Cervical range of motion and alignment after laminoplasty preserving or reattaching the semispinalis cervicis inserted into axis

STUDY DESIGN: A radiographic study in 111 patients using radiographs was conducted. OBJECTIVE: To clarify whether the modified laminoplasty with C3 laminectomy preserving the semispinalis cervicis (SSC) inserted into C2 could maintain the postopertive range of motion (ROM) and sagittal alignment compared with conventional C3-C7 laminoplasty reattaching the muscle to C2. SUMMARY OF BACKGROUND DATA: Intraoperative injury of the SSC is relevant to the significant loss of ROM and the malalignment after laminoplasty. To expose the C3 lamina, however, the SSC inserted into C2 could not be preserved in conventional C3-C7 laminoplasty. METHODS: The ROM and sagittal alignment of 70 patients (group A) (52 men, 18 women, mean age 59 y, mean follow-up period 1 y and 7 mo) with C4-C7 laminoplasty with C3 laminectomy were compared with those of 41 patients (group B) (28 men, 13 women, mean age 59 y, mean follow-up period 2 y and 6 mo) with C3-C7 laminoplasty using radiographs of the cervical spine. RESULTS: Regarding C2-C7 ROM, the postoperative ROM was larger (P=0.003) and the decrease rate of ROM was smaller (P=0.0006), and decreased ROM in extension was smaller (P<0.0001) in group A. Regarding O-C2 ROM, the increased ROM was smaller (P=0.043) and increased ROM in extension was smaller (P=0.001) in group A. Regarding O-C7 ROM, the postoperative ROM was larger (P=0.029) in group A. Regarding the cervical alignment, the increased lordotic angle at O-C2 was smaller (P=0.046) in group A. CONCLUSIONS: This modified laminoplasty preserving the SSC inserted into C2 is an effective procedure for maintaining postoperative ROM, especially in extension, and sagittal alignment of the upper cervical spine well.     

单节段ProDisc-C颈椎人工椎间盘置换术对颈椎曲度和活动度的影响

目的:观察单节段ProDisc-C颈椎人工椎间盘置换术后置换节段活动度和颈椎曲度变化情况,分析ProDisc-C人工椎间盘置换术的效果.方法:2006年6月～2008年9月对53例颈椎病患者行单节段前路减压、ProDisc-C人工椎间盘置换术,置换节段C3/4 7例,C4/5 10例,C5/6 27例,C6/7 9例.应用医学影像存储与传输系统(PACS)测量术前和末次随访时置换节段活动度(ROM)、置换节段脊柱功能单位(functional spinal unit,FSU)Cobb角和颈椎整体曲度(C2～C7 Cobb角).结果:随访3～36个月,平均13.8个月.术前置换节段ROM为8.60°±3.7°,末次随访时为9.7°±3.5°,有统计学差异(P<.05);术前PSU Cobb角(前凸为正值)为0.1°±4.8°,末次随访时为3.6°±4.5°,有统计学差异(P<.05);术前颈椎整体曲度为7.0°±10.2°,末次随访时为8.0°±10.4°,无统计学差异(P>.05).结论:单节段ProDisc-C颈椎人工椎间盘置换术后置换节段活动度较术前增大,颈椎整体曲度无明显变化,FSU前凸增大,对于术前病变节段FSU生理前凸变小或轻度后凸的拟行颈椎人工椎间盘置换的患者可选择ProDisc-C假体.     

Cervical alignment and range of motion after laminoplasty: radiographical data from more than 500 cases with cervical spondylotic myelopathy and a review of the literature

STUDY DESIGN.: A large-scale analysis of radiographical results of patients with cervical spondylotic myelopathy and a review of the literature. OBJECTIVE.: To identify changes in sagittal alignment and range of motion (ROM) after cervical laminoplasty. SUMMARY OF BACKGROUND DATA.: Cervical laminoplasty is an effective procedure for decompressing multilevel spinal cord compression. It often induces postoperative complications such as loss of lordotic alignment and restriction of neck motion. Although numerous studies have reported the loss of flexion-extension ROM after laminoplasty, no large-scale study has been reported. METHODS.: Five hundred twenty consecutive patients with cervical spondylotic myelopathy (331 male and 189 female; mean age, 62.2 yr) who underwent modified double-door laminoplasty were enrolled. The average follow-up period was 33.3 months. All patients were allowed to sit up and walk on the first postoperative day using an orthosis, which could be removed within the first 2 weeks, even if long. Early cervical ROM exercises were performed as a part of the rehabilitation schedule. Radiography was performed before surgery and at the final follow-up. Cervical alignment in the neutral and flexion-extension view were measured by the Cobb method at C2-C7. The ROM was assessed by measuring the difference in alignment between flexion and extension. RESULTS.: The mean C2-C7 alignment in the neutral position was 11.9° lordotic preoperatively and 13.6° lordotic postoperatively; the alignment increased by 1.8° in lordosis. The mean total ROM decreased from a preoperative value of 40.1° to 33.5° at the final follow-up, showing a significant difference of 6.6°. The mean total ROM preservation after laminoplasty was 87.9%. CONCLUSION.: Sagittal alignment was slightly changed, with only a 1.8° increase in lordosis. The ROM of the cervical spine was preserved by 87.9%. This preservation of alignment and ROM might be attributable to improvements including early removal of the cervical orthosis, postoperative neck exercises, and some surgical modifications.     

Postoperative instability after laminoplasty for cervical myelopathy with spondylolisthesis

OBJECTIVE: 76 patients who underwent laminoplasty for cervical spondylotic myelopathy were investigated regarding the impact of preoperative and postoperative degenerative spondylolisthesis on their neurologic outcome. METHODS: Radiographs were obtained 1 year postoperatively to investigate range of motion (ROM), lordotic curvature, and postoperative spondylolisthesis. RESULTS: By 1 year after surgery, 85% of those spondylolistheses present preoperatively had either resolved or improved on neutral lateral radiographs. The cross-sectional area of the spinal cord at the site of spondylolisthesis was measured using preoperative computed tomography myelography. Clinical results were evaluated by the recovery rate using Japanese Orthopaedic Association score. Patients with posterior spondylolisthesis showed a significantly poorer postoperative recovery rate. Intervertebral ROM in patients with preoperative spondylolisthesis was reduced, whereas cervical alignment had not deteriorated after laminoplasty. The group with posterior spondylolisthesis showed a significant reduction in the cross-sectional area of the spinal cord at the site of spondylolisthesis. Postoperative spondylolisthesis appeared in 15 patients, 10 of whom had preoperative spondylolisthesis at an adjacent site. CONCLUSION: The cause of poorer surgical results of those patients with preoperative posterior spondylolisthesis appears to be related to a higher degree of spinal cord compression than with preoperative anterior spondylolisthesis.     

Cervical laminoplasty for cervical myeloradiculopathy

The role for treatment of conditions resulting in cervical spondylotic myeloradiculopathy through posterior approaches is discussed. The indications and advantages of a posterior approach andin particular laminoplasty are reviewed. Various techniques of laminoplasty are presented. The senior author's technique and series in expansive open door laminoplasty is also reviewed. The series was a prospective study performed to evaluate the clinical result, and the position of the open door laminae in the postoperative period. Cervical open door expansive laminoplasty was performed on 22 patients for cervical spondylotic myeloradiculopathy. Preoperative Nurick's classification and the Japanese Orthopaedic Association score averaged 1.9 and 11.9, respectively. At follow-up (mean, 25.9 months; range, 15 to 40 months), NUR³ classification and JOA scores improved to 0.8 and 15.3, respectively. Digital analysis of serial computed tomography scans shows an average increase in the anteroposterior sagittal diameter of 58% (7.1 mm) with an associated settling of 10% (1.7 mm). Early postsurgical complications include one complete loss of an open door laminar position, and two cases of transient radiculopathy. The transient cases of radiculopathy were related to a fracture of the laminar hinge causing root impingement in one case, and the other caused by nerve root traction at the nonhinged side. Recommendations include a generous open door for the laminoplasty in anticipation of postoperative settling, and foraminal decompression for foraminal radiculopathy. Laminoplasty provides excellent clinical results in patients with myeloradiculopathy caused by cervical spondylotic stenosis and ossification of the posterior longitudinal ligament.     

Flexibility and alignment of the cervical spine after laminoplasty for spondylotic myelopathy

Summary The long term effects of laminoplasty on cervical movement and alignment were investigated by radiography and CT scans in a study of 56 patients with multisegmental myelopathy who had undergone a C3 to C7 open-door laminoplasty. Follow up averaged 5.8 years. Satisfactory neurological improvement occurred in 73%. Cervical flexion decreased by 35% and extension by 57%; the decrease of both movement was statistically significant. Decreased vertebral slip, as well as slightly reduced lordosis, was seen after operation. Increase in measured canal size after operation and at follow up was 48% and 40%; 8% of the expanded canal size was lost at the last follow up. Expansive open-door laminoplasty leads to a better neurological prognosis in this group of patients, while maintaining an increase in canal size and preserving spinal stability.

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Résumé Les effets à long terme de la laminoplastie sur la mobilité et l'alignement du rachis cervical ont été étudiés par radiographie et tomodensitométrie. Le travail a porté sur 56 patients atteints de myélopathie spondylitique multisegmentaire, ayant subi une laminoplastie ouverte C3–C7 avec une greffe osseuse réalisant un espaceur autogène. Le recul est en moyenne de 5.8 ans (de 2 à 10.4) et les résultats ont montré une amélioration neurologique satisfaisante dans 73% des cas. La flexion était diminuée de 35% et l'extension de 57%. Cette diminution de la mobilité était statistiquement significative. On a également observé une réduction du glissement vertébral et une légère réduction de la lordose. L'augmentation de la taille du canal après l'intervention chirurgicale était de 48% et de 40% au dernier examen; à ce moment elle avait disparu dans 8% des cas. Les laminoplasties ouvertes étendues assurent un meilleur pronostic neurologique chez les patients atteints de spondylite multisegmentaire en maintenant la taille du canal et en préservant la stabilité vertébrale.

     

Assessing range of cervical rotation after laminoplasty using axial CT

PURPOSE: Although many authors have reported on cervical range of motion after laminoplasty, they have focused on flexion and extension based on lateral radiographs, not on axial rotation. In this study, we assessed cervical rotation from C1 to T1 after laminoplasty using computed tomography. PATIENTS AND METHODS: Eighteen consecutive patients with cervical myelopathy who had undergone laminoplasty were observed. Patient was placed in the supine position on the computed tomography scan table. After the scans in this neutral position were completed, the patient actively rotated his neck as far as possible taking care that the shoulders remained in the horizontal plane. We measured the C1 to T1, C1 to C2, and C2 to T1 rotation angles preoperatively, and at 2 weeks and 6 months after surgery. RESULTS: The average C1 to T1 rotation angles preoperatively were 46 degrees on the right and 45 degrees on the left. The percentage of C1 to C2 rotation during global cervical rotation (C1 to T1) was 62%. C1 to T1 rotation angle significantly decreased at two weeks after surgery but recovered to almost preoperative levels (11% decreases) by 6 months after surgery with no difference between right and left motion. The average C2 to T1 subaxial rotation angles did not significantly decreased after surgery. CONCLUSIONS: Rotation angle after laminoplasty decreased slightly at 2 weeks after surgery but recovered almost to preoperative levels by 6 months. Subaxial rotation (C2 to T1) angles did not significantly decreased after surgery.     

Cervical laminoplasty vs cervical laminectomy with fusion

Cervical spinal stenosis is a commonly encountered condition. Symptoms of radiculopathy are ameliorable to conservative measures. However, central canal stenosis in the setting of myelopathy is a disease warranting surgical intervention. To decompress the spinal cord, the canal needs to be expanded. Traditionally this can be accomplished via a laminectomy. The occurrence of postoperative deformity has led to the advent of other surgical techniques to address spinal stenosis. Both cervical laminoplasty and laminectomy with posterior fusion are available options that may prevent the progression of cervical instability or deformity or both. This article discusses the treatments available and outlines the benefits of each.     

Cervical muscle strength after laminoplasty

 To determine changes in cervical muscle strength after laminoplasty and to evaluate the relation between muscle strength and neck pain, we measured maximum isometric muscle strength using a handheld dynamometer. We also investigated neck pain before surgery and every month after surgery in 21 subjects who had undergone French-door laminoplasty. Muscle strength decreased particularly 1 month after surgery, the extensor muscles being affected more than the flexors. The strength of both muscle groups increased gradually; and at 1 year after surgery they had regained their presurgical status. All of the subjects complained of severe neck pain after 1 month. Their complaints began to decrease a few months after surgery, although they were still present in nine patients at 1 year after surgery. The correlation between muscle strength and neck pain was strongly negative for extension and flexion in men and for extension in women. No correlation was found between flexor muscle strength and neck pain in women. The extension/flexion ratio was significantly high in the neck pain group 1 year after surgery. Our results suggest that symptoms within a few months after surgery are due to surgical trauma to the soft tissues but that chronic neck pain derives from an imbalance of the two muscle strengths. Received: May 15, 2002 / Accepted: August 7, 2002 Offprint requests to: S. Nakama     

Sagittal range of motion after extensive cervical fusion

Background contextComplicated cervical spine revision and deformity correction surgeries are becoming increasingly common. These challenging operations often necessitate fusion of the entire cervical spine. Patients frequently express concern over the likely loss of range of motion (ROM) of the neck postoperatively. However, we are aware of no study that specifically examines the sagittal cervical ROM after extensive cervical fusion.PurposeTo characterize sagittal ROM after extensive cervical fusion.Study designRetrospective case series.Patient sampleThirty patients were included.Outcome measuresRadiographs at final follow-up were measured for cervical ROM by the occipitocervical and cervicosternal angles with the neck in full flexion and extension.MethodsThe surgical and medical records at one tertiary referral academic institution were used to identify adults who had undergone extensive cervical fusion between 1996 and 2008. An “extensive cervical fusion” entailed an upper instrumented vertebra proximal to C3 and lower instrumented vertebra distal to C7. Radiographs at final follow-up were measured for cervical ROM by the occipitocervical and cervicosternal angles with the neck in full flexion and extension.ResultsThe average age at surgery was 58.3±10.0 years. The surgical levels were occiput–T1 (one patient), occiput–T4 (one patient), occiput–T6 (one patient), C1–T1 (one patient), C1–T2 (one patient), C2–T1 (nine patients), C2–T2 (eight patients), C2–T3 (six patients), and C2–T4 (two patients). Twenty-seven of the procedures were revisions. The other surgical indications were chin-on-chest deformity (one patient), cervical scoliosis (one patient), and multilevel cervical myelopathy (one patient). The mean follow-up period was 34.5±30.9 months (range, 6–154 months). The mean cervical ROM values by the occipitocervical and cervicosternal angles were 29.5±11.0° and 7.5±5.0°, respectively. The mean total cervical ROM value was 34.1±14.7°.ConclusionsA substantial degree of sagittal ROM can be maintained after extensive surgical fusion of the cervical spine.     

Analysis of the cervical spine alignment following laminoplasty and laminectomy

Very little detailed biomechanical examination of the alignment of the cervical spine following laminoplasty has been reported. We performed a comparative study regarding the buckling-type alignment that follows laminoplasty and laminectomy to know the mechanical changes in the alignment of the cervical spine. Lateral images of plain roentgenograms of the cervical spine were put into a computer and examined using a program we developed for analysis of the buckling-type alignment. Sixty-four patients who underwent laminoplasty and 37 patients who underwent laminectomy were reviewed retrospectively. The subjects comprised patients with cervical spondylotic myelopathy (CSM) and those with ossification of the posterior longitudinal ligament (OPLL). The postoperative observation period was 6 years and 7 months on average after laminectomy, and 5 years and 6 months on average following laminoplasty. Development of the buckling-type alignment was found in 33% of patients following laminectomy and only 6% after laminoplasty. Development of buckling-type alignment following laminoplasty appeared markedly less than following laminectomy in both CSM and OPLL patients. These results favor laminoplasty over laminectomy from the aspect of mechanics.     

颈椎曲度和活动度参数的影响因素

 目的 探讨颈椎曲度和活动度的测量参数及影响因素。方法 回顾性分析2012年1月至2013年6月,212位正常志愿者的颈椎标准侧位、前屈位、后伸位X线片,男84位,女128位;年龄20~79岁,以10年为一组,分成6组;颈椎间盘退变程度依据颈椎9分法,分为4组。影像资料由3名脊柱外科医生分3次运用Mimics软件测量。测量参数包括C2~C7曲度及椎间各节段和整体活动度。对颈椎曲度和整体活动度的关系进行Pearson 相关性分析,对年龄、性别和间盘退变三个因素进行多重线性回归分析。组内相关系数（ICC）评估测量者组内和组间一致性。结果 C₂~C₇曲度为21.40°±12.15°,C₂~C₇整体活动度为 63.59°±15.37°。性别对颈椎曲度的影响有统计学意义（回归系数=-2.472,P＜ 0.05）。性别和年龄两因素对颈椎整体活动度的影响有统计学意义（回归系数=3.863和-6.463,P＜0.05）。性别对C_2,3、C_5,6两个节段活动度的影响有统计学意义;年龄对C₂~C₇所有五个节段活动度的影响有统计学意义;间盘退变对C_4,5、C_5,6和C_6,7三个节段活动度的影响有统计学意义。颈椎曲度与颈椎整体及后伸活动度无明显相关性（r=-0.106和0.215,P＞0.05）,但与前屈活动度呈负相关（r=-0.401,P＜0.05）。颈椎曲度、整体活动度和节段活动度的测量结果均具有很高的组内一致性（ICC=0.97,0.96~0.97;ICC=0.91,0.90~0.92;ICC=0.89,0.87~0.91）和组间一致性（ICC=0.94,0.92~0.95;ICC=0.89,0.86~0.91;ICC=0.83,0.79~0.86）。结论 性别是颈椎曲度的影响因素,性别和年龄两因素是颈椎整体活动度的影响因素,性别、年龄和间盘退变程度是颈椎节段活动度的影响因素。     

Kinematics after cervical laminoplasty: risk factors for cervical kyphotic deformity after laminoplasty

BACKGROUND CONTEXTLaminoplasty of the cervical spine is widely used as an effective surgical method to treat compressive myelopathy of the cervical spine; however, there is an adverse effect of kyphosis after surgery. The risk factors or predictors of kyphosis have not been sufficiently evaluated.PURPOSETo assess the risk factors for kyphosis following laminoplasty.STUDY DESIGNRetrospective study.PATIENT SAMPLEPatients diagnosed with cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL) who underwent laminoplasty between May 2011 and October 2018 were enrolled.OUTCOME MEASURESChanges in lordosis and range of motion (ROM).METHODSRadiological imaging data were collected from simple neutral and flexion-extension radiographs at baseline and at 2-year follow-up. The ROM from the neutral position to complete flexion was defined as the flexion capacity, and the ROM from the neutral position to complete extension was defined as the extension capacity.RESULTSThis study included 53 patients (mean age, 59.3 years). Multivariate linear regression analysis revealed that, the smaller the preoperative extension capacity, the greater was the decrease in lordosis (p=.025), while the larger the T1 slope, the greater was the decrease in lordosis following laminoplasty (p= .008). Correlation analysis revealed that C2-7 lordosis increased with increasing baseline T1 slope before surgery (p< .01). In patients with large preoperative C2-7 lordosis, the postoperative decrease in ROM tended to be greater (p= .028). However, the degree of lordosis and ROM reduction did not demonstrate a clear correlation with the clinical outcomes at 2 years after surgery.CONCLUSIONSKyphotic changes in the cervical spine following laminoplasty were related to preoperative radiological parameters. The greater the preoperative extension capacity, the lower was the decrease in lordosis, and the greater the T1 slope, the greater was the decrease in lordosis.     

单开门椎管扩大椎板成形术联合侧块螺钉治疗脊髓型颈椎病伴颈椎不稳

目的:探讨单开门椎管扩大椎板成形术联合侧块螺钉治疗脊髓型颈椎病伴颈椎不稳的疗效。方法:2010年3月至2012年10月,采用单开门椎管扩大椎板成形术联合侧块螺钉治疗脊髓型颈椎病伴颈椎不稳患者25例,其中男18例,女7例;年龄57~68岁,平均57岁。记录术前及末次随访时的JOA评分,对患者临床症状改善进行分析。同时记录Cobb角及颈椎活动度,分析颈椎退变程度。结果:33例患者均获随访,时间18~36个月,平均25.6个月。出现脑脊液漏1例,切口脂肪液化1例,C5神经根麻痹4例,JOA评分由术前的5.2±2.1增加至末次随访时的11.3±2.4(P0.05),Cobb角由术前的(6.5±3.4)°提升至末次随访时的(13.2±4.9)°(P0.05)。颈椎活动度由术前的(30.4±9.2)°下降至末次随访时的(26.5±8.7)°(P0.05)。结论:单开门椎管扩大椎板成形术联合侧块螺钉治疗脊髓型颈椎病伴颈椎不稳疗效良好,具有适用范围广、牢固等优点,但要减少并发症的发生。     

Segmental cervical instability does not drive the loss of cervical lordosis after laminoplasty in patients with cervical spondylotic myelopathy

BACKGROUND/CONTEXTKyphotic deformity after cervical laminoplasty (CLP) often leads to unfavorable neurological recovery due to insufficient indirect decompression of the spinal cord. Existing literature has described that segmental cervical instability is a contraindication for CLP because it is a potential risk factor for kyphotic changes after surgery; however, this has never been confirmed in any clinical studies.PURPOSETo confirm whether segmental cervical instability was an independent risk factor for postoperative kyphotic change and to examine whether segmental cervical instability led to poor neurological outcomes after CLP for cervical spondylotic myelopathy (CSM).STUDY DESIGN/SETTINGA retrospective studyPATIENT SAMPLEPatients who underwent CLP for CSM between January 2013 and January 2021 with a follow-up period of ≥1 year were enrolled.OUTCOME MEASURESCervical radiographic measurements including C2–C7 lordosis (C2–7 angle), cervical sagittal vertical axis, C7 slope, flexion range of motion (fROM) and extension ROM (eROM) were assessed using neutral and flexion-extension views. Segmental cervical instability was classified into anterolisthesis (AL) of ≥2 mm displacement, retrolisthesis (RL) of ≥2 mm displacement, and translational instability (TI) of ≥3 mm translational motion. The amount of C2–7 angle loss at the follow-up period compared to the preoperative measurements was defined as cervical lordosis loss (CLL). Neurological outcomes were assessed using the recovery rate of the Japanese Orthopedic Association score (JOA-RR).METHODSCLL was compared among patients with and without segmental cervical instability. Further, multiple linear regression model for CLL was built for the evaluation with adjustment of the reported risks, including cervical sagittal vertical axis, C7 slope, fROM, eROM, and patient age together with AL, RL, and TI, as independent variables. The JOA-RR was also compared between patients with and without segmental cervical instability.RESULTSA total of 138 patients (mean age, 68.7 years; 65.9% male) were included in the analysis. AL, RL, and TI were found in 12 (8.7%), 33 (23.9%), and 16 (11.6%) patients, respectively. Comparisons among the groups showed that AL led to greater CLL; however, RL and TI did not. Multiple linear regression analysis revealed that greater CLL is significantly associated with greater fROM and smaller eROM (regression coefficient [β]=0.328, 95% confidence interval: 0.178 to 0.478, p<.001; β=?0.372, 95% confidence interval: ?0.591 to ?0.153, p=.001, respectively). However, there were no significant statistical associations in the AL, RL, and TI. Whereas, patients with AL tended to exhibit lower JOA-RR than those without AL (37.8% vs. 52.0%, p=.108).CONCLUSIONSSegmental cervical instability is not the definitive driver for loss of cervical lordosis after CLP in patients with CSM; thus, is not a contraindication in and of itself. However, it is necessary to consider the indications for CLP, according to individual cases of patients with AL on baseline radiograph, which is a sign of poor neurological recovery.     

Curvature and range of motion of the cervical spine after laminaplasty

BACKGROUND: The curvature and range of motion of the cervical spine decrease after laminaplasty. However, to our knowledge these changes have not been studied prospectively. Also, the effect of laminaplasty on the mobility of the occipito-atlanto-axial joints has not been studied in detail. The purpose of our study was to prospectively evaluate the range of motion and curvature of the cervical spine, including the occipito-atlanto-axial joints, following laminaplasty. METHODS: We conducted a prospective study of twenty-six patients who underwent cervical laminaplasty. They were followed for a mean of 6.7 years (range, five to nine years). Radiographs were made before the operation and at one, three, and five years after the operation. The curvature index, the angle of each vertebra in the neutral position from the occiput to the seventh cervical vertebra, and the range of motion in the sagittal plane were measured. RESULTS: The curvature index, the angle of the axis and the sixth cervical vertebra, and the angle of the axis and the seventh cervical vertebra in the neutral position were reduced after the operation. The rate of reduction declined between the third and fifth postoperative years. On the other hand, the mean distance between the occiput and the atlas as well as the mean angle of the axis and the atlas did not change significantly. The range of motion of the axis and the seventh cervical vertebra was decreased after the operation, and it continued to decrease slowly over the study period. The range of motion of the occipito-atlanto-axial complex increased slightly, which may represent a compensation for the decreased mobility of the middle and caudad parts of the cervical spine. CONCLUSIONS: Laminaplasty diminishes lordosis and straightens the cervical spine. The range of motion and lordosis continued to decrease, though at a diminishing rate, between the third and fifth postoperative years.     

保留颈后方韧带复合体单开门椎管扩大成形术后其颈椎生理曲度及活动范围的中远期随访

【摘要】 目的：观察保留颈后方韧带复合体重建伸肌附着点单开门椎管扩大成形术治疗脊髓型颈椎病对颈椎生理曲度、活动范围的中远期影响。方法：2005年1月～2008年1月采用保留颈后方韧带复合体联合重建伸肌附着点单开门椎管扩大成形术治疗脊髓型颈椎病20例患者,其中男性12例,女性8例,年龄37～68岁,平均52岁。比较患者手术前后JOA评分、颈椎生理曲度（C2～C7 Cobb角）及活动范围（ROM）。结果：20例患者均获随访,随访5～8年,平均7年。JOA评分术前为7～13分,平均9.5分;末次随访时为9~17分,平均14.0分,与术前比较明显改善（P＜0.05）,改善率为52%。C5椎管/椎体比率术前为0.56～0.8,平均0.67;末次随访时为0.86～1.42,平均1.21,与术前比较椎管矢状径扩大明显（P＜0.05）。术前C2～C7 Cobb角中立位为0°～16°,平均7.8°;末次随访时为4°～16°,平均8.6°,与术前比较差异有显著性（P＜0.05）,过伸位31°（24°～38°）,过屈位-2.7°（-11°～0°）。术后颈椎前凸无明显减少,所有随访患者无一例出现后凸畸形。但术后颈椎活动范围较术前减少,平均ROM为28°,与术前（42.1°）比较差异有显著性（P＜0.05）,过伸位26°（21°～29°）,与术前（28°）比较差异无显著性（P＞0.05）,过屈位7°（5.5°～19°）,与术前（16°）比较差异有显著性（P＜0.05）。回植的棘突与掀起的椎板骨性融合,回植的C2棘突附着点及椎板的门轴侧均骨性愈合,未出现再次关门情况,椎管形态维持良好。结论：保留颈后方韧带复合体重建伸肌附着点单开门椎管扩大成形术治疗脊髓型颈椎病对维持生理曲度具有良好效果,但颈椎活动范围有部分丢失。     

Cervical instability in cervical spondylosis patients

Background

Cervical spondylosis is one of the most common causes of cervical instability. Various methods are used for measuring cervical instability on X?ray films. The purpose of this study was to assess the application of the radiographic index method to analyze the radiographic features of cervical spondylosis instability.

Material and methods

Digitized dynamic radiographs of 121 subjects with cervical spondylosis were retrospectively retrieved. The cervical spondylosis patients were divided into two groups according to the symptoms: patients with positive neurological deficits with and without neck symptoms (group I, n?=?62) and patients with neck symptoms only (group II, n?=?59). A total of 62 healthy subjects were assigned to the control group (group III). The radiographic indices of cervical curvature, the full flexion to full extension ranges of motion (ROM) and horizontal displacement of the three groups were analyzed and compared with each other.

Results

On flexion-extension views there were significant differences (p?=?0.00000 [significance of cervical lordosis on flexion view between the three groups], p?=?0.00271 [significant difference of cervical lordosis between the three groups on extension view]) between the three groups concerning the cervical lordosis: group I had the least cervical curvature, followed by group II and group III. The full flexion to full extension ranges of motion for group I was significantly decreased (p?=?0.0039) when compared with group II and group III. The horizontal displacement at each segmental level (except C2/C3) was significantly higher in group I than that of the other two groups.

Conclusion

With the application of the radiographic index method, cervical spine lordosis, the full flexion to full extension ROM, horizontal displacement, and cervical instability can be accurately illustrated. Cervical spondylosis is an age-related, wear and tear change of the spine that occurs over time. The index of the horizontal displacement ≥0.3 is suggestive of cervical instability.

     

颈椎后纵韧带骨化症单开门椎管扩大成形术后颈椎矢状位参数变化与疗效的关系

目的 :探讨颈椎后纵韧带骨化症(OPLL)患者行颈后路单开门椎管扩大成形术后颈椎矢状位参数变化与手术疗效的关系。方法:选取2009年1月~2013年1月在我院接受颈后路单开门椎管扩大成形术的OPLL患者68例,随访12~30个月。记录手术前后JOA(Japanese Orthopaedic Association)评分、颈肩臂疼痛VAS(visual analog scale)评分,计算神经功能JOA改善率(improvement rate,IR)。术前、术后和随访时行颈椎正侧位X线片、CT三维重建和MRI检查,测量术前及随访时的颈椎矢状位参数,包括C2-C7 Cobb角、C2-C7矢状面轴向距离(sagittal vertical axis,SVA)和T1倾斜角。结果:末次随访时JOA评分及VAS评分较术前明显改善(P0.001),神经功能恢复为优者21例,良30例,中14例,差3例,优良率为75%。末次随访时C2-C7 Cobb角由术前的15.4°±9.5°增大到17.4°±10.2°,但差异无统计学意义(P=0.166);C2-C7 SVA由术前的21.0±15.3mm增大到27.0±15.7mm,差异有统计学意义(P=0.009);T1倾斜角由术前的30.2°±10.1°增大到33.7°±8.0°,差异有统计学意义(P=0.044)。术前T1倾斜角与C2-C7 Cobb角正相关(r=0.569,P0.01),与C2-C7 SVA正相关(r=0.544,P0.01)。C2-C7 Cobb角与C2-C7 SVA无显著相关性(r=0.05,P=0.798)。末次随访时C2-C7 Cobb角较术前增大24例,较术前减小44例,两组JOA评分和VAS评分变化、神经功能改善率无统计学差异;C2-C7SVA增加46例,减小22例,两组JOA评分和VAS评分变化、神经功能改善率亦无统计学差异(P0.05)。结论 :颈后路单开门椎管扩大成形术治疗OPLL短期疗效确切,手术前后颈椎矢状参数的变化与患者的临床疗效无显著相关性。