Concomitant low-grade isthmic L5-spondylolisthesis does not affect the course of adolescent idiopathic scoliosis

Abstract

Background: Scoliosis with spondylolisthesis was described in 4.4–48%. No information on clinical impact or outcome is available. Purpose: To determine the prevalence of this pathology and to investigate its affect on the course of adolescent idiopathic scoliosis (AIS). Methods: A retrospective comparative study using patients’ records, radiographs, the national inpatient registry, and Patient-rated outcome measures (PROM): Oswestry disability index (ODI), modif.SRS-24 questionnaire, WHO-Quality of life index (WHOQoL), Numerical rating scale (NRS) for pain. Clinical follow-up time was 4.4 (4.3) years, and follow-up rate was 95%. PROM follow-up time 26.4 (2.8) years χ2 statistics and t-tests were applied. Significance threshold was set at P < 0.05. Results: Out of 1531 consecutive Caucasian AIS patients, aged 13.9 (1.8) years, primary curve 29.2 (11.5) drs., 120 (7.8%) had low-grade isthmic L5-slip of mean 15.0 (8.3)% (Study group = S). The distribution of the curve types in the study group was comparable to the remaining 1411 patients with AIS only. In comparison with a pair-matched control group (C) at admission, back pain interfering with activities of daily living had 4.2% of the study group and 1.7% of the control group, at clinical follow-up 2.6/4.2% resp. (n.s.). Between groups S/C, there was no significant difference concerning scoliosis treatment: observation 38.3/45.8%, bracing 48.3/46.6%, surgery 10.8/10.2%. Results of treatment were equal in both groups. Long-term outcomes (ODI, SRS-24, WHOQoL, NRS-back/leg pain) were comparable. Conclusions: The prevalence of low-grade isthmic L5-spondylolisthesis in AIS patients was 7.8%. The presence of low-grade isthmic spondylolisthesis did not influence the curve type of AIS nor did it affect the course or long-term outcome. Graphic abstract: These slides can be retrieved under Electronic Supplementary Material. [Figure not available: see fulltext.].