Replacement of Vertebral Lamina (Laminoplasty) in Surgery for Lumbar Isthmic Spondylolisthesis: 5-Year Follow-Up Results

Abstract

Study design: A review of clinical and radiological outcomes of lumbar laminoplasty (LL) for the treatment of isthmic spondylolisthesis (ISL).

Purpose: The single session performance of posterior lumbar interbody fusion with allograft in the anterior column and providing the realignment of the vertebrae was presented as a preliminary report earlier.

Overview of literature: Long-term surgical outcome of cervical laminoplasty in patients has been reported. But, outcome of LL in patients is unclear.

Methods: The long-term (5 years) year follow-up results of the LL technique are reported in this retrospective study. All patients underwent preoperative and postoperative direct X-ray, computed tomography, and magnetic resonance imaging. The patients that did not respond to conservative treatment were operated. Twenty-one (52.5%) female and 19 (47.5%) male patients were included.

Results: Mean age was 43,5 years (ranges, 22-57 years). The most common symptoms were low back pain (89%), pelvic and leg pain (69%) and reduction in walking distance (65%). A total of 180 pedicle screws were inserted in 40 patients; posterior lumbar interbody fusion and laminoplasty with reduction was performed in 20 patients for L4-L5, 12 patients for L5-S1, 4 patients for L3-L4-L5 and 4 patients for L4-L5-S1. Ten (25%) patients with ILL had accompanying spinal stenosis. The difference between preoperative and postoperative sagittal plane rotation and dislocation degrees and disc space heights were statistically significant in all patients (p<0.05). Solid grade 4 fusion was observed in 38 patients; in only 2 patients grade 2 pseudoarthrosis developed (5%), but these patients were asymptomatic. Visual analog scale, Prolo economical and functional scale was examined with an average follow-up 5.5 years.

Conclusions: LL technique has the advantages of shorter duration of operation, lack of graft donor site complications, protection of posterior column osseoligamentous structures and achievement of high fusion rates in one session.

Keywords: Follow up studies; Isthmic spondylolisthesis; Laminoplasty; Long term; Lumbar; Posterior fusion.

Fig. 1. Lateral X-ray shows the lysthetic segment at L4–L5 level.

Fig. 2. Lateral (sagittal) lumbar vertebral computed tomography scan reveals the lysthetic segment at L4–L5 level.

Fig. 3. The laminae after en-bloc resection.

Fig. 4. Allograft insertion to the intervertebral space.

Fig. 5. Lateral (sagittal) lumbar vertebral computed tomography scan at 6 months postoperatively. Achievement of the restorative sagittal balance after the insertion of the allograft and compression of the level.

Fig. 6. The laminae 3 months after replacement viewed in an axial lumbar vertebral computed tomography scan.

Fig. 7. Fusion of the laminae is visible at 5 years in an axial lumbar vertebral computed tomography scan.