Posterolateral, Anterior or Circumferential Fusion In Situ for High-Grade Spondylolisthesis in Young Patients: A Long-term Evaluation Using Scoliosis Research Society Questionnaire

Summary: Circumferential non-instrumented fusion provided significantly better Scoliosis Research Society questionnaire and Oswestry Disability scores at long-term follow-up and prevented progression of the sagittal deformity better than posterolateral or anterior non-instrumented fusion in the treatment of high-grade pediatric spondylolisthesis.

Introduction: Controversial opinions still exist about the surgical treatment of severe isthmic spondylolisthesis. There are no long-term comparative studies of different fusion in situ techniques in young patients.

Objective: To compare clinical and radiographic outcomes after posterolateral, anterior or circumferential fusion in situ for high-grade spondylolisthesis in children and adolescents.

Materials and Methods: Twenty-one patients treated using posterolateral, twenty-three using anterior, and twenty-six using circumferential fusion in situ technique without instrumentation for highgrade isthmic spondylolisthesis (>50% slip) participated in this study. None of them underwent nerve decompression at the primary operation. The follow-up rate was 84% after a mean of 17.2 (range, 10.7 to 26.0) years. Radiographs were obtained preoperatively, at 2-year follow-up, and at final follow-up. The SRS and Oswestry Disability Index (ODI) questionnaires were completed and a physical examination performed at the final follow-up visit.

Results: Non-union after primary operation was found in three (14%) patients after posterolateral and in one (4%) patient after circumferential fusion. Progression of the slip (>10 per cent points) was noted in four (19%), one (4%), and three (12%) patients of the posterolateral, anterior and circumferential fusion groups, respectively (NS.). Progression of the lumbosacral kyphosis (>10 degrees) was found in nine (43%), three (13%), and three (12%) patients of the posterolateral, anterior and circumferential fusion groups, respectively (p=0.017). Circumferential fusion provided significantly better SRS total score and ODI than anterior or posterolateral fusion (p=0.021 and p=0.035). There was a significant correlation between SRS total score and ODI (rs = -0.65, 95% CI -0.77 to -0.48, p <0 .0001). The percentage slip showed inverse correlations with SRS scores for general and postoperative self-image domains.

Conclusions: Circumferential fusion seems to be the treatment of choice for pediatric high-grade isthmic spondylolisthesis if instrumentation is not used. SRS questionnaire can be used as a primary patient-oriented outcome tool after surgery for spondylolisthesis in young patients.