Posterior longitudinal ligament resection or preservation in anterior cervical decompression surgery

We reviewed the literature to determine differences in clinical outcomes for the removal or preservation of the posterior longitudinal ligament (PLL) in anterior cervical discectomy and fusion (ACDF). The outcomes are surgeon and case-dependent for both practices. A literature review was performed in PubMed from the years 1960 to 2014 to identify studies describing surgeries where the PLL was removed or preserved during ACDF. Searches were performed using Medical Subject Headings (MeSH) and references included in the reviewed articles were also considered. Additionally we searched recent articles that cited those from the original search. The search yielded 79 articles and 115 pertinent citations. These 194 articles were reviewed for specific discussions of PLL resection or preservation. Four articles containing 122 patients were included in the final analysis. In 69 patients the PLL was removed and in 53 the PLL was preserved. Both groups improved in clinical scores during follow up. One patient in the PLL removal group had a cerebrospinal fluid leak. MRI and correlative outcome data suggest that a non-ossified PLL itself does not contribute to significant cord compression. Postoperative MRI of patients with the PLL removed showed a larger spinal cord diameter. Resection of the PLL is safe and common in ACDF surgery but there does not appear to be a demonstrable clinical difference in patients where it is resected. The ultimate decision is likely surgeon and case-dependent. Randomized trials could further determine the importance of PLL removal in ACDF treated patients.