Reduction of Foot Width with Triplanar Tarsometatarsal Arthrodesis for Hallux Valgus Deformity: A Multicenter Study

CATEGORY: Bunion; Hindfoot INTRODUCTION/PURPOSE: Foot width reduction is a desirable cosmetic and functional outcome for patients with hallux valgus. Triplanar tarsometatarsal (TMT) arthrodesis achieves this by three-dimensional correction of the deformity. The aim of this study was to evaluate changes in bony and soft tissue width in patients undergoing triplanar TMT arthrodesis. METHODS: After receiving IRB approval, charts were retrospectively reviewed for patients undergoing triplanar TMT arthrodesis for hallux valgus deformity at four institutions between 2016 and 2019. Patients who underwent concomitant first metatarsal head osteotomies (e.g., 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. Bony width was defined as the distance from the most medial aspect of the first metatarsal head to the most lateral aspect of the fifth metatarsal head. Soft tissue width was defined as the distance from the most medial soft tissue overlying the first metatarsal head to the most lateral soft tissue overlying the fifth metatarsal head. RESULTS: 148 feet from 144 patients (48.1 +- 15.7 years, 92.5% male) met inclusion criteria. Preoperative osseous foot width was 96.2 mm, compared to 85.8 mm postoperative (p < 0.001). Preoperative soft tissue width was 106.6 mm, compared to 99.3 mm postoperative (p < 0.001). Postoperatively, patients had an average 10.4 +- 0.33 mm reduction (10.8% reduction) in osseous width and average 7.3 +- 0.33 mm reduction (6.8% reduction) in soft tissue width. CONCLUSION: Triplanar TMT arthrodesis reduces 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.