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

Abstract

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). 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. The increase in OPLL thickness in the VBSO group (-0.18 ± 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. The solid fusion of the anterior column by VBSO is associated with the lower incidence of OPLL growth and potential for growth arrest.