First metatarsophalangeal arthrodesis outcomes for hallux rigidus versus hallux valgus.

BACKGROUND: This study compared radiographic and functional patient outcomes of 1st MTP arthrodesis between hallux rigidus (HR) and hallux valgus (HV) cohorts. METHODS: A retrospective review was conducted at an academic medical center on patients who underwent 1st MTP arthrodesis during 2009-2021. In total, 136 patients (148 feet: HR=57, HV=47, combined=44) met the inclusion criteria of minimum three-month follow-up (mean=1.25 years, range=0.25-6.14 years). Data collection included patient-reported outcome measures (PROMs), radiographic markers, and complication and reoperation rates. RESULTS: PROMs improved overall, with HV patients significantly improving the least. The HR group had a significantly smaller improvement in HV angle (HR=-3.6, HV=-17, Combined=-15 p < .001), intermetatarsal angle (H=-0.16, HV=-2.8, Combined=-2.6 p < .001), and 1st-5th metatarsal width (HR=-0.98, HV=-4.6, Combined=-4.6, p < .001). Complication and reoperation rates did not differ by group. CONCLUSION: Outcomes of 1st MTP arthrodesis does not appear to differ between diagnostic indications of hallux rigidus, hallux valgus, or both. LEVEL OF EVIDENCE: Level III, Retrospective cohort study.