目的 比较胸腰椎骨折内固定手术中机器人辅助(robot-assisted,RA)与徒手(free-hand,FH)置入椎弓根螺钉的精度及手术即时效果.方法 采用前瞻性研究,选择我院2015年5月～2020年1月146例椎弓根内固定术,其中65例选择RA螺钉置入(RA组),81例选择FH螺钉置入(FH组).根据Gertzbein与Robbins量表评价椎弓根螺钉置入的准确性,对2组螺钉置入准确性和围手术期指标包括手术时间、术中出血量、疼痛视觉模拟评分(Visual Analogue Scale,VAS)、骨折节段Cobb角、椎体前缘相对高度和是否翻修等进行比较.结果 RA组置入331枚螺钉,其中325枚螺钉A级,5枚B级,1枚C级;FH组置入484枚螺钉,其中431枚螺钉A级,44枚B级,9枚C级.RA组螺钉位置优秀(A级)率明显高于FH组[98.2％(325/331)vs.89.0％(431/484),χ2=24.442,P=0.000].FH组475枚螺钉(98.1％)的位置在临床上是可接受的(A+B级),RA组为330枚(99.7％).RA组手术时间(119.8±38.9)min,显著多于FH组(92.6±25.0)min(t=4.822,P=0.000);术中出血量中位数50.0(25.0,100.0)ml,显著少于FH组100.0(100.0,200.0)ml(Z=-6.261,P=0.000).2组内术后1 d疼痛VAS评分中位数较术前明显降低[RA组:3.0(3.0,3.5)分vs.6.0(6.0,7.0)分,Z=-7.066,P=0.000;FH组:3.0(3.0,4.0)分vs.6.0(6.0,7.0)分,Z=-7.939,P=0.000],但2组间比较差异无显著性(P>0.05).2组内骨折节段Cobb角术后3～5 d较术前明显改善[RA组:9.4° ±3.3°vs.20.3° ±3.8°,t=23.173,P=0.000;FH组:9.7° ±3.4°vs.20.0° ±3.8°,t=23.407,P=0.000],但2组间比较差异无显著性(P>0.05).2组内骨折椎体前缘相对高度出院前较术前明显改善[RA组:(89.2±4.6)％vs.(63.6±4.6)％,t=-174.651,P=0.000;FH组:(89.4±4.9)％vs.(64.1±5.2)％,t=-169.251,P=0.000],但2组间比较差异无显著性(P>0.05).2组患者均未出现手术并发症、术式变更或因手术并发症造成的术后翻修.结论 胸腰椎骨折椎弓根螺钉内固定术中,RA置钉是准确和安全的.

背景:颈椎后纵韧带骨化症(OPLL)在亚洲高发,连续型或混合型OPLL常采用颈椎后路椎板成形术治疗.此类病例中有骨化灶侵及C2或C2以上水平造成脊髓压迫的情况,需进行手术减压.但同时可能破坏颈半棘肌和头半棘肌的肌肉附着点,造成颈椎前凸丢失和术后轴性疼痛.目的:观察保留或重建棘突肌肉附着点的C2椎板穹窿状减压联合棘突纵割式椎板成形术(SLAC)治疗高位颈椎OPLL的临床及影像学疗效.方法:采用回顾性病例系列研究的方法,选取2017年1月至2018年12月在我院因颈椎后纵韧带骨化症且骨化灶压迫侵及C2/3椎间盘水平及以上的手术患者,对该组患者行C2椎板穹隆状减压联合SLAC术.对比术前及末次随访的颈椎JOA评分、颈椎功能障碍指数(NDI)、颈肩痛视觉模拟评分(VAS)、颈椎前凸角等指标,并记录并发症情况.部分患者行术后CT,测量脊髓容纳空间(SAC),并与术前对比,评价影像学效果.结果:共27例患者纳入本研究,其中男21例,女6例,年龄40～81岁,平均(63.9±8.3)岁.随访时间6～20个月,平均(12.9±4.0)个月.与术前比较,末次随访时颈椎JOA评分显著增加(10.8±1.2vs 12.9±1.7,P=0.001),NDI(26.3±6.2 vs 14.4±5.9,P＜0.001)、颈椎前凸角(11.6°±6.9° vs 8.3°±6.2°,P=0.004)显著降低,差异均有统计学意义;但颈肩痛VAS评分(2.4±1.0 vs 2.9±1.3,P=0.131)差异无统计学意义.13例患者术后即刻行CT扫描,手术前后C2水平SAC差异有统计学意义[(6.1±1.9)mm vs (15.3±2.5)mm,P＜0.001].结论:保留或重建棘突肌肉附着点的C2椎板穹窿状减压联合棘突纵割式椎板成形术的临床及影像学结果满意,并不增加术后颈肩部轴性疼痛,可作为治疗高位颈椎后纵韧带骨化症的手术选择.

目的 探讨骨科机器人辅助技术在颈前路齿状突螺钉内固定手术中的安全性. 方法 2017年11月～2018年8月对9例Ⅱ型齿状突骨折全麻下行齿状突骨折复位,术中三维CT扫描,齿状突螺钉路径规划,骨科机器人引导齿状突螺钉导针植入,齿状突空心螺钉固定. 结果 平均手术时间178.3 min(120～240 min),平均术中估计出血量36.7 ml(20～50ml),术后平均住院时间4.3 d(3～5 d).共置入齿状突螺钉10枚,根据Neo评级量表,10枚螺钉均为0级.所有患者均未发生围手术期并发症.术后3个月随访,所有患者骨折愈合情况良好,无明显骨折不愈合或硬化带形成.Smiley-Webster量表7例优,2例良. 结论 骨科机器人辅助颈椎前路齿状突螺钉内固定术安全、有效,可以作为Ⅱ型齿状突骨折的手术方法.

目的 比较经椎间孔腰椎椎间融合术(transforaminal lumbar interbody fusion,TLIF)中机器人辅助(robot-assisted,RA)与徒手(free-hand,FH)置入椎弓根螺钉的准确性和安全性.方法 采用前瞻性队列研究的方法,共纳入2016年6月 ～2018年6月TLIF手术116例,由患者选择手术方式,其中RA 57例,FH 59例.比较置钉准确性和围手术期相关指标.根据Gertzbein-Robbins量表和小关节侵犯,评价椎弓根螺钉置入的准确性.围手术期相关指标主要包括手术时间、术中出血量、辐射暴露和是否翻修等.结果 在RA组234枚螺钉中,A级220枚,B级10枚,C级3枚,D级1枚;在FH组的278枚螺钉中,A级244枚,B级20枚,C级10枚,D级2枚,E级2枚.RA组螺钉位置优秀(A级)率高于FH组[94.0％(220/234)vs.87.8％(244/278),χ2=5.837,P=0.016].RA组螺钉的临床可接受(A+B级)率高于FH组[98.3％(230/234)vs.95.0％(264/278),χ2=4.145,P=0.042].RA组螺钉侵犯近端小关节更少[1.7％(4/234)vs.6.5％(18/278),χ2=7.016,P=0.008].RA组辐射剂量更低[(33.3±24.4)μSv vs.(56.8±30.9)μSv,t=-4.563,P=0.000].FH组2枚螺钉需要二次手术翻修,RA组无螺钉需要翻修(P=0.503).结论 与徒手置钉相比,骨科机器人辅助TLIF腰椎置钉具有更高的准确性和安全性.

BACKGROUND:Robotic techniques are beginning to be applied to spine surgery, but safety is always a concern. Respiration-induced motion during surgery could lead to inaccurate robot-assisted pedicle screw placement. Accurate positional information for vertebral movement is needed to develop new techniques to eliminate or adjust respiration-induced motion and improve the accuracy of robotic spine surgery.METHODS:An optical tracking system was attached to patients' backs to track the motion of the C3, C7, T7, T12, L4 and S1 vertebral bodies. Monitoring was done in the operating room, with patients under general anaesthesia.RESULTS:Measured motion (peak to peak) during breathing was greater in T7 (2.2593 mm), T12 (2.2665 mm) and L4 (1.6054 mm) than in other segments. Anterior-posterior motion was greater than either left-right or superior-inferior motion.CONCLUSION:During general anaesthesia, significant motion occurs in vertebral bodies, caused by breathing, especially in the lower thoracic and lumbar segments. Copyright © 2015 John Wiley & Sons, Ltd.

The purpose of this study was to assess the efficacy and accuracy of posterior screw fixation for unstable Hangman’s fracture using intraoperative 3D fluoroscopy-based navigation.

OBJECTIVE: This prospective randomized controlled study compared the efficacy and safety of two paraspinal muscle-sparing surgical approaches for the management of neurologically intact patients with thoracolumbar burst fractures and posterior ligamentous complex injuries. METHODS: Patients were randomized to undergo either percutaneous (n = 31) or paraspinal (n = 30) fluoroscopically-guided pedicle screw—rod fixation, and were followed for ≥ 3 years. Preoperative postural reduction was attempted in all patients. RESULTS: The percutaneous approach was associated with significantly less intraoperative blood loss and shorter duration of surgery and hospitalization, as well as less pain and better functional recovery at 3 months after surgery compared with the paraspinal approach. Paraspinal surgery resulted in significantly better correction of kyphosis and restoration of vertebral height compared with percutaneous surgery. There were no differences in long-term clinical outcomes between the two groups. CONCLUSIONS: The minimally invasive percutaneous approach appears to be better in cases of successful postural reduction. The paraspinal approach results in better surgical correction and is, therefore, recommended for patients without successful postural reduction.

OBJECTIVE:To evaluate the clinical therapeutic outcomes for severe burst fracture of lumbar vertebrae via a posterior approach for one-stage spinal "three-column" reconstruction.METHODS:An retrospective analysis of data was performed for 21 patients with severe burst fracture of lumbar vertebrae undergoing a posterior approach for one-stage spinal "three-column" reconstruction from 2005 to 2010. It was compared with previous 15 cases undergoing a staged anteroposterior approach. The operative duration, volume of blood loss, pre- and post-operative imaging measurements of kyphosis and vertebral height and nerve function recovery were evaluated.RESULTS:The values of operative duration and volume of blood loss in the one-stage posterior approach group were significantly less than those of the two-stage anteroposterior approach group [(263 ± 72) min vs (439 ± 75) min, t = -5.303, P < 0.01; (1143 ± 296) ml vs (1471 ± 399) ml, t = -2.169, P = 0.042)]. Statistical significance existed in postoperative kyphosis between two groups [(0.5 ± 2.0)° vs (3.9 ± 2.6)°, t = -3.336, P = 0.003]. Vertebral height had no statistical significance pre- and post-operatively between two groups while restoration of vertebral height did [(0.47 ± 0.19) mm vs (0.26 ± 0.15) mm, t = 2.669, P = 0.015].CONCLUSION:Posterior approach for one-stage vertebral resection, mesh implantation, pedicle screws and rod internal fixation for reconstructing spinal "three-column" structures offers excellent feasibility and safety. And it may avoid complications associated with an anteroposterior approach for two-stage procedures. The median length of hospital stay is also reduced.

BACKGROUND Theoretic advantages of cervical disc arthroplasty include preservation of normal motion and biomechanics in the cervical spine, and reduction of adjacent-segment degeneration. The clinical and radiographic effects of cervical disc arthroplasty in short term have been ascertained. The aim of this study is to research the data of mid-term results. METHODS In this prospective cohort study, 50 patients who underwent cervical disc arthroplasty from December 2003 to January 2006 were enrolled. There were 39 patients who received 1-level disc arthroplasty, and 11 patients received 2-level disc arthroplasty, with an average age of 50.9 years (range from 29 to 73). The median follow-up was 41.85 months (range from 36.00 - 55.63 months). Patients were followed prospectively with respect to their symptoms, neurologic signs, and radiographic results. RESULTS The median value of Japanese Orthopaedic Association (JOA) score was 14.0 before surgery, and 16.5 at the most recent follow-up (P < 0.01). The median value of the recovery rate of the JOA score was 92.2%. The preoperative range of motion (ROM) at the indexed level was (10.40 ± 4.97)°, which has significantly correlated with the most recent follow-up ROM which was (8.56 ± 4.76)° (P < 0.05, r = 0.33). The ROM at the operative level at the most recent follow-up was greater than the value at the 3-month follow-up of (7.52 ± 3.37)° (P < 0.05). The preoperative functional spinal unit (FSU) angulation was (-0.96 ± 6.52)°, which was not significantly correlated with that of the most recent follow-up value of (-2.65 ± 7.95)° (P < 0.01, r = 0.53). The preoperative endplate angulation was (2.61 ± 4.85)°, which had no significant correlation with that of the most recent follow-up value of (0.71 ± 6.41)° (P > 0.05). CONCLUSIONS The clinical and radiographic results of cervical disc arthroplasty are good in mid-term follow-up. The normal range of motion of the operated level and the biomechanics in the cervical spine are well preserved.

OBJECTIVE:To evaluate the effect of preoperative factors on the function of the cervical spine after Bryan artificial disc replacement.METHODS:Fifty patients who underwent cervical disc replacement from December 2003 to January 2006 were investigated. The preoperative factors such as long course of disease, lose of motion or disc height at the operation level were evaluated for their effects on the motion of the operated disc and clinical results at the time of final follow-up. There were 35 males and 15 females. Thirty-nine patients received one-level disc replacement, 11 patients received two-level disc replacement. The age of patients was from 25 to 73 years, average was 49 years.RESULTS:Until January 2009, 50 cases of all the 53 patient who got operation for more than 3 years were followed up. The follow up period was from 36.0 to 55.6 months, which showed a skewed distribution, with a median of 41.9 months. The patients, who got neural syndrome for more than 3 years, would have worse JOA recovery rate through the surgery compared with the patients who got neural syndrome less than 3 month. As for radiographic results, the preoperative range of movement (ROM) at the implanted disc spaces was 10.4 degrees +/- 5.0 degrees which had significant correlation with the most recent follow-up ROM which was 8.6 degrees +/- 4.8 degrees (r = 0.325, P < 0.05). The group which height ratio of the operative disc and the adjacent discs was less than 0.87 would have worse JOA recovery rate and range of motion at operated level at the most recent follow-up than the group more than 0.87 with statistical significance.CONCLUSIONS:For the patients with cervical spondylosis or cervical disc herniation who get nervous syndrome for more than 3 years, will have worse JOA recovery rate through the surgery, so the patient should get the operation in time to achieve better improvement. When the operated level is severe degenerated, the motion of the replaced disc and the clinical results is dissatisfied at the time of final follow-up, so it is the relative contraindications for the cervical disc replacement.

目的总结齿突畸形外科治疗的临床经验。方法 20例齿突畸形患者术前均行颈椎正侧位及屈伸侧位X线片、CT及MRI检查。采用C1/C2经关节螺钉联合椎板下钛缆固定术14例,采用C1侧块螺钉和C2椎弓根螺钉固定术3例,单纯采用椎板下钛缆固定3例。同时行枕骨大孔减压术6例。所有的螺钉均在导航引导下置入,采用自体髂骨植骨。结果全部螺钉均准确置入,无椎动脉、舌下神经及颈内动脉损伤。所有病例均达到骨性融合,脊髓症状得到缓解。结论螺钉固定联合椎板下钛缆治疗齿突畸形可以达到坚强的固定,融合率高。

目的 介绍术中即时三维导航引导下螺钉固定治疗Ⅱ型齿突骨折的临床经验,评价导航下置入齿突螺钉的安全性和准确性.方法 回顾性分析2005年11月至2009年12月采用螺钉固定治疗的20例Ⅱ型齿突骨折的患者资料,男14例,女6例;平均年龄39岁(19～64岁).16例患者为新鲜骨折,受伤至手术时间为3～21 d,平均10 d;4例为陈旧性骨折,受伤至手术时间为1～4个月(平均2.9个月).所有螺钉均在术中即时三维导航引导下置入.术后应用领托制动6个周.结果 20例患者的螺钉均准确置入,无与螺钉置入相关的并发症发生.所有患者术后获3～14个月(平均8.7个月)随防.18例患者均获骨性愈合,愈合率达90%.骨折愈合的患者无临床不适症状.结论 术中即时三维导航引导下置入齿突螺钉可以减少患者与医生的X线暴露量,有较高的安全性和准确性.

病历摘要 患者女,37岁,主诉右手麻小及行走不稳8 a.视诊可见患者发际低,但无明显短颈畸形.查体发现颈部活动范围轻度受限;四肢肌力轻度减弱,肌力约为Ⅴ级;肩肱反射阳性,双侧膝腱及跟腱反射亢进,阵李阴性;Hoffman征及Babinski征均为阳性;10 s屈伸试验:左手16次,右手14次;Tandem征刚性;JOA评分12分.

OBJECTIVE:To assess the effect of modified cervical expansive open-door laminoplasty preserving the posterior extensor musculature inserted into the C2 and C7 spinous process upon maintaining the cervical lordotic alignment and axial syndrome and to determine whether preserving the posterior extensor musculature inserted into C2 and C7 spinous process can reduce the complications.METHODS:Twenty-eight patients undergoing modified cervical expansive open-door laminoplasty preserving the posterior extensor musculature inserted into the C2 and C7 spinous process and 21 patients undergoing conventional C3-C7 cervical expansive open-door laminoplasty were investigated in pre-operative, post-operative and 3-month follow-up. The investigators assessed the effects of two different cervical laminoplasty types in the recovery rate of JOA score, the changes of Cobb angle and Ishihara's index, axial syndrome, operating duration and intra-operative blood loss, analyzed the results in SPSS and tried to find the difference in two operative types.RESULTS:There were the same results in the recovery rate of JOA score and intra-operative blood loss in modified expansive open-door cervical laminoplasty group and the conventional C3-C7 cervical expansive open-door laminoplasty group. The smaller changes of Cobb angle and Ishihara's index in the follow-up of modified laminoplasty group were found. The modified laminoplasty group had fewer patients suffering the axial syndrome in follow-up. The operating duration was shorter in the modified laminoplasty group.CONCLUSION:Preventing muscle injuries in cervical laminoplasty can reduce the incidence of complications. The modified expansive open-door cervical laminoplasty preserving the posterior extensor musculature inserted into C2 and C7 spinous process can protect cervical posterior extensor musculature. This is helpful to maintain the cervical lordotic alignment and reduce the incidence of post-operative axial syndrome.

BACKGROUND:The complicated anatomy of the cervical spine and the variation among pedicles reduces the accuracy and increases the risk of neurovascular complications associated with screw implantation in this region. In this study, we compared the accuracy of cervical (C2-C7) pedicle screw fixation assisted by X-ray fluoroscopy, computed tomography (CT)-based navigation, or intraoperative three-dimensional (3D) C-arm navigation.METHODS:This prospective cohort study was performed in 82 consecutive patients who underwent cervical pedicle screw fixation. The accuracy of screw insertion was assessed by postoperative CT scan with 3D reconstruction. The accuracy of screw insertion was assessed as: excellent (screw completely within pedicle); acceptable (≤ 1 mm screw outside pedicle cortex); poor (> 1 mm screw outside pedicle cortex).RESULTS:A total of 145 screws were inserted in 24 patients who underwent C-arm fluoroscopy. Of these, 96 screws (66.2%) were excellent, 37 (25.5%) were acceptable, and 12 (8.3%) were poor. One hundred and fifty-nine screws were inserted in 29 patients in the CT-based navigation group. Among these, 141 (88.7%) were excellent, 14 (8.8%) were acceptable, and 4 (2.5%) were poor. A total of 140 screws were inserted in 29 patients in the intraoperative 3D C-arm navigation group, of which 127 (90.7%) were excellent, and 13 (9.3%) were acceptable. No severe or permanent neurovascular complications associated with screw insertion were observed in any patient.CONCLUSIONS:CT-based and intraoperative 3D C-arm navigation were similarly accurate, and were both significantly more accurate than C-arm fluoroscopy for guiding cervical pedicle screw fixation. They were able to accurately guide the angle and depth of screw placement using visual 3D images. These two techniques are therefore preferable for high-risk cervical pedicle screw fixation. The ease and convenience of intraoperative 3D C-arm navigation suggests that it may replace virtual-fluoroscopy and CT-based navigation systems in future clinical applications.

OBJECTIVE:To evaluate the effect of axial rotation of lumbar vertebrae on the accuracy of pedicle screw placement using the traditional method, as well as to assess the value of intraoperative three-dimensional (3D) navigation in improving the accuracy.METHODS:Sixteen lumbar simulation models at different degrees of axial rotation (0°, 5°, 10° and 20°), with every four assigned with the same degree, were equally divided into two groups (traditional method group and intraoperative 3D navigation group). Random placement of pedicle screws was carried out, followed by CT scan postoperatively. Then the outer pedicle cortex contours were depicted from reconstructed sectional pedicle images using Photoshop. The accuracy of pedicle screw placement was evaluated by determining the interrelationship between screw trajectory and pedicle cortex (qualitative) and measuring the shortest distance from pedicle screw axis to outer cortex of the pedicle (quantitative).RESULTS:Eighty pedicle screws were implanted respectively in each group. In traditional method group, statistical difference existed in the accuracy of pedicle screw placement at different axial rotational degrees (P < 0.05). With degrees increasing, the accuracy declined. The accuracy of intraoperative 3D navigation group was higher than traditional method group in vertebrae with axial rotation (P < 0.01). In qualitative evaluation, the accuracy of the two methods had statistical difference when the degree was 20°, and in quantitative evaluation, statistical difference existed in 5°, 10° and 20° of vertebral axial rotation.CONCLUSIONS:Screw malposition can be caused by vertebral axial rotation in lumbar spine using traditional method. Accuracy of pedicle screw placement declines with the increase of axial rotational degrees. However, the accuracy can be improved by using intraoperative 3D navigation.

OBJECTIVE:To assess the effect of Bryan cervical disc replacement on the function of the cervical spine.METHODS:Bryan cervical artificial disc replacement was performed in 164 cases from Dec 2003 to Aug 2007, and all the cases were retrospectively followed up. Among them, 1 disc replacement was done in 132 cases, 2 discs in 28 cases and 3 discs in 4 cases with a total number of 200 artificial discs. There were 102 male patients and 62 female patients. Their age ranged from 25 to 70 years old (with an average of 47 years old). All the cases were operated according to the standard procedure for Bryan artificial disc replacement, and immobilized in a cervical collar for 2 weeks after operation. Motion of the replaced disc in sagittal direction, JOA score and satisfaction rate of the patients were followed up and evaluated.RESULTS:In this group, no acute complications happened during the operation. All patients returned to work 4 to 6 weeks after operation. The postoperative ameliorate rate of JOA score was 56%. Range of motion in sagittal direction of the operated disc was 14.4 degrees before operation, decreased to 5.7 degrees at 1 week after operation , but improved to 14.7 degrees at the time of final follow-up and was not significantly different from preoperative range. Motion in the upper adjacent disc to the replacement level was 10.9 degrees before operation, decreased to 5.5 degrees at 1 week after operation , and improved to 8.2 degrees at the time of final follow-up but was significantly smaller than preoperative range. The satisfaction rate of the patients was 94%. Loosening of the prosthesis happened in 1 case 6 months after operation but remained stable afterwards. Subsidence up to 1 mm occurred in another case 7 months after operation but also remained stable afterwards. Automatic posterior union occurred in 3 cases in which relative small size artificial discs were implanted.CONCLUSIONS:The clinical outcome of Bryan artificial disc replacement was quite good. Pre-operative range of motion of the cervical spine can be maintained.

OBJECTIVETo assess the therapeutic effects of thoracic-lumbar fracture fixation with percutaneous mini-invasive pedicle screw system guided by computer navigation.METHODFifty-one thoracic-lumbar fracture patients were divided into two groups: Sextant group (n = 21) undergoing percutaneous screw fixation with a minimally invasive pedicle screw system, and conventional pedicle screw fixation group (n = 30). The differences in the incision size, average blood loss during operation, surgical time, time of resuming walking after operation, numerical analogous pain score, etc. were analyzed.RESULTSThe incision length of the sextant group was 2.4 +/- 0.41 cm, significantly shorter than that of the conventional pedicle screw fixation group (17.4 +/- 3.4 cm, P < 0.001). The average blood loss during operation of the sextant group was 114 +/- 67.4 ml, significantly less than that of the conventional pedicle screw fixation group (317 +/- 113.2 ml, P < 0.001). The surgical time of the sextant group was 2.1 +/- 0.4 hr, significantly shorter than that of the conventional pedicle screw fixation group (2.7 +/- 0.7, P < 0.05). The time of resuming walking after operation of the sextant group was 2.0 +/- 0.7 d, significantly shorter than that of the conventional pedicle screw fixation group (7.2 +/- 2.5 d, P < 0.001). The postoperative NAPS was significantly lower than that before operation in both groups, however, there was no significant difference in the improvement of NAPS between the two groups.CONCLUSIONPercutaneous pedicle screw fixation using mini-invasive pedicle screw system guided by computer navigation is a good surgical therapeutic choice in thoracic-lumbar fracture.

OBJECTIVE:To evaluate the clinical outcomes of multi-level cervical Bryan disc replacement.METHOD:Twenty patients with diseases of cervical vertebrae underwent multi-level cervical Bryan disc replacements, 18 patients undergoing double-level displacement and 2 undergoing triple-level displacement. Roentgenography was used to examine the movement of replacement segment, height of movement segment, and movement of the adjacent-segments. Japanese Orthopaedic Association (JOA) score, neck disability index (NDI) score, and Odom's standards were evaluated.RESULT:The average movement of the replaced segment could be preserved to 86.2% that of the original degree, the overall movement of cervical could be preserved to 87.3% that of the original degree l. The post-operative JOA score was 16.1 1.6, p significantly higher than that before operation (12.7 +/- 3.0, P < 0.05) with an improvement rate was very good in 80.1%. The follow-up NDI score was 8.6 +/- 7.5. According to the Odom's standards, the outcome was very good in 50% of the patient, good in 40%, and OK in 10%. The radiographic measurements showed no significant difference in the cervical curve between the pre-operative and post-operative values.CONCLUSION:An encouraging option for anterior cervical fusion, multi-level cervical Bryan disc replacement can not only preserve the cervical physiological movement and curve, but also decrease the degeneration of adjacent-segment.