Objective To analyze the biomechanical changes of the adjacent cervical facet joints when the angled cervical prosthesis is replaced. Methods A total of 400 northwestern people were involved, with an age of 40 years or older.The cervical vertebra lateral X-ray films were taken, and the cervical angles were measured by professional computer aided design software, then the cervical intervertebral disc prosthesis with 10° angle was designed. The finite element models of C4，5and C4-6 segments with intact cervical discs were developed; the C4，5 disc was replaced by the cervical prosthesis with 0° and 10° angle respectively; and then all models were subjected to axial loading, flexion/extension, lateral bending, and torsion loading conditions; the stress effects on adjacent facet joints after replacement were observed by comparing with that of the intact model. Results The cervical angles were (9.97 ± 3.64)° in C3，4, (9.95 ± 4.34)° in C4，5, (8.59 ± 3.75)° in C5，6, and (8.49 ± 3.39)° in C6，7, showing no significant difference between C3，4 and C4，5, C5，6 and C6，7 (P gt; 0.05) and showing significant differences between the other cervical angles (P lt; 0.05). When C4，5 model was axially loaded, no significant difference in equivalent shearing stress were observed in intact, 0°, and 10° groups; at flexion/extension loading, the stress was biggest in intact group, and was smallest in 10° group; at lateral bending, the stress got the high rank in intact group, and was minimum in 10° group; at torsion loading, the stress state of 10° group approached to the intact one condition. When C4-6 model was loaded, the facet joint stress of the replaced segment (C4，5) decreased significantly at axial loading, flexion/extension, and lateral bending; while no obvious decrease was observed at torsion loading; the stress of the adjacent inferior disc (C5，6) decreased significantly at axial loadingand lateral bending condition, while less decrease was observed at torsion loading, no significant change at flexion/extension condition, it approached to that of the intact one. Conclusion The finite element analysis reveals that the biomechanical properties of 10° designed prosthesis is approximate to that of the intact cervical disc, thus the 10° designed prosthesis can meet the requirements of biomechanical function reconstruction of the cervical spine.
Objective To explore the factors to affect severity of hyperextension injury of the cervical spinal cord (HEICSC). Methods Forty-five patients with HEICSC, 35 males and 10 females, aged 27-67 years old (mean 48.2 years old), were retrospectively analyzed. The disease course was 30 minutes to 16 days. According to modified Frankel grading, there were 6 cases of grade A, 8 cases of grade B, 16 cases of grade C and 15 cases of grade D. Spinal cord injuries (SCI) segments were determined according to SCI plane and high signal change (HSC) in spinal cord on MR images. The whole or large part of HSC segments were supposed to be main injured spinal cord segments (MISCSs) and the staccato or patchy HSC ones were supposed to be common injured spinal cord segments (CISCSs). When the external force acting on head or face suffered was larger, the force produced during high-speed movement or forehead and/or face had severe contused and/or) lacerated wound, the force was defined severe traumatic strength, whereas the reverse was true for sl ight traumatic strength. According to signal magnitude of the cervical discs on T2-weighted MR images, degeneration of cervical discs and cervical vertebras were classified into 5 grades: grade 0-4. Cervical spinal stenosis were graded to 5 grades according to the width of anterior or posterior cerebrospinal fluid layer to spinal cord on T2-weighted MR images and compressed degree of spinal cord on T1-weighted MR images. The influence of traumatic strength, cervical spinal degeneration or cervical spinal stenosis on SCI were explored. Results Among the 45 cases, 12 cases were caused by sl ight traumatic strength, 33 cases were caused by severe one. The cervical spinal cord was injuried more sl ightly and the patients were older in the sl ight traumatic strength cases than in the severe ones (P lt; 0.05). The number of MISCSs were 45 in 40 cases and the 25 segments were located at C3, 4 level. The number of CISCSs were 39 in 21 cases. All the cervical vertebraes of the 45 patients had degenerated. The most were in grade 3 in 22 patients and the severest degenerative segments were mostly located in C5,6 discs in 35 ones. The number of the MISCSs in different degenerative grades of discs was 0 in grade 0, 9 in grade 1, 20 in grade 2, 14 in grade 3, and 2 in grade 4. The ratios of the segment number of injuried spinal cord to the segment number of spinal stenosis in every grade of stenosis were 1/62 in grade 0, 2/11 in grade 1, 27/52 in grade 2, 33/33 in grade 3, 21/22 in grade 4. Conclusion Three main factors including the magnitude of traumatic strength, the degree of instabil ity of cervical vertebrae and the degree of cervical stenosis contribute to development and progress of HEICSC.
To probe the etiopathogenisis of adjacent-segment disease by analyzing the imageology data and cl inical neurological function in patients with anterior cervical discectomy and fusion (ACDF) harvested by long-term follow-up. Methods A retrospective study was performed on 52 patients who had undergone ACDF with perfect documents from January 1990 to April 2003. Of the patients, 45 were males and 7 were females with a mean age of 48.5 years (range from 25 to 72 years). There was the fusion of 10 one-levels, 38 two-levels and 4 three-levels. The cervical anterior-posterior and lateral X-ray, CT and MRI examination were performed before the operation. Cl inical neurological function was recorded by the Nurick score, and this score at 6 weeks after the operation was compared with the later follow-up. In the radiological examination, the motion of adjacent vertebrae and osteophyte formation were reviewed on X-ray and CT, and were converted to the semi-quantitative degeneration score according to the Goffin method. The correlation between Nurick score or degeneration score and the age at operation or fusion levels was compared by Spearman correlation coefficients. The cervical canal sizes of adjacent level and remote level on MRI were reviewed and compared with each other by t test. Results The follow-up period was 3 to 10 years, 6.9 years on average. There was difference in the Nurick score between the 6th week after operation (1.07 ± 0.84) and the later follow up (1.92 ± 1.28) by rank test (P lt; 0.05). There was no correlation between the Nurick score change and the age at operation (r = 0.21, P gt; 0.05) or fused levels(r = 0.30, P gt; 0.05) by Spearman correlation coefficients. There was obvious difference in degeneration score between the 6th week after operation (0.73 ± 0.67) and the later follow up (1.58 ± 1.06), (P lt; 0.01). There was no correlation between the degeneration score change and the age at operation (r = 0.35, P gt; 0.05) or fusion levels (r = 0.38, P gt; 0.05) by Spearman correlation coefficients. The cervical canal size reductions were (1.7 ± 1.1) mm at superioradjacent level, (1.2 ± 0.6) mm at inferior adjacent level and (0.30 ± 0.68) mm at remote level. There was obvious difference between superior or inferior and remote level by t test (P lt; 0.01). The adjacent level developed prominent degeneration together with nerve function change after the fusion operation and displayed correlation between degeneration and nerve function change(r = 0.41, P lt; 0.05). Conclusion The adjacent-segment disease after interbody fusion is produced by multiple factors. The natural progression in adjacent disc, biomechanical natural change resulting from interbody fusion, destruction to l igament structure in front of cervical vertebrae by operation, and bone graft model are important factors not to be ignored.
OBJECTIVE: To investigate the etiology, pathological mechanism and treatment of cervical fracture-dislocation without spinal cord injury. METHODS: Nine patients with cervical fracture-dislocation without spinal cord injury were male and aged 22 to 63 years. Based on the clinical symptoms and roentgenographic changes, the injury mechanism was analyzed; and the pathological characteristics and treatment principle were put forward. RESULTS: Anterior reduction was employed in all 9 cases. Eight cases were reduced completely while 1 case was reduced partially. After following up 1 to 3 years, 7 cases recovered completely and the other 2 cases relieved their symptoms obviously. No nervous symptoms aggravated during the following-up period. CONCLUSION: Fracture-dislocation of the cervical spine without spinal cord injury has special pathological mechanism. The surgical intervention is needed for solid fixation and complete decompression without any delayed neurosymptoms.
ObjectiveTo summarize the research progress in clinic, development, and genetics of the Klippel-Feil syndrome and its primary ear deformity. MethodsThe related 1iterature at home and abroad concerning the Klippel-Feil syndrome with ear malformation was reviewed, analyzed, and summarized. ResultsThe clinical manifestation and classification of Klippel-Feil syndrome are complicated. As one of the most important accompany malformations, ear deformity mainly leads to hearing impairment and abnormal appearance. However, it is still unclear exactly how the ear deformity forms in Klippel-Feil syndrome, and there is little deep study on the internal connection between the ear deformity and other malformations. The premise for the treatment of Klippel-Feil syndrome includes accurate diagnoses and comprehensive disease assessment, and multidisciplinary collaboration will be the important direction of clinical practice in the future. ConclusionEar malformation is one of the most important congenital dysplasias in the Klippel-Feil syndrome. Its etiology should be based on research in the development and genetic mechanism. And its diagnosis and treatment should be followed by multidisciplinary collaboration. It is important to pay attention to identifying with ear malformation in other syndromes as well.
ObjectiveTo evaluate the effectiveness of posterior cervical decompressive laminectomy and lateral mass screw fixation combined with foraminotomy for treating cervical radiculo-myelopathy. MethodsBetween January 2010 and January 2012, 58 patients with cervical radiculo-myelopathy were treated by posterior cervical decompressive laminectomy and lateral mass screw fixation combined with foraminotomy. There were 31 males and 27 females, with an average age of 52.7 years (range, 41-72 years). The mean disease course was 5.4 years (range, 3-15 years). The preoperative Japanese Orthopaedic Association (JOA) score was 7.8±1.3, and visual analogue scale (VAS) score was 6.8±1.7. There were 37 cases of inter-vertebral disc herniation and ligamentum flavum hypertrophy, 11 cases of vertebral osteophyte formation with the osteophyte spinal canal occupational ratio of 51.7%±18.1%, and 10 cases of inter-vertebral disc herination with cervical instability. Preoperative cervical curvature was (-5.5±12.5)°. The fixed segments included C3-7 in 29 cases, C4-7 in 19 cases, and C3-6 in 10 cases. Foraminotomy was performed in 135 nerve foramina (mean, 2.33 foramina). ResultsThe mean operation time was 204 minutes (range, 167-260 minutes), and the mean blood loss was 273 mL (range, 210-378 mL). No injury of vertebral artery or nerve root occurred during operation. Postoperative subcutaneous hematoma and cervical axial pain occurred in 1 case and 8 cases, respectively; and no nerve root palsy was observed. The patients were followed up 2.1-4.3 years (mean, 3.4 years). The postoperative JOA score was significantly increased to 14.1±1.7 (t=-27.672, P=0.000), with an improvement rate of 68.5%±21.9%. Postoperative VAS score was significantly decreased to 2.1±1.1 (t=15.168, P=0.000). The imaging examination showed adjacent segmental degeneration in 1 patient, who had no clinical symptom. There was no screw loosening or pseudoarthrosis formation during follow-up. The cervical curvature was (13.6±5.1)° at 5 days and was (13.2±4.8)° at 2 years, showing significant difference when compared with preoperative one (P < 0.05). The osteophyte spinal canal occupational ratio was 36.5%±10.4% at 2 years, showing significant difference when compared with preoperative one (t=6.921, P=0.000). ConclusionThe procedure of posterior cervical decompressive laminectomy and lateral mass screw fixation combined with foraminotomy is effect in treating cervical radiculo-myelopathy. The spinal cord and nerve root can be adequately decompressed by laminectomy and foraminotomy. The lateral mass screw fixation can correct the cervical curvature and further reduce the tension to spinal cord.
ObjectiveTo study the efficacy of anterior cervical Vectra-t dynamic plate and titanium mesh for cervical spondylosis. MethodsA retrospectively analysis involving 20 cases (44 sections) from June 2010 to October 2012 was performed in the department of orthopaedic in the West China Hospital of Sichuan University. All patients received the operation of anterior cervical vertebral resection decompression, titanium mesh and bone graft, and Vectra-T plate. The data of the JOA scores, cervical curvature, the conditions of vertebral body fusion after bone graft and the situation of titanium mesh subsidence were all collected. Statistical analysis were performed using SPSS 19.0 software. Resultsa) All the 20 cases received a 12-to 30-month follow-up. The results of statistical analysis showed that:the JOA scores were as follows:7.68±1.66 for preoperative, 10.91±1.97 for after surgery and 12.74±1.27 for the endpoint of follow-up, and significant differences were found between these scores (P < 0.05). b) There was no loose of screw or plate. The local cervical angle and regional cervical angle were improved after surgery. In the 44 segments of fusion, 43 segments fused within 6 months, one of the segment delayed to fuse 12 months after surgery. c) The subsidence of titanium mesh were 2.7±2.7 mm on average in 3 months after surgery, 3.6±1.0 mm on average in 6 months after surgery, 3.9±1.2 mm on average in 12 months after surgery and 4.0±1.2 mm on average in last follow-up. Titanium mesh subsidence mainly concentrated in the postoperative period of 6 months. After six months of titanium mesh subsidence was no longer apparent. ConclusionThe application of Vectra-T dynamic plate can effectively improve the curvature of the cerical sagittal position, prevent protrusion deformity, reduce the related complications after bone graft, effectively avoid the stress shelter in the static plate, andspromote the fusion between the cervical vertebral bodies. However, the long-term curative effects are still needed to be assessed by large sample randomized controlled trials with long-term follow-up.
ObjectiveTo study the effectiveness and safety of simply anterior approach for lower cervical spine fracture dislocation (Allen-Ferguson II or III type) without spinal cord injury. MethodsTwenty-five patients with lower cervical spine fracture dislocation (Allen-Ferguson II or III type) without spinal cord injury were treated between June 2013 and June 2015. There were 17 males and 8 females with an average age of 41.2 years (range, 31-57 years). Injury was caused by falling from height in 11 cases, by bruise in 5 cases, by crash of heavy object in 6 cases, and by traffic accident in 3 cases. There were 24 cases of fresh fractures and 1 case of old fracture. According to the Frankel grading criteria, 19 cases were rated as grade E and 6 cases as grade D. The injured levels included C4, 5 in 5 cases, C5, 6 in 14 cases, and C6, 7 in 6 cases. Unilateral locked-facet joint was observed in 9 cases, and bilateral locked-facet joint in 16 cases. The operation time, intraoperative blood loss, and surgical complications were recorded; the Odom standard was used to evaluate the effectiveness. The Cobb angle and D-value (the degree of cervical kyphosis or lordosis) were measured on the X-ray film, the bone graft fusion rate was recorded. ResultsThe operation was successfully completed in 25 patients; the operation time was 66 to 115 minutes, the intraoperative blood loss was 80 to 220 mL. The postoperative follow-up time was 12 to 36 months (mean, 19.3 months). Postoperative temporary dysphagia occurred in 1 case, and pain at donor site in 2 cases; there were no complications of spinal cord injury, hematoma, hoarse, and esophageal fistula. The nerve function was improved from preoperative grade D to postoperative grade E at 3 months. The X-ray films showed bone graft fusion; there was no loss of intervertebral height or loosening of internal fixation. At 3 months after operation, the effectiveness was excellent in 18 cases, good in 6 cases, and fair in 1 case, and the excellent and good rate was 96.0%. The postoperative Cobb angle and the D value were significantly improved when compared with preoperative ones (P < 0.05). ConclusionSimple anterior approach has the advantages of good effectiveness, small trauma, and fast recovery for treating lower cervical spine fracture dislocation (Allen-Ferguson II or III type) without spinal cord injury.
ObjectiveTo investigate the classification and clinical value of unilateral cervical lateral mass fracture (C3-7).MethodsFrom January 2008 to December 2017, 68 patients with unilateral cervical lateral mass fracture who had received treatment in Affiliated Hospital of Southwest Medical University, were included. According to the position of fracture, the fractures were classified into three types: articular process fractures (type A), isthmus fracture (type B), and comminution (type C). Two subtypes of articular process fractures were type A1 and type A2. Type A1 refered to articular process fracture with no or slight displacement. Type A2 refered to articular process fractures result in foraminal stenosis and nerve root compression. Single-level anterior cervical disectomy and fusion (ACDF) or anterior cervical corpectomy and fusion (ACCF) or conservative treatment was used in type A1. Posterior decompression, fixation and fusion or the method of posterior decompression associated with ACDF were suited to A2. Single-level ACDF was used in type B as well. Type C underwent two-level ACDF or ACCF or posterior procedure.ResultsThere were 35 cases of Type A1, of which 31 patients underwent single-level ACDF, 2 patients underwent ACCF, and 2 patients received conservative treatment, but one of the two underwent ACDF due to delayed cervical instability. Among the 7 cases of type A2, 4 underwent posterior foraminal decompression and posterior fusion with pedicure screw fixation, 2 underwent single-level ACDF and posterior decompression, and 1 underwent single section ACDF and posterior decompression combined with pedical screw fixation. Type C accounted for 21 cases of all targets. Fourteen performed two-level ACDF, 6 performed ACCF, and 1 performed posterior fixation with pedicure screw and expansive open-door laminoplasty. Six patients showed postoperative complications, including C5 root palsy in one case, incision hematoma in two and pulmonary infection in three. There were no case with incision infection or aggravating nervous injury. Sixty-two patients (91.2%) were followed up with a mean duration of 14 months. All the patients obtained bony fusion and no internal fixation failure or kyphosis was found.ConclusionsAccording to fracture position and CT, the unilateral cervical lateral mass fracture can be classified as type A1, type A2, type B, and type C. A satisfied clinical result can be obtained when choosing an appropriate treatment in accordance with different fracture types.
ObjectiveTo investigate the effect of modified lateral mass screws implantation strategy on axial symptoms in cervical expansive open-door laminoplasty. MethodsA clinical data of 166 patients, who underwent cervical expansive open-door laminoplasty between August 2011 and July 2016 and met the selection criteria, was retrospective analyzed. Among them, 81 patients were admitted before August 2014 using the traditional mini-plate placement and lateral mass screws implantation strategy (control group), and 85 patients were admitted after August 2014 using modified lateral mass screws implantation strategy (modified group). There was no significant difference in the gender composition, age, clinical diagnosis, disease duration, diseased segment, and preoperative Japanese Orthopaedic Association (JOA) score, pain visual analogue scale (VAS) score, Neck Disability Index (NDI), cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, and Pavlov’s value between the two groups (P>0.05). The operation time, intraoperative blood loss, the number of facet joints penetrated by lateral mass screws, effectiveness evaluation indexes (JOA score and improvement rate, VAS score, NDI), imaging evaluation indexes (cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, Pavlov’s value, and lamina open angle), and complications were recorded and compared between the two groups.ResultsThe modified group had shorter operation time and lower intraoperative blood loss than the control group (P<0.05). There were 121 (29.9%, 121/405) and 10 (2.4%, 10/417) facet joints penetrated by lateral mass screws in control and modified groups, respectively; and the difference in incidence was significant (χ2=115.797, P=0.000). Eighteen patients in control group had 3 or more facet joints penetrated while no patients in modified group suffered 3 or more facet joint penetrated. The difference between the two groups was significant (P=0.000). All patients were followed up, the follow-up time was (28.7±4.9) months in modified group and (42.4±10.7) months in control group, showing significant difference (t=10.718, P=0.000). The JOA score, VAS score, and NDI at last follow-up of the two groups were significantly improved compared with preoperative (P<0.05); there was no significant difference in JOA score and improvement rate and VAS score between the two groups (P>0.05), but the NDI was significantly lower in modified group than in control group (P<0.05). There were significant differences in cervical curvature and range of motion, spinal canal diameter, Pavlov’s value, and cross-sectional areas at last follow-up when compared with those before operation in both groups (P<0.05). There was no significant difference in the above indicators and lamina open angle between the two groups (P>0.05). The modified group has a relative lower axial symptom rate (23/85, 27.1%) than the control group (27/81, 33.3%), but the difference was not significant (Z=−1.446, P=0.148). There was no significant differences between the two groups in the incidences of C5 nerve root palsy, cerebrospinal fluid leakage, wound infection, and lung or urinary tract infection (P>0.05). ConclusionIn the cervical expansive open-door laminoplasty, the modified lateral mass screws implantation strategy can effectively reduce the risk of lateral mass screw penetrated to the cervical facet joints, and thus has a positive significance in avoiding the axial symptoms caused by facet joint destruction.