Cervical sagittal alignment after different anterior discectomy procedures for single-level cervical degenerative disc disease: randomized controlled trial

Application and Advantages of the Trans-Unco-Discal (TUD) Approach for Cervical Spondylotic Myelopathy and Radiculopathy: Classification and Modification of Surgical Technique Based on the Location of Spinal Cord and/or Nerve Root Compression

Purpose: We assess the application and advantages of modifying the trans-unco-discal (TUD) approach which we underwent for cervical myelo-radiculopathy. We present the surgical techniques of the modified TUD approach. Materials and Methods: The material was 180 cases where anterior cervical decompression (ACD) was performed by the modified TUD approach. We classified the material into four groups based on the location of the nerve root and/or spinal cord compression: I, compression of the root at intervertebral foramen (IVF); II, compression of the posterior margin of the vertebral body; III, compression of the IVF and posterior margin of the vertebral body; IV, compression of the bilateral IVF and posterior margin of the vertebral body. We applied the modified TUD approach to these four types. We present the surgical procedures and techniques for the modified TUD approach. The Japanese orthopedic association (JOA) score and neuroradiological alignment were examined. Results: The improvement rate of the JOA score was 78.4% at 6 months post-surgery and 77.5% in the most recent examinations. By the modified TUD approach, compressive lesions of the spinal cord and/or nerve roots were removed, and good alignment was acquired and sustained. Conclusions: ACD by the modified TUD approach safely achieved appropriate decompression for the spinal cord and/or nerve roots, and the patients had a high improvement rate and good alignment. Complications were less common than with other surgical procedures. If the TUD approach and endoscopic approaches can be combined, their application to new area is anticipated.

The Variability and Contributions to Cost of Anterior Cervical Discectomy and Fusion Constructs

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

To characterize the variability in cost for anterior cervical discectomy and fusion (ACDF) constructs and to identify key predictors of procedural cost.

SUMMARY OF BACKGROUND DATA

ACDF is commonly performed for surgical treatment of cervical radiculopathy and myelopathy. Numerous biomechanical constructs and graft/biological options are available, with most demonstrating relatively equivalent clinical results. Despite the substantial focus on value in spine care, the differences and contributions to procedural cost in ACDF have not been well defined.

MATERIALS AND METHODS

We evaluated the records of patients who underwent a single level ACDF from 2016 to 2020 at 4 hospitals in a major metropolitan area. We abstracted demographics, insurance status, operative time, diagnosis, surgeon, institution, and components of procedural costs. Costs based on construct were compared using multivariable adjusted analyses using negative binomial regression. The primary outcome measures were cost differences between ACDF techniques.

RESULTS

Two hundred sixty-four patients were included, with procedures by 13 surgeons across 4 institutions. The total procedural cost for ACDF had a mean of US$2317 with wide variation (range, US$967-US$7370). Multivariable analysis revealed body mass index and use of polyether ether ketone to be correlated with increased cost while carbon fiber and autograft correlated with decreased cost. When comparing standalone device constructs to cases with anterior instrumentation (plate/screws), the total cost was significantly higher in the plate/screw group (US$2686±US$921 vs. US$1466±US$878, P<0.001).

CONCLUSIONS

We encountered wide variation in procedural costs associated with ACDF, including as much as an 8-fold difference in the cost of constructs. The most important drivers included instrumentation type and implant materials. Here, we identify potential targets of opportunity for health care organizations that are looking to reduce variance in procedural expenditures to improve health care savings associated with the performance of ACDF.

Anterior cervical discectomy and fusion without plate (ACDFWP) versus anterior cervical disc arthroplasty (ACDA) for cervical spondylosis: A meta-analysis and literature review

This meta-analysis compared the clinical outcomes between two alternative surgeries for patients with cervical spondylosis, namely anterior cervical discectomy and fusion (ACDF) without plate (ACDFWP) vs. anterior cervical disc arthroplasty (ACDA). We searched databases, including PubMed, EMBASE, Cochrane Library, Google Scholar, and Web of Science (firstly available-2019). A standard meta-analysis was performed with the included studies. A Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool was used for the evaluation of the study quality of nonrandomized-controlled trials (nRCTs), while a Risk of Bias (RoB) battery was used for randomized controlled trials (RCTs). Eight studies involving 640 patients were included. No significant difference was found in the indices of Neck Disability Index (NDI) score, Visual Analog Score (VAS), Japanese Orthopaedic Association (JOA) score, operative time, blood loss, Swallowing Quality of Life Score (SWAL-QL), and complications. Cervical alignment was significantly better in the ACDFWP than in ACDA (mean difference (MD) = -0.67, 95% confidence interval (CI) [-1.11, -0.23], P = 0.003, I ² = 20%). Although the alternative ACDFWP was slightly superior in terms of the index of cervical alignment, the limited research on this subject present insufficient evidence. Further well-designed studies are warranted in the future.

Retrospective Analysis of Sagittal Balance Parameters and Clinical Efficacy After Short-Segment Anterior Cervical Spine Surgery with Different Fusion Devices

Objective

To compare the cervical sagittal balance parameters and clinical efficacy of three fusion devices after short-segment anterior cervical discectomy and fusion.

Patients and Methods

Retrospectively analyzed 516 patients with cervical spondylosis who underwent surgery at our hospital from May 2013 to May 2019. All patients had complete data and were divided into three groups according to the selected fusion cage. Neck and upper limb pain were assessed by the visual analog scale (VAS) score. Neurological function was evaluated by the modified Japanese Orthopedics Society (mJOA) score. Also, the curvature of the cervical spine and the occurrence of dysphagia were observed.

Results

There were no significant differences in the general information, thoracic inlet angle, T1 slope, or surgical data among the groups (p>0.05). There were significant differences in the scores between pre- and postoperatively in the different groups (p<0.05). There were no significant differences in the C2-C7 Cobb angle or C2-C7 sagittal vertebral axis before the operation among the groups (p>0.05). There was a significant difference in the correction and loss of correction among the groups postoperatively and on follow-up (p>0.05). Dysphagia was less likely in the Zero-P VA fusion group than in the other two groups.

Conclusion

Different fusion instruments can relieve the symptoms. In the Prodisc-C Vivo group, no significant improvement in cervical sagittal balance was achieved. A good effect on improving sagittal balance was observed in both the Zero-P VA fusion and Skyline anterior cervical titanium plate groups, but a better effect on preventing dysphagia was observed in the Zero-PVA fusion group.

Comparison of Zero-profile Anchored Spacer Versus Plate-and-Cage After 1-Level ACDF With Complete Uncinate Process Resection: A 3-Year Assessment of Radiographic and Clinical Outcomes

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

The purpose of this study is to compare the zero-profile anchored spacer device (Zero-p) and traditional plate-and-cage implant (plate-and-cage) in anterior cervical discectomy and fusion (ACDF) with complete uncinate process resection (UPR) to treat 1-level cervical degenerative disk disease.

SUMMARY OF BACKGROUND DATA

We retrospectively surveyed the data from all patients who underwent single-level ACDF with complete UPR between 2009 and 2013.

PATIENTS AND METHODS

In total, 80 patients participated in 3 years of follow-up. Among them, Zero-p (38 patients) and plate-and-cage (42 patients) approaches were used in ACDF with complete UPR. Clinical outcomes and radiographic results were compared between 2 groups and they were followed for 39.1±2.2 months.

RESULTS

Duration of operation, intraoperative blood loss, and length of hospitalization were significantly lower in the Zero-p group than the plate-and-cage group (P<0.001). The clinical outcomes of visual analog scale, neck disability index, and the Odom criteria were improved after operation in both groups. The fusion rates, C2-C7 lordosis, T1 slope, C2-C7 sagittal vertical axis, sellar turcica-C7 sagittal vertical axis, and spinocranial angle after single-level ACDF were not significantly different between the 2 groups. Subsidence occurred in 5 cases (13%) in the Zero-p group and 10 cases (37%) in the plate-and-cage group (P<0.05). The horizontal length of the Zero-p implant was longer than that of allograft bone. Fusion occurred in 37 cases (95%) of the Zero-p group and 40 cases (94%) in the plate-and-cage group.

CONCLUSIONS

The Zero-p and plate-and-cage are effective when single-level ACDF with complete UPR was performed. Both groups showed good clinical outcomes, but Zero-p has more benefits than plate-and-cage such as lower duration of operation, intraoperative blood loss, length of hospitalization, and rate of subsidence compared with plate-and-cage. Surgeons should be aware of these results so that postoperative complications such as subsidence can be avoided.

Outcomes After Cervical Disc Arthroplasty Versus Stand-Alone Anterior Cervical Discectomy and Fusion: A Meta-Analysis

STUDY DESIGN

Systemic review and meta-analysis.

OBJECTIVES

To review and compare surgical outcomes for patients undergoing stand-alone anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA) for the treatment of cervical spine disease.

METHODS

A systematic search was performed on PubMed, Medline, and the Cochrane Library. Comparative trials measuring outcomes of patients undergoing CDA and stand-alone ACDF for degenerative spine disease in the last 10 years were selected for inclusion. After data extraction and quality assessment, statistical analysis was performed with R software metafor package. The random-effects model was used if there was heterogeneity between studies; otherwise, the fixed-effects model was used.

RESULTS

In total, 12 studies including 859 patients were selected for inclusion in the meta-analysis. Patients undergoing stand-alone ACDF had a statistically significant increase in postoperative segmental angles (mean difference 0.85° [95% confidence interval = 0.35° to 1.35°], P = .0008). Patients undergoing CDA had a decreased rate of developing adjacent segmental degeneration (risk ratio = 0.56 [95% confidence interval = -0.06 to 1.18], P = .0745). Neck Disability Index, Japanese Orthopedic Association score, Visual Analogue Scale of the arm and neck, as well as postoperative cervical angles were similar between the 2 treatments.

CONCLUSIONS

When compared with CDA, stand-alone ACDF offers similar clinical outcomes for patients and leads to increased postoperative segmental angles. We encourage further blinded randomized trials to compare rates of adjacent segmental degeneration and other postoperative outcomes between these 2 treatments options.

Association of complete uncinate process removal on 2-year assessment of radiologic outcomes: subsidence and sagittal balance in patients receiving one-level anterior cervical discectomy and fusion

Background

Many patients with cervical radiculopathy experience stenosis of the neural foramens due to cumulative osteophyte or uncovertebral joint hypertrophy. For cervical foraminal stenosis, complete uncinate process resection (UPR) is often conducted concurrently with anterior discectomy and fusion (ACDF). The aim of this study was to assess the clinical and radiological outcomes of ACDF with complete UPR versus ACDF without UPR.

Methods

In total, 105 patients who performed one-level ACDF with a cage-and-plate construct between 2011 and 2015 were retrospectively reviewed. Among them, 37 patients had ACDF with complete UPR, and 68 patients had ACDF without UPR. Radiologic outcomes of disc height, C2–C7 lordosis, T1 slope, C2–C7 sagittal vertical axis (SVA), center of the sella turcica–C7 SVA (St-SVA), spino-cranial angle (SCA), and fusion rate were evaluated on plain X-ray at pre-operation, immediately post-operation, and at 2-year follow-up. For statistically matched pairs analysis, ACDF with UPR group (24 patients) and ACDF without UPR (24 patients) were compared.

Results

All of the clinical parameters improved at the 2-year follow up (P < 0.0001). Improvement in visual analogue scale (VAS) scores for arm pain was significantly improved in the ACDF with complete UPR group immediately post-operation. All cervical sagittal parameters, including cervical lordosis, segmental angle, disc height, C2-C7 SVA, St-SVA, T1 slope, and SCA, except for preoperative St-SVA, SCA, and disc height of 2 years follow-up, were similar between the ACDF with complete UPR and ACDF without UPR groups. Differences in disc height, C2-C7 SVA, and SCA at 2-year follow up after preoperative examination, however, were statistically significant (p < 0.05). Subsidence occurred in 9 patients (ACDF with complete UPR: 8 cases [33%] versus ACDF without UPR: 1 cases [4%]; p < 0.05).

Conclusions

Cervical sagittal alignment after ACDF with complete UPR is not significantly different from that achieved with ACDF without UPR. However, subsidence appears to occur more often after ACDF with complete UPR than after ACDF without UPR, although with little to no clinical impact. More precise and careful selection of patients is needed when deciding on additional complete UPR.

The association of cervical sagittal alignment with adjacent segment degeneration

Purpose

Cervical spine surgery may affect sagittal alignment parameters and induce accelerated degeneration of the cervical spine. Cervical sagittal alignment parameters of surgical patients will be correlated with radiological adjacent segment degeneration (ASD) and with clinical outcome parameters.

Methods

Patients were analysed from two randomized, double-blinded trials comparing anterior cervical discectomy with arthroplasty (ACDA), with intervertebral cage (ACDF) and without intervertebral cage (ACD). C2–C7 lordosis, T1 slope, C2–C7 sagittal vertical axis (SVA) and the occipito-cervical angle (OCI) were determined as cervical sagittal alignment parameters. Radiological ASD was scored by the combination of decrease in disc height and anterior osteophyte formation. Neck disability index (NDI), SF-36 PCS and MCS were evaluated as clinical outcomes.

Results

The cervical sagittal alignment parameters were comparable between the three treatment groups, both at baseline and at 2-year follow-up. Irrespective of surgical method, C2–C7 lordosis was found to increase from 11° to 13°, but the other parameters remained stable during follow-up. Only the OCI was demonstrated to be associated with the presence and positive progression of radiological ASD, both at baseline and at 2-year follow-up. NDI, SF-36 PCS and MCS were demonstrated not to be correlated with cervical sagittal alignment. Likewise, a correlation with the value or change of the OCI was absent.

Conclusion

OCI, an important factor to maintain horizontal gaze, was demonstrated to be associated with radiological ASD, suggesting that the occipito-cervical angle influences accelerated cervical degeneration. Since OCI did not change after surgery, degeneration of the cervical spine may be predicted by the value of OCI.

NECK trial

Dutch Trial Register Number NTR1289.

PROCON trial

Trial Register Number ISRCTN41681847.

Graphic abstract

These slides can be retrieved under Electronic Supplementary Material.

Correlation between cervical lordosis and cervical disc herniation in young patients with neck pain

Abnormal cervical curvature and cervical disc herniation are closely related to neck pain and should be taken into account before any treatment. However, studies have rarely reported on the correlation between cervical lordosis and cervical disc herniation in patients with neck pain. Therefore, in this study, we collect young neck pain patients with abnormal cervical curvature to evaluate the relationship between cervical lordosis and cervical disc herniation.Three hundred patients below 40 years old with neck pain were enrolled. Patient sex, age, apical vertebra, segment of intervertebral disc protrusionl, sagittal diameter of spinal duramater, saggital diameter of spinal canal, height of disc space were recorded, and the cervical curvature, and degree of cervical spinal cord compression (G/F ratio) were calculated. The change of degree of disc herniation and degree of cervical spinal cord compression were analyzed in different cervical curvature groups. Further more, collected these patients who had improved cervical curvature over a period of time, to compare the changes of degree of disc herniation, G/F ratio, and height of disc space.The median age of patients with kyphosis was lower than those with lordosis and straight cervical spine. The degree of disc herniation was higher in the straight and kyphosis groups compared to the lordosis group. Cervical lordosis was inversely correlated with the degree of disc herniation and positively with G/F ratio. Cervical curvature was significantly affected by sex, age, and the degree of disc herniation. With the improvement of cervical lordotic curvature, the degree of disc herniation decreased and height of disc space increased.The degree of disc herniation and cervical spinal cord compression are inversely correlated to cervical lordosis in young neck pain patients, and the degree of disc herniation and height of disc space can recover with the recovery of cervical lordotic curvature. These findings may indicating a link between cervical curvature and degenerative changes which have important clinical implications.

Endoscopic Anterior Approach for Cervical Disc Disease (Disc Preserving Surgery)

OBJECTIVE

To report our experience of endoscopic disc removal by anterior approach for management of cervical myelopathy in 210 patients.

METHODS

A retrospective study of 187 cases of single- and 23 cases of double-level disc disease was performed. Cases of myelopathy with or without unilateral or bilateral radiculopathy and unilateral radiculopathy with either soft or hard disc prolapse were included. Patients with ≥3 disc levels, unstable spine, infections, trauma, significant posterior compression, congenital canal stenosis, disc extending more than half the vertebral body height, and prior surgery at the same level were excluded.

RESULTS

C5-6 (n = 119 patients), C6-7 (n = 58 patients), C4-5 (n = 49 patients), C3-4 (n = 6 patients), and C2-3 (n = 1 patient) levels were represented. Visual analog scale and Nurick grading system were used to assess severity of neck and arm pain and functional outcomes, respectively. Preoperative mean visual analog scale scores for arm and neck pain were 6.7 and 3.2, respectively, which improved to 1.7 and 1.1 at 3 months after surgery. The average preoperative Nurick grade improved from 2.64 to 0.81 at 6 months postoperatively. Follow-up was 6-54 months.

CONCLUSIONS

Endoscopic anterior discectomy (disc preserving surgery) is an effective and safe alternative in cervical disc disease. Although there was reduction in disc height, clinical outcome was good at an average 29 months of follow-up. Long-term follow-up is required to assess any progressive disc degeneration and clinical results.