Does pretreatment Pfirrmann grade modify response to intradiscal condoliase injection for lumbar disc herniation?

Condoliase is an intradiscal chemonucleolytic agent for lumbar disc herniation, but its effectiveness may depend on disc degeneration severity. We evaluated whether pretreatment Pfirrmann grade is associated with outcomes after intradiscal condoliase injection.

We retrospectively analyzed patients treated with intradiscal condoliase at nine institutions in Japan (2018-2021). Pretreatment disc degeneration was graded using the Pfirrmann system. Back and leg pain were assessed using the Numerical Rating Scale (0-10) at baseline, 3-6 months, and 1 year. Clinically meaningful response was defined as at least 50% improvement from baseline. Associations across Pfirrmann grades Ⅱ-Ⅳ were tested as an ordinal trend and using multivariable models adjusted for age, sex, injected level, and symptom duration. Early post-treatment Pfirrmann grade change and reintervention surgery within 1 year were also assessed.

Among 202 patients (Pfirrmann grade Ⅱ, 7 patients; grade Ⅲ, 107; grade Ⅳ, 84; grade Ⅴ, 4), leg pain improved overall. Graded differences were not evident at 3-6 months, but higher pretreatment Pfirrmann grade was associated with higher residual leg pain at 1 year (P for trend <0.001) and lower leg pain responder rates (100%, 88.4%, and 69.2% for grades II, III, and IV; adjusted P for trend = 0.005). Adjusted mean change scores did not show a statistically significant ordinal trend. Early post-treatment Pfirrmann grade progression was not associated with worse 1-year outcomes. Reintervention surgery was more frequent in grade Ⅳ than in grade Ⅲ (16.7% and 4.7%, respectively).

More advanced pretreatment disc degeneration was associated with a lower likelihood of achieving substantial leg pain improvement at 1 year after intradiscal condoliase injection. Pretreatment Pfirrmann grade may be useful for patient counseling and treatment selection.