In this study, we introduced a newly developed anterior cervical retractor system that is adjustable, stable, and does not require an assistant. We also analyzed the feasibility of microscopy-assisted ACDF using this system for the treatment of patients with CS. Our results showed that the VAS and NDI scores decreased significantly after surgery and decreased gradually over time to the final follow up, suggesting that pain and dysfunction were significantly improved, and daily activities were also improved. The JOA score increased postoperatively and continued to increase during follow-up, indicating that sensation and movement recovered well. Postoperative MRI confirmed adequate decompression of the spinal cord and nerve root, and radiography revealed sustained excellent cervical alignment and stability. Most importantly, no complications occurred in any of the patients, indicating the safety of the newly developed retractor system. In addition, both surgeons and assistants expressed good satisfaction with the retractor system, revealing good applicability.
In this study, the C2–7 Cobb angle variance was relatively large, which may be because we included patients with single, double, or triple levels of fusion. The C2–7 Cobb angle of patients with triple segments was usually significantly different from those of patients with a single segment, contributing to the large variance. Moreover, during follow-up, we observed a slight decrease in the C2–7 Cobb angle, which is consistent with previous reports [16]. The decrease in Cobb angle may be due to fusion cage sedimentation [1, 17]. A previous study found that patients managed with stand-alone cages were more prone to sedimentation than those treated with a plate and cage combination, and a higher subsidence rate was detected in patients who underwent surgery at levels C5–C7 than at levels C2–C5 [17]. We did not perform subgroup analysis due to limited case numbers.
As described, ongoing attempts have been made to improve the surgical exposure of the anterior cervical area, especially with retractor modification [8–10]. The poor stability and sustained difficulty of manual retraction can be overcome with a new modification. The retractor system used in this study had several advantages. First, it did not require additional force to maintain stability, which liberated the assistants and provided them with a clear view to observe and learn on the microscope screen, thereby improving their satisfaction and passion for joining the operation. Second, the exposed area was wide enough to guarantee the stability of the dissection planes between both the trachea and esophagus and the sternocleidomastoid and carotid sheath, which is critical for the exposure of herniated cervical disc tissue and the decompression of the spinal cord and nerve root [8]. With the development of microscopic technology, microscope-assisted surgery has attracted increasing attention in recent decades [18]. Microscopy has the advantage of clear identification of critical nerves and vessels in ACDF [2]; however, it also increases the need for the exposure area and stability of the dissection plane. Due to its improved exposure over human assistance, the newly developed retractor system is suitable for microscope-assisted ACDF. Third, the length of the retractor system could be adjusted according to the actual number of spinal levels. Notably, this performance is particularly important in procedures with longer incisions because a large incision has an increased risk of wound infection and patient dissatisfaction [19]. Fourth, the retractor system was assembled in a short time, which is convenient and economical. Its usage is simple and the learning curve is very short. Finally, compared to a previous study [20], the use of the newly developed retractor did not prolong the operative time, which was closely associated with prolonged non-home discharge, length of stay, and increased transfusion requirements after ACDF [21].
It is worth noting that several key points deserve attention during application, including complete hemostasis, gentle operation, and avoiding damage to vital organs and blood vessels during insertion and withdrawal of the K-wire.