Evaluation of Clinical and Radiological Outcomes of Anterior Cervical Hybrid Surgery for Multilevel Cervical Disc Disease.

Introduction While dealing with multilevel cervical disc disease, there is no consensus regarding the ideal treatment. Traditionally, anterior cervical discectomy and fusion (ACDF) has been the time-tested procedure with good outcomes for single-level pathologies, but it is associated with disadvantages, including disruption of the biomechanical environment, increased stresses on adjacent superior and inferior segments during movement, accelerated degeneration, and Adjacent Segment Disease (ASD). Cervical total disc replacement (TDR) has been proposed to prevent this by preserving the range of motion (ROM) at the level of pathology and reducing stresses on adjacent segments. However, as is the case with ACDF, the results of cervical TDR in multilevel cervical disc disease are inconsistent. As different levels are at different degrees of degeneration, hybrid surgery (HS) has been proposed as a combination of ACDF and TDR, which can theoretically preserve cervical spine movements and reduce abnormal loading at adjacent levels, thus preventing the ASD. However, clinical benefits are yet to be proven. Materials and methods We did a retrospective study of 20 patients who underwent HS at Stavya Spine Hospital and Research Institute. All patients were evaluated clinically and radiologically periodically for a minimum follow-up of two years. Demographic data and intra-operative findings and complications, if any, were noted from the patients' records. Clinical evaluation included Visual Analog Scale (VAS) score, Neck Disability Index (NDI) score, and modified Japanese Orthopaedics Association (mJOA) score. Radiologically, cervical spine lateral view radiographs were done to assess C2-C7 ROM, adjacent superior and inferior segment ROM, and any evidence of heterotrophic ossification (HO). Results Of the 20 patients included, the mean age was 41.3 ± 7.4 years (range 36-62 years). The mean operative time was 125.8 ± 20.5 minutes, with a mean intraoperative blood loss of 138 ± 62.6 mL. The average follow-up period was 4.6 ± 3.7 years (ranging from 12 to 28 months). All the patients had statistically significant clinical improvement in terms of VAS score, NDI score, and mJOA score. Radiologically, mean C2-C7 ROM was 38.2° ± 9.6°, mean ROM at the superior adjacent segment was 8.2° ± 3.9°, and the inferior adjacent segment was 9.6° ± 4.3°. None of the patients exhibited any evidence of HO. Conclusion HS for multilevel disc disease in the cervical spine is associated with good clinical outcomes in terms of VAS, NDI, and mJOA scores. Radiologically, the benefit of HS is highlighted in terms of preserving the movements at the level of pathology, which reduces abnormal adjacent segment loading and thus potentially reduces the incidence of ASD.