Cervical disc replacement surgery: biomechanical properties, postoperative motion, and postoperative activity levels

The influence of preoperative 12-item veterans rand physical component scores on outcomes following cervical disc replacement

PURPOSE

To evaluate the influence of preoperative VR-12 physical component scores (PCS) on outcomes following cervical disc replacement (CDR).

METHODS

Patients undergoing elective CDR were retrospectively identified. Patient-reported outcomes (PROs) of interest included VR-12 PCS/VR-12 Mental Component Score (MCS)/9-Item Patient Health Questionnaire (PHQ-9)/Short Form-12 (SF-12) PCS and MCS/Patient-Reported Outcome Measurement Information System-Physical Function (PROMIS-PF)/Visual Analog Scale-Neck Pain (VAS-NP)/VAS-Arm Pain (VAS-AP)/Neck Disability Index (NDI). Baseline up to two-year postoperative scores were obtained (average follow-up: 9.2 ± 6.8months). Two cohorts were created: VR-12 PCS < 35 or VR-12 PCS ≥ 35. Improvements in scores from baseline to six weeks postoperatively and to final follow-up were calculated. Changes in scores were compared to previously reported thresholds to determine rates of minimum clinically important difference (MCID).

RESULTS

Of 127 patients, 64 were in the worse VR-12 PCS group. Patients with better VR-12 PCS were more likely to have private insurance (p = 0.034). When accounting for insurance differences, the worse VR-12 PCS group reported inferior NDI/VAS-NP/PHQ-9/PROMIS-PF/VR-12 PCS/SF-12 PCS at six weeks and final follow-up (p ≤ 0.015, all). The worse VR-12 PCS group reported greater improvements in VAS-AP and VR-12 PCS by six weeks and in NDI/VR-12 MCS/VR-12 PCS/SF-12 PCS by final follow-up (p ≤ 0.026, all). Patients with worse VR-12 PCS reported greater MCID achievement for VR-12 MCS and SF-12 PCS (p ≤ 0.034, both).

CONCLUSION

Following surgery, patients with worse VR-12 PCS report greater improvements in PROs, highlighting the increased relative impact of surgery for patients with worse baseline physical function. These findings can be used to optimize patient experience perioperatively and inform postoperative expectations.

Does Baseline Facet Arthropathy Influence Early Clinical and Radiographic Outcomes After Cervical Disc Replacement?

BACKGROUND AND OBJECTIVES

Severe facet arthropathy is generally a contraindication to undergoing cervical disc replacement (CDR) due to associated instability and potentially limited improvement in neck pain caused by arthropathy. This study evaluates the influence of facet arthropathy on radiographic/early clinical outcomes after CDR.

METHODS

One/two-level CDR patients from a single surgeon's prospectively maintained database created 2 cohorts based on facet arthropathy: grade 0-1 or 2-3 (milder/moderate arthropathy). Patient-reported outcome measures for neck disability, neck/arm pain, depressive burden, mental/physical health/function were obtained preoperatively and through final follow-up (average follow-up: 8.5 ± 6.5 months). Preoperative/postoperative radiographs measured segmental lordosis and C2-C7/segmental range of motion (ROM) and determined facet grade for each operative level. Demographic differences, perioperative variables, baseline patient-reported outcomes, and intercohort differences/changes for postoperative patient-reported/radiographic outcomes were determined.

RESULTS

Of 161 patients, 100 were in the milder arthropathy group. There were no differences in baseline patient-reported outcomes. Patients with moderate arthropathy reported superior 6-week 12-Item Veterans Rand Mental/Physical Composite Scores (P ≤ .047, all). By final follow-up, moderate patients reported better 12-Item Veterans Rand Mental/Physical Composite Scores/Patient-Reported Outcome Measurement Information System-Physical Function/Patient-Health Questionnaire-9 (P ≤ .049, all). Cohorts reported similar improvements in all patient-reported outcomes by 6 weeks/final follow-up. Those with more severe facet arthropathy had significantly shorter preoperative disc heights (P < .001). Accounting for baseline disc height differences, by final follow-up, moderate patients had lower segmental ROM (P = .036). There were no significant differences in radiographic measurement changes (P ≥ .264, all).

CONCLUSION

Postoperatively, patients with moderate facet arthropathy reported lower depressive burden, better mental health/physical function, and lower segmental ROM. However, this did not translate to inferior short-term clinical outcomes. Further study should be conducted on the relationship between clinical/radiographic outcomes in CDR patients with facet arthropathy.

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.

Trends in cervical disc arthroplasty and revisions in the Medicare database

Background

Due to increased postoperative complications with anterior cervical discectomy and fusion (ACDF), there has been an increasing interest in the use of cervical disc arthroplasty (CDA). Advancements in prosthetic designs and techniques have improved patient reported outcome measurements and minimized revision rates. There is a paucity in the literature regarding recent trends in CDA utilization and revision rates. The purpose of this study was to determine annual primary and revision CDA trends with the use of an administrative database.

Methods

A retrospective review from 2005-2014 was performed using the Medicare Standard Analytical Files from the PearlDiver supercomputer (PearlDiver Technologies, Fort Wayne, IN, USA). Patients who underwent primary CDA were queried using International Classification of Disease, ninth revision (ICD-9) and current procedural terminology (CPT) code 84.62 and 22856, respectively. Revision CDAs were queried using ICD-9 procedure code 84.66. Primary outcomes of this study included annual primary procedures, annual revision incidence (RI), and additional demographic data such as age, gender, geographic location, Charlson-Comorbidity Index (CCI); in addition to length of stay (LOS), cost, and reimbursement.

Results

The query returned 2,016 and 517 primary CDA and revision CDA procedures were performed in the Medicare database, respectively. The data showed that the CAGR of primary and revision CDA procedures to be 20.54% and 5.84% (P<0.001), respectively. RI and RB demonstrated a CAGR of -12.22% and -9.61%, respectively. Patients younger than the age of 65 represented the majority of the patients undergoing this procedure. Demographically, primary and revision CDAs were found highest in the South.

Conclusions

The data demonstrates a high rate of annual growth in CDA utilization (20.54%) and revision CDA (5.84%), indicating there is an increase demand for CDA in the United States. Compared to ACDF, patients who undergo CDA have improved patient reported outcome measurements and lower rates of postoperative complications.