Application of extracorporeal collagenase chemonucleolysis and combined intradiscal and extracorporeal collagenase chemonucleolysis via FLEX electrode in patients with lumbar disc herniation: a retrospective study.

Objective: This study aimed to investigate and compare the short-term and long-term clinical outcomes of extracorporeal collagenase chemonucleolysis(ECCNL) and intradiscal-extracorporeal collagenase chemonucleolysis(IECCNL) via FLEX electrode in patients with lumbar disc herniation (LDH).

Method: A retrospective analysis was performed on 65 patients diagnosed with LDH who met the inclusion criteria between April 2021 and April 2022. Patients were divided into two groups: 30 received ECCNL via FLEX electrodes (Group A) and 35 received IECCNL via FLEX electrode (Group B). Clinical outcomes were evaluated using the modified MacNab criteria, Numerical Rating Scale (NRS), and Japanese Orthopaedic Association (JOA) scores to assess the excellent/good rate, excellent rate, pain severity, and neurological function at specified intervals (3, 6, 12, and 24 months for clinical outcomes; 3 days, 1, 3, 6, 12, and 24 months for pain/neurological status). Perioperative complications, recurrence rates, and reoperation rates were systematically documented.

Results: A total of 58 patients were included. At 1 month postoperatively, Group A showed significantly lower NRS scores compared to Group B (P < 0.05) and a higher pain relief rate (P < 0.05). Although Group A had higher JOA scores than Group B at 3 days postoperatively (P < 0.05), Group B showed higher JOA scores than Group A at 24 months postoperatively (P < 0.05). The excellent-good rate between the two groups at any postoperative time point, Group B demonstrated a significantly higher excellent rate than Group A at both 3 months and 24 months postoperatively (P < 0.05). In Group A, there was 1 case of recurrence and 2 reoperations, with a recurrence rate of 3.45% [95% CI: 0.09%, 17.7%] and reoperation rate of 6.90% [95% CI: 0.84%, 22.8%]. Group B showed no recurrences or reoperations [95% CI: 0%, 9.7%] for both outcomes. No statistically significant differences were observed between the two groups. During the 24-month follow-up period, no severe complications were observed in Group A. However, one case of nerve root injury occurred in Group B.

Conclusion: FLEX electrode application in conjunction with two collagenase injection strategies enhances therapeutic outcomes. Short-term results favor ECCNL alone, whereas long-term benefits are more pronounced with the intradiscal-extracorporeal therapy.