Effect on Foot Width With Triplanar Tarsometatarsal Arthrodesis for Hallux Valgus

BACKGROUND: Foot width reduction is a desirable cosmetic and functional outcome for patients with hallux valgus. Triplanar first tarsometatarsal (TMT) arthrodesis could achieve this goal by 3-dimensional correction of the deformity. The aim of this study was to evaluate changes in bony and soft tissue width in patients undergoing triplanar first TMT arthrodesis. METHODS: After receiving Institutional Review Board approval, charts were retrospectively reviewed for patients undergoing triplanar first TMT arthrodesis for hallux valgus at 4 institutions between 2016 and 2019. Patients who underwent concomitant first metatarsal head osteotomies (eg, Silver or Chevron) or fifth metatarsal osteotomies were excluded. Preoperative and postoperative anteroposterior weightbearing radiographs were compared to evaluate for changes in bony and soft tissue width. One hundred forty-eight feet from 144 patients (48.1 ± 15.7 years, 92.5% female) met inclusion criteria. RESULTS: Preoperative osseous foot width was 96.2 mm, compared to 85.8 mm postoperatively (P < .001). Preoperative soft tissue width was 106.6 mm, compared to 99.3 mm postoperatively (P < .001). Postoperatively, patients had an average 10.4 ± 4.0 mm reduction (10.8% reduction) in osseous width and average 7.3 ± 4.0 mm reduction (6.8% reduction) in soft tissue width. CONCLUSIONS: Triplanar first TMT arthrodesis reduced both osseous and soft tissue foot width, providing a desirable cosmetic and functional outcome for patients with hallux valgus. Future studies are needed to determine if patient satisfaction and outcome measures correlate with reductions in foot width. Level of evidence: Level III, retrospective comparative study