Outcomes of subtalar arthroereisis for pediatric and adolescent flexible flatfoot: A systematic review comparing metallic versus bioabsorbable implants.

BACKGROUND

Subtalar arthroereisis is widely used to treat flexible flatfoot in growing patients. Metallic implants have historically been standard, whereas bioabsorbable devices have emerged as an alternative that may reduce implant-related symptoms and avoid elective hardware removal. We systematically compared clinical and radiographic outcomes, complication rates, and patient-reported satisfaction between metallic and bioabsorbable implants.

METHODS

We performed a PRISMA-compliant systematic review and meta-analysis. PubMed, Embase, the Cochrane Library, and Web of Science were searched to December 2024. We included clinical studies of subtalar arthroereisis using metallic and/or bioabsorbable implants in pediatric and adolescent flexible flatfoot. Primary outcomes were complication rates (complications, non-routine implant removal, persistent sinus tarsi pain), radiographic parameters, and patient-reported outcomes. Two reviewers independently screened studies, extracted data, and assessed risk of bias. Random-effects models were used for quantitative synthesis.

RESULTS

Thirty-nine studies, mostly involving pediatric patients, reported consistent clinical and radiographic improvement after subtalar arthroereisis irrespective of implant material. Pooled single-arm analyses showed persistent sinus tarsi pain in 8.0% of metallic-implant cases and 6.3% of bioabsorbable-implant cases, and non-routine implant removal/revision in 7.7% and 5.2%, respectively. In the two comparative studies, metallic implants showed a trend toward higher odds of non-routine implant removal (pooled OR 2.20; 95% CI, 0.97-5.00) and significantly higher odds of persistent sinus tarsi pain (pooled OR 1.77; 95% CI, 1.03-3.03) compared with bioabsorbable devices. Radiographic correction and patient satisfaction were high in both groups, with no consistent evidence of superiority of either material.

CONCLUSIONS

Subtalar arthroereisis with metallic or bioabsorbable implants yields substantial clinical and radiographic improvement in pediatric flexible flatfoot. Available data suggest that bioabsorbable devices may be associated with lower rates of implant-related symptoms, but comparative evidence, limited to two non-randomized studies, is of low-to-moderate certainty. High-quality randomized trials with standardized, long-term outcome reporting are needed to define the optimal implant choice.