The Effects Of Modified Cervical Posterior Laminoplasty In The Treatment Of Multi-segmental Cervical Spinal Canal Stenosis With Single Segmental Instability

Purposes To discuss the clinical effects of modified cervical posterior laminoplasty in the treatment of multi-segmental cervical spinal canal stenosis with short-segmental instability.Methods From April 2014 to January 2017,25 patients with multi-segmental cervical spinal canal stenosis and single segmental instability were treated with the modified cervical posterior laminoplasty including 18 males and 7 females,and the average age was 59.0 ± 6.6(47 to 70 years old).The average course of disease was 23.4±32.8months(3 to 120 months).The main clinical symptoms included limbs numbness and weakness,unstable gait,exquisite motion poor of upper limbs and so on because of the injury of cervical spinal cord or nerve root.Preoperative MRI,CT and hyperextension and flexion radiograph of the cervical spine clearly showed multi-segmental cervical spinal canal stenosis and single segmental instability.All patinets had accomplished preoperative examination to exclude surgical contraindications and were placed in a prone position with general anesthesia to receive the modified cervical posterior laminoplasty.The following parameters were evaluated as below: preoperative and final follow-up cervical lordotic angles(CLA)and cervical range of motion(C-ROM)were respectively measured to assess the loss of cervical curvature and ROM after surgery,and the Pavlov Ratio(PR),m JOA(modified Japanese Orthopedic Association sore,m JOA)and the rate of JOA improvement were used to evaluate the spinal canal opening and neurological recovery.Result Primary healing of incision was obtained in all patients.No internal fixation shift,reclosed open-door,axial pain and other related complications were observed during follow-up.The patients were followed up average 12-46 months(5~39 months).The X-ray examination showed all patients with good open laminae position,internal fixation without displacement or pull out,unstable segments fixed well and no instable inclination.The preoperative CLA was(15.2°± 8.2°)and the last follow-up CLA was(13.5°±7.8°)with no significant difference(P > 0.001).The preoperative ROM was(38.7°±8.5°)and the last follow-up ROM was(35.3°±7.6°)with no significant difference(P>0.001).The preoperative PR was(0.62±0.08)and the last follow-up PR was(0.83±0.07)that was significantly improving with significant difference(P<0.001).The preoperative m JOA score was 11.4±2.1 and the last follow-up m JOA was 14.7±1.5that was significantly improving with significant difference(P < 0.001).The final follow-up JOA improvement rate was 60.5%±20.3%,excellent and good rate reached84%.Conlusion Modified cervical posterior laminoplasty can effectively improve the neurological function of patients and preserve part of the CLA and C-ROM while reconstructing the stability of unstable segment.