Treatment of cervical ossification of the posterior longitudinal ligament by modified laminoplasty with C3 laminectomy and C7 spinous process retention

Objective To observe the clinical efficacy of modified laminoplasty with C3 laminectomy and C7 spinous process retention in the treatment of cervical ossification of the posterior longitudinal ligament(OPLL). Methods From Febru-ary 2014 to March 2016, 133 cases of OPLL were admitted, and 42 OPLLs were included according to the inclusion and exclusion criteria. A case-control study was conducted. Twenty-two cases were included in modified group and 20 cases in traditional group. There were 13 males and 9 females in the modified surgery group, and the average age was 56.2±9.75 years (39-77 years).Modi-fied surgery was conducted with C3 laminectomy, C4-C6 laminoplasty, resection at the upper part of the C7 lamina and retaining the C7 spinous process. Meanwhile, there were 12 males and 8 females in the traditional surgery group, with an average age of 53.7±8.23 years (41-75 years). Patients in the traditional surgery group were treated with standard C3-C7 laminoplasty. The mean follow-up was 22.9±4.5 (15-29) months. The JOA, NDI scores of the two groups were recorded preoperatively and postoperatively. The physiological curvature and activity of the cervical spine before and after operation were observed, and the incidence of axonal symptoms and postoperative complications in both groups were recorded. Results The follow-up period was 15-28 months, with an average of (23.2 ± 4.8) months. There was no significant difference between the base line of two groups before operation. At the last follow-up, the JOA and NDI scores of the two groups were significantly improved. There was no difference of JOA scores be-tween the two groups at the last follow-up, while the NDI sores at the modified group(6.56±4.78) was superior to the traditional group(9.25±7.63). The VAS score at the first day after surgery in modified group was lower than that of the traditional group. The average cervical curvature of the patients in the modified surgery group and the standard surgery group were 12.32°±8.26° and 11.56°±8.05°, respectively. There was no significant difference between the two groups. The postoperative range of movement (ROM) of cervical spine was 39.68°±9.52° in modified group and 33.51°±10.39° in traditional group(P<0.05). Eight patients (19%) had augmentation of axial symptoms, including 3 patients in the modified surgery group(13.6%) and 5 patients in the stan-dard surgery group (30%). There was no significant difference between the two groups. During the follow-up period, there were no complications such as cerebrospinal fluid leakage, spinal cord injury, wound infection, laminar collapse, postoperative closure, in-ternal fixation loss or fracture. Conclusion The modified laminectomy with C3 laminectomy and C7 spinous process retentionis minimally invasive, whichachieved satisfactory decompression effect, reduced the incidence of postoperative axial symptoms and maintained the cervical ROM. Key words: Cervical vertebrae; Ossification of posterior longitudinal ligament; Decompression, surgical