Minimally invasive subtalar arthroereisis versus lateral column lengthening for symptomatic pediatric idiopathic flatfoot: a systematic review and meta-analysis of patient-reported outcomes and re-operation rates

Symptomatic paediatric idiopathic flexible flatfoot that fails supervised non-operative care may be treated by lateral column lengthening (LCL) or by minimally invasive subtalar arthroereisis (AR). The comparative evidence base has consisted largely of indirect comparisons between separate single-arm cohorts. This systematic review and meta-analysis synthesised only direct head-to-head evidence on foot-specific functional outcome measures and on re-operation. PubMed, Embase, the Cochrane Library, Web of Science and Scopus were searched from database inception to 30 June 2026 for comparative studies of AR versus LCL in children aged 18 years or younger with symptomatic idiopathic flexible flatfoot. Foot-specific functional outcome measures, comprising the patient-reported Oxford Ankle-Foot Questionnaire (OAFQ) and the clinician-administered American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, were pooled as standardised mean differences (SMD, Hedges’ g) in a random-effects model using restricted maximum likelihood estimation with Hartung-Knapp small-sample inference. Because re-operations were rare, the Peto odds ratio (OR) was the primary effect measure, with Mantel-Haenszel risk ratio (RR) and risk difference as sensitivity analyses and no continuity correction applied. An additional analysis adjusted for the clustering of bilateral feet within patients. Risk of bias and certainty of evidence (GRADE) were assessed. Five studies (397 feet) were included. Three studies (333 feet; 112 AR, 221 LCL) contributed to the functional outcome meta-analysis and four (357 feet; 125 AR, 232 LCL) to the re-operation meta-analysis. The pooled SMD (AR minus LCL) was − 0.07 (95% confidence interval [CI] − 0.61 to 0.47; P = 0.63) with no detectable heterogeneity (I 2 = 0%). Eight re-operations occurred across 357 feet. The pooled Peto OR for re-operation after AR versus LCL was 2.55 (95% CI 0.58 to 11.22; P = 0.22; I 2 = 0%); the Mantel-Haenszel RR was 2.54 (95% CI 0.55 to 11.62) and the risk difference 2.1% (95% CI − 1.3 to 5.6%). Cluster-adjusted and leave-one-out analyses did not alter these findings. Certainty of evidence was low for functional outcome and very low for re-operation. Direct comparative evidence does not demonstrate a difference in foot-specific functional outcome between minimally invasive subtalar arthroereisis and lateral column lengthening. The evidence is, however, too imprecise to establish equivalence, and the confidence intervals remain compatible with a clinically important advantage for either procedure. Unplanned re-operation is uncommon after both operations, but once the planned removal of non-absorbable sinus tarsi implants is taken into account the total reintervention burden of arthroereisis is considerably greater. Procedure choice should currently be individualised, and an adequately powered non-inferiority trial is required.