Anterior corpectomy and reconstruction using dynamic cervical plate and titanium mesh cage for cervical spondylotic myelopathy: A minimum 5-year follow-up study

Cervical Vertebra Bone Quality Score Predicts Zero-Profile Anchored Spacer Interbody Fusion Cage Subsidence after Anterior Cervical Diskectomy and Fusion: A Retrospective Study

STUDY DESIGN

Retrospective study.

OBJECTIVE

This retrospective study primary focus is to investigate the relationship between the C-VBQ score and the occurrence of postoperative zero-profile anchored spacer (ROI-C) interbody fusion cage subsidence. Additionally, we aim to evaluate the predictive efficacy of the C-VBQ scoring system for subsidence in the context of ACDF with the ROI-C.

METHODS

Patients who underwent ACDF with the ROI-C cage at our hospital between January 2016 and December 2022 were included in this study. Univariate analysis and multivariate logistic regression were employed to identify independent risk factors associated with ROI-C cage subsidence after ACDF. Pearson correlation analysis was utilized to assess the correlation between the C-VBQ score and the height of ROI-C cage subsidence.

RESULTS

A total of 102 patients underwent ACDF with ROI-C in our hospital were included in this study. Univariate analysis showed that age (P = 0.021) and C-VBQ score (P < 0.001) were the influencing factors of cage subsidence. Pearson correlation analysis showed that there was a significant positive correlation between the subsidence height of ROI-C cage and C-VBQ (r = 0.55, P < 0.01). Multivariate binary logistic regression analysis showed that C-VBQ score was the only variable that could significantly predict the subsidence of ROI-C cage after ACDF. Higher C-VBQ score was significantly associated with cage subsidence (P < 0.001).The AUC was 0.89, and the cutoff value for C-VBQ was 2.70.

CONCLUSION

The findings indicate a significant correlation between a higher C-VBQ score before surgery and ROI-C cage subsidence after ACDF. The preoperative assessment of C-VBQ proves valuable for clinicians, enabling them to identify patients with low bone mineral density and predict the risk of zero-profile anchored spacer interbody fusion cage subsidence following ACDF.

Comparison of Radiological and Clinical Outcomes between Expandable and Non-expandable Cages Following Cervical Corpectomy: A Systematic Review and Meta-analysis

Anterior cervical corpectomy and fusion is considered the mainstay of surgical treatment in cervical pathology. Expandable and nonexpandable cages are preferred over autogenous bone graft because of donor-related morbidity. However, the choice of the cage type remains a debatable topic as studies report conflicting results. Thus, we evaluated the outcomes of expandable and non-expandable cages following cervical corpectomy. Studies were searched in various electronic databases (MEDLINE, PubMed, EMBASE, CINAHL, Scopus, and Cochrane) between 2011 and 2021. Forest plot was made to compare the radiological and clinical outcomes between expandable and non-expandable cages following cervical corpectomy. Altogether, 26 studies (1,170 patients) were included in the metaanalysis. The mean change in segmental angle was significantly greater in the expandable cage group than in the non-expandable cage group (6.7° vs. 3.0°, p <0.001). The mean subsidence rate was lower in the expandable cage group (6% vs. 41%, p <0.001). The mean fusion rate was lower (93% vs. 98%, p =0.06) and the mean displacement rate was significantly higher in the expandable cage group (29% vs. 5%, p <0.05). The mean reoperation rate was higher in the expandable cage group (16% vs. 2%, p >0.05). The improvement in segmental angle is better with expandable cages. Higher subsidence is a major problem with non-expandable cages, but it seems to be beneficial as evidenced by the high fusion rate and minimal effect on clinical outcome in patients with this cage.

Factors Associated With the Rate of Recovery After Cervical Decompression Surgery for Degenerative Cervical Myelopathy: A Retrospective Analysis

Introduction Degenerative cervical myelopathy (DCM) is a debilitating spinal condition with a wide variety of symptoms that can differ greatly among individuals. Common symptoms include numbness, extremity weakness, loss of balance, and gait instability. Decompression surgeries are commonly indicated for the treatment of DCM with varying outcomes reported in the literature. However, there is little evidence on the rate of recovery defined as the time until improvement in symptoms such as numbness, balance, and strength after surgery for DCM. The purpose of this study was to determine the rate of neurological recovery after surgery for DCM and its subsequent association with various risk factors to guide clinicians while providing care and improve patient education. Methods This study was a retrospective case series (n=180 patients) examining patients who underwent cervical decompression surgery for DCM. All patients had a clinical presentation of DCM, were diagnosed with DCM, had radiographic degenerative changes and cervical stenosis, and received surgical management from 2010 to 2020 in a tertiary hospital system. Data recorded included age, smoking status, duration of pre-operative symptoms, preoperative and postoperative pain, and postoperative rate of recovery (days until improvement) in numbness, upper extremity strength, and balance. Results Patients (n=180) had an average age of 65.7 years (SD ±9.2 years, range 43-93 years). The mean ± standard deviation for the rate of recovery (days until improvement) in numbness, upper extremity strength, and balance was 84.5 ± 94.4 days, 50.6 ± 42.8 days, and 60.4 ± 69.9 days, respectively. There was only a marginally significant association between the rate of recovery for numbness after surgery and patient age (p=0.053). The average rate of recovery in numbness for patients older than 60 years was significantly longer than those younger than 60 years (99.3 versus 60.2 days). Preoperative smoking status was significantly associated with persistent moderate to severe pain (p=0.032) within the six-month postoperative period. No significant correlations were seen between the rate of recovery for balance or strength and patient age or preoperative duration of symptoms. Conclusion There was great variability in the rate of recovery for postoperative symptoms after surgery for DCM. A longer time for improvement in postoperative numbness was only marginally correlated with the increased patient age after surgery for DCM. There was no correlation found between strength or balance recovery times and patient age. Smoking status was associated with moderate to severe postoperative pain after surgery for DCM. Furthermore, the duration of preoperative symptoms was not associated with improvement in postoperative symptoms after surgery for DCM. More research is needed to determine factors impacting the rate of recovery after surgery for DCM.

A Novel Cervical Vertebral Bone Quality Score Independently Predicts Cage Subsidence After Anterior Cervical Diskectomy and Fusion

BACKGROUND

Surgeons can preoperatively assess bone quality using dual-energy X-ray absorptiometry or computed tomography; however, this is not feasible for all patients. Recently, a MRI-based scoring system was used to evaluate the lumbar spine's vertebral bone quality.

OBJECTIVE

To create a similar MRI-based scoring system for the cervical spine (C-VBQ), correlate C-VBQ scores with computed tomography-Hounsfield units (HU), and evaluate the utility of this scoring system to independently predict cage subsidence after single-level anterior cervical diskectomy and fusion (ACDF).

METHODS

Demographic, procedure-related, and radiographic data were collected for patients. Pearson correlation test was used to determine the correlation between C-VBQ and HU. Cage subsidence was defined as ≥3 mm loss of fusion segmental height. A multivariate logistic regression model was built to determine the correlation between potential risk factors for subsidence.

RESULTS

Of 59 patients who underwent single-level ACDF, subsidence was found in 17 (28.8%). Mean C-VBQ scores were 2.22 ± 0.36 for no subsidence levels and 2.83 ± 0.38 ( P < .001) for subsidence levels. On multivariate analysis, a higher C-VBQ score was significantly associated with subsidence (odds ratio = 1.85, 95% CI = 1.39-2.46, P < .001) and was the only significant independent predictor of subsidence after ACDF. There was a significant negative correlation between HU and C-VBQ (r 2 = -0.49, P < .001).

CONCLUSION

We found that a higher C-VBQ score was significantly associated with cage subsidence after ACDF. Furthermore, there was a significant negative correlation between C-VBQ and HU. The C-VBQ score may be a valuable tool for assessing preoperative bone quality and independently predicting cage subsidence after ACDF.

Efficacy of a newly designed helical-shaped 3D-printed titanium cage for cervical vertebral defect healing in rabbits

Three-dimensional (3D) printed titanium (Ti-6Al-4V alloy) cages are widely used for spinal fusion applications. However, the structural design and shape of the cages are a major determinant of the optimal clinical outcome. In this study, we constructed a newly designed 3D-printed helical-shaped titanium cage (HTC) with a flexible body, and compared its healing and fusion efficacy in cervical vertebral defects after corpectomy in rabbits to that of a 3D-printed traditional titanium cage (TTC). We performed radiological examinations 1 and 16 weeks after TTC and HTC implantation. We assessed bone ingrowth in TTC and HTC using micro-computed tomography (micro-CT) and histological staining of tissue sections at 16 weeks. The radiographic data showed that the HTC-implanted group had better restoration of vertebral height than the TTC group, indicating a lower risk of cage subsidence. The micro-CT and histological observations showed that HTC promoted bone regeneration and osseointegration more effectively than TTC. Histomorphometry further revealed significant new bone formation in the HTC group compared to the TTC group. These findings demonstrate that HTC has better healing and bone fusion effects than TTC in cervical vertebral defects in rabbits, indicating its potential clinical value.

Comparison of radiological and clinical outcomes of 3D-printed artificial vertebral body with Titanium mesh cage in single-level anterior cervical corpectomy and fusion: A meta-analysis

Propose

This meta-analysis aimed to determine whether 3D-printed artificial vertebral body have superior clinical and radiographic outcome than Titanium Mesh Cage(TMC) in single-level anterior cervical corpectomy and fusion.

Methods

A comprehensive search of the PubMed, Embase, Cochrane Library, Web of Science, and CNKI (China National Knowledge Infrastructure) databases was conducted to find randomized control trials (RCTs) or cohort studies that compared 3D-printed artificial vertebral body with conventional Titanium Mesh Cage (TMC) in single-level anterior cervical corpectomy and fusion (SL-ACCF). Operation time; intraoperative blood loss; subsidence of vertebral body; preoperative, and final follow-up C2-C7 Cobb angle, Japanese Orthopedic Association (JOA) scores, and Visual Analog Scale(VAS) scores were collected from eligible studies for meta-analysis.

Results

We included 6 cohort studies with 341 patients. The results of the meta-analysis showed that the 3D group has a shorter operation time than the traditional TMC group(p = 0.04) and the TMC group had more severe subsidence(≥3 mm) of vertebral body than the 3D group(p < 0.0001). And the cervical C2-C7 Cobb angle in the 3D group was larger than that in the TMC group at the final follow-up.

Conclusion

This meta-analysis demonstrates that 3D-printed artificial vertebral body is superior to traditional TMC in reducing the operation time and maintaining the postoperative vertebral height and restoring sagittal balance to the cervical spine in single-level anterior cervical corpectomy and fusion.

Biomechanical Effects of a Novel Anatomic Titanium Mesh Cage for Single-Level Anterior Cervical Corpectomy and Fusion: A Finite Element Analysis

Background: The traditional titanium mesh cage (TTMC) has become common as a classical instrument for Anterior Cervical Corpectomy and Fusion (ACCF), but a series of complications such as cage subsidence, adjacent segment degeneration (ASD), and implant-related complications by using the TTMC have often been reported in the previous literature. The aim of this study was to assess whether a novel anatomic titanium mesh cage (NTMC) could improve the biomechanical condition after surgery.

Methods: The NTMC model consists of two spacers located on both sides of the TTMC which match the anatomic structure between the endplates by measuring patient preoperative cervical computed tomography (CT) data. The ranges of motion (ROMs) of the surgical segments and the stress peaks in the C6 superior endplates, titanium mesh cage (TMC), screw–bone interface, anterior titanium plate, and adjacent intervertebral disc were compared.

Results: Compared with the TTMC, the NTMC reduced the surgical segmental ROMs by 89.4% postoperatively. The C6 superior endplate stress peaks were higher in the TTMC (4.473–23.890 MPa), followed by the NTMC (1.923–5.035 MPa). The stress peaks on the TMC were higher in the TTMC (47.896–349.525 MPa), and the stress peaks on the TMC were lower in the NTMC (17.907–92.799 MPa). TTMC induced higher stress peaks in the screw–bone interface (40.0–153.2 MPa), followed by the NTMC (14.8–67.8 MPa). About the stress peaks on the anterior titanium plate, the stress of TTMC is from 16.499 to 58.432 MPa, and that of the NTMC is from 12.456 to 34.607 MPa. Moreover, the TTMC induced higher stress peaks in the C3/4 and C6/7 intervertebral disc (0.201–6.691 MPa and 0.248–4.735 MPa, respectively), followed by the NTMC (0.227–3.690 MPa and 0.174–3.521 MPa, respectively).

Conclusion: First, the application of the NTMC can effectively decrease the risks of TMC subsidence after surgery. Second, in the NTMC, the stresses at the anterior screw-plate, bone–screw, and TMC interface are much less than in the TTMC, which decreased the risks of instrument-related complications after surgery. Finally, increases in IDP at adjacent levels are associated with the internal stresses of adjacent discs which may lead to ASD; therefore, the NTMC can effectively decrease the risks of ASD.

Clinical and radiological efficacy of corpectomy and anterior stabilization with titanium mesh cages in patients with myelopathic syndrome associated with cervical spine degenerative di

The aim of this study was to research the clinical and radiological efficacy of  corpectomy and anterior stabilization with titanium mesh cages in patients with myelopathic syndrome associated with cervical spine degenerative diseases.

Material and methods. A retrospective observational cohort study was performed. The study included medical records of patients with cervical myelopathy associated with degenerative diseases of the cervical spine who underwent corpectomy and  anterior stabilization with titanium mesh cages. Clinical and instrumental parameters were assessed.

Results. The study included 28  medical records of respondents who underwent corpectomy and anterior stabilization with titanium mesh implants. The average age of patients was 61.9 ± 11.3 years, males prevailed (60.7 %). By the 3rd month of  postoperative follow-up, the severity of myelopathy significantly decreased (p˂0.001). After 12  months, the severity of cervical myelopathic syndrome also significantly decreased (p = 0.009). The neurological status of 18 (64.2 %) respondents improved in the first 3  months after corpectomy and anterior stabilization with titanium mesh implants and 6 months after the surgery, the status improved in the remaining 8 (30.7 %) patients (p˂0.001). Preoperative values of the Cobb sagittal angle allowed us to conclude the following. In 13 (46.4 %) patients, the normolordotic axis of the cervical spine was noted, in 12  (42.8  %) – the  hypolordotic axis, and in 3 (10.8 %) respondents, the Cobb angle values corresponded to the kyphotic axis of the cervical spine.

Conclusion. The technique of corpectomy and anterior fixation with mesh titanium implants in patients with myelopathic syndrome against the background of  degenerative diseases of the cervical spine makes it possible to improve the clinical status of the latter already 3 months after the operation was performed while maintaining normal biomechanical parameters of the cervical spine and complete decompression of the neural structures and supply their vessels. 

The effects of titanium mesh cage size on the biomechanical responses of cervical spine after anterior cervical corpectomy and fusion: A finite element study

BACKGROUND

Due to the lack of sufficient studies focusing on titanium mesh cage size, there exists a puzzle among surgeons about how to determine the optimal size of cage to provide surgical segments an adequate distraction.

METHODS

The biomechanical responses of cervical spine after the implantation of cages with different heights and trimmed angles were analyzed using the finite element method. Twenty Anterior Cervical Corpectomy and Fusion models, of which the surgical segment was C5, were developed corresponding to the combinations of 4-different-heights and 5-different-trimmed angle cages. Biomechanical parameters were calculated under simulated physiological load of cervical spine. A rating scale was designed to assess the biomechanical performances of titanium mesh cages with different heights and trimmed angles comprehensively, assisting to select the most appropriate combination of cage height and trimmed angle.

FINDINGS

It was indicated that in the single-level Anterior Cervical Corpectomy and Fusion at C5 segment, a cage with a height fitting with the space between C4 and C6 as well as a trimmed angle 2° lower than the sagittal angle of C4 inferior endplate would provide adequate biomechanical environment for cervical spine to resist cage subsidence and reduce the impact to adjacent segments.

INTERPRETATION

The biomechanical responses of cervical spine are affected significantly by the height and trimmed angles of titanium mesh cage. The results of this study would provide quantitative guidance for surgeons to determine the optimal height and trimmed angle of titanium mesh cage for a specific patient in order to achieve favorable clinical outcomes.

Construction of a new cervical anatomically adaptive titanium mesh cage based on measurements of cervical geometry: A morphological and cadaveric study

Mismatch between the titanium mesh cage and cervical geometries is an important factor that induces subsidence in anterior cervical corpectomy and fusion (ACCF). The aim of the present study was to construct a new quadrate anatomically adaptive titanium mesh cage (AA-TMC) that matches well with the cervical geometries and segmental alignment in one- and two-level ACCF. Computed tomography (CT) scans of 54 individuals were used to measure the cervical endplate geometries. X-rays of 74 young individuals were used to measure the intervertebral body angle (IBA) and intervertebral body height (IBH) of the surgical segments. The AA-TMC was designed based on these measured parameters. A total of 18 cervical cadaveric specimens underwent successive one- and two-level ACCF using the AA-TMC. Postoperatively, the specimens underwent CT scanning to assess the degree of matching of the TMC-endplate interface (TEI), IBA and IBH. A TEI interval <0.5 mm was considered well matching. In the sagittal plane, 93.8% of the inferior endplates were arched, whereas 94.8% of the superior endplates were flat. In the coronal plane, 82.9% of the inferior endplates and 93.8% of the superior endplates were flat. A total of 91.7 and 94.4% of the TEIs were well matched in one- and two-level ACCF, respectively. The postoperative IBA and IBH values were consistent with the values of young individuals. The AA-TMC achieved good matching with cervical geometries and segmental alignment in one- and two-level ACCF, and is proposed for use in ACCF to increase the contact at the TEI and achieve sufficient lordosis restoration.

Determining the Difference in Clinical and Radiologic Outcomes Between Expandable and Nonexpandable Titanium Cages in Cervical Fusion Procedures: A Systematic Review and Meta-Analysis

BACKGROUND

Expandable cages have been increasingly used in cervical and lumbar reconstructions; however, there is a paucity in the literature on how they compare with traditional nonexpandable cages in the cervical spine. We present a systematic review and meta-analysis, comparing the clinical and radiologic outcomes of expandable versus nonexpandable corpectomy cage use in the cervical spine.

METHODS

A database search identified studies detailing the outcomes of expandable and nonexpandable titanium cage use in the cervical spine. These studies were screened using the PRISMA protocol. Fixed-effects and random-effects models were used with a 95% confidence interval. Two analyses were carried out for each outcome: one including all studies and the other including only studies reporting on exclusively 1-level and 2-level cases.

RESULTS

Forty-one studies were included. The mean change in segmental lordosis was significantly greater in expandable cages (all, 6.72 vs. 3.69°, P < 0.001; 1-level and 2-level, 6.81° vs. 4.31°, P < 0.001). The mean change in cervical lordosis was also significantly greater in expandable cages (all, 5.71° vs. 3.11°, P = 0.027; 1-level and 2-level, 5.71° vs. 2.07°, P = 0.002). No significant difference was found between the complication rates (all, P = 0.43; 1-level and 2-level, P = 0.94); however, the proportion of revisions was significantly greater in expandable cages (all, 0.06 vs. 0.02, P = 0.03; 1-level and 2-level, 0.08 vs. 0.01, P = 0.017).

CONCLUSIONS

The use of expandable cages may carry a modest improvement in radiologic outcomes compared with nonexpandable cages in the cervical spine; however, they may also lead to a higher rate of revisions based on our analyses.

Comparative analysis of three types of titanium mesh cages for anterior cervical single-level corpectomy and fusion in term of postoperative subsidence

A titanium mesh cage (TMC) is a common device used for interbody fusion in anterior cervical corpectomy and fusion (ACCF) surgery, with postoperative subsidence being a common complication. Among the many influencing factors, there is a paucity of research on the end-covers of the TMC. A total of 62 patients with cervical spondylotic myelopathy were treated with single-level ACCF. TMC without end-covers (group A), traditional TMC with end-covers (group B) and new TMC with end-covers (group C) were used as the fusion device. We evaluated the surgery time, intraoperative blood loss, postoperative drainage volume, postoperative fusion, falling height of the fused segment, cervical curvature and severe subsidence rate (the number of falling height of the fused segment > 3 mm/total surgical cases in the group). In addition, the Japanese Orthopaedic Association score was used for neurological status assessment and a 10-point Visual Analog Scale for postoperative neck pain. The results showed that the falling height of the fused segment in group A (1.9 ± 0.6 mm) was significantly greater than in group B (0.9 ± 0.2 mm) and group C (0.8 ± 0.3 mm). The area of the end-covers increased gradually in group A, group B and group C, while the severe subsidence rate of group A (8/20, 40%), group B (5/22, 23%) and group C (2/20, 10%) gradually decreased. The surgery time and blood loss in group B (116.4 ± 12.2 min, 183.5 ± 36.4 mL) were higher than those in group A (90.22 ± 5.60 min, 110.4 ± 20.8 mL) and group C (92.8 ± 8.47 min, 114 ± 24.0 mL). These results showed that there was a correlation between the postoperative subsidence and the end-covers of TMC. The larger the end-cover area was, the lower the severe postoperative subsidence rate was. In addition, the design of the end-covers extending inward was more conducive to the operation.

Imaging evaluation of nano-hydroxyapatite/polyamide 66 strut in cervical construction after 1-level corpectomy: a retrospective study of 520 patients

BACKGROUND

The application of nano-hydroxyapatite/polyamide 66(n-HA/PA66) struts has become reliable in anterior cervical corpectomy and fusion (ACCF) as a source of sufficient segmental stability. This was a retrospective and long-term imaging evaluation of the n-HA/PA66 strut in 1-level ACCF.

METHODS

The patients between June 2006 and December 2014, who underwent 1-level ACCF using an n-HA/PA66 strut, were reviewed. The neurological status was assessed using the Japanese Orthopedic Association (JOA) score and axial pain was evaluated using a Visual Analogue Scale (VAS) score and the radiographic parameters were determined by X-ray and 3-D CT examinations when necessary for the evaluation of bone fusion using the Brantigan scale and imaging characteristics.

RESULTS

A total of 520 patients underwent one-level ACCF, with a mean follow-up (FU) duration of 72.38 ± 24.56 months. The level of surgery was C4 in 58 cases, C5 in 173 cases, C6 in 208 cases, and C7 in 81 cases. According to the Brantigan scale, on X-ray examination, the bony fusion rate was observed to be 40%, 70%, 93%, and 98% at 3 months, 6 months, 1 year and the final FU. An interesting radiographic appearance of the bone graft growth pattern was classified into three types. 95% of the patients accounted for types a and b. No significant differences were observed in age, hospitalization duration, surgical haemorrhage volume, or fusion rate among the types except in the percentage and sex of the patients among the types. Type a had better cervical lordosis, and less subsidence than types b and c (P < 0.05). No significant difference was found in segment angle between type a and type b. Type c was more often observed with subsidence rate, segmental angle loss and cervical alignment loss than types a and b (P < 0.05). Type a also had a slightly higher fusion rate, than types b and c, but there were no significant differences. The overall mean JOA score at the final follow-up among the groups were significantly improved comparing that preoperatively and no significant differences were found among the groups, no matter pre-operation or final follow-up. The overall mean VAS score at the final follow-up among the groups were significantly improved comparing that preoperatively and no significant differences in preoperative VAS score were found among the groups. However, the VAS score at the final follow-up of type a or type b was better than type c. No patients received revision surgery.

CONCLUSIONS

The type a bone graft growth pattern could allow a lower incidence of subsidence and better maintenance of local and global alignment to be achieved and is thus proposed for surgeons.

Is it necessary to place screws in the intervening vertebrae in two-level anterior cervical discectomy with fusion and plating?

OBJECTIVE

The clinical outcomes, radiological parameters, complication rate and the cost of implants in two-level ACDF with and without screws in the intervening segment were compared.

METHODS

A retrospective study of 68 patients who underwent 2-level ACDF from January 2014 to June 2016 was performed. The patients were divided into two groups: ACDF with screws in the intervening vertebra and those without screws in the intervening vertebra. Perioperative factors, clinical outcomes, postoperative complications, radiological parameters, and cost of the implants were evaluated in both groups.

RESULTS

No statistical differences in clinical outcomes, operative blood loss, hospital stay, restoration of cervical lordosis or segment height, postoperative complications, and fusion rate were found between the ACDF (middle vertebra with screw) and ACDF (middle vertebra without screw) groups (P > 0.05). But the operative time of added screw placement and cost of implants in the ACDF (middle vertebra without screw) group were significantly less than the ACDF (middle vertebra with screw) group (P < 0.05).

CONCLUSION

Two kinds of screw placement with ACDF were found to be similar in terms of clinical outcomes. However, ACDF (middle vertebra without screw) was found to be superior to ACDF (middle vertebra with screw) in terms of the screw placement time and cost of implants.

Utilizing vertebral body autograft for anterior cervical corpectomy/fusion

Background:

There are numerous ways to reconstruct cervical vertebral bodies and achieve arthrodesis following anterior cervical corpectomy and fusion (ACF). However, device and donor site complications abound. Here, we describe a novel technique for performing ACF using the vertebral body itself as a structural autograft.

Methods:

The anterior cervical spine was accessed and discectomies were performed rostral and caudal to the corpectomy. Five millimeter troughs were drilled on the lateral borders of the vertebral body, and it was removed en bloc. The autograft was rotated 90°, and an anterior cervical plate was selected to span the length of the graft, allowing for fixation to the adjacent vertebral bodies. The plate was secured to the graft, the graft was placed in the bony defect, and the plate was secured to the adjacent levels.

Results:

This corpectomy reconstructive technique was successfully applied in a 57-year-old female with cervical myelopathy due to a C5–C6 disc herniation with caudal migration. The C6 vertebral body was used as a structural autograft. Postoperatively, the patient experienced satisfactory improvement in her myelopathy, and the construct appeared stable 8 months later.

Conclusion:

This corpectomy reconstructive technique takes advantage of the favorable osteogenic properties of autograft, while avoiding donor site morbidity as well as the cost and complications of other devices, such as cages. Further cases are required to verify the safety, efficacy, and biomechanical stability of this technique.

Comparative Analysis of 2 Different Types of Titanium Mesh Cage for Single-level Anterior Cervical Corpectomy and Fusion in Terms of Postoperative Subsidence and Sagittal Alignment

STUDY DESIGN

This was a retrospective observatory analysis study.

OBJECTIVE

The objective of this study was to compare the differences in clinical and radiologic outcomes among patients who underwent anterior cervical corpectomy and fusion (ACCF) using titanium mesh cage (TMC) with end-caps and patients who underwent ACCF using TMC without end-cap.

SUMMARY OF BACKGROUND DATA

TMC has been widely used as an effective treatment option for ACCF. However, the subsidence of TMC has been observed frequently in the early postoperative period in some cases, resulting in related clinical complications.

MATERIALS AND METHODS

Patients who underwent single-level ACCF using TMC from September 2008 to June 2014 at our institute were retrospectively reviewed. Patients treated with TMC with end-cap were classified as an end-cap group, while patients treated with TMC without end-cap classified as a control group. The round press-fit-type end-caps with 2.5-degree angulation were used at both ends of the cage for the end-cap group. Patients were followed postoperatively for a minimum of 36 months with radiologic evaluation.

RESULTS

The subsidence was lower in the end-cap group (4.3±3.6 vs. 4.8±3.0, P<0.01), with lower rates of severe subsidence (≥3 mm) than the control group (34.2% vs. 52.1%, P<0.01). Visual analogue scale (VAS) scores for neck pain and Neck Disability Index (NDI) was reported significantly less in the study group, which showed a positive correlation with lesser severe subsidence. Also, the characteristics of subsidence differed between the 2 groups. In the end-cap group, slippage type subsidence occurred, resulting in better sagittal alignment than that in the control group.

CONCLUSIONS

For patients undergoing single-level ACCF, using TMC with end-cap provided better clinical results and similar fusion rate, compared with using TMC without end-cap. The end-cap decreased the severity of postoperative subsidence and related neck pain. Also, sagittal alignment was well preserved, suggesting it may contribute to cervical lordosis.

Correlation Between Different Interbody Grafts and Pseudarthrosis After Anterior Cervical Discectomy and Fusion Compared with Control Group: Systematic Review

BACKGROUND

Cervical spine degenerative disease is one of the main causes of myelopathy. Anterior cervical discectomy and fusion (ACDF) is the most common surgical procedure used to treat cervical myelopathy. Therefore, it is important to study pseudarthrosis rates after ACDF and correlate them with the graft used.

METHODS

We performed a systematic review to evaluate the relationship between pseudarthrosis after ACDF and the interbody graft used.

RESULTS

A total of 3732 patients were evaluated in 46 studies. The mean age of the included patients was 51.5 ± 4.18 years (range, 42-59.6 years). ACDF is most often perforemd as single-level surgery and the level most impaired is C5-C6. The use of titanium cages, zero profile, recombinant human bone morphogenetic protein 2, and carbon cages was seen as a protective factor for pseudarthrosis compared with the autograft group (control group); with an odds ratio of 0.29, 0.51, 0.03, and 0.3, respectively; the results were statistically relevant. The use of polyetheretherketone, poly(methyl methacrylate), and trabecular metal was a risk factor for development of pseudarthrosis compared with the control group, with an odds ratio of 1.7, 8.7, and 6.8, respectively; the results were statistically relevant. Radiologic follow-up was an important factor for the pseudarthrosis rate; paradoxically, a short follow-up (<1 year) had lower rates of pseudarthrosis and follow-up >2 years increased the chance of finding pseudarthrosis.

CONCLUSIONS

Different types of grafts lead to a significant difference in pseudarthrosis rates. Follow-up time is also an important factor that affects the rate of pseudarthrosis after ACDF.

Posterior Surgical Techniques for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations

Objective

This study was conducted to determine and recommend the most up-to-date information on the indications, complications, and outcomes of posterior surgical treatments for cervical spondylotic myelopathy (CSM) on the basis of a literature review.

Methods

A comprehensive literature search was performed, using the MEDLINE (PubMed), the Cochrane Register of Controlled Trials, and Web of Science databases, for peer-reviewed articles published in English during the last 10 years.

Results

Posterior techniques, which include laminectomy alone, laminectomy with fusion, and laminoplasty, are often used in patients with involvement of 3 or more levels. Posterior decompression for CSM is effective for improving patients’ neurological function. Complications resulting from posterior cervical spine surgery include injury to the spinal cord and nerve roots, complications related to posterior screw fixation or instrumentation, C5 palsy, spring-back closure of lamina, and postlaminectomy kyphosis.

Conclusion

It is necessary to consider multiple factors when deciding on the appropriate operation for a particular patient. Surgeons need to tailor preoperative discussions to ensure that patients are aware of these facts. Further research is needed on the cost-to-benefit analysis of various surgical approaches, the comparative efficacy of surgical approaches using various techniques, and long-term outcomes, as current knowledge is deficient in this regard.

Surgical Reconstruction Using a Flanged Mesh Cage without Plating for Cervical Spondylotic Myelopathy and a Symptomatic Ossified Posterior Longitudinal Ligament

OBJECTIVE

We introduce innovative method of cervical column reconstruction and performed the reconstruction with a flanged titanium mesh cage (TMC) instead of a plate after anterior corpectomy for cervical spondylotic myelopathy (CSM) and an ossified posterior longitudinal ligament (OPLL).

METHODS

Fifty patients with CSM or OPLL who underwent anterior cervical reconstruction with a flanged TMC were investigated retrospectively. Odom's criteria were used to assess the clinical outcomes. The radiographic evaluation included TMC subsidence, fusion status, and interbody height. Thirty-eight patients underwent single-level and 12 patients underwent two-level corpectomy with a mean follow-up period of 16.8 months.

RESULTS

In all, 19 patients (38%) had excellent outcomes and 25 patients (50%) had good outcomes. Two patients (4%) in whom C5 palsy occurred were categorized as poor. The fusion rate at the last follow-up was 98%, and the severe subsidence rate was 34%. No differences in subsidence were observed among Odom's criteria or between the single-level and two-level corpectomy groups.

CONCLUSION

The satisfactory outcomes in this study indicate that the flanged TMC is an effective graft for cervical reconstruction.

Anterior decompression and plate fixation in treatment of cervical myelopathy: A multicentric retrospective review

OBJECTIVES

The aim of this study was to evaluate the results on anterior decompression and fusion with titanium mesh or expanding cage and plate fixation in patients with cervical myelopathy.

METHODS

We conducted a retrospective multicentric review of 114 patients, 75 males and 39 females, with cervical myelopathy who underwent surgical treatment between July 2009 to December 2011. All surgeries were performed via a ventral approach. Based on the type of surgery the patients received, they were divided into 3 groups: group 1 consisted of 49 patients who received multilevel corpectomies and fusion with strut iliac bone graft and plates; group 2 consisted of 26 patients who received multilevel corpectomies and fusion with titanium expanding cage and plating; group 3 consisted of 39 patients who received multilevel corpectomies and fusion using titanium mesh with autologous bone graft and anterior plating.

RESULTS

Decompression of the cervical spinal cord and grafting with plate fixation via a ventral approach demonstrated a high rate of improvement in neurological function with minimal complications. Fusion was documented radiologically in all cases. Eighty-three patients experienced a partial improvement and 41 had a complete recovery according to Nurick's myelopathy grading. Sixty-two patients were ranked as excellent, 48 as good, 4 as fair; unsatisfactory outcome was related to donor site complications.

CONCLUSION

Spinal decompression and fusion with titanium cages and plates appears to be a safe and effective alternative in patients with cervical spinal myelopathy.

LEVEL OF EVIDENCE

Level IV, therapeutic study.