Clinical Application Of Modified Open-door Laminoplasty Together With Preservation Bilateral Of The Semispinalis Cervicis

Objective:To evaluate the clinical effect of traditional open-door laminoplasty and reserved bilateral semispinalis modified open-door laminoplasty for multiple segmental cervical spinal cord compression syndrome.Methods:From January 2013 to May 2014,we retrospectively analyzed the data of 66 cases with multiple segmental cervical spinal canal compression syndrome who underwent open-door laminoplasty in our hospital.Among them,36 cases in the group were treated by traditional open-door laminoplasty, the bilateral of C2 and C7 spinous ligaments and muscle tissue attachment were retained(Tradition group). Another 30 patients who underwent modified open-door laminoplasty together with preservation bilateral of the semispinalis cervicis(Improved group). Operative time and intraoperative blood loss were recorded.Visual Analogue Scale/Score(VAS),Japanese Orthopaedic Association Score(17-score method),Neck Disability Index(NDI),cervical curvature,range of motion of cervical vertebra and axial symptom severity were compared and analyzed before operation,three months after operation and last follow-up.Results: A total of 66 patients were followed 12-24 months, mean 17.10 ± 3.57 months in the tradition group and 16.40±2.57 in the improved group, no significant difference was found between the two groups(P>0.05). The operative time was 140.49 ± 36.57 min in tradition group and 122.35±46.57 min in improved group(P>0.05). The operative blood loss was 233.66 ± 165.39 ml in tradition group and 281.18 ± 208.11 ml in improved group(P>0.05).And no spinal cord injury, the door shaft fracture, cerebrospinal fluid leakage, epidural hematoma, infection, implant loosening or breakage and other complications. Two patients in tradition group and one patient in improved group were complicated with C5 nerve root palsy, which alleviated after symptomatic treatment. There was no significant difference in the recovery rates of JOA between 2 groups at last follow-up(P>0.05). No significant differences were found between 2 groups with respect to NDI score at preoperative and three months after operation(P>0.05), but at last follow-up, there was significant difference between two groups(P<0.05), as well as preoperative and last follow-up with respect to NDI score in each group(P<0.05). No significant difference was found between 2 groups with respect to VAS score at preoperative(P>0.05), but at three months after operation and last follow-up, there were significant differences between 2 groups(P<0.05), as well as preoperative and last follow-up with respect to VAS score in each group(P<0.05). At last follow-up, the reduce degree of cervical curvature was 3.73°± 1.38°in tradition group and 1.47°±1.01°in improved group(P<0.05). The reduce degree of neck ranges of motion was 6.63°±2.09°in tradition group and 4.53°± 1.70°in improved group at last follow-up(P<0.05). Postoperative development or deterioration of axial symptoms occurred in 30.56% of patients in tradition group and 3.33% of patients in improved group,showing statistically significant difference(P<0.05).Conclusion:Compared with the traditional single-door operation, this new modified open-door laminoplasty procedure retained the integrity of cervical rear structure, reduced the incidence of axial symptoms, loss of cervical curvature and range of neck motion.