The preliminary changes of sagittal balance of cervical spine after posterior cervical intermuscular raising roof laminoplasty

English Keywords:Cervical spondylotic myelopathy  Posterior cervical laminoplasty  Intermuscular approach  Raising roof  Sagittal balance of cervical spine  Cervical range of motion

English Abstract:

  【Abstract】 Objectives: To explore the preliminary clinical effects of multilevel cervical spondylotic myelopathy(CSM) by posterior cervical intermuscular raising roof laminoplasty. Methods: 75 patients with multilevel cervical spondylotic myelopathy underwent posterior cervical laminoplasty at our hospital between August 2013 and September 2020 were recruited in this retrospective study. Of all patients, 42 treated with posterior cervical intermuscular "raising roof" laminoplasty were included in the raising roof group(mean age, 57.2±10.7 years; ranged 31 to 79 years), and 33 underwent posterior single open-door laminoplasty by traditional suture suspension fixation were included in the suture suspension group(mean age, 67.2±9.6 years; range 48 to 82 years). All patients were followed up at 3-14 months after surgery at the outpatient department. The basic hospitalization information of the patients in the two groups were collected; Cervical sagittal balance parameters, including C0-2 Cobb angle, C2-7 Cobb angle, C2-7 sagittal vertical axis(C2-7 SVA), C7-Slope, and cervical range of motion (ROM) were measured on X-ray images before the operation and at the last follow-up. The modified JOA(mJOA) score, visual analogue scale(VAS) score and neck disability index(NDI) were evaluated before the operation and at the last follow-up, and the mJOA score recovery rate was calculated. Results: There were no significant differences in terms of gender, intraoperative blood loss, and the mean follow-up time between the two groups(P>0.05). The age and postoperative hospital stay of patients in the raising roof group were smaller than those of the suture suspension group(P<0.05). There were no significant differences in preoperative C0-2 Cobb angle, C2-7 Cobb angle, C2-7 SVA, C7-Slope and cervical ROM(P>0.05). C7-Slope and C2-C7 SVA of the raising roof group were smaller than those in suture suspension group at the last follow-up(P<0.05), while C2-7 ROM in the raising roof group was better at the last follow-up(P<0.05). The mJOA and VAS scores of both groups at the last follow-up were significantly improved than those before operation, and the differences were of statistical significance. There was no significant difference in mJOA and VAS scores between the two groups at the same time point(P>0.05), nor was there significant difference in mJOA score improvement rate(P>0.05). The NDI of both groups at the last follow up were not improved significantly than those before operation(P>0.05), also there was no statistical significance between the two groups at the same time point(P>0.05). Conclusions: Posterior cervical intermuscular raising roof laminoplasty can achieve the same neurological function improvement as the traditional posterior cervical single open-door laminoplasty in the early stage after operation in the treatment of multilevel CSM, and besides, it has more advantages in maintaining sagittal balance and cervical range of motion.