Discectomy after Chemonucleolysis with Condoliase for Lumbar Disc Herniation

Abstract

Introduction: There are scattered reports on the efficacy of intradiscal condoliase injection therapy for lumbar disc herniation. However, there are few reports focused on discectomy after condoliase. In this study, we examined the characteristics of patients who underwent discectomy after condoliase injection.

Methods: The study included 200 consecutive patients (127 men and 73 women) who received intravertebral condoliase injection therapy from December 2018 to July 2023. The mean age was 46.2 years (15-89). The time from onset to injection was 25.7±32.2 weeks, and tension sign before injection was positive in 146 patients (73%). We investigated the visual analog scale scores for low back and leg pain, and the Oswestry Disability Index as clinical assessments. The conversion to discectomy and the timing of the conversion were investigated. Imaging evaluation included herniation size transition and progressive disc degeneration using before and one month after injection magnetic resonance imaging (MRI), and the presence of type 2 (T2) high-signal areas within the herniation on pre-injection MRI.

Results: The mean visual analog scale score for low back pain improved significantly from 5.4 cm pre-injection to 3.4 cm post-injection, and that of leg pain improved significantly from 7.0 to 3.7 cm. The Oswestry Disability Index also improved significantly from 42.4% to 26.8%. Herniation size decreased from 56.8 mm² pre-injection to 43.5 mm² post-injection. Disc degeneration was mildly progressed in 109 patients (56.2%). T2 high-signal areas were present in 111 patients (55.5%). Discectomy after condoliase was performed in 16 patients (8%) at 11.5±10.7 weeks after injection. The conversion group was older than other groups (57.3±16.5 vs. 45.3±17.7 years, p = 0.014), had a lower rate of positive tension signs (50% vs. 75%, p = 0.031), and was more likely to have no T2 high-signal area in the herniation on pre-injection MRI (25% vs. 58.2%, p = 0.011).

Conclusions: Discectomy after condoliase was performed in 8% of patients, with a mean time of 11.5 weeks after injection. The characteristics of conversion to discectomy were older age, negative tension signs, and lack of T2 high signal in the herniation on MRI.