ObjectiveTo compare the long-term effectiveness of wheather posterior ligamentous complex (PLC) preserved between posterior fenestration decompression interbody fusion and posterior total laminectomy interbody fusion. MethodsThe clinical data of 89 patients who suffered from single segmental degenerative diseases of lower lumbar spine and followed up more than 10 years after receiving lumbar spinal fusion between January 2000 and January 2005 were retrospectively analysed. The patients were divided into two groups according to the different surgical methods, the 33 patients in group A were treated with posterior lumbar fenestration decompression, interbody fusion, and internal fixation, while 56 patients in group B were treated with posterior total laminectomy resection decompression, interbody fusion, and internal fixation. There was no significant difference in gender, age, body mass index, type of lesion, disease duration, lesion segment, and preoperative Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS) score, and Cobb angle of lumbar lordosis between the two groups (P>0.05). The effectiveness was evaluated by JOA score, and the improvement of pain was evaluated by VAS score. The incidence of adjacent segment degeneration (ASD) at last follow-up was recorded. ResultsBoth groups were followed up 10-17 years (mean, 12.6 years). There were 3 cases (9.1%) in group A and 5 cases (8.9%) in group B complicated with cerebrospinal fluid leakage, showing no significant difference (χ2=0.001, P=0.979). There was no complication such as infection, nerve root injury, internal plant loosening or transposition in both groups. Intervertebral fusion was satisfactory in both groups. The fusion time in groups A and B was (3.4±1.2) months and (3.7±1.6) months respectively, and there was no significant difference between the two groups (t=0.420, P=0.676). At last follow-up, the JOA score and VAS score of the two groups were significantly improved when compared with preoperative ones (P<0.05); there was no significant difference in Cobb angle of lumbar lordosis before and after operation in group A (t=0.293, P=0.772), but the Cobb angle of lumbar lordosis in group B was significantly lost at last follow-up (t=14.920, P=0.000). At last follow-up, the VAS score and Cobb angle of lumbar lordosis in group A were significantly superior to those in group B (P<0.05); there was no significant difference in JOA score between the two groups (t=0.217, P=0.828). There were 3 cases (9.1%) in group A and 21 cases (37.5%) in group B complicated with ASD, showing significant difference between the two groups (χ2=8.509, P=0.004). ConclusionLong-term effectiveness of both groups was satisfactory, but in terms of maintaining lumbar lordosis and reducing the incidence of ASD, the lumbar fusion retaining PLC is superior to total laminectomy and lumbar fusion removing PLC.