One-Month Postoperative Tibial Sesamoid Position Predicts Recurrence After Minimally Invasive Hallux Valgus Correction: A Retrospective Cohort Study

Background: The role of postoperative tibial sesamoid position (TSP) in hallux valgus (HV) recurrence remains controversial, and studies on its impact after third-generation minimally invasive HV surgery are limited. This study analyzed the association between postoperative TSP and outcomes after minimally invasive transverse distal metatarsal osteotomy (MITO) for HV correction. Methods: This retrospective cohort study included 118 patients who underwent MITO between July 2018 and August 2022 with ≥24 months of follow-up. Patients were grouped by 1-month postoperative TSP based on Hardy and Clapham classification (grades I-III: normal; grades IV-VII: outlier). Clinical outcomes were assessed using visual analog scale pain scores, Foot and Ankle Outcome Scores, and Medical Outcomes Study Short Form Health Survey-36 physical component summary scores. Radiologic evaluation included hallux valgus angle (HVA), first-to-second intermetatarsal angle (1-2 IMA), and TSP measurements. Recurrence and complications were also analyzed. Results: This study analyzed 165 feet (normal: 122 feet; outlier: 43 feet) with a mean follow-up of 35.6 months (range, 24-70 months). The outlier group showed consistently greater HVA (43.8 degrees vs 32.7 degrees preoperatively; 8.7 degrees vs 4.8 degrees at 1 month; 12.8 degrees vs 5.1 degrees at last follow-up), 1-2 IMA (15.6 degrees vs 13.0 degrees preoperatively; 5.7 degrees vs 3.7 degrees at 1 month; 6.6 degrees vs 4.5 degrees at last follow-up), and TSP (7 vs 6 preoperatively; 4 vs 2 at 1 month; 5 vs 2 at last follow-up) at all time points (all P < .001), with greater HVA increase from 1 month postoperatively to last follow-up ( P < .001). Functional scores improved similarly in both groups. On multivariable analysis, an outlier TSP at 1 month independently predicted recurrence (adjusted odds ratio 13.24, 95% CI 3.40-51.58), with good discrimination (area under the curve 0.838). Recurrence ( P < .001) and reoperation rates for symptomatic recurrence ( P = .017) were significantly higher in the outlier group. Conclusion: Postoperative TSP on anteroposterior standing radiographs at 1 month after surgery was associated with HV recurrence after MITO surgery. Precise correction of TSP may be essential to reduce the likelihood of HV recurrence.