Understanding the Natural Course of Degenerative Lumbar Scoliosis: Insights from a Systematic Review and Meta-analysis

Introduction: The optimal treatment algorithm for degenerative lumbar scoliosis (DLS) remains unclear, partly due to limited studies on its natural history. Understanding this is essential for surgical decision-making. We aimed to determine the proportion of patients developing de novo DLS, the progression of preexisting DLS, and the rate of progression.

Methods: A systematic search of Ovid, EMBASE, and the Cochrane Library (through January 2024) followed PRISMA guidelines (PROSPERO: CRD42024502853). Keywords such as “lumbar scoliosis,” “degenerative scoliosis,” and “conservative treatment” were used. Studies with over ten non-surgical DLS patients managed conservatively were included. Extracted data included demographics, scoliosis severity, progression rates, and clinical outcomes. Study quality was assessed using the Newcastle-Ottawa Scale (NOS) and Joanna Briggs Institute (JBI) Checklist. A random-effects model was used to pool the results. All analyses were performed using R Studio.

Results: Of the 2456 studies identified, we included 12 (1982-2021) with 2,287 patients, followed for 2-18 years. The cohort was 70% female, aged 58-79 years on average. Six studies (1,215 patients) reported a pooled de novo DLS incidence of 27% (95% CI: 17%-42%, I² = 88%) over 5-15 years. Ten studies (1,609 patients) showed a 40% pooled progression rate (95% CI: 20%-65%, I² = 81%) for preexisting DLS, with an average annual progression of 1.16° (95% CI: 0.15°-2.17°, I² = 99%). Clinical outcomes were inconsistently reported. Most studies were rated high or moderate quality using the NOS and JBI tools.

Conclusion : This study revealed a 27% de novo DLS incidence and a 40% progression rate for preexisting DLS. These findings are crucial for patient counseling and surgical decision-making. However, substantial heterogeneity was observed across studies, suggesting significant variability in factors influencing DLS development and progression. Further research is needed to identify these factors and reduce uncertainty in clinical management, ultimately improving treatment strategies for DLS.