Predictive factors for outcomes of chemonucleolysis with condoliase in lumbar disc herniation: A multi-institutional study

Background: Chemonucleolysis with condoliase is a minimally invasive treatment for lumbar disc herniation (LDH). However, optimal patient selection criteria remain unclear. This study aimed to identify predictive factors for successful condoliase therapy in LDH, focusing on low back pain (LBP) and leg pain improvement. Methods: This multi-institutional observational study included 238 patients who underwent intradiscal condoliase injection for LDH. Demographic and clinical data were collected, including pain intensity using the Numeric Rating Scale (NRS) for leg and back pain at baseline, 3–6 months, and 12 months. MRI assessments evaluated disc height, Pfirrmann grade, and herniation occupancy ratio. The primary outcome was defined as achieving the minimum clinically important difference (MCID) on the 0–10 NRS, defined as an improvement of ≥2 points at 3–6 months or 12 months, without additional surgery during follow-up. Multivariable logistic regression was used to identify predictors of MCID achievement. Results: Condoliase was effective, with over 70 % of patients achieving MCID for leg pain and over 50 % for LBP. For LBP at 3–6 months, higher baseline back pain intensity (OR 3.09, 95 % CI 2.00–4.78), lower MRI slip (OR 0.59, 95 % CI 0.38–0.92), higher MRI occupancy rate (OR 1.74, 95 % CI 1.19–2.54), and L5/S1 injection level (OR 2.20, 95 % CI 1.06–4.54) predicted MCID achievement. At 12 months, higher baseline back pain intensity (OR 2.26, 95 % CI 1.49–3.44), higher MRI occupancy rate (OR 1.85, 95 % CI 1.24–2.79), shorter disease duration (OR 0.57, 95 % CI 0.38–0.86), and absence of X-ray posterior slip (presence: OR 0.18, 95 % CI 0.04–0.91) were associated with MCID achievement. For leg pain at 3–6 months, lower MRI slip (OR 0.60, 95 % CI 0.41–0.89) and higher baseline leg pain intensity (OR 1.72, 95 % CI 1.23–2.41) were associated with MCID achievement. For leg pain at 12 months, shorter disease duration (OR 0.61, 95 % CI 0.42–0.88), lower X-ray slip (OR 0.54, 95 % CI 0.30–0.97), higher baseline leg pain intensity (OR 1.94, 95 % CI 1.30–2.88), and lower Pfirrmann grade (OR 0.48, 95 % CI 0.23–0.99) were predictive of MCID achievement. Conclusions: This study identified key factors associated with successful outcomes of condoliase in LDH. Baseline pain intensity, MRI findings (herniation occupancy rate, slip), injection level, and disease duration were significant predictors of treatment outcomes. These findings may aid clinicians in patient selection and improve treatment success.