Long-Term Experience With Reduction Technique in High-Grade Spondylolisthesis in the Young

Abstract

Background: Surgical management of high-grade spondylolisthesis in the young is not only challenging but also controversial, from in-situ fusion to complete reduction. It is fraught with dangers such as neurological injury, pseudoarthrosis, and progressive deformity with subsequent global sagittal imbalance. We describe our experience of progressive reduction technique and restoration of lumbosacral alignment.

Methods: This study is a retrospective review of patients who underwent surgery between 1998 and 2012. The surgical technique involved positioning the hips in extension with traction, pedicle screw fixation, correction of lumbosacral kyphosis with a specific distraction maneuver, wide decompression, and gradual reduction of the deformity and maintenance of reduction with interbody fusion. All patients were serially assessed at 1, 3, and 6 months and yearly thereafter with clinical, radiological, and Oswestry Disability Index and Visual Analogue Scale outcome measures.

Results: Twenty-seven patients with high-grade spondylolisthesis at L5-S1 (3 cases grade 3, 7 grade 4, 17 grade 5) with an average age of 13.9 years were reviewed. Mean follow-up was 120 months (range 24-192). All patients presented a solid fusion at the 6-month visit; mean slip percentage was reduced from 89% to 23%, with all cases reduced to grade 2 or less. The slip angle improved from 45° to 3° postoperatively, with improvement in sacral slope from 13° to 35°. Four spondyloptosis patients had concomitant scoliosis which corrected spontaneously after the surgery and did not need further intervention. All but one patient (96.2%) had good functional outcomes and returned to their full normal activities. One patient developed a deep infection necessitating implant removal, with eventual deformity progression leading to a poor outcome. Three patients (11.1%) suffered partial drop foot that resolved in full by 12 weeks.

Conclusion: Our technique demonstrated a significant reduction of high grade spondylolisthesis, with restoration of global sagittal balance via correction of the lumbosacral kyphosis. Though surgically demanding, it is safe and reproducible.

Level of evidence: IV.

Keywords: high-grade spondylolisthesis; instrumentation; lumbosacral kyphosis; reduction; sagittal balance.

Figures 1 and 2

Correction of lumbosacral kyphosis is initiated by distraction using a cantilever mechanism between L2-3 screws and sacrum.

Figure 3

Distraction of the screws allows entry and insertion of pedicle screw into L5.

Figure 4

Sacral dome excision using an osteotome after L5 screw placement.

Figures 5 and 6

Figure 5. Reduction of listhesis through L5 reduction screws or use of reducers to bring the screw to the rod. Figure 6. L5/S1 interbody space distraction to further reduce the lumbosacral kyphosis.

Figures 7 and 8

Removal of temporary L2-3 screws and rod followed by compression of L5/S1 over an interbody device to give final construct which shows restored sagittal balance.

Figure 9

Image shows final construct with good reduction (spondyloptosis to grade I) and interbody fusion.

Figures 10–12

A case of 8-year-old girl with grade 4 spondylolisthesis who refused surgery, had slip progression in 4 years, and then underwent reduction and fusion. This is an example of our earliest case where fixation was extended to L4 and a Chopin plate system was used at the sacrum.

Figures 13 and 14

Eleven-year follow-up shows implants in good position, with no loss of reduction and maintenance of normal radiographic parameters.

Figures 15 and 16

A case example of a 10-year-old girl with spondyloptosis who underwent the reduction technique and posterior fusion.

Figures 17 and 18

Two-year follow-up images showing no loss of reduction with stable pelvic parameters. Concomitant scoliosis also corrected spontaneously by surgery.

Figure 19

Images of one patient with deep infection which occurred in late postoperative period necessitating implant removal. The patient had further deformity progression at her last follow-up.