“The protective buffer”: Adequate L4-S1 lordosis restoration reduces the symptomatic conversion of radiographic ASD and long-term revision rates — A 5-year multicentre cohort study
European Spine Journal · 30 Jul 2026
† Impact is the editorial-priority score. All scores are out of 100. Clinical is a stored clinical-importance score from the earlier method; it has not been recalculated.
Why it matters
It suggests that getting L4-S1 lordosis into a specific numeric target at the index TLIF may be one of the biggest levers surgeons have to prevent costly, disabling revision surgery down the road.
The evidence
This retrospective, three-centre cohort followed 232 patients who had L4-S1 TLIF for degenerative lumbar disease, comparing those whose surgeons restored 'adequate' segmental lordosis (35-45 degrees) versus those who did not, over a minimum of 5 years. Patients with inadequate lordosis restoration had much higher rates of pelvic retroversion, symptomatic adjacent segment disease, implant failure, and reoperation (26.4% revision vs 2.4% in the adequate group, P<0.001), along with worse pain and disability scores at final follow-up.
5-year revision surgery rate: Risk difference 24 (95% CI unavailable; units not reported).
Why this rigour score?
Retrospective cohort
Methods at a glance
Recorded assessment- Confounding adjustmentMultivariable regression
- Covariate balance confirmedNot reported
- Outcome assessors blindedMet
- Comparable start of follow-upMet
- Adequate statistical powerCalculation absent
- Prospective registrationNot met
Not reported does not mean not done. Checks have different weights; this is not a count of boxes ticked.
How to read this assessment
The recorded methods are shown alongside the published score. A verified point-by-point calculation is not available for this version of the appraisal.
Checklist from the stored appraisal. “Not met” describes the recorded criterion; it does not always produce a deduction. This overview supports reading the full study.
For journal club
1.If a 35-45 degree L4-S1 lordosis target were adopted as a routine intraoperative checkpoint, how should surgeons balance achieving it against added operative time, blood loss, or neural risk from more aggressive releases?
2.For patients in whom anatomic constraints (rigid facets, sclerotic endplates) prevent reaching this lordosis target with TLIF, should surgeons instead default to an anterior approach (ALIF/OLIF) to achieve better sagittal correction?
Original publication title
“The protective buffer”: Adequate L4-S1 lordosis restoration reduces the symptomatic conversion of radiographic ASD and long-term revision rates — A 5-year multicenter cohort study