First Metatarsophalangeal Arthrodesis Outcomes of Hallux Rigidus vs Hallux Valgus

CATEGORY: Midfoot/Forefoot; Other INTRODUCTION/PURPOSE: First metatarsophalangeal (MTP) joint arthrodesis is a commonly performed surgical procedure for patients with hallux rigidus (HR) or severe hallux valgus (HV). The purpose of this study was to compare patient outcomes of 1st MTP arthrodesis between HR and HV cohorts. We hypothesized that there would be no difference in patient-reported outcome measures (PROMs) or complication rates between groups. METHODS: A retrospective review was conducted at a single academic medical center of patients who underwent 1st MTP arthrodesis with one of two fellowship-trained foot and ankle orthopaedic surgeons between 2009 and 2021. A total of 136 patients (148 feet: HR=75, HV=47, both=44) met the inclusion criteria of the three-month follow-up minimum. Data collection included PROMs (i.e., Visual Analogue Scale [VAS], 12-item Short Form Survey [SF-12], Foot and Ankle Outcome Score [FAOS], and Foot and Ankle Ability Measure [FAAM], Patient-Reported Outcomes Measurement Information System [PROMIS]), radiographic markers, and complication and reoperation rates. The VAS, SF-12, FAOS, and FAAM were collected preoperatively; the FAOS and FAAM were collected postoperatively; and all were collected via prospective phone interview. Forty-six patients (50 feet: HR=21, HV=15, both=14) completed the phone interview at an average of 3.04 (range, 0.58-10.01) years postoperatively. Mean clinical follow-up was 1.25 (range, 0.25-6.14) years. RESULTS: The HR had a significantly smaller improvement in HVA (HR=-3.60, HV=-17.44, combined=-15.27; p<.001), IMA (HR=- 0.16, HV=-2.80, combined=-2.55; p<.001), and 1st-5th metatarsal width (HR=-0.98, HV=-4.59, combined=-4.60; p<.001). There was a trend toward improved PROMs, although only significant for all groups with the VAS (p<.001, p<.001, p<.001), FAOS Quality of Life (p<.001, p=.030, p=.001), and FAAM Activities of Daily Living (p<.001, p=.046, p=.002) and Total (p=.001, p=.024, p=.016) scores. The HV group significantly improved among the least PROMs. (Table 1) Complication (HR=28.07%, HV=38.30%, combined=36.36%; p=.499) and reoperation (HR=14.04%, HV=25.53%, combined=20.45%; p=.334) rates did not differ by group, although both were lowest for the HR group. Superficial infection (HR=12.28%, HV=17.02%, combined=9.09%; p=.521) and nonunion (HR=17.54%, HV=10.64%, combined=13.64%; p=.599) rates also did not differ. CONCLUSION: Indication for MTP arthrodesis does not appear to influence subjective outcomes of 1st MTP arthrodesis, as only one postoperative PROM differed between cohorts. All groups trended toward PROM improvements at 1-year and 3-years postoperative, although the HR group was the only group to continue improving from 1-year to 3-years postoperative. Thus, this study begins to provide insight into the role that specific forefoot pathology plays in 1st MTP arthrodesis outcomes, as we only found radiographic measures to be significantly different.