A new three-stage spinal shortening procedure for reduction of severe adolescent isthmic spondylolisthesis: a case series with medium- to long-term follow-up.

Study Design: A case series of eight consecutive patients with severe (Meyerding Grade ≥ 3) adolescent isthmic spondylolisthesis (SAIS) who underwent reduction and stabilization by using a new surgical technique.

Objective: To report the results of a safe three-stage spinal shortening procedure in a single operative session in eight patients with SAIS.

Summary Of Background Data: The treatment of SAIS is controversial and the opinion continues to remain divided between in situ fusion and reduction followed by stabilization. We reported a new surgical technique to facilitate safe reduction and stabilization of SAIS and the results in eight adolescents are presented.

Methods: Eight patients with Meyerding Grade III (2), IV (5), and V(1) were operated between 2000 and 2006 for SAIS. The back/leg pain duration was 13.7 months and average age at surgery was 14.75 years. The slip angle (SA), percentage slip (%S), sacral inclination (SI), lumbar lordosis (LL), pelvic incidence (PI), and sagittal balance were measured and the Oswestry Disability Index (ODI) and visual analog scale pain score were used as outcome measures. All patients underwent posterior decompression with sacral dome osteotomy, anterior transperitoneal L5/S1 discectomy, and posterior reduction and instrumented circumferential fusion in a single operative session.

Results: The average follow-up was 6 years. The mean preoperative degree of slip was 86%, which improved to 5% (r 1-17%, spondyloptosis case 32%) postoperatively. The mean L5 SA, SI, and LL preoperatively were 48°, 34°, and -72°, respectively, and postoperatively improved to 43° and -47°, respectively. The sagittal balance was 55 and 34 mm pre- and postoperatively, respectively. Near anatomical reduction was achieved in seven patients. No implant failures or revisions to date. The mean ODI improved to 6% from 56% and visual analog scale from 8 to 1, postoperatively.

Conclusion: This safe 3-stage procedure assists sudden reduction and circumferential fusion of SAIS without any neurologic deficit and excellent clinicoradiologic outcome restoring normal lumbosacral biomechanics.