Stand-Alone Cervical Cages in 2-Level Anterior Interbody Fusion in Cervical Spondylotic Myelopathy: Results from a Minimum 2-Year Follow-up

Abstract

Study Design A retrospective review of patients who underwent 2-level anterior cervical discectomy and fusion (ACDF) with standalone polyetheretherketone (PEEK) cages for cervical spondylotic myelopathy (CSM). Purpose To evaluate the efficacy of stand-alone PEEK cage in 2-level cervical interbody fusion for CSM. Overview of Literature ACDF is a standard surgical procedure to treat degenerative disc disease. However, the use of additional anterior plating for 2-level ACDF remains controversial. Methods We reviewed outcomes of patients who underwent 2-level ACDF with stand-alone PEEK cages for CSM over a 7-year period (2007–2015) in a regional hospital. Japanese Orthopaedic Association (JOA) score, fusion rate, subsidence rate, cage migration, and cervical alignment by the C2–7 angle as well as the local segmental angle (LSA) of the cervical spine were assessed. Results In total, 31 patients (mean age, 59 years; range, 36–87 years) underwent 2-level ACDF with a cage-only construct procedure between 2007 and 2015. The minimum follow-up was 24 months; mean follow-up was 51 months. C3–5 fusion was performed in 45%, C4–6 fusion in 32%, and C5–7 fusion in 23%. Mean JOA score improved from 10.1±2.2 to 13.9±2.1 ( p <0.01) at the 24-month follow-up. Fusion was achieved in all patients. Subsidence occurred in 22.5% of the cages but was not associated with differences in JOA scores, age, sex, or levels fused. Lordosis of the C2–7 angle and LSA increased after surgery, which were maintained for up to 1 year but subsequently disappeared after 2 years, yet the difference was not statistically significant. No cage migration was noted; two patients developed adjacent segment disease requiring posterior laminoplasty 3 years after ACDF. Conclusions The use of a stand-alone PEEK cage in a 2-level cervical interbody fusion achieves satisfactory improvements in both clinical outcomes and fusion.

Biomechanical Study of Cervical Endplate Removal on Subsidence and Migration in Multilevel Anterior Cervical Discectomy and Fusion

“…One biomechanical mechanism for relatively high fusion rates with standalone cervical interbody may be the reduction of stress shielding from the elimination of the anterior plate and an increase in compressive forces described by Wolff 's law [12]. Literature generally considers cage distraction a minute issue in the long term due to minimal patient discomfort and comparable fusion success rates [13]. These short-term issues of stability and misalignment and resulting problems combined with some fusion failures establish a case for the inclusion of exterior support methods to re-distribute and reduce the load at the cage-vertebra contact surface.…”

Comparison of Radiological Outcome in Anterior Cervical Discectomy and Fusion: Cage-Only v/s Cage and Plate Fixation

“…Statistics on whether ASD is naturally occurring development of adjacent osteoarthritis and thus ACD-related, or is a result of a postoperative biomechanical change, is controversial and little known. Stated causing aspects comprise the incidence of ASD before surgical procedure, excessive dispersion of disc space and amplified range of motion at adjacent levels [20][21] . However, these causing aspects don't settle the dispute about the source of ASD.…”

A Retrospective Evaluation and Review of Outcomes for Single- and Multilevel ACDF With a Zero-Profile Stand-Alone Cage Device With Integrated Instrumentation

“…As a result, stand-alone cages without instrumentation were developed, but they presented issues regarding subsidence and fusion rates. Ng et al highlighted the model’s subsidence rate to be 22.5% [ 11 ]. We propose that zero-profile cage systems with instrumentation and screw fixation should be considered viable options for ACDF due to their effective design and promising results.…”