Spine Journal - 2026-08-01 - Journal Article; Multicenter Study; Comparative Study
Transforaminal endoscopic lumbar discectomy versus interlaminar endoscopic lumbar discectomy for lumbar disc herniations: a prospective multicenter study of recovery trajectories using high-frequency patient-reported outcome measures.
Krause PK, Leyendecker J, Payne C, Tran NT, Teilfeian A, Derman PB, Ogunlade J, Hasan S, Konakondla S, Huang M, Gardocki RJ, Mahan M, Khan I, Amin A, Bredow J, Hofstetter CP, Endoscopic Spine Research Group (ESRG)
Topics
Key Takeaway
IELD produced greater short-term functional improvement over TELD at 6 months (ODI difference -6.14 points, p<0.001), but differences converged by 12 months, with surgical approach accounting for only 2–3% of outcome variance.
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Summary
This prospective multicenter study compared recovery trajectories after TELD versus IELD using high-frequency PROMs collected daily in week 1 and at fixed intervals through 12 months. IELD showed faster early recovery with adjusted ODI differences peaking at -6.14 points at 6 months (p<0.001), but trajectories converged by 12 months. BMI (η²=0.06) and disc morphology (η²=0.04) were stronger outcome predictors than surgical approach (η²=0.02–0.03).
Key Limitation
Non-randomized design with systematic case allocation by pathology type (foraminal herniation preferentially treated with TELD, L5-S1 central/paracentral with IELD) confounds the between-group comparison despite multivariable adjustment.
Original Abstract
BACKGROUND CONTEXT
Full-endoscopic lumbar discectomy can be performed via transforaminal (TELD) or interlaminar (IELD) routes, yet comparative evidence on early recovery trajectories remains limited.
PURPOSE
To evaluate postoperative pain and disability patterns after TELD and IELD and identify approach-specific recovery characteristics and predictors.
STUDY DESIGN/SETTING
Prospective multicenter cohort study.
PATIENT SAMPLE
A total of 573 patients undergoing ambulatory full-endoscopic lumbar discectomy (351 TELD, 222 IELD).
OUTCOME MEASURES
VAS back pain, ipsilateral leg pain, and Oswestry Disability Index (ODI).
METHODS
Patient-reported outcomes were collected via the SpineHealthie platform daily during week 1 and at 2 weeks, 1, 3, 6, and 12 months. Linear mixed-effects ANCOVA models adjusted for baseline patient-reported outcome measures, age, body mass index, disc morphology, and L5/S1-level were used to compare trajectories.
RESULTS
Both techniques yielded rapid, durable reductions in pain and disability. IELD demonstrated faster and more pronounced early recovery. Adjusted mean differences favored IELD at 2 weeks for back pain (-0.77; p=.014) and ODI (-2.50; p=.042), peaking at 6 months (back pain -1.27; ODI -6.14; both p<.001). Differences converged by 12 months for ODI. Surgical approach accounted for 2%-3% of variance (η²=0.02-0.03), while disc morphology (η²=0.04) and body mass index (η²=0.06) emerged as independent predictors. Age had no effect.
CONCLUSIONS
TELD and IELD are safe, effective techniques. IELD enables faster recovery and greater short-term functional improvement, whereas TELD provides durable long-term benefit, especially for foraminal and upper lumbar pathology. Outcomes depend on surgical exposure, disc morphology, and body habitus, supporting an anatomy-guided, individualized approach.