Indication and Limitation of Intradiscal Condoliase Injection for Patients with Lumbar Disc Herniation: Literature Review and Meta-Analysis.

Background: Intradiscal condoliase injection for lumbar disc herniation (LDH) was developed in Japan in 2018. The treatment is intermediate between conservative therapy and surgery, and its frequency is increasing. Condoliase is limited to a single application over a lifetime, rendering it important to understand the indications and predictors of its effectiveness. This review aimed to summarize published studies and provide appropriate indications and limitations for appropriate patient selection based on existing findings. Methods: While adhering to PRISMA guidelines, we searched the PubMed, Web of Science, and EMBASE databases to identify articles reporting the clinical outcomes of intradiscal condoliase injection for LDH. Data extraction focused on the effective rate, prognostic factors, and posttreatment imaging changes and was used in the meta-analysis. Results: Nineteen studies met the inclusion criteria. Our meta-analysis revealed 78% total response, 11% posttreatment surgery, and 42% posttreatment Pfirrmann-classification-grade progression rates. Posttreatment intervertebral disc degeneration was potentially associated with an improved response rate and disc regeneration one year posttreatment, especially in young patients. The Regimen for patients aged <20 and >70 years should be carefully selected, including those with a disease duration of >1 year, recurrent LDH, small-sized LDH, vertebral instability, and inadequate duration (<3 months) of conservative therapy. Conclusions: Although long-term outcomes and imaging changes must be evaluated owing to the heterogeneity of previous studies, intradiscal condoliase injection is a minimally invasive and cost-effective treatment option for patients with LDH. Treatment indications should be determined after carefully evaluating evidence from previous conservative and surgical treatments.