ObjectiveTo evaluate the effectiveness of cervical single open-door laminoplasty with the unilateral C4,5 foraminotomy for cervical myelopathy in preventing postoperative C5 palsy. MethodsBetween January 2008 and June 2012, 200 consecutive patients with cervical myelopathy and unilateral C4,5 foraminal stenosis were treated, and the clinical data were retrospectively analyzed. Of them, 89 patients underwent cervical single open-door laminoplasty combined with unilateral C4,5 foraminotomy (group A), and 111 patients underwent simple cervical single open-door laminoplasty (group B). There was no significant difference in gender, age, disease duration, segmental lesions, and diagnosis distribution between 2 groups (P>0.05). The operation time, intraoperative bleeding volume, and the incidence of C5 palsy were recorded. The Japanese Orthopaedic Association (JOA) score before and after operation was used for neurological assessment, and the JOA recovery rate was calculated. ResultsThe operation time was (122±29) minutes and the intraoperative bleeding volume was (165±50) mL in group A, which were significantly higher than those in group B[(109±31) minutes and (145±32) mL] (t=3.033, P=0.010;t=3.429, P=0.003). All patients were followed up; the follow-up time was 3-48 months (mean, 25 months) in group A, and was 4-50 months (mean, 27 months) in group B. C5 palsy occurred in 1 patient of group A (1.12%), and in 9 patients of group B (8.11%), showing significant difference between 2 groups (χ2=3.709, P=0.045). The JOA score was significantly improved at 2 weeks and last follow-up after operation when compared with preoperative JOA scores in 2 groups (P<0.05), but no significant was found between at 2 weeks and at last follow-up (P>0.05) in each group. Between group A and group B, no significant difference was found in JOA score and the recovery rate (P>0.05). During follow-up, no persistent axial pain for a long time and obvious spinal instability occurred in 2 groups. ConclusionCervical single open-door laminoplasty with unilateral C4,5 foraminotomy can reduce the incidence of the C5 palsy for patients with cervical myelopathy combined with unilateral C4,5 foraminal stenosis.