钻孔准确；2例髓腔〈3mm，椎弓根外壁向外侧移位，但〈2mm。结论椎板后壁部分刮除辅助透视行下颈椎椎弓根髓腔钻孔效果满意。     

Progressively Unstable C2 Spondylolysis Requiring Spinal Fusion: Case Report

Cervical spondylolysis is a rare condition defined as a corticated cleft at the pars interarticularis in the cervical spine. This is the case of C2 spondylolysis demonstrating progressive significant instability, which was successfully treated by anterior cervical discectomy and fusion (ACDF) with cervical anterior plate. We describe a 20-year-old female with C2 spondylolysis presenting with progressive worsening of neck pain associated with progressive instability at the C2/3 segment. The progression of instability was well-documented on flexion-extension cervical spine x-rays. She was successfully treated by C2/3 ACDF with anterior cervical plate. Her preoperative significant neck pain resolved immediately after the surgical intervention. She was completely free from neurological symptoms at 1-year postoperative follow-up. We also review the literature and discuss 24 reported cases with C2 spondylolysis. When planning treatment, we should make sure to differentiate this pathology from acute traumatic fracture, which is a hangman''s fracture. Assessment of C2/3 instability associated with neurological deficits is extremely important to consider management properly. C2/3 ACDF with cervical plate is biomechanically viable, less invasive, and provides adequate surgical stabilization for unstable C2 spondylolysis.     

Contralateral spondylolysis and fracture of the lumbar pedicle in an elite female gymnast: a case report

STUDY DESIGN: The case of an elite female gymnast whose pathology started in her 12th year and whose evolution has been exceptional is reported. OBJECTIVE: To present a fracture of the right lumbar pedicle showing complete spontaneous consolidation despite gymnastic practice 15 hours a week. SUMMARY OF BACKGROUND DATA: Lumbar pain, which has an incidence of approximately 75% among young athletes, often results from diseases of the posterior arch of vertebrae in gymnasts, including spondylolysis. The association between unilateral spondylolysis and fracture of the contralateral lumbar pedicle in young athletes is poorly described. METHODS: An elite young female gymnast underwent clinical examination and lumbar radiographs (as systematically required by the French Federation for high-level gymnasts) from 1994 to 1997 to join a sports program in gymnastics. RESULTS: Clinical examination and lumbar radiographs systematically required of an asymptomatic female gymnast allowed the condensation of the right pedicle to be observed before lysis of the left isthmus of L5 in 1994, unilateral lysis of the left isthmus of L5 in 1995, a right pedicular fracture of L5 in 1996, and healing of the pedicular fracture in 1997. CONCLUSION: Inconsistency between radiographs and clinical observations can be noted, and spontaneous consolidation of pedicular fractures can occur despite the practice of the gymnastics 15 hours a week.