Radiological Changes in Adjacent and Index Levels after Cervical Disc Arthroplasty

Abstract

Purpose The purpose of this retrospective study was to evaluate radiological and clinical outcomes in patients undergoing cervical disc arthroplasty (CDA) for cervical degenerative disc disease. The results may assist in surgical decision-making and enable more effective and safer implementation of cervical arthroplasty. Materials and Methods A total of 125 patients who were treated with CDA between 2006 and 2019 were assessed. Radiological measurements and clinical outcomes included the visual analogue scale (VAS), the Neck Disability Index (NDI), and the Japanese Orthopaedic Association (JOA) myelopathy score assessment preoperatively and at ≥2 years of follow-up. Results The mean follow-up period was 38 months (range, 25–114 months). Radiographic data demonstrated mobility at both the index and adjacent levels, with no signs of hypermobility at an adjacent level. There was a non-significant loss of cervical global motion and range of motion (ROM) of the functional spinal unit at the operated level, as well as the upper and lower adjacent disc levels, compared to preoperative status. The cervical global and segmental angle significantly increased. Postoperative neck VAS, NDI, and JOA scores showed meaningful improvements after one- and two-level CDA. We experienced a 29.60% incidence of heterotrophic ossification and a 3.20% reoperation rate due to cervical instability, implant subsidence, or osteolysis. Conclusion CDA is an effective surgical technique for optimizing clinical outcomes and radiological results. In particular, the preservation of cervical ROM with an artificial prosthesis at adjacent and index levels and improvement in cervical global alignment could reduce revision rates due to adjacent segment degeneration.

Emerging Technologies within Spine Surgery

“…These findings have been replicated in clinical studies with significantly less ROM at adjacent levels in hybrid constructs than in multilevel ACDF [113]. Following CDA, index-level ROM improves and is maintained at long-term follow-up [94,97,103,104,106,108,[114][115][116][117]. This preservation of native ROM at the index and adjacent levels may reduce future ASD development.…”

“…Similarly, dysphagia following single-level CDA was demonstrated to occur at lower rates compared to ACDF at 7-year follow-up [124]. HO formation following CDA is a known potential outcome, with variable incidence rates in the literature ranging from 0% to 75% [100,108,115,125]. Its clinical significance has yet to be established [126].…”

Restoration of Range of Motion in the Cervical Spine through Single-Segment Artificial Disc Replacement Using the Baguera®C Prosthesis

“…The patient cohort examined in the current study demonstrated significant improvements in all clinical outcome parameters (NDI, VAS, and JOA) in comparison to baseline levels. Previous studies have also verified similar favorable clinical outcomes at different observation periods, irrespective of the type of prosthesis implanted [19][20][21][22]. It has been suggested that higher pre-operative NDI scores are associated with a more pronounced C2-C7 sagittal vertical axis and reduced cervical lordosis [23].…”

Proposal for a classification system of radiographic bone changes after cervical disc replacement

“…Nevertheless, plain radiographic assessment remains the front-line patient assessment tool for cTDR [ 12 , 16 ]. Previous studies have underscored the need for classification of radiographic changes around cTDR including heterotopic ossification (HO) [ 17 , 18 ] and bone loss [ 12 , 19 ].…”