Impact of preoperative pes planus on orthopaedic implant removal following first metatarsophalangeal joint arthrodesis: A retrospective analysis.

First metatarsophalangeal (MTP) joint fusion is a frequently employed surgical treatment option for hallux rigidus and hallux valgus. Implant-related complications are common, necessitating further investigation into predisposing factors. The altered mechanics of pes planus may influence surgical outcomes; however, its direct impact on implant removal rates post-fusion remains unclear. We retrospectively analyzed the TriNetX US Collaborative Network database to identify patients undergoing first MTP joint arthrodesis by ICD-10 and CPT coding, the data was stratified by preoperative pes planus status. Implant removal rates were compared between pes planus (PP) and non-pes planus (noPP) cohorts. Odds ratios (OR) were calculated to assess associations. Patients in the PP cohort exhibited significantly higher rates of subsequent hardware irritation (OR 1.30, 95 % CI 1.010-1.675), and hardware removal (OR 1.27, 95 % CI 1.007-1.604) compared to patients in the noPP cohort. Our findings highlight patients with preoperative pes planus have significantly increased likelihood of implant irritation, removal, and reoperation following first MTP joint arthrodesis surgery. Biomechanical alterations associated with pes planus likely contribute to accelerated implant wear and compromise fusion stability leading to higher rates of future surgery.