Adjacent segment degeneration after lumbar interbody fusion with percutaneous pedicle screw fixation for adult low-grade isthmic spondylolisthesis: minimum 3 years of follow-up.
BACKGROUND
Although favorable clinical outcomes have been reported for instrumented lumbar interbody fusion (LIF), adjacent segment degeneration (ASD) has been reported as a long-term complication after LIF.


OBJECTIVE
To investigate ASD after instrumented LIF performed at a single level and only for the homogeneous disease of adult low-grade isthmic spondylolisthesis.


METHODS
A total of 128 patients who had undergone LIF for the treatment of adult low-grade isthmic spondylolisthesis involving the lower lumbar spine at our institution between February 2001 and December 2004 were retrospectively reviewed by chart review and telephone survey. Of them, 103 patients with a minimum of a 36-month follow-up period were enrolled in this study. The mean age was 48.5 years. The average follow-up period was 59 months. Clinical and radiological data related to segmental lordosis (SL), whole lumbar lordosis, sacral slope, pelvic tilt, pelvic incidence, and L1 axis S1 distance were analyzed to identify significant risk factors for ASD.


RESULTS
The overall incidence of ASD was 10.6% (11/103). The incidences of radiographic and symptomatic ASD were 8.7% (9/103) and 1.9% (2/103), respectively. All patients improved clinically and functionally during the follow-up period. Postoperative SL, preoperative SL, whole lumbar lordosis, and L1 axis S1 distance were significant risk factors for ASD. Only SL was a significant risk factor for both the preoperative and postoperative states.


CONCLUSIONS
ASD may occur at a relatively lower incidence in adult low-grade isthmic spondylolisthesis compared with other degenerative lumbar spinal diseases. SL is significantly correlated with ASD, whereas mechanical alterations caused by LIF are less likely to affect the adjacent segment. Restoration of normal SL is important for preventing ASD, and long-term follow-up is necessary.
Department of Neurosurgery, Wooridul Spine Hospital, Seoul, South Korea.
Jun Seok
JS
Bae
Sang-Ho
SH
Lee
Jin-Sung
JS
Kim
Byungjoo
B
Jung
Gun
G
Choi
D000328:Adult; D000368:Aged; D001863:Bone Screws / Q000009:adverse effects*; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects*; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis / Q000209:etiology*; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000503:physiopathology*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000601:surgery*; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult