Poster Presentation 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

Introduction. Modic changes are dynamic subchondral bone marrow changes which can be identified on magnetic resonance imaging (MRI). In particular, type1 change is associated with activation of inflammation in the intervertebral disc (IVD) and severe low back pain (LBP).¹ Since recent studies demonstrated Modic changes as infection by low virulent anaerobic bacteria,² we developed full-endoscopic disc cleaning (FEDC)³ surgery to ameliorate patients’ inflammation and symptom. The aim of this study is to clarify the clinical short-term outcomes of FEDC surgery against intractable LBP with Modic type1 change, and to identify the possible predictive factors for good outcomes.

Methods. We retrospectively reviewed patients who underwent FEDC surgery from 2019 to 2023 due to discogenic LBP with Modic type1 refractory to conservative care including medications (intravenous/oral administration of corticosteroids and/or antibiotics), and rehabilitation. The diagnosis of discogenic pain was confirmed by temporal pain reduction after discography of IVD with Modic type1 change with local anesthetic agents. FEDC surgery was performed via transforaminal approach under local anesthesia. We performed cleaning inside the IVD with much saline, ablation of abnormal bleeding from angiogenesis with radiofrequency, and debridement of abnormal structures such as inflammatory scar. Visual analog scale (VAS) value at surgery, one month postoperatively, and final follow-up were used to evaluate clinical outcomes. We defined the good outcome as the cases whose VAS value decreased to 50% or less of preoperative value at final follow-up. Age, sex, body mass index (BMI), lesion level, duration of LBP, lumbar lordosis angle, and Cobb angle were also collected at surgery. The mean VAS value between baseline and timepoints after surgery was compared using the Student t-test. Possible predictive factors for the good outcome were compared using the Student t-test and the Chi-square test between patients with and without good outcomes. Statistical significance was set at a P value <0.05.

Results. Consequently, 26 patients (male, n=19; female, n=7) with 31 IVD levels were included. The mean age was 53.2±15.0 years. The most of the patients (74.1%) was associated with lower lumbar IVDs (L4–5/L5–S1). No perioperative complications were observed. Two (7.7%) patients had additional surgery (fusion surgery) due to poor improvement or recurrence. The mean follow-up duration was 13.6 months (range, 6 to 24 months). The mean VAS values significantly decreased from 6.5±1.7 cm at surgery to 3.3±2.5 cm at one month postoperatively and 3.7±1.1 cm at final follow-up (both, P<0.05). Fourteen (53.8%) patients showed good outcomes. Representative cases with chronological MRI and VAS values are shown in Figure. Younger age, no co-existence of Modic type3 change, and the presence of concordance LBP during discography were associated with the good outcome (all, P<0.05) (Table).

DISCUSSION.

Although the pathophysiological mechanisms still remain elusive, Modic changes are associated with poor clinical and functional outcomes after both conservative and surgical treatment.² FEDC is a new less invasive and effective surgery against Modic type 1-related discogenic LBP. Patients with younger age, no co-existence of Modic type 3change, and the presence of concordance LBP during discography might be good indications for FEDC.