Fate of Ossification of Posterior Longitudinal Ligament Following Anterior Cervical Fusion: Progression of Cervical Ossification of Posterior Longitudinal Ligament After Vertebral Body Sliding Osteotomy or Laminoplasty

OBJECTIVE: In the treatment of ossification of posterior longitudinal ligament (OPLL)-induced cervical myelopathy, laminoplasty (LMP) is the most widely used surgical procedure. However, the progression of ossification masses is a well-known complication of LMP. This study aimed to investigate whether the novel anterior cervical decompression technique (vertebral body sliding osteotomy; VBSO) based on anterior column fusion suppresses the progression of OPLL compared with motion-preserving posterior decompression surgery (LMP). METHODS: All 77 consecutive patients (VBSO group, n = 33; LMP group, n = 44) who underwent VBSO or LMP for cervical OPLL at our institute between January 2012 and November 2017 were included. A total of 62 and 86 cervical motion segments in the VBSO and LMP groups were investigated, respectively. The OPLL thickness was measured twice ( immediate postoperative and final follow-up), and the change of OPLL thickness was compared between the 2 groups. RESULTS: The increase in OPLL thickness in the VBSO group (L0.18 +/- 0.24 mm) was significantly smaller than that in the LMP group (1.0 +/- 0.9 mm, P < 0.001). Interestingly, in some patients, suppressed OPLL progression and decreased OPLL thickness were observed. CONCLUSIONS: The solid fusion of the anterior column by VBSO is associated with the lower incidence of OPLL growth and potential for growth arrest.