Long-term follow-up prognosis and influencing factors analysis of neurological deterioration during early stage after laminoplasty

English Keywords:Expansive open-door laminoplasty  Preservation of unilateral muscle-ligament complex  Neurological deterioration  Long-term follow-up

English Abstract:

  【Abstract】 Objectives: To explore the long-term follow-up prognosis and risk factors in patients with neurological function deterioration after expansive open-door laminoplasty at early postoperative stage(within 3 months). Methods: A retrospective analysis was conducted on 17 patients who experienced neurological function deterioration(the mJOA score decreased by ≥1 point at postoperative 3 months′ follow-up compared with that before operation) at early stage after receiving laminoplasty with the preservation of unilateral muscle-ligament complex in our department between January 2006 and December 2012. The patients were divided into non-recovery group(n=5) and recovery group(n=12) based on whether the mJOA score of one patient recovered to one′s preoperative level at postoperative 10-year follow-up. The baseline data, perioperative information, postoperative 3-month, 1-year and 10-year mJOA score, neck disability index(NDI) score, and visual analog scale(VAS) score, as well as the imaging data[Cobb angle, range of motion(ROM) of the cervical spine, and sagittal vertical axis(SVA) of C2-C7] were collected and compared for regression analysis. The differences between different mJOA categories involved between the two groups were also compared. Results: The proportion of patients with ossification of longitudinal ligament(OPLL) in the non-recovery group was significantly higher than that in the recovery group. There were no statistically significant differences between the two groups in baseline information such as age, gender, BMI, comorbidities, spinal cord T2 high singnal intensity and developmental cervical canal stenosis, as well as perioperative information such as operative time, blood loss and the length of hospital stay(P>0.05). One patient in the non-recovery group had experienced cerebrospinal fluid leakage and C5 nerve root palsy and 1 patient in the recovery group had experienced cerebrospinal fluid leakage, and the difference wasn′t with statistical significance between the two groups. After neurological deterioration occurred within postoperative 3 months, imaging examinations were conducted on all the patients and found none insufficient decompression, therefore no secondary surgical treatment was performed. The preoperative mJOA scores of the non-recovery group and recovery group were 13.30±2.46 and 14.71±1.41, respectively, with no statistically significant difference between the two groups. After early postoperative neurological function deterioration, the mJOA score at 1-year follow-up in the recovery group significantly improved compared to that at 3-month follow-up, which wasn′t significantly different from the preoperative level, and the mJOA score at 10-year follow-up was significantly higher than the values before surgery and at previous follow-up visits. However, in the non-recovery group, the 1-year and 10-year follow-up mJOA scores weren′t statistically different from the value at 3-month follow-up. There was no statistically significant difference in VAS scores and NDI scores between the two groups before surgery and at each follow-up; The intragroup comparison of VAS scores and NDI scores in both groups showed no significant difference between different time points. In the recovery group, the Cobb angle increased at each follow-up compared to the preoperative value, and SVA increased significantly at the 10-year follow-up. In the non-recovery group, there was no statistically significant difference in Cobb angle and SVA at each follow-up compared with the preoperative values. The ROMs at postoperative follow-up visits of the recovery group decreased significantly compared to that of preoperation, while no such difference was found in the non-recovery group. In addition, there were no significant differences in Cobb angle, ROM, and SVA between the two groups at preoperation and each follow-up. It was found that the patients in the non-recovery group were more likely to have the sensory function of lower extremity affected in neurological deterioration at postoperative early stage. The logistic regression results suggested that OPLL before operation was a risk factor for early postoperative neurological deterioration that was hard to recovery at 10 years of follow-up. Conclusions: The patients with cervical OPLL before operation who suffer from early postoperative neurological deterioration after laminoplasty tend to be more difficult to recover in the long-term follow-up.