Friday, September 28, 2018 4:05 PM–5:05 PM abstracts: new concepts: cervical spine: 244. Which is better for C2 involved ossification of posterior longitudinal ligament (OPLL): Dome-like laminoplasty or double-door laminoplasty?

Abstract

BACKGROUND CONTEXT Dome-like laminoplasty technique was used in the treatment of OPLL with C2 involvement, but it is not clear if the dome-like laminoplasty has more advantages over the other techniques. PURPOSE To determine which is better for C2 involved ossification of OPLL between dome-like laminoplasty (DLL) and double-door laminoplasty (DDL). STUDY DESIGN/SETTING This is a retrospective study. PATIENT SAMPLE Twenty-four subjects underwent C2 dome-like laminoplasty or C2 double-door laminoplasty were included in the analysis. OUTCOME MEASURES The neurological function and axial neck pain were evaluated with Japanese Orthopaedic Association (JOA) score and visual analogue scale (VAS). METHODS The medical records and imaging were reviewed to determine the involved segment length, type of OPLL, surgical methods of decompression, perioperative complications, and surgical outcome after surgery. RESULTS The continuous type of ossification was observed in 5/9 patients and the mixed type in 7/3 patients before surgery in DLL/DDL group. The length of involved level or decompression was 5.2±0.5/6.3±0.4 levels and 5.4±0.7/6.3±0.4 levels in DLL group and DDL group, respectively. The high signal of spinal cord was observed in 9(75%) and 8(66.7%) patients respectively in DLL group and DDL group. The JOA score improved rapidly within 1 year and continued to improve for up to 2 years after surgery in both groups. The mean JOA score in DLL group increased from 8.3 (range 2–13) points before surgery to 13.8 (9–17) points, and the recovery rate was 68.4% at final follow-up. The mean JOA score in DDL group increased from 7.2 (0–16) to 13.17 (7–17), and the recovery rate was 66.7%. Postoperative neurological assessment by JOA score and recovery rate showed no statistically significant difference between two groups (P>.05). The recovery rate of the patients with intramedullary high intensity signal (HIS) was slightly lower than the patients without HIS at the final follow up in DDL group, while slightly higher in DLL group. However, these differences were not statistically significant (P>.05). The VAS score improved from 2.3±0.4 to 1.9±0.6 in DLL group whilst worsen from 3.3±0.8 to 4.3±0.6 in DDL group. There was a significant difference in the postoperative VAS score between two groups (P=.01). CONCLUSIONS For OPLL patients with C2 involvement, dome-like laminoplasty is a good option to achieve the equivalent decompression outcomes as double-door laminoplasty and prevent the postoperative axial neck pain.