Sang-Ho Lee, Byungjoo Chung, Ho-Yeon Lee, Song-Woo Shin

Department of Neurosurgery, Wooridul Spine Hospital, Seoul, Korea

Keywords: Joint instability; lumbar vertebrae/surgery/radiography; spinal stenosis/surgery; spondylolisthesis/ surgery.


Objectives: Interspinous ligamentoplasty (ILP) is a relatively new procedure designed to stabilize mild degenerative lumbar instability. We compared surgical outcomes of ILP, posterior lumbar interbody fusion (PLIF), and posterolateral fusion (PLF) and evaluated radiographic factors affecting the success of ILP.
Patients and methods: We retrospectively reviewed the clinical data of 103 patients who underwent decompressive laminectomy followed by PLIF (n=30; mean age 53.5 years), PLF (n=39; mean age 52.3 years), or ILP (n=34; mean age 55.0 years). All the patients had segmental instability due to grade I degenerative spondylolisthesis at L4-5. Radiographically, we measured facet angles, transverse articular dimension, disc height, the angle of displacement in flexion, and the percent of slippage. Clinical outcomes were evaluated according to the Macnab criteria. The mean follow-up periods were 36 months, 35 months, and 22 months in the PLIF, PLF, and ILP groups, respectively.
Results: The average duration of anesthesia, the length of the incision, the amount of blood loss, and the length of hospital stay were significantly more favorable in the ILP group. The clinical success (excellent or good) rate was 76.7% in the PLIF group, 82.0% in the PLF group, and 85.3% in the ILP group (p=0.67). No neurological complications, infections, or device failure were encountered in the ILP group. However, deep wound infections (n=2), major neurological complications (n=3), newly developed degenerative spondylolisthesis (n=1), and mortality due to surgery-associated complications (n=1) were seen in the PLIF group. Device failure developed in four patients in the PLF group. Successful outcomes following ILP were significantly correlated with a facet angle Conclusion: Our data show that ILP is a safe and effective procedure in the treatment of grade I degenerative spondylolisthesis.