Titanium Mesh Cage Subsidence Research Articles

The Association between High Preoperative MRI-based Vertebral Bone Quality (VBQ) Score and Titanium Mesh Cage Subsidence after Anterior Cervical Corpectomy and Fusion.

Recently, the MRI-based vertebral bone quality (VBQ) score has been shown to correlate with Hounsfeld units (HU) value, dual-energy X-ray absorptiometry (DEXA) T-score and predict osteoporotic fractures. Preoperative cervical HU value is an independent correlative factor for early titanium mesh cage (TMC) subsidence after anterior cervical corpectomy and fusion (ACCF). However, to date the direct association between cervical VBQ score and TMC subsidence has not been studied. This study aims to investigate the predictive effect of cervical VBQ score derived from sagittal non-contrast-enhanced T1-weighted MRI on the early TMC subsidence after ACCF. Patients who underwent one-level ACCF from January 2016 to January 2020 were included. We retrospectively collected baseline data on age, sex, body mass index (BMI), disease type, level of surgery and radiology parameters. The cervical VBQ score was measured using preoperative non-contrast-enhanced T1-weighted MRI. Univariate and multivariate logistic regression analysis were performed to screen the independent risk factors of TMC subsidence. The receiver operating characteristic (ROC) curve and area under curve (AUC) were performed to assess the predictive ability of TMC subsidence based on the cervical VBQ score. Spearman correlation analysis was used to determine the correlations between the cervical VBQ score and TMC subsidence. A total of 134 patients who underwent one-level ACCF were included in this study, and 46 (34.33%) patients had TMC subsidence. Univariable analyses demonstrated that the age, TMC placement depth and VBQ score were associated with subsidence. The cervical VBQ score in the subsidence group was significantly higher than that in the no subsidence group (3.75 ± 0.45 vs. 3.20 ± 0.42, p < 0.001). The multivariate logistic regression analysis proved that the higher VBQ score (odds ratio[OR] = 13.563, 95% confidence interval [CI] 4.968 - 37.031, p < 0.001) was the only variable that significantly predicted subsidence. Using a VBQ score cutoff value of 3.445, the cervical VBQ score yielded a sensitivity of 69.6% and a specificity of 85.2% with an AUC of 0.810 to differentiate patients with subsidence and with no subsidence. Preoperative higher cervical VBQ score is an independent risk factor for TMC subsidence after ACCF. The cervical VBQ score may be a valuable tool for assisting in distinguishing the presence of TMC subsidence.

Predictive value of vertebral Hounsfiled Unit for titanium mesh cage subsidence following ACCF surgery

ObjectiveTo investigate the predictive value of cervical Hounsfiled Unit (HU) values for postoperative titanium mesh cage (TMC) subsidence. MethodsClinical data of patients who underwent ACCF surgery for degenerative cervical myelopathy between January 2016 and August 2018 were analyzed. Among the 126 patients included, 74 were male and 52 were female, with a mean age of 61.0 ± 9.9 years. The mean follow-up was 37.1 ± 11.2 months. Preoperative vertebral HU values were measured and the degree of TMC subsidence during follow-up was assessed. Patients were divided into two groups according to the presence or absence of subsidence: the subsidence group and the control group. Vertebral HU values were compared between the two groups, and correlation analysis was performed between HU values and TMC subsidence values. In addition, the predictive value and threshold of HU were analyzed by using ROC. ResultsThere were 22 patients (14 males and 8 females) who developed TMC subsidence (subsidence group), while 104 patients (60 males and 44 females) did not develop TMC subsidence (control group) during follow-up. Comparative analysis of demographic characteristics between the two groups showed no significant differences in gender, age, BMI, diagnosis, surgical levels, and follow-up duration (all P values > 0.05). There was a significant difference in mean HU between the subsidence group (287.6 ± 49.6) and the control group (342.4 ± 61.4) (t = −3.92, P < 0.01). In the subsidence group, there was a significant correlation between subsidence values and HU values (r = −0.52, P = 0.01), whereas no such correlation was observed in the control group (r = - 0.07, P = 0.51). ROC analysis indicated that vertebral HU values could potentially be used to predict subsidence after ACCF, with an area under the ROC curve of 0.77 (95% CI 0.66–0.87; P < 0.01). The optimal HU threshold was found to be 298, with a sensitivity of 76.9% and specificity of 68.2%. ConclusionPreoperative vertebral HU values were associated with postoperative TMC subsidence. Vertebral HU may be a valuable predictor of postoperative subsidence.

Physiologic Osseous Remodeling of the Anterior Wall of the Spinal Canal after Anterior Cervical Corpectomy and Fusion: A Retrospective Observational Study.

Anterior cervical corpectomy and fusion (ACCF) has been widely used in the treatment of cervical spondylotic myelopathy (CSM), ossification of posterior longitudinal ligament (OPLL), cervical trauma, and other cervical diseases, but few studies have reported the osseous and physiologic remodeling of the anterior wall of the spinal canal following ACCF. In this study, we analyze that remodeling process and its influence on titanium mesh cage (TMC) subsidence. We performed a clinical and radiologic analysis of consecutive patients treated with ACCF. Growth rates (GRs) reflecting the extent of remodeling of the remnants of the resected vertebral bodies were measured. We compared the computed tomography (CT) scans taken immediately and at least 1 year after surgery, and a literature review was conducted. In all, 48 patients underwent ACCF at a mean age of 61.5 ± 12.0 years. The median follow-up was 36 months, and 159 CT images were analyzed. The GR values of the remnants of the vertebral bodies on CT images immediately and 1 year after surgery were 0.505 ± 0.077 and 0.650 ± 0.022 (p < 0.001), respectively, and the GR value at ≥4 years was 1. Axial CT scans showed that remodeling starts from the lateral remnants of the resected vertebral bodies, finally reaching the center. When fusion of the vertebral bodies and the titanium cage was complete during the first year after ACCF, osteogenesis and remodeling were initiated in the osseous anterior wall of the spinal canal. The remodeling of the osseous anterior wall of the spinal canal was completed at the fourth year after surgery, without recompressing the spinal cord, as seen on both axial and lateral CT scans. According to the literature review, there was no TMC subsidence at more than 4 years after surgery. The anterior wall of the spinal canal undergoes osseous remodeling after ACCF. The process is complete in the fourth year after surgery and prevents TMC subsidence.

Posterior unilateral approach with 270° spinal canal decompression and three-column reconstruction using double titanium mesh cage for thoracic and lumbar burst fractures.

To evaluate the clinical effects of the posterior unilateral approach with 270° spinal canal decompression and three-column reconstruction using double titanium mesh cage (TMC) for thoracic and lumbar burst fractures. From May 2013 to May 2018, 27 patients with single-level thoracic and lumbar burst fractures were enrolled. Every patient was followed for at least 18 months. Demographic data, neurologic status, back pain, canal compromise, anterior body compression, operative time, estimated blood loss and surgical-related complications were evaluated. Radiographs were reviewed to assess deformity correction, anterior body height correction, bony fusion and TMC subsidence. The average preoperative percentages of canal compromise and anterior body height compression were 58.4% and 50.5%, respectively. All surgeries were successfully completed in one phase, the operative time was 151.5 ± 25.5 min (range: 115-220 min), the estimated blood loss was 590.7 ± 169.9 ml (range: 400-1,000 ml). Neurological function recovery was significantly improved except for 3 grade A patients. The preoperative visual analog scale (VAS) scores for back pain were significantly decreased compared with the values at the last follow-up (P = 0.000). The correct deformity angle was 12.4 ± 4.7° (range: 3.9-23.3°), and the anterior body height recovery was 96.7%. The TMC subsidence at the last follow-up was 1.3 ± 0.7 mm (range: 0.3-3.1 mm). Bony fusion was achieved in all patients. The posterior unilateral approach with 270° spinal canal decompression and three-column reconstruction using double TMC is a clinically feasible, safe and alternative treatment for thoracic and lumbar burst fractures.

The predictive value of Hounsfield units for titanium mesh cage subsidence after anterior cervical corpectomy and fusion.

To investigate whether bone mineral density (BMD) measured in Hounsfield units (HUs) correlates with titanium mesh cage (TMC) subsidence after anterior cervical corpectomy and fusion (ACCF). A total of 64 patients who underwent one or two levels of ACCF with TMC with a mean follow-up of 19.34 ± 7.86 months were analysed. HU values were measured three times in 3 different planes in the upper and lower vertebrae according to published methods. Subsidence was defined as segmental height loss of more than 3 mm. Pearson correlation analysis was performed. Receiver operating characteristic (ROC) curve analysis was used to obtain optimal thresholds. A multivariate logistic regression analysis was also conducted. Twenty-two patients (34.38%) had evidence of TMC subsidence on follow-up x-ray. The mean HU values in the subsidence group (317.34 ± 32.32, n = 22) were significantly lower than those in the nonsubsidence group (363.07 ± 25.23 n = 42, p < 0.001, t test). At last follow-up, mean disc height loss was 4.80 ± 1.16 mm in the subsidence group and 1.85 ± 1.14 mm in the nonsubsidence group (p < 0.001). There was a negative correlation between HU values and disc height loss (Pearson's coefficient -0.494, p < 0.001). HU values decreased gradually from the C3 vertebra to the C7 vertebra, and the HU values of the C5, C6, and C7 vertebrae in the nonsubsidence group were significantly higher than those in the subsidence group (p < 0.05). Furthermore, there were significant differences between the groups in the segmental angle at the last follow-up and the mean changes in segmental angle (p < 0.05). The area under the ROC curve was 0.859, and the most appropriate threshold of the HU value was 330.5 (sensitivity 100%, specificity 72.7%). The multivariate logistic regression analysis showed that older age (p = 0.033, OR = 0.879), lower LIV HU value (p < 0.001, OR = 1.053) and a greater segmental angle change (p = 0.002, OR 6.442) were significantly associated with a higher incidence of TMC subsidence after ACCF. There are strong correlations between a lower HU value and TMC subsidence after ACCF. More accurate assessment of bone quality may be obtained if HU measurement can be used as a routine preoperative screening method together with DXA. For patients with HU values <330.5, a more comprehensive and cautious preoperative plan should be implemented to reduce TMC subsidence.

Factors affecting titanium mesh cage subsidence in single-level anterior cervical corpectomy and fusion for ossification of the posterior longitudinal ligament

PurposeTo analyze risk factors of titanium mesh cage (TMC) subsidence in single-level anterior cervical corpectomy and fusion (ACCF) for cervical ossification of the posterior longitudinal ligament (OPLL).MethodsTMC subsidence is defined as the reduction of the adjacent vertebral bodies by ≥ 2 mm. Patients with cervical OPLL who were treated with single-level ACCF between January 2019 and May 2021 were retrospectively analyzed in two groups: patients with TMC subsidence as Group S and patients with no TMC subsidence as Group N during the one-year follow-up period. The degree of distraction of surgical segment and correction of the cervical curvature was measured to analyze their relationship with TMC subsidence.ResultsA total of 128 patients were included in Group S, and 138 patients were included in Group N. There was no significant difference in patient demographics and complications between the two groups. The degree of distraction in Group S was significantly higher than that in Group N (11.4% ± 7.6% vs. 4.7% ± 9.7%, P < 0.01). The change of C2 to C7 Cobb angle (α) in Group S was significantly greater than that in Group N (5.7 ± 2.7 vs. 1.4 ± 4.7, P < 0.01), and the change of interspinous process distance (SPD) in Group S was also significantly greater than that in Group N (7.0 ± 4.2 vs. 4.1 ± 2.7, P < 0.01). The JOA score and JOA recovery rate were not statistically different between the two groups.ConclusionsIntraoperative selection of overlength TMC in single-level ACCF for OPLL, over-distraction and excessive correction of the cervical curvature may cause TMC subsidence after surgery. No significant impact of TMC subsidence on the surgical outcome was observed during the 1-year follow-up period.

Low cervical vertebral CT value increased early subsidence of titanium mesh cage after anterior cervical corpectomy and fusion

Study designThis study was a retrospective review.ObjectiveTo study the predictive effect of Hounsfield units (HU) value in the cervical vertebral body derived from computed tomography (CT) on the early titanium mesh cage (TMC) subsidence after anterior cervical corpectomy and fusion (ACCF).MethodsThis retrospective study was conducted on patients who underwent ACCF at one institution between January 2014 and December 2018. We collected date included age, gender, body mass index (BMI), disease type, surgical segment, whether merge ACDF, HU value of the vertebral body and endplate, vertebral body height loss, cervical lordosis angle, and cervical sagittal alignment. VAS, JOA, and NDI were used to assess clinical efficacy. Univariate analysis was performed to screen the influencing factors of TMC subsidence, and then logistic regression was used to find out the independent risk factors. The ROC curve and area under curve (AUC) were used to analyze the HU value to predict the TMC subsidence.ResultsA total of 85 patients who accepted ACCF were included in this study, and early titanium mesh cage subsidence was demonstrated in 29 patients. The subsidence rate was 34.1%. The JOA, VAS, and NDI scores significantly improved in both groups after the operation. Between the subsidence and non-subsidence groups, there were significant differences in age, intervertebral distraction height, and HU value in both upper and lower vertebral body and endplate. The logistic regression analysis proved that the HU value of the lower vertebral body was an independent risk of TMC subsidence, the AUC was 0.866, and the most appropriate threshold of the HU value was 275 (sensitivity: 87.5%, specificity: 79.3%).ConclusionPreoperative cervical CT value is an independent correlative factor for early TMC subsidence after ACCF, and patients with a low CT value of the inferior vertebral body of the operative segment have a higher risk of TMC subsidence in the early postoperative period.Trial registration: This study is undergoing retrospective registration.

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.

A novel anatomic titanium mesh cage for reducing the subsidence rate after anterior cervical corpectomy: a finite element study

Fusion with a titanium mesh cage (TMC) has become popular as a conventional method after cervical anterior corpectomy, but postoperative TMC subsidence has often been reported in the literature. We designed a novel anatomic cervical TMC to reduce the postoperative subsidence rate. According to the test process specified in the American Society of Testing Materials (ASTM) F2267 standard, three-dimensional finite element analysis was used to compare the anti-subsidence characteristics of a traditional TMC (TTMC) and novel TMC (NTMC). Through analysis, the relative propensity values of a device to subside (Kp) of the TTMC and NTMC were 665.5 N/mm and 1007.2 N/mm, respectively. A higher Kp measurement is generally expected to indicate that the device is more resistant to subsidence into a vertebral body. The results showed that the novel anatomic titanium mesh cage (NTMC) significantly improved the anti-subsidence performance after anterior cervical corpectomy and fusion (ACCF), which was approximately 51.3% higher than that of the traditional titanium mesh cage.

Risk factors for subsidence of titanium mesh cage following single-level anterior cervical corpectomy and fusion

BackgroundTo clarify the risk factors for subsidence of titanium mesh cage (TMC) following single-level anterior cervical corpectomy and fusion (ACCF) to reduce subsidence.MethodsThe present retrospective cohort study included 73 consecutive patients who underwent single-level ACCF. Patients were divided into subsidence (n = 31) and non-subsidence groups (n = 42). Medical records and radiological parameters such as age, sex, operation level, segmental angle (SA), cervical sagittal angle (CSA), height of anterior (HAE) and posterior endplate (HPE), ratio of anterior (RAE) and posterior endplate (RPE), the alignment of TMC, the global cervical Hounsfield Units (HU) were analyzed. Clinical results were evaluated using the Japanese Orthopedic Association (JOA) scoring system and the Visual Analog Scale (VAS).ResultsSubsidence occurred in 31 of 73 (42.5%) patients. Comparison between the groups showed significant differences in the value of RAE, the alignment of TMC and the global cervical HU value (p < 0.001, p = 0.002, p < 0.001). In multivariate logistic regression analysis, RAE > 1.18 (OR = 6.116, 95%CI = 1.613–23.192, p = 0.008), alignment of TMC > 3° (OR = 5.355, 95%CI = 1.474–19.454, p = 0.011) and the global cervical HU value< 333 (OR = 11.238, 95%CI = 2.844–44.413, p = 0.001) were independently associated with subsidence. Linear regression analysis revealed that RAE is significantly positive related to the extent of subsidence (r = − 0.502, p = 0.006).ConclusionOur findings suggest that the value of RAE more than 1.18, alignment of TMC and poor bone mineral density are the risk factors for subsidence. TMC subsidence does not negatively affect the clinical outcomes after operation. Avoiding over expansion of intervertebral height, optimizing placing of TMC and initiation of anti-osteoporosis treatments 6 months prior to surgery might help surgeons to reduce subsidence after ACCF.

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

ObjectiveWe 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). MethodsFifty 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. ResultsIn 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. ConclusionThe satisfactory outcomes in this study indicate that the flanged TMC is an effective graft for cervical reconstruction.

Total En Bloc Spondylectomy for Solitary Metastatic Tumors of the Fourth Lumbar Spine in a Posterior-Only Approach

Total en bloc spondylectomy (TES) significantly decreases the rate of local recurrence and provides long-term survival in patients with malignant tumor of the spine. This procedure can be performed through a posterior-only approach. However, TES for lower lumbar spine through a posterior-only approach is technically challenging. We retrospectively reviewed 9 patients with solitary metastatic tumors of the fourth lumbar spine who underwent TES in a posterior-only approach from June 2012 to December 2015. This series included 5 female and 4 male patients, with a mean age of 54.1 years. Endpoints included length of surgery, estimated blood loss, visual analogue scale for pain, instrumentation failure, perioperative complications, local control rate, and overall survival. All patients underwent TES and circumferential reconstruction of the involved level. Average operative time and estimated blood loss were 282 minutes and 2421 mL, respectively. The mean follow-up time was 41.2 months. We encountered nerve roots stretches in all patients during the surgeries. Three patients experienced acute lower-extremity neurologic dysfunction, but the symptoms were significantly alleviated in 4 weeks postoperatively and fully resolved within 6 months. Five patients showed no evidence of disease at the latest follow-up. Three patients died of metastasis and systemic failure. One patient developed new metastases and was alive with disease. Titanium mesh cage subsidence was observed in 3 patients, but no implant failures or related clinical symptoms were found. TES for the fourth lumbar spine in a posterior-only approach is feasible. Although the surgery is challenging, long-term oncologic and neurologic outcomes are satisfying.

Total en bloc spondylectomy for spinal tumors of the fourth lumbar spine via a posterior approach: our clinical experience

Objective To study the feasibility and safety of total en bloc spondylectomy (TES) for bone tumors of the fourth lumbar spine and evaluate the clinical outcomes. Methods From March 2011 to December 2013, 21 patients undergone total en bloc spondylectomy in posterior-only approach were retrospectively reviewed. The patients included 9 males and 12 females, with a mean age of 47.1±15.6 years old (range, 15-71 years old). This series included 12 cases of primary bone tumors and 9 cases of solitary metastases. Preoperative evaluation according to clinical, imaging and pathologic features was performed meticulously to select patients. The length of surgery, estimated blood loss, surgical margins, instrumentation failure, perioperative complications, Frankel scale, visual analogue scale (VAS) for pain, local control rate and overall survival were reviewed and analyzed. Results Total en bloc spondylectomy was performed successfully in all patients. Average operative time and estimated blood loss were 297.6±44.6 min (range, 225-420 min) and 2 247.1±904.5 ml (range, 900-4100 ml), respectively. The mean follow-up time was 50.4±17.1 mons (range, 24-79 mons). All patients encountered nerve roots stretch and 5 patients (23.8%) showed lower extremeties neurological dysfunction. All of them improved in 2-4 weeks postoperatively and recovered completely at 6-month follow-up. Cerebrospinal fluid leak was found in 4 patients (19.0%). The VAS score was 1.5±1.4 at post-operation, which was significantly lower than the 6.2±1.6 in average at operation (P=0.008). Three patients with metastatic tumors died during the follow-up. Titanium mesh cage subsidence was observed in 7 patients (33.3%). No implant failure was occurred during the follow-up. Conclusion Total en bloc spondylectomy for tumors of the fourth lumbar spine in a posterior-only approach is feasible. However, there are many intraoperative neurological complications and the indications for TES are extremely limited. Key words: Lumbar spine; Spinal neoplasm; Surgical procedure; Treatment outcome

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

Anterior cervical corpectomy and fusion (ACCF) is an effective surgical technique for cervical spondylotic myelopathy (CSM). However, no data exist regarding long-term outcomes after ACCF with the dynamic cervical plate for CSM. This study aimed to provide minimum 5-year clinical and radiographic outcomes of anterior corpectomy and reconstruction using dynamic cervical plate and titanium mesh cage (TMC) for CSM.Thirty-five patients who underwent single- or 2-level ACCF with dynamic cervical plate and TMC for the treatment of CSM were retrospectively investigated. The Japanese Orthopedic Association (JOA) score was used to assess the clinical outcome. Radiographic evaluations included TMC subsidence, fusion status, cervical lordosis, segmental angle, and segmental height.Twenty-eight patients underwent single-level and 7 patients underwent 2-level corpectomy with a mean follow-up period of 69.5 months. The average preoperative JOA score was 11.3 ± 3.0 and improved significantly to 14.2 ± 2.0 at the last follow-up (P < .001). Both cervical lordosis (P = .013) and segmental angle (P = .001) were significantly increased toward lordosis at the last follow-up. The TMC subsidence rate was 31.4% (n = 11) at the last follow-up. There was no significant difference in JOA recovery rate between subsidence and no subsidence group (P = .43). All patients obtained solid fusion at 1-year follow-up.Anterior corpectomy and reconstruction with dynamic cervical plate and TMC might be an effective method for the treatment of CSM at a minimum 5-year follow-up. It can maintain or restore cervical sagittal alignment. Subsidence of the TMC did not influence the clinical outcome.

Effects of Titanium Mesh Cage End Structures on the Compressive Load at the Endplate Interface: A Cadaveric Biomechanical Study.

BackgroundThis study aimed to evaluate whether obliquely angled and ring-shaped titanium mesh cage (TMC) end structures can improve the compressive load on the endplate interface in anterior cervical corpectomy and fusion (ACCF).Material/MethodsA total of 23 volunteers underwent cervical lateral x-ray. The oblique angle of the superior endplate was measured, which was used to construct the gradient of the TMC end. Forty-two fresh cadaveric vertebral bodies were harvested and randomly distributed among four TMC groups with different ends. The baseline indicators of bone mineral density and anteroposterior and transverse dimensions were recorded. The superior endplate was placed at an angle of 12° when performing uniaxial compression testing. The maximum loads of the four TMCs were assessed.ResultsThere were no significant differences among the groups regarding the baseline indicators. The conventional TMC had the lowest maximum load (1362.3±221.78 N, p<0.05), whereas the TMC with an obliquely end ring had the highest maximum load (2095.82±285.64 N, p<0.05). The maximum loads of the TMCs with oblique footprints and flat end ring were much higher than that of the conventional TMC (p<0.05) but significantly lower than that of the TMC with the obliquely end ring (p<0.05), with average values of 1806.91±246.98 N and 1725.3±213.33 N, respectively.ConclusionsBoth the ring shape and oblique angle of the TMC end contributed to an increase in compressive force and are advocated for use in TMC structure optimization to decrease the incidence of TMC subsidence in ACCF.

Anterior decompression and hybrid reconstruction with titanium mesh cage plus plate and self-locking stand-alone cage for the treatment of three-level cervical spondylotic myelopathy

It has been reported that anterior cervical decompression has good clinical outcomes for the treatment of adjacent three-level cervical spondylotic myelopathy (CSM). However, the application of a long plate in the anterior cervical spine poses substantial risks of soft tissue damage. In this retrospective study, we aimed to analyze the clinical and radiological results of the hybrid construction with titanium mesh cage (TMC) plus plate and self-locking stand-alone cage for treatment of adjacent three-level CSM. A total of 28 consecutive patients with adjacent three-level CSM were treated by anterior decompression and hybrid reconstruction with TMC plus plate and self-locking stand-alone cage. Clinical outcomes, complications, fusion rate and time, cage subsidence and spinal curvature were assessed. The mean follow-up period was 22.8months. The average operative time was 103±18.5min, and the average blood loss was 115±13.3mL. The JOA score and degree of spinal curvature were significantly increased at the final follow-up compared with preoperatively (P<0.05). Twenty-seven cases finally achieved a solid fusion, and the average time to achieve a solid fusion was 6.2months. Postoperative complications included one case of cerebrospinal fluid leakage (3.57%), one case of temporary sore throat (3.57%) and two cases of TMC subsidence (7.1%). No dysphagia and hoarseness were observed. Anterior decompression and hybrid reconstruction with TMC plus plate and self-locking stand-alone cage could be used safely and effectively for the treatment of adjacent three-level CSM. It could effectively restore cervical lordosis, reduce the complications related to long plate fixation, and lead to satisfactory outcomes.

Debridement, internal fixation, and reconstruction using titanium mesh for the surgical treatment of thoracic and lumbar spinal tuberculosis via a posterior-only approach: a 4-year follow-up of 28 patients.

BackgroundThe standard recommended method for surgical treatment of spinal tuberculosis is an anterior approach for debridement and fusion combined with posterior instrumentation. However, the method has its disadvantages. The aim of this study was to analyze the effectiveness and safety of treating thoracic and lumbar spinal tuberculosis with debridement, internal fixation reconstruction, and using specially formed titanium mesh cages via a posterior-only approach.MethodsThe authors retrospectively reviewed the cases of 28 patients with spinal tuberculosis treated by debridement, internal fixation, and reconstruction with a specially formed titanium mesh cage via a posterior-only approach. The levels involved were less than two contiguous vertebrae: 13 thoracic vertebrae, 5 thoracolumbar vertebrae, and 10 lumbar vertebrae. All patients suffered from back pain, and nine patients had neurologic deficits (two were class C and seven were in class D according to the American Spinal Injury Association classification). All patients were followed up every 3 months after surgery, with a minimum 48-month follow-up. The clinical efficacy was evaluated based on the visual analog scale (VAS), the Oswestry Disability Index (ODI), neurological status, kyphosis angle, and erythrocyte sedimentation rate (ESR).ResultsAll patients obtained solid bony fusions without failure of fixation. The infections were resolved in all patients, as noted by normalization of their ESR. The average surgery time was 2 h and 15 min, with an average blood loss of 435 ml. The VAS scores dropped from a preoperative level of 6.31 ± 1.25 to the final follow-up level of 0.57 ± 0.14. The ODI scores dropped from 39.14 ± 12.38 preoperatively to 7.29 ± 3.09 at 1 year postoperatively and 6.77 ± 2.53 at final follow-up. The kyphosis Cobb’s angle was corrected from 22.31° ± 4.26° preoperatively to 5.86° ± 0.57° at final follow-up. No subsidence of titanium mesh cage or posterior instrumentation failure was observed postoperatively. The neurological outcome increased by 1–2 grades in the patients with neurological deficits.ConclusionsDebridement, internal fixation, and reconstruction using specially formed titanium mesh cages via a posterior-only approach is effective and safe for treating adults with thoracic and lumbar spinal tuberculosis involving less than two contiguous levels.

Evaluation of a new type of titanium mesh cage versus the traditional titanium mesh cage for single-level, anterior cervical corpectomy and fusion

A retrospective review of prospectively collected data in an academic institution. To evaluate the safety and efficacy of a new type of titanium mesh cage (TMC) in single-level, anterior cervical corpectomy and fusion (ACCF). Fifty-eight patients consecutive with cervical spondylotic myelopathy (CSM) from cervical degenerative spondylosis and isolated ossification of the posterior longitudinal ligament were treated with a single-level ACCF using either a new type of TMC (28 patients, group A) or the traditional TMC (30 patients, group B). We evaluated the patients for TMC subsidence, cervical lordosis (C2-C7 Cobb and Cobb of fused segments) and fusion status for a minimum of 30 months postoperatively based on spine radiographs. In addition, neurologic outcomes were evaluated using the Japanese Orthopedic Association (JOA) scores. Neck pain was evaluated using a 10-point visual analog scale (VAS). The loss of height of the fused segments was less for group A than for group B (0.8 ± 0.3 vs. 2.8 ± 0.4 mm) (p < 0.01); also, there was a lower rate of severe subsidence (≥3 mm) in group A (4 %, 1/28) than in group B (17 %, 5/30) (p < 0.01). There were no differences in the C2-C7 Cobb and Cobb of fused segments between the groups preoperatively or at final follow-up (p > 0.05), but the Cobb of fused segments immediately postoperative were significantly less for group B than for group A (p < 0.01). All patients, however, had successful fusion (100 %, each). Both groups had marked improvement in the JOA score after operation (p < 0.01), with no significant differences in the JOA recovery ratio (p > 0.05). The postoperative VAS neck pain scores for group A were significantly less than that for group B (p < 0.05); severe subsidence was correlated with neck pain. The new type of TMC provides comparable clinical results and fusion rates with the traditional TMC for patients undergoing single-level corpectomy. The new design TMC decreases postoperative subsidence (compared to the traditional TMC); the unique design of the new type of TMC matches the vertebral endplate morphology which appears to decrease the severity of subsidence-related neck pain in follow-up.

Anatomy-related risk factors in Harm's mesh subsidence in cervical reconstruction after one-level corpectomy

Objective To clarify anatomy-related factors in the cervical spine with subsidence of titanium mesh cage (TMC) after one-level cervical corpectomy and fusion. The effect of the cervical posture, segmental curvature and endplate gradient on this postoperative phenomenon was evaluated. Methods Between August 2003 and March 2006, a total of the 236 patients underwent one-level corpectomy and TMC fusion. Their radiological examinations were reviewed and clinical outcomes evaluated. Results In the patients who were followed up for 12 months, TMC subsidence occurred in 54 (28.6%) cases. C6 corpectomy had a significant higher risk (26/60, 43.3%) for TMC subsidence, which was correlated with the variation of the gradient of the vertebral endplates against cervical levels. Although the clinical outcome was comparable with those in the literature, the patients may have subsidence-related problems such as neck-shoulder pain, neurological deterioration and instrumental failure. Conclusion To decrease the incidence of subsidence, TMC design should be optimized to be in line with anatomic characteristics of the cervical spine.

Subsidence of Titanium Mesh Cage

A cohort study. To clarify the risk factors for the subsidence of the titanium mesh cage (TMC) after anterior cervical corpectomy and fusion, and to discuss their clinical correlations. Fusion with TMC after anterior cervical corpectomy has become popular as an established treatment for cervical degenerative diseases, but postoperative TMC subsidence has often been reported in the literature. A total of 300 patients with anterior cervical corpectomy and TMC fusion were included in the study, including 1-level corpectomy in 236 patients and 2-level corpectomy in 64. TMC subsidence, radiologic findings, and clinical results were evaluated in the 12-month follow-up period. TMC subsidence occurred in 239 (79.7%) cases, including mild subsidence (1 to 3 mm) in 182 (60.7%) and severe subsidence (>3 mm) in 57 (19.0%). Two-level corpectomy was more susceptible to severe subsidence, when compared with 1-level corpectomy (P<0.001). Japanese Orthopedic Association recovery rate for severe subsidence was significantly lower than that for no subsidence (P=0.010). Severe subsidence was correlated with subsidence-related complications, including neck pain, neurologic deterioration, and instrument failure. TMC subsidence was a common phenomenon after anterior cervical corpectomy and fusion with TMC. Level of corpectomy was a unique risk factor for severe subsidence in this study, which might have led to bad clinical results and subsidence-related complications.