Comparison of Postoperative Pain and Surgical Outcomes Between Three Types of Modified Muscle-Sparing Laminoplasty and Conventional Laminoplasty for Multilevel Degenerative Cervical Myelopathy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: This study aimed to compare postoperative pain and surgical outcomes of open-door laminoplasty (LP) and three types of muscle-sparing laminoplasties, namely unilateral muscle-preservation laminoplasty (UL), spinous process splitting double-door laminoplasty (DL) and intermuscular "raising roof" laminoplasty (RL) for multilevel degenerative cervical myelopathy (MDCM). METHODS: Consecutive MDCM patients underwent LP or modified laminoplasties (UL, DL, RL) in 2022 were enrolled. Patients' preoperative baseline data and surgical characteristics were collected. Postoperative transient pain (TP), the axial pain and Japanese Orthopedic Association (JOA) score and neck disability index (NDI) at 6-month and 12-month follow-up were documented. RESULTS: A total of 154 MDCM patients were included and a 12-month follow-up was completed for 148 patients (LP: 36, UL:39, DL: 37, RL:36). No significant difference was observed in the baseline data. Four groups presented favorable and comparable surgical outcome. The RL group reported significantly the least severe TP on the first three days following surgery. However, no significant difference was found in the axial pain and axial symptoms at both follow-ups. After regression analysis, RL group exhibited significantly better efficacy in alleviating Day-1 TP (P = 0.047) and 6-month axial pain (P = 0.040). However, this superiority was not observed at 12-month follow-up. CONCLUSION: All the three muscle-sparing laminoplasty procedures showed similar short-term surgical outcomes compared to LP. The RL procedure demonstrated superiority in alleviating TP and 6-month axial pain compared to LP. The RL and DL groups showed less C5 palsy compared to LP.

Finite element analysis of a new preoperative traction for cervical kyphosis: suspensory traction.

A finite element model of cervical kyphosis was established to analyze the stress of cervical spine under suspensory traction and to explore the mechanism and effect of it. A patient with typical cervical kyphosis (C2-C5) underwent CT scan imaging, and 3D slicer was used to reconstruct the C2 to T2 vertebral bodies. The reconstructed data was imported into Hypermesh 2020 and Abaqus 2017 for meshing and finite element analysis. The changes of the kyphotic angle and the von Mises stress on the annulus fibrosus of each intervertebral disc and ligaments were analyzed under suspensory traction conditions. With the increase of suspensory traction weight, the overall kyphosis of cervical spine showed a decreasing trend. The correction of kyphosis was mainly contributed by the change of kyphotic segments. The kyphotic angle of C2-C5 was corrected from 45° to 13° finally. In cervical intervertebral discs, the stress was concentrated to anterior and posterior part, except for C4-5. The stress of the anterior longitudinal ligament (ALL) decreased from the rostral to the caudal, and the high level von Mises stress of the kyphotic segments appeared at C2-C3, C3-C4, and C4-C5. The roles of the other ligaments were not obvious. The kyphotic angle was significantly reduced by the suspensory traction. Shear effect due to the high von Mises stress in the anterior and posterior parts of annulus fibrosus and the tension on the anterior longitudinal ligament play a role in the correction of cervical kyphosis.

Classification and prognostic factors of patients with cervical spondylotic myelopathy after surgical treatment: a cluster analysis.

Identifying potential prognostic factors of CSM patients could improve doctors' clinical decision-making ability. The study retrospectively collected the baseline data of population characteristics, clinical symptoms, physical examination, neurological function and quality of life scores of patients with CSM based on the clinical big data research platform. The modified Japanese Orthopedic Association (mJOA) score and SF-36 score from the short-term follow-up data were entered into the cluster analysis to characterize postoperative residual symptoms and quality of life. Four clusters were yielded representing different patterns of residual symptoms and quality of patients' life. Patients in cluster 2 (mJOA RR 55.8%) and cluster 4 (mJOA RR 55.8%) were substantially improved and had better quality of life. The influencing factors for the better prognosis of patients in cluster 2 were young age (50.1 ± 11.8), low incidence of disabling claudication (5.0%) and pathological signs (63.0%), and good preoperative SF36-physiological function score (73.1 ± 24.0) and mJOA socre (13.7 ± 2.8); and in cluster 4 the main influencing factor was low incidence of neck and shoulder pain (11.7%). We preliminarily verified the reliability of the clustering results with the long-term follow-up data and identified the preoperative features that were helpful to predict the prognosis of the patients. This study provided reference and research basis for further study with a larger sample data, extracting more patient features, selecting more follow-up nodes, and improving clustering algorithm.

Congenital Cervical Scoliosis Treated with Concave Side Distraction with Three-Dimensional Printed Titanium Cage.

STUDY DESIGN: Single-center, retrospective study. OBJECTIVE: Hemivertebra resection is the only treatment option for congenital cervical scoliosis (CCS). However, this procedure is complex and technically demanding. It often requires a considerably long operation, and there is substantial intraoperative bleeding. Therefore, we have attempted to treat CCS with a concave side distraction comprising a three-dimensional (3D) printed titanium cage. The purpose of this study is to evaluate the safety and efficacy of this technique for the treatment of patients with CCS. METHODS: A series of 22 patients with CCS who underwent a concave side distraction technique between 2019 and 2021 were retrospectively reviewed and analyzed. Radiological measurements included the Cobb angle of the distraction segments, the kyphosis angle, the range of movement, and the distraction correction angle. Student's t-test and Spearman correlation analysis were used for statistical analysis. p < 0.05 was considered statistically significant. RESULTS: The study included 12 males and 10 females whose ages ranged from 6 to 14 years old (9.8 ± 2.1 years old). Follow-up times ranged from 15 to 30 months (25.8 ± 3.6 months). Among 22 patients, two patients developed a postoperative C5 nerve root palsy and recovered after being treated with conservative treatment for 6 months. The duration of surgery ranged from 229 to 756 min (389 ± 112 min), and the estimated volume of blood loss ranged from 100 to 600mL (235 ± 121 mL). The coronal Cobb angle (p < 0.001), kyphosis angle (p < 0.05), and range of movement (p < 0.001) between the last follow-up and preoperative period were significantly different. A total of 28 segments were distracted, and the Cobb angle of the distraction segment ranged from 2.4 to 14.1° (8.5 ± 3.0°). There were six upper cervical spines (8.9 ± 1.9°) and 22 lower cervical spines (8.4 ± 3.2°) with no significant difference between them (p = 0.130). In addition, there was no correlation between the angle of the concave side distraction and patients' age (r = 0.018, p = 0.315). The fusion was solid between the bone and the customized 3D-printed pore metal cage at the final follow-up. CONCLUSION: The concave side distraction comprising a customized 3D-printed titanium cage implantation can provide satisfactory correction results and is a safe and reliable procedure for treating CCS.

Predictive Value of Preoperative Short Form-36 Survey Scale for Postoperative Axial Neck Pain in Patients With Degenerative Cervical Myelopathy.

STUDY DESIGN: Prospective observational study. OBJECTIVE: To evaluate the predictive value of the preoperative Short Form-36 survey (SF-36) scale for postoperative axial neck pain (ANP) in patients with degenerative cervical myelopathy (DCM) who underwent anterior cervical decompression and fusion (ACDF) surgery. METHODS: This study enrolled patients with DCM who underwent ACDF surgery at author's Hospital between May 2010 and June 2016. RESULTS: Out of 126 eligible patients, 122 completed the 3-month follow-up and 117 completed the 1-year follow-up. The results showed that the preoperative social functioning (SF) subscale score of the SF-36 scale was significantly lower in patients with moderate-to-severe postoperative ANP than in those with no or mild postoperative ANP at both follow-up timepoints (P < .05). ACDF at C4-5 level resulted in a higher ANP rate than ACDF at C5-6 or C6-7 level, both at 3-month (P = .019) and 1-year (P = .004) follow-up. Multivariate logistic regression analysis confirmed that the preoperative social functioning subscale score was an independent risk factor for moderate-to-severe postoperative ANP at 3 months and 1 year after surgery, and preoperative NRS was an independent risk factor at 1-year follow-up. No other demographic, clinical, or radiographic factors were found to be associated with postoperative ANP severity (P < .05). CONCLUSIONS: Preoperative social functioning subscale score of SF-36 scale might be a favorable predictive tool for postoperative ANP in DCM patients who underwent ACDF surgery.

Evaluation and Comparation of a Novel Surgical Technique and Hemivertebra Resection to the Correction of Congenital Cervical Scoliosis in Lower Cervical and Cervicothoracic Spine.

OBJECTIVE: To report concave-side distraction technique to treat congenital cervical scoliosis in lower cervical and cervicothoracic spine. To evaluate and compare clinical and radiographic results of this procedure with classic hemivertebra resection procedure. METHODS: This study reviewed 29 patients in last 13 years. These patients were divided into convex-side resection group (group R) and concave-side distraction group (group D). Radiographic assessment was based on parameter changes preoperatively, postoperatively and at last follow-up. Demographic data, surgical data and complications were also evaluated and compared between the 2 groups. RESULTS: In group R, mean age was 8.9 ± 3.3 years and follow-up was 46 ± 18 months. Operation time and blood loss averaged 500 ± 100 minutes, 703 ± 367 mL. In group D, mean age was 9.9 ± 2.8 years and follow-up was 34 ± 14 months. Operation time and blood loss averaged 501 ± 112 minutes, 374 ± 181 mL. Structural Cobb angle was corrected from 29.4° ± 12.5° to 5.3° (2.1°-18.1°) (p = 0.001) and 33.7° ± 14.1° to 12.8° ± 11.4° (p < 0.001) in groups R and D. Compensatory Cobb angle had a spontaneous correction rate of 59.6% (40.0%-80.8%) and 59.7% ± 23.0% in groups R and D. Mandibular incline, clavicle angle and spine coronal balance were significantly improved at last follow-up in both groups. All correction rates were not statistically different between groups. However, group D had significant less blood loss (p < 0.001) and operation time (p = 0.004) per vertebra than group R. Seven patients developed C5 nerve root palsy and recovered by 6 months of follow-up. CONCLUSION: Both surgical procedures are safe and effective in correcting congenital cervical scoliosis. But concave-side distraction technique has less blood loss and time-consuming during surgery, which provides a better option for the treatment of congenital cervical scoliosis.

Prevalence and Risk Factors of Surgical Treatment for Klippel-Feil Syndrome.

Background: Recently, there have been some reports on surgical treatment for Klippel-Feil syndrome, but the prevalence and risk factors of surgery have not been well evaluated. This study sought to find the prevalence and potential risk factors of surgical treatment. Methods: A retrospective radiographic review of 718 Klippel-Feil syndrome patients seen at Peking University Third Hospital from January 2010 to October 2017 was performed. Parameters included age, gender, deformity, cervical instability, Samartzis classification, and surgical treatment. Based on the surgical treatment they received, patients were divided into a surgery group and a non-surgery group. Prevalence and possible risk factors of surgical treatment were assessed. Results: A total of 718 Klippel-Feil syndrome patients, including 327 men and 391 women, with an average age of 46.8 years were enrolled. According to the Samartzis classification scheme, 621 cases (86.5%) were classified as type I, 48 cases (6.7%) were classified as type II, and 49 cases (6.8%) were classified as type III, respectively. The most commonly fused segments were C2-3 (54.9%) and C5-6 (9.3%). Of all 718 patients, 133 (18.5%) patients underwent surgical treatment, mainly via the posterior approach (69.9%). The clinical factors included age, gender, deformity, instability, and Samartzis classification. Men were more likely to require surgical treatment (p < 0.001). Patients with instability (p < 0.001) or patients with deformity (p = 0.004) were also more likely to undergo surgery. All three of these variables were included in the binary regression analysis. Finally, gender (p < 0.001) and unstable joints (p < 0.001) were identified to be independently associated with surgical treatment. Gender was the most important risk factor with men being 2.39 times more likely to have surgical treatment, while patients with instability were 2.31 times more likely to receive surgery. Conclusion: The prevalence of patients with Klippel-Feil syndrome requiring surgery was 18.5%, with the majority undergoing posterior cervical surgery. Gender and instability were indemnified as independent risk factors leading to surgical treatment.

Single-level Cervical Arthroplasty with Prodisc-C Vivo Artificial Disc: Five-year Follow-up Results From One Center.

STUDY DESIGN: Retrospective study. OBJECTIVE: The aim of this study was to evaluate the long-term clinical and radiographic outcomes of cervical arthroplasty using the ProDisc-C Vivo prosthesis. SUMMARY OF BACKGROUND DATA: Previous reports have shown that cervical arthroplasty with ProDisc-C artificial disc has acceptable clinical outcomes at 5-year and 10-year follow-ups. METHODS: Clinical and radiographic evaluations, including dynamic flexion-extension lateral images, were performed at baseline and at the 5-year follow-up. RESULTS: Twenty-eight patients who underwent single-level ProDisc-C Vivo arthroplasty were followed-up for a mean period of 65 months. The range of motion at the operated level was 8.9°â€Š±â€Š2.3° at baseline and 8.3°â€Š±â€Š4.8° at the final follow-up (P  = 0.494). Fourteen of 28 levels (50%) developed heterotopic ossification (HO). According to McAfee's classification, one level was classified as grade I, nine levels as grade II, two levels as grade III, and two levels as grade IV. Only four of 28 levels (14.3%) had severe HO. Among patients with cervical spondylotic myelopathy, mJOA score was 13.9 ±â€Š2.5° at baseline and 15.9°â€Š±â€Š1.0° at the final follow-up (P  = 0.001 < 0.05). Among patients with cervical spondylotic radiculopathy, Visual Analog Scale (VAS) neck and shoulder was 5.4 ±â€Š1.4° at baseline and 0.7°â€Š±â€Š1.2° at the final follow-up (p = 0.000 < 0.05), VAS arm was 5.1 ±â€Š2.8° at baseline and 0.5°â€Š±â€Š1.2° at the final follow-up (P  = 0.000 < 0.05). A total of 49 adjacent segments were observed and 13 (26.5%) had adjacent segment degeneration. No patient developed recurrent cervical radiculopathy or myelopathy due to adjacent segment disease. No patient underwent re-operation. CONCLUSION: ProDisc-C Vivo arthroplasty had satisfactory clinical and radiographic outcomes at 5-year follow-up.Level of Evidence: 4.

Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire as an outcome measure for ossification of posterior longitudinal ligament patients in East Asia: an investigation of reliability, validity, and responsiveness.

BACKGROUND: The surgical outcomes of individual patient with ossification of the posterior longitudinal ligament (OPLL) can vary depending on various patient-related factors. Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) is a well-developed tool for outcome measurement and considers both disease-specific and general health aspects. This study aimed to investigate the reliability, validity, and responsiveness of the JOACMEQ in patients with OPLL in mainland China and to compare post-operative outcomes of OPLL patients between mainland China and Japan. METHODS: This multicenter trial was performed between July 2009 and June 2019. The procedure for the JOACMEQ translation followed Beaton's guidelines. All patients enrolled were diagnosed with OPLL and had completed the JOACMEQ, the modified Japanese Orthopaedic Association (mJOA) scale, and the 36-Item Short Form Health Survey (SF-36) before and after surgery. The reliability (Cronbach's α and Pearson's correlation), construct validity (factor analysis), concurrent validity (Spearman's correlation with SF-36) and responsiveness (effect sizes) of JOACMEQ were evaluated. A mixed-model analytic approach was used to analyze differences in postoperative outcomes between the 2 countries. RESULTS: Ninety-one patients from mainland China and ninety-one patients from Japan were recruited. JOACMEQ showed satisfactory internal consistency (Cronbach's α=0.75). In test-retest reliability evaluation, except for the bladder function domain, the JOACMEQ domains had good test-retest reliability (0.89-0.96). In factor analysis, most of the items (19/24) were well clustered. Regarding clinical validity, all 5 domains were found to have moderate correlations with the physical component summary (PCS) of SF-36 (r=0.25-0.50), and the bladder function and quality of life domains also had moderate correlations (r=0.25-0.50) with the mental component summary (MCS) of SF-36. JOACMEQ showed a variable responsiveness in different domains (effect size =0.17-0.84; standardized response means =0.15-0.85). Regarding postoperative improvements in the JOACMEQ score, mixed-model analysis revealed a significant difference in the quality of life domain between Chinese and Japanese patients (16.0±18.7 vs. 7.8±17.7, P<0.05). CONCLUSIONS: JOACMEQ generally shows good reliability, good validity and mild responsiveness, and can identify the post-operative improvements in patients with OPLL in mainland China. Chinese OPLL patients showed a significantly larger improvement in postoperative quality of life compared to their Japanese counterparts.

Vertebral Artery Variation in Patients With Congenital Cervical Scoliosis: An Anatomical Study Based on Radiological Findings.

STUDY DESIGN: Observational, anatomical, radiological study. OBJECTIVE: The aim of this study was to explore the incidence and type of vertebral artery (VA) variation in patients with congenital cervical scoliosis and approach their clinical importance during surgery. SUMMARY OF BACKGROUND DATA: Congenital scoliosis of the cervical spine is usually sporadic and caused by a variety of bone structural anomalies. Most of the cases remain asymptomatic. Surgical intervention is the main management for patients with neurological compromise or with cosmetic demands. The operation involved more screw insertion and osteotomy than the regular degenerative cases. The incidence and pattern of VA variants in these patients have not been reported. METHODS: Patients with congenital cervical scoliosis treated in our department were reviewed. We measured Cobb angle of cervical spine. We observed bilateral VAs and recorded variants. We measured their diameter in each segment through CT angiography. The bilateral diameter in each patient was then compared respectively. RESULT: There is a total of 44 patients enrolled. The incidence of VA variation was 41% (18/44). Fifty percent (22/44) of patients had the dominant VA with no difference between concave side and convex side. Patients with a dominant VA had a larger Cobb angle than those who had not (30.25° vs. 23.24°, P < 0.05). The courses of VA were abnormal in 18 patients. Two patients had unilateral variant in V1 segment. Twelve patients had variants in V2 segment. Eight patients had variants in V3 segment. Three patients had VA variants in multiple sites. CONCLUSION: In patients with congenital cervical scoliosis, the dominance of VA is not related to the convex side or concave side, but patients with a dominance of VA have a larger Cobb angle. The incidence of variant in V2 and V3 segment is higher. A thorough evaluation of bilateral VAs is required before surgery. Extra cautions must be taken during surgery.Level of Evidence: 5.

A prospective randomized cohort study on 3D-printed artificial vertebral body in single-level anterior cervical corpectomy for cervical spondylotic myelopathy.

BACKGROUND: This was a prospective randomized cohort study aiming at examining the safety and efficacy of artificial vertebral body (AVB) fabricated by electron beam melting (EBM) in comparison to conventional titanium mesh cage (TMC) used in single-level anterior cervical corpectomy and fusion (SL-ACCF). METHODS: Forty patients with cervical spondylotic myelopathy (CSM) underwent SL-ACCF using either the EBM-AVB or the TMC. Patients were evaluated for their demographics, radiological characteristics, neurologic function [using the Japanese Orthopaedic Association (JOA) scale], and health-related quality-of-life (HRQoL) aspects [using the Short Form 36 (SF-36)] before and after the surgery and comparison was made between the two groups both at baseline and the last follow-up. The Student t-text, paired-sample t-text, and Fisher's exact test were used when appropriate to detect any statistical significance at the level of α=0.05. RESULTS: Post-operative recovery was uneventful for all patients and no revision surgery was required. There were no significant differences between the EBM-AVB group and the TMC group at baseline. Patients in both groups demonstrated significant improvement in cervical alignment, JOA score, and SF-36 score after the surgery. Six months post-operatively, patients in the EBM-AVB group were found to have significantly less loss of fusion height and lower incidence for severe implant subsidence compared with the TMC group. Patients in the two groups were comparable at the last follow-up regarding their rate of fusion, cervical alignment, JOA recovery rate, SF-36 score, and by Odom's criteria. CONCLUSIONS: For CSM patients undergoing SL-ACCF, the EBM-AVB group demonstrated comparable outcomes regarding patient cervical alignment, neurologic function, and HRQoL in comparison with the TMC group. Furthermore, the use of EBM-AVB was associated with decreased loss of the height of the fusion mass and a lower rate for severe implant subsidence.

Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) in mainland China: an investigation of reliability, validity, and responsiveness.

BACKGROUND: The aim of this study is to investigate the reliability, validity, and responsiveness of JOACMEQ for CSM patients in mainland China. METHODS: A retrospective review was performed on 91 patients with CSM in our hospital from March 2015 to June 2015. Patients completed the JOACMEQ, the mJOA and the SF-36 questionnaires during the process. Cronbach's α was used to evaluate the internal consistency reliability, and test-retest reliability was checked. An exploratory factor analysis was used to determine the correlations among the JOACMEQ questions and the construct validity. The concurrent validity was assessed by Spearman correlation coefficient. The internal responsiveness was determined by effect sizes and standardized response means. External responsiveness was determined by the area under the receiver operating characteristic curve on the basis of the Youden Index. RESULTS: The mean age of patients was 57.61 years old. The mean follow-up was 24 months. JOACMEQ showed a good internal consistency (Cronbach's α, 0.897). Test-retest reliability showing good result (Pearson's correlation, 0.695-0.905). Our data were amenable to factor analysis (KMO = 0.816, Bartlett's test, χ2(45) = 1199.99, p < 0.001), and five factors above 1 were strongly loaded and clustered for each of the five factors. Comparing the scales preoperative to those 2 years postoperative, the average scores of the subscales all increased, and both the ES and SRM showing satisfied responsiveness. In external responsiveness analysis, the recovery rate a appeared to be most responsive to post-operative improvement. CONCLUSIONS: The Simplified Chinese version of JOACMEQ was well-developed with great reliability and sensitive responsiveness. Our study demonstrated that JOACMEQ has content psychometric properties to identify postoperative improvements in CSM patients.

Quantitative analysis of the correlation between preoperative cervical degeneration and postoperative heterotopic ossification after cervical disc replacement: minimum 10-year follow-up data.

OBJECTIVE: The authors aimed to identify factors that may be useful for quantifying the amount of degenerative change in preoperative patients to identify ideal candidates for cervical disc replacement (CDR) in patients with a minimum of 10 years of follow-up data. METHODS: During the period from December 2003 to August 2008, 54 patients underwent CDR with a Bryan cervical disc prosthesis performed by the same group of surgeons, and all of the patients in this group with at least 10 years of follow-up data were enrolled in this retrospective analysis of cases. Postoperative bone formation was graded in radiographic images by using the McAfee classification for heterotopic ossification. Preoperative degeneration was evaluated in radiographs based on a quantitative scoring system. After univariate analysis, the authors performed multifactor logistic regression analysis to identify significant factors. To determine the cutoff points for the significant factors, a receiver operating characteristic (ROC) curve analysis was conducted. RESULTS: Study patients had a mean age of 43.6 years and an average follow-up period of 120.3 months. The patients as a group had a 68.2% overall incidence of bone formation. Based on univariate analysis results, data for patient sex, disc height, and the presence of anterior osteophytes and endplate sclerosis were included in the multivariate analysis. According to the analysis results, the identified independent risk factors for postoperative bone formation included disc height, the presence of anterior osteophytes, and endplate sclerosis, and according to a quantitative scoring system for degeneration of the cervical spine based on these variables, the ROC curve indicated that the optimal cutoff scores for these risk factors were 0.5, 1.5, and 1.5, respectively. CONCLUSIONS: Among the patients who were followed up for at least 10 years after CDR, the incidence of postoperative bone formation was relatively high. The study results indicate that the degree of degeneration in the target level before surgery has a positive correlation with the incidence of postoperative ossification. Rigorous indication criteria for postoperative ossification should be applied in patients for whom CDR may be a treatment option.

Effect of decompression range on decompression limit of cervical laminoplasty.

BACKGROUNDS: Cervical posterior decompression surgery is used to relieve ventral compression indirectly by incorporating a backward shift of the spinal cord, and this indirect decompression is bound to be limited. This study aimed to determine the decompression limit of posterior surgery and the effect of the decompression range. METHODS: We retrospectively reviewed the data of 129 patients who underwent cervical open-door laminoplasty through 2008 to 2012 and were grouped as follows: C4-C7 (n = 11), C3-C6 (n = 61), C3-C7 (n = 32), and C2-C7 (n = 25). According to the relative location of spinal levels within a decompression range, the type of decompression at a given level was categorized as external decompression (ED; achieved at the levels located immediately external to the decompression range margin), internal decompression (ID; achieved at the levels located immediately internal to the decompression range margin), and central decompression (CD; achieved at the levels located in the center, far from the decompression range margin). The vertebral-cord distance (VCD) was used to evaluate the decompression limit. The C2-C7 angle and VCD on post-operative magnetic resonance images were analyzed and compared between groups. The relationship between VCD and decompression type was analyzed. Moreover, the relationship between the magnitude of the ventral compressive factor and the probability of post-operative residual compression at each level for different decompression ranges was studied. RESULTS: There was no significant kyphosis in cervical curvature (> -5°), and there was no significant difference among the groups (F = 2.091, P = 0.105). The VCD of a specific level depended on the decompression type of the level and followed this pattern: ED < ID < CD (P < 0.05). The decompression type of a level was sometimes affected by the decompression range. For a given magnitude of the ventral compressive factor, the probability of residual compression was lower for the group with the larger VCD at this level. CONCLUSIONS: Our study suggests that the decompression range affected the decompression limit by changing the decompression type of a particular level. For a given cervical spinal level, the decompression limit significantly varied with decompression type as follows: ED < ID < CD. CD provided maximal decompression limit for a given level. A reasonable range of decompression could be determined based on the relationship between the magnitude of the ventral compressive factor and the decompression limits achieved by different decompression ranges.

Single-level cervical arthroplasty with ProDisc-C artificial disc: 10-year follow-up results in one centre.

PURPOSE: The aim of this study was to evaluate the long-term clinical and radiographic outcomes of cervical arthroplasty using the ProDisc-C prosthesis. METHODS: Clinical and radiographic evaluations, including dynamic flexion-extension lateral images, were performed at baseline and at 10-year follow-up. RESULTS: Twenty-seven patients who had single-level ProDisc-C arthroplasty were followed up for a mean period of 123 months. The range of motion at the operated level was 8.9° ± 3.9° at baseline and 6.6° ± 3.5° at final follow-up. Twenty of 27 levels (74%) developed heterotopic ossification. According to McAfee's classification, one level was classified as grade I, four levels were classified as grade II, 12 levels were classified as grade III and three levels were classified as grade IV. Three patients developed recurrent cervical radiculopathy or myelopathy due to adjacent segment disease and received the reoperations. The reoperations included two cases of cervical arthroplasty at adjacent segments and one case of cervical laminoplasty. CONCLUSIONS: ProDisc-C arthroplasty had acceptable clinical and radiographic results at 10-year follow-up. Heterotopic ossification was common after ProDisc-C arthroplasty, which decreased the range of motion. These slides can be retrieved under Electronic Supplementary Material.

Evaluation of a combined approach to the correction of congenital cervical or cervicothoracic scoliosis.

BACKGROUND CONTEXT: An anteroposterior combined approach has been used for the treatment of congenital cervical or cervicothoracic scoliosis. However, its outcomes and surgical risks have not been clarified. PURPOSE: We analyzed the characteristics of congenital cervical and cervicothoracic scoliosis and evaluated the outcomes of an anteroposterior combined approach for its treatment. STUDY DESIGN: We carried out a retrospective clinical study of prospectively collected data. PATIENT SAMPLE: Sixteen patients were treated between 2009 and 2013. Their average age was 9.2years. OUTCOME MEASURES: Radiographic and surgical outcomes were measured and recorded. We compared morphological parameters and preoperative and postoperative results. METHODS: All patients underwent surgery with a combined approach. The following radiographic parameters were measured: head tilt (HT), mandible incline (MI), shoulder balance (SB), structural and compensatory curves, cervical lordosis, C7 central sacral vertical line (C7-CSVL) ratio, C7 sagittal vertical axis (C7-SVA) ratio, C2-C7 SVA ratio, the angle between the upper endplate of the T2 vertebra and a horizontal line (T2 tilt), gravity line ratio. Demographic and surgical data were also collected. RESULTS: On average, the duration of follow-up was 68.0 months, surgical blood loss was 675mL, and the duration of surgery was 400.5 minutes. The average correction rate was 64.9% in the structural curve and 29.5% in the compensatory curve. Statistical analysis showed that MI significantly correlated with HT and SB (p<.05). The C7-CSVL ratio correlated with the HT, MI, and SB (p<.05). The C7-SVA ratio correlated with the structural curve and cervical lordosis (p<.05), and the gravity line ratio correlated with the structural and compensatory curve, cervical lordosis, and C7-SVA ratio (p<.05). Moreover, there were correlations between the structural and compensatory curves as well as between the structural curve and cervical lordosis (p<.05). There were significant differences before and after surgery in HT, MI, and structural and compensatory curves. Four patients developed nerve root palsy after surgical correction and totally recovered by 6 months of follow-up. CONCLUSION: The combined approach is an effective surgical option for congenital cervical or cervicothoracic scoliosis. The resection of the hemivertebra cannot only improve head-neck aesthetic appearance but can also maintain the growth potential of the neck.

Delayed epidural pseudoaneurysm following cervical laminectomy and instrumentation in a patient with canal stenosis secondary to skeletal fluorosis: A case report.

RATIONALE: The typical intraoperative presentation of vertebral artery injury (VAI) usually involves profuse bleeding and requires immediate treatment. However, an occult VAI may occur intraoperatively and result in delayed life-threatening epidural pseudoaneurysm several days postoperatively. PATIENT CONCERNS: A 21-year-old man with compressive cervical myelopathy resulting from canal stenosis of skeletal fluorosis underwent decompression of C1 to C7 and instrumentation from C2 to C7. No impressive bleeding event occurred during the operation. On postoperative day 40, progressive quadriplegia developed. DIAGNOSES: Pseudoaneurysm of the VA was established by angiography. INTERVENTIONS: After occlusion of the right VA, the patient underwent hematoma clearing. OUTCOMES: Fortunately, the patient experienced significant recovery of neurologic function after the second surgery. LESSONS: From this case, we realize even in the absence of obvious signs of VAI during a cervical operation, postoperative evaluation should be mandatory for suspected bleeding events occurring at VAI-prone sites during surgery. Moreover, the bone morphological abnormality of skeletal fluorosis was determined to be the most important risk contributing to VAI in this case. The safety limits of bone removal should be determined preoperatively to avoid the effects of bone morphological abnormalities.

Progressive Bone Formation After Cervical Disc Replacement: Minimum of 5-Year Follow-up.

STUDY DESIGN: Retrospective review. OBJECTIVE: Our objective was to examine the prevalence, clinical significance, ramifications, and possible etiology of postoperative bone formation at the index level after cervical disc replacement (CDR) with a minimum of 5 years of follow-up. SUMMARY OF BACKGROUND DATA: CDR can be complicated by postoperative ossification and unwanted ankylosis at the index level, which some authors have termed "heterotopic ossification." This terminology may be inaccurate as it assumes the postoperative bone formation is unnatural and a consequence of the CDR surgery. We advocate that this phenomenon has more to do with individual patient factors rather than the surgery. METHODS: Patients who underwent Bryan CDR for cervical myelopathy or radiculopathy between 12/2003 and 8/2008 with a minimum of 5-years follow-up were analyzed. They were divided into two groups, those with and without postoperative bone formation. Patient-reported outcomes (Japanese Orthopaedic Association score, Neck Disability Index, Visual Analogue Scale for neck and arm pain) and radiographic parameters were collected pre- and postoperatively and compared between groups. RESULTS: Sixty-one patients (76 levels) were identified (mean follow-up 94.2 mo). The overall incidence of postoperative ossification was 50%. Both groups had sustained significant improvements across all patient-reported outcome measures at final follow-up. Notably, patients with more severe preoperative cervical spondylosis had higher rates of postoperative ossification (P = 0.036) and adjacent segment degeneration (P = 0.010). CONCLUSION: Although the long-term incidence of postoperative bone formation after CDR was relatively high, this did not adversely affect patient outcomes. Patients with more severe preoperative spondylosis had higher rates of postoperative ossification, suggesting that postoperative ossification at the CDR segment is likely one of progressive bone formation in individuals already predisposed to forming bone rather than one of alleged heterotopic ossification as a consequence of the surgery. LEVEL OF EVIDENCE: 3.

A new source of autograft bone for interbody fusion in anterior cervical discectomy and fusion surgery: experience in 893 cases.

PURPOSE: This study is to share our experience of a modified anterior cervical discectomy and fusion (ACDF) procedure with a new source of autograft bone for interbody fusion. METHODS: The same procedure was performed in 893 cases where autograft was obtained from the osteophytes and/or the reams of vertebrae. For each case, radiological fusion rate and clinical outcome were followed up for 3 and 12 months after surgery. RESULTS: For one to three-level ACDF, fusion rates were from 67.8% to 75.4% at 3 months follow-up, and 92% to 98.8% at 12 months follow-up. Patients' VAS, NDI, JOA and SF-36 score improve significantly at 12 months follow-up. CONCLUSION: Osteophytes and vertebral reams can be a reliable source of bone graft that leads to high fusion rate and successful clinical outcome while avoiding all the problems with the current bone grafting methods used in ACDF surgery.

Laminoplasty with lateral mass screw fixation for cervical spondylotic myelopathy in patients with athetoid cerebral palsy: A retrospective study.

Although several studies report various treatment solutions for cervical spondylotic myelopathy in patients with athetoid cerebral palsy, long-term follow-up studies are very rare. None of the reported treatment solutions represent a gold standard for this disease owing to the small number of cases and lack of long-term follow-up. This study aimed to evaluate the outcomes of laminoplasty with lateral mass screw fixation to treat cervical spondylotic myelopathy in patients with athetoid cerebral palsy from a single center.This retrospective study included 15 patients (9 male patients and 6 female patients) with athetoid cerebral palsy who underwent laminoplasty with lateral mass screw fixation for cervical spondylotic myelopathy at our hospital between March 2006 and June 2010. Demographic variables, radiographic parameters, and pre- and postoperative clinical outcomes determined by the modified Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and visual analog scale (VAS) scores were assessed.The mean follow-up time was 80.5 months. Developmental cervical spinal canal stenosis (P = 0.02) and cervical lordosis (P = 0.04) were significantly correlated with lower preoperative modified JOA scores. The mean modified JOA scores increased from 7.97 preoperatively to 12.1 postoperatively (P < 0.01). The mean VAS score decreased from 5.30 to 3.13 (P < 0.01), and the mean NDI score decreased from 31.73 to 19.93 (P < 0.01). There was a significant negative correlation between developmental cervical spinal canal stenosis and recovery rate of the modified JOA score (P = 0.01).Developmental cervical spinal canal stenosis is significantly related to neurological function in patients with athetoid cerebral palsy. Laminoplasty with lateral mass screw fixation is an effective treatment for cervical spondylotic myelopathy in patients with athetoid cerebral palsy and developmental cervical spinal canal stenosis.