A comparison of minimally invasive posterior cervical decompression and open anterior cervical decompression and instrumented fusion in the surgical management of degenerative cervical myelopathy

OBJECTIVE Minimally invasive posterior cervical decompression (miPCD) has been described in several case series with promising preliminary results. The object of the current study was to compare the clinical outcomes between patients undergoing miPCD with anterior cervical discectomy and instrumented fusion (ACDFi). METHODS A retrospective study of 74 patients undergoing surgery (45 using miPCD and 29 using ACDFi) for myelopathy was performed. Outcomes were categorized into short-term, intermediate, and long-term follow-up, corresponding to averages of 1.7, 7.7, and 30.9 months, respectively. Mean scores for the Neck Disability Index (NDI), neck visual analog scale (VAS) score, SF-12 Physical Component Summary (PCS), and SF-12 Mental Component Summary (MCS) were compared for each follow-up period. The percentage of patients meeting substantial clinical benefit (SCB) was also compared for each outcome measure. RESULTS Baseline patient characteristics were well-matched, with the exception that patients undergoing miPCD were older (mean age 57.6 +/- 10.0 years [miPCD] vs 51.1 +/- 9.2 years [ACDFi]; p = 0.006) and underwent surgery at more levels (mean 2.8 +/- 0.9 levels [miPCD] vs 1.5 +/- 0.7 levels [ACDFi]; p < 0.0001) while the ACDFi patients reported higher preoperative neck VAS scores (mean 3.8 +/- 3.0 [miPCD] vs 5.4 +/- 2.6 [ACDFi]; p = 0.047). The mean PCS, NDI, neck VAS, and MCS scores were not significantly different with the exception of the MCS score at the short-term follow-up period (mean 46.8 +/- 10.6 [miPCD] vs 41.3 +/- 10.7 [ACDFi]; p = 0.033). The percentage of patients reporting SCB based on thresholds derived for PCS, NDI, neck VAS, and MCS scores were not significantly different, with the exception of the PCS score at the intermediate follow-up period (52% [miPCD] vs 80% [ACDFi]; p = 0.011). CONCLUSIONS The current report suggests that the optimal surgical strategy in patients requiring dorsal surgery may be enhanced by the adoption of a minimally invasive surgical approach that appears to result in similar clinical outcomes when compared with a well-accepted strategy of ventral decompression and instrumented fusion. The current results suggest that future comparative effectiveness studies are warranted as the miPCD technique avoids instrumented fusion.