ABSTRACT
Objective:
To investigate the mid-term
efficacy of Dynesys internal fixation and posterior lumbar interbody fusion (PLIF) in the
treatment of grade I degenerative lumbar
spondylolisthesis.
Methods:
From June 2014 to June 2016, 68 cases, in which 35
males and 33
females aged from 44-74 (55.3±7.5), of grade I degenerative lumbar
spondylolisthesis treated using Dynesys internal fixation were retrospectively analyzed. There were 8 cases of L 3, 52 cases of L 4 and 8 cases of L 5 with an average visual analogue scale (VAS) of 4.5±2.1. At the same
time, 72
patients were treated with posterior lumbar interbody fusion (PLIF). There were 37
males and 35
females aged from 46-76 (56.8±7.2), with 9 cases of L 3, 53 cases of L 4 and 10 cases of L 5. The VAS of this group was 4.4±2.3. The
operative time, intraoperative
blood loss, postoperative drainage volume and
complications were compared between the two groups.
Range of motion (ROM), disc height of stable segment and upper adjacent segment, adjacent segment degeneration between the two groups were evaluated. ASD, Oswestry disability index (ODI) score and
Japanese Orthopaedic
Association (JOA) score were also compared between the two groups.
Results:
The
patients in both groups were followed up. The follow-up
time of Dynesys group was 50-74 months, average 64.2±18.3 months, and the follow-up
time of PLIF group was 55-79 months, average 65.2±15.5 months. The operation
time [(120.5±21.0) min vs. (132.5±27.0) min, t=2.924, P=0.004], intraoperative
bleeding [(312.5±80.7) ml vs. (352.5±84.5) ml, t=2.861, P=0.005] and postoperative
drainage [(120.3±45.8) ml vs. (140.2±50.2) ml; t=2.446, P=0.016] in Dynesys group were significantly better than those in PLIF group. The differences were statistically significant. There was no significant difference in postoperative ROM of stable segment, ROM of upper segment, disc height of stable segment and adjacent segment between the two groups before operation. At 5 years postoperatively, there was statistically significant difference between the stable segment ROM (4.3°±1.6° vs. 0; t=22.809; P<0.001) and the upper segment ROM (10.5°±2.1° vs. 12.8°±2.2°; t=6.329, P<0.001). At 5 years postoperatively, ODI scores of the two groups were (11.25%±8.12%, 16.53%±9.23%), and JOA scores were (22.60±2.20, 19.01±2.34), which were significantly improved compared with those before
surgery, with statistically significant differences (ODI t=3.585, P<0.001; JOA t=9.340, P<0.001). There was no significant difference in the
incidence of symptomatic ASD between the two groups (8.8% vs. 16.7%, χ2=1.284, P=0.257) , but there was significant difference in the
incidence of
X-ray ASD between the two groups (2.9% vs. 13.9%, χ2=4.043, P=0.044) .
Conclusion:
Compared with PLIF, Dynesys internal fixation for degenerative lumbar
spondylolisthesis is a minimally invasive, safe and effective surgical
method to retard ASD; Compared with PLIF, adjacent segment degeneration can be reduced using Dynesys internal fixation.