Commentary Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed procedures in spine surgery. Clinical results have demonstrated that ACDF may be effectively utilized for a wide variety of indications, including degenerative spine conditions and spinal instabilities, as well as for the treatment of neural compression syndromes. One of the drawbacks associated with this type of procedure is the occurrence of dysphagia and/or dysphonia in a relevant number of patients. Although studies have reported beneficial effects of systemic administration of methylprednisolone perioperatively1,2, the study by Jenkins et al. is novel because it is one of the first studies to compare the efficacy of local retropharyngeal corticosteroids with intravenous (IV) corticosteroid administration. In this study, both the IV and local corticosteroid treatment groups had significantly positive effects on the reduction of dysphagia, dysphonia, and neck pain following ACDF compared with the control group, with the local corticosteroid group demonstrating an even more pronounced effect. Conversely, in a prospective, randomized, single-blinded controlled trial, Haws et al. suggested that intraoperative local corticosteroid administration may not provide additional benefit to patients undergoing ACDF procedures3. Thus, further studies must be conducted to assess the clinical efficacy of local versus systemic corticosteroid administration. The data from this study have the potential to influence the practice patterns of surgeons, and also the way that physicians may deal with this type of adverse event following ACDF. Considering the effect that these results may have on the future of patient care, it is paramount to take a closer look at the data presented in this study and how it compares with data from other studies on the subject. Nonsteroidal anti-inflammatory drugs (NSAIDs) have previously been reported to reduce the occurrence of heterotopic ossification and have therefore been utilized therapeutically in a wide variety of orthopaedic settings, including the cervical spine (i.e., postoperatively following anterior cervical disc replacement)4,5. Conversely, a possible counterproductive effect has been reported in situations in which a solid fusion and osteointegration of implants is the main aim, which explains why these substances are under close scrutiny following procedures such as ACDF6. Likewise, local corticosteroids have been associated with impaired wound healing and esophageal or pseudarthrosis complications, particularly when administered locally in the retropharyngeal space7. Unlike a systemic administration of NSAIDs, the application of the corticosteroids into the retropharyngeal space disperses a substantial amount of the drug directly into the targeted intervertebral disc space, surrounding both implants as well as the cortical/cancellous bone of the adjacent vertebral bodies. Therefore, it needs to be assessed and closely monitored whether the reduction in dysphagia and dysphonia may come at a tradeoff of raised nonunion rates in the medium and long term. As outlined by Jenkins et al., the study design and the power of the study did not permit a sound analysis of the rates of union versus nonunion, and hence this essential question cannot be answered in this present setting. In the local corticosteroid group, there were 29 patients with a mean age of 55.6 years (minimum age, 18 years), and patients were excluded for a variety of reasons (e.g., any revision procedure, general metabolic disease, etc.), which resulted in a ‘perfect cohort’ to achieve fusion. Additionally, all patients in the study received additional cervical plating, which should ultimately result in improved fusion rates. These aspects of the study design show that, by cohort definition as well as by the type of instrumentation used, the present patient sample is, in fact, characterized by an optimal predisposition to achieve a solid fusion. Nevertheless, 2 patients in the entire study were diagnosed with pseudarthrosis, with both cases belonging to the local corticosteroid group. Because the limited number of patients does not permit any valid statistical analysis, it is critical that future studies investigate whether these initial results may point to a larger underlying issue of reduced fusion rates related to local corticosteroid application into the retropharyngeal space. Overall, Jenkins et al. are to be congratulated for their substantial efforts with this well-designed study that assesses potential treatment modalities for a frequently underappreciated adverse event following ACDF. Future studies will need to investigate whether or not this positive effect of dysphagia and dysphonia reduction following retropharyngeal administration of local corticosteroids comes at a tradeoff with higher pseudarthrosis/nonunion rates, whether this local administration will coincide with a higher risk of complications such as esophageal perforations, and whether improved clinical results can actually be confirmed in the medium and long term.
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Jan 1, 2019
Kenji Kutara + 7
Open Access
