A novel revision surgery for treatment of cervical ossification of the posterior longitudinal ligament after initial posterior surgery: preliminary clinical investigation of anterior controllable antidisplacement and fusion

BACKGROUND: Cervical ossification of the posterior longitudinal ligament (OPLL) is a progressive disease. Posterior decompression surgery is reported to be an effective and comparatively safe procedure with few complications for treatment of patients with myelopathy caused by OPLL. However, some patients require revision surgery because of late neurological deterioration due to OPLL progression or kyphotic changes in cervical alignment. This study reports preliminary clinical results of anterior controllable antidisplacement and fusion (ACAF), a novel revision surgery after initial posterior surgery for OPLL. METHODS: From January 2017 to June 2018, ten patients with cervical OPLL who underwent ACAF revision surgery after initial posterior surgery were included in this study. The mean age was 62.1 ± 8.0 years (52–78), and the mean interval between initial posterior surgery and revision was 78.0 ± 48.2 months (5–180). The Japanese Orthopaedic Association (JOA) scales, Neck Disability Index (NDI), visual analog scale (VAS), and surgical complications were recorded. RESULTS: The mean surgery time was 179.3 ± 41.8 min (120–240), and the mean blood loss was 432.5 ± 198.3 ml (225–850). The patients were followed up for at least 12 months. The JOA scores improved from 8.7 ± 2.8 to 13.4 ± 2.4; the mean improvement rate was 59.9% ± 16.1%. Postoperative NDI and VAS scores were 13.3 ± 3.7 and 2.0 ± 1.6, respectively, and were significantly improved compared to those before the procedure (P < 0.05). Cervical lordosis improved from 3.8 ± 4.3° to 17 ± 4.6° after revision surgery. There was only one instance of cerebrospinal fluid (CSF) leakage; no instances of postoperative hematoma, C5 root palsy, or hoarseness occurred. CONCLUSIONS: The present study demonstrates that excellent postoperative outcomes can be achieved with the ACAF technique for revision treatment of OPLL. Though further study is required to confirm the conclusion, this novel technique has the potential to serve as an alternative surgical technique for revision treatment of OPLL.