Disc Level-Specific outcomes of intradiscal condoliase injection for lumbar disc herniation: A multicenter retrospective study.

BACKGROUND

The efficacy of intradiscal condoliase injection for lumbar disc herniation (LDH) may vary depending on the affected disc level. This is especially relevant in upper lumbar herniations, where anatomical constraints can complicate surgical treatment. Although condoliase has emerged as a less invasive option, disc-level-specific outcomes remain underexplored.

METHODS

This multicenter retrospective cohort study included 262 patients with LDH who underwent either intradiscal condoliase injection (CD group, n = 207) or microendoscopic discectomy (MED group, n = 55). Patients were categorized by herniation level: upper lumbar (L1/2, L2/3, L3/4) and lower lumbar (L4/5, L5/S1). The primary objective was to examine whether the effectiveness of condoliase differs by disc level. MED outcomes were included for reference. Primary outcomes included improvement in numerical rating scale (NRS) scores for leg and back pain at 1 year, responder rate (≥50 % improvement in leg pain), and reoperation rate. Intermediate-term (3-6 month) NRS data were also analyzed in a subset.

RESULTS

Condoliase demonstrated consistent efficacy across disc levels, with particularly favorable outcomes at upper lumbar levels. At L1/2-L3/4, the CD group achieved a 100 % responder rate and the greatest mean improvement in leg pain (6.9 ± 2.4). At L3/4, outcomes in the CD group were superior to those in the MED group (100 % vs. 57.1 % responder rate). At L4/5, while condoliase was effective, reference data from the MED group showed greater leg pain relief (7.2 ± 2.5 vs. 5.0 ± 2.8) and a higher responder rate (100 % vs. 81.2 %). At L5/S1, both treatments produced similar results. Improvements in low back pain were modest and comparable across levels and groups. In the subset analysis, MED showed faster early symptom relief at L4/5, but condoliase provided steady improvement over time.

CONCLUSION

The effectiveness of condoliase injection therapy differs by disc level and appears particularly favorable at upper lumbar levels. Condoliase represents a safe, minimally invasive alternative for treating upper lumbar LDH. These findings support disc-level-based treatment selection when choosing between condoliase and surgical intervention.